Method for printing functional layer of electronic device by combining inks

Abstract

The invention relates to a method for printing a functional layer containing at least two different organic functional material A and organic functional material B, comprising the following steps: (a) providing a substrate having at least a first pixel type A, (b) printing a first ink A into the first pixel type A, the first ink A contains at least one organic functional material A and at least one organic solvent A, (c) printing a second ink B into the first pixel type A, the second ink B contains at least one organic functional material B, which is different from the organic functional material A, and at least one organic solvent B, which is different from the organic solvent A and which can be miscible with the organic solvent A at any mixing ratio at room temperature, and (d) subsequently drying the first pixel type A, characterized in that the second ink B contains at least one organic functional material B, which is different from the organic functional material A, and at least one organic solvent B, which is different from the organic solvent A and can be miscible with the organic solvent A at any mixing ratio. The solubility of the organic functional material A in the organic solvent A at room temperature is > = 20 g / l, the solubility of the organic functional material B in the organic solvent B at room temperature is > = 20 g / l, and the solubility of the organic functional material A in the organic solvent B at room temperature is lt; the invention further relates to the ink box.

Description

Technical Field

[0001] The present invention relates to a method for printing, preferably inkjet printing (IJP), a functional layer of an electronic device, preferably an organic light emitting diode (OLED), by combining inks. The OLED produced according to the method can be used for the production of displays, preferably full-color displays. The present invention also relates to an ink cartridge, which can be used in the method according to the present invention. Background Art

[0002] OLED - Organic Light Emitting Diode - displays are extremely thin, lightweight and energy efficient. They provide perfect images at every viewing angle, with extraordinary color brightness and very high contrast. Due to their low energy consumption, small OLED displays are ideal for use in portable devices such as smartphones, digital photo frames and digital cameras. OLED displays are suitable for TVs, monitors, large-area video walls and automotive applications.

[0003] OLED displays consist of an array of individually controlled light-emitting elements, or pixels. For a full-color display, each pixel will consist of red, green, and blue (RGB) light-emitting sub-pixels that can be individually controlled to collectively produce the desired image. In this regard, there are two main approaches to RGB color patterning in OLED displays: (a) juxtaposed RGB OLEDs; and (b) white OLEDs plus color filters. In the first approach, each pixel consists of RGB OLED sub-pixels, and the total light output of each device is not modified and directly contributes to the final image. In the latter case, three white OLED sub-pixels are combined with three color filters.

[0004] The basic OLED unit structure that forms an RGB OLED is usually composed of organic semiconductor molecules deposited between conductive electrodes on a glass substrate or a flexible polymer film substrate. When current flows between the electrodes, electrons and holes are injected into the organic semiconductor, and excitons are generated after two-by-two recombination, which converts the organic molecules into an electronically excited state. They return to the ground state from the electronically excited state by emitting light. The molecular structure of the semiconductor used determines the color of the emitted light. Specifically, the OLED stacked structure contains multiple functional organic layers, including a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. All of these layers are located between the anode and the cathode.

[0005] Breakdown of OLED structure:

[0006] • Substrate (can be plastic, glass or metal foil) – the foundation of the OLED.

[0007] • Anode (may be transparent or not, depending on the type of OLED) – carries a positive charge to inject holes (the absence of electrons) into the organic layers that make up the OLED device.

[0008] • Hole Injection Layer (HIL) – Deposited over the anode, this layer receives holes from the anode and injects them deeper into the device.

[0009] • Hole transport layer (HTL) – This layer supports the transport of holes across it so that the holes can reach the light emitting layer.

[0010] • Light-emitting layer (EML) – the layer that produces light. The EML consists of a luminophore of defined color doped in a host. This is the layer where electrical energy is directly converted into light.

[0011] • Electron transport layer (ETL) – supports the transport of electrons across it so that the electrons can reach the light emitting layer.

[0012] • Electron injection layer (EIL) – This layer receives electrons from the cathode and injects them deeper into the device.

[0013] • Cathode (may or may not be transparent depending on the type of OLED) – carries a negative charge to inject electrons into the organic layers that make up the OLED device.

[0014] The juxtaposition approach provides the best power efficiency since the entire light output of each device is used in image creation. However, this approach requires juxtaposition of RGB OLEDs on the same substrate. Since organic semiconductors are generally not suitable for photolithography processes because they are easily damaged by solvents, making OLEDs using different materials on the same substrate can only be done by thermal deposition of OLED materials using a shadow mask, or in the case of polymers and solution-processable small molecule materials, by printing-based techniques such as inkjet printing.

[0015] OLED inkjet printing is a cost-effective method for manufacturing large OLED displays. OLED inks can be precisely deposited on surfaces, resulting in efficient use of materials. In contrast to the OLED evaporation process, no shadow mask is required. OLED inkjet printing is a less complex process and can be done at room temperature and atmospheric pressure.

[0016] Display manufacturers have great interest in organic light emitting diodes (OLEDs) for display applications. In particular, they are interested in inkjet printed OLED TVs because of their high potential for high performance and potentially low manufacturing costs. The advantages of using inkjet printing technology are highly accurate position and ink volume control, as well as its high throughput for potential mass production. Conventional panels contain at least red, green and blue (R, G and B). Typically, each color has a multilayer device structure. Preferably, it contains an anode, a hole injection layer (HIL), a hole transport layer (HTL), an emitting layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL) and a cathode.

[0017] One of the main challenges of multilayer printing is to determine and adjust the relevant parameters in order to obtain uniform ink deposition on the substrate coupled with good device performance. In particular, the solubility of the materials, the physical parameters of the solvents (surface tension, viscosity, boiling point, etc.), the printing technique, the processing conditions (air, nitrogen, temperature, etc.) and the drying parameters are properties that can greatly affect the pixel pattern and thus the device performance.

[0018] An important application of inkjet printed (IJP) OLEDs is the printing of medium to large high-resolution displays (>200 ppi).

[0019] Technical Problem and Purpose of the Invention

[0020] Due to the fact that pixels are small in high-resolution displays, the volume of ink in a pixel is very limited. Therefore, a high ink concentration is required to achieve the target thickness.

[0021] OLED inks usually contain two or more different solid organic functional materials, which may have different solubility limits in one solvent. As a result, high concentrations of OLED inks run the risk of lower ink stability (shelf life).

[0022] It was therefore an object of the present invention to provide a method for printing functional layers, preferably via inkjet printing, in which on the one hand sufficiently high concentrations of inks are used and on the other hand these inks do not have a low ink stability (shelf life).

[0023] The purpose is to solve the problem that, instead of dissolving the material for one functional layer in one ink and printing it with one ink, which would result in a low ink stability, the material for one functional layer is dissolved in at least two different inks. The different inks can be printed one after another into one pixel. In the pixel, the inks automatically mix. Afterwards, the resulting ink is dried, which is a mixture of the printed inks. Due to the fact that the inks used in the method of the invention are mixed for only a short period of time, problems caused by low ink stability (shelf life) can be avoided.

[0024] Technical Solution

[0025] The present invention relates to a method for printing a functional layer containing at least two different organic functional materials A and organic functional material B, the method comprising the following steps:

[0026] (a) providing a substrate, the substrate having at least a first pixel type A,

[0027] (b) printing a first ink A into the first pixel type A, wherein the first ink A contains at least one organic functional material A and at least one organic solvent A,

[0028] (c) printing a second ink B into the first pixel type A, wherein the second ink B contains at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at any mixing ratio at room temperature, and

[0029] (d) then drying the first pixel type A,

[0030] Features

[0031] The solubility of the organic functional material A in the organic solvent A at room temperature is ≥20 g / l,

[0032] The solubility of the organic functional material B in the organic solvent B at room temperature is ≥ 20 g / l, and

[0033] The solubility of the organic functional material A in the organic solvent B at room temperature is less than 20 g / l.

[0034] The invention also relates to a method for producing an OLED comprising at least a hole injection layer (HIL), a hole transport layer (HTL) and an emitting layer (EML) between a pair of electrodes, characterised in that the emitting layer (EML) is produced according to the method of the invention.

[0035] The invention also relates to a method for producing a display comprising an OLED, characterised in that the OLED is produced according to the method of the invention. In a preferred embodiment of the invention, the display is a full-colour display.

[0036] In addition, the present invention also relates to an ink cartridge, wherein the ink cartridge contains at least two different inks, ink A and ink B,

[0037] - wherein the ink A contains at least a first organic functional material A and at least a first organic solvent A,

[0038] - wherein the ink B contains at least a second organic functional material B and at least a second organic solvent B,

[0039] - wherein the first organic functional material A and the second organic functional material B are different,

[0040] - wherein the first organic solvent A and the second organic solvent B are different,

[0041] - and wherein the organic solvent A and the organic solvent B are miscible with each other in any mixing ratio at room temperature,

[0042] Features

[0043] - the solubility of the organic functional material A in the organic solvent A at room temperature is ≥ 20 g / l,

[0044] - the solubility of the organic functional material B in the organic solvent B at room temperature is ≥ 20 g / l, and

[0045] - The solubility of the organic functional material A in the organic solvent B at room temperature is <20 g / l. DETAILED DESCRIPTION

[0046] The present invention relates to a method for printing a functional layer containing at least two different organic functional materials A and organic functional material B, the method comprising the following steps:

[0047] (a) providing a substrate, the substrate having at least a first pixel type A,

[0048] (b) printing a first ink A into the first pixel type A, wherein the first ink A contains at least one organic functional material A and at least one organic solvent A,

[0049] (c) printing a second ink B into the first pixel type A, wherein the second ink B contains at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at any mixing ratio at room temperature, and

[0050] (d) then drying the first pixel type A,

[0051] Features

[0052] The solubility of the organic functional material A in the organic solvent A at room temperature is ≥20 g / l,

[0053] The solubility of the organic functional material B in the organic solvent B at room temperature is ≥ 20 g / l, and

[0054] The solubility of the organic functional material A in the organic solvent B at room temperature is less than 20 g / l.

[0055] The method of the present invention relates to a method of combining different inks having high concentration and high ink stability to prepare an organic functional layer.

[0056] The method of the present invention can be used to prepare an organic functional layer, the organic functional layer containing two or more solid materials with different solubility (at least a first organic functional material A and at least a second organic functional material B), or at least one organic functional material with low solubility in at least one organic solvent. Using the method of the present invention, a first ink A (wherein the first organic functional material A has good solubility in the first organic solvent A) and a second ink B (wherein the second organic functional material B has good solubility in the second organic solvent B) can be printed into the same pixel to prepare an organic functional layer containing a mixture of the first organic functional material A and the second organic functional material B.

[0057] The method of the present invention can also be used to prepare an organic functional layer containing two or more solid materials with different stability (at least a first organic functional material A and at least a second organic functional material B), or at least one organic functional material with low stability in at least one organic solvent. Using the method of the present invention, a first ink A (wherein the first organic functional material A has good stability in the first organic solvent A) and a second ink B (wherein the second organic functional material B has good stability in the second organic solvent B) can be printed into the same pixel to prepare an organic functional layer containing a mixture of the first organic functional material A and the second organic functional material B. The mixing of the first ink A and the second ink B in the pixel can be achieved within a few minutes, which is much shorter than the shelf life (several months) of an ink containing the first ink and the second ink organic functional materials and solvents. As a result, problems with ink stability can be avoided by utilizing the method of the present invention.

[0058] According to the invention, the substrate has at least one pixel type, a first pixel type A.

[0059] Preferably, the substrate has at least two different pixel types, a first pixel type A and a second pixel type B, more preferably, the substrate has at least three different pixel types, a first pixel type A, a second pixel type B and a third pixel type C. Most preferably, the substrate has three different pixel types, a first pixel type A, a second pixel type B and a third pixel type C.

[0060] The substrate may also have more than three different pixel types, for example four different pixel types, a first pixel type A, a second pixel type B, a third pixel type C and a fourth pixel type D.

[0061] If the substrate contains other pixels different from each other in addition to the first pixel A, such as the second pixel B, the third pixel C and / or the fourth pixel D, at least one layer of the second pixel type B, the third pixel type C and / or the fourth pixel type D can also be printed according to the method of the present application. However, at least one layer of these pixels can also be printed using other known methods.

[0062] In a first preferred embodiment of the present invention, the solubility of the organic functional material B in the organic solvent A at room temperature is <20 g / l.

[0063] The solubility of the organic functional material A in the organic solvent A at room temperature is preferably ≥30 g / l, more preferably ≥40 g / l.

[0064] The solubility of the organic functional material A in the organic solvent B at room temperature is preferably <10 g / l, more preferably <5 g / l.

[0065] The solubility of the organic functional material B in the organic solvent B at room temperature is preferably ≥30 g / l, more preferably ≥40 g / l.

[0066] The solubility of the organic functional material B in the organic solvent A at room temperature is preferably <10 g / l, more preferably <5 g / l.

[0067] The solubility of different organic functional materials in different organic solvents is always measured at room temperature (ie: 20° C.) In addition, the solubility of different organic functional materials is always measured at atmospheric pressure (ie: 1 atm).

[0068] In one embodiment of the method of the present invention, before drying the first pixel A, in addition to the first ink A and the second ink B, at least a third ink C is printed into the first pixel A, wherein the third ink C contains at least one organic functional material C different from the organic functional material A and the organic functional material B and at least one organic solvent C different from the organic solvent A and / or the organic solvent B.

