KR102299609B1 - New polymer and organic electroluminescent device comprising the same - Google Patents

Abstract

The present invention relates to a novel polymer and a long-life organic light-emitting device comprising the same.

Description

New polymer and organic electroluminescent device comprising the same

The present invention relates to a novel polymer and an organic light emitting device including the same, wherein the polymer includes a first repeating unit in which a heteroaromatic ring having a specific structure is introduced into the main chain in a pendant form and a second repeating unit in which a crosslinking group is present. .

An organic light-emitting device (organic EL device) is an active light-emitting display device that emits light while electrons and holes are paired and then extinguished when electric charges are injected into an organic film formed between an electron injection electrode (cathode) and a hole injection electrode (anode). am. Not only can devices be formed on a flexible transparent substrate such as plastic, but it can also be driven at a lower voltage (10V or less) than a plasma display panel or inorganic EL display, and power consumption is reduced. It is relatively small and has the advantage of excellent color.

A typical organic light emitting device includes a substrate, an anode, a hole injection layer that receives holes from the anode, a hole transport layer that transports holes, a light emitting layer that emits light by combining holes and electrons, an electron transport layer that receives electrons from the cathode and transfers them to the light emitting layer, and a cathode. In some cases, the light emitting layer may be formed by doping a small amount of fluorescent or phosphorescent dye into the electron transport layer or hole transport layer without a separate light emitting layer. of polymers can be performed simultaneously. The organic material layers between the two electrodes are formed by vacuum deposition, spin coating, inkjet printing, roll coating, etc., and a separate electron injection layer is sometimes inserted for efficient injection of electrons from the cathode.

The material used for the organic material layer may be divided into a vacuum vapor deposition material and a solution coating material according to a manufacturing method of the organic material layer. The solution-applyable material should be miscible with a solvent to provide a composition that can be applied on a substrate, and the composition may be provided on a substrate or the like using a known solution application method such as inkjet printing, screen printing, or spin coating. .

The organic light emitting device can be classified into a low molecular type and a high molecular type according to the material of the organic material.

In the low-molecular-weight type, a thin film is produced by vacuum deposition using an organic material with a small molecular weight. The low-molecular-weight type has a well-known material property, so the technology improves quickly and the lifespan is relatively good. It is difficult to apply to a large-area process using

On the other hand, in the polymer type, a thin film is produced by a solution process such as spin coating or inkjet using an organic material having a high molecular weight, that is, a polymer. The polymer type has a slow technological improvement and a relatively short lifespan, but it is economical because it does not require an expensive vacuum device, has good mechanical strength, has a simple manufacturing process, and is advantageous for large area.

However, when OLED is manufactured using a solution process, interlayer mixing occurs in the process of stacking organic layers, or due to material purity problems and deterioration of other layer materials due to high temperature heat treatment (crosslinking reaction, etc.) It has lower characteristics than the deposition-type device, and in particular, has a disadvantage in that the lifespan is low.

Therefore, research on various solution process materials and processes is being actively conducted.

KR 10-2018-00763025 A

Accordingly, the present inventors have repeatedly studied materials suitable for solution processing in consideration of the problems of the prior art, and as a result of repeated research on materials suitable for solution processing, a solution processing material capable of improving lifespan and efficiency due to increased solvent resistance, including repeating units of a specific structure The present invention was completed to provide a polymer and an organic light emitting device using the same.

An object of the present invention is to provide a polymer having a novel structure.

Another object of the present invention is to provide an organic light emitting device using the polymer.

The present invention relates to a novel polymer and an organic light emitting device including the same, wherein the polymer comprises a first repeating unit in which a heteroaromatic ring having a specific structure is introduced into a main chain in a pendant form and a second repeating unit in which a crosslinking group exists. It relates to a polymer having a novel structure and an organic light emitting device including the same.

The present invention provides a polymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).

[Formula 1]

[Formula 2]

(In Formulas 1 and 2,

Ring A and Ring B are each independently a C6-C20 aromatic ring, and the ring A and B are selected from the group consisting of C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl and C3-C20 heteroaryl. may be further substituted with one or more;

R ¹ and R ² are each independently hydrogen, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl or C3-C20 heteroaryl;

at least one of X ¹ to X ^{4 is CR 11} and the others are CR ¹² or N;

R ¹¹ and R ¹² are each independently hydrogen, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl or C3-C20 heteroaryl;

Ar is C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl or C3-C20 heteroaryl;

L ¹ is a single bond, C1-C10 alkylene, -O-(C1-C10)alkylene-, -C(=O)- or -OC(=O)-;

R' is hydrogen or C1-C20 alkyl;

a is an integer from 0 to 2;

b is an integer of 1 or 2;

Said heteroaryl includes one or more heteroatoms selected from N, O and S.)

In addition, the present invention provides an organic light emitting device including the polymer.

The polymer according to the present invention is a first repeat in which a heteroaromatic ring having a specific structure, particularly 9H-indeno[2,1-b]pyridine, is introduced into the main chain in a pendant form. Due to the structural specificity including the unit and the second repeating unit in which the crosslinking group exists, the resistance to organic solvents is dramatically increased after thermal curing, so that the organic material layer can be formed by a solution process, so it is efficient to manufacture large-area and curved displays am.

In addition, when the polymer according to the present invention is employed as a light emitting layer in an organic material layer of an organic light emitting device, it has better current efficiency, light emitting efficiency and device lifespan than conventional materials, and exhibits appropriate color coordinates.

