Method for manufacturing a substrate with an organic functional film

Abstract

Provided is a method for producing an organic functional film-attached substrate having: a substrate; a partition wall for defining openings on the substrate; and an organic functional film in the partition wall. The method comprises: a step for applying, onto the inside of the partition wall, an organic functional ink containing an organic functional material and a solvent including a low-volatility and high-viscosity solvent through an inkjet method; and a step for removing the solvent from the organic functional ink applied onto the inside of the partition wall through pressure reduction to form an organic functional film, wherein the low-volatility and high-viscosity solvent has a viscosity at 25 °C of 200 mPa·s or more, and when the pressure is reduced from the atmospheric pressure to 140 Pa for one minute while heating the low-volatility and high-viscosity solvent to 150 °C, a residual rate of the low-volatility and high-viscosity solvent is 80 mass% or more and the content of the low-volatility and high-viscosity solvent in said solvent is 2.5 mass% or more. According to this method, the variation in the shape of an organic functional layer due to the difference of ink application timing can be suppressed, and an organic functional film-attached substrate having an organic functional film with excellent flatness can be produced.

Description

[Technical field]

[0001] The present invention relates to a method for producing a substrate with an organic functional film. [Background technology]

[0002] In organic electroluminescence (hereinafter referred to as organic EL) elements, organic functional films made of organic compounds are used as the light-emitting layer and charge injection layer. In particular, the hole injection layer is responsible for the transfer of charges between the anode and the hole transport layer or the light-emitting layer, and plays an important role in achieving low-voltage operation and high brightness of the organic EL element. The methods for forming a hole injection layer are roughly divided into dry processes, such as vapor deposition, and wet processes, such as spin coating, and comparing these processes, wet processes can efficiently manufacture thin films with high flatness over a large area. Therefore, as organic EL displays are currently being made larger, there is a demand for hole injection layers that can be formed by wet processes, and a technology for hole injection layers that can be formed by wet processes has been reported (Patent Document 1).

[0003] In the manufacture of organic EL displays, when a hole injection layer or other organic functional layers are formed by a wet process such as an inkjet method, a partition (bank) is generally provided to surround the region where the layer is to be formed, and an organic functional ink is applied to the opening of the partition. In this case, problems related to the non-uniformity of the organic functional film may occur, which may cause uneven light emission of the resulting organic EL element.

[0004] In addition, in the manufacture of an organic EL display, organic functional inks are successively applied into the openings of the partitions provided on the substrate, and then an organic solvent is removed by heating or reducing pressure, etc., to form an organic functional layer. In this case, since the drying of the ink starts sequentially in the order of application on the substrate, variations occur in the shape of the organic functional layer due to differences in the timing of ink application within a plurality of partition walls (Patent Document 2). This problem becomes more prominent as the substrate used is larger, and with the increasing size of displays in recent years, the demand for technologies to suppress such variations is also increasing further.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing a substrate with an organic functional film having an organic functional film with good flatness, which can suppress variations in the shape of the organic functional layer caused by differences in the timing of ink application.

Means for Solving the Problems

[0007] The technology of Patent Document 2 above solves the above problems by controlling the temperature of the liquid discharged from the inkjet nozzle to make the drying rate of the liquid landing on the substrate approach a uniform state, but it requires a special device and lacks versatility. Therefore, the present inventors have conducted intensive studies from the viewpoints of the volatility and viscosity of the solvent constituting the organic functional ink, and as a result, by using a low-volatility high-viscosity solvent having predetermined volatility characteristics and predetermined viscosity characteristics as the solvent of the organic functional ink, when the ink is applied into the partition walls by inkjet coating, variations in the shape of the organic functional layer caused by differences in the timing of ink application can be suppressed, and an organic functional film with good flatness can be formed. It was found that a substrate with an organic functional film can be produced, and the present invention was completed.

[0008] That is, the present invention is 1. A method for manufacturing a substrate with an organic functional film, comprising a substrate, a partition wall defining an opening on the substrate, and an organic functional film within the partition wall, the method comprising: a step of applying an organic functional ink containing an organic functional material and a solvent containing a low-volatility high-viscosity solvent into the partition wall by an inkjet method; a step of removing the solvent from the organic functional ink applied into the partition wall by reducing the pressure to form an organic functional film; wherein the viscosity of the low-volatility high-viscosity solvent at 25°C is 200 mPa·s or more; when the pressure is reduced from normal pressure to 140 Pa in 1 minute while heating the low-volatility high-viscosity solvent at 150°C, the residual ratio of the low-volatility high-viscosity solvent is 80% by mass or more; A method for manufacturing a substrate with an organic functional film, characterized in that the content of the low-volatility high-viscosity solvent in the solvent is 2.5% by mass or more. 2. The method for manufacturing a substrate with an organic functional film according to 1, wherein the low-volatility high-viscosity Degree of dissolution solvent is a compound represented by the following formula (S1). [Chemical formula] (In the formula, R represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with a hydroxyl group or an alkoxy group having 1 to 10 carbon atoms, and R' represents a divalent hydrocarbon group.) 3. The method for manufacturing a substrate with an organic functional film according to 2, wherein R represents an alkyl group having 1 to 5 carbon atoms which may be substituted with a hydroxyl group, and R' represents an alkylene group having 1 to 5 carbon atoms. 4. The method for manufacturing a substrate with an organic functional film according to any one of 1 to 3, wherein the low-volatility high-viscosity solvent is at least one selected from 2-acetamidoethanol and N-(2-hydroxyethyl)lactamide. 5. The method for manufacturing a substrate with an organic functional film according to any one of 1 to 4, wherein the content of the low-volatility high-viscosity solvent in the solvent is 5.0% by mass or more. 6. The manufacturing method of a substrate with an organic functional film according to any one of 1 to 5, wherein the solvent, as a solvent other than the low-volatility high-viscosity solvent, contains only a solvent having a boiling point of 180 °C or higher, higher volatility and lower viscosity than the low-volatility high-viscosity solvent. 7. The manufacturing method of a substrate with an organic functional film according to 6, wherein the solvent other than the low-volatility high-viscosity solvent contains a hydrophilic glycol-based solvent at a ratio of 15 to 40% by mass. 8. The manufacturing method of a substrate with an organic functional film according to 6, wherein the solvent other than the low-volatility high-viscosity solvent contains a solvent having a surface tension at 25 °C of 40 mN / m or less at a ratio of 30 to 50% by mass. 9. The manufacturing method of a substrate with an organic functional film according to 6, wherein the solvent other than the low-volatility high-viscosity solvent contains a solvent having a viscosity at 25 °C of 10 mPa·s or less at a ratio of 60 to 85% by mass. 10. The manufacturing method of a substrate with an organic functional film according to any one of 1 to 9, wherein the organic functional material is an arylamine derivative or a polythiophene derivative. 11. The manufacturing method of an electronic device including a step of further forming an organic functional layer on a substrate with an organic functional film obtained by any one of the manufacturing methods of 1 to 10. 12. When manufacturing a substrate with an organic functional film having a substrate, a partition wall defining an opening on this substrate, and an organic functional film in this partition wall, an ink for an inkjet method applied by an inkjet method in the partition wall, which contains an organic functional material and a solvent containing a low-volatility high-viscosity solvent, wherein the viscosity of the low-volatility high-viscosity solvent at 25 °C is 200 mPa·s or more, when the pressure is reduced from normal pressure to 140 Pa in 1 minute while heating the low-volatility high-viscosity solvent at 150 °C, the residual ratio of the low-volatility high-viscosity solvent is 80% by mass or more, and the content of the low-volatility high-viscosity solvent in the solvent is 2.5% by mass or more. The ink for an inkjet method is characterized by this. 13. The low-volatility high-vis Degree of dissolution cosity solvent is a compound represented by the following formula (S1) of 12 Ink for inkjet method,

Chemical formula

Advantages of the Invention

[0009] According to the method for manufacturing a substrate with an organic functional film of the present invention, in a plurality of partition walls, variations in the shape of the organic functional layer due to differences in the timing of ink application can be suppressed, and a substrate with an organic functional film having a good flatness can be efficiently produced with an organic functional film. That is, since the ink used in the manufacturing method of the present invention contains a predetermined low-volatility high-viscosity solvent, even if it is left for a certain period of time after coating, the shape of the obtained coating film hardly changes. For example, there is no significant change between the shape of the ink (coating film) applied in the first partition wall and the shape of the ink (coating film) applied in the last partition wall, and a stable organic functional film with good flatness can be produced.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in more detail. In the present invention, the "solid content" regarding the organic functional ink means components other than the solvent contained in the ink. Also, charge transportability is synonymous with conductivity and synonymous with hole transportability. The manufacturing method of a substrate with an organic functional film according to the present invention is a manufacturing method of a substrate with an organic functional film having a substrate, a partition wall defining an opening on this substrate, and an organic functional film within this partition wall, comprising: a step of applying, by an inkjet method, an organic functional ink containing an organic functional material and a solvent containing a low-volatility high-viscosity solvent into the partition wall; and a step of forming an organic functional film by removing the solvent from the organic functional ink applied within the partition wall by reducing the pressure. As the above solvent, one having a content of the low-volatility high-viscosity solvent of 2.5 mass% or more is used, and as the above low-volatility high-viscosity solvent, one having a viscosity at 25°C of 200 mPa·s or more and a residual rate of 80 mass% or more when the pressure is reduced from normal pressure to 140 Pa in 1 minute while heating at 150°C is used, which is characterized in that.

[0011] The present invention uses, as a solvent for an organic functional ink (hereinafter also referred to as an ink solvent), a low-volatility high-viscosity Degree of dissolution solvent containing the solvent at a ratio of 2.5 mass% or more and having a viscosity at 25°C of 200 mPa·s or more and a residual rate of 80 mass% or more when the pressure is reduced from normal pressure to 140 Pa in 1 minute while heating at 150°C. By using such a solvent, within the partition wall, variations in the shape of the organic functional layer due to differences in the timing of ink application can be suppressed, and a substrate with an organic functional film having an organic functional film with good film uniformity (flatness) within the partition wall can be efficiently produced. The above residual rate is not particularly limited as long as it is 80 mass% or more, but considering enhancing the effect of suppressing variations in the shape of the organic functional layer due to differences in the timing of ink application, 85 mass% or more is preferable, and 88 mass% or more is more preferable.

[0012] Specifically, the above residual rate can be obtained, for example, by the following method. Weigh approximately 0.04 g of an organic solvent into an aluminum pan (φ5×5, Cat.No.8579, manufactured by Rigaku Corporation), and weigh the aluminum pan together with the organic solvent (mass Wt(B)). Then, place this aluminum pan on the heater inside a heating and decompression device (for example, Berger type vacuum oven BV-001 type manufactured by Shibata Scientific Technology Co., Ltd.), immediately cover the device with a glass lid, and decompress the inside with a vacuum pump to perform a heating and decompression treatment for 1 minute. At this time, the degree of decompression of the vacuum pump used for decompression is, for example, 1000 Pa after 10 seconds, 450 Pa after 20 seconds, 300 Pa after 30 seconds, 210 Pa after 40 seconds, 150 Pa after 50 seconds, and 140 Pa after 60 seconds. Also, for example, the heater inside the heating and decompression device is set to 150 °C. After the heating and decompression treatment for 1 minute, immediately take out the aluminum pan and allow it to cool, and weigh the aluminum pan together with the organic solvent (mass Wt(A)). Using the mass Wt(B) and mass Wt(A) obtained by the above method, calculate the solvent residual rate (%) according to the formula [mass Wt(A) / mass Wt(B)]×100.

[0013] As described above, the content of the low-volatility and high-viscosity Degree of dissolution medium in the ink solvent is 2.5 mass% or more. From the viewpoint of improving the uniformity of the film in the above partition wall with good reproducibility, 3.0 mass% or more is preferable, 3.5 mass% or more is more preferable, 4.0 mass% or more is even more preferable, 4.5 mass% or more is further preferable, and 5.0 mass% or more is even further preferable. Also, the low-volatility and high-viscosity Degree of dissolution upper limit of the content of the medium in the ink solvent is not particularly limited as long as the uniformity of the film is good. However, considering points such as suppressing the creeping phenomenon of the ink applied in the partition wall, improving the solubility of the organic functional material, improving the wetting spreadability of the ink in the partition wall, and maintaining the ink viscosity within an appropriate range, it is usually 50 mass%, preferably 40 mass%, more preferably 30 mass%, even more preferably 20 mass%, and further preferably 15 mass%.

[0014] Also, the low-volatility and high-viscosity Degree of dissolutionThe viscosity of the medium at 25°C is not particularly limited as long as it is 200 mPa·s or more. However, from the viewpoint of reproducibly enhancing the uniformity of the film within the partition wall, 210 mPa·s or more is preferable, and 220 mPa·s or more is more preferable. The upper limit of the viscosity is not limited as long as it can be adjusted to a viscosity that can be used as the organic functional ink, but 2000 mPa·s or less is preferable.

[0015] The low-volatility high-viscosity Degree of dissolution The medium used in the ink solvent is not particularly limited as long as it is a compound that satisfies the above-mentioned residual ratio characteristics. However, in the present invention, a compound represented by the following formula (S1) is particularly preferable.

[0016] [Chemical formula]

[0017] In formula (S1), R represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with substituents such as a hydroxyl group and an alkoxy group having 1 to 10 carbon atoms, and R' represents a divalent hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with substituents such as a hydroxyl group and an alkoxy group having 1 to 10 carbon atoms. The monovalent hydrocarbon group of R above may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl groups; alkenyl groups having 2 to 10 carbon atoms such as vinyl, n-1-propenyl, n-2-propenyl, 1-methylvinyl, n-1-butenyl, n-2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1-pentenyl, n-1-decenyl groups; aryl groups such as phenyl, tolyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl groups; aralkyl groups such as benzyl, phenylethyl groups and the like.

[0018] In addition, one or more of the hydrogen atoms of these monovalent hydrocarbon groups may be substituted with substituents such as a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms and the like. The alkoxy group having 1 to 10 carbon atoms may be linear, branched or cyclic in the alkyl group therein. Specific examples thereof include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentyloxy, cyclopentyloxy, n-hexyloxy, cyclohexyloxy groups and the like.

[0019] The divalent hydrocarbon group of R' above may be linear, branched or cyclic. Specific examples thereof include alkylene groups such as methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decylene groups; arylene groups such as 1,3-phenylene, 1,4-phenylene, 1,5-naphthylene, 1,6-naphthylene, 1,7-naphthylene, 2,6-naphthylene groups and the like.

[0020] Among these, as R, an alkyl group having 1 to 5 carbon atoms which may be substituted with a hydroxyl group is preferable, an alkyl group having 1 to 3 carbon atoms which may be substituted with a hydroxyl group is more preferable, and a methyl group and a 2-hydroxypropyl group are even more preferable. Further, as R', an alkylene group having 1 to 5 carbon atoms is preferable, an alkylene group having 1 to 3 carbon atoms is more preferable, and a methylene group and an ethylene group are even more preferable. Therefore, as the combination of R and R', a combination in which R is an alkyl group having 1 to 5 carbon atoms which may be substituted with a hydroxyl group and R' is an alkylene group having 1 to 5 carbon atoms is preferable, a combination in which R is an alkyl group having 1 to 3 carbon atoms which may be substituted with a hydroxyl group and R' is an alkylene group having 1 to 3 carbon atoms is more preferable, and a combination in which R is an alkyl group having 1 to 3 carbon atoms which may be substituted with a hydroxyl group and R' is an ethylene group is even more preferable.

[0021] Specific examples of the low-volatility high-viscosity solvent represented by the above formula (S1) that satisfy the above-described characteristics of the residual ratio and the viscosity include 2-acetamidoethanol (viscosity 220 mPa·s), N-(2-hydroxyethyl)lactamide (viscosity 1633 mPa·s), etc., but are not limited thereto. The viscosity in the present invention can be measured, for example, by a TVE-25 type viscometer manufactured by Toki Sangyo Co., Ltd. (hereinafter the same). Note that the low-volatility high-viscosity solvent may be used alone or in combination of two or more as long as the conditions of the content in the above-described solvent are satisfied. Note that the low-volatility high-viscosity solvent may be used alone or in combination of two or more as long as the content rate in the above-described solvent is satisfied.

[0022] The ink solvent used in the present invention is not particularly limited as long as it contains 2.5% by mass or more of the above-described low-volatility high-viscosity solvent. As the remaining (97.5% by mass or less) solvent components (solvent components other than the low-volatility high-viscosity solvent), they can be appropriately selected from the solvents used in organic functional inks. From the viewpoint of suppressing the creeping of the ink in the partition wall with good reproducibility, at atmospheric pressure (1.013×10 5 Pa), it is preferable to use a solvent having a boiling point of 180°C or higher and higher volatility and lower viscosity than the low-volatility high-viscosity solvent.