[0069] According to the present application, the printing method can be any printing method known to those skilled in the art, for example, flow coating, dip coating, spray coating, spin coating, screen printing, relief printing, gravure printing, rotary printing, roller coating, flexographic printing, offset printing or nozzle printing. However, the preferred printing method is inkjet printing.

[0070] The printing method of the present application, preferably the inkjet printing method of the present application, is used to produce functional layers of electronic components, preferably functional layers of organic light-emitting diodes (OLEDs).

[0071] The functional layer is preferably a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL) or an electron injection layer (EIL), more preferably an emission layer (EML).

[0072] In a second preferred embodiment of the present invention, at least one organic functional material A and / or at least one organic functional material B is a low molecular weight material having a molecular weight of ≤3,000 g / mol, preferably ≤2,000 g / mol, more preferably ≤1,000 g / mol.

[0073] In a first embodiment of the second preferred embodiment, the at least one organic functional material A and the at least one organic functional material B are different host materials.

[0074] In a second embodiment of the second preferred embodiment, at least one organic functional material A is a host material and at least one organic functional material B is a light emitting material. The light emitting material is selected from fluorescent light emitting materials and phosphorescent light emitting materials.

[0075] In a third embodiment of the second preferred embodiment, at least one organic functional material A and at least one organic functional material B are different luminescent materials. The luminescent materials are selected from fluorescent luminescent materials and phosphorescent luminescent materials.

[0076] According to the method of the present invention, ink A, ink B and optional ink C are printed into the same pixel type to produce an ink containing at least a first organic functional material A, a second organic functional material B and an optional third organic functional material C and at least a first organic solvent A, at least a second organic solvent B and an optional third organic solvent C.

[0077] Based on the total weight of the ink, the content of the organic functional material A, the organic functional material B and / or the organic functional material C in the corresponding ink is ≥2 wt %, preferably ≥3 wt %, more preferably ≥4 wt %.

[0078] Based on the total weight of the ink, the content of organic functional material A, organic functional material B and / or organic functional material C in the corresponding ink is respectively in the range of 1 wt % to 20 wt %, preferably in the range of 2 wt % to 20 wt %, and more preferably in the range of 3 wt % to 20 wt %.

[0079] The boiling points of the organic solvent A, organic solvent B and / or organic solvent C in the corresponding ink are in the range of 100°C to 400°C, preferably in the range of 200°C to 350°C, more preferably in the range of 225°C to 325°C, and most preferably in the range of 250°C to 300°C.

[0080] The viscosity of the first ink, the second ink and / or the third ink is 0.8 mPa . s to 50 mPa . s, preferably within 1 mPa . s to 40 mPa . s, more preferably in the range of 2 mPa . s to 15 mPa . within the range of s.

[0081] The viscosity of the ink and solvent according to the invention was measured using a 1° cone-plate rotational rheometer of the Discovery AR3 model (Thermo Scientific). The device allows precise control of temperature and shear rate. The viscosity was measured at a temperature of 25.0° C. (+ / - 0.2° C.) and a shear rate of 500 s -1 Each sample was measured three times and the measured values ​​were averaged.

[0082] The surface tension of the first ink, the second ink and / or the third ink is respectively in the range of 15 to 70 mN / m, preferably in the range of 10 to 50 mN / m, more preferably in the range of 20 to 40 mN / m.

[0083] Surface tension can be measured using a FTA (First Ten Angstrom) 1000 contact angle goniometer at 20°C. Details of the method are available from First Ten Angstrom as published by Dr. Roger P. Woodward in "Surface tension measurements using the drop-shape method". Preferably, the surface tension can be determined using the hanging drop method. This measurement technique dispenses a drop of liquid from a needle into a bulk liquid or gas phase. The shape of the drop is caused by the relationship between surface tension, gravity, and density differences. Using the hanging drop method, the surface tension is calculated from the shadow image of the hanging drop using http: / / www.kruss.de / services / education-theory / glossary / drop-shape-analysis. A commonly used and commercially available high-precision drop shape analysis tool, the FTA1000 from First Ten Ångstrom, was used to perform all surface tension measurements. The surface tension was determined by the software FTA1000. All measurements were performed at room temperature in the range between 20°C and 25°C. The standard operating procedure involves determining the surface tension of each formulation using a fresh disposable droplet dispensing system (syringe and needle). Each droplet is measured with sixty measurements over a one minute period and then averaged. Three drops are measured for each formulation. The final value is the average of the measurements. The tool is regularly cross-checked against various liquids with known surface tensions.

[0084] In a first preferred embodiment, the method of the present application can be used to prepare a hole injection layer (HIL) of an OLED.

[0085] In the first embodiment, the first ink A contains at least one hole transport material and at least one organic solvent A as an organic functional material.

[0086] As hole transport material, any suitable material customary, in particular for OLEDs, may be used. Preferred materials are described in the present application.

[0087] The at least one hole-transporting material used in the hole injection layer is preferably a polymeric material, preferably having a molecular weight M wIt is ≥10,000 g / mol, more preferably ≥25,000 g / mol, most preferably ≥50,000 g / mol.

[0088] In this first embodiment, the second ink B contains at least one dopant as an organic functional material and at least one solvent B.

[0089] As dopant, any suitable material commonly used, especially for OLED, in particular in combination with the above-mentioned hole transport material can be used, preferably any suitable salt. The term dopant as used herein is also used for the term salt. For example, preferred salts are described in WO 2016 / 107668 A1.

[0090] The at least one dopant is preferably a low molecular weight material, preferably having a molecular weight of ≤3,000 g / mol, more preferably ≤2,000 g / mol, and most preferably ≤1,000 g / mol.

[0091] In the first embodiment, the ratio of the amounts of the two inks, namely, ink A and ink B, can be varied in a very wide range, and the ratio of the hole transport material and the dopant can also be varied in a very wide range.

[0092] The organic solvent A and the organic solvent B may be a single solvent, or may be a mixture of solvents.

[0093] As the organic solvent A and the organic solvent B, any appropriate commonly used organic solvent or organic solvent mixture may be used.

[0094] Preferred solvents and solvent mixtures are described herein.

[0095] In a second preferred embodiment, the method of the present application can be used to prepare a hole transport layer (HTL) of an OLED.

[0096] In this second embodiment, the first ink A contains at least one hole transport material and at least one organic solvent A as an organic functional material, and the second ink B contains at least one hole transport material and at least one organic solvent B as an organic functional material.

[0097] As hole transporting material for the hole transporting layer, any suitable material commonly used, in particular for OLEDs, may be used. Preferred materials are described in the present application.

[0098] As a hole transporting material used for the hole transporting layer, the same hole transporting material as that used for the hole injection layer can be used.

[0099] Each hole transporting material may be a polymer material or a low molecular weight material.

[0100] If the hole transporting material is a polymeric material, it preferably has a molecular weight M w It is ≥10,000 g / mol, more preferably ≥25,000 g / mol, most preferably ≥50,000 g / mol.

[0101] If the at least one hole transporting material is a low molecular weight material, it preferably has a molecular weight of ≤3,000 g / mol, more preferably ≤2,000 g / mol, and most preferably ≤1,000 g / mol.

[0102] In the second embodiment, the ratio of the amounts of the two inks, namely, ink A and ink B, can be varied in a very wide range, and the ratio of the hole transport material and the dopant can also be varied in a very wide range.

[0103] The organic solvent A and the organic solvent B may be a single solvent, or may be a mixture of solvents.

[0104] As the organic solvent A and the organic solvent B, any suitable organic solvent or organic solvent mixture commonly used may be used.

[0105] Preferred solvents and solvent mixtures are described herein.

[0106] In a third preferred embodiment, the method of the present application can be used to prepare an emitting layer (EML) of an OLED.

[0107] In the third embodiment, the first ink A contains at least one light-emitting material and at least one organic solvent A as an organic functional material.

[0108] As the luminescent material, any suitable material commonly used can be used. The luminescent material is selected from fluorescent luminescent materials and phosphorescent luminescent materials. Preferred materials are described in the present application.

[0109] If the luminescent material of the first ink A is a red luminescent material, it is preferably a red luminescent phosphorescent material. Red luminescence according to the present invention refers to emission of light in the range of 600 nm to 750 nm.

[0110] If the luminescent material of the first ink A is a green luminescent material, it is preferably a green luminescent phosphorescent material. Green luminescence according to the present invention refers to emission of light in the range of 500 nm to 570 nm.

[0111] If the luminescent material of the first ink A is a luminescent material emitting blue light, it is preferably a fluorescent luminescent material emitting blue light. The luminescent material emitting blue light according to the present invention refers to emitting light in the range of 420 nm to 480 nm.

[0112] The at least one luminescent material is preferably a low molecular weight material, preferably having a molecular weight of ≤3,000 g / mol, more preferably ≤2,000 g / mol, most preferably ≤1,000 g / mol.

[0113] In this third embodiment, the second ink A contains at least one matrix material as an organic functional material and at least one organic solvent A.

[0114] As the matrix material, any suitable material commonly used may be used. Preferred materials are described in the present application.

[0115] The at least one matrix material is preferably a low molecular weight material, preferably having a molecular weight of ≤3,000 g / mol, more preferably ≤2,000 g / mol, most preferably ≤1,000 g / mol.

[0116] According to a third embodiment, the method of the present invention is used to prepare an emitting layer (EML) of an OLED. In addition to one emitting material and one host material, the emitting layer may contain at least one further emitting material and / or at least one further host material. Preferably, the emitting layer contains another emitting material or another host material.

[0117] If the emitting layer contains two emitting materials (so-called double doping) and a matrix material, the first emitting material is preferably a red-emitting phosphorescent emitting material and the second emitting material is preferably a green-emitting phosphorescent emitting material.

[0118] If the emitting layer contains two matrix materials (so-called mixed hosts) and an emitting material, the emitting material is a phosphorescent emitting material emitting red or green light, or a fluorescent emitting material emitting blue light.

[0119] If the light emitting layer contains at least a third material, this material (ie, organic functional material C) can be printed as a third ink C as described above, or can be printed as a component of ink A or ink B, depending on its solubility in different solvents.

[0120] In the third embodiment, the ratio of the amounts of the two inks, namely, ink A and ink B, can be varied in a very wide range, and the ratio of the hole transport material and the dopant can also be varied in a very wide range.

[0121] In the case of a third preferred embodiment in which the method of the present invention is used to prepare an emitting layer (EML) of an OLED, the previously formed layer in direct contact with the EML is typically a hole transport layer (HTL) containing at least one organic functional material H, i.e. a hole transporting material. If the solubility of the organic functional material H in the organic solvent A of the first ink A at room temperature is <20 g / l, preferably <10 g / l, more preferably <5 g / l, then the method of the present application can be used to apply an emitting layer on top of the hole transport layer without causing any significant damage to the hole transport layer, even if the organic functional material is not a cross-linking material.

[0122] Therefore, another object of the present invention is a method for printing two functional layers, wherein the first functional layer contains at least one, preferably one, organic functional material H and the second functional layer contains at least two different organic functional materials A and organic functional materials B, the method comprising the following steps:

[0123] (a) providing a substrate, the substrate having at least a first pixel type A,

[0124] (b) printing ink H into the first pixel type A, wherein the ink H contains at least one organic functional material H and at least one organic solvent H,

[0125] (c) then drying the first pixel A,

[0126] (d) then printing a first ink A into the first pixel type A, the first ink A containing at least one organic functional material A and at least one organic solvent A, and

[0127] (e) printing a second ink B into the first pixel type A, wherein the second ink B contains at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at any mixing ratio at room temperature, and

[0128] (f) then drying the first pixel type A,

[0129] Features

[0130] The solubility of the organic functional material A in the organic solvent A at room temperature is ≥20 g / l,

[0131] The solubility of the organic functional material B in the organic solvent B at room temperature is ≥ 20 g / l,

[0132] The solubility of the organic functional material A in the organic solvent B at room temperature is less than 20 g / l, and

[0133] The solubility of the organic functional material H in the organic solvent A is less than 20 g / l.

[0134] The solubility of the organic functional material H in the organic solvent A at room temperature is preferably <10 g / l, more preferably <5 g / l.

[0135] The organic solvent H may be a single solvent, or may be a mixture of solvents.

[0136] As the organic solvent H, any suitable conventional organic solvent or organic solvent mixture may be used.

[0137] Preferred solvents and solvent mixtures are described herein.

[0138] The present invention also relates to a method for producing an OLED, which contains at least a hole injection layer (HIL), a hole transport layer (HTL) and an emission layer (EML) between a pair of electrodes, wherein preferably the hole injection layer (HIL), the hole transport layer (HTL) or the emission layer (EML), more preferably the emission layer (EML) is produced according to the method of the present invention.

[0139] The invention furthermore relates to a method for producing a display, preferably a full-color display, which contains an OLED, wherein the OLED is produced according to the method of the invention.

[0140] According to the method of the invention, ink A and ink B and optionally ink C and ink H are used. Each of these inks contains at least one organic functional material that can be used to produce a functional layer of an electronic device. The functional material is generally an organic material introduced between the anode and cathode of an electronic device, preferably an OLED.

