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

Abstract

The present invention relates to a method for preparing a hole transport layer compound and specifically to a preparation method whereby a poly(triarylamine)-based polymer having a high purity and high molecular weight can be obtained as a hole transport layer compound.

Description

Method for preparing high-purity and high-molecular-weight hole transport layer compounds

[0001] The present invention relates to a method for manufacturing a hole transport layer compound, and specifically, to a method for manufacturing a poly(triarylamine)-based polymer as a hole transport layer compound that can be obtained in high purity and high molecular weight.

[0002] Poly(triarylamine) (PTAA) is a representative hole transport material used in perovskite solar cells. Although various hole transport materials are used, poly(triarylamine) (PTAA) is considered the most suitable compound for large-area solar cell applications, capable of guaranteeing both the stability and efficiency of solar cell modules. However, while poly(triarylamine) can be manufactured and purified at the laboratory level, several problems arise at the mass production scale.

[0003] First, polytriarylamines (PTAAs) are generally prepared using the Suzuki polymerization reaction. The reaction conditions involve the use of a palladium catalyst, a phosphine ligand, and an excess of inorganic bases. While this is not a significant issue in general monomolecular synthesis, the presence of excess metal within compounds used as hole transport layers, such as PTAAs, limits their role as a hole transport layer. In laboratory-scale operations, purification is carried out over extended periods using Soxhlet extraction equipment; however, implementing Soxhlet equipment is impossible and reproducibility is poor in large-scale production. In particular, Soxhlet can be considered a heterogeneous purification system because the distilled organic solvents are sparingly soluble in PTAAs. In other words, during the precipitation process, metals become trapped or aggregate within the polymer, resulting in a high metal content.

[0004] Second, since PTAA is a polymer, it is of paramount importance to possess a high molecular weight and a narrow polydispersity index. To maintain uniform polymerization conditions, the activity of the palladium catalyst must be continuously maintained. Since the palladium catalyst oxidizes and loses activity when exposed to oxygen in the air, raw material input must be possible while sealed off from external air during the initial stages of polymerization. In particular, when solid raw materials are input through the reactor manhole, the palladium catalyst is inevitably exposed to the air, and in typical manufacturing environments, the range of exposure is highly irregular.

[0005] To address these issues, methods such as nitrogen purging and nitrogen bubbling are generally used to isolate reactants from the air. However, as the reaction scale increases, the amount of palladium catalyst exposed to the air increases during the process of introducing solid reactants into the reaction solvent and the reactor; consequently, it has been difficult to obtain consistent polymerization results even with extended nitrogen bubbling times. Therefore, a system is required that can replace the interior of the reactor with nitrogen even when solid reactants are introduced, separate from the nitrogen bubbling performed prior to polymerization.

[0006] The hole transport layer of perovskite solar cells is a key material determining cell efficiency and accounts for the largest portion of the raw materials. Therefore, the hole transport layer must faithfully fulfill its role of transporting holes generated in the absorption layer to the electrode, and it must not contain any impurities other than the added dopant. However, unless a separate treatment process is performed after the polymerization reaction, an excess amount of metal salt remains, interfering with the hole transport function of the dopant. Consequently, a metal purification process using a homogeneous purification system is absolutely necessary.

[0007] Furthermore, due to the characteristics of organic polymers, it is important to possess a narrow polydispersity index and high molecular weight to ensure consistent performance. This is because the hole transport layer material is positioned above the perovskite light-absorbing layer (nip structure), and the layer plays a role not only in transporting holes but also in protecting the light-absorbing layer. Since the protection of the light-absorbing layer is a critical function, the hole transport layer must be a material that is stable against high temperatures and moisture. Therefore, to produce PTAA compounds with a narrow polydispersity index and high molecular weight, a system is required that can replace the interior of the reactor with nitrogen even when solid reactants are introduced, in addition to nitrogen purging and bubbling before polymerization.