[0023] Specific examples of such solvents include Hydrophilic glycol solvents such as ethylene glycol (boiling point 197°C), propylene glycol (boiling point 188°C), diethylene glycol (boiling point 244°C), dipropylene glycol (boiling point 232°C), triethylene glycol (boiling point 287°C), tripropylene glycol (boiling point 273°C), hexylene glycol (boiling point 197°C), 1,2-butanediol (boiling point 193°C), 2,3-butanediol (boiling point 182°C), 1,3-butanediol (boiling point 207°C), 1,4-butanediol (boiling point 228°C), 1,5-pentanediol (boiling point 239°C); Glycol monoether solvents such as ethylene glycol monohexyl ether (boiling point 208°C), diethylene glycol monoethyl ether (boiling point 196°C), dipropylene glycol monobutyl ether (boiling point 229°C), diethylene glycol monobutyl ether (boiling point 230°C), diethylene glycol monoisobutyl ether (boiling point 230°C), dipropylene glycol monomethyl ether (boiling point 188°C), diethylene glycol monopropyl ether (propyl carbitol), diethylene glycol monohexyl ether (hexyl carbitol), 2-ethylhexyl carbitol (boiling point 272°C), dipropylene glycol monopropyl ether (boiling point 210°C), tripropylene glycol monomethyl ether (boiling point 243°C), diethylene glycol monomethyl ether (boiling point 193°C), tripropylene glycol monobutyl ether (boiling point 274°C), 2-phenoxyethanol (boiling point 245°C); Glycol diether solvents such as ethylene glycol dibutyl ether (boiling point 202 °C), diethylene glycol diethyl ether (boiling point 188 °C), propylene glycol dibutyl ether, dipropylene glycol methyl-n-propyl ether (boiling point 203 °C), dipropylene glycol diethyl ether (boiling point 221 °C), dipropylene glycol dibutyl ether (boiling point 296 °C), triethylene glycol dimethyl ether (boiling point 216 °C), triethylene glycol butyl methyl ether (boiling point 261 °C), tetraethylene glycol dimethyl ether (boiling point 276 °C); Cyclic carbonate solvents such as ethylene carbonate (boiling point 238 °C) and propylene carbonate (boiling point 242 °C) can be mentioned, and these may be used alone or in combination of two or more.

[0024] In particular, from the viewpoints of ensuring solubility of the organic functional material described later in the ink, improving the uniformity of the film in the partition wall with good reproducibility, suppressing the pile-up phenomenon during banking, etc., the ink solvent used in the present invention preferably contains 15 to 40% by mass of a hydrophilic glycol-based solvent, and more preferably contains 20 to 35% by mass. Examples of this hydrophilic glycol-based solvent include the same glycol-based solvents as those exemplified above, which have a boiling point of 180 °C or higher and are more volatile and less viscous than low-volatility high-viscosity solvents. The pile-up phenomenon is a so-called creeping-up phenomenon in which the ink applied in the opening creeps up the side surface of the partition wall, and the thickness of the peripheral part of the coating film in contact with the side surface of the partition wall becomes thicker than the central part of the coating film.

[0025] Also, from the viewpoint of ensuring the wetting spreadability of the ink in the partition wall, the ink solvent used in the present invention preferably contains 30 to 50% by mass of a solvent having a surface tension of 40 mN / m or less at 25 °C, and more preferably contains 30 to 40% by mass. Specific examples of such solvents include hydrophilic glycol-based solvents such as propylene glycol (surface tension 36.2 mN / m); Ethylene glycol monohexyl ether (surface tension 27.7 mN / m), propylene glycol monobutyl ether (surface tension 26.3 mN / m), diethylene glycol monoethyl ether (surface tension 31.3 mN / m), dipropylene glycol monobutyl ether (surface tension 31.3 mN / m), ethylene glycol monobutyl ether (surface tension 29.1 mN / m), diethylene glycol monobutyl ether (surface tension 30.2 mN / m), diethylene glycol monoisobutyl ether (surface tension 28.4 mN / m), dipropylene glycol monomethyl ether (surface tension 27.9 mN / m), diethylene glycol monopropyl ether (propyl carbitol) (surface tension 29.9 mN / m), diethylene glycol monohexyl ether (hexyl carbitol), 2-ethylhexyl carbitol, dipropylene glycol monopropyl ether (surface tension 27.6 mN / m), tripropylene glycol monomethyl ether (surface tension 30.0 mN / m), diethylene glycol monomethyl ether (surface tension 34.3 mN / m), tripropylene glycol monobutyl ether (surface tension 29.7 mN / m), and other glycol monoether solvents can be mentioned. These can be used alone or in combination of two or more. In addition, in the present invention, the surface tension can be measured, for example, by an automatic surface tension meter CBVP-Z type manufactured by Kyowa Interface Science Co., Ltd. (hereinafter the same).

[0026] Furthermore, from the viewpoint of adjusting the viscosity of the ink within an appropriate range, the ink solvent used in the present invention preferably contains 60 to 85% by mass of a solvent having a viscosity of 10 mPa·s (cP) or less at 25°C, more preferably 60 to 80% by mass, and even more preferably 60 to 70% by mass. Specific examples of such solvents include carbonate solvents such as propylene carbonate (viscosity 2.7 mPa·s); Ethylene glycol monohexyl ether (viscosity 5.2 mPa·s), propylene glycol monobutyl ether (viscosity 2.9 mPa·s), diethylene glycol monoethyl ether (viscosity 3.9 mPa·s), dipropylene glycol monobutyl ether (viscosity 4.9 mPa·s), ethylene glycol monobutyl ether (viscosity 3.1 mPa·s), diethylene glycol monobutyl ether (viscosity 4.8 mPa·s), diethylene glycol monoisobutyl ether (viscosity 5.3 mPa·s), dipropylene glycol monomethyl ether (viscosity 3.6 mPa·s), diethylene glycol monopropyl ether (propyl carbitol), diethylene glycol monohexyl ether (hexyl carbitol), 2-ethylhexyl carbitol, dipropylene glycol monopropyl ether (viscosity 4.0 mPa·s), tripropylene glycol monomethyl ether (viscosity 5.3 cP), diethylene glycol monomethyl ether (viscosity 3.5 mPa·s), tripropylene glycol monobutyl ether (viscosity 6.8 cP), 2-phenoxyethanol (viscosity 20.4 mPa·s), and other glycol monoether solvents can be mentioned, and these may be used alone or in combination of two or more kinds.

[0027] In the ink solvent used in the present invention, it is preferable to use a low-volatility high-viscosity solvent, a hydrophilic glycol-based solvent, a solvent having a surface tension of 40 mN / m or less, and a solvent having a viscosity of 10 mPa·s or less in combination. In this case, the blending ratio of each solvent may be adjusted so that the total is 100% by mass from the content (blending amount) of each solvent described above. However, when a certain solvent contained in the ink solvent is included in a plurality of categories among the four categories of "low-volatility high-viscosity solvent", "hydrophilic glycol-based solvent", "solvent having a surface tension of 40 mN / m or less", and "solvent having a viscosity of 10 mPa·s or less", the said solvent shall be considered as the blending amount of all the solvents included in the categories. For example, when propylene glycol is contained at 10% by mass in the ink solvent, this blending amount constitutes 10% of 15 to 40% by mass of the hydrophilic glycol-based solvent and also constitutes 10% of 30 to 50% by mass of the solvent having a surface tension of 40 mN / m or less.

[0028] As long as the effects of the present invention are not inhibited, the ink solvent used in the present invention may contain, in addition to the various solvents described above, other solvents used as the ink solvent for the purpose of adjusting viscosity, surface tension, etc. Specific examples of other solvents include glycol monoether solvents such as ethylene glycol monopropyl ether (boiling point 151°C), propylene glycol monopropyl ether (boiling point 149°C), propylene glycol monobutyl ether (boiling point 170°C), ethylene glycol monobutyl ether (boiling point 171°C); glycol diether solvents such as ethylene glycol dimethyl ether (boiling point 84°C), ethylene glycol diethyl ether (boiling point 121°C), propylene glycol dimethyl ether (boiling point 97°C), propylene glycol diethyl ether (boiling point 124°C), diethylene glycol dimethyl ether (boiling point 162°C), dipropylene glycol dimethyl ether (boiling point 175°C); cyclic carbonate solvents such as vinylene carbonate (boiling point 162°C); sulfur-containing solvents such as dimethyl sulfoxide and sulfolane; urea solvents such as tetramethylurea and N,N'-dimethylpropyleneurea; amide solvents such as N-methylpyrrolidone, dimethylformamide, and dimethylacetamide; halogenated hydrocarbon solvents such as dichloromethane; ester solvents such as ethyl acetate, n-propyl acetate, n-butyl acetate, ethyl benzoate, methyl benzoate, diethyl fumarate, and butyl benzoate; carbonate solvents such as dimethyl carbonate, ethylene carbonate, and propylene carbonate; nitrile solvents such as acetonitrile, 3-methoxypropionitrile, and 3-ethoxypropionitrile; ketone solvents such as acetone, acetonylacetone, methyl ethyl ketone, methyl isobutyl ketone, methyl isobutenyl ketone, 2-hexanone, 2-pentanone, acetophenone, ethyl phenyl ketone, cyclohexanone, and cyclopentanone; alcohol solvents such as methanol, ethanol, trifluoroethanol, n-propanol, isopropanol, n-butanol, t-butanol, benzyl alcohol, and 2-(benzyloxy)ethanol; ether solvents such as tetrahydrofuran, tetrahydropyran, dioxane, methyl anisole, dimethyl anisole, ethyl anisole, butyl phenyl ether, butyl anisole, pentyl anisole, hexyl anisole, heptyl anisole, octyl anisole, and phenoxytoluene;Examples of the aromatic hydrocarbon solvents include toluene, xylene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, cyclohexylbenzene, tetralin, etc. These may be used alone or in combination of two or more thereof. ; When using other solvents, the total content thereof in the ink solvent is usually less than 10% by mass, and preferably less than 5% by mass from the viewpoint of further enhancing the uniformity of the film within the partition (however, the total of all solvent species used is 100% by mass).

[0029] A preferred composition of the ink solvent used in the present invention includes, but is not limited to, a combination of a low volatility high viscosity solvent, propylene glycol, tripropylene glycol, propylene carbonate, and diethylene glycol mono isobutyl ether. In particular, as the composition of the ink solvent, 2.5 to 15% by mass of a low volatility high viscosity solvent, 5 to 20% by mass of propylene glycol, 10 to 35% by mass of tripropylene glycol, 35 to 70% by mass of propylene carbonate, and 10 to 25% by mass of diethylene glycol mono isobutyl ether (however, the total is 100% by mass, and the total of propylene glycol and tripropylene glycol is 15 to 40% by mass, the total of propylene glycol and diethylene glycol mono isobutyl ether is 30 to 50% by mass, and the total of diethylene glycol mono isobutyl ether and propylene carbonate is 60 to 85% by mass) is preferred. 3 to 10% by mass of a low volatility high viscosity solvent, 10 to 15% by mass of propylene glycol, 15 to 30% by mass of tripropylene glycol, 35 to 60% by mass of propylene carbonate, and 15 to 25% by mass of diethylene glycol mono isobutyl ether (however, the total is 100% by mass, and the total of propylene glycol and tripropylene glycol is 15 to 40% by mass, the total of propylene glycol and diethylene glycol mono isobutyl ether is 30 to 50% by mass, and the total of diethylene glycol mono isobutyl ether and propylene carbonate is 60 to 85% by mass) is more preferred. At least one of 2 - acetamidoethanol and N-(hydroxyethyl)lactamide: 5 to 10% by mass, propylene glycol: 10 to 15% by mass, tripropylene glycol: 15 to 25% by mass, propylene carbonate: 35 to 55% by mass, diethylene glycol monoisobutyl ether: 15 to 25% by mass (however, the total is 100% by mass, and the total of propylene glycol and tripropylene glycol is 15 to 40% by mass, the total of propylene glycol and diethylene glycol monoisobutyl ether is 30 to 50% by mass, and the total of diethylene glycol monoisobutyl ether and propylene carbonate is 60 to 85% by mass) is even more preferable.

[0030] In the present invention, from the viewpoint of suppressing the variation in the shape of the organic functional layer due to the difference in the timing of ink application and obtaining a substrate with an organic functional film having good flatness and good reproducibility, it is preferable that the ink solvent does not contain water as a solvent, but the presence of trace amounts of water contained in the organic solvent used or water contained in the solid content is not necessarily denied.

[0031] As described above, since the present invention is characterized by using an ink solvent containing a low - volatility high - viscosity solvent in a predetermined ratio, for the organic functional material, the substrate with partitions on which the organic functional material is coated, the inkjet device, etc., they can be appropriately selected and used from various materials and various devices. The organic functional material may be any material used as a functional material for electronic elements, and specific examples thereof include charge - transporting substances.

[0032] The charge - transporting substance is not particularly limited, and for example, it can be appropriately selected and used from charge - transporting compounds, charge - transporting oligomers, charge - transporting polymers, etc. used in the field of organic EL, etc. Specific examples thereof include arylamine derivatives such as oligoaniline derivatives, N,N'-diarylbenzidine derivatives, N,N,N',N'-tetraarylbenzidine derivatives; thiophene derivatives such as oligothiophene derivatives, thienothiophene derivatives, thienobenzothiophene derivatives; various charge transporting compounds such as pyrrole derivatives such as oligopyrrole, charge transporting oligomers, polythiophene derivatives, polyaniline derivatives, polypyrrole derivatives, etc. Among these, polythiophene derivatives and arylamine derivatives are preferred.

[0033] In addition, for example, charge transporting compounds (low molecular weight compounds) or charge transporting oligomers such as tertiary arylamine compounds represented by formula (A1) or (A2) described later are preferably monodisperse (i.e., the molecular weight distribution is 1) from the viewpoint of producing a thin film with high flatness. In this case, the molecular weight of the charge transporting substance is usually about 200 to 9,000 from the viewpoint of preparing a uniform ink that gives a thin film with high flatness. However, from the viewpoint of obtaining a thin film with more excellent charge transport properties, 300 or more is preferred, 400 or more is more preferred, and from the viewpoint of preparing a uniform ink that gives a thin film with high flatness with better reproducibility, 8,000 or less is preferred, 7,000 or less is more preferred, 6,000 or less is even more preferred, and 5,000 or less is further preferred.

[0034] Examples of the charge transporting substance include those disclosed in JP-A-2002-151272, WO 2004 / 105446, WO 2005 / 043962, WO 2008 / 032617, WO 2008 / 032616, WO 2013 / 042623, WO 2014 / 141998, WO 2014 / 185208, WO 2015 / 050253, WO 2015 / 137391, WO 2015 / 137395, WO 2015 / 146912, WO 2015 / 146965, WO 2016 / 190326, WO 2016 / 136544, WO 2016 / 204079, etc.

[0035] In a preferred embodiment, the charge transporting material is a polythiophene derivative containing a repeating unit represented by formula (1) or an amine adduct thereof.

[0036]

Chemical formula

[0037] In the formula, R 1 and R 2 are each independently a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, -O-[Z-O] h -R e or a sulfonic acid group, or R 1 and R 2 together form -O-Y-O-, where Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and may be substituted with a sulfonic acid group, Z is an alkylene group having 1 to 40 carbon atoms which may be substituted with a halogen atom, p is an integer of 1 or more, and R e is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0038] The alkyl group having 1 to 40 carbon atoms may be linear, branched or cyclic. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosanyl, behenyl, triacontyl, tetracosanyl groups and the like. In the present invention, an alkyl group having 1 to 18 carbon atoms is preferred, and an alkyl group having 1 to 8 carbon atoms is more preferred.

[0039] Examples of the fluoroalkyl group having 1 to 40 carbon atoms are not particularly limited as long as it is an alkyl group having 1 to 40 carbon atoms in which at least one hydrogen atom on the carbon atom is substituted with a fluorine atom. Specific examples thereof include fluoromethyl, difluoromethyl, perfluoromethyl, 1-fluoroethyl, 2-fluoroethyl, 1,2-difluoroethyl, 1,1-difluoroethyl, 2,2-difluoroethyl, 1,1,2-trifluoroethyl, 1,2,2-trifluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, 1,2,2,2-tetrafluoroethyl, perfluoroethyl, 1-fluoropropyl, 2-fluoropropyl, 3-fluoropropyl, 1,1-difluoropropyl, 1,2-difluoropropyl, 1,3-difluoropropyl, 2,2-difluoropropyl, 2,3-difluoropropyl, 3,3-difluoropropyl, 1,1,2-trifluoropropyl, 1,1,3-trifluoropropyl, 1,2,3-trifluoropropyl, 1,3,3-trifluoropropyl, 2,2,3-trifluoropropyl, 2,3,3-trifluoropropyl, 3,3,3-trifluoropropyl, 1,1,2,2-tetrafluoropropyl, 1,1,2,3-tetrafluoropropyl, 1,2,2,3-tetrafluoropropyl, 1,3,3,3-tetrafluoropropyl, 2,2,3,3-tetrafluoropropyl, 2,3,3,3-tetrafluoropropyl, 1,1,2,2,3-pentafluoropropyl, 1,2,2,3,3-pentafluoropropyl, 1,1,3,3,3-pentafluoropropyl, 1,2,3,3,3-pentafluoropropyl, 2,2,3,3,3-pentafluoropropyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl, perfluorooctyl group, and the like.

[0040] As the alkoxy group having 1 to 40 carbon atoms, the alkyl group therein may be linear, branched or cyclic, and specific examples thereof include methoxy, ethoxy, n-propoxy, i-propoxy, c-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, n-hexoxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy, n-tridecyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, n-nonadecyloxy, n-eicosanyloxy groups.

[0041] The fluoroalkoxy groups having 1 to 40 carbon atoms are not particularly limited as long as they are alkoxy groups having 1 to 40 carbon atoms in which at least one hydrogen atom on the carbon atom is substituted with a fluorine atom. Specific examples thereof include fluoromethoxy, difluoromethoxy, perfluoromethoxy, 1-fluoroethoxy, 2-fluoroethoxy, 1,2-difluoroethoxy, 1,1-difluoroethoxy, 2,2-difluoroethoxy, 1,1,2-trifluoroethoxy, 1,2,2-trifluoroethoxy, 2,2,2-trifluoroethoxy, 1,1,2,2-tetrafluoroethoxy, 1,2,2,2-tetrafluoroethoxy, perfluoroethoxy, 1-fluoropropoxy, 2-fluoropropoxy, 3-fluoropropoxy, 1,1-difluoropropoxy, 1,2-difluoropropoxy, 1,3-difluoropropoxy, 2,2-difluoropropoxy, 2,3-difluoropropoxy, 3,3-difluoropropoxy, 1,1,2-trifluoropropoxy, 1,1,3-trifluoropropoxy, 1,2,3-trifluoropropoxy, 1,3,3-trifluoropropoxy, 2,2,3-trifluoropropoxy, 2,3,3-trifluoropropoxy, 3,3,3-trifluoropropoxy, 1,1,2,2-tetrafluoropropoxy, 1,1,2,3-tetrafluoropropoxy, 1,2,2,3-tetrafluoropropoxy, 1,3,3,3-tetrafluoropropoxy, 2,2,3,3-tetrafluoropropoxy, 2,3,3,3-tetrafluoropropoxy, 1,1,2,2,3-pentafluoropropoxy, 1,2,2,3,3-pentafluoropropoxy, 1,1,3,3,3-pentafluoropropoxy, 1,2,3,3,3-pentafluoropropoxy, 2,2,3,3,3-pentafluoropropoxy, perfluoropropoxy group, and the like.