[0141] The term organic functional material refers in particular to organic conductors, organic semiconductors, organic fluorescent compounds, organic phosphorescent compounds, organic light absorbing compounds, organic photosensitizers and other organic photoactive compounds. The term organic functional material also includes organic metal complexes of transition metals, rare earths, lanthanides and actinides.

[0142] The organic functional material is preferably an organic semiconductor selected from the following: hole injection material (HIM), hole transport material (HTM), hole blocking material (HBM), electron injection material (EIM), electron transport material (ETM), electron blocking material (EBM), exciton blocking material (ExBM), host material, luminescent material and metal complex.

[0143] Preferred embodiments of the organic functional material are disclosed in detail in WO 2011 / 076314 A1.

[0144] In a more preferred embodiment, the organic semiconductor is a light-emitting material selected from fluorescent light-emitting bodies and phosphorescent light-emitting bodies.

[0145] According to the present application, the term luminophore refers to a material that, after excitation, which can occur by any type of energy transfer, allows a radiative transition to the ground state to emit light. In general, two classes of luminophores are known, namely fluorescent and phosphorescent luminophores. The term fluorescent luminophore refers to a material or compound that undergoes a radiative transition from an excited singlet state to the ground state. The term phosphorescent luminophore preferably refers to a luminescent material or compound containing a transition metal.

[0146] Emitters are often also referred to as dopants if the dopant causes the above-mentioned properties in the system. The dopant in a system comprising a matrix material and a dopant is considered to mean the component with the smaller proportion in the mixture. Correspondingly, the matrix material in a system comprising a matrix material and a dopant is considered to mean the component with the larger proportion in the mixture. Thus, the term phosphorescent emitter can also be considered to mean, for example, a phosphorescent dopant.

[0147] The organic functional material may be a low molecular weight compound, a polymer, an oligomer or a dendrimer, wherein the organic functional material may also be in the form of a mixture. Thus, the ink used according to the method of the present invention may contain two or more different low molecular weight compounds, a low molecular weight compound and a polymer or two polymers (blend).

[0148] If the organic functional material is a low molecular weight compound, its molecular weight is preferably ≤3,000 g / mol, more preferably ≤2,000 g / mol, most preferably ≤1,000 g / mol.

[0149] If the organic functional material is a polymer compound, its molecular weight M w Preferably it is ≥10,000 g / mol, more preferably ≥25,000 g / mol, most preferably ≥50,000 g / mol.

[0150] The molecular weight M of the polymer is w Preferably, it is in the range of 10,000 to 2,000,000 g / mol, more preferably in the range of 25,000 to 1,000,000 g / mol, most preferably in the range of 50,000 to 300,000 g / mol. w Determined by GPC (= gel permeation chromatography) against internal polystyrene standards.

[0151] The emitter material is preferably selected from the classes of organic electroluminescent emitter materials outlined elsewhere within this application.

[0152] The organic functional materials according to the present application are often characterized by their molecular frontier orbitals, namely: the highest occupied molecular orbital (HOMO) (sometimes also referred to as the valence band) and the lowest unoccupied molecular orbital (LUMO) (sometimes also referred to as the conduction band). The HOMO and LUMO energy levels are conventionally measured (e.g. by XPS = X-ray photoelectron spectroscopy, UPS = ultraviolet photoelectron spectroscopy or CV = cyclic voltammetry) or calculated (by quantum chemical methods, such as (time-dependent) DFT = density functional theory), which are known to those skilled in the art. Those skilled in the art are also aware of the fact that the absolute values ​​of these energy levels depend significantly on the method used. The applicant has established a compatible joint method to determine the energy levels of organic semiconductors. The HOMO / LUMO energy levels of a group of semiconductors (more than 20 different semiconductors) are measured by CV using a reliable evaluation method, and are also calculated by DFT using Gaussian03W with the same correction functional, such as B3PW91 and the same basis set, such as 6-31G (d). The calculated values ​​are then calibrated according to the measured values. Such calibration factors are used for further calculations. The agreement between the calculated and measured values ​​is very good. Therefore, the comparison of energy levels in this application is based on the correct basis. The energy gap or band gap is obtained by the difference between the HOMO and LUMO energy levels.

[0153] The ink according to the present invention may contain one or more organic functional materials selected from hole injection materials (HIMs). HIMs refer to materials or units that can promote holes (i.e., positive charges) injected from the anode into the organic layer or anode. Typically, the HIM has a HOMO energy level comparable to or higher than the work function of the anode, i.e., -5.3 eV or higher.

[0154] The ink according to the present invention may contain one or more organic functional materials selected from hole transport materials (HTMs). HTMs refer to materials or units that are capable of transporting holes (i.e., positive charges) injected from hole injection materials or anodes. HTMs typically have a high HOMO, typically above -5.4 eV. In many cases, depending on the adjacent layers, a HIM can also function as an HTM.

[0155] The ink according to the present invention may contain one or more organic functional materials selected from hole blocking materials (HBM). HBM refers to a material that, if deposited adjacent to a light-emitting layer or a hole transporting layer in a multilayer structure, blocks the flow of holes. Typically, its HOMO is lower than the HOMO level of the HTM in the adjacent layer. The hole blocking layer is often inserted between the light-emitting layer and the electron transporting layer in an OLED.

[0156] The ink according to the present invention may contain one or more organic functional materials selected from electron injection materials (EIMs). EIMs refer to materials that can promote the electrons (i.e., negative charges) injected from the cathode into the organic layer. EIMs generally have a LUMO energy level that is comparable to or lower than the work function of the cathode. Typically, the LUMO of an EIM is lower than -2.6 eV.

[0157] The ink according to the present invention may contain one or more organic functional materials selected from electron transport materials (ETMs). ETMs refer to materials that are capable of transporting electrons (i.e., negative charges) injected from an EIM or cathode. ETMs typically have a low LUMO, typically below -2.7 eV. In many cases, depending on the adjacent layers, an EIM may also act as an ETM.

[0158] The ink according to the present invention may contain one or more organic functional materials selected from electron blocking materials (EBM). EBM refers to a material that, if deposited adjacent to a light-emitting layer or an electron transporting layer in a multilayer structure, blocks the flow of electrons. Typically, its LUMO is higher than the LUMO of the EBM in the adjacent layer.

[0159] The ink according to the present invention may contain one or more organic functional materials selected from exciton blocking materials (ExBM). An ExBM refers to a material that, if deposited adjacent to a light-emitting layer in a multilayer structure, blocks the flow of excitons. The ExBM should have a higher triplet energy level or singlet energy level than the light-emitting layer or other adjacent layers.

[0160] The ink according to the present invention may comprise one or more organic functional materials selected from luminophores. The term luminophore refers to a material that emits light by undergoing radiative decay after receiving excitation energy from other materials by any type of energy transfer or by forming excitons by means of electricity or light. There are two types of luminophores, fluorescent and phosphorescent luminophores. The term fluorescent luminophore relates to a material or compound that undergoes a radiative transition from an excited singlet state to its ground state. The term phosphorescent luminophore as used herein relates to a luminescent material or compound comprising a transition metal. This generally includes materials that emit light by spin-forbidden transitions, for example transitions from an excited triplet state.

[0161] The ink according to the present invention may contain one or more organic functional materials selected from metal complexes. According to quantum mechanics, the transition from an excited state with a high spin multiplicity, for example, from an excited triplet state to the ground state is forbidden.

[0162] However, the presence of heavy atoms such as iridium, osmium, platinum and europium leads to strong spin-orbit coupling, i.e., excited singlet and triplet states mix, so that the triplet state acquires certain singlet properties; if the singlet-triplet mixing produces a faster radiative decay rate than non-radiative events, then the luminance can be efficient. As first reported by Baldo et al.; Nature 395, 151-154 (1998), this type of luminescence can be achieved using metal complexes. Other metal complexes can also play the role of efficient and broadband light-absorbing materials or dyes, such as the Ru complex reported by B. O'Regan & M. Graetzel, Nature 353, 737 (1991).

[0163] The term dopant as used herein is also used in the term emitter or emitter material.

[0164] The ink according to the present invention may contain one or more organic functional materials selected from the host material. The host material is usually used in combination with a luminophore, and generally speaking, the energy gap between HOMO and LUMO is larger than that of the luminophore material. In addition, the host material can act as an electron transport material, or can act as a hole transport material. The host material can also have both electron transport and hole transport properties. In the case where the photoluminescence of the OLED is mainly caused by singlet transitions, it is very desirable to have a maximum overlap between the absorption spectrum of the luminophore and the photoluminescence spectrum of the host material. This ensures that energy is transferred from the host material to the luminophore.

[0165] The host material is also called matrix or host material. Preferably, the host refers to the host used in combination with the phosphorescent emitter in the OLED. For copolymers containing emitter units, the polymer backbone has the same meaning as the host.

[0166] In addition to the HIMs mentioned elsewhere herein, suitable HIMs are: phenylenediamine derivatives (US 3615404), arylamine derivatives (US 3567450), amino-substituted chalcone derivatives (US 3526501), styrylanthracene derivatives (JP Showa 54 (1979) 110837), hydrazone derivatives (US 3717462), acylhydrazones, stilbene derivatives (JP Showa 61 (1986) 210363), silazane derivatives (US 4950950), polysilane compounds (JP Heisei 2 (1990) 204996), PVK and other conductive macromolecules, copolymers based on aniline (JP Heisei 2 (1990) 282263), conductive macromolecular thiophene oligomers (JP Heisei 1 (1989) 211399), PEDOT:PSS (spin-coated polymer), plasma deposited fluorocarbon polymers (US 6127004, US 6208075, US 6208077), porphyrin compounds (JP Showa 63 (1988) 2956965, US 4720432), aromatic tertiary amines and styrylamines (US 4127412), benzidine-type triphenylamines, styrylamine-type triphenylamines and diamine-type triphenylamines. Aromatic amine dendrimers (JP Heisei 8 (1996) 193191) can also be used, and phthalocyanine derivatives, naphthalocyanine derivatives or butadiene derivatives are also suitable.

[0167] Preferably, the HIM is selected from monomeric organic compounds comprising amines, triarylamines, thiophenes, carbazoles, phthalocyanines, porphyrins and derivatives thereof.

[0168] Particularly preferred are aromatic tertiary amines (US 2008 / 0102311 A1), for example N,N'-diphenyl-N,N'-di(3-tolyl)benzidine (=4,4'-bis[N-3-methylphenyl]-N-phenylamino)biphenyl (NPD) (US 5061569), N,N'-bis(N,N'-diphenyl-4-aminophenyl)-N,N-diphenyl-4,4'-diamino-1,1'-biphenyl (TPD 232) and 4,4',4''-tris[(3-methylphenyl)phenylamino]-triphenylamine (MTDATA) (JP Heisei 4 (1992) 308688) or phthalocyanine derivatives (e.g., H2Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, ClGaPc, ClInPc, ClSnPc, Cl2SiPc, (HO)AlPc, (HO)GaPc, VOPc, TiOPc, MoOPc, GaPc-O-GaPc).

[0169] Particularly preferred are the triarylamine compounds of the following formulae 1 (TPD 232), 2, 3 and 4, which may also be substituted, and other compounds as disclosed in US Pat. No. 7,399,537 B2, US 2006 / 0061265 A1, EP 1661888 B1 and JP 08292586 A.

[0170]

[0171] Further compounds suitable as hole injection materials are disclosed in EP 0891121 A1 and EP 1029909 A1. Hole injection layers are generally described in US 2004 / 0174116.

[0172] In principle, any HTM known to a person skilled in the art can be used in the formulation according to the invention. In addition to the HTMs mentioned elsewhere herein, the HTMs are preferably selected from amines, triarylamines, thiophenes, carbazoles, phthalocyanines, porphyrins, isomers and derivatives thereof. The HTMs are particularly preferably selected from amines, triarylamines, thiophenes, carbazoles, phthalocyanines and porphyrins. Suitable materials for the hole transporting layer are: phenylenediamine derivatives (US 3615404), arylamine derivatives (US 3567450), amino-substituted chalcone derivatives (US 3526501), styrylanthracene derivatives (JP A 56-46234), polycyclic aromatic compounds (EP 1009041), polyarylalkane derivatives (US 3615402), fluorenone derivatives (JP A 54-110837), hydrazone derivatives (US 3717462), stilbene derivatives (JP A 61-210363), silazane derivatives (US 4950950), polysilane (JP A 2-204996), aniline copolymer ... 2-282263), thiophene oligomers, polythiophene, PVK, polypyrrole, polyaniline and other copolymers, porphyrin compounds (JP A63-2956965), aromatic dimethylidene compounds, carbazole compounds such as CDBP, CBP, mCP, aromatic tertiary amines and styrylamine compounds (US 4127412), and monomeric triarylamines (US 3180730). Even more triarylamino groups may also be present in the molecule.

[0173] Preferred are aromatic tertiary amines containing at least two tertiary amine units (U.S. Pat. No. 4,720,432 and U.S. Pat. No. 5,061,569), for example, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD) (U.S. Pat. No. 5,061,569) or MTDATA (JP A 4-308688), N,N,N',N'-tetrakis(4-biphenyl)diaminobiphenylidene (TBDB), 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane (TAPC), 1,1-bis(4-di-p-tolylaminophenyl)-3-phenylpropane (TAPPP), 1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl]benzene (BDTAPVB), N , N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl (TTB), TPD, N,N,N',N'-tetraphenyl-4,4'''-diamino-1,1':4',1'':4'',1'''-tetraphenyl, tertiary amines containing carbazole units are also preferred, for example, 4(9H-carbazole-9-yl)-N,N-bis[4-(9H-carbazole-9-yl)phenyl]aniline (TCTA). Hexaazaterphenyl compounds according to US 2007 / 0092755 A1 are also preferred.