In addition, the polymer according to the present invention has improved solubility in organic solvents, and the resistance to organic solvents is dramatically increased after thermal curing, which causes problems in the solution process, and the solvent used for the upper film when forming the upper film on the already formed organic film. It is possible to solve the problem of dissolving the lower film or penetrating into the lower film to damage the lower film, so that the multi-layered OLED can be manufactured more efficiently through the solution process.

The novel polymer according to the present invention and an organic light emitting device using the same will be described in detail below, but unless otherwise defined in technical terms and scientific terms used at this time, those of ordinary skill in the art to which the present invention pertains will generally understand Descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention in the following description will be omitted.

In the present specification, the term "C _A -C _B " means "the number of carbon atoms is greater than or equal to A and equal to or less than B".

As used herein, the term "alkyl" and other substituents comprising an "alkyl" moiety include both straight-chain and comminuted forms. In addition, as for the substituents containing alkyl and other alkyl moieties according to the present invention, a short-chain substituent having 1 to 7 carbon atoms is preferred, but a long-chain substituent of 8 or more is also an aspect of the present invention.

As used herein, the term "aryl" refers to an organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, either single or fused, suitably containing 4 to 7, preferably 5 or 6 ring atoms in each ring. It includes a ring system, and includes a form in which a plurality of aryls are connected by a single bond. Specific examples include phenyl, naphthyl, biphenyl, terphenyl, anthryl, indenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, peryleneyl, chrysenyl, naphthacenyl, fluoranthenyl, etc. , but not limited thereto.

As used herein, the term "heteroaryl" includes 1 to 4 heteroatoms selected from B, N, O, S. P(=O), Si and P as aromatic ring skeleton atoms, and the remaining aromatic ring skeleton atoms are It refers to an aryl group that is carbon, and is a 5- to 6-membered monocyclic heteroaryl, and a polycyclic heteroaryl condensed with one or more benzene rings, and may be partially saturated. In addition, heteroaryl in the present invention includes a form in which one or more heteroaryls are connected by a single bond. Specific examples include furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, isoxazolyl, oxazolyl, triazinyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc. monocyclic heteroaryl of; Benzofuranyl, benzothiophenyl, isobenzofuranyl, benzoimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, quinolyl, iso polycyclic heteroaryl such as quinolyl; and the like.

As used herein, the term “cycloalkyl” refers to a fully saturated and partially unsaturated hydrocarbon ring of 3 to 9 carbon atoms, including aryl or heteroaryl fused thereto.

As used herein, the term “alkylene” refers to a divalent organic radical derived from an aliphatic hydrocarbon.

The present invention provides a polymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).

[Formula 1]

[Formula 2]

(In Formulas 1 and 2,

Ring A and Ring B are each independently a C6-C20 aromatic ring, and the ring A and B are selected from the group consisting of C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl and C3-C20 heteroaryl. may be further substituted with one or more;

R ¹ and R ² are each independently hydrogen, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl or C3-C20 heteroaryl;

at least one of X ¹ to X ^{4 is CR 11} and the others are CR ¹² or N;

R ¹¹ and R ¹² are each independently hydrogen, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl or C3-C20 heteroaryl;

Ar is C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl or C3-C20 heteroaryl;

L ¹ is a single bond, C1-C10 alkylene, -O-(C1-C10)alkylene-, -C(=O)- or -OC(=O)-;

R' is hydrogen or C1-C20 alkyl;

a is an integer from 0 to 2;

b is an integer of 1 or 2;

Said heteroaryl includes one or more heteroatoms selected from N, O and S.)

The polymer according to the present invention has a structure including a first repeating unit in which a heteroaromatic ring of a specific structure is introduced into the main chain in a pendant form and a second repeating unit in which a crosslinking group exists. Due to this structural specificity, intermolecular crosslinking due to thermosetting The bonding can significantly increase the resistance to organic solvents.

In particular, the polymer according to an embodiment of the present invention comprises a first repeating unit in which a heteroaromatic ring in which a 6-membered ring, a 5-membered ring, and a 6-membered ring are condensed in a pendant form to a C6-C20 aromatic ring, which is the main chain of the polymer, is bonded and C6 A polymer including a second repeating unit in which a crosslinking group including a carbon-carbon double bond is bonded to a -C20 aromatic ring, it is chemically stable and has a high electron density.

In addition, the polymer according to an embodiment of the present invention has excellent solubility in organic solvents, and resistance to organic solvents, for example, solvents such as toluene, etc. is increased due to intermolecular crosslinking due to thermal curing, so the solution process It is possible to fabricate a stacked structure, a large area, and a curved display device through the

In addition, the polymer according to an embodiment of the present invention does not form a by-product because the intermolecular cross-linking reaction is performed by a radical reaction by heat without the use of an initiator.

In one embodiment, ring A constituting the main chain of the polymer may be benzene, naphthalene, biphenyl or fluorene, and ring B may be benzene, naphthalene, biphenyl, binaphthyl or fluorene, and the Ring A and ring B may be further substituted with one or more selected from the group consisting of C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl and C3-C20 heteroaryl.

In Formula 1 according to an embodiment, X ¹ to X ⁴ are all CR ¹¹ , and R ¹¹ may be hydrogen, C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl, or C3-C20 heteroaryl. have. In this way, 9H-indeno[2,1-b]pyridine (9H-indeno[2,1-b]pyridine) is introduced into the polymer main chain in a pendant form, a first repeating unit and a second repeating unit having a crosslinking group Due to the structural specificity of including, the resistance to the organic solvent is remarkably increased after thermal curing, so that the organic material layer can be formed by a solution process, which may be more preferable.