[0042] As the alkylene group having 1 to 40 carbon atoms, any of linear, branched, and cyclic groups may be used. Specific examples thereof include methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecylene, octadecylene, nonadecylene, eicosanylene group and the like.

[0043] Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, tolyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl group and the like, and phenyl group, tolyl group, and naphthyl group are preferred. Specific examples of the aryloxy group having 6 to 20 carbon atoms include phenoxy, anthracenoxy, naphthoxy, phenanthrenoxy, fluorenoxy group and the like. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom and the like.

[0044] In the above formula (1), R 1 and R 2 are each independently a hydrogen atom, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, -O[C(R a R b )-C(R c R d )-O] h -R e , -OR f , or a sulfonic acid group, or -O-Y-O- formed by the combination of R 1 and R 2 is preferred. R a to R d each independently represent a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and specific examples of these groups are the same as those listed above. Among them, R a ~R d is each independently preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group. R e is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group, preferably a hydrogen atom, a methyl group, a propyl group, or a butyl group. h is preferably 1 to 5, more preferably 1, 2, or 3.

[0045] R f is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group, more preferably -CH2CF3.

[0046] The above R 1 is preferably a hydrogen atom or a sulfonic acid group, more preferably a sulfonic acid group, and R 2 is preferably an alkoxy group having 1 to 40 carbon atoms or -O-[Z-O] h -R e , more preferably -O[C(R a R b )-C(R c R d )-O] h -R e or -OR f , even more preferably -O[C(R a R b )-C(R c R d )-O] h -R e , -O-CH2CH2-O-CH2CH2-O-CH3, -O-CH2CH2-O-CH2CH2-OH, or -O-CH2CH2-OH, or -O-Y-O- formed by R 1 and R 2 being bonded to each other.

[0047] For example, in the above polythiophene derivative according to a preferred embodiment of the present invention, R 1 is a sulfonic acid group, and R 2 contains a repeating unit other than a sulfonic acid group, or R 1 and R 2 contains a repeating unit which is -O-Y-O- formed by their bonding. Preferably, in the above polythiophene derivative, R 1 is a sulfonic acid group, and R 2 contains a repeating unit which is an alkoxy group having 1 to 40 carbon atoms or -O-[Z-O] h -R e or R 1 and R 2 contains a repeating unit which is -O-Y-O- formed by their bonding. More preferably, in the above polythiophene derivative, R 1 is a sulfonic acid group, and R 2 is -O[C(R a R b )-C(R c R d )-O] h -R e or -OR f and contains a repeating unit. Even more preferably, in the above polythiophene derivative, R 1 is a sulfonic acid group, and R 2 is -O[C(R a R b )-C(R c R d )-O] h -R e and contains a repeating unit, or R 1 and R 2 contains a repeating unit which is -O-Y-O- formed by their bonding. Even more preferably, in the above polythiophene derivative, R 1 is a sulfonic acid group, and R 2 is -O-CH2CH2-O-CH2CH2-O-CH3, -O-CH2CH2-O-CH2CH2-OH, or -O-CH2CH2-OH and contains a repeating unit, or R 1and R 2 are bonded to each other and contain a repeating unit which is a group represented by the following formulas (Y1) and (Y2).

[0048] [Chemical formula]

[0049] Preferred specific examples of the above polythiophene derivative include, for example, polythiophene containing at least one kind of repeating unit represented by the following formulas (1-1) to (1-5).

[0050] [Chemical formula]

[0051] In addition, preferred structures of the above polythiophene derivative include, for example, a polythiophene derivative having a structure represented by the following formula (1a). In the following formula, each unit may be bonded randomly or as a block polymer.

[0052] [Chemical formula]

[0053] In the formula, a to d represent the molar ratio of each unit, and satisfy 0 ≤ a ≤ 1, 0 ≤ b ≤ 1, 0 < a + b ≤ 1, 0 ≤ c < 1, 0 ≤ d < 1, and a + b + c + d = 1.

[0054] Furthermore, the above polythiophene derivative may be a homopolymer or a copolymer (including statistical, random, gradient, and block copolymers). As a polymer containing monomer A and monomer B, the block copolymer is, for example, an A-B diblock copolymer, an A-B-A triblock copolymer, and (AB) k- It contains a multi-block copolymer. The polythiophene may contain repeating units derived from other types of monomers (e.g., thienothiophene, selenophene, pyrrole, furan, tellurophene, aniline, arylamine, and arylene (e.g., phenylene, phenylene vinylene, and fluorene, etc.)).

[0055] The content of the repeating unit represented by formula (1) in the above polythiophene derivative is preferably more than 50 mol%, more preferably 80 mol% or more, still more preferably 90 mol% or more, even more preferably 95 mol% or more, and most preferably 100 mol% among all the repeating units contained in the polythiophene derivative.

[0056] The above polythiophene derivative may contain repeating units derived from impurities depending on the purity of the starting monomers used in the polymerization. The term "homopolymer" as described above means a polymer containing repeating units derived from one type of monomer, but it may also contain repeating units derived from impurities. The above polythiophene derivative is preferably a polymer in which basically all the repeating units are the repeating units represented by the above formula (1), and more preferably a polymer containing at least one of the repeating units represented by the above formulas (1-1) to (1-5).

[0057] When the above polythiophene derivative contains a repeating unit having a sulfonic acid group, from the viewpoint of further improving the solubility and dispersibility in an organic solvent, the polythiophene derivative is preferably an amine adduct in which an amine compound is added to at least a part of the sulfonic acid groups contained therein.

[0058] As amine compounds that can be used for the formation of amine adducts, there are monoalkylamine compounds such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, s-butylamine, t-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-ethylhexylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-nonadecylamine, n-eicosanyl amine, etc.; primary amine compounds such as monoarylamine compounds such as aniline, toluidine, 1-naphthylamine, 2-naphthylamine, 1-anthrylamine, 2-anthrylamine, 9-anthrylamine, 1-phenanthrylamine, 2-phenanthrylamine, 3-phenanthrylamine, 4-phenanthrylamine, 9-phenanthrylamine, etc.; dialkylamine compounds such as N-ethylmethylamine, N-methyl-n-propylamine, N-methylisopropylamine, N-methyl-n-butylamine, N-methyl-s-butylamine, N-methyl-t-butylamine, N-methylisobutylamine, diethylamine, N-ethyl-n-propylamine, N-ethylisopropylamine, N-ethyl-n-butylamine, N-ethyl-s-butylamine, N-ethyl-t-butylamine, dipropylamine, N-n-propylisopropylamine, N-n-propyl-n-butylamine, N-n-propyl-s-butylamine, diisopropylamine, N-n-butylisopropylamine, N-t-butylisopropylamine, di(n-butyl)amine, di(s-butyl)amine, diisobutylamine, aziridine (ethyleneimine), 2-methylaziridine (propyleneimine), 2,2-dimethylaziridine, azetidine (trimethyleneimine), 2-methylazetidine, pyrrolidine, 2-methylpyrrolidine, 3-methylpyrrolidine, 2,5-dimethylpyrrolidine, piperidine, 2,6-dimethylpiperidine, 3,5-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, hexamethyleneimine, heptamethyleneimine, octamethyleneimine, etc.Diarylamine compounds such as diphenylamine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, 1,1'-dinaphthylamine, 2,2'-dinaphthylamine, 1,2'-dinaphthylamine, carbazole, 7H-benzo[c]carbazole, 11H-benzo[a]carbazole, 7H-dibenzo[c,g]carbazole, 13H-dibenzo[a,i]carbazole; Secondary amine compounds such as alkylarylamine compounds such as N-methylaniline, N-ethylaniline, N-n-propylaniline, N-isopropylaniline, N-n-butylaniline, N-s-butylaniline, N-isobutylaniline, N-methyl-1-naphthylamine, N-ethyl-1-naphthylamine, N-n-propyl-1-naphthylamine, indoline, isoindoline, 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroisoquinoline; Trialkylamine compounds such as N,N-dimethylethylamine, N,N-dimethyl-n-propylamine, N,N-dimethylisopropylamine, N,N-dimethyl-n-butylamine, N,N-dimethyl-s-butylamine, N,N-dimethyl-t-butylamine, N,N-dimethylisobutylamine, N,N-diethylmethylamine, N-methyldi(n-propyl)amine, N-methyldiisopropylamine, N-methyldi(n-butyl)amine, N-methyldiisobutylamine, triethylamine, N,N-diethyl-n-butylamine, N,N-diisopropylethylamine, N,N-di(n-butyl)ethylamine, tri(n-propyl)amine, tri(i-propyl)amine, tri(n-butyl)amine, tri(i-butyl)amine, 1-methylazetidine, 1-methylpyrrolidine, 1-methylpiperidine; Triarylamine compounds such as triphenylamine; Alkyldiarylamine compounds such as N-methyldiphenylamine, N-ethyldiphenylamine, 9-methylcarbazole, 9-ethylcarbazole;Examples of the tertiary amine compound include dialkylarylamine compounds such as N,N - diethylaniline, N,N - di(n - propyl)aniline, N,N - di(i - propyl)aniline, N,N - di(n - butyl)aniline, etc. Considering the balance of the solubility of the amine adduct, the charge transport property of the obtained organic functional film, etc., the tertiary amine compound is preferred, the trialkylamine compound is more preferred, and triethylamine is even more preferred.; The amine adduct can be obtained by adding a polythiophene derivative to the amine itself or its solution and stirring well.

[0059] Also, the above - mentioned polythiophene derivative or its amine adduct may be one treated with a reducing agent. In the polythiophene derivative or its amine adduct, in a part of the repeating units constituting them, the chemical structure may be an oxidized structure called a "quinoid structure". The term "quinoid structure" is used in contrast to the term "benzenoid structure". For the latter which is a structure containing an aromatic ring, the former means a structure in which the double bond in the aromatic ring moves outside the ring (as a result, the aromatic ring disappears), and two exocyclic double bonds conjugated with the other double bonds remaining in the ring are formed. For those skilled in the art, the relationship between these two structures can be easily understood from the relationship between the structures of benzoquinone and hydroquinone. The quinoid structure for the repeating units of various conjugated polymers is well - known to those skilled in the art. As an example, the quinoid structure corresponding to the repeating unit of the polythiophene derivative containing the repeating unit represented by the above formula (1) is shown in the following formula (1').

[0060] [Chemical formula] (In the formula, R 1 and R 2 are as defined in the above formula (1).)

[0061] This quinoid structure is formed by a process in which a polythiophene derivative containing a repeating unit represented by the above formula (1) undergoes an oxidation reaction by a dopant, that is, a so-called doping reaction, and is part of a structure called a "polaron structure" and a "bipolaron structure" that imparts charge transport properties to the polythiophene derivative. These structures are well-known. In the production of an organic EL device, the introduction of a "polaron structure" and / or a "bipolaron structure" is essential. In fact, when firing a thin film formed from a charge transport varnish (organic functional ink) during the production of an organic EL device, this is achieved by intentionally causing the above doping reaction. The reason why the polythiophene derivative contains a quinoid structure before causing this doping reaction is considered to be that the polythiophene derivative undergoes an unintended oxidation reaction equivalent to the doping reaction during its production process (especially the sulfonation step therein).

[0062] There is a correlation between the amount of the quinoid structure contained in the above polythiophene derivative and the solubility and dispersibility of the polythiophene derivative in an organic solvent. As the amount of the quinoid structure increases, its solubility and dispersibility tend to decrease. For this reason, the introduction of a quinoid structure after the formation of a thin film from a charge transport varnish (organic functional ink) does not cause problems. However, if an excessive amount of the quinoid structure is introduced into the polythiophene derivative due to the above unintended oxidation reaction, it may hinder the production of the charge transport varnish (organic functional ink). In polythiophene derivatives, it is known that there are variations in solubility and dispersibility in an organic solvent. One of the reasons is considered to be that the amount of the quinoid structure introduced into the polythiophene by the above unintended oxidation reaction varies depending on the differences in the production conditions of each polythiophene derivative. Therefore, when the above polythiophene derivative is subjected to a reduction treatment using a reducing agent, even if an excessive amount of the quinoid structure is introduced into the polythiophene derivative, the quinoid structure decreases due to reduction, and the solubility and dispersibility of the polythiophene derivative in an organic solvent improve. As a result, it becomes possible to stably produce a charge transport varnish (organic functional ink) that gives a thin film with excellent homogeneity.

[0063] The conditions for the reduction treatment are not particularly limited as long as they can reduce the quinoid structure to a non-oxidized structure, that is, appropriately convert it to the above-mentioned benzenoid structure (for example, in a polythiophene derivative containing the repeating unit represented by the above formula (1), convert the quinoid structure represented by the above formula (1’) to the structure represented by the above formula (1)). However, for example, this treatment can be carried out by simply bringing the polythiophene derivative or amine adduct into contact with a reducing agent in the presence or absence of a suitable solvent. Such a reducing agent is not particularly limited as long as the reduction is appropriately carried out. For example, aqueous ammonia, hydrazine, etc., which are easily available as commercial products, are suitable. Also, the amount of the reducing agent varies depending on the amount of the reducing agent used and thus cannot be generally defined. However, from the viewpoint of appropriately carrying out the reduction, it is usually 0.1 part by mass or more with respect to 100 parts by mass of the polythiophene derivative or amine adduct to be treated, and from the viewpoint of preventing the remaining of an excessive reducing agent, it is 10 parts by mass or less.

[0064] As an example of a specific method of the reduction treatment, the polythiophene derivative or amine adduct is stirred overnight at room temperature in 28% aqueous ammonia. By carrying out the reduction treatment under such relatively mild conditions, the solubility and dispersibility of the polythiophene derivative or amine adduct in an organic solvent are sufficiently improved.

[0065] In the organic functional ink used in the present invention, when using an amine adduct of a polythiophene derivative, the above reduction treatment may be carried out before or after forming the amine adduct.

[0066] Note that as a result of the reduction treatment, the solubility and dispersibility of the polythiophene derivative or its amine adduct in the solvent change. As a result, the polythiophene derivative or its amine adduct that was not dissolved in the reaction system at the start of the treatment may be dissolved at the end of the treatment. In such a case, an organic solvent that is immiscible with the polythiophene derivative or its amine adduct (in the case of sulfonated polythiophene, acetone, isopropyl alcohol, etc.) is added to the reaction system to cause precipitation of the polythiophene derivative or its amine adduct, and the polythiophene derivative or its amine adduct can be recovered by a method such as filtration.

[0067] The weight average molecular weight of the polythiophene derivative or its amine adduct containing the repeating unit represented by formula (1) is preferably about 1,000 to 1,000,000, more preferably about 5,000 to 100,000, and even more preferably about 10,000 to about 50,000. By setting the weight average molecular weight to be not less than the lower limit, good conductivity can be obtained with good reproducibility, and by setting it to be not more than the upper limit, the solubility in the solvent is improved. The weight average molecular weight is a polystyrene conversion value determined by gel permeation chromatography.

[0068] The polythiophene derivative or its amine adduct contained in the organic functional ink used in the present invention may be only one kind of the polythiophene derivative or its amine adduct containing the repeating unit represented by formula (1), or may be two or more kinds. In addition, as the polythiophene derivative containing the repeating unit represented by formula (1), a commercially available product or a product polymerized by a known method using a thiophene derivative or the like as a starting material may be used, but in any case, it is preferable to use a product purified by a method such as reprecipitation or ion exchange. By using a purified product, the characteristics of the organic EL element provided with the thin film obtained from the organic functional ink used in the present invention can be further enhanced.

[0069] Note that the sulfonation of conjugated polymers and sulfonated conjugated polymers (including sulfonated polythiophene) are described in U.S. Patent No. 8,017,241 to Seshadri et al. Further, sulfonated polythiophene is described in International Publication No. 2008 / 073149 and International Publication No. 2016 / 171935.

[0070] Note that at least a part of the polythiophene derivative containing the repeating unit represented by the above formula (1) or its amine adduct is dissolved in the above-described ink solvent.

[0071] In the present invention, when using a polythiophene derivative containing the repeating unit represented by the formula (1) or its amine adduct, as the charge transporting material, the polythiophene derivative or its amine adduct and other charge transporting compounds may be used in combination, but it is preferably composed only of the polythiophene derivative containing the repeating unit represented by the formula (1) or its amine adduct.

[0072] When using a polythiophene derivative containing the repeating unit represented by the formula (1) or its amine adduct, the content of the charge transporting material in the charge transporting varnish (organic functional ink) is usually appropriately determined in the range of 0.05 to 40% by mass, preferably 0.1 to 35% by mass in the solid content, taking into account the desired film thickness, the viscosity of the varnish (ink), etc.

[0073] A preferred other aspect of the charge transporting material includes a tertiary arylamine compound having at least one nitrogen atom and all nitrogen atoms having a tertiary arylamine structure. That is, this tertiary arylamine compound has at least one nitrogen atom and a structure in which three aromatic groups are bonded to all nitrogen atoms. In the above tertiary arylamine compound, it is preferable that there are two or more nitrogen atoms.

[0074] Preferable examples of the tertiary arylamine compound include compounds represented by the following formula (A1) or (A2).

[0075]

Chem.

[0076] In formula (A2), R 1’ and R 2’ are each independently a hydrogen atom, a halogen atom, a nitro group or a cyano group, or an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with a halogen atom.