[0174] Particularly preferred are triarylamine compounds of the following formulae 5 to 10, which may also be substituted, and compounds as disclosed in the following documents: EP 1162193 B1, EP 650955 B1, Synth. Metals 1997, 91(1-3), 209, DE 19646119 A1, WO 2006 / 122630 A1, EP 1860097 A1, EP 1834945 A1, JP08053397 A, US 6251531 B1, and WO 2009 / 041635 A1.

[0175]

[0176] In principle, any HBM known to the person skilled in the art can be used in the formulation according to the invention. In addition to the HBMs mentioned elsewhere in this document, suitable hole-blocking materials are metal complexes (US 2003 / 0068528), for example bis(2-methyl-8-hydroxyquinolinate)(4-phenylphenolate)aluminum(III) (BAlQ). Fa-tris(1-phenylpyrazolinate-N,C2)iridium(III) (Ir(ppz)3) is also used for this purpose (US 2003 / 0175553 A1). Phenanthroline derivatives, for example BCP, or phthalimides, for example TMPP, are also used.

[0177] Suitable hole-blocking materials are furthermore described in WO 00 / 70655 A2, WO 01 / 41512 and WO 01 / 93642 A1.

[0178] In principle, any EIM known to the person skilled in the art can be used in the formulations according to the invention. In addition to the EIMs mentioned elsewhere herein, according to the invention it is also possible to use EIMs comprising at least one organic compound selected from the group consisting of metal complexes of 8-hydroxyquinoline, heterocyclic organic compounds, fluorenone, fluorenylidene methane, perylenetetracarboxylic acid, anthraquinone dimethane, diphenoquinone, anthrone, anthraquinone diethylenediamine, isomers and derivatives thereof.

[0179] Metal complexes of 8-hydroxyquinoline, such as Alq3 and Gaq3, can be used as EIMs for the electron injection layer. Reductive doping with alkali or alkaline earth metals, such as Li, Cs, Ca or Mg, at the interface with the cathode is advantageous. Preferred are combinations including Cs, such as Cs and Na, Cs and K, Cs and Rb, or Cs, Na and K.

[0180] Heterocyclic organic compounds, such as 1,10-phenanthroline derivatives, benzimidazoles, thiopyran dioxides, oxadiazoles, triazoles, imidazoles or oxadiazoles are also suitable. Examples of suitable nitrogen-containing five-membered rings are oxadiazoles, thiazoles, oxadiazoles, thiadiazoles, triazoles and compounds disclosed in US 2008 / 0102311 A1.

[0181] Preferred EIMs are selected from compounds of formulae 11 to 13, which may be substituted or unsubstituted.

[0182]

[0183] For example, organic compounds such as fluorenone, fluorenylidene methane, perylenetetracarboxylic acid, anthraquinone dimethane, diphenoquinone, anthrone, and anthraquinone diethylenediamine can also be used.

[0184]

[0185] In principle, any ETM known to those skilled in the art can be used in the formulations according to the invention. In addition to the ETMs mentioned elsewhere herein, suitable ETMs are selected from imidazoles, pyridines, pyrimidines, pyridazines, pyrazines, oxadiazoles, quinolines, quinoxalines, anthracenes, benzanthracenes, pyrenes, perylenes, benzimidazoles, triazines, ketones, phosphine oxides, phenazines, phenanthrolines, triarylboranes, isomers and derivatives thereof.

[0186] Suitable ETMs for the electron transport layer are: metal chelates of 8-hydroxyquinoline (e.g., Liq, Alq3, Gaq3, Mgq2, Znq2, Inq3, Zrq4), Balq, 4-azaphenanthren-5-ol / Be complexes (US 5529853 A; e.g., Formula 16), butadiene derivatives (US 4356429), heterocyclic optical brighteners (US 4539507), indoles, e.g., 1,3,5-tris(2-N-phenyl-benzimidazolyl)benzene (TPBI) (US 5766779, Formula 17), 1,3,5-triazine, pyrene, anthracene, tetracene, fluorene, spirobifluorene, dendrimers, tetracene such as rubrene derivatives, 1,10-phenanthroline derivatives (JP 2003 / 115387, JP 2004 / 311184, JP2001 / 267080, WO 2002 / 043449), silyl-cyclopentadiene derivatives (EP 1480280, EP 1478032, EP1469533), pyridine derivatives (JP 2004 / 200162 Kodak), phenanthrolines, such as BCP and Bphen, and many phenanthrolines bonded via biphenyl or other aromatic groups (US 2007 / 0252517 A1) or bonded to anthracene (US 2007 / 0122656 A1, such as formula 18 and 19), 1,3,4-oxadiazoles, such as formula 20, triazoles, such as formula 21, triarylboranes, such as also having silicon (such as formula 48), benzimidazole derivatives and other N-heterocyclic compounds (see US 2007 / 0273272 A1), silylene derivatives, borane derivatives, Ga-type oxine complexes.

[0187]

[0188] Preference is given to 2,9,10-substituted anthracenes (substituted by 1-naphthyl or 2-naphthyl and 4-biphenyl or 3-biphenyl) or molecules containing two anthracene units (US 2008 / 0193796 A1).

[0189] Likewise preferred are anthracene-benzimidazole derivatives, such as compounds of formulae 22 to 24, and compounds disclosed, for example, in US Pat. No. 6,878,469 B2, US 2006 / 147747 A and EP 1551206 A1.

[0190]

[0191] In principle, any EBM known to the person skilled in the art can be used in the formulations according to the invention. In addition to the EBMs mentioned elsewhere herein, transition metal complexes, such as Ir(ppz)3 (US 2003 / 0175553) can be used as material for the electron blocking layer.

[0192] Preferably, the EBM is also selected from amines, triarylamines and derivatives thereof.

[0193] It is known to those skilled in the art that the choice of an ExBM suitable for a formulation according to the invention depends on the energy gap of the adjacent layer. A suitable ExBM should have a larger energy gap than the functional material in the adjacent layer, whether singlet or triplet, which is preferably a light-emitting layer. In addition to the ExBMs mentioned elsewhere herein, substituted triarylamines, such as MTDATA or 4,4',4''-tris(N,N-diphenylamino)triphenylamine (TDATA), can be used as ExBMs for electron blocking layers. Substituted triarylamines are described, for example, in US 2007 / 0134514 A1.

[0194] N-substituted carbazole compounds, such as TCTA, or heterocyclic compounds, such as BCP, are also suitable.

[0195] Metal complexes, such as Ir(ppz)3 or Alq3, can likewise be used for this purpose.

[0196] In principle, any host material known to the person skilled in the art can be used in the formulations according to the invention. Depending on the type of emitter used, host materials can be divided into two categories, hosts for fluorescent emitters and hosts for phosphorescent emitters, the latter often being referred to as matrix or host material.

[0197] The formulation according to the invention may also comprise more than one host material, preferably it comprises 3 host materials, more preferably it comprises 2 host materials, most preferably it comprises one host material. If the formulation according to the invention comprises at least two host materials, the host materials are also referred to as co-hosts or co-host materials.

[0198] Preferred host materials suitable for fluorescent emitters are selected from anthracene, benzanthracene, indenofluorene, fluorene, spirobifluorene, phenanthrene, dehydrophenanthrene, thiophene, triazine, imidazole and their derivatives.

[0199] Particularly preferred host materials for fluorescent emitters are selected from the following classes: oligoarylidenes (for example 2,2',7,7'-tetraphenylspirobifluorene according to EP 676461, or dinaphthylanthracene), in particular oligoarylidenes containing condensed aromatic groups, for example phenanthrene, tetracene, coronene, lettuce, fluorene, spirofluorene, perylene, phthaloperylene, naphthoperylene, decacyclene, rubrene, oligoarylidenevinylene (for example 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) or 4,4-bis-2,2-diphenylvinyl-1,1-spirobiphenyl (spiro-DPVBi) according to EP 676461), polypodal metal complexes (for example 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) according to WO 676461), polyarylidenevinylene (for example 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) or 4,4-bis-2,2-diphenylvinyl-1,1-spirobiphenyl (spiro-DPVBi) according to WO 676461), polyarylidenevinylene (for example 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) according to EP ...-spirobiphenyl (spiro-DPVBi) according to WO 6 2004 / 081017), in particular metal complexes of 8-hydroxyquinoline, for example tris(8-hydroxyquinolinate)aluminum(III) (aluminum quinolinate, Alq3) or bis(2-methyl-8-hydroxyquinolinate)-4-(phenylphenoxy)aluminum, also imidazole chelates (US 2007 / 0092753 A1) and quinoline metal complexes, aminoquinoline-metal complexes, benzoquinoline-metal complexes, hole-conducting compounds (for example according to WO 2004 / 058911), electron-conducting compounds, in particular ketones, phosphine oxides, sulfoxides and the like (for example according to WO 2005 / 084081 and WO 2005 / 084082), atropisomers (for example according to WO 2006 / 048268), boronic acid derivatives (for example according to WO 2006 / 117052) or benzanthracene (for example DE 102007024850). Particularly preferred host materials are selected from the following classes: oligoaryl subunits containing naphthalene, anthracene, benzanthracene and / or pyrene, or atropisomers of these compounds, ketones, phosphine oxides, and sulfoxides. Very particularly preferred host materials are selected from the following classes: oligoaryl subunits containing anthracene, benzanthracene and / or pyrene, or atropisomers of these compounds. For the purposes of this application, an oligoaryl subunit is taken to mean a compound in which at least three aryl groups or aryl subunits are bonded to one another.

[0200] Other preferred host materials for fluorescent emitters are particularly selected from compounds of formula 25,

[0201]

[0202] in

[0203] Ar 4 ,Ar 5 ,Ar 6 is, identically or differently on each occurrence, an aryl or heteroaryl group having 5 to 30 aromatic ring atoms, which may be substituted by one or more radicals, and

[0204] p is 1, 2, or 3,

[0205] If p = 1, then Ar 4 ,Ar 5 and Ar 6 The sum of the π electrons in is at least 30. If p=2, the sum of the π electrons is at least 36. If p=3, the sum of the π electrons is at least 42.

[0206] Among the host materials of Formula 25, Ar 5 The group represents anthracene, which may be replaced by one or more R 1 group substituted, and Ar 4 and Ar 6 The groups are bonded in positions 9 and 10. Very particularly preferably, Ar 4 and / or Ar 6 At least one of the groups is a fused aryl group selected from: 1-naphthyl or 2-naphthyl, 2-phenanthrenyl, 3-phenanthrenyl or 9-phenanthrenyl, or 2-benzanthryl, 3-benzanthryl, 4-benzanthryl, 5-benzanthryl, 6-benzanthryl or 7-benzanthryl, each of which may be substituted by one or more R 1 Group substitution. US 2007 / 0092753 A1 and US 2007 / 0252517 A1 describe anthracene-based compounds, such as 2-(4-methylphenyl)-9,10-di(2-naphthyl)anthracene, 9-(2-naphthyl)-10-(1,1'-biphenyl)anthracene and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene, 9,10-diphenylanthracene, 9,10-bis(phenylethynyl)anthracene and 1,4-bis(9'-ethynylanthryl)benzene. Also preferred are host materials containing two anthracene units (US 2008 / 0193796 A1), such as 10,10'-bis[1,1',4',1'']terphenyl-2-yl-9,9'-bianthracene.

[0207] Other preferred host materials are derivatives of the following compounds: arylamines, styrylamines, fluorescein, perylene, phthalacetylenone, naphthylperylene, diphenylbutadiene, tetraphenylbutadiene, cyclopentadiene, tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, coumarin, oxadiazole, bisbenzooxazoline, oxazinone, pyridine, pyrazine, imine, benzothiazole, benzooxazole, benzimidazole (US 2007 / 0092753 A1), for example 2,2',2''-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole], aldazine, stilbene, styrylarylene derivatives, for example 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene, and distyrylarylene derivatives (US 5121029), stilbene, vinylanthracene, diaminocarbazole, pyran, thiopyran, diketopyrrolopyrrole, polymethine, merocyanine, acridones, quinacridones, cinnamates, and fluorescent dyes.

[0208] Particularly preferred are derivatives of arylamines and styrylamines, for example 4,4′-bis[N-(1-naphthyl)-N-(2-naphthyl)amino]biphenyl (TNB).

[0209] Preferred compounds having oligoaromatic subunits as hosts for fluorescent emitters are the compounds disclosed, for example, in US 2003 / 0027016 A1, US 7326371 B2, US 2006 / 043858 A, US 7326371 B2, US 2003 / 0027016 A1, WO 2007 / 114358, WO 2008 / 145239, JP 3148176 B2, EP 1009044, US 2004 / 018383, WO 2005 / 061656 A1, EP 0681019 B1, WO 2004 / 013073 A1, US 5077142, WO 2007 / 065678 and US 2007 / 0205412 A1. Particularly preferred oligoarylene-based compounds are compounds of formulae 26 to 32.

