Method for producing a hole transport layer compound having high purity and high molecular weight

Abstract

Disclosed is a method for producing a hole transport layer compound. The method can obtain a poly(triarylamine) polymer having high purity and high molecular weight as a hole transport layer compound.

Description

Technical Field

[0001] This invention relates to a method for manufacturing hole transport layer compounds, and more specifically, to a method for obtaining high-purity, high-molecular-weight poly(triarylamine) polymers as hole transport layer compounds. Background Technology

[0002] Poly(triarylamine) (PTAA) is a representative hole transport material used in perovskite solar cells. Despite the use of various hole transport materials, PTAA is considered the most suitable compound for large-area solar cell applications because it ensures both stability and efficiency of the solar cell module. However, while PTAA can be successfully synthesized and purified on a laboratory scale, scaling up its synthesis and purification to mass production levels presents several technical challenges.

[0003] First, poly(triarylamine) (PTAA) is typically synthesized using Suzuki polymerization. This synthetic method requires a palladium catalyst, phosphine ligands, and an excess of inorganic base. While this is not a significant problem in general small-molecule synthesis, the presence of excess residual metals within the compound intended to function as a hole transport layer (HTL) diminishes its performance as a hole transport layer. On a laboratory scale, purification using Soxhlet extraction involves lengthy purification processes. However, implementing this equipment on a large-scale production scale is impractical and lacks reproducibility. In particular, Soxhlet extraction is considered a heterogeneous purification system because the distilled organic solvents often fail to adequately dissolve PTAA. That is, during the precipitation process, metals can be trapped or accumulate within the polymer, resulting in high residual metal content.

[0004] Second, since PTAA is a polymer, ensuring a high molecular weight and a narrow polydispersity index (PDI) is crucial to its performance. To ensure consistent polymerization conditions, the palladium catalyst needs to possess consistently stable catalytic activity. Because palladium catalysts are prone to oxidative deactivation upon exposure to atmospheric oxygen, it is essential to introduce feedstocks at the start of polymerization while isolating the reaction system from the atmosphere. In particular, when solid feedstocks are introduced through the reactor manhole, the palladium catalyst is inevitably exposed to air, and this exposure is highly inconsistent in typical manufacturing environments.

[0005] To address these issues, nitrogen purging and bubbling are typically used to isolate the reactants from the atmosphere. However, as the reaction scale increases, the palladium catalyst becomes more exposed to the atmosphere during the introduction of the reaction solvent and solid reactants into the reactor, making it challenging to achieve reproducible polymerization results despite prolonged nitrogen bubbling. Therefore, a system is needed that, in addition to nitrogen bubbling before polymerization, can also replace the internal atmosphere of the reactor with nitrogen during the introduction of solid reactants. Summary of the Invention

[0006] Technical issues

[0007] The hole transport layer (HTL) of perovskite solar cells is a critical material determining cell efficiency and constitutes the largest portion of the raw materials. Therefore, the hole transport layer must be used solely to transport holes generated in the light-absorbing layer to the electrodes and must be free of impurities other than added dopants. However, unless a separate post-polymerization process is performed, excess metal salts will remain, which can interfere with the hole transport function of the dopants. Therefore, a metal purification process utilizing a homogenization purification system becomes essential.

[0008] Furthermore, due to the nature of organic polymers, achieving a narrow polydispersity index (PDI) and high molecular weight is crucial for ensuring consistent performance. Since the hole transport layer material is positioned on the perovskite light-absorbing layer (in the nip structure), the hole transport layer not only functions to transport holes but also protects the light-absorbing layer. Given the importance of protecting the light-absorbing layer, the hole transport layer must be formed of a material that can withstand heat and moisture. Therefore, to prepare PTAA compounds with a narrow PDI and high molecular weight, a system is needed that is independent of nitrogen purging and bubbling before polymerization and can also replace the internal atmosphere of the reactor with nitrogen during the loading of solid reactants.

[0009] Technical solutions

[0010] According to one aspect of the present invention, a method for manufacturing a hole transport layer compound represented by Formula 1 is provided:

[0011] [Formula 1]

[0012]

[0013] Where R 1 R 2 and R 3 Each is independently hydrogen or C1 to C 10 alkyl,

[0014] The method includes: polymerizing a hole transport layer compound by introducing raw materials and a catalyst into a vacuum transfer (VT) system and then polymerizing it; and mixing the polymerized hole transport layer compound with an ion exchange resin to remove reaction impurities.

