KR101319822B1 - Method for recycling recovered organic hole material - Google Patents

Abstract

PURPOSE: A method for recycling a recovered organic hole material is provided to perform a refining process with high purity and high yield. CONSTITUTION: An organic hole material is bonded to a deposition element. The deposition element is dipped in an organic solvent containing solution. The deposition element is dissolved in the organic solvent containing solution. The foreign substance is filtered and removed. A melting temperature for removing the foreign substance is 100 to 180°C.

Description

Recycling method of recovered organic hole material {METHOD FOR RECYCLING RECOVERED ORGANIC HOLE MATERIAL}

The present invention relates to a method for recycling the recovered organic hole material, and more particularly, after the deposition process in the organic EL panel manufacturing process, the organic hole material is collected by a cleaning or physical method in a deposition element, an adhesion plate, a crucible, etc. In addition, the first purification process is performed so that the purity of the organic hole material is at least 99.90%, and then the second purification process is performed to reduce the impurity content and at least 99.95% high purity of the organic hole material having low solubility in the organic solvent. And a method for recycling organic hole materials obtained in high yield to enable reuse as organic materials.

In the organic EL panel display device, a thin film layer of a light emitting material is stacked on a transparent glass substrate. In the light emitting material thin film layer, light of a specific wavelength due to energy difference is generated when holes supplied from the hole injection electrode and electrons supplied from the electron injection electrode are combined in the light emitting layer to form excitons and fall from the formed excitons to the ground state. It is a self-luminous display device which displays an image using the phenomenon which arises.

The organic EL panel has an organic light emitting diode (OLED) and displays it as a self-luminous type, so that it does not require a separate light source, thereby reducing its thickness and weight.

In addition, the organic EL panel is expected to be a next generation display device because it can be driven with low power consumption, is light and thin, has high luminance, wide viewing angle, and fast response speed.

The light emitting material is deposited on the hole injection layer, the hole transport layer, the main light emitting layer of the red / green / blue light emitting layer, the electron transport layer, and the electron injection layer to be shaped on the glass substrate.

At this time, the light emitting material is mounted on a thin metal plate (shadow mask) to produce an organic EL panel by depositing only on the open window portion. For example, in the beginning, red is deposited and the mask is moved in small increments in the order of green and blue.However, the method of raising the red, green and blue pigments by moving the open mask in small increments is a common method of low molecular organic panel. It is a full color recipe.

However, when the luminescent material is vacuum deposited on the glass substrate, the amount deposited on the substrate to be deposited is less than 10% (w / w) of the initially used luminescent material input amount, and the rest is other components of the deposition apparatus other than the substrate. In other words, deposited on the deposition plate, the angle control plate, the crucible and the like, the actual material usage is 5% and about 95% is discarded.

At present, the light emitting materials are scraped together with a metal spatula, and vacuum evaporation is used to improve the quality. However, the thickness of the deposited film is thin and the deposition surface of the deposition plate is made of a metal mesh. In addition, since the low purity of the collected low-purity product is directly evaporated without further purification to make a high-purity product, several times of vacuum evaporation must be performed, yields are extremely low and cost is not successful.

Korean Patent No. 1268916 by the present applicant proposes a method of sublimation and purification after collecting and recovering the light-emitting material in the deposition apparatus by scraping or extracting with a solvent, and then separated and purified by a column filled with the adsorptive resin, When the impurities are separated by the elution method by the adsorptive resin, the target material and the impurities overlap depending on the number of uses of the adsorbent resin and the type of the impurity. As a result, difficulties in proceeding and lowering of the yield during sublimation occur. In general, when a light emitting material is vacuum-deposited on a glass substrate, a sublimation-purified product is used to remove metal components and improve purity.

In an effort to solve such a problem, there is a demand for a method of increasing the deposition rate of the light emitting material or efficiently recovering the light emitting material from the deposition apparatus deposited other than the substrate. How to do it is desperately needed.