[0008] In one aspect of the present invention, a method for preparing a hole transport layer compound represented by the following chemical formula 1, wherein

[0009] [Chemical Formula 1]

[0010]

[0011] R in Chemical Formula 1 above 1 , R 2 and R 3 Each independently hydrogen or C1 to C 10 It is an alkyl of, and

[0012] The above manufacturing method can provide a method for manufacturing a hole transport layer compound, comprising introducing raw materials and a catalyst into a vacuum transfer system to polymerize the hole transport layer compound and mixing with an ion resin to remove reaction impurities.

[0013] Preferably, the vacuum transfer system is,

[0014] A main reactor into which the above raw materials and catalyst are introduced;

[0015] A sub-reactor into which a solvent is introduced; and

[0016] A method for manufacturing a hole transport layer compound can be provided, comprising a VT line connecting the main reactor and the sub-reactor.

[0017] Preferably, the VT line is,

[0018] Middle line with an entrance;

[0019] A main line branched from the above intermediate line and connected to the above main reactor;

[0020] A sub-line branched from the above intermediate line and connected to the above sub-reactor;

[0021] An intermediate valve provided on the above intermediate line;

[0022] A main valve provided on the main line above; and

[0023] A method for manufacturing a hole transport layer compound comprising a sub-valve provided on the above sub-line can be provided.

[0024] Preferably, the polymerization of the hole transport layer compound is,

[0025] After introducing the above raw materials and catalyst into the main reactor, the main reactor is connected to the above main line, and

[0026] After introducing the above solvent into the sub-reactor, the sub-reactor is connected to the above sub-line, and

[0027] With the above intermediate valve, main valve, and sub-valve closed, connect a vacuum line to the inlet provided in the intermediate line, then open the above intermediate valve, main valve, and sub-valve to create a vacuum in the main reactor and VT line, and then close the intermediate valve.

[0028] Open the above sub-valve to transfer the solvent to the main reactor, and

[0029] A method for manufacturing a hole transport layer compound can be provided, comprising closing the sub-valve and opening the intermediate valve after the movement of the above solvent is completed, purging the main reactor and VT line with nitrogen, and then performing a polymerization reaction.

[0030] Preferably, after the sub-reactor into which the solvent is introduced is connected to the sub-line, the sub-reactor is cooled, and

[0031] A method for preparing a hole transport layer compound can be provided, comprising raising the temperature of the sub-reactor to room temperature and cooling the main reactor before transferring the solvent, thereby allowing the solvent vaporized in the sub-reactor to be transferred to the main reactor.

[0032] Preferably, a method for preparing a hole transport layer compound can be provided, wherein the polymerized hole transport layer compound is mixed with a cation resin or anion resin, and then stirred and filtered to remove reaction impurities.

[0033] Preferably, the polymerized hole transport layer compound is mixed with a cation resin, stirred and filtered, and then mixed with an anion resin, stirred and filtered;

[0034] A method for manufacturing a hole transport layer compound can be provided, wherein the above-mentioned polymerized hole transport layer compound is mixed with an anion resin, stirred and filtered, and then mixed with a cation resin, stirred and filtered to remove reaction impurities.

[0035] Preferably, the cation resin is a polymer comprising a sulfonylic acid functional group or a carbonyl acid functional group, and

[0036] The above anion resin can provide a method for manufacturing a hole transport layer compound, wherein the anion resin is a polymer comprising a quaternary ammonium salt functional group or a tertiary ammonium salt functional group.

[0037] Preferably, the hole transport layer compound represented by the above chemical formula 1 is,

[0038] It is a polymer of a compound represented by the following chemical formulas 2 and 3, or a polymer of a compound represented by the following chemical formula 4, and

[0039] [Chemical Formula 2]

[0040]

[0041] [Chemical Formula 3]

[0042]

[0043] [Chemical Formula 4]

[0044]

[0045] R in the above chemical formulas 1 to 3 1 , R 2 and R 3 Each independently hydrogen or C1 to C 10 It is an alkyl of, and

[0046] In the above chemical formulas 2 and 4, X is independently I, Br, Cl, or OTf, and

[0047] R in the above chemical formulas 3 and 4 4 Each is independently hydrogen or a C1 to C5 alkyl,

[0048] R in the above chemical formulas 3 and 4 4 Each is independently a C1 to C5 alkyl, and two R groups 4 A method for preparing a hole transport layer compound can be provided, wherein the groups are connected to each other to form a ring-shaped alkyl group.

