KR101400472B1 - Organic electroluminescent polymer containing novel blue dopants and organic electroluminescent devices manufactured using the same - Google Patents

Abstract

The present invention relates to an organic electroluminescent polymer containing a novel structural unit and an electroluminescent device using the electroluminescent polymer. More particularly, the present invention relates to a dopant which absorbs high energy generated from the main chain and emits light with high efficiency And to an electroluminescent device using the electroluminescent polymer. The electroluminescent polymer according to the present invention can be used as a host material such as green, red and white light having high solubility, high thermal stability, high glass transition temperature, excellent film formability and high quantum efficiency.

Emission Polymer, Light Emitting Device, Blue Emission, Quantum Efficiency, Dopant

Description

TECHNICAL FIELD The present invention relates to an organic electroluminescent polymer including a novel blue dopant and an organic electroluminescent device using the same.

1 is a cross-sectional view showing the structure of a general organic electroluminescent device manufactured from a substrate / an anode / a hole transporting layer / a light emitting layer / an electron transporting layer / a cathode.

FIG. 2 is a schematic view showing synthesis reactions of monomers for electroluminescent polymers represented by M1, M2 and M3 of the present invention.

Fig. 3 is a schematic view showing the synthesis reaction of the monomer for electroluminescence polymer represented by M4 of the present invention.

4 is a view showing the outline of synthesis reaction of the monomer for electroluminescence polymer represented by M5 of the present invention.

Fig. 5 is a schematic view showing the synthesis reaction of the monomer for electroluminescence polymer represented by M6 of the present invention.

FIG. 6 is a graph showing the luminous efficiency according to the luminance of a device manufactured using the electroluminescent polymer according to Example 1 of the present invention. FIG.

7 is a graph showing a current density according to a voltage of a device manufactured using the electroluminescent polymer according to Example 1 of the present invention.

FIG. 8 is a graph showing the luminous efficiency according to the luminance of a device manufactured using the electroluminescent polymer produced according to Example 2 of the present invention. FIG.

9 is a graph showing a current density according to a voltage of a device manufactured using an electroluminescent polymer manufactured according to Example 2 of the present invention.

10 is a graph showing luminous efficiency according to luminance of a device manufactured using the electroluminescent polymer according to Example 3 of the present invention.

11 is a graph showing a current density according to a voltage of a device fabricated using an electroluminescent polymer manufactured according to Example 3 of the present invention.

Description of the Related Art

11: substrate 12: anode

13: hole transport layer 14: light emitting layer

15: electron transport layer 16: cathode

The present invention relates to an electroluminescent device containing a specific structural unit and an electroluminescence device (EL device) using the electroluminescent polymer. More particularly, the present invention relates to an electroluminescence device The 9-aryl-fluorene-9-yl group which can be minimized contains a specific structural unit which stabilizes a chromophore, and an electroluminescent device using the electroluminescent polymer.

Recently, the rapid growth of optical communication and multimedia has accelerated the development into a highly information-oriented society. Accordingly, an optoelectronic device that uses a photon to be converted into an electron or an electron to be converted into a photon is becoming a nucleus of the modern information electronics industry. Such a semiconductor optoelectronic device can be roughly classified into an electroluminescent element, a light receiving element, and an element in which they are combined.

Electroluminescence display, which is a self-luminous type, has a high response speed and self-emission type, so it does not need a backlight and has excellent brightness. Has attracted attention as a display device. Such electroluminescent devices are classified into inorganic and organic light emitting devices according to materials for forming light emitting layers.

Electroluminescence (EL) is a phenomenon in which electrons and holes are transferred from an anode and a cathode to each other when an electric field is applied to an organic material, and the generated energy is released into light. The electroluminescence phenomenon of such an organic material was reported by Pope et al. In 1963 and it was reported by Tang et al. In Eastmann Kodak in 1987 that alumina-quinone A light emitting device having a multi-layered structure having a quantum efficiency of 1% and a luminance of 1000 cd / m < 2 > at 10 V or less has been reported as a device fabricated with a π-conjugated dye. They have a simple synthesis route, which facilitates the synthesis of various types of materials and has the advantage of being able to perform color tuning. However, since the processability and the thermal stability are low and the voltage is applied, joule heat is generated in the light emitting layer, and the device is broken due to the rearrangement of the molecules, which causes problems in luminous efficiency and lifetime of the device. Organic electroluminescent device having an organic electroluminescent device is being replaced.