In particular, the organic hole material is used alone or in combination with the red / green / blue light emitting material to increase the luminous efficiency of the red / green / blue light emitting material of the main light emitting layer, depending on the degree of impurities contained in the organic EL panel may be affected. It is an important material that can be.

In addition, since the vacuum evaporation melts and decomposes at a high temperature of 200 to 300 ° C. for several hours, a dopant is added to increase luminous efficiency, and a mixed material is sometimes used. Various impurity components are mixed in a large amount, and in particular, organic hole material is decomposed itself and various impurities are present.

Moreover, organic hole materials have no selectivity for removing impurities due to their extremely low solubility in various solvents.

In addition, after completion of the deposition process, a sublimation purification process is performed in order to reuse the organic material cleaned or physically recovered from the deposition apparatuses, not the substrate, as the organic EL panel material. Due to the low solubility, it is not removed in the sublimation purification process and thus cannot be reused as an organic EL material.

Accordingly, the present inventors have tried to efficiently recover, separate, and purify the organic hole material having a very low solubility in organic solvents among the light emitting materials discarded after the vacuum deposition process of the organic light emitting layer when manufacturing the organic EL panel, pyrrolidone-based After immersing in the organic solvent-containing solution and completely dissolving the solution temperature, the temperature was lowered again to remove the impurities by filtration to remove the impurities, thereby performing the first purification step so that the purity of the organic hole material was at least 99.90%. The present invention was completed by performing a second purification process to obtain purified organic hole material in high purity and high yield of 99.95% or more and at the same time reducing impurities.

It is an object of the present invention to efficiently recover organic light-emitting materials having low recovery rate, and to recycle them with high purity and high yield, which are very expensive in light emitting materials discarded after the vacuum deposition process of the organic light emitting layer. It is to provide a method for recycling the recovered organic hole material.

In order to achieve the above object, the present invention after collecting the organic hole material from the deposition element with the organic hole material, after the deposition process in the organic EL panel manufacturing process, the collected material is immersed in a pyrrolidone-based organic solvent-containing solution After dissolving and filtering the foreign matter, the obtained filtrate was cooled and the purity of the precipitated organic hole material was carried out to be at least 99.90%, and the dissolution temperature was 100 to 180 ° C. A first purification process performed at a low to 100 ° C. condition; And performing a secondary purification step of cooling and precipitation of the filtrate obtained by immersing and re-dissolving the organic hole material obtained after the first purification step in a pyrrolidone-based organic solvent-containing solution, and (1) purity of the purified organic hole material Is 99.95% or more, and (2) a method for recycling the recovered organic hole material, wherein each impurity content is 0.05% or less.

More preferably, through the recycling method of the recovered organic hole material of the present invention, (1) the purity of the purified organic hole material is 99.965% or more, (2) each impurity content is 0.035% or less, and (3) the yield By obtaining this 80% or more, it can be reused.

In the method of the present invention, the solution used in the primary and secondary purification process is selected from the group consisting of methyl pyrrolidone, 2-pyrrolidone, dimethyl imidazolidinone and vinyl pyrrolidone alone or those It is a pyrrolidone-based organic solvent in a mixed form of the liver, and the pyrrolidone-based organic solvent is used at a ratio of 10 to 40 times (v / w) to the weight of the organic hole material.

More preferably, in order to improve the low solubility of the organic hole material, the solution uses a mixed solvent in which a pyrrolidone-based organic solvent is mixed with an aromatic organic solvent selected from toluene or xylene.

In the method of the present invention, the primary refining step is an organic hole by immersing and dissolving in a solution, and then filtered using any one adsorbent selected from the group consisting of diatomaceous earth, silica gel, alumina, activated carbon, sand and polymer resin, The purity of the material can be adjusted to be at least 99.90%.

In addition, the method for recycling the recovered organic hole material of the present invention, after recovering the mixture containing the organic hole material attached to the deposition element before the first purification step, after the deposition step, ethyl acetate, toluene, xylene, chloride A preliminary step of selectively separating organic hole materials may be further performed by filtering after reflux in a solvent of 90 to 100 times (v / w) alone or in a mixed form selected from the group consisting of methylene, dichloroethane, acetone and tetrahydrofuran. have.