[0049] Preferably, a method for preparing a hole transport layer compound can be provided by additionally introducing a phosphine ligand, a phase transition catalyst, and a base into the main reactor.

[0050] Preferably, a method for preparing a hole transport layer compound can be provided, wherein the number average molecular weight (Mn) of the hole transport layer compound is 18 kDa or more, the weight average molecular weight (Mw) is 33 kDa or more, and the degree of polymerization (PDI) is 3.7 or less.

[0051] In another aspect of the present invention, a hole transport layer compound prepared by the method for preparing the hole transport layer compound can be provided.

[0052] In another aspect of the present invention, a hole transport layer prepared from the hole transport layer compound can be provided.

[0053] According to the method for manufacturing a hole transport layer compound of the present invention, a polytriarylamine (PTAA) compound of high purity can be produced by removing unreacted organic matter and metal salts on a mass production scale.

[0054] Through a uniform purification system, a consistent inert condition environment can be maintained when polymerizing polytriarylamine (PTAA) compounds.

[0055] In addition, uniform polymerization conditions can be maintained through a uniform purification system, thereby providing a polymerization condition system with high molecular weight and a narrow degree of polymerization (PDI).

[0056] The molecular weight of the polytriarylamine (PTAA) polymer can be increased, thereby enhancing the thermal stability and hydrophobicity of the polytriarylamine (PTAA) compound, and improving the high-temperature stability of the hole transport layer prepared therefrom and reducing its hygroscopicity.

[0057] In addition, the molecular weight of the polytriarylamine (PTAA) polymer can be increased, which enhances the intermolecular interactions (π-π stacking) of the polytriarylamine (PTAA) compound, thereby improving the electrical conductivity of the hole transport layer prepared therefrom and providing excellent charge transfer capability.

[0058] Even if the inside of the reactor is exposed to air for a long time when raw materials are fed, a vacuum transfer system can be provided that maintains inert conditions after removing as much oxygen as possible that has penetrated into the reactor.

[0059] FIG. 1 briefly illustrates a vacuum transfer system according to the present invention.

[0060] Figure 2 illustrates the VT line of a vacuum transfer system.

[0061] FIG. 3 is a hole transport layer compound of Example 1 according to the present invention. 1 This shows the H NMR results.

[0062] FIG. 4 is a hole transport layer compound of Example 1 according to the present invention. 13 This shows the C NMR results.

[0063] Figure 5 shows the results of GPC (gel permeation chromatography) based on weight-average molecular weight (Mw) for Examples 1, 5, and 11 according to the present invention.

[0064] The present invention will be described below.

[0065] All terms used in this specification (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0066] Furthermore, throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0067]

[0068] A method for manufacturing a hole transport layer compound according to one embodiment of the present invention may include introducing raw materials and a catalyst into a vacuum transfer system to polymerize the hole transport layer compound and mixing with an ion resin to remove reaction impurities.

[0069] [Chemical Formula 1]

[0070]

[0071] R in Chemical Formula 1 1, R 2 and R 3 Each independently hydrogen or C1 to C 10 It is an alkyl of

[0072] A vacuum transfer system (hereinafter referred to as a VT system) may include a main reactor (100) into which raw materials and a catalyst are introduced, a sub-reactor (200) into which a solvent is introduced, and a VT line (300) connecting the main reactor and the sub-reactor.

[0073] The main reactor (100) is a reactor in which a high molecular weight hole transport layer compound is produced through a polymerization reaction by introducing raw materials and a catalyst.

[0074] A solvent is introduced into the sub-reactor (200), and the introduced solvent is transferred to the main reactor (100) so that a polymerization reaction can occur rapidly through the raw materials and catalyst in the solvent.

[0075] The VT line (300) can transport liquid compounds using the correlation between vacuum and temperature within a closed system and may include an intermediate line (310) with an inlet, a main line (320) branched from the intermediate line and connected to a main reactor (100), and a sub-line (330) branched from the intermediate line and connected to a sub-reactor (200).