[0077] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. The alkyl group having 1 to 20 carbon atoms may be linear, branched or cyclic. Specific examples thereof include linear or branched alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl groups; and cyclic alkyl groups having 3 to 20 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl groups.

[0078] The alkenyl group having 2 to 20 carbon atoms may be linear, branched or cyclic. Specific examples thereof include vinyl, n-1-propenyl, n-2-propenyl, 1-methylvinyl, n-1-butenyl, n-2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1-pentenyl, n-1-decenyl, n-1-eicosenyl groups and the like.

[0079] The alkynyl groups having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include ethynyl, n-1-propynyl, n-2-propynyl, n-1-butynyl, n-2-butynyl, n-3-butynyl, 1-methyl-2-propynyl, n-1-pentynyl, n-2-pentynyl, n-3-pentynyl, n-4-pentynyl, 1-methyl-n-butynyl, 2-methyl-n-butynyl, 3-methyl-n-butynyl, 1,1-dimethyl-n-propynyl, n-1-hexynyl, n-1-decynyl, n-1-pentadecynyl, n-1-eicosynyl groups and the like.

[0080] Examples of the aryl groups having 6 to 20 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl groups and the like. Examples of the heteroaryl groups having 2 to 20 carbon atoms include 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl, 2-imidazolyl, 4-imidazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl groups and the like.

[0081] Among these, R 1’ and R 2’ are preferably a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 20 carbon atoms which may be substituted with a halogen atom, an aryl group having 6 to 20 carbon atoms which may be substituted with a halogen atom, or a heteroaryl group having 2 to 20 carbon atoms which may be substituted with a halogen atom, more preferably a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, or a phenyl group which may be substituted with a halogen atom, still more preferably a hydrogen atom or a fluorine atom, and most preferably a hydrogen atom.

[0082] In formulas (A1) and (A2), Ph 1 is a group represented by formula (P1).

[0083] [Chemical formula]

[0084] In formula (P1), the dashed line is a bond. R 3 ~R 6 are each independently a hydrogen atom, a halogen atom, a nitro group or a cyano group, or an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with a halogen atom. Specific examples thereof include those described in the description of R 1’ and R 2’ .

[0085] In particular, R 3 ~R 6 are preferably a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 20 carbon atoms which may be substituted with a halogen atom, an aryl group having 6 to 20 carbon atoms which may be substituted with a halogen atom, or a heteroaryl group having 2 to 20 carbon atoms which may be substituted with a halogen atom, more preferably a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, or a phenyl group which may be substituted with a halogen atom, still more preferably a hydrogen atom or a fluorine atom, and most preferably a hydrogen atom.

[0086] Ph 1 Preferred groups for include, but are not limited to, the 1,4-phenylene group.

[0087] In formula (A1), Ar 1 are each independently a group represented by any one of the following formulas (Ar1-1) to (Ar1-11), and particularly preferably a group represented by any one of the following formulas (Ar1-1') to (Ar1-11').

[0088]

Chem.

[0089]

Chem.

[0090] In formulas (Ar1-1) to (Ar1-11) and formulas (Ar1-1') to (Ar1-11'), the dashed lines represent bonds. R 7 ~R 27 、R 30 ~R 51 and R 53 ~R 154 are each independently a hydrogen atom, a halogen atom, a nitro group or a cyano group, or a diphenylamino group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with a halogen atom. R 28 and R 29 are each independently an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with Z 1 . R 52 is an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with Z 1 .

[0091] Z 1 is a halogen atom, a nitro group or a cyano group, or an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z 2 . Z 2 is a halogen atom, a nitro group or a cyano group, or an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with Z 3 . Z 3 is a halogen atom, a nitro group or a cyano group.

[0092] In particular, R 7 ~R 27 、R 30 ~R 51 and R 53 ~R 154 are preferably a hydrogen atom, a fluorine atom, a cyano group, a diphenylamino group optionally substituted with a halogen atom, an alkyl group having 1 to 20 carbon atoms optionally substituted with a halogen atom, an aryl group having 6 to 20 carbon atoms optionally substituted with a halogen atom, or a heteroaryl group having 2 to 20 carbon atoms optionally substituted with a halogen atom, more preferably a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 10 carbon atoms optionally substituted with a halogen atom, or a phenyl group optionally substituted with a halogen atom, still more preferably a hydrogen atom or a fluorine atom, and most preferably a hydrogen atom.

[0093] R 28 and R 29 are preferably an aryl group having 6 to 14 carbon atoms optionally substituted with a halogen atom, or a heteroaryl group having 2 to 14 carbon atoms optionally substituted with a halogen atom, more preferably a phenyl group optionally substituted with a halogen atom, or a naphthyl group optionally substituted with a halogen atom, still more preferably a phenyl group optionally substituted with a halogen atom, and even more preferably a phenyl group.

[0094] R 52 is preferably a hydrogen atom, an aryl group having 6 to 20 carbon atoms optionally substituted with Z 1 , more preferably a hydrogen atom, a phenyl group optionally substituted with Z 1 , or a naphthyl group optionally substituted with Z 1 , still more preferably a phenyl group optionally substituted with Z 1 , and even more preferably a phenyl group.

[0095] In formulas (Ar1-10), (Ar1-11), (Ar1-10') and (Ar1-11'), Ar 4is, independently of each other, an aryl group having 6 to 20 carbon atoms which may be substituted with a diarylamino group in which each aryl group is an aryl group having 6 to 20 carbon atoms. Specific examples of the aryl group having 6 to 20 carbon atoms are the same as those described for R 1’ and R 2’ above. Specific examples of the diarylamino group include a diphenylamino group, a 1-naphthylphenylamino group, a di(1-naphthyl)amino group, a 1-naphthyl-2-naphthylamino group, a di(2-naphthyl)amino group, and the like.

[0096] Ar 4 is preferably phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, p-(diphenylamino)phenyl, p-(1-naphthylphenylamino)phenyl, p-(di(1-naphthyl)amino)phenyl group, p-(1-naphthyl-2-naphthylamino)phenyl, p-[di(2-naphthyl)amino]phenyl group, etc., and more preferably p-(diphenylamino)phenyl group.

[0097] In formula (A1), Ar 2 is, independently of each other, a group represented by any of formulas (Ar2-1) to (Ar2-18), and particularly preferably a group represented by any of formulas (Ar2-1'-1) to (Ar2-18'-2). In the following formulas, Ar 4 represents the same meaning as above, DPA is a diphenylamino group, and the dashed line is a bond.

[0098]

Chemical formula

[0099]

Chemical formula

[0100] In formulas (Ar2-16), (Ar2-16'-1), and (Ar2-16'-2), R 155 is a hydrogen atom, an aryl group having 6 to 14 carbon atoms which may be substituted with Z 1 , or a heteroaryl group having 2 to 14 carbon atoms which may be substituted with Z 1 . Examples of the aryl group and the heteroaryl group include those similar to those described in the description of R 1’ and R 2’ . Among these, as R 155 , a hydrogen atom, a phenyl group which may be substituted with Z 1 , a 1-naphthyl group which may be substituted with Z 1 , a 2-naphthyl group which may be substituted with Z 1 , a 2-pyridyl group which may be substituted with Z 1 , a 3-pyridyl group which may be substituted with a phenyl group which may be substituted with Z 1 , or a 4-pyridyl group which may be substituted with Z 1 is preferable, a phenyl group which may be substituted with Z 1 is more preferable, and a phenyl group or a (2,3,5,6-tetrafluoro-4-(trifluoromethyl)phenyl) group is even more preferable.

[0101] In formulas (Ar2-17), (Ar2-17'-1), and (Ar2-17'-2), R 156 and R 157 are an aryl group having 6 to 14 carbon atoms which may be substituted with a phenyl group which may be substituted with Z 1 , or a heteroaryl group having 2 to 14 carbon atoms which may be substituted with a phenyl group which may be substituted with Z 1 . Examples of these aryl groups and heteroaryl groups include those similar to those described in the description of R 1’ and R 2’ . Among these, as R 156 and R 157 , an aryl group having 6 to 14 carbon atoms which may be substituted with a phenyl group which may be substituted with Z 1 is preferable, 1A phenyl group which may be substituted by a phenyl group which may be replaced by, Z 1 A 1-naphthyl group which may be substituted by a phenyl group which may be substituted by, or Z 1 A 2-naphthyl group which may be substituted by is more preferable.

[0102] In formula (A2), Ar 3 Is a group represented by any of formulas (Ar3-1) to (Ar3-8), and in particular, a group represented by any of formulas (Ar3-1') to (Ar3-8') is preferable. In the following formulas, DPA represents the same meaning as above, and the dashed line represents a bond.

[0103]

Chemical formula

[0104]

Chemical formula

[0105] In formula (A1), p is an integer from 1 to 10. From the viewpoint of enhancing the solubility of the compound in an organic solvent, 1 to 5 is preferable, 1 to 3 is more preferable, 1 or 2 is even more preferable, and 1 is optimal. In formula (A2), q is 1 or 2.

[0106] The aniline derivative represented by formula (A1) and the aniline derivative represented by formula (A2) can be produced, for example, according to the method described in International Publication No. 2015 / 050253.

[0107] Other suitable examples of the above tertiary arylamine compound include, for example, the compound represented by the following formula (A3).

[0108]

Chemical formula

[0109] In formula (A3), r is an integer from 2 to 4. Ar11 is an r-valent aromatic group having 6 to 20 carbon atoms which may be substituted. This aromatic group is a group obtained by removing r hydrogen atoms from the aromatic ring of an aromatic compound having 6 to 20 carbon atoms, and in particular, a group derived from a compound represented by any of the following formulas (A3-1) to (A3-8) is preferable.

[0110]

Chemical formula

[0111] In formulas (A3-3) and (A3-4), L 1 ~L 3 are each independently a single bond, -(CR 201 R 202 ) s -, -C(O)-, -O-, -S-, -S(O)-, -S(O2)- or NR 203 -. s is an integer of 1 to 6. In formulas (A3-5) to (A3-8), L 4 ~L 13 are each independently a single bond, -CR 201 R 202 -, -C(O)-, -O-, -S-, -S(O)-, -S(O2)- or -NR 203 -. R 201 and R 202 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R 201 and R 202 may be bonded to each other to form a ring together with the carbon atom to which they are bonded. In addition, in -(CR 201 R 202 ) s -, when s is 2 or more, each R 201 and R 202 may be the same as or different from each other. R 203 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms.

[0112] In addition, some or all of the hydrogen atoms of the aromatic group may be further substituted with substituents. Examples of such substituents include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, a hydroxy group, an amino group, a silanol group, a thiol group, a carboxy group, a sulfonic acid ester group, a phosphoric acid group, a phosphoric acid ester group, an ester group, a thioester group, an amide group, a monovalent hydrocarbon group, an organooxy group, an organoamino group, an organosilyl group, an organothio group, an acyl group, a sulfo group, etc. Among them, a halogen atom, a nitro group, a cyano group, or a monovalent hydrocarbon group having 1 to 20 carbon atoms is preferable.

[0113] Ar 11 Preferably, they are optionally substituted 1,4-phenylene, fluorene-2,7-diyl, 9,9-dimethylfluorene-2,7-diyl group, etc. More preferably, they are optionally substituted 1,4-phenylene group, biphenyl-4,4'-diyl group.

[0114] In formula (A3), Ar 12 and Ar 13 are each independently a monovalent aromatic group having 6 to 20 carbon atoms which may be substituted with Z 11 . Ar 12 and Ar 13 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. Also, each Ar 12 and Ar 13 may be the same as or different from each other. Z 11 is a halogen atom, a nitro group or a cyano group, or a monovalent aliphatic hydrocarbon group or monovalent aromatic group having 1 to 20 carbon atoms which may be substituted with a halogen atom, or a polymerizable group.

[0115] Examples of the monovalent aromatic group include aryl groups such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl groups.

[0116] The monovalent aliphatic hydrocarbon may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl groups; alkenyl groups having 2 to 20 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, hexenyl groups, etc.

[0117] Examples of the polymerizable group include, but are not limited to, those represented by the following formula.

[0118]

Chemical formula

[0119] R g is a hydrogen atom or a methyl group. R h and R i are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, with a methyl group or an ethyl group being preferred. R j 、R k and R l are each independently a single bond or an alkylene group having 1 to 8 carbon atoms which may contain an oxygen atom, a sulfur atom or a nitrogen atom. R m 、R n and R o are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, n-propyl, etc.

[0120] Y a and Y bis, independently of each other, a single bond or a divalent aromatic group having 6 to 20 carbon atoms. Examples of this divalent aromatic group include 1,3-phenylene, 1,4-phenylene, 1,5-naphthylene, 1,6-naphthylene, 1,7-naphthylene, 2,6-naphthylene, 4,4'-biphenylylene group, etc. Among these, 1,3-phenylene group and 1,4-phenylene group are preferred.

[0121] Ar a is a monovalent aromatic group having 6 to 20 carbon atoms which may have a substituent, and examples of this monovalent aromatic group include the same ones as those described above.

[0122] Z 11 As, a methyl group, an ethyl group, a polymerizable group represented by the following formula, etc. are preferred.

[0123]

Chemical formula

[0124] Ar 12 and Ar 13 As, phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-vinylphenyl, 3-vinylphenyl, 4-vinylphenyl, 1-naphthyl, 2-naphthyl group, etc. are preferred.

[0125] The compound represented by formula (A3) can be synthesized by a known method, or a commercially available product can also be used.

[0126] Other preferred examples of the above tertiary arylamine compound include, for example, those represented by the following formula (A4).

[0127]

Chemical formula

[0128] In formula (A4), Ar21 ~Ar 23 is each independently a divalent aromatic group having 6 to 20 carbon atoms, and as this divalent aromatic group, a divalent group derived from a compound represented by the aforementioned formula (A3-1), (A3-3) or (A3-4) is preferable.

[0129] Among these, Ar 21 ~Ar 23 is preferably 1,4-phenylene, biphenyl-4,4'-diyl, terphenyl-4,4''-diyl group, etc., and more preferably 1,4-phenylene group, biphenyl-4,4'-diyl group.

[0130] In formula (A4), Ar 24 ~Ar 29 is each independently a monovalent aromatic group having 6 to 20 carbon atoms which may be substituted with Z 21 . Specific examples thereof include aryl groups such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl groups, etc.

[0131] Z 21 is a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom, nitro group or cyano group, a halogen atom, nitro group, cyano group, -N(Ar 30 )(Ar 31 ), or a polymerizable group. The monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl groups; alkenyl groups having 2 to 20 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, hexenyl groups and the like. Examples of the polymerizable group include the same ones as those described above.

[0132] Ar 30 and Ar 31 are each independently an aryl group having 6 to 20 carbon atoms which may be substituted with Z 22 , and these may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. Z 22 is a halogen atom, a nitro group or a cyano group, or a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom, a nitro group or a cyano group.

[0133] Examples of the aryl group having 6 to 20 carbon atoms and the monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms include the same ones as those described above.

[0134] Ar 30 and Ar 31 are preferably phenyl, 1-naphthyl, 2-naphthyl, 1-biphenylyl group and the like, and more preferably phenyl group, 1-biphenylyl group and the like. In particular, -N(Ar 30 )(Ar 31 ) is preferably a diphenylamino group, a phenyl(4-biphenylyl)amino group, a bis(4-biphenylyl)amino group, an N-carbazolyl group and the like.

[0135] Z 21 is an alkyl group having 1 to 10 carbon atoms, -N(Ar30 )(Ar 31 ) etc. are preferable.

[0136] Ar 24 ~Ar 29 Examples of Ar include phenyl, 4-biphenylyl, 4-diphenylaminophenyl, 4-phenyl(4-biphenylyl)aminophenyl, bis(4-biphenylyl)aminophenyl, 4'-diphenylamino-4-biphenylyl, 4-phenyl(4-biphenylyl)amino-4-biphenylyl, 4'-bis(4-biphenylyl)amino-4-biphenylyl, N-carbazolylphenyl, 4'-N-carbazolyl-4-biphenylyl group, etc., which are preferable.

[0137] The compound represented by formula (A4) can be synthesized by a known method, or a commercially available product can also be used.

[0138] Other preferable examples of the above tertiary arylamine compound include, for example, those represented by the following formula (A5).

[0139]

Chemical formula

[0140] In formula (A5), Ar 41 and Ar 42 are each independently a phenyl group, a 1-naphthyl group or a 2-naphthyl group. R 301 and R 302 are each independently a hydrogen atom, a diarylaminophenyl group in which each aryl group is an aryl group having 6 to 20 carbon atoms, a chlorine atom, a bromine atom or an iodine atom. Examples of the above aryl group are the same as those described in the description of R 1’ and R 2’ in formula (A2). L 21 is a divalent linking group containing a propane-2,2-diyl group or a 1,1,1,3,3,3-hexafluoropropane-2,2-diyl group. x is an integer of 1 to 10.

[0141] The compound represented by formula (A5) can be synthesized by a known method, or a commercially available product can also be used.

[0142] The above tertiary arylamine compound has at least one nitrogen atom, and is not limited to those described above as long as all nitrogen atoms have a tertiary arylamine structure. Other tertiary arylamine compounds that can be used in the present invention include, for example, the arylamine compounds described in International Publication No. 2005 / 094133, the polymerizable compounds having a triarylamine partial structure and a polymerizable group described in Japanese Patent No. 5287455, the triarylamine compounds described in Japanese Patent No. 5602191, the compounds described in paragraph

[0054] of Japanese Patent No. 6177771, and the like.

[0143] Preferred examples of the above tertiary arylamine compound include, but are not limited to, the following.

[0144]

Chemical formula

[0145]

Chemical formula

[0146]

Chemical formula

[0147]

Chemical formula

[0148]

Chemical formula

[0149]

Chemical formula

[0150] [Chemistry]

[0151] [Chemistry]

[0152] [Chemistry]

[0153] [Chemistry]

[0154] In the organic functional ink used in the present invention, depending on the use of the resulting functional film, in addition to the organic functional materials such as the charge transporting substances described above, a dopant substance may be included for the purpose of improving the charge transporting ability and the like.