According to the present invention, an expensive organic light emitting material discarded after the vacuum deposition process of the organic light emitting layer in the manufacturing process of the organic EL panel display device, in particular, has a very low solubility in organic solvents, and efficiently recovers an organic hole material having a low recovery rate and It can provide a method that can be purified and reused in high yield.

Therefore, the organic hole material with purity of 99.95% or higher and the impurity content of 0.05% or less can be obtained and reused according to the method of the present invention. Can contribute to

1 is a result of HPLC analysis of the crude organic hole material recovered from the deposition apparatus of the present invention,
Figure 2 is a HPLC analysis of the final organic organic material purified according to the method of the present invention.

Hereinafter, the present invention will be described in detail.

According to the present invention, after the deposition process in the organic EL panel display device, the organic element is deposited by immersing and dissolving a deposition element having an organic hole material in a pyrrolidone-based organic solvent-containing solution, and filtering and depositing the filtrate. A primary refining process performed at a purity of at least 99.90%, wherein the dissolution temperature is 100 to 180 ° C., and when the filtration and removal of foreign matters is performed at a temperature of 80 to 100 ° C. lower than the dissolution temperature; And performing a secondary purification step in which the filtrate obtained by immersing and re-dissolving the organic hole material obtained after the first purification step in a solution containing pyrrolidone-based organic solvent is cooled and precipitated, (1) purity of the purified organic hole material Is 99.95% or more, and (2) a method for recycling the recovered organic hole material, wherein each impurity content is 0.05% or less.

The organic hole material in the present invention includes HT-051 or C-023 commonly used in the art, and includes candidate materials that can be used as other organic hole materials. At this time, the organic hole material is difficult to recover and reuse due to the low solubility in the organic solvent, the organic EL panel may be defective depending on the degree of impurities contained in the organic hole material, the method of the present invention It aims to improve the purity and yield of materials and to reduce the content of impurities.

1 is a HPLC analysis result of the crude organic hole material recovered from the deposition apparatus after the deposition process in the organic EL panel manufacturing process of the present invention, the purity of the crude organic hole material (HT-051) is 99.8751% (HPLC 7 component peak) and two impurities observed in HPLC 10 component peak and 5 component peak are observed as 0.0970% and 0.0279%, respectively.

In addition, Figure 2 shows the results of HPLC analysis of the final purified organic hole material according to the method of the present invention, the purity of the organic hole material (HT-051) 99.968% (HPLC 7-component peak), HPLC 10-component peak impurities 0.0298 % And 5 minute peaks of 0.0021% of impurities are observed.

That is, through the recycling method of the recovered organic hole material of the present invention, (1) the purity of the purified organic hole material is 99.965% or more, (2) each impurity content is 0.035% or less, and (3) the yield is 80 More than% can be obtained [ Table 2 ].

Therefore, the first purification step of the method for recycling the recovered organic hole material of the present invention, after the deposition process in the organic EL panel manufacturing process, the material is collected from the deposition element to which the organic hole material is attached, and the collected organic hole material is organic The resulting filtrate is cooled by immersing and dissolving in a solvent solution, filtering off the foreign matter, and performing a purity of at least 99.90%.

Usually, the solubility of the recovered organic hole material is as low as 3 to 5 mg / ml in methylene chloride and toluene, so that an organic solvent having solubility is limited.

Therefore, in order to obtain the purity of the organic hole material at least 99.90% or more in the first purification step of the present invention, it is carried out in a pyrrolidone-based organic solvent-containing solution as an organic solvent that can improve the low solubility of the organic hole material. .

Preferred examples of the pyrrolidone-based organic solvent may be used alone or a mixture thereof selected from the group consisting of methyl pyrrolidone, 2-pyrrolidone, dimethyl imidazolidinone and vinyl pyrrolidone. In the exemplary embodiment of the present invention, the N-methyl pyrrolidone (NMP) is described as being limited, but is not limited thereto.