In one embodiment, the first repeating unit may be a repeating unit represented by the following formula (3), and the second repeating unit may be a repeating unit represented by the following formula (4).

[Formula 3]

[Formula 4]

(In Formulas 3 and 4,

R ¹ and R ² are each independently C1-C10 alkyl, C6-C12 aryl or C3-C12 heteroaryl;

R is hydrogen, C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl or C3-C20 heteroaryl;

Ar is C6-C20 aryl or C3-C20 heteroaryl;

Ring B is benzene, naphthalene, biphenyl, binaphthyl or fluorene;

Y ¹ is a single bond or —O—;

m is an integer from 1 to 5.)

Specifically, in terms of improving solvent resistance after thermal crosslinking, the first repeating unit is a repeating unit represented by the following Chemical Formula 3-1, and the second repeating unit is a repeating unit selected from the following Chemical Formulas 4-1 to 4-3 It can be:

[Formula 3-1]

[Formula 4-1]

[Formula 4-2]

[Formula 4-3]

(In Formulas 3-1, 4-1, 4-2 and 4-3,

R ¹ and R ² are each independently C1-C10 alkyl or C6-C12 aryl;

Ar is C6-C12 aryl or C3-C12 heteroaryl;

p and q are each independently an integer from 1 to 5.)

In one embodiment, the polymer may be a copolymer comprising the first repeating unit represented by Chemical Formula 3-1 and the second repeating unit represented by Chemical Formula 4-1.

In one embodiment, the polymer may be a copolymer comprising the first repeating unit represented by Chemical Formula 3-1 and the second repeating unit represented by Chemical Formula 4-2.

In one embodiment, the polymer may be a copolymer comprising the first repeating unit represented by Chemical Formula 3-1 and the second repeating unit represented by Chemical Formula 4-3.

The polymer according to an embodiment may be used in an organic material layer of an organic light emitting device due to its structural specificity, and more specifically, may be used as a material for forming a light emitting layer in the organic material layer.

The polymer according to an embodiment may have a weight average molecular weight of 10,000 to 10,000,000 g/mol, preferably 100,000 to 1,000,000 g/mol, based on polystyrene, but is not limited thereto. The weight average molecular weight may be measured using (eg, gel permeation chromatography (GPC)).

The polymer according to an embodiment may be synthesized using a known organic synthesis method such as Suzuki coupling. The method for synthesizing the polymer can be easily recognized by those skilled in the art with reference to Examples to be described later.

In addition, the present invention provides an organic light emitting device including the polymer according to the embodiment.

An organic light emitting diode according to an embodiment includes a first electrode; a second electrode; and one or more organic material layers interposed between the first electrode and the second electrode. When the organic material layer of the organic light emitting device has a multilayer structure, it may have a structure in which, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and the like are stacked. However, the structure of the organic light emitting device is not limited thereto and may include a smaller number of organic material layers.

The organic material layer may include the polymer, and the polymer may include a light emitting layer.

The first electrode may be an anode layer, and is an electrode for injecting holes into the hole injection layer. Accordingly, the material for forming the anode layer is not limited as long as the properties are imparted to the anode layer. Specific examples of the material for forming the anode layer include metals such as vanadium, chromium, copper, zinc, gold, or alloys thereof, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO) and Metal oxides, such as ZnO:Al or SnO2:Sb combinations of metals and oxides, poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDT) , a conductive polymer such as polypyrrole and polyaniline, but is not limited thereto. In addition, the anode layer may be formed of only one type of the above-mentioned materials or a mixture of a plurality of materials, and a multilayer structure composed of a plurality of layers having the same composition or different compositions may be formed.

The organic material layer according to an embodiment may include a hole injection layer (HIL), a hole blocking layer (HBL), a hole transport layer (HTL), a light emitting layer, an electron transport layer (ETL), an electron injection layer (EIL), etc. may be omitted depending on

The hole injection layer (HIL) may be formed on the first electrode by using various methods such as vacuum deposition, spin coating, casting, Langmuir Blodgett (LB), etc., and may be used as a material of the hole injection layer CuPc (copper phthalocyanine), NPD (N,N'-dinaphthyl-N,N'-phenyl-(1,1'-biphenyl)-4,4'-diamine), m-MTDATA (4,4', 4"-tris(3-Methylphenylphenylamino)triphenylamine), 1-TNATA (4,4',4''-tris[1-naphthyl(phenyl)amino] triphenyl amine), 2-TNATA (4,4',4' Aromatic amines such as '-tris[2-naphthyl(phenyl)amino] triphenyl amine) and p-DPA-TDAB (1,3,5-tris[N-(4-diphenylaminophenyl)phenylamino] benzene) may be used. .