[0076] In addition, an intermediate valve (311) is provided on the intermediate line (310) so that the intermediate line can be opened and closed. For example, if a vacuum line is connected to an inlet provided on the intermediate line (310), the intermediate valve (311) can be opened to create a vacuum state for the VT line (300) and the reactors (100 and 200) connected thereto.

[0077] A main valve (321) is provided on the main line (320) so that the main line can be opened and closed, and depending on the opening and closing of the main valve, the main reactor (100) connected to the main line can be connected to or closed from the intermediate line (310), sub line (330), or the intermediate line (310) and sub line (330).

[0078] A sub valve (331) is provided on the sub line (330) so that the sub line can be opened and closed, and depending on the opening and closing of the sub valve, the sub reactor (200) connected to the sub line can be connected to or closed from the intermediate line (310), the main line (320), or the intermediate line (310) and the main line (320).

[0079] Polymerization of the hole transport layer compound can be carried out using a main reactor (100), a sub-reactor (200), and a VT line (300).

[0080] Specifically, raw materials, a catalyst, a phosphine ligand, a phase transition catalyst, and a base aqueous solution can be introduced into the main reactor (100) and mixed. At this time, the raw materials, the catalyst, the phosphine ligand, and the phase transition catalyst can be mixed in an inorganic salt aqueous solution. The main reactor (100) can be connected to the main line (320) to prepare for the reaction. Additionally, after introducing a solvent into the sub-reactor (200), the sub-reactor (200) can be connected to the sub-line (330) to prepare for the reaction.

[0081] The sub-reactor (200) can be made to a low temperature state. For example, a low temperature bath can be provided in the sub-reactor (200) to make the sub-reactor (200) about -200°C to 0°C.

[0082] With the intermediate valve (311), main valve (321), and sub-valve (331) closed, a vacuum line can be connected to the inlet provided in the intermediate line (310), and then all valves (intermediate valve, main valve, and sub-valve) can be opened to create a vacuum in the reactors (100 and 200) and the VT line (300). At this time, a manifold vacuum line can be used for the vacuum line.

[0083] While checking the vacuum level through a vacuum gauge, the reactors (100 and 200) and the VT line (300) can be made into a vacuum, and then the intermediate valve (311) can be closed to make the main reactor (100) and the sub-reactor (200) into a closed system. By transferring a low-temperature bath from the sub-reactor (200) to the main reactor (100), the temperature of the sub-reactor (200) can be raised to room temperature (about 25°C) and the main reactor (100) can be cooled. With the vacuum level of the closed system maintained, the solvent in the sub-reactor (200) can be vaporized and transferred to the main reactor (100).

[0084] Once the movement of the solvent is complete, the sub-valve (331) is closed and the intermediate valve (311) is opened. Then, the main reactor (100) and the VT line (300) can be purged with nitrogen to switch to a nitrogen atmosphere, and the polymerization reaction can proceed. First, the main valve (321) and the sub-valve (331) are closed, and with the manifold nitrogen connected to the inlet of the intermediate line (310), the intermediate valve (311) is opened and the main valve (321) is opened sequentially to switch the main reactor (100) and the VT line (300) to a nitrogen atmosphere. When using the VT system in this way, even if solid raw materials and catalysts are introduced, oxygen can be thoroughly blocked, so the activity of the catalyst can be continuously maintained and the hole transport layer compound can be polymerized reproducibly. Polymerization can be carried out at about 40°C to 120°C, preferably about 60°C to 100°C, more preferably about 70°C to 90°C, and the polymerization time can be carried out in the range of about 5 hours to 96 hours, preferably about 18 hours to 48 hours, more preferably about 20 hours to 24 hours.