[0015] Preferably, the vacuum transfer system includes:

[0016] The main reactor is loaded with the raw materials and the catalyst;

[0017] Sub-reactor, loaded with solvent; and

[0018] The VT line connects the main reactor to the sub-reactor.

[0019] Preferably, the VT pipeline includes:

[0020] The intermediate pipeline has an inlet.

[0021] The main pipeline branches off from the intermediate pipeline and connects to the main reactor;

[0022] Sub-pipelines branch off from the intermediate pipeline and connect to the sub-reactor;

[0023] An intermediate valve is installed on the intermediate pipeline;

[0024] The main valve is located on the main pipeline; and

[0025] Sub-valve, installed on the sub-pipeline.

[0026] Preferably, the step of polymerizing the hole transport layer compound includes:

[0027] The raw materials and the catalyst are introduced into the main reactor, and then the main reactor is connected to the main pipeline;

[0028] The solvent is introduced into the sub-reactor, and then the sub-reactor is connected to the sub-pipeline;

[0029] With the intermediate valve, the main valve, and the sub-valve closed, connect the vacuum line to the inlet of the intermediate line, and open the intermediate valve, the main valve, and the sub-valve to evacuate the main reactor and the VT line, then close the intermediate valve.

[0030] Open the sub-valve to move the solvent to the main reactor; and

[0031] When the solvent movement is complete, the sub-valve is closed, the intermediate valve is opened, and the main reactor and the VT pipeline are purged with nitrogen gas, thereby initiating the polymerization reaction.

[0032] Preferably, the sub-reactor, in which the solvent is introduced, is cooled after being connected to the sub-pipeline, and

[0033] Before moving the solvent, the temperature of the sub-reactor is raised to room temperature while the main reactor is cooled, so that the solvent can evaporate in the sub-reactor and move to the main reactor.

[0034] Preferably, the polymerized hole transport layer compound is mixed with a cationic or anionic resin, followed by stirring and filtration to remove reaction impurities.

[0035] Preferably, the reaction impurities are removed by: mixing the polymerized hole transport layer compound with the cationic resin and stirring and filtering the resulting mixture; subsequently, mixing the filtered product with the anionic resin and stirring and filtering the resulting mixture, or...

[0036] The polymerized hole transport layer compound is mixed with the anion exchange resin, and the resulting mixture is stirred and filtered. The filtered product is then mixed with the cationic resin, and the resulting mixture is stirred and filtered.

[0037] Preferably, the cationic resin comprises a polymer containing sulfonic acid functional groups or carboxylic acid functional groups, and

[0038] The anion exchange resin comprises a polymer containing quaternary ammonium salt functional groups or tertiary ammonium salt functional groups.

[0039] Preferably, the hole transport layer compound represented by Formula 1 is obtained by the following method:

[0040] The polymerization of compounds represented by Formula 2 and Formula 3, or the polymerization of compounds represented by Formula 4.

[0041] [Equation 2]

[0042]

[0043] [Formula 3]

[0044]

[0045] [Formula 4]

[0046]

[0047] In equations 1 to 3, R 1 R 2 and R 3 Each is independently hydrogen or C1 to C10 alkyl,

[0048] In equations 2 and 4, X is independently I, Br, Cl, or OTf, and,

[0049] In equations 3 and 4, R 4 Each is independently hydrogen or C1 to C5 alkyl, or,

[0050] In equations 3 and 4, R 4 Each is independently a C1 to C5 alkyl group, with two Rs. 4 Groups are linked together to form cyclic alkyl groups.

[0051] Preferably, the phosphine ligand, phase transfer catalyst, and base are further introduced into the main reactor.

[0052] Preferably, the hole transport layer compound has a number average molecular weight (Mn) of 18 kDa or greater, a weight average molecular weight (Mw) of 33 kDa or greater, and a polydispersity index (PDI) of 3.7 or less.

[0053] According to another aspect of the present invention, a hole transport layer compound manufactured by the above-described method for manufacturing a hole transport layer compound is provided.

[0054] According to another aspect of the present invention, a hole transport layer made of the above-described hole transport layer compound is provided.

[0055] Beneficial effects

[0056] Embodiments of the present invention provide a method for manufacturing hole transport layer (HTL) compounds, wherein the method ensures the production of high-purity poly(triarylamine) (PTAA) compounds by removing unreacted organic matter and metal salts at a mass production scale.