In this regard, FIG. 1 shows the structure of a general organic electroluminescent device fabricated from a substrate / anode / hole transport layer / light emitting layer / electron transport layer / cathode. Referring to FIG. 1, an anode 12 is formed on a substrate 11. A hole transport layer 13, a light emitting layer 14, an electron transport layer 15, and a cathode 16 are sequentially formed on the anode 12. Here, the hole transporting layer 13, the light emitting layer 14 and the electron transporting layer 15 are organic thin films made of an organic compound. The driving principle of the organic EL device having the above structure is as follows:

When a voltage is applied between the anode 12 and the cathode 16, holes injected from the anode 12 are transferred to the light emitting layer 14 via the hole transport layer 13. On the other hand, electrons are injected from the cathode 16 through the electron transporting layer 15 into the light emitting layer 14, and the carriers recombine in the light emitting layer 14 region to generate excitons. This exciton changes from the excited state to the ground state, and the fluorescent molecules of the light emitting layer emit light, thereby forming an image. The organic electroluminescent device driven by the above-described principle is classified into a polymer organic electroluminescent device and a low molecular organic electroluminescent device depending on the molecular weight of the organic film forming material.

Generally, when a low molecular weight is used in forming an organic film, a low molecular weight can be purified to a low level, and almost no impurities can be removed. However, there is a problem that inkjet printing or spin coating is not possible and heat resistance is poor, which deteriorates or re-crystallizes due to driving heat generated when the device is driven. On the other hand, when a polymer is used for forming an organic film, the energy level is separated by the conduction band and the electroconductivity due to the superimposition of the? -Electron wave function in the main chain of the polymer, and by the band gap energy corresponding to the energy difference The semiconducting properties of the polymer are determined and full color can be realized. Such a polymer is referred to as a? -Electron conjugated polymer.

An electroluminescent device using poly (p-phenylenevinylene) (hereinafter referred to as PPV), a conjugated double bond polymer, was developed by Professor RH Friend of Cambridge University in England for the first time in 1990 And organic polymers have been actively researched. The polymer is superior in heat resistance to low molecular weight, and ink-jet printing and spin coating are possible, which facilitates enlargement of the display device. Polyphenylene vinylene (PPV) derivatives, polythiophene (Pth) derivatives, and the like, which can improve workability and express various colors by introducing various suitable substituents, have been reported. However, with materials such as polyphenylenevinylene derivatives and polythiophene derivatives, it is possible to obtain high-efficiency red and green light-emitting polymer materials among the three primary colors of light, red, green and blue. However, it's difficult. Polyphenylene derivatives and polyfluorene derivatives have also been reported as blue light emitting polymer materials. Although polyphenylene has high oxidation stability and thermal stability, it has low luminous efficiency and low solubility.

With respect to the above polyfluorene derivatives, the prior art is as follows:

U.S. Patent No. 6,255,449 discloses 9-substituted-2,7-dihalofluorene compounds, and oligomers and polymers thereof, suitable as light emitting materials such as light emitting layers or carrier transport layers of light emitting diodes.

U.S. Patent Nos. 6,309,763 and 6,605,373 disclose electroluminescent copolymers containing fluorine groups and amine groups in the repeating units. According to the above-mentioned U.S. Patent No. 6,309,763, such a copolymer is useful as a light emitting layer or a hole transporting layer of an electroluminescence device.

U.S. Patent No. 6,630,566 discloses a polymer containing N, P, S, As or Se useful as a light emitting polymer, specifically, a polymer containing repeating units of triarylamine. U.S. Patent No. 6,887,973 discloses an anion There is disclosed a electroluminescent polymer containing a fluorene or phenylene repeating unit and a triarylamine unit such that the transferring material and the cation transferring material are present in one molecule and the first and second band gaps of different properties are present. Japanese Patent Application Laid-Open No. 2003-00199203 discloses an arylamine derivative having a fluorene skeleton.

As described above, researches using polyfluorene derivatives as blue light emitting polymers have been actively carried out. However, minimization of interactions between excitons generated in one molecule and excitons of adjacent molecules, injection and transport of holes and electrons , Improvement of efficiency, improvement of color purity and lifetime.

Accordingly, the present invention has been extensively studied in order to solve the above-mentioned problems, and as a result, it has been found that the color purity and the color purity, which are disadvantages of conventional polyfluorene (PFs) An electroluminescent polymer containing a new special structural unit introducing a specific structural unit which significantly improves the luminous efficiency and an electroluminescent device using the electroluminescent polymer have been found.

Accordingly, an object of the present invention is to provide an organic electroluminescent polymer capable of emitting blue, green, red and white light with high efficiency by minimizing intermolecular interaction and facilitating energy transfer.

Another object of the present invention is to provide an electroluminescent device manufactured using the electroluminescent polymer.