At this time, the amount of the pyrrolidone-based organic solvent is used in a ratio of 10 to 40 times (v / w) relative to the weight of the organic hole material. When the pyrrolidone-based organic solvent is used in less than 10 times (v / w) ratio, the solubility of the organic hole material is low, impurities and organic hole material are removed together during filtration, causing a decrease in yield, 40 times (v / w) When used in excess of the w) ratio, the solubility of the organic hole material and the impurities is high, so that the removal of impurities is difficult and the yield decreases into the mother liquor.

In the first purification step, when the organic hole material is dissolved in the above solution, the temperature of the solution is raised to 100 to 180 ° C. to completely dissolve the work, thereby increasing the recovery amount of the organic hole material.

If the dissolution temperature of the solution is less than 100 ℃ in the above, the solubility is low, the complete dissolution is insufficient, if it exceeds 180 ℃, the color of the product is changed and decomposed is not preferable.

In addition, by increasing the dissolution temperature of the sole or mixed solvent of the pyrrolidone-based organic solvent in the first purification step, the solubility of the organic hole material can be increased, and then in a condition of 80 to 100 ℃ lower than the dissolution temperature of the solution By filtering, impurities are precipitated and removed, so that the purity and yield of the organic hole material can be increased.

According to the amount of the organic solvent and the dissolution temperature of the solution in the pyrrolidone-based organic solvent-containing solution in the above-described first purification step, the purity of the organic hole material is at least 99.90%, and the impurity content is controlled [ Table 3 ].

In addition, as a preferable organic solvent, the pyrrolidone-based organic solvent, it may be carried out under mixed solvent conditions in which an aromatic organic solvent such as toluene or xylene is mixed.

Another method for additionally improving the purity of the organic hole material to 99.90% or more in the primary refining process of the present invention, which is composed of diatomaceous earth, silica gel, alumina, activated carbon, sand and polymer resin after immersion and dissolution in the solution. The purity of the organic hole material, which is subjected to primary purification by adsorbing and removing impurities by using one of the adsorbents selected from the group, can be achieved at 99.90% or more and 0.05% or less of impurities at the HPLC 10-minute peak [ Table 4 ].

According to the method of the present invention, after the first purification step, a second purification step of immersing and re-dissolving the obtained organic hole material in a solution made of a pyrrolidone-based organic solvent to cool and precipitate.

In this case, as the pyrrolidone-based organic solvent, the same as described in the first purification step, in the embodiment of the present invention limited to N-methyl pyrrolidone (NMP) described, but not limited to 2-pyrrolidone , Dimethyl imidazolidinone and vinyl pyrrolidone may be used alone or in combination thereof.

In addition, the dissolution temperature conditions of the solution is the same as that performed in the first purification step. After dissolving at the dissolution temperature, the mixture is cooled to room temperature and then filtered and dried.

Furthermore, the method for recycling the recovered organic hole material of the present invention recovers the mixture including the organic hole material attached to the deposition element before the first purification step and after the deposition step, and collects the organic hole material into the collected organic hole material. Low-solubility of ethyl acetate, toluene, xylene, dichloroethane, methylene chloride, acetone and tetrahydrofuran, the solvent alone or in a mixed form selected from the group consisting of 90 to 100 times (v / w) after filtering the organic hole A preliminary step of selectively separating the material may be further performed to ensure that the purity of the organic hole material is at least 99.90% during the primary refining process.

Through the above steps, (1) the purity of the purified organic hole material is 99.965% or more, each content of impurities is 0.035% or less, and (3) the yield is 80% or more.

Accordingly, the method for recycling the recovered organic hole material of the present invention is a method for efficiently recovering and reusing an expensive organic hole material that is discarded and lowering an impurity content, thereby contributing to cost reduction in manufacturing an organic EL panel.

Hereinafter, the present invention will be described in more detail with reference to Examples.