[0057] Embodiments of the present invention provide a homogenization purification system that ensures consistent inert conditions during the polymerization of poly(triarylamine) (PTAA) compounds.

[0058] In addition, the homogenization purification system allows for the maintenance of homogenization polymerization conditions, thereby providing a polymerization system capable of achieving both high molecular weight and narrow polydispersity index (PDI).

[0059] Embodiments of the present invention provide a method for manufacturing an HTL compound, wherein the method enhances the thermal stability and hydrophobicity of the PTAA compound by increasing the molecular weight of the PTAA polymer, thereby improving the high-temperature stability of the hole transport layer formed by the PTAA compound and reducing the hygroscopicity of the hole transport layer.

[0060] Embodiments of the present invention provide a method for manufacturing an HTL compound, wherein the method enhances the intermolecular interactions (π-particles) of the PTAA compound by increasing the molecular weight of the PTAA polymer. (π stacking), thereby ensuring that the hole transport layer formed by the PTAA compound has improved conductivity and superior charge transfer capability.

[0061] Embodiments of the present invention provide a vacuum transfer system that can maintain inert conditions by effectively removing oxygen from the reactor, even when the reactor interior is exposed to the atmosphere for extended periods during raw material loading. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the vacuum transfer (VT) system according to the present invention.

[0063] Figure 2 This is a diagram of the VT pipeline in the vacuum transfer system.

[0064] Figure 3 The hole transport layer compound prepared in Example 1 according to the present invention is shown. 1 H nuclear magnetic resonance (NMR) results.

[0065] Figure 4 The hole transport layer compound prepared in Example 1 according to the present invention is shown. 13 C NMR results.

[0066] Figure 5 The gel permeation chromatography (GPC) spectra of the hole transport layer compounds prepared in Examples 1, 5 and 11 according to the present invention are shown, which are evaluated based on weight-average molecular weight (Mw). Detailed Implementation

[0067] The various embodiments of the present invention will be described in detail below.

[0068] Unless otherwise stated, all terms used herein (including technical and scientific terms) have the meaning commonly understood by one of ordinary skill in the art. It should also be understood that terms (e.g., those defined in common dictionaries) should be interpreted as having the meaning consistent with their meaning in the context of the specification and the relevant field, and should not be interpreted as having an idealized or overly formal meaning unless explicitly defined herein.

[0069] It should also be understood that, unless otherwise stated, the use of the terms "comprises" or "comprising" in this specification indicates the presence of the stated elements and / or components, but does not exclude the presence or addition of one or more other elements and / or components.

[0070] The hole transport layer compound represented by Formula 1 is prepared using a method for manufacturing a hole transport layer compound according to an embodiment of the present invention, and the method may include: polymerizing the hole transport layer compound by introducing raw materials and a catalyst into a vacuum transfer system; and mixing the hole transport layer compound with an ion exchange resin to remove reaction impurities.

[0071] [Formula 1]

[0072]

[0073] In Equation 1, R 1 R 2 and R 3 Each is independently hydrogen or C1 to C 10 alkyl.

[0074] The vacuum transfer system (hereinafter referred to as the "VT system") may include a main reactor (100) loaded with raw materials and catalyst, a sub-reactor (200) loaded with solvent, and a VT line (300) connecting the main reactor to the sub-reactor.

[0075] The main reactor (100) is a reactor that produces high molecular weight hole transport layer compounds by introducing raw materials and catalysts and using polymerization reactions.

[0076] The solvent is introduced into the sub-reactor (200) and then moved to the main reactor (100) so that the polymerization reaction can occur rapidly through the raw materials and catalyst in the solvent.

[0077] The VT line (300) can transport liquid compounds by utilizing the correlation between vacuum and temperature within a closed system, and may include an intermediate line (310) with an inlet, a main line (320) branching from the intermediate line and connected to the main reactor (100), and a sub-line (330) branching from the intermediate line and connected to the sub-reactor (200).

[0078] Additionally, the intermediate pipeline (310) may be equipped with an intermediate valve (311) to open or close the intermediate pipeline. For example, when the vacuum pipeline is connected to the inlet of the intermediate pipeline (310), opening the intermediate valve (311) allows the VT pipeline (300) and the reactors (100 and 200) connected to the VT pipeline (300) to be evacuated.