In order to achieve the above object, the organic electroluminescent polymer according to the present invention is an organic electroluminescent polymer comprising 9-aryl-fluoren-9-yl groups introduced into an organic electroluminescent polymer represented by any one of the following general formulas It is a light emitting polymer:

Wherein A is an aryl group which is the same or different and is substituted or unsubstituted with at least one substituent selected from the group consisting of straight or branched chain alkyl and alkoxy groups having 1 to 20 carbon atoms; An aryl group substituted with at least one substituent selected from the group consisting of a straight chain or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si ; Substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si, An aryl group having 2 to 4 carbon atoms and a heterocyclic ring;

Ar is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms;

R is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms;

Ar ₁ is an arylamine group substituted or unsubstituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms;

Ar ₂ is selected from the group consisting of C6 to C60 substituted or unsubstituted aromatic compounds, C2 to C60 substituted or unsubstituted heteroaromatic compounds and combinations thereof;

x is an integer of 1 to 10,000, y is an integer of 0 to 10,000, z is an integer of 4 to 100,000, x / y is 1/19 or more, and (x + y) : Having a ratio of 80;

x1 is an integer of 1 to 10,000, y1 is an integer of 0 to 10,000, z1 is an integer of 4 to 100,000, x1 / y1 is 1/19 or more, (x1 + y1): z1 is 5:95 to 20 : 80;

(k + 1) / m is 1/19 or more, and (k + 1 + m) is an integer of 1 to 10,000, m is an integer of 0 to 10,000, n is an integer of 8 to 100,000, : n has a ratio of 5:95 to 20:80.

The polymers represented by Formula 1, Formula 2 or Formula 3 have a weight average molecular weight of 800 to 4,000,000 and a molecular weight distribution of 1 to 10.

According to another aspect of the present invention, there is provided an electroluminescent device including at least one layer including the organic electroluminescent polymer between an anode and a cathode, wherein the layer is a hole transport layer or a light emitting layer.

Hereinafter, the present invention will be described in more detail.

As described above, the present invention relates to an organic electroluminescent polymer containing a specific structural unit functioning as a dopant which absorbs high energy generated from the main chain and emits light with high efficiency, and an electroluminescent device using the same will be. The electroluminescent polymer according to the present invention introduces special structural units with high solubility, high thermal stability, high glass transition temperature, good film formability and remarkably improved luminous efficiency.

The organic electroluminescent polymer according to the present invention is a light emitting polymer having excellent thermal stability, light stability, solubility, film formability, excellent hole injecting / delivering property, excellent color purity and high luminous efficiency, Since the 9-diary encapsulates the chromophore, the intermolecular excimer and aggregation are suppressed to the utmost, intramolecular or intermolecular energy transfer is easy, and the substituted and largely substituted fluorenyl groups can also be used for the rotation and vibration mode Is suppressed to greatly reduce nonradiative decay, so that it exhibits excellent color purity and high efficiency.

The electroluminescent polymer comprising a specific structural unit according to the present invention is represented by any one of the following Chemical Formulas 1 to 3:

[Chemical Formula 1]

(2)

(3)

Wherein A is an aryl group which is the same or different and is substituted or unsubstituted with at least one substituent selected from the group consisting of straight or branched chain alkyl groups and alkoxy groups having 1 to 20 carbon atoms; An aryl group substituted with at least one substituent selected from the group consisting of a straight chain or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si ; A straight or branched alkyl group having 1 to 20 carbon atoms and at least one hetero atom selected from the group consisting of F, S, N, O, P and Si, and an alkoxy group, An aryl group having a heterocycle of 4;

Ar is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms;

R is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms;

Ar ₁ is an arylamine group substituted or unsubstituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms;

Ar ₂ is selected from the group consisting of C6 to C60 substituted or unsubstituted aromatic compounds, C2 to C60 substituted or unsubstituted heteroaromatic compounds and combinations thereof;

x is an integer of 1 to 10,000, y is an integer of 0 to 10,000, z is an integer of 4 to 100,000, x / y is 1/19 or more, and (x + y) : Having a ratio of 80;

x1 is an integer of 1 to 10,000, y1 is an integer of 0 to 10,000, z1 is an integer of 4 to 100,000, x1 / y1 is 1/19 or more, (x1 + y1): z1 is 5:95 to 20 : 80;

(k + 1) / m is 1/19 or more, and (k + 1 + m) is an integer of 1 to 10,000, m is an integer of 0 to 10,000, n is an integer of 8 to 100,000, : n has a ratio of 5:95 to 20:80.

The polymers represented by formula (1), (2) or (3) have a weight average molecular weight of 800 to 4,000,000 and a molecular weight distribution of 1 to 10.

Preferably, A in the formulas (1) and (2) are the same or different from each other and can be selected from the following compounds:

On the other hand, representative examples of the aryl group having a heterocyclic ring are as follows, and can be preferably selected therefrom:

In the above formulas, R 1 and R 2 are the same or different and selected from the group consisting of hydrogen, straight or branched chain alkyl and alkoxy groups having 1 to 20 carbon atoms, and preferably selected from the following compounds.

In the above formula (1), Ar is selected from the group consisting of an aryl group substituted or unsubstituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group, Can be selected;

In Formula 1, R is hydrogen, or may be substituted with at least one substituent selected from the group consisting of a straight chain or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group. In this case, the substituent is preferably selected from the following compounds .