[0155] The dopant substance is not particularly limited as long as it is soluble in at least one solvent used in the organic functional ink, and either an inorganic dopant substance or an organic dopant substance can be used. Further, the inorganic and organic dopant substances may be used alone or in combination of two or more. Furthermore, the dopant substance is a substance whose function as a dopant substance is first expressed or improved by an external stimulus such as heating during firing, for example, by a part of the molecule coming off during the process of obtaining an organic functional film which is a solid film from the ink, for example, an aryl sulfonic acid ester compound protected with a group that easily detaches a sulfonic acid group may be used.

[0156] The molecular weight of organic dopants such as arylsulfonic acid compounds and arylsulfonic acid ester compounds is not particularly limited. However, considering their solubility in organic solvents when used together with charge transport materials, it is preferably 4000 or less, more preferably 3000 or less, and even more preferably 2000 or less.

[0157] In particular, in the present invention, as the inorganic dopant material, heteropolyacid is preferred. A heteropolyacid has a structure in which a heteroatom is located at the center of the molecule, typically represented by the Keggin type of formula (H1) or the Dawson type of formula (H2), and is a polyacid formed by the condensation of an isopolyacid, which is an oxygen acid such as vanadium (V), molybdenum (Mo), or tungsten (W), and an oxygen acid of a different element. Examples of such oxygen acids of different elements mainly include oxygen acids of silicon (Si), phosphorus (P), and arsenic (As).

[0158]

Chemical formula

[0159] Specific examples of heteropolyacids include phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, phosphotungstomolybdic acid, etc. These may be used alone or in combination of two or more. These heteropolyacids are available as commercial products and can also be synthesized by known methods. In particular, when using one type of heteropolyacid, the one type of heteropolyacid is preferably phosphotungstic acid or phosphomolybdic acid, and phosphotungstic acid is most optimal. Also, when using two or more types of heteropolyacids, one of the two or more types of heteropolyacids is preferably phosphotungstic acid or phosphomolybdic acid, and phosphotungstic acid is more preferred. In addition, heteropoly acids can be used in the present invention as long as, in quantitative analysis such as elemental analysis, even if the number of elements is large or small in the structure represented by the general formula, it is a commercially available product or a product appropriately synthesized according to a known synthesis method. That is, for example, generally, phosphotungstic acid has the chemical formula H3(PW 12 O 40 )·nH2O, and phosphomolybdic acid has the chemical formula H3(PMo 12 O 40 )·nH2O, respectively. However, in quantitative analysis, even if the number of P (phosphorus), O (oxygen), W (tungsten), or Mo (molybdenum) in this formula is large or small, as long as it is a commercially available product or a product appropriately synthesized according to a known synthesis method, it can be used in the present invention. In this case, the mass of the heteropoly acid defined in the present invention does not refer to the mass of pure phosphotungstic acid (phosphotungstic acid content) in the synthetic product or commercially available product, but means the total mass including water of hydration and other impurities in the form available as a commercially available product and in the form isolable by a known synthesis method.

[0160] The usage amount of the heteropoly acid can be about 0.001 to 50.0, preferably about 0.01 to 20.0, more preferably about 0.1 to 10.0, in terms of mass ratio with respect to the charge transport material 1 such as polythiophene derivatives and arylamine derivatives.

[0161] On the other hand, as the organic dopant substance, tetracyanoquinodimethane derivatives and benzoquinone derivatives can be used. Specific examples of the tetracyanoquinodimethane derivative include 7,7,8,8-tetracyanoquinodimethane (TCNQ) and halotetracyanoquinodimethane represented by the formula (H3). Specific examples of the benzoquinone derivative include 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), tetrachloro-1,4-benzoquinone (chloranil), trifluoro-1,4-benzoquinone, tetrafluoro-1,4-benzoquinone, tetrabromo-1,4-benzoquinone, tetracyano-1,4-benzoquinone, and the like. Among these, 2,3-dichloro-5,6-dicyano-p-benzoquinone, trifluorobenzoquinone, tetrafluorobenzoquinone, and tetracyano benzoquinone are preferable, DDQ, chloranil, tetrafluoro-1,4-benzoquinone, and tetracyano-1,4-benzoquinone are more preferable, and DDQ is even more preferable.

[0162]

Chem.

[0163] In the formula, R 500 ~R 503 each independently represents a hydrogen atom or a halogen atom, at least one of which is a halogen atom, preferably at least two are halogen atoms, more preferably at least three are halogen atoms, and most preferably all are halogen atoms. Examples of the halogen atom are the same as those described above, but a fluorine atom or a chlorine atom is preferable, and a fluorine atom is more preferable.

[0164] Specific examples of such halotetracyanoquinodimethane include 2-fluoro-7,7,8,8-tetracyanoquinodimethane, 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane, tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), tetrachloro-7,7,8,8-tetracyanoquinodimethane, 2-fluoro-7,7,8,8-tetracyanoquinodimethane, 2-chloro-7,7,8,8-tetracyanoquinodimethane, 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane, 2,5-dichloro-7,7,8,8-tetracyanoquinodimethane, and the like. Among these, F4TCNQ is preferable.

[0165] The usage amounts of the tetracyanoquinodimethane derivative and the benzoquinone derivative are preferably 0.0001 to 100 equivalents, more preferably 0.01 to 50 equivalents, and even more preferably 1 to 20 equivalents, relative to organic functional materials such as polythiophene derivatives and arylamine derivatives.

[0166] Specific examples of the arylsulfonic acid compound include benzenesulfonic acid, tosylic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalicylic acid, p-dodecylbenzenesulfonic acid, dihexylbenzenesulfonic acid, 2,5-dihexylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, 6,7-dibutyl-2-naphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, 3-dodecyl-2-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 4-hexyl-1-naphthalenesulfonic acid, octylnaphthalenesulfonic acid, 2-octyl-1-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 7-hexyl-1-naphthalenesulfonic acid, 6-hexyl-2-naphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, 2,7-dinonyl-4-naphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, 2,7-dinonyl-4,5-naphthalenedisulfonic acid, the 1,4-benzooxanedisulfonic acid compound described in International Publication No. 2005 / 000832, the arylsulfonic acid compound described in International Publication No. 2006 / 025342, the arylsulfonic acid compound described in International Publication No. 2009 / 096352, and the like.

[0167] Examples of preferred arylsulfonic acid compounds include arylsulfonic acid compounds represented by formula (H4) or (H5).

[0168]

Chemical formula

[0169] D 1 D represents O or S, with O being preferred. D2 represents a naphthalene ring or an anthracene ring, with the naphthalene ring being preferred. D 3 represents a divalent to tetravalent perfluorobiphenyl group, and s represents the number of 1 bonds between D 3 and D 3 and is an integer satisfying 2 ≤ s ≤ 4. However, D t represents the number of sulfonic acid groups bonded to D 2 and is an integer satisfying 1 ≤ t ≤ 4, with 2 being optimal.

[0170] D 4 ~D 8 each independently represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, or a halogenated alkenyl group having 2 to 20 carbon atoms. However, at least three of D 4 ~D 8 are halogen atoms.

[0171] Examples of the halogenated alkyl group having 1 to 20 carbon atoms include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, 1,1,2,2,3,3,3-heptafluoropropyl, 4,4,4-trifluorobutyl, 3,3,4,4,4-pentafluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, 1,1,2,2,3,3,4,4,4-nonafluorobutyl group, and the like.

[0172] Examples of the halogenated alkenyl group having 2 to 20 carbon atoms include perfluorovinyl, perfluoropropenyl (perfluoroallyl), perfluorobutenyl group, and the like. In addition, examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms are the same as those described above. However, as the halogen atom, a fluorine atom is preferred.

[0173] Among these, D 4 ~D 8 is a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms, and at least 3 of D 4 ~D 8 are preferably fluorine atoms, and are a hydrogen atom, a fluorine atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkenyl group having 2 to 5 carbon atoms, and at least 3 of D 4 ~D 8 are more preferably fluorine atoms, and are a hydrogen atom, a fluorine atom, a cyano group, a nitro group, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkenyl group having 1 to 5 carbon atoms, and D 4 D 5 and D 8 are even more preferably fluorine atoms. In addition, the perfluoroalkyl group is a group in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms, and the perfluoroalkenyl group is a group in which all hydrogen atoms of the alkenyl group are substituted with fluorine atoms.

[0174] u represents the number of sulfonic acid groups bonded to the naphthalene ring and is an integer satisfying 1 ≦ u ≦ 4, preferably 2 to 4, and most preferably 2.

[0175] Hereinafter, specific examples of suitable arylsulfonic acid compounds are given, but the present invention is not limited thereto.

[0176]

Chemical formula

[0177] The usage amount of the arylsulfonic acid compound is preferably about 0.01 to 20.0, more preferably about 0.4 to 5.0, in terms of the molar ratio with respect to the organic functional material 1 such as the polythiophene derivative and the arylamine derivative. The arylsulfonic acid compound may be a commercially available product, or it can also be synthesized by known methods described in International Publication No. 2006 / 025342, International Publication No. 2009 / 096352, etc.

[0178] The arylsulfonic acid ester compound is not particularly limited as long as it has a sulfonic acid ester group bonded to an aromatic ring. In a preferred embodiment of the present invention, the molecular weight of the arylsulfonic acid ester compound is preferably 100 or more, more preferably 200 or more, preferably 5,000 or less, more preferably 4,000 or less, even more preferably 3,000 or less, and still more preferably 2,000 or less. In a preferred embodiment of the present invention, the number of sulfonic acid ester groups possessed by the arylsulfonic acid ester compound is preferably 2 or more, more preferably 3 or more, preferably 6 or less, and more preferably 5 or less. In a preferred embodiment of the present invention, the arylsulfonic acid ester compound preferably contains an aromatic ring substituted with fluorine.

[0179] As the arylsulfonic acid ester compound, those represented by the following formula (B1) or (B1') are preferred.

[0180]

Chemical formula

[0181] In formula (B1) and (B1'), A 1 is an m-valent hydrocarbon group having 6 to 20 carbon atoms and containing one or more aromatic rings, which may have substituents, or an m-valent group derived from a compound represented by the following formula (B1a) or (B1b) (that is, a group obtained by removing m hydrogen atoms on the aromatic ring of the compound represented by the following formula (B1a) or (B1b)).

Chemical formula

[0182] The m-valent hydrocarbon group having one or more aromatic rings and having 6 to 20 carbon atoms is a group obtained by removing m hydrogen atoms from a hydrocarbon having 6 to 20 carbon atoms and having one or more aromatic rings. Examples of the hydrocarbon having one or more aromatic rings include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, pyrene and the like. Among these, as the m-valent hydrocarbon group, groups derived from benzene, biphenyl and the like are preferable.

[0183] In the above hydrocarbon group, some or all of the hydrogen atoms thereof may be further substituted with a substituent. Examples of this substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), nitro, cyano, hydroxy, amino, silanol, thiol, carboxy, sulfonic acid ester, phosphoric acid, phosphoric acid ester, ester, thioester, amide, monovalent hydrocarbon, organooxy, organoamino, organosilyl, organothio, acyl, sulfo group and the like.

[0184] Here, the monovalent hydrocarbon group may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl groups; alkenyl groups having 2 to 10 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, hexenyl groups; aryl groups having 6 to 20 carbon atoms such as phenyl, xylyl, tolyl, 1-naphthyl, 2-naphthyl groups; aralkyl groups having 7 to 20 carbon atoms such as benzyl, phenylethyl groups and the like.

[0185] Specific examples of the above-mentioned organooxy group include alkoxy, alkenyloxy, aryloxy groups, etc. Examples of the alkyl group, alkenyl group, and aryl group contained therein are the same as those described above.

[0186] Specific examples of the above-mentioned organoamino group include alkylamino groups having 1 to 12 carbon atoms such as methylamino, ethylamino, propylamino, butylamino, pentylamino, hexylamino, cyclohexylamino, heptylamino, octylamino, nonylamino, decylamino, dodecylamino groups; dialkylamino groups in which each alkyl group such as dimethylamino, diethylamino, dipropylamino, dibutylamino, dipentylamino, dihexylamino, dicyclohexylamino, diheptylamino, dioctylamino, dinonylamino, didecylamino groups is an alkyl group having 1 to 12 carbon atoms; morpholino groups, etc.

[0187] Specific examples of the above-mentioned organosilyl group include trialkylsilyl groups in which each alkyl group such as trimethylsilyl, triethylsilyl, tripropylsilyl, tributylsilyl, tripentylsilyl, trihexylsilyl, pentyldimethylsilyl, hexyldimethylsilyl, octyldimethylsilyl, decyldimethylsilyl groups is an alkyl group having 1 to 10 carbon atoms. Specific examples of the above-mentioned organothio group include alkylthio groups having 1 to 12 carbon atoms such as methylthio, ethylthio, propylthio, butylthio, pentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio, dodecylthio groups. Examples of the above-mentioned acyl group include acyl groups having 1 to 10 carbon atoms such as formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, benzoyl groups.

[0188] In addition, the number of carbon atoms of these monovalent hydrocarbon groups, organooxy groups, organoamino groups, organosilyl groups, organothio groups, and acyl groups is preferably 1 to 8.

[0189] Among these substituents, a fluorine atom, a sulfonic acid group, an alkyl group, an organooxy group, and an organosilyl group are more preferable.

[0190] In formula (B1), A 2 is -O-, -S-, or -NH-. Among these, -O- is preferable because the synthesis is easy.

[0191] In formula (B1), A 3 is an (n + 1)-valent aromatic group having 6 to 20 carbon atoms. The (n + 1)-valent aromatic group is a group obtained by removing (n + 1) hydrogen atoms on the aromatic ring from an aromatic compound having 6 to 20 carbon atoms. In the present invention, the aromatic compound means an aromatic hydrocarbon and an aromatic heterocyclic compound. Examples of the aromatic compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, pyrene, etc. Among these, as the aromatic group represented by A 3 a group derived from naphthalene or anthracene is preferable.

[0192] In formulas (B1) and (B1'), X 1 is an alkylene group having 2 to 5 carbon atoms, and in this alkylene group, -O-, -S-, or a carbonyl group may be interposed between its carbon atoms (carbon-carbon bond), and a part or all of its hydrogen atoms may be further substituted with an alkyl group having 1 to 20 carbon atoms. X 1 is preferably ethylene, trimethylene, methyleneoxymethylene, methylenethiomethylene group, etc., and a part or all of the hydrogen atoms of these groups may be further substituted with an alkyl group having 1 to 20 carbon atoms. Examples of this alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, bicyclohexyl group, etc.

[0193] In formulas (B1) and (B1'), X 2 is a single bond, -O-, -S- or NR-. R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. As this monovalent hydrocarbon group, an alkyl group such as a methyl, ethyl, n-propyl group or the like is preferable. X 2 is preferably a single bond, -O- or -S-, more preferably a single bond or -O-.

[0194] In formulas (B1) and (B1'), X 3 is an optionally substituted monovalent hydrocarbon group having 1 to 20 carbon atoms. This monovalent hydrocarbon group may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, bicyclohexyl group; alkenyl groups having 2 to 20 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, hexenyl group; aryl groups having 6 to 20 carbon atoms such as phenyl, xylyl, tolyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl group; aralkyl groups having 7 to 20 carbon atoms such as benzyl, phenylethyl, phenylcyclohexyl group and the like. Further, some or all of the hydrogen atoms of the above monovalent hydrocarbon group may be further substituted with a substituent. Examples of this substituent include those described in the description of A 1 which are the same as those described above. X 3 is preferably an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms.

[0195] In formulas (B1) and (B1'), m is an integer satisfying 1 ≦ m ≦ 4, with 2 being preferred. n is an integer satisfying 1 ≦ n ≦ 4, with 2 being preferred.

[0196] The aryl sulfonate compounds represented by formulas (B1) and (B1') exhibit high solubility in a wide range of solvents including low-polarity solvents. Therefore, it is possible to prepare the physical properties of the solution using a variety of solvents, and the coating properties are high. For this reason, it is preferable to apply in the form of a sulfonate ester and generate sulfonic acid during drying or firing of the coating film. The temperature at which sulfonic acid is generated from the sulfonate ester is preferably stable at room temperature and below the firing temperature, so 40 to 260 °C is suitable. Furthermore, considering high stability in the varnish and ease of elimination during firing, 80 to 230 °C is preferred, and 120 to 180 °C is more preferred.

[0197] As the aryl sulfonate compound represented by formula (B1), those represented by any of the following formulas (B1-1) to (B1-3) are preferred.

[0198]

Chemical formula

[0199] In formula (B1-1), A 11 is an m-valent group derived from perfluorobiphenyl (i.e., a group obtained by removing m fluorine atoms from perfluorobiphenyl). A 12 is -O- or -S-, with -O- being preferred. A 13 is an (n + 1)-valent group derived from naphthalene or anthracene (i.e., a group obtained by removing (n + 1) hydrogen atoms from naphthalene or anthracene), with a group derived from naphthalene being preferred.

[0200] In formula (B1-1), R s1 ~R s4 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and Rs5 is a monovalent hydrocarbon group having 2 to 20 carbon atoms which may be substituted.

[0201] Specific examples of the linear or branched alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl group and the like. Among these, an alkyl group having 1 to 3 carbon atoms is preferable.

[0202] The monovalent hydrocarbon group having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include alkyl groups such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl group; aryl groups such as phenyl, naphthyl, phenanthryl group and the like.

[0203] R s1 ~R s4 Among them, it is preferable that R s1 or R s3 is a linear alkyl group having 1 to 3 carbon atoms and the rest are hydrogen atoms. Further, it is preferable that R s1 is a linear alkyl group having 1 to 3 carbon atoms and R s2 ~R s4 are hydrogen atoms. As the linear alkyl group having 1 to 3 carbon atoms, a methyl group is preferable. Also, as R s5 a linear alkyl group having 2 to 4 carbon atoms or a phenyl group is preferable.