[0079] The main pipeline (320) may be equipped with a main valve (321) to open or close the main pipeline. Depending on whether the main valve is in the open or closed position, the main reactor (100) connected to the main pipeline may be connected to an intermediate pipeline (310), a sub-pipeline (330), or both the intermediate pipeline (310) and the sub-pipeline (330), or isolated from both the intermediate pipeline (310), the sub-pipeline (330), or both the intermediate pipeline (310) and the sub-pipeline (330).

[0080] Sub-line (330) may be equipped with sub-valve (331) to open or close the sub-line. Depending on whether the sub-valve is in the open or closed position, sub-reactor (200) connected to the sub-line may be connected to intermediate line (310), main line (320), or both intermediate line (310) and main line (320), or isolated from intermediate line (310), main line (320), or both intermediate line (310) and main line (320).

[0081] The polymerization of hole transport layer compounds can be carried out using a main reactor (100), a sub-reactor (200), and a VT pipeline (300).

[0082] Specifically, raw materials, catalysts, phosphine ligands, phase transfer catalysts, and an aqueous alkaline solution can be introduced into the main reactor (100) and mixed together. Here, the raw materials, catalysts, phosphine ligands, and phase transfer catalysts can be mixed in an aqueous solution of an inorganic salt. The main reactor (100) can be connected to a main pipeline (320) in preparation for the reaction. Alternatively, a solvent can be introduced into a sub-reactor (200), which is then connected to a sub-pipeline (330) in preparation for the reaction.

[0083] The sub-reactor (200) can be maintained at a low temperature. For example, a low-temperature bath can be provided on the sub-reactor (200) to maintain the sub-reactor at a temperature of about -200°C to 0°C.

[0084] With the intermediate valve (311), main valve (321), and sub-valve (331) closed, the vacuum line can be connected to the inlet of the intermediate line (310), and then all valves (intermediate valve (311), main valve (321), and sub-valve (331)) can be opened to evacuate the reactors (100 and 200) and the VT line (300). A manifold vacuum line can be used as the vacuum line here.

[0085] After evacuating the reactors (100 and 200) and VT line (300) while monitoring the vacuum level with a vacuum gauge, the intermediate valve (311) can be closed to isolate the main reactor (100) and the sub-reactor (200), thus forming a closed system. A cryogenic bath can be moved from the sub-reactor (200) to the main reactor (100) to raise the temperature of the sub-reactor (200) to room temperature (approximately 25°C) while cooling the main reactor (100). While maintaining the closed system under vacuum pressure, the solvent in the sub-reactor (200) can evaporate and move to the main reactor (100).

[0086] After solvent movement is complete, the sub-valve (331) can be closed while the intermediate valve (311) is opened. Subsequently, before polymerization, the main reactor (100) and VT line (300) are purged with nitrogen to switch to a nitrogen atmosphere. Specifically, after connecting the nitrogen manifold to the inlet of the intermediate line (310) with the main valve (321) and sub-valve (331) closed, the intermediate valve (311) can be opened, followed by the main valve (321) to switch the main reactor (100) and VT line (300) to a nitrogen atmosphere. Therefore, the VT system provides a strictly oxygen-free environment even when loading solid raw materials and catalysts, thereby maintaining catalytic activity and thus ensuring the reproducibility of hole transport layer compound synthesis. The synthesis of hole transport layer compounds can be carried out at a temperature of about 40°C to 120°C, preferably about 60°C to 100°C, more preferably about 70°C to 90°C for a duration of about 5 hours to 96 hours, preferably about 18 hours to 48 hours, and more preferably about 20 hours to 24 hours.

[0087] Reaction impurities can be removed from the remaining solution and precipitates (including polymerized hole transport layer compounds) in the main reactor (100). These impurities include residual byproducts, such as metal residues and salt compounds. Removal of these residual byproducts is desirable because they can impede the hole transport capability of the hole transport layer compound (PTAA). Most unreacted organic matter and low molecular weight polymers can be removed by repeating the precipitation process. However, while excess inorganic salts (e.g., NaOH, KOH, Na₂CO₃, K₂CO₃, and similar compounds) can generally be removed by repeated washing with a weak acid (e.g., 1% to 3% HCl), residual alkali metals (Na, K, Ca, and similar metals) may remain at levels of 500 ppm to 5,000 ppm in most hole transport layer compounds, and counter anions (Cl, Br, HSO₄, and similar substances) may also be present in amounts corresponding to the residual alkali metals. The presence of these residues not only impedes hole transport capability but can also significantly impair the stability and lifespan of the resulting device.