On the other hand, Ar ₁ can be selected from the following compounds:

On the other hand, Ar < ₂ >

(I) C6 to C60 substituted or unsubstituted arylene groups;

(Ii) a C2-C60 substituted or unsubstituted heterocyclic arylene group in which at least one hetero atom selected from the group consisting of N, S, O, P and Si is included in the aromatic ring;

(Iii) C6 to C60 substituted or unsubstituted arylene vinylene groups; And

(Iv) a combination of these,

Here, Ar ₂ represents a linear or branched alkyl or alkoxy group having 1 to 20 carbon atoms; An aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; Cyano group (-CN); Or a silyl group.

More specifically,

(I) when Ar ₂ is a phenylene group or a fluorenyl group in the C6-C60 substituted or unsubstituted arylene group, representative examples of such compounds are selected from the following:

(Ⅱ) if a substituted or non-heterocyclic ring is optionally substituted arylene group of said Ar ₂ is C2 ~ C60, typical examples of such compounds are as follows, and can be selected therefrom:

(Iii) when Ar ₂ is a C6 to C60 substituted or unsubstituted arylene vinylene group, representative examples of such compounds are as follows, and may be selected therefrom.

One of the methods for producing the organic electroluminescence polymer of the present invention is as follows. That is, monomers are prepared through an alkylation reaction, a bromination reaction, a Grignard reaction, a Wittig reaction or the like, and finally, an organic electroluminescence polymer is produced through a CC coupling reaction such as a Yamamoto coupling reaction or a Suzuki coupling reaction . The number average molecular weight of the obtained polymer is 800 to 4,000,000, and the molecular weight distribution is 1 to 10.

In the organic electroluminescent polymer according to the present invention, the bandgap of the chromophore portion having the special structure is the lowest, and this portion leads to the luminescence. In this case, the 9-aryl-fluorene-9-yl group is substituted for the chromophore terminal, which is a light emitting portion, to have excellent thermal stability, oxidation stability and solubility, high glass transition temperature, And can be applied as a host for blue, green, red and white luminescence which exhibits high emission efficiency by suppressing the vibration mode as much as possible.

According to the present invention, the organic electroluminescent polymer is used as a material for forming a light emitting layer or a hole transporting layer located between a pair of electrodes in an electroluminescent device. The organic electroluminescent device of the present invention may further include a hole transport layer and an electron transport layer as well as the most general device structure of the anode / light emitting layer / cathode.

1 is a cross-sectional view illustrating a structure of a general organic electroluminescent device composed of a substrate / an anode / a hole transporting layer / a light emitting layer / an electron transporting layer / a cathode and an organic electroluminescent device using the organic electroluminescent polymer according to the present invention, . ≪ / RTI >

First, a material for the anode 12 electrode is coated on the substrate 11.

Here, the substrate 11 used in a typical organic electroluminescent device is preferably a glass substrate or a transparent plastic substrate having excellent transparency, surface smoothness, ease of handling, and waterproofness.

As the material for the anode 12 electrode, indium tin oxide (ITO), tin oxide (SnO ₂ ), zinc oxide (ZnO), or the like, which is transparent and excellent in conductivity, may be used.

Next, the hole transport layer 13 may be formed by vacuum deposition or sputtering on the anode 11, and the light emitting layer 14 may be formed by a solution coating method such as spin coating, inkjet printing, or the like. Further, the electron transport layer 15 is formed on the light-emitting layer 14 before the cathode 16 is formed. At this time, the thickness of the light emitting layer 14 is preferably 5 nm to 1 μm, preferably 10 to 500 nm, and the thickness of the hole transporting layer and the electron transporting layer is preferably 10 to 10,000 Å.

According to the present invention, a typical electron transport layer forming material is used for the electron transport layer (15).

The hole transport layer 13 and the electron transport layer 15 efficiently transport carriers to the light emitting polymer, thereby enhancing the probability of luminescence coupling in the light emitting polymer. The hole transport layer 13 and the electron transport layer 15 which can be used in the present invention are not particularly limited but are preferably poly (styrene sulfonic acid) (PSS) PEDOT: PSS, N, N'-bis (3-methylphenyl) -N, N-diphenyl- [1,1'- biphenyl] -4, 4'-diamine (TPD) is preferable. Examples of the electron transport layer material include aluminum trihydroxyquinoline (Alq3), 1,3,4-oxadiazole derivative PBD (2- (4-biphenylyl) -5- phenyl-1,3,4-oxadiazole, quinoxaline derivatives such as TPQ (1,3,4-tris [(3-penyl-6-trifluoromethyl) quinoxaline-2-yl] benzene and triazole derivatives.