In addition, the hole transport layer (HTL) is formed by various methods such as vacuum deposition, spin coating, casting, LB (Langmuir Blodgett) method, etc. It can be formed using As a material for the usable hole transport layer, a commonly used material may be used, preferably NPB (N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine), NPD (N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine), TPD (N,N'-Bis(3-methylphenyl)-N, N'-diphenylbenzidine), TTB (N,N,N',N'-tetrakis(4-methylphenyl)-(1,1'-biphenyl)-4,4-diamine), TTP (N1,N4-diphenyl-N1 ,N4-dim-tolylbenzene-1,4-diamine), ETPD (N,N'-bis(4-methylphenyl)-N,N'-bis(4-ethylphenyl)-[1,1'-(3,3) '-dimethyl)biphenyl]-4,4'-diamine), VNPB (N4,N4'-di(naphthalen-1-yl)-N4,N4'-bis(4-vinylphenyl)biphenyl-4,4'-diamine ), ONPB (N4,N4'-bis(4-(6-((3-ethyloxetan-3-yl)methoxy)hexyl)phenyl)-N4,N4'-diphenylbiphenyl-4,4'-diamine), OTPD ( N4,N4'-bis(4-(6-((3-ethyloxetan-3-yl)methoxy)hexyl)phenyl)-N4,N4'-diphenylbiphenyl-4,4'-diamine) ; Polymer hole transport materials such as PVK (poly-N-vinylcarbazole), polyaniline, (phenylmenyl)polysilane, and poly(3,4-ethylenedioxythiophene)-poly(styrnesulfonate) (PEDOT:PSS), a polythiophene derivative, may be used. have.

The light emitting layer according to an embodiment may be formed on the hole transport layer using various methods such as a spin coating method, a casting method, and a Langmuir Blodgett (LB) method. The light emitting layer may include only the polymer according to an embodiment, or may include a known host, dopant, etc. in addition to the polymer. The film thickness of the said light emitting layer is not specifically limited.

The light emitting layer may be formed through a solution process and then manufactured through thermal crosslinking at 150 to 200° C., and the solution process may be selected from the group consisting of spin coating, inkjet coating, and nozzlejet coating. Since the interface of the light emitting layer is not dissolved in an organic solvent, specifically, a solvent such as toluene after thermal crosslinking, a light emitting device having a multilayer structure can be effectively manufactured without interlayer mixing.

The polymer according to an embodiment is dissolved in an organic solvent and exists in a solution state during device manufacturing, but is not soluble in an organic solvent after heat curing, that is, excellent resistance to organic solvents, so it is more suitable for a solution process, When applied as a light emitting layer of an organic light emitting device, luminous efficiency, color purity, and lifespan can be improved.

The light emitting layer can obtain a color of high luminance with higher efficiency by using a phosphorescent dopant together. In this case, the dopant used is not limited, and a known dopant may be selected and used as necessary. The phosphorescent dopant is a compound capable of emitting light from triplet excitons, and is not particularly limited as long as it emits light from triplet excitons, and includes one or more metals selected from the group consisting of Ir, Ru, Pd, Pt, Os and Re. It is preferable that it is a metal complex, and especially a porphyrin metal complex or an ortho metallized metal complex is preferable. As the porphyrin metal complex, a porphyrin platinum complex is preferable. Although there are various ligands for forming the ortho metallized metal complex of the phosphorescent dopant, preferred ligands include 2-phenylpyridine derivatives, 7,8-benzoquinoline derivatives, 2-(2-thienyl)pyridine derivatives, and 2-(1). -naphthyl) pyridine derivative, 2-phenylquinoline derivative, etc. are mentioned. These derivatives may have a substituent as needed. As an auxiliary ligand, it may further have a ligand other than the above ligands such as acetylacetonato and picric acid. Specific examples include bisthienylpyridine acetylacetonate Iridium, bis(benzothienylpyridine)acetylacetonate iridium {bis(benzothienylpyridine)acetylacetonate Iridium}, bis(2-phenylbenzothiazole)acetylacetonate Iridium {Bis(2-phenylbenzothiazole)acetylacetonate Iridium}, bis(1-phenylisoquinoline)iridium acetylacetonate {bis(1-phenylisoquinoline) Iridium acetylacetonate}, tris(1-phenylisoquinoline)iridium {tris(1-phenylisoquinoline) )Iridium}, tris(phenylpyridine)iridium {tris(phenylpyridine)Iridium}, tris(2-biphenylpyridine)iridium {tris(2-phenylpyridine)Iridium}, tris(3-biphenylpyridine)iridium {tris(3) -biphenylpyridine)Iridium}, tris(4-biphenylpyridine)iridium {tris(4-biphenylpyridine)Iridium}, tris[2-(p-tolyl)pyridine]iridium(III) {tris[2-(p-tolyl) pyridine]iridium(III)}, but is not limited thereto. The amount of the dopant included in the light emitting layer is not limited, but it is preferably included in the range of 2 to 20 parts by weight based on 100 parts by weight of the host material, and the content of the total dopant with respect to the total weight of the light emitting layer is in the range of 0.5 to 35% by weight. good.

In this case, in order to prevent the triplet excitons or holes from diffusing into the electron transport layer, a hole blocking layer (HBL) may be formed. In the case of forming the hole blocking layer by the vacuum deposition method and the spin coating method, the conditions vary depending on the compound used, but in general, it may be within the range of substantially the same conditions as the hole injection layer formation. A known hole blocking material can also be used, and examples thereof include oxadiazole derivatives, triazole derivatives, and phenanthroline derivatives. For example, the following BCP may be used as the hole blocking layer material.

The electron transport layer (ETL) can be formed on the light emitting layer or hole blocking layer using various methods such as vacuum deposition, spin coating, and casting, and is mainly composed of a material containing a chemical component that attracts electrons. For this, high electron mobility is required, and electrons are stably supplied to the light emitting layer through smooth electron transport. A usable material for the electron transport layer is a material commonly used, preferably

TSPO1 (diphenyl-4-triphenylsilylphenylphosphine oxide), TPBI (1,3,5-tris(N-phenylbenzimiazole-2-yl)benzene); Alq ₃ (Tris(8-hydroxyquinolinato)aluminum); BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline); PBD (2-(4-biphenyl)-5-(4-tert-butyl)-1,3,4-oxadizole), TAZ (3-(4-biphenyl)-4-phenyl-5-(4-tert- azole compounds such as butyl)-1,2,4-triazole), OXD-7 (1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene) ; phenylquinozaline; TmPyPB (3,3'-[5'-[3-(3-Pyridinyl)phenyl][1,1':3',1''-terphenyl]-3,3''-diyl]bispyridine) However, the present invention is not limited thereto.