[0210]

[0211]

[0212] Other host materials of the fluorescent emitter can be selected from spirobifluorene and its derivatives, such as spiro-DPVBi disclosed in EP 0676461 and indenofluorene disclosed in US Pat. No. 6,562,485.

[0213] Preferred host materials, ie matrix materials, of phosphorescent emitters are selected from ketones, carbazoles, triarylamines, indenofluorenes, fluorenes, spirobifluorenes, phenanthrene, dehydrophenanthrene, thiophene, triazines, imidazoles and derivatives thereof. Some preferred derivatives are described in more detail below.

[0214] If a phosphorescent emitter is used, for example, as an electroluminescent component of an organic light emitting diode (OLED), the host material must satisfy quite a few properties compared to the host material for a fluorescent emitter. The host material for a phosphorescent emitter needs to have a triplet energy level that is more energetic than the triplet energy level of the emitter. The host material can transport electrons or holes, or both. In addition, in order to fully promote singlet-triplet mixing, the emitter should have a large spin-orbit coupling constant. This can be achieved by using a metal complex.

[0215] Preferred matrix materials are: N,N-biscarbazolylbiphenyl (CBP), carbazole derivatives (for example according to WO 2005 / 039246, US 2005 / 0069729, JP 2004 / 288381, EP 1205527 or DE 102007002714), azacarbazoles (for example according to EP 1617710, EP 1617711, EP 1731584, JP 2005 / 347160), ketones (for example according to WO 2004 / 093207), phosphine oxides, sulfoxides and sulfones (for example according to WO 2005 / 003253), oligophenylenes, aromatic amines (for example according to US 2005 / 0069729), bipolar matrix materials (for example according to WO 2007 / 137725), silanes (for example according to WO 2005 / 111172), 9,9-diarylfluorene derivatives (for example according to DE 102008017591), borazolidines or boric esters (for example according to WO 2006 / 117052), triazole derivatives, oxadiazole and oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, distyrylpyrazine derivatives, thiopyran dioxide derivatives, phenylenediamine derivatives, aromatic tertiary amines, styrylamines, indoles, anthrone derivatives, fluorenone derivatives, fluorenylidene methane derivatives, hydrazone derivatives, silazane derivatives, aromatic dimethylidene compounds, porphyrin compounds, carbodiimide derivatives, diphenylquinone derivatives, phthalocyanine derivatives, metal complexes of 8-hydroxyquinoline derivatives, such as Alq3, wherein the 8-hydroxyquinoline complex may also contain a triarylaminophenol ligand (US 2007 / 0134514 A1), various metal complex-polysilane compounds with metal phthalocyanine, benzophenone oxazole or benzothiazole as ligands, hole conducting polymers such as poly(N-vinylcarbazole) (PVK), aniline copolymers, thiophene oligomers, polythiophene, polythiophene derivatives, polyphenylene derivatives, polyfluorene derivatives.

[0216] Other particularly preferred matrix materials are selected from compounds containing indolocarbazole and its derivatives (e.g., formulae 33 to 39), such as those disclosed in DE 102009023155.2, EP 0906947 B1, EP 0908787 B1, EP 906948 B1, WO 2008 / 056746 A1, WO 2007 / 063754 A1, WO 2008 / 146839 A1, and WO 2008 / 149691 A1.

[0217]

[0218]

[0219] Examples of preferred carbazole derivatives are: 1,3-N,N-dicarbazolebenzene (=9,9'-(1,3-phenylene)bis-9H-carbazole) (mCP), 9,9'-(2,2'-dimethyl[1,1'-biphenyl]-4,4'-diyl)bis-9H-carbazole (CDBP), 1,3-bis(N,N'-dicarbazole)benzene (=1,3-bis(carbazole-9-yl)benzene), PVK (polyvinylcarbazole), 3,5-di(9H-carbazole-9-yl)biphenyl, and compounds of formulae 40 to 44.

[0220]

[0221] Preferred Si tetraaryl compounds are, for example, compounds of formulae 45 to 50 (US 2004 / 0209115, US 2004 / 0209116, US 2007 / 0087219 A1, US 2007 / 0087219 A1).

[0222]

[0223]

[0224] Particularly preferred hosts for phosphorescent dopants are compounds of the formula 51 (EP 652273 B1).

[0225]

[0226] Further particularly preferred matrix materials for phosphorescent dopants are selected from the compounds of the formula 52 (EP 1923448 B1).

[0227]

[0228] wherein M, L and n are as defined in the reference. Preferably, M is Zn, L is a quinolinium anion q, and n is 2, 3 or 4. Very particular preference is given to [Znq2]2, [Znq2]3 and [Znq2]4.

[0229] Preferred are co-hosts selected from metal-based oxinoid complexes, among which lithium quinolate (Liq) or Alq3 are particularly preferred.

[0230] The luminophore compound needs to have a smaller band gap than the host compound. Generally speaking, a smaller band gap can be obtained by expanding the π-electron system of the conjugated molecular system. Therefore, the luminophore compound tends to have a more extended conjugated π-electron system than the host molecule. Many examples have been disclosed, for example: the styrylamine derivatives disclosed in JP 2913116 B and WO 2001 / 021729A1, and the indenofluorene derivatives disclosed in WO 2008 / 006449 and WO 2007 / 140847.

[0231] The blue fluorescent emitter is preferably: a polyaromatic compound, for example 9,10-di(2-naphthylanthracene) and other anthracene derivatives, derivatives of the following compounds: tetracene, xanthene, perylene, for example 2,5,8,11-tetra-tert-butylperylene, phenylene, for example 4,4'-bis(9-ethyl-3-carbazolylvinylidene)-1,1'-biphenyl, fluorene, arylpyrene (US 2006 / 0222886), arylvinylidene (US 5121029, US 5130603), derivatives of the following compounds: rubrene, coumarin, rhodamine, quinacridone such as N,N'-dimethylquinacridone (DMQA), dicyanomethylidene pyran such as 4-(dicyanoethylidene)-6-(4-dimethylaminophenylvinyl-2-methyl)-4H-pyran (DCM), thiopyran, polymethyl, pyranyl cation salts and thiopyranyl cation salts, diindenoperylene, indenoperylene, bis(azinyl)imine-boron compounds (US 2007 / 0092753 A1), bis(azinyl)methylidene compounds, and quinolone compounds.

[0232] Other preferred blue fluorescent emitters are described in CH Chen et al.: “Recent developments inorganic electroluminescent materials” Macromol. Symp. 125, (1997) 1-48 and “Recent progress of molecular organic electroluminescent materials and devices” Mat. Sci. and Eng. R, 39 (2002), 143-222.

[0233] Preferred fluorescent dopants according to the invention are selected from the following classes: monostyrylamines, distyrylamines, tristyrylamines, tetrastyrylamines, styrylphosphines, styrylethers and arylamines.

[0234] Monostyrylamine is taken to mean a compound containing one substituted or unsubstituted styryl group and at least one amine, preferably an aromatic amine. Distyrylamine is taken to mean a compound containing two substituted or unsubstituted styryl groups and at least one amine, preferably an aromatic amine. Tristyrylamine is taken to mean a compound containing three substituted or unsubstituted styryl groups and at least one amine, preferably an aromatic amine. Tetrastyrylamine is taken to mean a compound containing four substituted or unsubstituted styryl groups and at least one amine, preferably an aromatic amine. The styryl groups are particularly preferably stilbenes, which may also be further substituted. The corresponding phosphines and ethers are defined similarly to the amines. For the purposes of the present invention, arylamines or aromatic amines are taken to mean compounds containing three substituted or unsubstituted aromatic or heteroaromatic ring systems directly bonded to nitrogen. At least one of these aromatic or heteroaromatic ring systems is preferably a fused ring system, which preferably has at least 14 aromatic ring atoms. Preferred examples thereof are aromatic anthraceneamine, aromatic anthracenediamine, aromatic pyreneamine, aromatic pyrenediamine, aromatic leucamine and aromatic leucadiamine. Aromatic anthraceneamine is taken to mean a compound in which one diarylamino group is directly bonded to an anthracene group, preferably in the 9-position. Aromatic anthracenediamine is taken to mean a compound in which two diarylamino groups are directly bonded to an anthracene group, preferably in the 9- and 10-positions. Aromatic pyreneamine, pyrenediamine, leucamine and leucadiamine are defined analogously, with the diarylamino groups on pyrene preferably being bonded in the 1-position or in the 1,6-positions.

[0235] Other preferred fluorescent dopants are selected from indenofluorenamines and indenofluorenediamines, for example according to WO 2006 / 122630, benzoindenofluorenamines and benzoindenofluorenediamines, for example according to WO 2008 / 006449, and dibenzoindenofluorenamines and dibenzoindenofluorenediamines, for example according to WO 2007 / 140847.

[0236] Examples of dopants from the class of styrylamines are substituted or unsubstituted tristilbenzylamines or the dopants described in WO 2006 / 000388, WO 2006 / 058737, WO 2006 / 000389, WO 2007 / 065549 and WO 2007 / 115610. Distyrylbenzene derivatives and distyrylbiphenyl derivatives are described in US 5121029. Other styrylamines are found in US 2007 / 0122656 A1.

[0237] Particularly preferred styrylamine dopants and triarylamine dopants are compounds of formulae 53 to 58 and compounds as disclosed in US Pat. No. 7,250,532 B2, DE 102005058557 A1, CN 1583691 A, JP 08053397 A, US Pat. No. 6,251,531 B1 and US Pat. No. 2006 / 210830 A.

[0238]

[0239] Other preferred fluorescent dopants are selected from triarylamines as disclosed in EP 1957606 A1 and US 2008 / 0113101 A1.

[0240] Other preferred fluorescent dopants are selected from derivatives of the following compounds: naphthalene, anthracene, tetracene, fluorene, diindenoperylene, indenoperylene, phenanthrene, perylene (US 2007 / 0252517 A1), pyrene, lettuce, decacyclene, coronene, tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, fluorene, spirofluorene, rubrene, coumarin (US 4769292, US 6020078, US 2007 / 0252517 A1), pyran, oxadiazine, benzoxazole, benzothiazole, benzimidazole, pyrazine, cinnamate, diketopyrrolopyrrole, acridone and quinacridone (US 2007 / 0252517 A1).

[0241] Among the anthracene compounds, particularly preferred are 9,10-substituted anthracenes, such as 9,10-diphenylanthracene and 9,10-bis(phenylethynyl)anthracene. 1,4-bis(9'-ethynylanthracenyl)benzene is also a preferred dopant.

[0242] Examples of phosphorescent emitters are disclosed in the following applications: WO 00 / 70655, WO 01 / 41512, WO 02 / 02714, WO 02 / 15645, EP 1191613, EP 1191612, EP 1191614 and WO 2005 / 033244. In general, all phosphorescent complexes which are used in phosphorescent OLEDs according to the prior art and which are known to the person skilled in the art in the field of organic electroluminescence are suitable, and the person skilled in the art will be able to use other phosphorescent complexes without inventive step.

[0243] The phosphorescent emitter may be a metal complex, preferably having the formula M(L)z, wherein M is a metal atom, L is independently of one another at each occurrence an organic ligand bonded or coordinated to M via one, two or more positions, z is an integer ≥1, preferably 1, 2, 3, 4, 5 or 6, and wherein, optionally, these groups are attached to the polymer via one or more, preferably one, two or three positions, preferably via the ligand L.

[0244] M is in particular a metal atom selected from transition metals, preferably from transition metals of group VIII, or lanthanides, or actinides, particularly preferably from Rh, Os, Ir, Pt, Pd, Au, Sm, Eu, Gd, Tb, Dy, Re, Cu, Zn, W, Mo, Pd, Ag or Ru, very particularly preferably from Os, Ir, Ru, Rh, Re, Pd or Pt. M may also be Zn.

[0245] Preferred ligands are 2-phenylpyridine derivatives, 7,8-benzoquinoline derivatives, 2-(2-thienyl)pyridine derivatives, 2-(1-naphthyl)pyridine derivatives or 2-phenylquinoline derivatives. All of these compounds can be substituted, for example, for blue, by fluorine or trifluoromethyl substituents. The auxiliary ligand is preferably acetylacetonate or picric acid.