Meanwhile, when the organic electroluminescent polymer according to the present invention is formed by a solution coating method, it is blended with polymers having conjugated double bonds such as fluorene-based polymers, polyphenylene vinylene-based, and polyparaphenylene-based polymers In some cases, the binder resins may be mixed and used. Examples of the binder resins include polyvinylcarbazole, polycarbonate, polyester, polyarylate, polystyrene, acrylic polymer, methacrylic polymer, polybutyral, polyvinyl acetal, diallyl phthalate polymer, phenol resin, epoxy resin, Silicone resin, polysulfone resin or urea resin, and these resins may be used individually or in combination.

Alternatively, a hole-blocking layer such as lithium fluoride (LiF) may be further formed by vacuum deposition or the like to restrict a hole transporting rate in the light emitting layer 14, The probability can be increased.

Finally, a material for the cathode (16) electrode is coated on the electron transport layer (15).

As the metal for forming the cathode, lithium, magnesium, calcium, barium, aluminum, and aluminum: Li having a small work function are used.

The organic electroluminescent device according to the present invention may be manufactured in the order as described above, that is, in the order of anode / hole transporting layer / light emitting layer / electron transporting layer / cathode, It may be manufactured in order.

In addition, the organic electroluminescent polymer according to the present invention can be used not only for a polymer organic electroluminescent device but also for a photoconversion material in a photodiode or a semiconductor material organic solar cell in a polymer TFT (Thin Film Transistor).

As described above, the organic electroluminescence polymer according to the present invention has a structure in which the fluorenyl group, which is a large substituent at both ends of the chromophore, is introduced, thereby randomizing the arrangement between the main chain and the substituent by the substituent and suppressing the intermolecular excimer / RTI > and / or < RTI ID = 0.0 > excimer < / RTI > formation is inhibited. In addition, not only intramolecular or intermolecular energy transfer from a chromophore of a short wavelength substituent or main chain to a chromophore having a structural unit according to the present invention is possible, but also a rotation and vibration mode is suppressed by a substituted large fluorenyl group, It has a great advantage as a blue light emitting unit having excellent heat stability, light stability, solubility, film formability and high quantum efficiency, high efficiency and excellent color purity. Accordingly, the organic electroluminescent polymer of the present invention and the organic electroluminescent device using the same exhibit excellent color purity, brightness, and high luminescence efficiency.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto. On the other hand, the compounds referred to as M1 to M6 below are monomers for producing the electroluminescent polymer of the present invention, and are represented by the following structural formulas, respectively. The following specific monomers are intended to illustrate the invention and should not be construed as limiting the invention thereto.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto.

Manufacturing example  1: 9- (9,9- Dihexyl fluorene Yl) -2,7- Dibromofluorene -9-ol) (Compound (1)) Synthesis

3.3 g (137 mmol) of Mg was added to a 500 mL three-necked flask at room temperature, and 47.1 g (114 mmol) of 9,9-dihexyl-2-bromofluorene was dissolved in 200 mL of THF, . After the temperature of the reactor was lowered to -40 캜 or lower, 30 g (91 mmol) of 2,7-dibromofluorenone was added under a nitrogen stream, the temperature was gradually raised to room temperature, and the mixture was stirred for 10 hours. The reaction was poured into water, extracted with diethyl ether and the solvent was removed on a rotary evaporator. The residue was purified by column chromatography to obtain 45 g (67 mmol, 73%) of 9- (9,9-dihexylfluorene-2-yl) -2,7-dibromofluorene- 1)).

Manufacturing example  2: 1,2- Di (2-methyl) butyloxybenzene (Compound (2))

20 g (91 mmol) of the compound catechol and 107 g (436 mmol) of 2-methylbutyl p-toluenesulfonate were dissolved in 200 mL of DMSO, and then 53 g of potassium tertiary butoxide 473 mmol) was slowly added thereto, and the reaction was allowed to proceed at 70 DEG C for 12 hours. The reaction mixture was poured into 500 mL of water and extracted with methylene chloride. The solvent was removed by rotary evaporation and the product was separated by column chromatography using a mixed solvent of hexane and ethyl acetate to obtain 1,2-di (2 -Methyl) butyloxybenzene (compound (2)) (37 g, 148 mmol, 81%).

Manufacturing example  3: Monomer M1 Synthesis of

52.5 g (78 mmol) of the compound (1) obtained in Preparation Example 1 and 23.3 g (93 mmol) of the compound (2) obtained in Preparation Example 2 were dissolved in 1000 mL of dichloromethane in a 2 L round- The temperature was lowered to 0 ° C, and while stirring, 7.5 g (78 mmol) of methanesulfonic acid was dissolved in 100 mL of dichloromethane, and the mixture was stirred for 2 hours. The reaction was poured into water, extracted with diethyl ether, and the solvent was removed on a rotary evaporator. (9,9-dihexylfluorene-2-yl) -9- (3,4-di (2-methyl) butyloxyphenyl) fluo- 58.8 g (65 mmol, 83%) of the orange (M1) was obtained.