An electron injection layer may be formed on the electron transport layer or the emission layer, and the electron injection layer may be deposited using LIF or lithium quinolate (Liq), but is not limited thereto.

The second electrode may be a negative electrode layer, and a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead or an alloy thereof, LiF/Al or LiO2/Al A metal having a low work function, such as a multi-layered material such as , may be used, preferably Al.

The organic light emitting diode according to the present invention overcomes the low-life characteristics of existing materials, and can secure high-performance light-emitting characteristics with high efficiency and long life in each color.

The organic light emitting device according to the present invention described above may be applied to a display device, and the display device may be a display device using a backlight unit, and the organic light emitting device may be used as a light source or a single light source of a backlight unit, etc. The display device may be an organic light emitting display (OLED), but is not limited thereto.

Hereinafter, for a detailed understanding of the present invention, the polymer according to the present invention, its manufacturing method, and the light emitting characteristics of the device will be described with reference to the representative compound of the present invention, and the following examples are provided for illustrative purposes of the present invention It is not intended to limit the scope of protection of

1. Measurement of Weight Average Molecular Weight

Measurements were made in 1,2,3-trichlorobenzene solvent at 135° C. at a rate of 1.0 mL/min using Freeslate Rapid GPC, and molecular weight was corrected using a PL polystyrene standard.

[Example 1] Preparation of polymer P1

Preparation of compound 1-a

Put 2-indanone (50 g, 378 mmol) and 3,5-dibromobenzaldehyde (119 g, 450 mmol) in a 3000 mL three-necked round-bottom flask, and then dissolved in ethanol (1500 mL), 0°C A 9M aqueous sodium hydroxide solution (500 mL) was slowly added thereto, and the mixture was stirred at room temperature for 3 hours. The resulting solid was separated by filtration under reduced pressure and washed with methanol to obtain compound 1-a as a yellow solid (130 g, yield 92%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 7.94 (t, 1H), 7.69 (t, 1H), 7.62 (d, 1H), 7.45 (d, 2H), 7.37 (t, 1H), 7.26 (m , 2H), 3.89 (d, 2H)

Preparation of compound 1-c

Add pyridine (1500 mL) to a 3000 mL three-necked round-bottom flask, and slowly add phenacyl bromide (150 g, 753 mmol) while stirring. After stirring at room temperature for 2 hours, the precipitated solid was separated by filtration under reduced pressure and washed with methanol. After filtration, the obtained solid (compound 1-b) (145 g, 521 mmol), compound 1-a (100 g, 264 mmol), and ammonium acetate (62 g, 804 mmol) were dissolved in methanol (1500 mL), It was refluxed for 12 hours. After cooling to room temperature, the precipitated solid was separated and filtered by filtration under reduced pressure, and washed with methanol to obtain compound 1-c as a yellow solid (47.5 g, yield 36%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 8.02 (m, 3H), 7.84 (t, 1H), 7.78 (d, 2H), 7.52 (t, 1H), 7.48 (m, 3H), 7.42 (m , 1H), 7.39 (m, 1H), 7.35 (d, 1H), 4.14 (s, 2H)

Preparation of compound 1-d

Put compound 1-c (45 g, 94.3 mmol), potassium t-butoxide (25.2 g, 226 mmol) and tetrahydrofuran (900 mL) in a 2000 mL 3-neck round-bottom flask, and when all dissolved at 0°C After stirring until , iomethane (38.4 g, 270 mmol) was slowly added and stirred at room temperature for 4 hours. Upon completion of the reaction, distilled water (1000 mL) and ethyl acetate (500 mL) were added for extraction, dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. After concentration, the obtained residue was separated and purified by silica gel column (hexane : ethyl acetate = 5 : 1) to obtain compound 1-d as a white solid (30 g, yield 62%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 8.02 (m, 3H), 7.84 (t, 1H), 7.79 (d, 2H), 7.53 (d, 2H), 7.44 (m, 4H), 7.36 (d , 1H), 1.78 (s, 6H)

Preparation of compound 1-e

Compound 1-d (30 g, 59.3 mmol), bis(pinacolato)diboron (33 g, 131 mmol), [1,1'-bis(diphenylphosphino)-ferrocene] in a 1000 mL 3-neck flask Palladium (II) dichloride dichloromethane complex (PdCl ₂ (dppf) _{2 .CH 2} Cl ₂ ) (1.93 g, 2.4 mmol), potassium acetate (23.2 g, 237 mmol) and 1,4-dioxane (500 mL) and stirred under reflux for 12 hours. After completion of the reaction, the temperature of the reactant was cooled to room temperature, distilled water (600 mL) and ethyl acetate (500 mL) were added to extract the mixture, dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. After concentration, the obtained residue was separated and purified by silica gel column (hexane:ethyl acetate = 5:1) to obtain compound 1-e as a white solid (23.5 g, yield 66%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 8.02 (m, 3H), 7.72 (d, 2H), 7.48 (d, 8H), 1.78 (d, 6H), 1.40 (m, 24H)