[0088] Alkali metal cations and their counter anions remaining in the hole transport layer compound can be removed using ion exchange resins. Specifically, reaction impurities can be removed by dissolving the polymerized hole transport layer compound in a solvent and mixing the resulting mixture with a cationic or anionic resin, followed by stirring and filtration. Here, the solvent used in the polymerization reaction can be used as the solvent. For example, alkali metal cations can be removed first by mixing the hole transport layer compound dissolved in the solvent with a cationic resin, followed by stirring and filtration, and then counter anions can be removed by mixing the filtered product with anionic resin, followed by stirring and filtration. Alternatively, counter anions can be removed first by mixing the hole transport layer compound dissolved in the solvent with anionic resin, followed by stirring and filtration, and then alkali metal cations can be removed by mixing the filtered product with a cationic resin, followed by stirring and filtration. Preferably, alkali metal cations are first removed by mixing a hole transport layer compound dissolved in a solvent with a cationic resin, followed by stirring and filtration, and then counter anions are removed by mixing the filtered product with an anionic resin, followed by stirring and filtration.

[0089] Here, the cation exchange resin may comprise a polymer containing sulfonic acid (R-SO3H) functional groups as a strongly acidic cation exchange resin or a polymer containing carboxylic acid (R-COOH) functional groups as a weakly acidic cation exchange resin, wherein the polymer may be prepared in, for example, bead form. Here, the adsorption affinity of the ion increases with increasing valence, and for ions of the same valence, the adsorption selectivity increases with increasing atomic number. Specifically, the adsorption selectivity of the cation exchange resin for cations follows the order: Ra 2+ Ba 2+ > Pb 2+ > Sr 2+ > Cu 2+ > Ca 2+ > Zn 2+ Fe 2+ > Mg 2+ Ni 2+ > Cd 2+ >Ti + Ag + > Cs + > Rb + K + > NH4 + Na + H + > Li + .

[0090] Examples of ion exchange reaction mechanisms of cation exchange resins are as follows:

[0091] 1) R-SO3H + NaCl R-SO3Na + HCl

[0092] 2) R-SO3H + NaOH R-SO3Na + H2O

[0093] 3) 2R-SO3Na + CaCl2 (R-SO3)2Ca + 2NaCl

[0094] 4) 2R-SO3H + Ca(HCO3)2 (R-SO3)2Ca + 2H2CO3

[0095] 5) R-COOH + NaCl R-COONa + HCl

[0096] 6) R-COOH + NaOH R-COONa + H2O

[0097] 7) 2R-COONa + CaCl2 (R-COO)2Ca + 2NaCl

[0098] 8) 2R-COOH + Ca(HCO3)2 (R-COO)2Ca + 2H2CO3

[0099] Anion exchange resins may contain quaternary ammonium salts (R'N). + R''3Cl - or R'N + R''3OH - Polymers with functional groups are used as strongly basic anion exchange resins, or contain tertiary ammonium salts (R'N). + R''2) Polymers with functional groups serve as weakly basic anion exchange resins, wherein the polymers can be prepared, for example, in bead form. Here, the adsorption selectivity of the anion exchange resin for anions follows the order: CrO 2- SeO4 2- SO4 2- > HAsO4 2- HSO4 - > I - NO3 - > Br - SeO3 2- HSO3 2- NO2- > Cl - HCO3 - > OH - > F - .

[0100] Examples of ion exchange reaction mechanisms of anion exchange resins are as follows. Mechanisms 1) to 4) involve strongly basic anion exchange resins formed from polymers containing quaternary ammonium salt functional groups, and mechanisms 5) to 8) involve weakly basic anion exchange resins formed from polymers containing tertiary ammonium salt functional groups.

[0101] 1) RN·OH + NaCl RN·Cl + NaOH

[0102] 2) RN·OH + HCl RN·Cl + H2O

[0103] 3) 2R-N·Cl + Na2SO4 (RN)₂SO₄ + 2NaCl

[0104] 4) RN·OH + H2SiO3 R-NHSiO3 + H2O

[0105] 5) R-NH·OH + NaCl R-NH·Cl + NaOH

[0106] 6) R-NH·OH + HCl R-NH·Cl + H2O

[0107] 7) 2R-NH·Cl + Na2SO4 (R-NH)₂SO₄ + 2NaCl

[0108] 8) R-NH·OH + H2SiO3 No reaction was observed.