Manufacturing example  4: 9- (9,9- Dihexyl fluorene Yl) -9- (3,4- Di (2-methyl) butyloxyphenyl ) Fluorene -2,7- Of diboric acid (compound (3))  synthesis

58.8 g (65 mmol) of monomer M1 was added to a 250-mL round-bottomed flask at room temperature and dissolved in 60 mL of THF. The mixture was cooled to -70 ° C and 2 equivalents of 2.5M n-butyllithium was slowly added thereto. After reacting at a low temperature of 4 ° C, 4 equivalents of triethyl borate was added at the same temperature and stirred for 12 hours. The reaction mixture was poured into 3N-HCl aqueous solution, stirred for 4 hours, extracted with diethyl ether, and the solvent was removed with a rotary evaporator. The solidified material was repeatedly washed with toluene and dried to obtain 9,9-di (9 41.2 g (76%) of 9-dihydroxy-phenyl) fluorene-2-yl-9- (3,4- ).

Manufacturing example  5: Monomer M2 Synthesis of

54.3 g (65 mmol) of the compound (3) obtained in Preparation Example 4, 3 equivalents of ethylene glycol and 50 mL of anhydrous toluene were placed in a 100 mL round-bottomed flask, and a deanstark apparatus was installed. (9,9-dihexyl) fluorene-2-yl-9- (3,4-di (2-methyl) butyloxyphenyl) To obtain 50.2 g (57 mmol, 87%) of 7-bisboronic glycol ester (M2).

Manufacturing example  6: Monomer M3 Synthesis of

43.7 g (65 mmol) of the compound (1) and 200 g of 9,9-dihexylfluorene were dissolved in 1000 mL of dichloromethane in a 2 L round-bottomed flask at room temperature, and while the temperature was lowered to 0 ° C, 10 mL of methanesulfonic acid In 100 mL of dichloromethane was slowly poured into the flask and stirred for 2 hours. The reaction was poured into water, extracted with diethyl ether, and the solvent was removed on a rotary evaporator. Separation by column chromatography gave 37.3 g (38 mmol, 58%) of 9,9-di (9,9-dihexylfluorene-2-yl) -2,7-dibromofluorene (M3) .

Manufacturing example  7: Monomer M4 Synthesis of

At room temperature, 2.25 g (2.436 mmol) of tri (dibenzylideneacetone) dipalladium (Pd ₂ (dba) ₃ ), 1,1'-bis (diphenylphosphino) ferrocene g (3.654 mmol) of triphenylphosphine and 200 mL of toluene. The mixture was stirred for 30 minutes in a nitrogen stream, and then 25.85 g (81.2 mmol) of 4,4'-dibromo-biphenyl and 20 g 20.9 g (211.13 mmol) of sodium-tert-butoxide are added and reacted at 90 ° C for 4 hours. 20.9 g (211.13 mmol) of sodium-tert-butoxide was again added and the reaction was refluxed for 24 hours at an oil bath temperature of 130 < 0 > C. The temperature of the reaction was lowered to room temperature, 300 mL of distilled water was poured, and 400 mL of ethyl acetate was added to extract the solution. The organic solvent was removed using a rotary evaporator, and 15 g (21.13 mmol, 26%) of monomer M4 was prepared by separating by column chromatography using a mixed solvent of ethyl acetate and normal hexane.

Manufacturing example  8: 9- (9,9- Dihexyl fluorene Yl) -2- Bromofluorene -9-ol (Compound (4))

3.3 g (137 mmol) of Mg was added to a 500 mL three-necked flask at room temperature, and 47.1 g (114 mmol) of 9,9-dihexyl-2-bromofluorene was dissolved in 200 mL of THF, . After the temperature of the reaction vessel was lowered to -40 캜 or lower, 30 g (91 mmol) of 2-bromofluorenone was added under a nitrogen stream, the temperature was slowly raised to room temperature, and the mixture was stirred for 10 hours. The reaction was poured into water, extracted with diethyl ether and the solvent was removed on a rotary evaporator. (43 mg, 80%) of 9- (9,9-dihexylfluorene-2-yl) -2-bromofluorene-9-ol (compound (4)) was isolated by column chromatography. ≪ / RTI >

Manufacturing example  9: Synthesis of compound (5)

46.3 g (78 mmol) of the compound (4) obtained in Preparation Example 8 and 36.8 g (150 mmol) of triphenylamine were dissolved in 1000 mL of dichloromethane in a 2 L round-bottomed flask, the temperature was lowered to 0 캜, While 7.5 g (78 mmol) of methanesulfonic acid was dissolved in 100 mL of dichloromethane, and the mixture was stirred for 2 hours. The reaction was poured into water, extracted with diethyl ether, and the solvent was removed on a rotary evaporator. The product was separated by column chromatography to obtain 52.5 g (64 mmol, 82%) of the compound (5).