[0085]

[0086] Reaction impurities can be removed from the solution and precipitate remaining in the main reactor (100), including the polymerized hole transport layer compound. Reaction impurities include metal residues and salt compounds as residual byproducts, and it is desirable to remove them because they can interfere with the hole transport role of the hole transport layer compound (PTAA). Unreacted organic matter and low molecular weight polymers can mostly be removed by repeating the precipitation process. However, excess inorganic salts (e.g., NaOH, KOH, Na2CO3, K2CO3, etc.) can generally be removed by washing several times with a weak acid (e.g., 1-3% HCl), but alkali metals (Na, K, Ca, etc.) may remain in most hole transport layer compounds at a level of 500 to 5,000 ppm, and paired anions (Cl, Br, HSO4, etc.) may also be present in proportion to the content of the residual alkali metals. As a result, this not only hinders the movement of hole transport but can ultimately have a significant impact on the stability and lifespan of the device.

[0087] Alkali metal cations and their counterparts remaining in the hole transport layer compound can be removed using an ion exchange resin. Specifically, the polymerized hole transport layer compound can be dissolved in a solvent, mixed with either a cation exchange resin or an anion exchange resin, and then stirred and filtered to remove reaction impurities. In this case, the solvent used during the polymerization reaction may be used. For example, the polymerized hole transport layer compound dissolved in the solvent can be mixed with a cation exchange resin, stirred, and filtered to remove alkali metal cations, and then mixed again with an anion exchange resin, stirred, and filtered to remove counterparts. Alternatively, the counterparts can be removed first by mixing with an anion exchange resin, stirring, and filtering, and then mixed with a cation exchange resin, stirred, and filtered to remove alkali metal cations. Preferably, the polymerized hole transport layer compound dissolved in the solvent can be mixed with a cation exchange resin, stirred, and filtered to remove alkali metal cations, and then mixed again with an anion exchange resin, stirred, and filtered to remove counterparts.

[0088] In this case, the cation resin may be a polymer containing a sulfonylic acid (R-SO3H) functional group as a strong acidic cation resin or a polymer containing a carbonyl acid (R-COOH) functional group as a weak acidic cation resin, and, for example, a bead type may be used. In this case, the selective adsorption of ions increases as the valence of the ion increases, and among ions of the same valence, selectivity increases as the atomic number increases. Specifically, the order of selectivity of the cation resin for cations is 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 + am.

[0089] Examples of ion exchange reaction mechanisms of cation resins are as follows.

[0090] 1) R-SO3H + NaCl ↔ R-SO3Na + HCl

[0091] 2) R-SO3H + NaOH ↔ R-SO3Na + H2O

[0092] 3) 2R-SO3Na + CaCl2↔ (R-SO3)2Ca + 2NaCl

[0093] 4) 2R-SO3H + Ca(HCO3)2↔ (R-SO3)2Ca + 2H2CO3

[0094] 5) R-COOH + NaCl ↔ R-COONa + HCl

[0095] 6) R-COOH + NaOH ↔ R-COONa + H2O

[0096] 7) 2R-COONa + CaCl2↔ (R-COO)2Ca + 2NaCl

[0097] 8) 2R-COOH + Ca(HCO3)2↔ (R-COO)2Ca + 2H2CO3

[0098]

[0099] The anion resin is a strongly basic anion resin and is a quaternary ammonium salt (R'N + R''3Cl - or R'N + R''3OH - ) as a polymer or weakly basic anionic resin containing a functional group, a tertiary ammonium salt (R'N + A polymer containing an R''2) functional group can be used, for example, a bead type can be used. In this case, the selectivity order of the anion resin for anions is CrO 2- SeO4 2-SO4 2- >HAsO4 2- HSO4 - I - NO3 - Br - SeO3 2- HSO3 2- NO2 - > Cl - HCO3 - OH - > F - am.

[0100] Examples of ion exchange reaction mechanisms of anion resins are as follows. Mechanisms 1) to 4) relate to strongly basic anion resins made of polymers containing quaternary ammonium salt functional groups, and mechanisms 5) to 8) relate to weakly basic anion resins made of 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↔ Reaction does not proceed

[0109]

[0110] A raw material capable of polymerizing a hole transport layer compound represented by Chemical Formula 1 may include one or more of the following compounds 2 to 4. The hole transport layer compound represented by Chemical Formula 1 can be prepared by polymerizing compounds represented by Chemical Formulas 2 and 3 below, or by polymerizing a compound represented by Chemical Formula 4 below. Polymerizing compounds represented by Chemical Formulas 2 and 3 is an AB-type polymerization method, and polymerizing a compound represented by Chemical Formula 4 alone is an AA-type polymerization method.