This is for further illustrating the present invention, and the scope of the present invention is not limited to these examples.

< Example  1> Of organic hole materials  Separate Purification Method

After scraping off the deposition plate and crucible to recover the organic hole material (HT-051) was carried out by HPLC analysis in accordance with the conditions of Table 1 below.

The HPLC analysis results are shown in FIG. 1, and more specifically, the product purity of the recovered organic hole material (HT-051) was observed to be 99.87% at the HPLC seven-minute peak, and as an impurity not removed from the sublimation tablets, The retention times and contents of the two impurities were observed as 0.0970% at the 10-minute peak and 0.0279% at the HPLC 5-minute peak.

Immediately after the recovery, 10 g of the organic raw material, which was purified by the primary refining method, was placed in 300 ml of NMP (30 times the weight of the organic hole material), heated to 125 ° C, completely dissolved, cooled, and filtered to dissolve foreign materials that do not melt at 80 ° C. The obtained filtrate was cooled to room temperature, and the precipitated crystals were dried to obtain 9.0 g of a primary purified product. In this case, as a result of HPLC analysis, the purity of the first purified organic hole material was 99.93%, and 0.0495% of impurities in the HPLC 10-minute peak and 0.0130% of the impurities in the HPLC 5-component peak were confirmed.

Subsequently, 9.0 g of the first purified organic hole material was re-added to 270 ml of NMP by a second purification method, heated to 125 ° C., completely dissolved, cooled to room temperature, filtered, and dried to obtain 8.2 g of second purified organic hole material. Got. In this case, as a result of HPLC analysis, the purity of the second purified organic hole material was 99.968%, and 0.0298% of impurities in the HPLC 10-minute peak and 0.0021% of the impurities in the HPLC 5-component peak were confirmed.

From the above, the peak which was not removed in the sublimation purification process was refine | purified over 2 times, and it obtained in high purity.

< Example  2 to 4> Impurity Removal Rate by Repeated Purification

The organic hole material (HT-051) of each crude product recovered from the deposition apparatus was purified in the same manner as in Example 1 above, and then the impurity concentration (%) was measured. At this time, the impurity concentration (%) of the HPLC 10-minute peak measured for each cycle is shown in Table 2 below.

As confirmed in the results of Table 2, the purification of the organic hole material was confirmed as the impurities of the HPLC 10-component peak were removed at a concentration of less than 0.03% when purified twice. In addition, while impurities of the 10-minute peak were removed, impurities of the HPLC 5-component peak were also purified to less than 0.003% in two purifications.

< Example  5 ~ 8> Purification efficiency according to solvent usage and dissolution temperature

The first purification was carried out in the same manner as in Example 1, except that the first purification process performed in Example 1 was performed according to the conditions shown in Table 3 below.

Specifically, 10 ml of NMP (10 times, v / w) in 10 g of the recovered organic hole material (HT-051) (99.896% purity, 0.0599% impurity in HPLC 10-minute peak, 0.0122% impurity in HPLC 5-minute peak) After dissolving the product at a temperature of 178 ° C. and dissolving the product, the foreign matter was filtered off at 100 ° C., cooled to room temperature, filtered, washed, and dried to obtain 8.9 g of a first purified organic hole material. As a result of HPLC analysis, the purity of the organic hole material was 99.940%, and it was confirmed that the impurities of the HPLC 10-minute peak were 0.0468% and the HPLC 5-component peak was 0.0078%.

According to the conditions shown in Table 3 below, the organic hole material was first purified as in Example 1.

< Comparative Example  1 to 2>

Solvent usage and dissolution temperature conditions were the same as in Example 1 except that the first purification was carried out except that the conditions shown in Table 3.

As confirmed in Table 3, when the recovered organic hole material is first purified, impurities in HPLC 10-minute peak and impurities in HPLC 5-minute peak are used within the dissolution temperature conditions for the amount of the organic solvent used in Table 3 and the solution. Was removed to 0.05% or less. In addition, the amount of the organic solvent is most preferably 30 and 40 times (v / w) relative to the weight of the material, in terms of yield and removal of impurities.