Preparation of compound Inter-1

In a 1000 mL 3-neck round-bottom flask, 2,7-dibromo-9H-fluorene (25 g, 78 mmol), 6-bromo-1-heptane (26.4 g, 147 mmol) and DMSO (200 mL) were added Then, potassium hydroxide (12.9 g, 231 mmol) was added, and the mixture was heated and stirred at 80° C. for 9 hours. After completion of the reaction, the temperature of the reactant was cooled to room temperature, distilled water (300 mL) and ethyl acetate (300 mL) were added to extract the mixture, dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. After concentration, the obtained residue was separated and purified by silica gel column (hexane: ethyl acetate = 20: 1) to obtain the compound Inter-1 as a white solid (18.8 g, yield 50%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 7.64 (d, 2H), 7.53 (d, 2H), 7.40 (d, 2H), 5.81-5.69 (m, 2H), 5.03 (d, 4H), 2.07 -1.95 (m, 6H), 1.48 (p, 4H), 1.40-1.29 (m, 6H)

Preparation of polymer P1

Compound 1-e (3 g), compound Inter-1 (2.58 g), bistriphenylphosphinepalladium dichloride (3.5 mg), trioctylmethylammonium chloride (Aliquat 336) in a 250 mL 3-neck round bottom flask under a nitrogen stream ) (0.9 g) and toluene (50 mL) were added, and refluxed for 15 hours while heating and stirring at 110°C. After the reaction, phenylboronic acid (550 mg) was added and refluxed for additional 6 hours. After the temperature of the reactant was cooled to room temperature, it was washed three times with distilled water (50 mL), washed twice with 2M hydrochloric acid (30 mL), and washed three times with distilled water (50 mL) again. After the obtained toluene layer was concentrated under reduced pressure, the obtained residue was extracted in a Soxhlet extractor for 20 hours, and the extracted toluene was concentrated. The solid obtained by Soxhlet extraction was dissolved in toluene and added dropwise to methanol (450 mL), stirred for 2 hours, and filtered under reduced pressure to obtain polymer P1 (0.93 g). The obtained polymer P1 had a weight average molecular weight of 1.05 × 10 ⁵ .

[Example 2] Preparation of polymer P2

Preparation of compound Inter-2

2,5-dibromohydroquinone (15 g, 56 mmol), 6-bromo-1-hexene (19.17 g, 117 mmol) and ethanol (200 mL) were placed in a 1000 mL three-necked round-bottom flask, Potassium hydroxide (9.42 g, 168 mmol) was added, and the mixture was heated and stirred at 80° C. for 9 hours. After completion of the reaction, the temperature of the reactant was cooled to room temperature, concentrated under reduced pressure to remove ethanol, distilled water (200 mL) and ethyl acetate (300 mL) were added to extract, dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. After concentration, the obtained residue was separated and purified by silica gel column (hexane: ethyl acetate = 50: 1) to obtain the compound Inter-2 as a white solid (10.9 g, yield 40%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 7.11 (s, 2H), 5.81-5.69 (m, 2H), 5.04 (d, 4H), 4.03 (t, 4H), 2.11-2.02 (m, 4H) , 1.81-1.72 (m, 4H), 1.56-1.46 (m, 4H)

Preparation of polymer P2

Compound 1-e (3 g), compound Inter-2 (2.16 g), bistriphenylphosphine palladium dichloride (3.4 mg), trioctylmethylammonium chloride (Aliquat 336) in a 250 mL 3-neck round bottom flask under a nitrogen stream ) (0.9 g) and toluene (50 mL) were added, and refluxed for 15 hours while heating and stirring at 110°C. After the reaction, phenylboronic acid (550 mg) was added and refluxed for additional 6 hours. After the temperature of the reactant was cooled to room temperature, it was washed three times with distilled water (50 mL), washed twice with 2M hydrochloric acid (30 mL), and washed three times with distilled water (50 mL) again. After the obtained toluene layer was concentrated under reduced pressure, the obtained residue was extracted in a Soxhlet extractor for 20 hours, and the extracted toluene was concentrated. The solid obtained by Soxhlet extraction was dissolved in toluene and added dropwise to methanol (450 mL), stirred for 2 hours, and then filtered under reduced pressure to obtain polymer P2 (1.03 g). The obtained polymer P2 had a weight average molecular weight of 1.1 × 10 ⁵ .

[Example 3] Preparation of polymer P3

Preparation of compound Inter-3

6,6-dibromo-1,1'-bi-2-naphthol (10 g, 22 mmol), 6-bromo-1-hexene (7.71 g, 47 mmol) and Dimethylformamide (100 mL) was added, and potassium carbonate (9.3 g, 68 mmol) was added thereto, followed by heating and stirring at 80° C. for 9 hours. After completion of the reaction, the temperature of the reactant was cooled to room temperature, distilled water (200 mL) and ethyl acetate (300 mL) were added to extract the mixture, dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. After concentration, the obtained residue was separated and purified by silica gel column (hexane: ethyl acetate = 50: 1) to obtain the compound Inter-3 as a white solid (6.1 g, yield 45%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 8.10-8.05 (m, 2H), 7.83 (d, 2H), 7.77-7.68 (m, 4H), 7.33 (d, 2H), 5.76-5.66 (m, 2H), 5.05 (t, 4H), 4.00 (t, 4H), 2.06 (q, 4H), 1.77-1.68 (m, 4H), 1.56-1.46 (m, 4H)