[0111] [Chemical Formula 2]

[0112]

[0113] [Chemical Formula 3]

[0114]

[0115] [Chemical Formula 4]

[0116]

[0117] R in Chemical Formulas 1 to 3 1 , R 2 and R 3 Each independently hydrogen or C1 to C 10 It can be an alkyl. Also, in formulas 2 and 4, X can each independently be I, Br, Cl, or OTf (triplate).

[0118] R in chemical formulas 3 and 4 4 Each can independently be hydrogen or a C1 to C5 alkyl.

[0119] Also, R in chemical formulas 3 and 4 4 Each is independently a C1 to C5 alkyl, wherein two R groups 4They can be connected to each other to form a ring-shaped alkyl group. Specific examples 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).

[0120] Polymerization of hole transport layer compounds is possible using the Suzuki cross-coupling reaction under various catalysts, phosphine ligands, bases, solvents, and heating conditions.

[0121] A palladium catalyst is used, for example, palladium (II) acetate ([Pd(OAc)2]), tetracyclophenylphosphine palladium (O) (Pd[(C6H5)3P]4), palladium divie ([Pd2(dba)3]), etc., may be used alone or as a mixture of these, but is not limited thereto.

[0122] Phosphine ligands may include triphenylphosphine, tri-O-tolylphosphine, 1,1-diphenylphosphinoferrocene (DPPF), 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP), bis[phenyl] ether (DPEPhos), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos), etc., used alone or as a mixture of combinations thereof, but are not limited thereto. no.

[0123] Inorganic salts can be used as bases, such as NaOH, KOH, LiOH, and Na₂O₃. t OBu, K t OBu, Li t OBu, Na2CO3, K2CO3, preferably K2CO3 and Na2CO3 may be used. The base may be used in an amount of 3.0 to 12.0 equivalents, preferably 6.0 to 10.0 equivalents, and more preferably 7.0 to 9.0 equivalents.

[0124] The solvent may be N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrolidone (NMP), dimethyl sulfoxide (DMSO), 1,4-dioxane (1,4-dioxane), acetonitrile (ACN), tetrahydrofuran (THF), acetone, chloroform (CHCl3), dichloromethane (DMC), diethyl ether, toluene, xylene, hexane, methanol (MeOH), ethanol (EtOH), propanol derivatives (PrOH, iso-PrOH), butanol derivatives (n-BuOH, tert-BuOH), water, etc., and may be used alone or as a mixture of these, but is not limited thereto.

[0125] Phase transition catalysts may include tetrabutylammonium salts (TBAX (X = Cl, Br, I)), Aliquat 366, etc., and may be used alone or as a mixture of these, but are not limited thereto.

[0126]

[0127] Another embodiment according to the present invention may include a hole transport layer compound prepared by a method for preparing a hole transport layer compound. The number average molecular weight (Mn) of the hole transport layer compound may be about 18 kDa or more, preferably about 20 kDa or more to 100 kDa or less, and the weight average molecular weight (Mw) may be about 33 kDa or more, preferably about 35 kDa or more, more preferably about 35 kDa or more to 250 kDa or less. In addition, the degree of polymerization of the hole transport layer compound may have a value in the range of about 3.7 or less, preferably about 1.5 to 3.5, more preferably about 2.0 to 3.5.

[0128] In addition, a hole transport layer can be manufactured using the manufactured hole transport layer compound.

[0129] The present invention will be described in detail below through examples.