[0246] In particular, a complex of Pt or Pd with a tetradentate ligand of formula 59 as disclosed in US 2007 / 0087219 A1 (where R 1 To R 14 and Z 1 To Z 5As defined in this reference), Pt porphyrin complexes with an enlarged ring system (US 2009 / 0061681 A1) and Ir complexes are suitable, for example: 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin-Pt(II), tetraphenyl-Pt(II)-tetrabenzoporphyrin (US 2009 / 0061681 A1) A1), cis-bis(2-phenylpyridinium-N,C2')Pt(II), cis-bis(2-(2'-thienyl)pyridinium-N,C3')Pt(II), cis-bis(2-(2'-thienyl)quinolinium-N,C5')Pt(II), (2-(4,6-difluorophenyl)-pyridinium-N,C2')Pt(II) acetylacetonate, or tris(2-phenylpyridinium-N,C2')Ir(III) (Ir(ppy)3, green), bis(2-phenylpyridinium-N,C2)Ir(III) acetylacetonate (Ir(ppy)2 acetylacetonate, green, US 2001 / 0053462 A1, Baldo, Thompson et al., Nature 403, (2000), 750-753), bis(1-phenylisoquinolinato-N,C2')(2-phenylpyridinato-N,C2')iridium(III), bis(2-phenylpyridinato-N,C2')(1-phenylisoquinolinato-N,C2')iridium(III), bis(2-(2'-benzothienyl)pyridinato-N,C3')iridium(III) acetylacetonate, bis(2- (4',6'-difluorophenyl)pyridinium-N,C2')iridium(III) methylpyridinium (FIrpic, blue), bis(2-(4',6'-difluorophenyl)pyridinium-N,C2')Ir(III)tetrakis(1-pyrazolyl)borate, tris(2-(biphenyl-3-yl)-4-tert-butylpyridinium)iridium(III), (ppz)2Ir(5phdpym)(US 2009 / 0061681 A1), (45ooppz)2Ir(5phdpym) (US 2009 / 0061681 A1), derivatives of 2-phenylpyridine-Ir complexes, such as bis(2-phenylquinolyl-N,C2')iridium(III) acetylacetonate (PQIr), tris(2-phenylisoquinolyl-N,C)Ir(III) (red), bis(2-(2'-benzo[4,5-a]thienyl)pyridinium-N,C3)Ir acetylacetonate ([Btp2Ir(acac)], red, Adachi et al., Appl. Phys. Lett. 78 (2001), 1622-1624).

[0247]

[0248] Also suitable are trivalent lanthanides such as Tb3+ and Eu 3+ complexes (J. Kido et al., Appl. Phys. Lett. 65 (1994), 2124, Kido et al., Chem. Lett. 657, 1990, US 2007 / 0252517 A1), or phosphorescent complexes of Pt(II), Ir(I), Rh(I) with succinonitrile dithiol anion (Johnson et al., JACS 105, 1983, 1795), Re(I) tricarbonyl diimide complexes (Wrighton, JACS 96, 1974, 998, etc.), complexes of OS(II) with cyano ligands and bipyridine or phenanthroline ligands (Ma et al., Synth. Metals 94, 1998, 245) or Alq3 without a host.

[0249] Other phosphorescent emitters with tridentate ligands are described in US 6824895 and US 7029766. Red-emitting phosphorescent complexes are mentioned in US 6835469 and US 6830828.

[0250] Particularly preferred phosphorescent dopants are compounds of formula 60 and other compounds disclosed, for example, in US 2001 / 0053462 A1.

[0251] Particularly preferred phosphorescent dopants are compounds of formula 61 and other compounds disclosed, for example, in WO 2007 / 095118 A1.

[0252]

[0253] Other derivatives are described in US 7378162 B2, US 6835469 B2 and JP 2003 / 253145 A.

[0254] In addition to the metal complexes mentioned elsewhere herein, suitable metal complexes according to the invention may be selected from transition metals, rare earth elements, lanthanides and actinides, which are also the subject of the present invention. Preferably, the metal is selected from Ir, Ru, Os, Eu, Au, Pt, Cu, Zn, Mo, W, Rh, Pd or Ag.

[0255] The ink according to the present invention may also contain an organic functional material selected from polymers, oligomers, dendritic macromolecules and blends. The functional polymer is characterized in that different functions can be incorporated into a macromolecule or a blend of macromolecules. The function is especially one of a hole injection material, a hole transport material, an electron blocking material, a luminescent material, a hole blocking material, an electron injection material, an electron transport material and a dye. The functions incorporated into the polymer can be classified into different groups. By selecting the desired functional groups and the ratios therebetween, the polymer can be adjusted to have the desired functions.

[0256] The distinction between polymers, oligomers and dendrimers arises from the size, size distribution and branching of the molecular entities as defined above.

[0257] Different structures are in particular those disclosed and extensively listed in WO 2002 / 077060 A1 and DE 10337346 A1. The structural units can be derived, for example, from the following classes:

[0258] Type 1: Units which increase the hole injection and / or transport properties of the polymer; it corresponds to a HIM or HTM as described above.

[0259] Category 2: Units which increase the electron injection and / or transport properties of the polymer; it corresponds to the EIM or ETM as described above.

[0260] Category 3: A unit that has a combination of individual units of categories 1 and 2.

[0261] Class 4: Units which modify the emission properties to such an extent that electrophosphorescence instead of electrofluorescence is obtained; generally, this corresponds to a phosphorescent emitter or, more preferably, a luminescent metal complex as described above.

[0262] Class 5: Units which improve the transition from the so-called singlet state to a higher spin state, for example to the triplet state.

[0263] Class 6: Units that influence the morphology and / or emission color of the resulting polymer.

[0264] Class 7: Units that are generally used as main chains and may have an electron transport function, a hole transport function, or both functions.

[0265] Class 8: Units that absorb strongly at at least one wavelength from UV to IR. It corresponds to dye materials as described above.

[0266] Preferably, the organic functional material is a hole transport or injection polymer comprising type 1 units, the type 1 units are preferably selected from units comprising low molecular weight HTMs or HIMs as described above.

[0267] Other preferred class 1 units are, for example, derivatives of triarylamines, benzidines, tetraaryl-p-phenylenediamines, carbazoles, azules, thiophenes, pyrroles and furans, and other O-, S- or N-containing heterocycles with a high HOMO. These arylamines and heterocycles preferably produce a HOMO in the polymer above 5.8 eV (relative to the vacuum level), particularly preferably above 5.5 eV.

[0268] Preferred polymeric HTM or HIM are polymers comprising at least one repeating unit of formula 62 below.

[0269]

[0270] in

[0271] Ar 1 may be the same or different in different repeating units and independently represent a single bond or an optionally substituted mononuclear or polynuclear aromatic group,

[0272] Ar 2 may be the same or different in different repeating units and independently represent an optionally substituted mononuclear or polynuclear aryl group,

[0273] Ar 3 may be the same or different in different repeating units and independently represent an optionally substituted mononuclear or polynuclear aryl group, and

[0274] m is 1, 2 or 3.

[0275] Examples of polymeric HTMs are disclosed in WO 2007 / 131582 A1 and WO 2008 / 009343 A1.

[0276] Preferably, the organic functional material is an electron transport or injection polymer comprising a second type unit, and the second type unit is preferably selected from the group comprising a low molecular weight ETM or EIM as described above.

[0277] Other preferred second class units with electron injection or electron transport properties are, for example, derivatives of pyridine, pyrimidine, pyridazine, pyrazine, oxadiazole, quinoline, quinoxaline and phenazine, and also triarylboranes and other O-, S- or N-containing heterocycles with a low LUMO. These units preferably produce a LUMO in the polymer below 2.7 eV (relative to the vacuum level), particularly preferably below 2.8 eV.

[0278] Preferably, the organic functional material is a polymer comprising a class 3 unit in which structures that increase hole mobility and electron mobility (i.e., class 1 and class 2 units) are directly bonded to each other. Some of these units can act as luminophores and convert the luminescent color to green, yellow or red. Therefore, their use is suitable for, for example, producing other luminescent colors or broadband luminescence from an originally blue-emitting polymer.

[0279] Preferably, the organic functional material is a polymer comprising units of class 4, which are preferably selected from the group comprising phosphorescent emitters, in particular luminescent metal complexes as described above. Particularly preferred here are corresponding structural units containing elements of groups 8 to 10 (Ru, Os, Rh, Ir, Pd, Pt).

[0280] Preferably, the organic functional material is a polymeric triplet matrix comprising units of class 5, which can improve the transition from the singlet state to the triplet state and serve to assist the structural units of class 4, improving the phosphorescent properties of these structural units. Suitable for this purpose are in particular carbazole and bridged carbazole dimer units, as described in DE 10304819 A1 and DE 10328627 A1. Also suitable for this purpose are ketones, phosphine oxides, sulfoxides, sulfones, silane derivatives and similar compounds, as described in DE 10349033 A1. Other preferred structural units can be selected from the group comprising low molecular weight phosphorescent matrices as described above.

[0281] Preferably, the organic functional material is a polymer comprising class 6 units, which affect the morphology and / or emission color of the polymer. In addition to the above-mentioned classes, the polymer also has at least one other aromatic structure or another conjugated structure that does not belong to the above-mentioned classes, that is, the other aromatic structure or another conjugated structure has little effect on the charge carrier mobility, is not an organic metal complex or has no effect on the singlet-triplet transition. Structural units of this type can affect the morphology and / or emission color of the generated polymer. Therefore, depending on the unit, these polymers can also be used as luminophores. In the case of fluorescent OLEDs, preferred are aromatic structures with 6 to 40 C atoms or also preferably derivatives of diphenylvinylene, stilbene or bisphenylvinyl aromatic subunits, each of which can be replaced by one or more R 1 Particularly preferred here are derivatives incorporating a 1,4-phenylene, 1,4-naphthalene, 1,4-anthracene or 9,10-anthracene, 1,6-pyrene, 2,7-pyrene or 4,9-pyrene, 3,9-perylene or 3,10-perylene, 4,4'-biphenylene, 4,4''-terphenylene, 4,4'-bi-1,1'-naphthalene, 4,4'-tolanthracene, 4,4'-stilbene or 4,4''-bis-styrylarene.

[0282] Preferably, the organic functional material is a polymer comprising a Class 7 unit containing an aromatic structure having 6 to 40 C atoms which is generally used as a polymer main chain. These are, for example, 4,5-dihydropyrene derivatives, 4,5,9,10-tetrahydropyrene derivatives, fluorene derivatives as disclosed, for example, in US Pat. No. 5,962,631, WO 2006 / 052457 A2 and WO 2006 / 118345 A1, 9,9′-spirobifluorene derivatives as disclosed, for example, in WO 2003 / 020790 A1, 9,10-phenanthrene derivatives as disclosed, for example, in WO 2005 / 104264 A1, 9,10-dihydrophenanthrene derivatives as disclosed, for example, in WO 2005 / 014689 A2, 5,7-dihydrodibenzoxepinane derivatives as well as cis- and trans-indenofluorene derivatives as disclosed, for example, in WO 2004041901 A1, WO 2004113412 A2, and 1,2-dihydro-2-indenofluorene derivatives as well as 1,2-dihydro-2-indenofluorene derivatives as disclosed, for example, in WO 2004041901 A1, WO 2004113412 A2. The binaphthylidene derivatives of WO 2006 / 063852 A1, and other units disclosed in, for example, WO 2005 / 056633 A1, EP 1344788 A1, WO 2007 / 043495 A1, WO 2005 / 033174 A1, WO 2003 / 099901 A1 and DE 102006003710.

[0283] Other preferred structural units of Class 7 are selected from: fluorene derivatives disclosed in, for example, US 5,962,631, WO 2006 / 052457 A2 and WO 2006 / 118345 A1, spirobifluorene derivatives disclosed in, for example, WO 2003 / 020790 A1, benzofluorene, dibenzofluorene, benzothiophene, dibenzofluorene and their derivatives disclosed in, for example, WO 2005 / 056633 A1, EP 1344788 A1 and WO 2007 / 043495 A1.

[0284] Preferably, the organic functional material is a polymer comprising Class 8 units, the Class 8 units being selected from the group comprising dye materials as described above. Conjugated polymers suitable for organic solar cells, for example, as summarized by FC Krebs in Solar Energy Materials and Solar Cells, Vol. 91, 953 (2007), can also be used as the other organic functional materials in the present invention.

[0285] Preference is given to polymers suitable for use according to the invention which simultaneously comprise one or more units selected from classes 1 to 8. It may likewise be preferred for more than one structural unit from one class to be present simultaneously.

[0286] Preference is given to polymers suitable for use according to the invention which, in addition to the structural units of the emitter, comprise at least one structural unit of the abovementioned classes. Particular preference is given to at least two structural units from different classes of the abovementioned structural units.

[0287] If present in the polymer, the proportion of the different types of radicals is preferably in each case at least 5 mol %, particularly preferably in each case at least 10 mol %. In particular, one of these structural units is selected from hole-conducting units and the other group is an emitting unit, wherein both functions (hole-conducting and emitting) can also be assumed by the same unit.

[0288] However, for example, a smaller proportion of emitting units, in particular green and red emitting units, may also be preferred in order to synthesize white emitting copolymers. The synthesis of white emitting copolymers is described in detail in DE 10343606 A1.

[0289] In order to ensure sufficient solubility, it is preferred that an average of at least 2 non-aromatic C atoms are present in the substituent per repeat unit. Preference is given to at least 4, particularly preferably at least 8 C atoms. In addition, individual C atoms may be replaced by O or S. However, this may well mean that a certain proportion of the repeat units do not carry any further non-aromatic substituents.

[0290] In order to avoid impairment of the film morphology, it is preferred that no long-chain substituents have more than 12 C atoms in the linear chain, particularly preferably no substituent has more than 8 C atoms, in particular no substituent has more than 6 C atoms.

[0291] The polymer used as the organic functional material in the present invention may be a statistical or random copolymer, an alternating or regioregular copolymer, a block copolymer, or a combination thereof.

[0292] In another preferred embodiment, the polymer is a side chain type non-conjugated polymer, which is particularly important for polymer-based phosphorescent OLEDs. Generally speaking, such phosphorescent polymers are obtained by free radical copolymerization of vinyl compounds and contain at least one phosphorescent emitter unit and at least one charge transport unit on the side chain, as disclosed in US7250226 B2. Other examples of such phosphorescent polymers are disclosed in, for example, JP 2007 / 211243 A2, JP2007 / 197574 A2, US 7250226 B2 and JP 2007 / 059939 A.