Manufacturing example  10: Synthesis of compound (6)

12 mL of DMF was added to a 100 mL three-necked flask, and the temperature was lowered to 0 ° C. in an ice bath. Then, 2.2 g (14.4 mmol) of POCl ₃ was gradually introduced. After stirring for 3 h at 0 [deg.] C, 8.0 g (9.6 mmol) of compound (5) was added. The reaction was stirred at 80 < 0 > C for 12 h, then poured into ice water and stirred for 30 min. The mixture was extracted with diethyl ether, neutralized with NaOH, and the solvent was removed by rotary evaporation. The product was separated by column chromatography to obtain 3 g (5.4 mmol, 56%) of compound (6).

Manufacturing example  11: Monomer M5 Synthesis of

After 5 g (5.9 mmol) of the compound (6) was dissolved in 50 mL of THF and allowed to stand in a nitrogen stream for 30 minutes, 1.32 g (2.9 mmol) of the compound (7) was slowly injected using a syringe , And the mixture was stirred at 80 占 폚 for 3 hours. The reaction was poured into water and stirred for 30 min, then extracted with diethyl ether and the solvent was removed on a rotary evaporator. The residue was separated by column chromatography to obtain 3.37 g (1.8 mmol, 62%) of a monomer M5.

Manufacturing example  12: Monomer M6 Synthesis of

10 g (16.8 mmol) of the compound (4) and 1.77 g (7 mmol) of perylene were dissolved in 150 mL of 1,2-dichlorobenzene in a 2 L round-bottomed flask at room temperature, , A solution of 1.62 g (16.8 mmol) of methanesulfonic acid in 10 mL of 1,2-dichlorobenzene was slowly injected, followed by stirring for 2 hours. The reaction was poured into water, extracted with dichloromethane and the solvent was removed on a rotary evaporator. The residue was separated by column chromatography to obtain 3.5 g (2.5 mmol, 36%) of monomer M6.

Example  1 to Example  3: Synthesis of Electroluminescent Polymer

(See Chemical Reviewa, Vol. 95, pp. 173-177) known as a carbon-carbon coupling reaction using the monomers M1, M2, M3, M4, M5 and M6 prepared in the above- 1995, p. 2457-2483). The composition and molecular weight of the copolymer are shown in Table 1 below. The weight average molecular weights of Polymer 1, Polymer 2 and Polymer 3 using the monomers M5 and M6 having the new structural units according to the present invention were 390,000 (PDI = 2.5), 520,000 (PDI = 3.2) and 318,000 (PDI = 2.3) , Which is within the molecular weight range that can easily provide devices by solution process.

division Polymer M1
(mol%) M2
(mol%) M3
(mol%) M4
(mol%) M5
(mol%) M6
(mol%) Molecular Weight
(Mw) Molecular Weight
(Mn) PDI Example 1 Polymer 1 15 50 20 12 3 390,000 155,000 2.5 Example 2 Polymer 2 17 50 20 12 One 520,000 163,000 3.2 Example 3 Polymer 3 15.5 50 20 12 2 0.5 318,000 139,000 2.3

Example  4 to Example  6: Fabrication of electroluminescent device

ITO (indium-tin oxide) electrodes were formed on a glass substrate, PEDOT was spin-coated on the ITO electrodes to form thin films and dried. Then, electroluminescence Polymers for devices were spin-coated to form a light emitting layer having a thickness of 700 to 1000 Å. Ba was vacuum-deposited to a thickness of 50 Å on the light-emitting layer, and 1500 Å of aluminum was vacuum-deposited on the light-emitting layer to prepare an electroluminescent device.

division The light- Drive start voltage
(V) Highest efficiency
(cd / A) Highest luminance
(cd / m < 2 & Color coordinates
(x, y) Example 4 Polymer 1 2.8 3.68 12,670 (0.154, 0.205) Example 5 Polymer 2 2.6 3.54 22,940 (0.155, 0.280) Example 6 Polymer 3 2.6 4.14 13,700 0.154, 0.273)

The electroluminescent polymers prepared in Examples 1 to 3 were improved in luminance and electroluminescence efficiency by introducing M5 and M6 having the specific structural units developed in the present invention into the basic structure composed of M1, M2, M3 and M4 Electroluminescent polymers. In the case of the electroluminescent devices manufactured using these, as shown in Table 2, the organic electroluminescent device using the polymer 1 containing 3 mol% of the monomer M5 according to the present invention showed a low starting voltage of 2.8 V , The highest efficiency was 3.68 cd / A, and the color coordinates at 500 cd / m ² emitted light in the blue region with x, y = (0.154, 0.205) and the maximum luminance was as high as 12,670 cd / m ² And exhibited excellent electroluminescence characteristics. The electroluminescent characteristics of Polymer 1 using 3 mol% of M5 are shown in Figs. 6 and 7. Fig.