[0130]

[0131] Example 1. Preparation of a hole transport layer compound (PTAA compound)

[0132] In a 100 mL two-neck round-bottom flask, TPA-Bpin (2,4,6-trimethyl-N,N-bis(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl-phenyl)aniline) 4.0 g (7.42 mmol), TPA-Br (N,N-bis(4-bromophenyl)-2,4,6-trimethylaniline) 3.3 g (7.42 mmol), TBAB (Tetrabutylammonium bromide) 0.25 g (0.74 mmol), Pd(OAc)2 (33.3 mg, 0.149 mmol), SPhos (304.4 mg, 0.74 mmol), and degassed basic aqueous solution (KOH, After adding 8 equivalents (3 M solution), it was connected to the main line of the vacuum transfer (VT) system.

[0133] Degassed toluene (15 mL) was added to another 2-neck round-bottom flask and connected to the sub-line of the VT system. The flask containing the solvent was cooled using liquid nitrogen, and then all valves were opened to create a vacuum until the pressure was about 10 torr or less.

[0134] Once the vacuum was maintained in all reactors and VT lines, the intermediate valve was closed to create a closed system between the two connected flasks. The liquid nitrogen bath supporting the flask containing the solvent was removed and transferred to the polymerization reaction flask. At this time, as the temperature of the solvent flask rose, the solvent evaporated and was completely transferred to the polymerization reaction flask.

[0135] Once the solvent transfer was complete, the intermediate valve was opened and the sub-valve on the solvent flask side was closed. Manifold nitrogen was connected to the inlet of the intermediate line to replace the inside of the reactor with a nitrogen atmosphere. The liquid nitrogen bath placed on the side of the polymerization reactor was removed and replaced with an oil bath, after which the mixture was stirred at approximately 90°C for about 3 hours.

[0136] When the polymerization was completed, toluene (50 mL) was added to dissolve it, and then it was washed three times with water (40 mL). The obtained organic layer was added dropwise to MeOH (500 mL) to precipitate it as a solid, stirred at 70 °C for 2 hours, and filtered at room temperature to obtain a PTAA solid compound (wet PTAA form).

[0137] The obtained PTAA compound was dissolved in toluene (150 mL), then a strong acidic cation resin (20 mL) was added, stirred at room temperature for 10 hours, and filtered to obtain a PTAA compound solution.

[0138] A strong basic anion resin (20 mL) was added to the obtained PTAA compound solution, stirred at room temperature for 10 hours, and filtered to obtain a PTAA compound solution, after which about 1 / 3 of the solvent was removed by vacuum distillation.

[0139] The obtained PTAA compound solution was precipitated in methanol (200 mL), filtered, and dried to obtain a PTAA compound (ivory solid form, yield = 80%). Regarding the obtained PTAA compound 1 H NMR, 13 C NMR, M n , M w and PDI (degree of polymerization) was measured. M n Silver is 41.7 kDa, M w is 107.0 kDa, PDI is 2.54, and 1 The 1H NMR is shown in Fig. 3, and 13 The C NMR is shown in Figure 4. 1 H NMR (400 MHz, CDCl3): δ7.39 (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).

[0140]

[0141] Examples 2 to 11. Preparation of hole transport layer compounds (PTAA compounds)

[0142] It was prepared in the same manner as Example 1, but with different palladium catalyst, phosphine ligand, base, solvent, polymerization temperature, and polymerization time as shown in Table 1 below.

[0143] The number average molecular weight, weight average molecular weight, and PDI of each example are shown in Table 1.

[0144]

[0145]

[0146] It is obvious to those skilled in the art that the present invention is not limited to the above embodiments and can be implemented with various modifications or variations within the scope of the technical essence of the present invention.

[0147]

[0148] [Explanation of the symbol]

[0149] 100: Main reactor

[0150] 200: Sub-reactor

[0151] 300: VT Line

[0152] 310: Middle line

[0153] 311: Intermediate valve

[0154] 320: Main Line

[0155] 321: Main valve

[0156] 330: Sub line

[0157] 331: Sub-valve

Claims

1. A method for preparing a hole transport layer compound represented by the following chemical formula 1, wherein [Chemical Formula 1] R in Chemical Formula 1 above 1 , R 2 and R 3 Each independently hydrogen or C1 to C 10 It is an alkyl of, and The above manufacturing method is a method for manufacturing a hole transport layer compound, comprising introducing raw materials and a catalyst into a vacuum transfer system to polymerize the hole transport layer compound and mixing with an ion resin to remove reaction impurities.