Preparation of polymer P3

Compound 1-e (3.5 g), compound Inter-3 (3.55 g), bistriphenylphosphinepalladium dichloride (4.2 mg), trioctylmethylammonium chloride (Aliquat 336) in a 250 mL 3-neck round bottom flask under a nitrogen stream ) (1.1 g) and toluene (60 mL) were added, and refluxed for 15 hours while heating and stirring at 110°C. After the reaction, phenylboronic acid (600 mg) was added and refluxed for an additional 6 hours. After the temperature of the reactant was cooled to room temperature, it was washed three times with distilled water (50 mL), washed twice with 2M hydrochloric acid (30 mL), and washed three times with distilled water (50 mL) again. After the obtained toluene layer was concentrated under reduced pressure, the obtained residue was extracted in a Soxhlet extractor for 20 hours, and the extracted toluene was concentrated. The solid obtained by Soxhlet extraction was dissolved in toluene and added dropwise to methanol (550 mL), stirred for 2 hours, and then filtered under reduced pressure to obtain polymer P3 (0.93 g). The obtained polymer P3 had a weight average molecular weight of 1.01 × 10 ⁵ .

As a comparative polymer, a polymer CP1 having the following structure (weight average molecular weight 2 × 10 ⁵ ) was used.

[Experimental Example 1] Evaluation of solvent resistance on a glass substrate

The glass substrate (25mm×25mm×0.7mm) was ultrasonically washed for 10 minutes in distilled water in which the detergent was dissolved, and washed twice with distilled water for 10 minutes. After cleaning with distilled water, the substrate was sequentially ultrasonically cleaned for 10 minutes using a solvent of isopropyl alcohol, acetone, and methanol, and dried.

A liquid composition was prepared by dissolving the polymers P1 to P3 of the present invention and the comparative polymer CP1 in toluene at 1% by weight, respectively.

Each of the prepared liquid compositions was applied on a glass substrate mounted on a spin coater, a first thin film was formed at 500 rpm for 15 seconds, and a second thin film was formed at 1000 rpm for 30 seconds. Then, the films on the glass substrate were baked at 180° C. for 30 minutes each using a hot plate in a glove box substituted with nitrogen, and then the films on the glass substrate were cooled to room temperature. After dipping the glass substrate on which the film was formed in isopropyl alcohol, toluene and chlorobenzene, respectively, the resistance to the solvent of the thin film was measured through UV measurement. The obtained results are shown in Table 1 below.

polymer Whether thermosetting menstruum isopropyl alcohol toluene chlorobenzene P1 before thermosetting partial dissolution record record After heat curing (180℃) 99% 89% 74% P2 before thermosetting partial dissolution record record After heat curing (180℃) 99% 92% 83% P3 before thermosetting partial dissolution record record After heat curing (180℃) 99% 85% 71% CP1 before thermosetting partial dissolution record record After heat curing (180℃) 97% 77% 69%

From the results of Table 1, the films produced by spin coating the polymers P1, P2 and P3 according to the present invention were all dissolved in toluene before thermal curing, but after thermal curing at 180 ° C. Due to the increase, it can be seen that the resistance to toluene is significantly increased to 85% or more, and the film hardly dissolves. Accordingly, the polymers according to the present invention have high thermal crosslinking properties.

On the other hand, in the case of comparative polymer CP1, the resistance to toluene was 77% despite heat curing at 180° C.

That is, the polymer according to the present invention has a crosslinking group at the same time as the first repeating unit in which a 9H-indeno[2,1-b]pyridine group exists in a pendant form on the polymer main chain. Due to the structural specificity including the existing second repeating unit, the resistance to a specific solvent is dramatically increased after thermal curing, which causes a problem in the solution process. When the upper film is formed on the already formed organic film, the solvent used for the upper film dissolves the lower film It can be confirmed that it is effective in the production of multi-layered OLEDs through the solution process because it can solve problems that can cause damage to the lower film by penetrating into the lower film or damaging the lower film.

[Example 4] Fabrication of an organic light emitting device using polymer P1 according to the present invention

A glass substrate with a size of 25 mm × 25 mm × 0.7 mm having an indium tin oxide (ITO) transparent electrode line with a thin film thickness of 1500 Å was ultrasonically cleaned in distilled water in which detergent was dissolved for 10 minutes, and 2 for 10 minutes using distilled water. Washed repeatedly. Using a solvent of isopropyl alcohol, acetone and methanol, the substrate was sequentially ultrasonically cleaned for 10 minutes and dried. After dry cleaning using oxygen/argon plasma, a glass substrate having a transparent electrode line was vacuum-adsorbed in a spin coater equipment to fabricate a device for solution processing.

A polythiophene derivative, PEDOT:PSS (poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate))(Aldrich), which is a conductive polymer, is mixed with isopropyl alcohol to cover the transparent electrode on the surface on which the transparent electrode line is formed. It was diluted, spin-coated at 2000 rpm for 1 minute, and dried on a hot plate at 200° C. for 10 minutes to form a hole injection layer.

Next, a liquid composition for forming a light emitting layer in which the polymer P1 prepared in Example 1 was dissolved in toluene at 1 wt % was spin-coated (1500 rpm) on the hole injection layer, and heat-treated at 180° C. for 30 minutes to form a light emitting layer did. After vacuum deposition of TPBi (1,3,5-tris(N-phenylbenzimiazole-2-yl)benzene) on the light emitting layer to form an electron transport layer, LiF and aluminum are sequentially deposited on the electron transport layer to inject electrons An organic light emitting device was manufactured by sequentially forming a layer and a second electrode.