[0109] The raw materials used to synthesize the hole transport layer compound represented by Formula 1 may include at least one of the compounds represented by Formulas 2 to 4. The hole transport layer compound represented by Formula 1 can be polymerized by polymerizing the compounds represented by Formulas 2 and 3, or by polymerizing the compound represented by Formula 4. The polymerization of the compounds of Formulas 2 and 3 corresponds to the AB type polymerization method, and the polymerization of only the compound represented by Formula 4 corresponds to the AA type polymerization method.

[0110] [Equation 2]

[0111]

[0112] [Formula 3]

[0113]

[0114] [Formula 4]

[0115]

[0116] In equations 1 to 3, R 1 R 2 and R 3 Each can be independently hydrogen or C1 to C2. 10 Alkyl group. In Formulas 2 and 4, X can be I, Br, Cl, or trifluoromethanesulfonate (OTf) independently.

[0117] In equations 3 and 4, R 4 Each can be independently hydrogen or C1 to C5 alkyl.

[0118] In equations 3 and 4, R 4 Each can be an independent C1 to C5 alkyl group, wherein the two Rs are C1 to C5 alkyl groups. 4 The groups can be linked together to form a cyclic alkyl group. Examples of compounds having this structure include 2,4,6-trimethyl-N,N-bis(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)aniline and similar compounds.

[0119] The polymerization of hole transport layer compounds can be carried out via Suzuki crosslinking coupling reaction, using various catalysts, phosphine ligands, bases and solvents under various heating conditions.

[0120] Catalysts may include, but are not limited to, palladium catalysts, such as palladium(II) acetate ([Pd(OAc)2]), tetrakis(triphenylphosphine)palladium(O) (Pd[(C6H5)3P]4), tris(dibenzylacetone)dipalladium(O) ([Pd2(dba)3]), and similar catalysts. These catalysts may be used alone or as mixtures thereof.

[0121] Phosphine ligands may include triphenylphosphine, tri-o-tolylphosphine, 1,1'-bis(diphenylphosphino)ferrocene (DPPF), 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP), and bis[(2-diphenylphosphino)phenyl]ether. Phosphine ligands include, but are not limited to, ether (DPEphos), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos), and the like. These phosphine ligands may be used alone or in mixtures thereof.

[0122] Bases can include inorganic salts, such as NaOH, KOH, LiOH, and Na+. t OBu、K t OBu、Li t OBu, Na2CO3, and K2CO3, preferably K2CO3 and Na2CO3. The alkali may be used in amounts from 3.0 equivalents to 12.0 equivalents, preferably from 6.0 equivalents to 10.0 equivalents, and more preferably from 7.0 equivalents to 9.0 equivalents.

[0123] Solvents may include, but are not limited to, N,N-dimethylformamide (DMF), N,N-dimethylformamide (DMAc), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), 1,4-dioxane, acetonitrile (ACN), tetrahydrofuran (THF), acetone, chloroform (CHCl3), dichloromethane (DCM), diethyl ether, toluene, xylene, hexane, methanol (MeOH), ethanol (EtOH), propanol derivatives (PrOH, isopropanol), butanol derivatives (n-butanol, tert-butanol), water, and similar solvents. These solvents may be used alone or in mixtures thereof.

[0124] Phase transfer catalysts may include, but are not limited to, tetrabutylammonium salts (TBAX, where X = Cl, Br, I), Aliquat 366, and similar phase transfer catalysts. These phase transfer catalysts may be used alone or as mixtures thereof.

[0125] Another aspect of the present invention relates to a hole transport layer compound manufactured by the method described above for manufacturing a hole transport layer compound. The hole transport layer compound may have a number-average molecular weight (Mn) of about 18 kDa or greater, preferably about 20 kDa to 100 kDa, and a weight-average molecular weight (Mw) of about 33 kDa or greater, preferably about 35 kDa or greater, more preferably about 35 kDa to 250 kDa. Furthermore, the hole transport layer compound may have a polydispersity index (PDI) of about 3.7 or less, preferably about 1.5 to 3.5, more preferably about 2.0 to 3.5.

[0126] Another aspect of the present invention relates to a hole transport layer made from the aforementioned hole transport layer compound.

[0127] Implementation of the invention

[0128] The invention will now be described in more detail with reference to some examples.