2. In Claim 1, The above vacuum transfer system is, A main reactor into which the above raw materials and catalyst are introduced; A sub-reactor into which a solvent is introduced; and A method for manufacturing a hole transport layer compound comprising a VT line connecting the main reactor and the sub-reactor.

3. In Claim 2, The above VT line is, Middle line with an entrance; A main line branched from the above intermediate line and connected to the above main reactor; A sub-line branched from the above intermediate line and connected to the above sub-reactor; An intermediate valve provided on the above intermediate line; A main valve provided on the main line above; and A method for manufacturing a hole transport layer compound comprising a sub-valve provided on the above sub-line.

4. In Claim 3, The polymerization of the above hole transport layer compound is, After introducing the above raw materials and catalyst into the main reactor, the main reactor is connected to the above main line, and After introducing the above solvent into the sub-reactor, the sub-reactor is connected to the above sub-line, and With the above intermediate valve, main valve, and sub-valve closed, connect a vacuum line to the inlet provided in the intermediate line, then open the above intermediate valve, main valve, and sub-valve to create a vacuum in the main reactor and VT line, and then close the intermediate valve. Open the above sub-valve to transfer the solvent to the main reactor, and A method for preparing a hole transport layer compound, comprising closing the sub-valve and opening the intermediate valve after the movement of the above solvent is completed, purging the main reactor and VT line with nitrogen, and then performing a polymerization reaction.

5. In Claim 4, After the sub-reactor into which the above solvent is introduced is connected to the sub-line, the sub-reactor is cooled, and A method for preparing a hole transport layer compound, comprising raising the temperature of the sub-reactor to room temperature and cooling the main reactor before transferring the solvent, thereby transferring the solvent vaporized in the sub-reactor to the main reactor.

6. In Claim 1, A method for preparing a hole transport layer compound, wherein the polymerized hole transport layer compound is mixed with a cation resin or anion resin, and then stirred and filtered to remove reaction impurities.

7. In Claim 6, The above-mentioned polymerized hole transport layer compound is mixed with a cation resin, stirred, and filtered, and then mixed with an anion resin, stirred, and filtered; A method for preparing a hole transport layer compound, wherein the above-mentioned polymerized hole transport layer compound is mixed with an anion resin, stirred and filtered, and then mixed with a cation resin, stirred and filtered to remove reaction impurities.

8. In Claim 6, The above cation resin is a polymer containing a sulfonylic acid functional group or a carbonyl acid functional group, and A method for preparing a hole transport layer compound, wherein the above-mentioned anion resin is a polymer comprising a quaternary ammonium salt functional group or a tertiary ammonium salt functional group.

9. In Claim 1, The hole transport layer compound represented by the above chemical formula 1 is, It is a polymer of a compound represented by the following chemical formulas 2 and 3, or a polymer of a compound represented by the following chemical formula 4, and [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 4] R in the above chemical formulas 1 to 3 1 , R 2 and R 3 Each independently hydrogen or C1 to C 10 It is an alkyl of, and In the above chemical formulas 2 and 4, X is independently I, Br, Cl, or OTf, and R in the above chemical formulas 3 and 4 4 Each is independently hydrogen or a C1 to C5 alkyl, R in the above chemical formulas 3 and 4 4 Each is independently a C1 to C5 alkyl, and two R groups 4 A method for preparing a hole transport layer compound in which the groups are connected to each other to form a cyclic alkyl group.

10. In Claim 2, A method for preparing a hole transport layer compound, wherein a phosphine ligand, a phase transition catalyst, and a base are additionally introduced into the main reactor.

11. In Claim 1, A method for preparing a hole transport layer compound, wherein the number average molecular weight (Mn) of the hole transport layer compound is 18 kDa or more, the weight average molecular weight (Mw) is 33 kDa or more, and the degree of polymerization (PDI) is 3.7 or less.

12. A hole transport layer compound prepared by the method for preparing a hole transport layer compound according to Claim 1.

13. A hole transport layer prepared from a hole transport layer compound according to claim 12.

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