[0204] In formula (B1-1), m is an integer satisfying 1 ≦ m ≦ 4, and 2 is preferable. n is an integer satisfying 1 ≦ n ≦ 4, and 2 is preferable.

[0205] In formula (B1-2), A 14is an m-valent hydrocarbon group having 6 to 20 carbon atoms and containing one or more aromatic rings, which may be substituted. The m-valent hydrocarbon group is a group obtained by removing m hydrogen atoms from a hydrocarbon having 6 to 20 carbon atoms and containing one or more aromatic rings. Examples of the hydrocarbon include benzene, toluene, xylene, ethylbenzene, biphenyl, naphthalene, anthracene, phenanthrene, and the like.

[0206] In addition, some or all of the hydrogen atoms of the hydrocarbon group may be further substituted with substituents. Examples of such substituents include halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom), nitro, cyano, hydroxy, amino, silanol, thiol, carboxy, sulfonic acid ester, phosphoric acid, phosphoric acid ester, ester, thioester, amide, monovalent hydrocarbon, organooxy, organoamino, organosilyl, organothio, acyl, sulfo group, and the like. Among these, A 14 is preferably a group derived from benzene, biphenyl, or the like.

[0207] In formula (B1-2), A 15 is -O- or -S-, with -O- being preferred.

[0208] In formula (B1-2), A 16 is an (n + 1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms. The (n + 1)-valent aromatic hydrocarbon group is a group obtained by removing (n + 1) hydrogen atoms from the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. Examples of the aromatic hydrocarbon compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, pyrene, and the like. Among these, A 16 is preferably a group derived from naphthalene or anthracene, and more preferably a group derived from naphthalene.

[0209] In formula (B1-2), R s6 and R s7 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group. R s8is a linear or branched monovalent aliphatic hydrocarbon group. However, R s6 and R s7 and R s8 have a total carbon number of 6 or more. R s6 and R s7 and R s8 The upper limit of the total carbon number of is not particularly limited, but is preferably 20 or less, more preferably 10 or less.

[0210] Specific examples of the linear or branched monovalent aliphatic hydrocarbon group include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, decyl groups; alkenyl groups having 2 to 20 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, hexenyl groups and the like.

[0211] R s6 is preferably a hydrogen atom, and R s7 and R s8 are preferably alkyl groups having 1 to 6 carbon atoms. In this case, R s7 and R s8 may be the same or different.

[0212] In formula (B1-2), m is an integer satisfying 1 ≦ m ≦ 4, but 2 is preferred. n is an integer satisfying 1 ≦ n ≦ 4, but 2 is preferred.

[0213] In formula (B1-3), R s9 to R s13 are each independently a hydrogen atom, a nitro group, a cyano group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms.

[0214] The alkyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl groups and the like.

[0215] The halogenated alkyl group having 1 to 10 carbon atoms is not particularly limited as long as part or all of the hydrogen atoms of the alkyl group having 1 to 10 carbon atoms are substituted with halogen atoms. The halogenated alkyl group may be linear, branched or cyclic, and specific examples thereof include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, 1,1,2,2,3,3,3-heptafluoropropyl, 4,4,4-trifluorobutyl, 3,3,4,4,4-pentafluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, 1,1,2,2,3,3,4,4,4-nonafluorobutyl groups and the like.

[0216] The halogenated alkenyl group having 2 to 10 carbon atoms is not particularly limited as long as part or all of the hydrogen atoms of the alkenyl group having 2 to 10 carbon atoms are substituted with halogen atoms. Specific examples thereof include perfluorovinyl, perfluoro-1-propenyl, perfluoro-2-propenyl, perfluoro-1-butenyl, perfluoro-2-butenyl, perfluoro-3-butenyl groups and the like.

[0217] Among these, R s9 is preferably a nitro group, a cyano group, a halogenated alkyl group having 1 to 10 carbon atoms, a halogenated alkenyl group having 2 to 10 carbon atoms and the like, more preferably a nitro group, a cyano group, a halogenated alkyl group having 1 to 4 carbon atoms, a halogenated alkenyl group having 2 to 4 carbon atoms and the like, and even more preferably a nitro group, a cyano group, a trifluoromethyl group, a perfluoropropenyl group and the like. Also, R s10 ~R s13As for this, a halogen atom is preferable, and a fluorine atom is more preferable.

[0218] In formula (B1-3), A 17 is -O-, -S- or -NH-, and -O- is preferable.

[0219] In formula (B1-3), A 18 is an (n + 1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms. The (n + 1)-valent aromatic hydrocarbon group is a group obtained by removing (n + 1) hydrogen atoms from the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. Examples of the aromatic hydrocarbon compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, pyrene and the like. Among these, as A 18 a group derived from naphthalene or anthracene is preferable, and a group derived from naphthalene is more preferable.

[0220] In formula (B1-3), R s14 ~R s17 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. The monovalent aliphatic hydrocarbon group may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl groups; alkenyl groups having 2 to 20 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, hexenyl groups and the like. Among these, an alkyl group having 1 to 20 carbon atoms is preferable, an alkyl group having 1 to 10 carbon atoms is more preferable, and an alkyl group having 1 to 8 carbon atoms is even more preferable.

[0221] In formula (B1-3), R s18 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or OR s19is R. s19 R is a monovalent hydrocarbon group having 2 to 20 carbon atoms, which may be substituted.

[0222] R s18 Examples of the linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by R include those similar to those described in the description of R s14 ~R s17 ~R s18 When R is a monovalent aliphatic hydrocarbon group, R s18 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and even more preferably an alkyl group having 1 to 8 carbon atoms.

[0223] R s19 Examples of the monovalent hydrocarbon group having 2 to 20 carbon atoms represented by R include, in addition to those other than the methyl group among the aforementioned monovalent aliphatic hydrocarbon groups, aryl groups such as phenyl group, naphthyl group, and phenanthryl group. Among these, R s19 is preferably a linear alkyl group having 2 to 4 carbon atoms or a phenyl group. Examples of the substituent that the above monovalent hydrocarbon group may have include a fluorine atom, an alkoxy group having 1 to 4 carbon atoms, a nitro group, a cyano group, and the like.

[0224] In formula (B1-3), n is an integer satisfying 1 ≤ n ≤ 4, and 2 is preferred.

[0225] As the aryl sulfonate compound represented by formula (B1-3), those represented by the following formula (B1-3-1) or (B1-3-2) are particularly preferred.

[0226]

Chemical formula

[0227] In formulas (B1-3-1) and (B1-3-2), A 17 、A 18 、R s9 ~R s17 、R s19 and n represent the same meanings as described above. Rs20 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, and specific examples thereof include those described in the description of R s18 which are the same as those described above.

[0228] In the aryl sulfonate compound represented by the formula (B1-3-1), R s14 ~R s17 Among them, R s14 or R s16 is preferably a linear alkyl group having 1 to 3 carbon atoms, and the rest are hydrogen atoms. Further, R s14 is preferably a linear alkyl group having 1 to 3 carbon atoms, and R s15 ~R s17 are preferably hydrogen atoms. As this linear alkyl group having 1 to 3 carbon atoms, a methyl group is preferable. Also, as R s19 is preferably a linear alkyl group having 2 to 4 carbon atoms or a phenyl group.

[0229] In the aryl sulfonate compound represented by the formula (B1-3-2), the total number of carbon atoms of R s14 , R s16 and R s20 is preferably 6 or more. The upper limit of the total number of carbon atoms of R s14 , R s16 and R s20 is preferably 20 or less, and more preferably 10 or less. In this case, as R s14 a hydrogen atom is preferable, and as R s16 and R s20 alkyl groups having 1 to 6 carbon atoms are preferable. Also, R s16 and R s20 may be the same as or different from each other.

[0230] The aryl sulfonate compound represented by the formula (B1) may be used alone or in combination of two or more.

[0231] Specific examples of suitable aryl sulfonate compounds include, but are not limited to, those shown below.

[0232]

Chem.

[0233]

Chem.

[0234] The aryl sulfonate compound represented by formula (B1) can be synthesized, for example, as shown in the following Scheme A, by reacting a sulfonate compound represented by formula (B1A) with a halogenating agent to synthesize a sulfonyl halide compound represented by the following formula (B1B) (hereinafter also referred to as Step 1), and then reacting this sulfonyl halide compound with a compound represented by formula (B1C) (hereinafter also referred to as Step 2).

[0235]

Chem.

[0236] The sulfonate compound represented by formula (B1A) can be synthesized according to a known method.

[0237] Examples of the halogenating agent used in Step 1 include halogenating agents such as thionyl chloride, oxalyl chloride, phosphorus oxychloride, and phosphorus(V) chloride, with thionyl chloride being preferred. The amount of the halogenating agent used is not limited as long as it is 1 mole or more relative to the sulfonate compound, but it is preferably used in an amount of 2 to 10 times the mass of the sulfonate compound.

[0238] As the reaction solvent used in Step 1, a solvent that does not react with the halogenating agent is preferred, and examples thereof include chloroform, dichloroethane, carbon tetrachloride, hexane, heptane, etc. Also, the reaction can be carried out without a solvent. In this case, it is preferred to use a halogenating agent in an amount equal to or more than the amount that forms a homogeneous solution at the end of the reaction. Further, to accelerate the reaction, a catalyst such as N,N-dimethylformamide may be used. The reaction temperature can be about 0 to 150°C, but 20 to 100°C and below the boiling point of the halogenating agent used are preferred. After completion of the reaction, generally, the crude product obtained by concentration under reduced pressure or the like is used in the next step.

[0239] Examples of the compound represented by the formula (B1C) include glycol ethers such as propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monophenyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether; alcohols such as 2-ethyl-1-hexanol, 2-butyl-1-octanol, 1-octanol, 3-nonanol, etc.

[0240] In Step 2, a base may be used in combination. Examples of the usable base include sodium hydride, pyridine, triethylamine, diisopropylethylamine, etc., and sodium hydride, pyridine, and triethylamine are preferred. The amount of the base used is preferably 1-fold molar to the amount of the solvent with respect to the sulfonyl halide compound.

[0241] As the reaction solvent used in Step 2, various organic solvents can be used, but tetrahydrofuran, dichloroethane, chloroform, and pyridine are preferred. The reaction temperature is not particularly limited, but 0 to 80°C is preferred. After completion of the reaction, post-treatment and purification are carried out using conventional methods such as concentration under reduced pressure, liquid-liquid extraction, washing with water, reprecipitation, recrystallization, chromatography, etc. to obtain a pure aryl sulfonate compound. Note that a high-purity sulfonic acid compound can also be obtained by subjecting the obtained pure aryl sulfonate compound to heat treatment or the like.

[0242] Further, the aryl sulfonate compound represented by formula (B1) can also be synthesized from the sulfonic acid compound represented by formula (B1D) as shown in the following Scheme B. In the following Scheme B, the halogenating agent, the compound represented by formula (B1C), the reaction solvent, and other components used in the first and second steps can be the same as those in Steps 1 and 2 of Scheme A.

[0243]

Chemical formula

[0244] The sulfonic acid compound represented by formula (B1D) can be synthesized according to a known method.

[0245] The aryl sulfonate compound represented by formula (B1') can be synthesized according to a conventionally known method, for example, the method described in Japanese Patent No. 5136795.

[0246] The amount of the aryl sulfonate compound used is preferably about 0.01 to 20.0, more preferably about 0.05 to 15, in terms of the molar ratio of the amount of substance, relative to the organic functional material 1 such as the polythiophene derivative or the arylamine derivative.

[0247] Particularly, in the present invention, when the charge transporting substance is a polythiophene derivative, considering enhancing the flatness of the film and the like when the organic functional ink is applied into the partition formed on the substrate by the inkjet method, it is preferable to use at least one of an aryl sulfonic acid compound and an aryl sulfonate compound as the dopant substance, and it is more preferable to use an aryl sulfonic acid compound.

[0248] In addition, in the case where the charge transporting substance is a monodisperse charge transporting organic compound such as a tertiary arylamine compound represented by the above formula (A1) or (A2), from the same viewpoint as above, as the dopant substance, it is preferable to use one containing an arylsulfonic acid ester compound and a halogenated tetracyanoquinodimethane or a halogenated or cyanated benzoquinone. In this case, the content of the arylsulfonic acid ester compound is usually an amount such that the molar ratio to the halogenated tetracyanoquinodimethane or the halogenated or cyanated benzoquinone is about 0.01 to 50, preferably about 0.1 to 20, and more preferably about 1.0 to 10. Further, the total content of the dopant substance is an amount such that the ratio (D / H) of the content of the dopant to the charge transporting substance is usually about 0.01 to 50 in terms of molar ratio, preferably about 0.1 to 10, and more preferably about 1.0 to 5.0.

[0249] Furthermore, the organic functional ink used in the present invention may contain one or more metal oxide nanoparticles. Nanoparticles mean fine particles having an average particle diameter of the order of nanometers (typically 500 nm or less) for primary particles. Metal oxide nanoparticles mean metal oxides formed into nanoparticles. The primary particle diameter of the metal oxide nanoparticles is not particularly limited as long as it is in the nano size, but is preferably 2 to 150 nm, more preferably 3 to 100 nm, and even more preferably 5 to 50 nm. The particle diameter is a measured value using a nitrogen adsorption isotherm by the BET method.

[0250] The metal constituting the above metal oxide nanoparticles includes semimetals in addition to metals in the ordinary sense. The metal in the ordinary sense is not particularly limited, but it is preferable to use one or more selected from the group consisting of tin (Sn), titanium (Ti), aluminum (Al), zirconium (Zr), zinc (Zn), niobium (Nb), tantalum (Ta), and W (tungsten). On the one hand, a semimetal means an element whose chemical and / or physical properties are intermediate between those of a metal and a nonmetal. Although a universal definition of a semimetal has not been established, in the present invention, a total of six elements, namely boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te), are regarded as semimetals. These semimetals may be used alone, in combination of two or more, or in combination with a metal in the ordinary sense.

[0251] In particular, the metal oxide nanoparticles preferably contain an oxide of one or more metals selected from boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), tin (Sn), titanium (Ti), aluminum (Al), zirconium (Zr), zinc (Zn), niobium (Nb), tantalum (Ta), and W (tungsten). When the metal is a combination of two or more, the metal oxide may be a mixture of oxides of individual single metals or a composite oxide containing a plurality of metals.

[0252] Specific examples of the metal oxide include B2O3, B2O, SiO2, SiO, GeO2, GeO, As2O4, As2O3, As2O5, Sb2O3, Sb2O5, TeO2, SnO2, ZrO2, Al2O3, ZnO, etc. Among them, B2O3, B2O, SiO2, SiO, GeO2, GeO, As2O4, As2O3, As2O5, SnO2, SnO, Sb2O3, TeO2, and mixtures thereof are preferred, and SiO2 is more preferred.

[0253] The amount of the metal oxide nanoparticles is not particularly limited, but from the viewpoints of improving the transparency of the obtained thin film and enhancing the uniformity of the film, etc., in the solid content, its lower limit is usually 50% by mass, preferably 60% by mass, more preferably 65% by mass, and its upper limit is usually 95% by mass, preferably 90% by mass.

[0254] In particular, in the present invention, it is preferable to use a silica sol in which SiO2 nanoparticles are dispersed in a dispersion medium as the metal oxide nanoparticles. The silica sol is not particularly limited and can be appropriately selected from known silica sols for use. Commercially available silica sols are usually in the form of a dispersion. Examples of commercially available silica sols include those in which SiO2 nanoparticles are dispersed in various solvents such as water, methanol, methyl ethyl ketone, methyl isobutyl ketone, N,N-dimethylacetamide, ethylene glycol, isopropanol, methanol, ethylene glycol monopropyl ether, cyclohexanone, ethyl acetate, toluene, propylene glycol monomethyl ether acetate, etc.

[0255] Specific examples of commercially available silica sols include water-dispersed silica sols such as Snowtex (registered trademark) ST-O, ST-OS, ST-O-40, ST-OL manufactured by Nissan Chemical Industries, Ltd., and Silicadol 20, 30, 40 manufactured by Nippon Chemical Industry Co., Ltd.; organosilica sols such as methanol silica sols, MA-ST-M, MA-ST-L, IPA-ST, IPA-ST-L, IPA-ST-ZL, EG-ST manufactured by Nissan Chemical Industries, Ltd., etc., but are not limited thereto. Also, the solid content concentration of the silica sol is not particularly limited, but is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 15 to 30% by mass.

[0256] In addition, in order to enhance the effect of suppressing the variation in the shape of the organic functional layer caused by the difference in the timing of ink application, if necessary, it is preferable to replace the solvent of the silica sol with a solvent having properties suitable for the ink solvent such as propylene glycol and use it.

[0257] The amount of the silica sol to be used is appropriately determined in consideration of its concentration so that the amount of silica finally contained in the ink becomes the blending amount of the above-described metal oxide nanoparticles.

[0258] In addition, the organic functional ink used in the present invention may contain an organic silane compound for the purpose of adjusting the film physical properties of the obtained thin film. Examples of the organic silane compound include dialkoxysilane compounds, trialkoxysilane compounds, or tetraalkoxysilane compounds. In particular, as the organic silane compound, dialkoxysilane compounds or trialkoxysilane compounds are preferable, and trialkoxysilane compounds are more preferable. The organic silane compound may be used alone or in combination of two or more. When using an organic silane compound, its usage amount is usually about 0.1 to 50% by mass in the solid content. However, considering the balance such as improving the flatness of the obtained thin film and suppressing the deterioration of desired properties such as charge transport properties, it is preferably about 0.5 to 40% by mass, more preferably about 0.8 to 30% by mass, and even more preferably about 1 to 20% by mass.