[0293] In another preferred embodiment, the polymer is a main chain non-conjugated polymer, wherein the main chain units are connected via spacers on the main chain. Like the side chain non-conjugated polymer, the main chain non-conjugated polymer also has a high triplet energy level. An example of a triplet OLED based on a main chain non-conjugated polymer is disclosed in DE 102009023154.

[0294] In another embodiment, the polymer may also be a non-conjugated polymer for fluorescent OLEDs. Preferred singlet non-conjugated polymers are side chain type polymers having anthracene, benzanthracene and derivatives thereof in the side chain, as disclosed in JP2005 / 108556, JP 2005 / 285661 and JP 2003 / 338375.

[0295] The polymer may also serve as an ETM or HTM, and preferably the polymer is a non-conjugated polymer.

[0296] The device according to the invention may also contain additional layers which are not deposited by using the ink according to the invention. The additional layers may be deposited by techniques from solution or by vapor deposition. The specific method adopted therefore depends on the characteristics of the material used and the skilled person has no problem choosing the appropriate technique. The deposited material may be any material used in the field of electronic and optoelectronic multilayer structures. In particular, the material may be any material described herein. Furthermore, the material may be selected from organic and inorganic functional materials as described below.

[0297] Inorganic compounds, such as p-type Si and p-type SiC, and inorganic oxides, such as vanadium oxide (VO x ), molybdenum oxide (MoO x ) or nickel oxide (NiO x ), can also be used as a HIM.

[0298] The electron injection layer (EIL) is often composed of an insulator and a semiconductor.

[0299] Preferred alkali metal chalcogenides for EIL are Li2O, LiO, Na2S, Na2Se, NaO, K2O, and Cs2O.

[0300] Preferred alkaline earth metal chalcogenides for the EIL are CaO, BaO, SrO, BeO, BaS and CaSe.

[0301] Preferred alkali metal halides for the EIL are LiF, NaF, KF, CsF, LiCl, KCl, and NaCl.

[0302] Preferred alkaline earth halides for the EIL are CaF2, BaF2, SrF2, MgF2 and BeF2.

[0303] Likewise, alkali metal complexes, alkaline earth metal complexes, rare earth metals (Sc, Y, Ce, Th, Yb), rare earth metal complexes, rare earth metal compounds (preferably YbF3, ScF3, TbF3), etc. can be used.

[0304] The structure of EIL is described in, for example, US 5608287, US 5776622, US 5776623, US 6137223, US 6140763, US 6914269.

[0305] The electron transport layer may consist of an intrinsic material or contain a dopant. Alq3 (EP 278757 B1) and Liq (EP0569827 A2) are examples of intrinsic layers. 4,7-diphenyl-1,10-phenanthroline (Bphen):Li 1:1 (US 2003 / 02309890) and rubrene / LiF are examples of doped layers.

[0306] According to the method of the present invention, ink A, ink B and ink H are used, and ink C and other inks, such as ink D, are optionally used. Each of these inks contains at least one of organic solvent A, organic solvent B, organic solvent C and organic solvent D.

[0307] The solvent A, solvent B, solvent C, and solvent D used in different inks are different from each other.

[0308] Furthermore, the solvent A, solvent B, solvent C, solvent D, and solvent H used in different inks may be a single solvent, or may be a mixture of two or more different solvents.

[0309] As solvent, any suitable common solvent, in particular for printing OLEDs, can be used. Preferred solvents are described in the present application. The solvent only needs to meet the requirements regarding the solubility of the corresponding organic functional material.

[0310] The determination of the solubility of a material in a solvent can be carried out according to ISO specification 7579:2009, which describes the determination of solubility by photometric or gravimetric methods. The photometric technique is recommended and used here because the boiling points of the solvents considered and used are above 120°C.

[0311] The boiling points of organic solvent A, organic solvent B and organic solvent H and optional solvent C and solvent D are each in the range of 120°C to 400°C, preferably in the range of 200°C to 350°C, more preferably in the range of 225°C to 325°C, most preferably in the range of 250°C to 300°C.

[0312] Preferred solvents for ink A, ink B, ink C, ink D and ink H are independent of each other, and preferred organic solvents include ketones, ethers, esters, amides such as di-C 1-2 Alkylformamides, sulfur compounds, nitro compounds, hydrocarbons, halogenated hydrocarbons (for example, chlorinated hydrocarbons), aromatic or heteroaromatic hydrocarbons (for example, naphthalene derivatives), and halogenated aromatic or heteroaromatic hydrocarbons.

[0313] More preferred solvents can be selected from one of the following categories: substituted and unsubstituted aromatic ethers or linear ethers, such as 3-phenoxytoluene or anisole; substituted and unsubstituted aromatic hydrocarbon derivatives, such as cyclohexylbenzene; substituted and unsubstituted aromatic esters or linear esters, such as butyl benzoate or ethyl p-toluate; substituted or unsubstituted indanes, such as hexamethylindanes; substituted and unsubstituted aromatic ketones or linear ketones, such as dicyclohexyl ketone; substituted and unsubstituted heterocyclic compounds, such as pyrrolidone, pyridine, pyrazine; other fluorinated or chlorinated aromatic hydrocarbons, substituted or unsubstituted naphthalenes, such as alkyl-substituted naphthalenes, such as 1-ethylnaphthalene.

[0314] Particularly preferred solvents are, for example, 1-ethyl-naphthalene, 2-ethyl-naphthalene, 2-propyl-naphthalene, 2-(1-methylethyl)-naphthalene, 1-(1-methylethyl)-naphthalene, 2-butyl-naphthalene, 1,6-dimethyl-naphthalene, 2,2'-dimethyl-biphenyl, 3,3'-dimethyl-biphenyl, 1-acetyl-naphthalene, 1,2,3,4-tetramethyl-benzene, 1,2,3,5-tetramethyl-benzene, 1,2,4,5-tetramethyl-benzene, 1,2,4-trichloro-benzene, 1,2-dihydro-naphthalene, 1,2-dimethyl-naphthalene, 1,3-benzodioxolane, 1,3-diisopropyl-benzene, 1,3-dimethyl-naphthalene, 1,4-benzodioxane, 1,4-diisopropyl-benzene, 1,4-dimethyl-naphthalene, 1,5-dimethyl-tetralin, 1-benzothiophene, thio-naphthalene, 1-bromo-naphthalene, Naphthalene, 1-chloromethylnaphthalene, 1-methoxynaphthalene, 1-methylnaphthalene, 2-bromo-3-bromomethylnaphthalene, 2-bromomethylnaphthalene, 2-bromonaphthalene, 2-ethoxynaphthalene, 2-isopropylanisole, 3,5-dimethylanisole, 5-methoxyindane, 5-methoxyindole, 5-tert-butylm-xylene, 6-methylquinoline, 8-methylquinoline, acetophenone, benzothiazole, benzyl acetate, butylphenyl ether, butyl benzoate, ethyl p-toluate, cyclohexylbenzene, decahydronaphthol, dimethoxytoluene, 3-phenoxytoluene, diphenyl ether, propiophenone, hexylbenzene, hexamethylindane, isochroman, phenyl acetate, acetophenone, o-dimethoxybenzene, pyrrolidone, N,N-dibutylaniline, cycloethyl hexanoate, menthyl isovalerate, dicyclohexyl ketone, ethyl laurate, ethyl decanoate.

[0315] In addition to the above-mentioned components, especially organic functional materials and solvents, the inks according to the invention may also contain other additives and processing aids. These include, in particular, surface-active substances (surfactants), lubricants and greases, viscosity-modifying additives, conductivity-increasing additives, dispersants, hydrophobic agents, adhesion promoters, flow improvers, defoamers, deaerators, diluents which may be reactive or non-reactive, fillers, auxiliaries, processing aids, dyes, pigments, stabilizers, sensitizers, nanoparticles and inhibitors.

[0316] In addition to the above materials, the organic electroluminescent device according to the present invention may also comprise at least one anode, at least one cathode and one or more substrates. For the purpose of the present invention, the electrodes (cathode, anode) are selected in such a way that their energy band energies correspond as closely as possible to the energy band energies of the adjacent organic layers to ensure efficient electron or hole injection.

[0317] Preferred materials for the anode are metal oxides selected from, but not limited to, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO), ZnO, InO, aluminum zinc oxide (AlZnO) and other metal oxides such as zinc oxide doped aluminum zinc oxide and indium zinc oxide, magnesium indium oxide, and nickel tungsten oxide. Metal nitrides such as gallium nitride, and metal selenides such as zinc selenide, and metal sulfides such as zinc sulfide may also be used. Other materials that may be used for the anode are conductive polymers, for example: polythiophene and polypyrrole.

[0318] The anode can be transparent, opaque or reflective. The anode can also adopt intermediate states, for example: partially reflective and partially transparent.

[0319] If the anode is not transparent or only partially transparent, other conductive materials can be used. Preferred materials for non-transparent or partially transparent anodes are selected from, but not limited to, Au, Ir, Mo, Pd, Pt, Cu, Ag, Sn, C, Al, V, Fe, Co, Ni, W and mixtures thereof. The conductive materials can also be mixed with other conductive materials as described above, such as In-Cu.

[0320] The anode is preferably transparent, and a particularly preferred material for the anode is ITO. In the case of a bottom-emitting device, it is preferred to coat glass or plastic with ITO. In the case of a top-emitting device, the anode preferably comprises a reflective material. Other materials can also be used for the anode, which is known to those skilled in the art.

[0321] Flexible and transparent substrate and anode combinations are described, for example, in US 5844363 B2 and US 6602540 B2.

[0322] The cathode can be transparent, opaque or reflective. The cathode is selected from a metal or alloy with a low work function. Preferably, a metal, alloy, or conductive compound or material with a work function less than 4.0 eV is used. Particularly preferred cathodes are selected from, but not limited to, Ba, Ca, Sr, Yb, Ga, Cd, Si, Ta, Sb, Zn, Mg, Al, In, Li, Na, Cs, Ag, a mixture of two or more elements such as an alloy comprising Mg / Al or Al / Li or Al / Sc / Li or Mg / Ag or a metal oxide such as ITO or IZO.

[0323] Other preferred cathode materials for forming the thin dielectric layer are selected from metals mixed with LiF, Li2O, BaF2, MgO or NaF. A typical combination is LiF / Al.

[0324] Mg / Al cathodes with an ITO layer on top are described in US 5703436, US 5707745, US 6548956 B2, US 6576134 B2. Mg / Ag alloys are described in US 4885221.

[0325] As substrate, any kind of material known to those skilled in the art can be used. The substrate can be rigid or flexible. It can be transparent, translucent, opaque or reflective. The material used can be glass, plastic, ceramic or metal foil, wherein the flexible substrate preferably uses plastic and metal foil. However, semiconductor materials, such as organosilicon wafers or printed circuit board (PCB) materials can also be used to simplify the generation of conductive tapes. Other substrates can also be used.

[0326] The glass used may be, for example, soda-lime glass, glass containing Ba or Sr, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass or quartz.

[0327] The plastic plate may be composed of, for example, polycarbonate resin, acrylic resin, vinyl chloride resin, polyethylene terephthalate resin, polyimide resin, polyester resin, epoxy resin, phenolic resin, silicone resin, fluorine resin, polyether sulfide resin, or polysulfone resin.

[0328] As the transparent film, a transparent film made of, for example, polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polypropylene, polystyrene, polymethyl methacrylate, PVC, polyvinyl alcohol, polyvinyl butyral, nylon, polyetheretherketone, polysulfone, polyethersulfone, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polyvinyl fluoride, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, polyester, polycarbonate, polyurethane, polyimide or polyetherimide is used.

[0329] The substrate is provided with a hydrophobic layer. The substrate is preferably transparent.

[0330] Other materials than those mentioned here may also be used. Suitable materials are known to those skilled in the art.

[0331] After applying at least two inks of the invention, for example, the first ink A and the second ink B, to the substrate or the already applied functional layer, a drying step is performed to remove the solvent. In order to avoid bubble formation and obtain a uniform coating, the drying can preferably be performed at a relatively low temperature and over a relatively long time. The drying can preferably be performed over 10 -6 mbar to 1 mbar, more preferably 10 -6 mbar to 10 -2 mbar range, most preferably 10 -6 mbar to 10 -4 During the drying process, the temperature of the substrate can vary from -5°C to 40°C.

[0332] This process can also be repeated several times to form different or identical functional layers. Crosslinking of the functional layer formed can be carried out here to prevent its dissolution, for example, as disclosed in EP 0637899 A1.

[0333] The present invention also relates to an ink cartridge, the ink cartridge containing at least two different inks, ink A and ink B,

[0334] - wherein the ink A contains at least a first organic functional material A and at least a first organic solvent A,

[0335] - wherein the ink B contains at least a second organic functional material B and at least a second organic solvent B,

[0336] - wherein the first organic functional material A and the second organic functional material B are different,

[0337] - wherein the first organic solvent A and the second organic solvent B are different,

[0338] - and wherein the organic solvent A and the organic solvent B are miscible with each other in any mixing ratio at room temperature,

[0339] Features

[0340] - the solubility of the organic functional material A in the organic solvent A at room temperature is ≥ 20 g / l,

[0341] - the solubility of the organic functional material B in the organic solvent B at room temperature is ≥ 20 g / l, and

[0342] - The solubility of the organic functional material A in the organic solvent B at room temperature is <20 g / l.