In addition, the organic electroluminescent device using the polymer 2 containing 1 mol% of the monomer M6 according to the present invention exhibited a low starting voltage of 2.6 V, a maximum efficiency of 3.54 cd / A and a high efficiency of 500 cd / m 2 ² exhibited excellent electroluminescence characteristics such as blue light emission with x, y = (0.155, 0.280) and maximum luminance of 22,940 cd / m ² . Electroluminescence characteristics of Polymer 2 using 1 mol% of M6 are shown in FIGS. 8 and 9. FIG.

The organic electroluminescent device using the polymer 3 polymerized with 2 mol% and 0.5 mol% of the monomers M5 and M6 according to the present invention exhibited a low starting voltage of 2.6 V and a maximum efficiency of 4.14 cd / And blue color emission at x, y = (0.154, 0.273) at 500 cd / m ² and excellent electroluminescence characteristics such as maximum luminance of 13,700 cd / m ² . The electroluminescent properties of Polymer 3 are shown in FIGS. 10 and 11. FIG.

In the organic electroluminescence devices of Examples 4 to 6 using Polymers 1 to 3 according to the present invention, the high luminescence efficiency and the luminance were higher in the structure of monomers M5 and M6 than that of Fluorene Which is a phenomenon caused by the complete inhibition of intermolecular interactions and eximer due to substitution with a hydroxyl group.

From these results, it can be seen that the polymers developed in the present invention have excellent electroluminescence properties such as luminance, color purity and efficiency, which are aspects of commercialization.

As described above, the electroluminescent polymer in which the monomers M5 and M6 according to the present invention are incorporated as a structural unit has remarkably improved luminescence efficiency and brightness, has excellent thermal stability and minimizes intermolecular interaction due to bulky substituents It has excellent luminescence efficiency and excellent solubility and has a good thin film property. Therefore, it has excellent luminescence characteristics when used as a blue light emitting material of an organic electroluminescent device or a host material such as green and red Lt; / RTI >

Claims (6)

An organic electroluminescent polymer represented by any one of the following Chemical Formulas 1 to 3: [Chemical Formula 1]

(2)

(3)

Wherein A is an aryl group which is the same or different and is substituted or unsubstituted with at least one substituent selected from the group consisting of straight or branched chain alkyl and alkoxy groups having 1 to 20 carbon atoms; An aryl group substituted with at least one substituent selected from the group consisting of a straight chain or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si ; Or a straight or branched chain alkyl group having 1 to 20 carbon atoms and at least one hetero atom selected from the group consisting of F, S, N, O, P and Si, and an alkoxy group An aryl group having 2 to 4 hetero rings; Ar is an arylene group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms; R is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms; Ar ₁ is an arylamine group substituted or unsubstituted with at least one substituent selected from the group consisting of a straight-chain or branched-chain alkyl group and an alkoxy group having 1 to 20 carbon atoms; Ar ₂ is selected from the group consisting of (i) C6 to C60 substituted or unsubstituted arylene groups, (ii) C2 to C60 substituents in which at least one hetero atom selected from the group consisting of N, S, O, P and Si is included in the aromatic ring (Iii) C6 to C60 substituted or unsubstituted arylene vinylene groups; And (iv) combinations thereof; And x is an integer of 1 to 10,000, y is an integer of 0 to 10,000, z is an integer of 4 to 100,000, x / y is 1/19 or more, and (x + y) : Having a ratio of 80; x1 is an integer of 1 to 10,000, y1 is an integer of 0 to 10,000, z1 is an integer of 4 to 100,000, x1 / y1 is 1/19 or more, (x1 + y1): z1 is 5:95 to 20 : 80; (k + 1) / m is 1/19 or more, and (k + 1 + m) is an integer of 1 to 10,000, m is an integer of 0 to 10,000, n is an integer of 8 to 100,000, : n has a ratio of 5:95 to 20:80. The organic electroluminescent polymer according to claim 1, wherein A is selected from the following compounds, which are the same or different from each other.

The compound according to claim 1, wherein the substituent of Ar ₂ is a linear or branched alkyl or alkoxy group having 1 to 20 carbon atoms; An aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; Cyano group (-CN); And a silyl group. ≪ RTI ID = 0.0 > 11. < / RTI > The organic electroluminescent polymer according to claim 1, wherein the organic electroluminescent polymer has a weight average molecular weight of 800 to 4,000,000 and a molecular weight distribution of 1 to 10. An organic electroluminescent device comprising at least one layer comprising organic electroluminescent polymers according to any one of claims 1 to 4 between an anode and a cathode, wherein the layer is a hole transporting layer or a light emitting layer. The organic electroluminescent device according to claim 5, wherein the structure of the electroluminescent device is an anode / a light emitting layer / a cathode, an anode / a hole transporting layer / a light emitting layer / a cathode, or an anode / a hole transporting layer / a light emitting layer / an electron transporting layer / a cathode.

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