[0259] The solid content concentration of the organic functional ink used in the present invention is usually about 0.1 to 20.0% by mass. Considering improving the coating property of the ink, it is preferably about 0.5 to 10.0% by mass, more preferably about 1.0 to 5.0% by mass. The solid content concentration is appropriately set in consideration of the thickness of the functional film to be produced.

[0260] The viscosity of the organic functional ink cannot be generally specified because it varies depending on the amount of droplets dropped by the inkjet method, etc. Usually, it is 15 cP (mPa·s) or less at 25°C, and preferably 10 cP (mPa·s) or less. In addition, the surface tension of the organic functional ink is usually 20 to 50 mN / m at 25°C, preferably 25 to 45 mN / m, and more preferably 37 to 42 mN / m. The viscosity and surface tension of the organic functional ink can be adjusted by changing the types of the above-mentioned ink solvents, their ratios, the solid content concentration, etc. in consideration of various factors such as the desired film thickness.

[0261] In the present invention, the method for preparing the organic functional ink is not particularly limited. For example, an organic functional material such as the above-described polythiophene derivative or arylamine derivative is dissolved in an ink solvent (mixed solvent) containing a low-volatility high-viscosity solvent, or an organic functional material is dissolved in any one of the solvents constituting the ink solvent, and then the other solvents are mixed. When using other components such as a dopant substance, the addition order is also arbitrary. In addition, when preparing the organic functional ink, from the viewpoint of obtaining a more flat thin film with good reproducibility, it is desirable to dissolve the organic functional material, dopant substance, etc. in an organic solvent and then filter using a filter on the submicrometer order.

[0262] The substrate with partitions on which the above-described organic functional ink is applied is not particularly limited as long as it is a substrate on which a predetermined pattern is formed by a known photoresist method or the like. Usually, there are a plurality of openings defined by partitions on the substrate. Usually, the size of the opening is 100 to 250 μm for the long side and 40 to 100 μm for the short side, and the bank taper angle is 20 to 80°. The material of the substrate is not particularly limited, but in the present invention, transparent electrode materials typified by indium tin oxide (ITO) and indium zinc oxide (IZO) used as the anode material of an electronic device; metal anode materials composed of metals typified by aluminum, gold, silver, copper, indium, etc., or alloys thereof; polymer anode materials such as polythiophene derivatives and polyaniline derivatives having high charge transport properties, etc. are mentioned, and those subjected to a planarization treatment are preferred.

[0263] After applying the above-described organic functional ink into the partitions of the substrate with partitions by an inkjet method using an inkjet device, reducing the pressure, and further heating if necessary, the solvent is removed from the organic functional ink applied in the partitions to produce an organic functional film, and a substrate with an organic functional film can be manufactured. Furthermore, by laminating other functional films on this organic functional film, an electronic device such as an organic EL element can be manufactured. At this time, the heating and firing atmosphere during and after inkjet coating is not particularly limited, and it may be any of an air atmosphere, an inert gas atmosphere such as nitrogen, or under reduced pressure. However, depending on the type of dopant substance used together with an organic functional material such as a polythiophene derivative or an arylamine derivative, a functional film having good characteristics may be obtained with good reproducibility by heating and firing in an air atmosphere.

[0264] The degree of reduced pressure (vacuum degree) during reduced pressure is not particularly limited as long as the ink solvent evaporates. However, in the present invention, it is usually 1,000 Pa or less, preferably 100 Pa or less, more preferably 50 Pa or less, even more preferably 25 Pa or less, and still more preferably 10 Pa or less. The reduced pressure time is also not particularly limited as long as the solvent evaporates. However, it is usually about 0.1 to 60 minutes, and preferably about 1 to 30 minutes.

[0265] When heating and firing, the temperature is appropriately set within a range of about 100 to 260 °C in consideration of the use of the obtained functional film, the type and boiling point of the solvent, etc. However, when using the above-mentioned polythiophene derivative arylamine derivative as an organic functional material and using the obtained functional film as a hole injection layer of an organic EL element, from the viewpoint of enhancing the charge transport property of the functional film, about 140 to 250 °C is preferable, and about 145 to 240 °C is more preferable. In addition, when heating and firing, a temperature change in two or more steps may be provided for the purpose of expressing higher uniform film formation properties or advancing the reaction on the substrate. Heating may be performed using an appropriate device such as a hot plate or an oven.

[0266] The film thickness of the organic functional film produced in the present invention is not particularly limited. However, when used as a functional layer provided between the anode and the light-emitting layer such as a hole injection layer, a hole transport layer, or a hole injection transport layer of an organic EL element, 5 to 300 nm is preferable. As a method for changing the film thickness, there are methods such as changing the solid content concentration in the organic functional ink or changing the amount of ink on the substrate during coating.

[0267] As described above, the electronic device fabricated according to the present invention includes an organic functional film - attached substrate produced by applying, by an ink - jet method, an organic functional ink containing an organic functional material and an ink solvent containing a low - volatility, high - viscosity solvent in a predetermined ratio into the partition walls of a partition - wall - attached substrate, and then removing the solvent under reduced pressure. Specific examples thereof include a substrate having a pair of electrodes, with partition walls of a predetermined pattern formed on the surface of at least one of the electrodes, and the partition - wall interior containing an organic functional film - attached substrate produced by applying the above - described organic functional ink by an ink - jet method or the like and various functional films formed thereon.

[0268] In particular, the electronic device fabricated according to the present invention preferably has an organic EL device having the following configurations (a) to (f), but is not limited thereto, where the electrode on which the above - described partition walls are formed is an anode, and the above - described organic functional film is a hole - injection layer or a hole - injection and transport layer formed on this anode. The organic functional film produced from the organic functional ink containing the above - described polythiophene derivative or arylamine derivative can be used as a hole - injection layer, a hole - transport layer, or a hole - injection and transport layer in an organic EL device. However, in the present invention, since it is applied by an ink - jet method into the partition walls formed on the anode, it is used as a hole - injection layer or a hole - injection and transport layer, and is particularly preferably used as a hole - injection layer. (a) Anode / Hole - injection layer / Hole - transport layer / Light - emitting layer / Electron - transport layer / Electron - injection layer / Cathode (b) Anode / Hole - injection layer / Hole - transport layer / Light - emitting layer / Electron - injection and transport layer / Cathode (c) Anode / Hole - injection and transport layer / Light - emitting layer / Electron - transport layer / Electron - injection layer / Cathode (d) Anode / Hole - injection and transport layer / Light - emitting layer / Electron - injection and transport layer / Cathode (e) Anode / Hole - injection layer / Hole - transport layer / Light - emitting layer / Cathode (f) Anode / Hole - injection and transport layer / Light - emitting layer / Cathode

[0269] In each of the above-described configurations, if necessary, an electron blocking layer or the like can be provided between the light-emitting layer and the anode, and a hole (positive hole) blocking layer or the like can be provided between the light-emitting layer and the cathode. Further, the hole injection layer, the hole transport layer, or the hole injection and transport layer may also have the function of an electron blocking layer or the like, and the electron injection layer, the electron transport layer, or the electron injection and transport layer may also have the function of a hole (positive hole) blocking layer or the like. Furthermore, in the present invention, it is also possible to provide an arbitrary functional layer between each layer as necessary, other than between the anode and the hole injection layer or the hole injection and transport layer.

[0270] The "hole injection layer", the "hole transport layer", and the "hole injection and transport layer" are layers formed between the light-emitting layer and the anode, and have the function of transporting holes from the anode to the light-emitting layer. When only one layer of a hole-transporting material is provided between the light-emitting layer and the anode, it is the "hole injection and transport layer". When two or more layers of a hole-transporting material are provided between the light-emitting layer and the anode, the layer closer to the anode is the "hole injection layer", and the other layers are the "hole transport layer". In particular, for the hole injection (transport) layer, a thin film that is excellent not only in hole acceptance from the anode but also in hole injection into the hole transport (light-emitting) layer is used. The "electron injection layer", the "electron transport layer", and the "electron injection and transport layer" are layers formed between the light-emitting layer and the cathode, and have the function of transporting electrons from the cathode to the light-emitting layer. When only one layer of an electron-transporting material is provided between the light-emitting layer and the cathode, it is the "electron injection and transport layer". When two or more layers of an electron-transporting material are provided between the light-emitting layer and the cathode, the layer closer to the cathode is the "electron injection layer", and the other layers are the "electron transport layer". The "light-emitting layer" is an organic layer having a light-emitting function, and when a doping system is adopted, it contains a host material and a dopant material. At this time, the host material mainly has the function of promoting the recombination of electrons and holes and confining excitons within the light-emitting layer, and the dopant material has the function of efficiently emitting the excitons obtained by recombination. In the case of a phosphorescent element, the host material mainly has the function of confining the excitons generated by the dopant within the light-emitting layer.

[0271] When manufacturing an organic EL element using the above-described organic functional ink containing a polythiophene derivative or an arylamine derivative, examples of the materials used and the manufacturing method include, but are not limited to, the following.

[0272] An example of a method for manufacturing an OLED element having a hole injection layer made of a thin film obtained from the above-described organic functional ink is as follows. Note that, within a range that does not adversely affect the electrodes, it is preferable to perform surface treatment such as cleaning with alcohol, pure water, etc., or UV ozone treatment, oxygen-plasma treatment, etc. in advance. On an anode substrate on which a partition wall with a predetermined pattern has been formed in advance, a hole injection layer is formed using the above-described organic functional ink by the above method. This is introduced into a vacuum deposition apparatus, and a hole transport layer, a light-emitting layer, an electron transport layer / hole blocking layer, an electron injection layer, and a cathode metal are sequentially deposited. Alternatively, instead of forming the hole transport layer and the light-emitting layer by vapor deposition in this method, these layers are formed by a wet process using a composition for forming a hole transport layer containing a hole-transporting polymer and a composition for forming a light-emitting layer containing a light-emitting polymer. Note that, if necessary, an electron blocking layer may be provided between the light-emitting layer and the hole transport layer.

[0273] Examples of the anode material include transparent electrodes typified by indium tin oxide (ITO) and indium zinc oxide (IZO), metals typified by aluminum, or metal anodes composed of alloys thereof, etc., and those subjected to a planarization process are preferable. Polythiophene derivatives and polyaniline derivatives having high charge transport properties can also be used. Note that examples of other metals constituting the metal anode include, but are not limited to, gold, silver, copper, indium, and alloys thereof.

[0274] Examples of materials for forming the hole transport layer include triarylamines such as (triphenylamine) dimer derivatives, [(triphenylamine) dimer] spiro dimers, N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (α-NPD), 4,4',4”-tris[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA), 4,4',4”-tris[1-naphthyl(phenyl)amino]triphenylamine (1-TNATA), and oligothiophenes such as 5,5”-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2’:5’,2”-terthiophene (BMA-3T).

[0275] Examples of materials for forming the light-emitting layer include metal complexes such as aluminum complexes of 8-hydroxyquinoline, metal complexes of 10-hydroxybenzo[h]quinoline, bisstyrylbenzene derivatives, bisstyrylarylene derivatives, metal complexes of (2-hydroxyphenyl)benzothiazole, and low-molecular-weight light-emitting materials such as silole derivatives; systems in which a light-emitting material and an electron transport material are mixed in a polymer compound such as poly(p-phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly(3-alkylthiophene), and polyvinylcarbazole. When forming the light-emitting layer by vapor deposition, co-vapor deposition with a light-emitting dopant may be performed. Examples of the light-emitting dopant include metal complexes such as tris(2-phenylpyridine)iridium(III) (Ir(ppy)3), naphthalene derivatives such as rubrene, quinacridone derivatives, and condensed polycyclic aromatic rings such as perylene.

[0276] Examples of materials for forming the electron transport layer / hole blocking layer include oxydiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, and pyrimidine derivatives.

[0277] Examples of materials for forming the electron injection layer include metal oxides such as lithium oxide (Li2O), magnesium oxide (MgO), and alumina (Al2O3), and metal fluorides such as lithium fluoride (LiF) and sodium fluoride (NaF). Examples of the cathode material include aluminum, magnesium-silver alloy, and aluminum-lithium alloy. Examples of materials for forming the electron blocking layer include tris(phenylpyrazole)iridium.

[0278] Examples of hole-transporting polymers include poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene)], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,1'-biphenylene-4,4-diamine)], poly[(9,9-bis{1'-penten-5'-yl}fluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene)], poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine]-end-capped with polysilsesquioxane, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)], and the like.

[0279] Examples of light-emitting polymers include polyfluorene derivatives such as poly(9,9-dialkylfluorene) (PDAF), polyphenylene vinylene derivatives such as poly(2-methoxy-5-(2'-ethylhexoxy)-1,4-phenylenevinylene) (MEH-PPV), polythiophene derivatives such as poly(3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

[0280] The materials constituting the anode, the cathode, and the layers formed therebetween differ depending on whether an element having a bottom emission structure or a top emission structure is to be manufactured. Therefore, the materials are appropriately selected in consideration of this point. Generally, in an element with a bottom emission structure, a transparent anode is used on the substrate side, and light is extracted from the substrate side. On the other hand, in an element with a top emission structure, a reflective anode made of metal is used, and light is extracted from the transparent electrode (cathode) side in the direction opposite to the substrate. Therefore, for example, regarding the anode material, when manufacturing an element with a bottom emission structure, a transparent anode such as ITO is used, and when manufacturing an element with a top emission structure, a reflective anode such as Al / Nd is used, respectively.

[0281] Note that, in order to prevent deterioration of characteristics, the organic EL element may be sealed according to a standard method, together with a water scavenger or the like as necessary.

[0282] According to the present invention described above, since the organic functional ink containing a predetermined low-volatility high-viscosity solvent is used, even if it is left standing for a certain period of time after coating, more specifically, usually, even if it is left standing for about 30 minutes at most, in a preferred embodiment, even if it is left standing for about 40 minutes at most, in a more preferred embodiment, even if it is left standing for about 50 minutes at most, in an even more preferred embodiment, even if it is left standing for about 1 hour at most, in a further preferred embodiment, even if it is left standing for about 2 hours at most, in an even further preferred embodiment, even if it is left standing for about 3 hours at most, the shape of the obtained coating film is difficult to change, and within the partition wall, variations in the shape of the organic functional layer due to differences in the timing of ink coating can be suppressed, and a substrate with an organic functional film having a good flatness and having an organic functional film can be efficiently produced. Furthermore, due to such characteristics, for example, in a mass production process, when the waiting time until the ink dries is long after all the ink coating on the panel is completed, or when the waiting time varies between panels, etc., variations in the shape of the organic functional layer due to the passage of time after all the ink coating is completed, or differences in the waiting time until the ink dries between the panels on which the ink coating is completed can also be suppressed.

[0283] In the present invention, as described above, it is possible to produce an organic functional film with good flatness. As the flatness index, it is usually 33% or less, in a preferred embodiment, 25% or less, in a more preferred embodiment, 19% or less, in an even more preferred embodiment, 13% or less, in a further preferred embodiment, 10% or less, and in a still further preferred embodiment, 6% or less, achieving excellent uniformity. The flatness index can be calculated by the formula |A - B| / B × 100 (%) where A (μm) is the film thickness at the edge of the partition (bank) and B (μm) is the film thickness at the center of the opening.

[0284] In the present invention, as described above, even if left standing for a certain period of time after coating, the shape of the resulting coating film hardly changes, and it is possible to stably produce an organic functional film with good flatness. As the standing stability index, it is usually 0.130, in a preferred embodiment, 0.110, in a more preferred embodiment, 0.090, in an even more preferred embodiment, 0.070, in a further preferred embodiment, 0.050, and in an even more preferred embodiment, 0.030, achieving high standing stability. The standing stability index can be calculated as the absolute value of the difference between the values obtained by calculating C / B for the charge transport thin film on which the coating film has been left standing and the charge transport thin film on which the coating film has not been left standing, where B (μm) is the film thickness at the center of the opening of the partition and C (μm) is the film thickness at the center between the outermost edge and the center of the opening of the partition.

[0285] The method for manufacturing a substrate with an organic functional film and an electronic device of the present invention is suitably used for manufacturing an electronic device in which a hole injection layer or a hole injection and transport layer is formed by an inkjet method as described above. In addition, it can also be used when forming a charge transport thin film by an inkjet method during the manufacture of other electronic devices such as organic optoelectronic conversion elements, organic thin-film solar cells, organic perovskite optoelectronic conversion elements, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic optical detectors, organic photoreceptors, organic field quenching elements, light-emitting electrochemistry cells, quantum dot light-emitting diodes, quantum lasers, organic laser diodes, and organic plasmonic light-emitting elements.

Example

[0286] Hereinafter, the present invention will be described more specifically with reference to synthesis examples, production examples, preparation examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0287] In this example, the equipment used is as follows. (1) Heating and decompression device: Berger-type vacuum oven BV-001 manufactured by Shibata Scientific Co., Ltd. (2) Inkjet device: Dedicated driver WAVE BUILDER (model number: PIJD-1) manufactured by Cluster Technology Co., Ltd., observation device inkjetlado with a camera, automatic stage Inkjet Designer, and inkjet head PIJ-25NSET (3) Film thickness measurement and surface shape measurement: Fine shape measuring machine Surf Coater ET-4000A manufactured by Kosaka Laboratory Ltd.