[0343] When the two inks of the cartridge are mixed, they produce one ink containing at least a first organic functional material A, at least a second organic functional material B, at least a first organic solvent A and at least a second organic solvent B.

[0344] The present invention also relates to a method for preparing an ink, wherein the ink contains at least a first organic functional material A, a second organic functional material B, at least a first organic solvent A and at least a second organic solvent B, characterized in that the at least two different inks of the box described in the present invention are mixed.

[0345] The invention furthermore relates to an electronic device, preferably an organic light-emitting diode (OLED), characterised in that at least one layer has been produced using the process according to the invention.

[0346] An electronic device is taken to mean a device which comprises an anode, a cathode and at least one functional layer therebetween, wherein the functional layer comprises at least one organic functional material.

[0347] The organic electronic device is preferably an organic light emitting diode (OLED), an organic integrated circuit (O-IC), an organic field effect transistor (O-FET), an organic thin film transistor (O-TFT), an organic light emitting transistor (O-LET), an organic solar cell (O-SC), an organic photovoltaic (OPV) cell, an organic optical detector, an organic photoreceptor, an organic field quenching device (O-FQD), an organic electrical sensor, a light emitting electrochemical cell (LEC) or an organic laser diode (O-laser), more preferably an organic light emitting diode (OLED).

[0348] Surprisingly, it was found that by applying the method of the present application, the components of the different inks are combined only for a short time before they dry. Due to the fact that the time interval between mixing and drying of the ink is significantly shorter than its shelf life, there are no longer any problems regarding the stability of the ink.

[0349] In particular, when, for example, the organic functional material A of the first ink A has low solubility or is insoluble in the at least one organic solvent B of the second ink B, the organic functional material A can be stored and handled in the at least one organic solvent A and combined with the printing-suitable organic solvent B only shortly before drying. Thus, precipitation of the composition in the ink during storage can be prevented.

[0350] Furthermore, as shown above and in the examples, by utilizing the printing method of the present invention, it is possible to produce, for example, a full-color OLED display that does not have the disadvantages of the conventional printing methods described above.

[0351] These aforementioned advantages are not accompanied by a loss of other electronic properties.

[0352] The present invention is explained in more detail below with reference to Examples, but the present invention is not limited thereto.

[0353] Example

[0354] In the examples, the following materials were used.

[0355]

[0356] Example 1

[0357] Long-term ink stability check

[0358] In order to evaluate whether the solvent blends formed in pixels by the present invention were suitable for direct use, a series of inks were prepared and monitored.

[0359] Compound D1 was weighed into a glass vial to allow the preparation of an ink at a concentration of 40 g / l. In a separate container, ENA and menthyl isovalerate were purged with an inert gas (nitrogen) for 20 minutes. ENA was added to the solid using a glass pipette. The solution was stirred at room temperature with a magnetic stirring bar until the solid was completely dissolved, thereby obtaining Solution 1.

[0360] An aliquot of solution 1 was dispensed into another glass vial and menthyl isovalerate was added to give a solution 2 with a concentration of 13.33 g / l and a solvent ratio of menthyl isovalerate / ENA of 2 / 1 (vol / vol).

[0361] An aliquot of solution 1 was dispensed into another glass vial and menthyl isovalerate was added to give a solution 3 with a concentration of 6.67 g / l and a solvent ratio of menthyl isovalerate / ENA of 5 / 1 (vol / vol).

[0362] The clear solutions 1-3 were stored in glass bottles under argon at room temperature for 14 days and checked regularly for precipitation.

[0363] Solution 1 remained transparent throughout the observation period.

[0364] Solution 2 and Solution 3 became turbid after 4 hours and most of the solid material precipitated within 20 hours.

[0365] Solution 1 is long-term stable, but solutions 2 and 3 cannot be stored for long periods of time.

[0366] Example 2

[0367] Short-term ink stability check

[0368] In order to determine the maximum amount of poor solvent to be used in a pixel, a titration experiment was performed.

[0369] Compound D1 was weighed into a glass vial to allow the preparation of an ink at a concentration of 40 g / l. In a separate container, ENA and menthyl isovalerate were purged with an inert gas (nitrogen) for 20 minutes. ENA was added to the solid using a glass pipette. The solution was stirred at room temperature with a magnetic stirring bar until the solid was completely dissolved.

[0370] To an aliquot of this solution, menthyl isovalerate was added dropwise with magnetic stirring and the solution was monitored for immediate precipitation.

[0371] Precipitation was not observed until the solvent ratio of menthyl isovalerate / ENA exceeded 15 / 1 (vol / vol) and the approximate concentration dropped below 2.5 g / l. After a few hours, the solution began to become turbid and a precipitate formed.

[0372] Comparative Example 3

[0373] Use 1 ink and print it into one pixel to prepare the functional layer (i.e.: G-EML)

[0374]

[0375] H1:D1 could not be achieved by printing two materials in menthyl isovalerate.

[0376] Example 3

[0377] Use 2 inks and print them into one pixel to prepare the functional layer (i.e.: G-EML)

[0378]

[0379] H1:D1 can be achieved by printing H1 (menthyl isovalerate) and D1 (ENA).

[0380] Comparative Example 4

[0381] Use one ink and print it into one pixel to prepare the functional layer

[0382]

[0383] Since H2 has a short shelf life in menthyl isovalerate, H1:H2 cannot be achieved by printing both materials in menthyl isovalerate.

[0384] Example 4

[0385] Use 2 inks and print them into one pixel to prepare the functional layer

[0386]

[0387] H1:H2 can be achieved by printing H1 (menthyl isovalerate) and H2 (ENA). After printing H1 (menthyl isovalerate) and H2 (ENA) into the same pixel, the stability of H2 in menthyl isovalerate is not an issue because the ink mixture only remains for a few minutes before drying.

Claims

1. A method for printing a functional layer containing at least two different organic functional materials A and organic functional material B, the method comprising the following steps: (a) providing a substrate, the substrate having at least a first pixel type A, (b) printing a first ink A into the first pixel type A, wherein the first ink A contains at least one organic functional material A and at least one organic solvent A, (c) printing a second ink B into the first pixel type A, wherein the second ink B contains at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at any mixing ratio at room temperature, and (d) then drying the first pixel type A, Features - the solubility of the organic functional material A in the organic solvent A at room temperature is ≥ 20 g / l, - the solubility of the organic functional material B in the organic solvent B at room temperature is ≥ 20 g / l, and - The solubility of the organic functional material A in the organic solvent B at room temperature is <20 g / l.

2. A method for printing two functional layers, wherein the first functional layer contains at least one, preferably one, organic functional material H and the second functional layer contains at least two different organic functional materials A and organic functional material B, the method comprising the following steps: (a) providing a substrate, the substrate having at least a first pixel type A, (b) printing ink H into the first pixel type A, wherein the ink H contains at least one organic functional material H and at least one organic solvent H, (c) then drying the first pixel A, (d) then printing a first ink A into the first pixel type A, the first ink A containing at least one organic functional material A and at least one organic solvent A, and (e) printing a second ink B into the first pixel type A, wherein the second ink B contains at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at any mixing ratio at room temperature, and (f) then drying the first pixel type A, Features The solubility of the organic functional material A in the organic solvent A at room temperature is ≥ 20 g / l, The solubility of the organic functional material B in the organic solvent B at room temperature is ≥ 20 g / l, The solubility of the organic functional material A in the organic solvent B at room temperature is less than 20 g / l, and The solubility of the organic functional material H in the organic solvent A is less than 20 g / l.

3. The method according to claim 1 or 2, characterized in that The solubility of the organic functional material B in the organic solvent A at room temperature is less than 20 g / l.

4. The method according to one or more of claims 1 to 3, characterized in that The solubility of the organic functional material A in the organic solvent A at room temperature is ≥30 g / l, preferably ≥40 g / l.

5. The method according to one or more of claims 1 to 4, characterized in that The solubility of the organic functional material B in the organic solvent B at room temperature is ≥30 g / l, preferably ≥40 g / l.

6. The method according to one or more of claims 1 to 5, characterized in that The solubility of the organic functional material A in the organic solvent B at room temperature is <10 g / l, preferably <5 g / l.

7. The method according to one or more of claims 3 to 5, characterized in that The solubility of the organic functional material B in the organic solvent A at room temperature is <10 g / l, preferably <5 g / l.

8. The method according to one or more of claims 1 to 7, characterized in that In addition to the first ink A and the second ink B, at least a third ink C is printed into the first pixel A, and the third ink C contains at least one organic functional material C different from the organic functional material A and the organic functional material B and at least one organic solvent C different from the organic solvent A and / or the organic solvent B.

9. The method according to one or more of claims 1 to 8, characterized in that The functional layer is a functional layer of an electronic component, preferably a functional layer of an organic light emitting diode (OLED).

10. The method according to claim 9, characterized in that The functional layer is a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL) or an electron injection layer (EIL), preferably an emission layer (EML).

11. The method according to one or more of claims 1 to 10, characterized in that The at least one organic functional material A and / or the at least one organic functional material B is a low molecular weight material having a molecular weight of ≤3.000 g / mol.

12. Method according to one or more of claims 1 to 11, characterised in that The at least one organic functional material A and the at least one organic functional material B are different host materials.

13. The method according to one or more of claims 1 to 11, characterized in that The at least one organic functional material A is a host material and the at least one organic functional material B is a light emitting material.

14. Method according to one or more of claims 1 to 11, characterised in that The at least one organic functional material A and the at least one organic functional material B are different light-emitting materials.

15. The method according to claim 13 or 14, characterized in that The light emitting material is selected from fluorescent light emitting materials and phosphorescent light emitting materials.

16. Method according to one or more of claims 1 to 15, characterised in that Ink A, ink B and optional ink C are printed into the same pixel type to produce an ink containing at least a first organic functional material A, at least a second organic functional material B and optionally at least a third organic functional material C, at least a first organic solvent A, at least a second organic solvent B and optionally at least a third organic solvent C.

17. The method according to one or more of claims 1 to 16, characterized in that Based on the total weight of the ink, the content of the organic functional material A, the organic functional material B and / or the organic functional material C in the corresponding ink is ≥2 wt %, preferably ≥3 wt %, more preferably ≥4 wt %.

18. Method according to one or more of claims 1 to 17, characterised in that The boiling point of the organic solvent A, the organic solvent B and / or the organic solvent C is in the range of 120°C to 400°C, preferably in the range of 200°C to 350°C, more preferably in the range of 225°C to 325°C, most preferably in the range of 250°C to 300°C.

19. The method according to one or more of claims 1 to 18, characterized in that The viscosity of the first ink, the second ink and / or the third ink is respectively 0.8 mPa . s to 50 mPa . s, preferably within 1 mPa . s to 40 mPa . s, more preferably in the range of 2 mPa . s to 15 mPa . within the range of s.

20. The method according to one or more of claims 1 to 19, characterized in that The surface tension of the first ink, the second ink and / or the third ink is respectively in the range of 15 mN / m to 70 mN / m, preferably in the range of 10 mN / m to 50 mN / m, more preferably in the range of 20 mN / m to 40 mN / m.

21. The method according to one or more of claims 1 to 20, characterized in that The printing method is inkjet printing.

22. The method according to one or more of claims 1 to 21, characterized in that The substrate has at least two different pixel types, a first pixel type A and a second pixel type B, and preferably has at least three different pixel types, a first pixel type A, a second pixel type B and a third pixel type C.

23. The method according to claim 22, characterized in that At least one functional layer of pixel type B and / or pixel type C is printed according to the method according to one or more of claims 1 to 20.

24. A method for manufacturing an OLED comprising at least a hole injection layer (HIL), a hole transport layer (HTL) and an emission layer (EML) between a pair of electrodes, characterized in that The light emitting layer (EML) is produced according to the method of one or more of claims 1 to 23.

25. A method for manufacturing a display comprising an OLED, characterized in that The OLED is produced according to the method as claimed in claim 24.

26. The method according to claim 25, characterized in that The display is a full color display.

27. An ink cartridge comprising at least two different inks, ink A and ink B, - wherein the ink A contains at least a first organic functional material A and at least a first organic solvent A, - wherein the ink B contains at least a second organic functional material B and at least a second organic solvent B, - wherein the first organic functional material A and the second organic functional material B are different, - wherein the first organic solvent A and the second organic solvent B are different, - and wherein the organic solvent A and the organic solvent B are miscible with each other in any mixing ratio at room temperature, Features - the solubility of the organic functional material A in the organic solvent A at room temperature is ≥ 20 g / l, - the solubility of the organic functional material B in the organic solvent B at room temperature is ≥ 20 g / l, and - The solubility of the organic functional material A in the organic solvent B at room temperature is <20 g / l.

28. The box according to claim 27, characterized in that The two inks produce one ink containing at least a first organic functional material A, at least a second organic functional material B, at least a first organic solvent A and at least a second organic solvent B when mixed.

29. A method for preparing an ink, the ink comprising at least a first organic functional material A, a second organic functional material B, at least a first organic solvent A and at least a second organic solvent B, Features The at least two different inks of the cartridge according to claim 27 are mixed.

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