On the other hand, when 50 times (v / w) of solvent NMP was used (Comparative Example 1), the yield was low, and when the dissolution temperature was performed at a high temperature of 200 ° C. (Comparative Example 2), decomposition occurred and the purity was high. Decreased to 99.913%.

< Example  9-12> Effect of Adsorbent

The first purification was carried out in the same manner as in Example 1, except that the first purification process performed in Example 1 was carried out according to the conditions shown in Table 4 below.

10 g of organic hole material (HT-051) (99.86% purity, 0.11% impurity of HPLC 10-minute peak) was added to 300 ml of NMP, heated to 125 ° C, completely dissolved, 5 g of diatomaceous earth was added, and stirred at the same temperature for 1 hour. After filtration at a temperature of 100 ℃ and washed with 20ml NMP. The filtrate was cooled and the precipitated crystals were dried to yield 8.7 g of the first purified organic hole material. At this time, the purity of the first organic purified material purified by HPLC analysis was 99.93%, it was confirmed that the impurities of the HPLC 10-minute peak 0.046%.

According to the conditions shown in Table 4 below, the organic hole material was first purified as in Example 1.

As confirmed in Table 4, when various adsorbents were used, the removal effect was confirmed while maintaining the yield.

< Example  13> Purification efficiency according to mixed solvent

10 g of the recovered organic hole material (HT-051) (99.89% purity, 0.07% impurity of HPLC 10-component peak) was added to a mixed solvent of 250 ml of NMP and 750 ml of toluene in the first purification method, and then dissolved at 110 ° C. Then, the process was performed in the same manner as in Example 1 to obtain 7.8g of organic hole material with 99.96% purity.

< Example  14> From mixed organic materials Of organic hole materials  Separation tablet

The organic organic material (HT-051), the blue light emitting material (GBH-X16) and the dopant are mixed with and recovered the mixed organic material from the adhesion plate, and the HPLC analysis of the collected material shows the purity of the organic hole material ( HT-051) 72%, the blue light emitting material (GBH-X16) 23% and the dopant including the dopant was confirmed that the sum of 5%.

In order to recover the organic hole material (HT-051) from the recovered mixture, ethyl acetate 1,000 having a low solubility of the organic hole material (HT-051) and a high solubility of the blue light emitting material (GBH-X16) and the blue dopant. 10 g of the mixture was added to mL, and the mixture was refluxed for 10 hours. After filtering, the insoluble substance was separated and dried to obtain 6.5 g of organic hole material (HT-051). At this time, the purity analysis results were 99.86% of organic hole material (HT-051), 0.04% of blue light emitting material (GBH-X16), the remaining 0.10%.

The obtained organic hole material (HT-051) was performed in the same manner as in Example 1 to obtain an organic hole material (HT-051) having an impurity purity of 300 ppm or less and a purity of 99.96%.

< Comparative Example  3>

The purified organic hole material (HT-051) has a product purity of 99.87%, and 1 g of a crude product identified as 0.1% impurity of HPLC 10-minute peak and 0.03% of 5-minute peak is placed in 125 ml of xylene (temperature). The solution was completely dissolved, cooled to room temperature and filtered to obtain 0.7 g of a primary purified organic hole material (HT-051). In this case, as a result of HPLC analysis, the purity of the first purified organic hole material was 99.91%, and the impurities of the HPLC 10-component peak were found to be 0.060%.

0.7 g of the organic hole material obtained after the first purification was added to 88 ml of xylene, dissolved to raise the temperature, and cooled to room temperature. The purity of the deposited 5 g of the second purified organic hole material was 99.92%, and impurities of HPLC 10-minute peak were 0.057. As a percentage, impurities were removed in the first purification process, but when recrystallized in the second step, the yield was lowered, and it was confirmed that the impurity removal had no significant effect.