[0129] Example 1: Preparation of hole transport layer compounds (PTAA compounds)

[0130] In a 100 mL two-necked round-bottom flask, add 4.0 g (7.42 mmol) 2,4,6-trimethyl-N,N-bis(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)phenyl)aniline (TPA-Bpin), 3.3 g (7.42 mmol) N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline (TPA-Br), 0.25 g (0.74 mmol) tetrabutylammonium bromide (TBAB), 33.3 mg (0.149 mmol) Pd(OAc)2, and 304.4 mg (0.74 mmol) Pd(OAc)2. mmol) SPhos and degassed alkaline aqueous solution (KOH, 8 equivalents, 3M solution), and then the flask was connected to the main line of the vacuum transfer (VT) system.

[0131] Degassed toluene (15 mL) was introduced into another two-necked round-bottom flask, which was then connected to a subline of the VT system. The flask containing the solvent was cooled with liquid nitrogen, and then all valves were opened to evacuate the VT system until the pressure reached 10 Torr or less.

[0132] After all reactors and VT lines reach vacuum pressure, the intermediate valve is closed to isolate the two connected flasks, forming a closed system. Then, the liquid nitrogen bath beneath the solvent-containing flask is removed and moved to the flask used for the polymerization reaction. Here, as the temperature of the solvent flask rises, the solvent in the flask evaporates and completely migrates to the polymerization flask.

[0133] After the solvent transfer is complete, close the sub-valve on the solvent flask side and open the intermediate valve. Connect the nitrogen manifold to the inlet of the intermediate line to purify the reactor with a nitrogen atmosphere. Remove the liquid nitrogen bath below the polymerization reactor and replace it with an oil bath, then stir at approximately 90°C for about 3 hours.

[0134] After the polymerization process was completed, toluene (50 mL) was added to dissolve the reaction product, followed by washing three times with water (40 mL). The resulting organic layer was added dropwise to MeOH (500 mL) to precipitate a solid, then stirred at 70 °C for 2 hours and subsequently filtered at room temperature to obtain a solid PTAA compound (in the form of wet PTAA).

[0135] The obtained PTAA compound was dissolved in toluene (150 mL), and then a strong acidic cation exchange resin (20 mL) was added. The mixture was then stirred at room temperature for 10 hours and subsequently filtered to obtain a PTAA compound solution.

[0136] A strongly basic anion exchange resin (20 mL) was added to the obtained PTAA compound solution, which was then stirred at room temperature for 10 hours and subsequently filtered to obtain a PTAA compound solution. The PTAA compound solution was then distilled under reduced pressure to remove approximately one-third of the solvent.

[0137] The obtained PTAA compound solution was precipitated in methanol (200 mL), filtered, and dried to obtain the final PTAA compound (ivory-colored solid, yield = 80%). The properties of the obtained PTAA compound were then measured. 1 H nuclear magnetic resonance (NMR) 13 C NMR, Mn, Mw, and PDI. The PTAA compound has 41.7 kDa Mn, 107.0 kDa Mw, and 2.54 kDa PDI, and the PTAA compound... 1 H NMR and 13 The C NMR spectra are shown in Figure 3 and Figure 4 middle. 1 H NMR (400 MHz, CDCl3): δ 7.39 (d, J = 8.7 Hz, 4H), 7.02 (d, J = 8.7 Hz, 4H), 6.95 (s, 2H), 2.33 (s, 3H), 2.03 (s, 6H).

[0138] Examples 2 to 11: Preparation of Hole Transport Layer Compounds (PTAA Compounds)

[0139] Except for changes to the types of palladium catalyst, phosphine ligand, base and solvent, polymerization temperature and polymerization time as listed in Table 1, the PTAA compound was prepared in the same manner as in Example 1.

[0140] The number-average molecular weight (Mn), weight-average molecular weight (Mw), and polydispersity index (PDI) of each of the PTAA compounds prepared in Examples 2 to 11 were measured, and the results are shown in Table 1.

[0141] [Table 1]

[0142]

[0143] Although some examples have been described herein, the present invention is not limited to the above examples, and various modifications or changes can be made without departing from the technical spirit of the present invention, which will be obvious to those skilled in the art.