[0288] In this example, the reagents used are as follows. MMA: Methyl methacrylate HEMA: 2-Hydroxyethyl methacrylate HPMA: 4-Hydroxyphenyl methacrylate HPMA-QD: A compound synthesized by the condensation reaction of 1 mol of 4-hydroxyphenyl methacrylate and 1.1 mol of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride CHMI: N-cyclohexylmaleimide PFHMA: 2-(Perfluorohexyl)ethyl methacrylate MAA: Methacrylic acid AIBN: α,α'-Azobisisobutyronitrile QD1: A compound synthesized by the condensation reaction of 1 mol of α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene and 1.5 mol of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride GT-401: Tetra(3,4-epoxycyclohexylmethyl)butanetetracarboxylate modified ε-caprolactone (trade name: Epolide GT-401, manufactured by Daicel Corporation) PGME: Propylene glycol monomethyl ether PGMEA: Propylene glycol monomethyl ether acetate CHN: Cyclohexanone TMAH: Tetramethylammonium hydroxide

[0289] [1] Preparation of a substrate with partitions (banks) (1) Synthesis of an acrylic polymer [Synthesis Example 1] 10.0 g of MMA, 12.5 g of HEMA, 20.0 g of CHMI, 2.50 g of HPMA, 5.00 g of MAA, and 3.20 g of AIBN were dissolved in 79.8 g of PGME and reacted at 60 to 100 °C for 20 hours to obtain an acrylic polymer P1 solution (solid content concentration: 40% by mass). The Mn of the obtained acrylic polymer P1 was 3,700 and the Mw was 6,100.

[0290] [Synthesis Example 2] 5.0 g of HPMA, 7.84 g of PFHMA, 0.70 g of MAA, 1.46 g of CHMI, and 0.33 g of AIBN were dissolved in 51.3 g of CHN, and reacted at 110°C for 20 hours to obtain an acrylic polymer P2 solution (solid content concentration: 20% by mass). The Mn of the obtained acrylic polymer P2 was 4,300, and the Mw was 6,300.

[0291] The number average molecular weight (Mn) and weight average molecular weight (Mw) of acrylic polymers P1 and P2 were measured by gel permeation chromatography (GPC) under the following conditions. · Chromatograph: GPC apparatus LC-20AD manufactured by Shimadzu Corporation · Columns: Shodex KF-804L, 803L (both manufactured by Showa Denko K.K.) and TSK-GEL (manufactured by Tosoh Corporation) connected in series · Column temperature: 40°C · Detector: UV detector (254 nm) and RI detector · Eluent: Tetrahydrofuran · Column flow rate: 1 mL / min

[0292] (2) Production of positive photosensitive resin composition [Production Example 1] 5.04 g of the acrylic polymer P1 solution obtained in Synthesis Example 1, 0.05 g of the acrylic polymer P2 solution obtained in Synthesis Example 2, 0.40 g of QD1, 0.09 g of GT-401, and 6.42 g of PGMEA were mixed and stirred at room temperature for 3 hours to form a uniform solution, thereby obtaining a positive photosensitive resin composition.

[0293] (3) Fabrication of substrate with partition (bank) [Production Example 2] Using a spin coater, the positive photosensitive resin composition obtained in Production Example 1 was applied onto an ITO-glass substrate that had been ozone-cleaned for 10 minutes using UV-312 manufactured by Technovision Co., Ltd. After that, the substrate with the coating film was pre-baked (100 °C, 120 seconds) on a hot plate to form a thin film with a thickness of 1.2 μm. Through a mask with a pattern in which a large number of rectangles with a long side of 200 μm and a short side of 100 μm were drawn on this thin film, ultraviolet light with a wavelength of 365 nm was used to expose it at 175 mJ / cm 2 2. Then, the thin film was immersed in a 1.0 mass% TMAH aqueous solution for 120 seconds for development, and then the thin film was washed with running water using ultrapure water for 20 seconds. Next, the thin film with the rectangular pattern (opening) formed was post-baked (230 °C, 30 minutes) to be cured, and a substrate with partitions was produced.

[0294] [2] Synthesis of Compound [Production Example 3-1] 500 g of an aqueous dispersion of a polythiophene derivative (solid content concentration: 0.6 mass%) that is a polymer containing a repeating unit represented by the above formula (1a) was mixed with 0.9 g of triethylamine, and the resulting mixture was dried by rotary evaporation. Then, the obtained dried product was further dried in a vacuum oven at 50 °C overnight to obtain 4 g of a polythiophene derivative A in which an amine was added to the sulfonic acid group.

[0295] [Production Example 3-2] 2.00 g of the polythiophene derivative A obtained in Production Example 3-1 was dissolved in 100 mL of 28% aqueous ammonia (manufactured by Junsei Chemical Co., Ltd.), and the resulting solution was stirred overnight at room temperature. The resulting reaction mixture was subjected to reprecipitation treatment with 1,500 mL of acetone, and the precipitate was collected by filtration. The resulting precipitate was redissolved in 20 mL of water and 7.59 g of triethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and the mixture was stirred at 60 °C for 1 hour. After cooling the resulting reaction mixture, reprecipitation treatment was performed with a mixed solvent of 1,000 mL of isopropyl alcohol and 500 mL of acetone, and the precipitate was collected by filtration. The resulting precipitate was dried under reduced pressure at 50 °C for 1 hour to obtain 1.30 g of an amine-treated polythiophene derivative amine adduct.

[0296] [Production Example 3-3] According to the method described in International Publication No. 2006 / 025342, an arylsulfonic acid compound B represented by the formula (b-1) was synthesized.

[0297] [Chemical formula]

[0298] [3] Preparation of the composition for organic functional ink [Preparation Example 1] A propylene glycol solution containing 20% by mass of the arylsulfonic acid compound B was prepared. This solution was prepared by putting the arylsulfonic acid compound B into propylene glycol and stirring the resulting mixture at 50 °C for 2 hours using a hot stirrer.

[0299] [Preparation Example 2] Water, which is the dispersion medium of Snowtex (registered trademark) OS (silica aqueous dispersion sol with an average primary particle size of 8 to 11 nm) manufactured by Nissan Chemical Industries, Ltd., was replaced with tripropylene glycol to obtain a silica dispersion liquid having a silica concentration of 21.5% by mass with tripropylene glycol as the dispersion medium.

[0300] [4] Solvent volatility test The solvent residual rate of the organic solvent used was calculated by the following method. Weighed approximately 0.04 g of an organic solvent into an aluminum pan (φ5×5, Cat.No.8579, manufactured by Rigaku Corporation), and weighed the aluminum pan together with the organic solvent (mass Wt(B)). Then, after placing this aluminum pan on the heater in the heating and decompression apparatus, immediately covered the apparatus with a glass lid and decompressed the inside with a vacuum pump to perform a heating and decompression treatment for 1 minute. Note that the degree of decompression of the vacuum pump used for decompression was 1000 Pa after 10 seconds, 450 Pa after 20 seconds, 300 Pa after 30 seconds, 210 Pa after 40 seconds, 150 Pa after 50 seconds, and 140 Pa after 60 seconds. Also, the heater in the heating and decompression apparatus was set to 150 °C. After the heating and decompression treatment for 1 minute, immediately took out the aluminum pan and allowed it to cool, and weighed the aluminum pan together with the organic solvent (mass Wt(A)). Using the mass Wt(B) and mass Wt(A) obtained by the above method, the solvent residue rate (%) was calculated according to the formula [mass Wt(A) / mass Wt(B)]×100. The results are shown in Table 1.

[0301]

Table 1

[0302] The viscosity in Table 1 was measured at 25 °C using a TVE-25 viscometer manufactured by Toki Sangyo Co., Ltd.

[0303] [5] Preparation of Organic Functional Ink (Charge Transporting Varnish) [Example 1-1] Put 0.030 g of the amine-treated polythiophene derivative amine adduct obtained in Production Example 3-2 into 0.92 g of propylene glycol and 0.048 g of 2-ethylhexylamine, and stirred at 80 °C for 3 hours using a hot stirrer. To the obtained mixture, 1.07 g of tripropylene glycol, 4.25 g of propylene carbonate, 1.93 g of diethylene glycol mono isobutyl ether, and 0.49 g of 2-acetamidoethanol were added, and stirred at room temperature for 10 minutes using a stirrer. To the obtained mixture, 0.30 g of the solution obtained in Preparation Example 1 and 0.98 g of the silica dispersion obtained in Preparation Example 2 were added, and after further stirring at room temperature, the mixture was filtered through a PP syringe filter with a pore size of 0.2 μm to obtain a charge transporting varnish. The content ratio of 2-acetamidoethanol, which is a low-volatility high-viscosity solvent in the solvent constituting the varnish, is 5.0% by mass.

[0304] [Example 1-2] A charge transporting varnish was obtained in the same manner as in Example 1-1, except that N-(hydroxyethyl)lactamide was used instead of 2-acetamidoethanol. The content ratio of N-(hydroxyethyl)lactamide, which is a low-volatility high-viscosity solvent in the solvent constituting the varnish, is 5.0% by mass.

[0305] [Example 1-3] A charge transporting varnish was obtained in the same manner as in Example 1-1, except that the amount of the amine-treated polythiophene derivative amine adduct used was 0.030 g, the amount of propylene glycol used was 0.86 g, the amount of tripropylene glycol used was 0.97 g, the amount of propylene carbonate used was 4.02 g, the amount of diethylene glycol mono isobutyl ether used was 1.83 g, and the amount of 2-acetamidoethanol used was 0.97 g. The content ratio of 2-acetamidoethanol, which is a low-volatility high-viscosity solvent in the solvent constituting the varnish, is 10.0% by mass.

[0306] [Comparative Examples 1-1 to 1-4] Charge transporting varnishes were obtained in the same manner as in Example 1-1, except that 2,4-diethyl-1,5-pentanediol (Comparative Example 1-1), glycerin (Comparative Example 1-2), 3-methyl-1,5-pentanediol (Comparative Example 1-3), or 2-ethyl-1,3-hexanediol (Comparative Example 1-4) was used instead of 2-acetamidoethanol.

[0307] [Comparative Example 1-5] 0.030 g of the amine-treated polythiophene derivative amine adduct obtained in Production Example 3-2 was placed in 0.98 g of propylene glycol and 0.048 g of 2-ethylhexylamine, and stirred at 80 °C for 3 hours using a hot stirrer. To the resulting mixture, 1.16 g of tripropylene glycol, 4.47 g of propylene carbonate and 2.03 g of diethylene glycol mono-isobutyl ether were added, and the mixture was stirred at room temperature for 10 minutes using a stirrer. To the resulting mixture, 0.30 g of the solution obtained in Preparation Example 1 and 0.98 g of the silica dispersion obtained in Preparation Example 2 were added, and the mixture was further stirred at room temperature. Then, it was filtered through a PP syringe filter with a pore size of 0.2 μm to obtain a charge transporting varnish.

[0308] [6] Fabrication of a substrate with an organic functional film (charge transporting thin film) by inkjet coating and calculation of the flatness index Using an inkjet apparatus, in the rectangular opening (film formation region) on the substrate with a partition obtained in Production Example 2, the target film thickness of the charge transporting thin film at the center of the opening was set to 60 nm. Then, the charge transporting varnishes obtained in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-5 were ejected respectively. After the obtained coating film was dried under reduced pressure at a degree of vacuum of 10 Pa or less for 15 minutes, it was heated at 230 °C for 30 minutes using a hot plate to form a charge transporting thin film.

[0309] The cross-sectional shape and film thickness of each of the obtained charge transporting thin films were observed, and the degree of uniformity of the film within the partition, that is, the flatness index, was determined. The results are shown in Table 2. The flatness index was determined as |A - B| / B × 100 (%) where A (μm) is the film thickness at the edge of the opening partition (bank) and B (μm) is the film thickness at the center of the opening. The larger this value, the poorer the flatness. The values in Table 2 are for the major axis.

[0310]

Table 2

[0311] As shown in Table 2, in the organic functional film formed in the partition by inkjet coating using an organic functional ink containing an ink solvent containing 2 - acetamidoethanol and N - (hydroxyethyl) lactamide, which are low - volatility and high - viscosity solvents, at a predetermined ratio, the flatness index is lower than that of the organic functional film of the comparative example, and it can be seen that a charge - transporting thin film with good flatness is obtained.

[0312] [7] Fabrication of a substrate with an organic functional film (charge - transporting thin film) by inkjet coating with standing and confirmation of standing stability [Examples 3 - 1 to 3 - 2 and Comparative Example 3 - 1] Using an inkjet device on the rectangular opening (film - forming region) on the substrate with partitions obtained in Production Example 2, the target film thickness of the charge - transporting thin film at the center of the opening was set to 60 nm, and the charge - transporting varnishes obtained in Example 1 - 1, Example 1 - 3, and Comparative Example 1 - 5 were respectively ejected, and the obtained coating films were left standing for 20 minutes. After the standing coating films were dried under reduced pressure at a degree of vacuum of 10 Pa or less for 15 minutes, they were heated at 230 °C for 30 minutes using a hot plate to form charge - transporting thin films.

[0313] The shape and film thickness of the cross - section of each obtained charge - transporting thin film were observed, and the degree of change in the film shape, that is, the standing stability index, was determined as compared with the case where the coating film was not left standing (Example 2 - 1, Example 2 - 3, and Comparative Example 2 - 5). The results are shown in Table 3. The standing stability index was calculated as the absolute value of the difference between the C / B values obtained by calculating C / B for the charge - transporting thin film with the coating film left standing and the charge - transporting thin film without the coating film left standing, where the film thickness at the center of the opening was B (μm) and the film thickness at the center between the outermost edge of the opening and the center of the opening was C (μm). The larger this value, the poorer the standing stability. The values in Table 3 are for the major axis.

[0314]

Table 3

[0315] As shown in Table 3, in the case of an organic functional film formed in a partition by inkjet coating using an organic functional ink containing an ink solvent containing 2 - acetamidoethanol and N-(hydroxyethyl)lactamide, which are low - volatility and high - viscosity solvents, at a predetermined ratio, it can be seen that even when the coating film is left standing for a predetermined time, the retention stability is good and the change in film shape over time is small.

Claims

1. A method for manufacturing a substrate with an organic functional film, comprising a substrate, a partition wall defining an opening on the substrate, and an organic functional film within the partition wall, the method comprising: applying an organic functional ink containing an organic functional material and a solvent containing a low-volatility, high-viscosity solvent into the partition wall by an inkjet method; forming an organic functional film by removing the solvent from the organic functional ink applied within the partition wall by reducing the pressure; and wherein the viscosity of the low-volatility, high-viscosity solvent at 25°C is 200 mPa·s or more; when the pressure is reduced from normal pressure to 140 Pa in 1 minute while heating the low-volatility, high-viscosity solvent at 150°C, the residual ratio of the low-volatility, high-viscosity solvent is 80% by mass or more; and the content of the low-volatility, high-viscosity solvent in the solvent is 2.5% by mass or more. A method for manufacturing a substrate with an organic functional film, characterized by the above.

2. The method for manufacturing a substrate with an organic functional film according to Claim 1, wherein the low-volatility, high-viscosity solvent is a compound represented by the following formula (S1). 【Chemical 1】 (In the formula, R represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with a hydroxyl group or an alkoxy group having 1 to 10 carbon atoms, and R'represents a divalent hydrocarbon group.)

3. The method for manufacturing a substrate with an organic functional film according to Claim 2, wherein R represents an alkyl group having 1 to 5 carbon atoms, which may be substituted with a hydroxyl group, and R'represents an alkylene group having 1 to 5 carbon atoms.

4. The method for manufacturing a substrate with an organic functional film according to any one of Claims 1 to 3, wherein the low-volatility, high-viscosity solvent is at least one selected from 2-acetamidoethanol and N-(2-hydroxyethyl)lactamide.

5. The method for manufacturing a substrate with an organic functional film according to any one of Claims 1 to 4, wherein the content of the low-volatility, high-viscosity solvent in the solvent is 5.0% by mass or more.

6. The method for manufacturing a substrate with an organic functional film according to any one of Claims 1 to 5, wherein the solvent contains, as a solvent other than the low-volatility, high-viscosity solvent, only a solvent having a boiling point of 180°C or higher and being more volatile and having a lower viscosity than the low-volatility, high-viscosity solvent.

7. The method for manufacturing a substrate with an organic functional film according to Claim 6, wherein the solvent other than the low-volatility, high-viscosity solvent contains a hydrophilic glycol-based solvent in a proportion of 15 to 40% by mass.

8. The method for manufacturing a substrate with an organic functional film according to Claim 6, wherein the solvent other than the low-volatility, high-viscosity solvent contains a solvent having a surface tension at 25°C of 40 mN / m or less in a proportion of 30 to 50% by mass.

9. The method for manufacturing a substrate with an organic functional film according to claim 6, wherein the solvent other than the low-volatility high-viscosity solvent contains 60 to 85% by mass of a solvent having a viscosity of 10 mPa·s or less at 25°C.

10. The method for manufacturing a substrate with an organic functional film according to any one of claims 1 to 9, wherein the organic functional material is an arylamine derivative or a polythiophene derivative.

11. A method for manufacturing an electronic device, comprising a step of further forming an organic functional layer on a substrate with an organic functional film obtained by the manufacturing method according to any one of claims 1 to 10.

12. When manufacturing a substrate with an organic functional film having a substrate, a partition wall defining an opening on the substrate, and an organic functional film in the partition wall, an ink for an inkjet method applied by an inkjet method into the partition wall, comprising an organic functional material and a solvent containing a low-volatility high-viscosity solvent, wherein the viscosity of the low-volatility high-viscosity solvent at 25°C is 200 mPa·s or more, when the pressure is reduced from normal pressure to 140 Pa in 1 minute while heating the low-volatility high-viscosity solvent at 150°C, the residual ratio of the low-volatility high-viscosity solvent is 80% by mass or more, and the content of the low-volatility high-viscosity solvent in the solvent is 2.5% by mass or more. An ink for an inkjet method characterized by this.

13. The ink for an inkjet method according to claim 12, wherein the low-volatility high-viscosity solvent is a compound represented by the following formula (S1). 【Chemical 2】 (In the formula, R represents a monovalent hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a hydroxyl group or an alkoxy group having 1 to 10 carbon atoms, and R'represents a divalent hydrocarbon group.)

14. The ink for an inkjet method according to claim 13, wherein R represents an alkyl group having 1 to 5 carbon atoms which may be substituted with a hydroxyl group, and R'represents an alkylene group having 1 to 5 carbon atoms.

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