[Example 5] Fabrication of an organic light emitting device using polymer P2 according to the present invention

An organic light emitting diode was manufactured in the same manner as in Example 4, except that polymer P2 was used instead of polymer P1 in Example 4.

[Example 6] Fabrication of an organic light emitting device using polymer P3 according to the present invention

An organic light emitting diode was manufactured in the same manner as in Example 4, except that polymer P3 was used instead of polymer P1 in Example 4.

[Comparative Example 1] Fabrication of organic light emitting device using comparative polymer CP1

An organic light emitting diode was manufactured in the same manner as in Example 4, except that Comparative Polymer CP1 (weight average molecular weight 2×10 ^{5 ) was used instead of Polymer P1 in Example 4.}

Table 2 shows the EL light emission results of the organic light emitting device fabricated. T50 refers to the time taken for the luminance of the light emitting device to become 50% of the initial luminance.

organic light emitting device Polymer for light emitting layer formation EL wavelength (nm) color coordinates (x, y) T50 ^* Example 4 P1 (Example 1) 460 0.135, 0.139 16 hours Example 5 P2 (Example 2) 465 0.137, 0.140 18 hours Example 6 P3 (Example 3) 450 0.133, 0.128 20 hours Comparative Example 1 CP1 450 0.133, 0.130 9 hours ^* Time to be 50% of initial luminance

A solution using a polymer (P1, P2, P3) according to the present invention in which a 9H-indeno[2,1-b]pyridine (9H-indeno[2,1-b]pyridine) group exists in a pendant form on the polymer main chain When the device was manufactured by the process, it was confirmed that the lifespan characteristics were improved by about 1.78 times or more compared to the device using the comparative polymer (CP1) in which a benzene ring was introduced in the form of a pendant to the polymer main chain.

The polymer according to the present invention has excellent resistance to organic solvents during crosslinking, and when employed as a light emitting layer in an organic material layer of an organic light emitting device, luminous efficiency, color purity, and particularly lifespan characteristics can be improved.

It can be seen that the organic light emitting device manufactured using the polymer according to the present invention exhibits the same level of EL wavelength and color coordinates as those of the comparative example, and the lifespan is remarkably improved.

Therefore, since the polymer according to the present invention has excellent thermal crosslinking properties due to its structural specificity, it can have improved lifespan characteristics when manufacturing an organic light emitting device by a solution process, and can also solve the problem of the solution process, so that the multilayer process through the solution process It is effective in producing large-area and curved displays.

Although the embodiments of the present invention have been described in detail as described above, those of ordinary skill in the art to which the present invention pertains, without departing from the spirit and scope of the present invention as defined in the appended claims The invention may be practiced with various modifications. Accordingly, modifications of future embodiments of the present invention will not depart from the technology of the present invention.

Claims (7)

A polymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).
[Formula 1]

[Formula 2]

(In Formulas 1 and 2,
Ring A and Ring B are each independently a C6-C20 aromatic ring, and the ring A and B are selected from the group consisting of C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl and C3-C20 heteroaryl. may be further substituted with one or more;
R ¹ and R ² are each independently hydrogen, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl or C3-C20 heteroaryl;
at least one of X ¹ to X ^{4 is CR 11} and the others are CR ¹² or N;
R ¹¹ and R ¹² are each independently hydrogen, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl or C3-C20 heteroaryl;
Ar is C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl or C3-C20 heteroaryl;
L ¹ is a single bond, C1-C10 alkylene, -O-(C1-C10)alkylene-, -C(=O)- or -OC(=O)-;
R' is hydrogen or C1-C20 alkyl;
a is an integer from 0 to 2;
b is an integer of 1 or 2;
Said heteroaryl includes one or more heteroatoms selected from N, O and S.) The method of claim 1,
ring A is benzene, naphthalene, biphenyl or fluorene; Ring B is benzene, naphthalene, biphenyl, binaphthyl or fluorene, polymer. The method of claim 1,
The first repeating unit is a repeating unit represented by the following formula (3), and the second repeating unit is a repeating unit represented by the following formula (4), a polymer.
[Formula 3]

[Formula 4]

(In Formulas 3 and 4,
R ¹ and R ² are each independently C1-C10 alkyl, C6-C12 aryl or C3-C12 heteroaryl;
R is hydrogen, C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl or C3-C20 heteroaryl;
Ar is C6-C20 aryl or C3-C20 heteroaryl;
Ring B is benzene, naphthalene, biphenyl, binaphthyl or fluorene;
Y ¹ is a single bond or —O—;
m is an integer from 1 to 5.) 4. The method of claim 3,
The first repeating unit is a repeating unit represented by the following Chemical Formula 3-1, and the second repeating unit is a repeating unit selected from the following Chemical Formulas 4-1 to 4-3, a polymer.
[Formula 3-1]

[Formula 4-1]

[Formula 4-2]

[Formula 4-3]

(In Formulas 3-1, 4-1, 4-2 and 4-3,
R ¹ and R ² are each independently C1-C10 alkyl or C6-C12 aryl;
Ar is C6-C12 aryl or C3-C12 heteroaryl;
p and q are each independently an integer from 1 to 5.) An organic light-emitting device comprising the polymer according to any one of claims 1 to 4. 6. The method of claim 5,
The organic light emitting device may include a first electrode; a second electrode; and at least one organic material layer interposed between the first electrode and the second electrode, wherein the organic material layer includes the polymer. 7. The method of claim 6,
The polymer is included in the light emitting layer, an organic light emitting device.