< Comparative Example  4 ~ 8> Purification efficiency according to solvent type

Instead of the solvent used in Comparative Example 3, except for performing in each single solvent conditions selected from toluene, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), methylene chloride or chloroform, the comparative example The same was carried out as 3.

As a result, in the case of using the solvent, an excess solvent should be used to dissolve the organic hole material (HT-051).

< Comparative Example  9>

10 g of the recovered organic hole material (HT-051) (purity 99.89%, HPLC 10-minute peak impurity 0.07%) was added to a mixed solvent of NMP 250 ml and toluene 750 ml, and the temperature was dissolved. The precipitated crystals were removed, cooled to 60 ° C., and the precipitated crystals were filtered and dried at 60 ° C. to obtain 5 g. At this time, the HPLC analysis showed that the purity of the organic hole material was 99.97%, and the impurities of the HPLC 10-minute peak were 0.0245%, but the yield was low at 58%, which shows that the product should be filtered after cooling to room temperature.

As described above, the present invention is a material which is discarded after the vacuum deposition process of the organic light emitting layer in the manufacturing process of the organic EL panel display device, and is particularly expensive, and has an extremely high solubility in organic solvents and thus has low recovery rate. It provides a method that can be recovered and purified in high yield and reuse.

Therefore, in the present invention, after the deposition process, the organic hole material is collected from the deposition plate, crucible, etc. with the organic hole material by washing or physical method, and the purification process is repeated to lower the impurity content and lower the solubility in the organic solvent. The organic hole material can be recovered and purified with high yield and high purity to provide a recycling method of the organic hole material that can be reused as an organic material, thereby reducing the cost of manufacturing the organic EL panel.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.

Claims (7)

After the deposition process in the manufacturing process of the organic EL panel display device, the deposition element with the organic hole material is immersed in a solution containing a pyrrolidone-based organic solvent to dissolve it, and the filtrate is cooled to precipitate the organic filtrate. Purification is carried out to be at least 99.90%, the melting temperature is 100 to 180 ℃, when the filtration of the foreign matter is carried out under the conditions of 80 to 100 ℃ lower than the melting temperature; And
Performing a second purification step of cooling and precipitation of the filtrate obtained by immersing and re-dissolving the organic hole material obtained after the first purification step in a pyrrolidone-based organic solvent-containing solution,
(1) The purity of the purified organic hole material is 99.95% or more,
(2) A method for recycling the recovered organic hole material, wherein the impurity content is 0.05% or less. 2. The recovered organic composition according to claim 1, wherein (1) the purity of the purified organic hole material is 99.965% or more, (2) each impurity content is 0.035% or less, and (3) the yield is 80% or more. Recycling method of hole material. The method of claim 1, wherein the pyrrolidone-based organic solvent-containing solution contains a single or mixed form selected from the group consisting of methyl pyrrolidone, 2-pyrrolidone, dimethyl imidazolidinone and vinyl pyrrolidone Recycling said recovered organic hole material. The method of claim 1, wherein the pyrrolidone-based organic solvent is used at a ratio of 10 to 40 times (v / w) to the weight of the organic hole material. The method of recycling the recovered organic hole material according to claim 1, wherein the pyrrolidone organic solvent-containing solution is further mixed with an aromatic organic solvent selected from toluene or xylene. According to claim 1, After immersing and dissolving in the solution in the first purification step, characterized in that the filtered using any one adsorbent selected from the group consisting of diatomaceous earth, silica gel, alumina, activated carbon, sand and polymer resin. Recycling method of the recovered organic hole material. The method of claim 1, wherein before the first purification process, after recovering the mixture comprising the organic hole material attached to the deposition element after the deposition process, ethyl acetate, toluene, xylene, methylene chloride, dichloroethane, acetone and tetrahydro The recovered organic holes, characterized in that further performing a preliminary step of selectively separating the organic hole material by filtering after reflux at 90 to 100 times (v / w) of a solvent selected from the group consisting of furan at 90 to 100 times (v / w) How to recycle the material.

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