[0144] Explanation of icon numbers

[0145] 100: Main reactor

[0146] 200: Sub-reactor

[0147] 300: VT pipeline

[0148] 310: Intermediate Pipeline

[0149] 311: Intermediate valve

[0150] 320: Main Line

[0151] 321: Main valve

[0152] 330: Sub-pipeline

[0153] 331: Sub-valve

Claims

1. A method for manufacturing a hole transport layer compound represented by Formula 1, [Formula 1] in, R 1 R 2 and R 3 Each is independently hydrogen or C1 to C 10 alkyl, The method includes: polymerizing a hole transport layer compound by introducing raw materials and a catalyst into a vacuum transfer system; and mixing the polymerized hole transport layer compound with an ion exchange resin to remove reaction impurities.

2. The method according to claim 1, wherein the vacuum transfer system comprises: The main reactor, wherein the raw materials and the catalyst are introduced; Sub-reactor, in which solvent is introduced; as well as A vacuum transfer line connects the main reactor to the sub-reactor.

3. The method according to claim 2, wherein the vacuum transfer pipeline comprises: The intermediate pipeline has an inlet. The main pipeline branches off from the intermediate pipeline and connects to the main reactor; Sub-pipelines branch off from the intermediate pipeline and connect to the sub-reactor; An intermediate valve is installed on the intermediate pipeline; The main valve is located on the main pipeline; as well as Sub-valve, installed on the sub-pipeline.

4. The method of claim 3, wherein the step of polymerizing the hole transport layer compound comprises: The raw materials and the catalyst are introduced into the main reactor, and then the main reactor is connected to the main pipeline; The solvent is introduced into the sub-reactor, and then the sub-reactor is connected to the sub-pipeline; With the intermediate valve, the main valve, and the sub-valve closed, connect the vacuum line to the inlet of the intermediate line, and open the intermediate valve, the main valve, and the sub-valve to evacuate the main reactor and the vacuum transfer line, and then close the intermediate valve. Open the sub-valve to move the solvent to the main reactor; and When the solvent transfer is complete, the sub-valve is closed, the intermediate valve is opened, and the main reactor and the vacuum transfer line are purged with nitrogen gas, thereby initiating the polymerization reaction.

5. The method according to claim 4, wherein After the sub-reactor, in which the solvent is introduced, is connected to the sub-pipeline, the sub-reactor is cooled, and Before the solvent is moved to the main reactor, the temperature of the sub-reactor is raised to room temperature while the main reactor is cooled, so as to allow the solvent to evaporate in the sub-reactor and move to the main reactor.

6. The method of claim 1, wherein the polymerized hole transport layer compound is mixed with a cationic or anionic resin, followed by stirring and filtration to remove the reaction impurities.

7. The method of claim 6, wherein the reactive impurities are removed by: mixing the polymerized hole transport layer compound with the cationic resin and stirring and filtering the resulting mixture, subsequently mixing the filtered product with the anionic resin and stirring and filtering the resulting mixture, or The polymerized hole transport layer compound is mixed with the anion exchange resin, and the resulting mixture is stirred and filtered. The filtered product is then mixed with the cationic resin, and the resulting mixture is stirred and filtered.

8. The method according to claim 6, wherein The cationic resin comprises a polymer containing sulfonic acid functional groups or carboxylic acid functional groups, and The anion exchange resin comprises a polymer containing quaternary ammonium salt functional groups or tertiary ammonium salt functional groups.

9. The method of claim 1, wherein the hole transport layer compound represented by formula 1 is obtained by polymerization of compounds represented by formulas 2 and 3 or by polymerization of compounds represented by formula 4: [Equation 2] [Formula 3] [Formula 4] In equations 1 to 3, R 1 R 2 and R 3 Each is independently hydrogen or C1 to C 10 alkyl, In equations 2 and 4, X is independently I, Br, Cl, or OTf, and, In equations 3 and 4, R 4 Each is independently hydrogen or C1 to C5 alkyl, or each is independently C1 to C5 alkyl, with two Rs. 4 Groups are linked together to form cyclic alkyl groups.

10. The method according to claim 2, wherein the phosphine ligand, phase transfer catalyst and base are further introduced into the main reactor.

11. The method of claim 1, wherein the hole transport layer compound has a number-average molecular weight (Mn) of 18 kDa or greater, a weight-average molecular weight (Mw) of 33 kDa or greater than 33 kDa, and a polydispersity index (PDI) of 3.7 or less than 3.

7.

12. A hole transport layer compound, manufactured by the method for manufacturing a hole transport layer compound as described in claim 1.

13. A hole transport layer, made of the hole transport layer compound as claimed in claim 12.

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