阅读说明：本技术 膜的制造方法、有机el元件的制造方法、以及用于制造膜的墨液组合物组 (Method for producing film, method for producing organic EL element, and ink composition set for producing film ) 是由 山下和贵 仓田知己 于 2019-06-28 设计创作，主要内容包括：一种膜的制造方法,具备：墨液准备工序,准备包含相互不同的固体成分物质且试验膜的平坦度R均为60％以上的第一墨液组合物和第二墨液组合物；第一涂布工序,在所述基板的第一区域涂布所述第一墨液组合物而形成第一涂布层；第二涂布工序,在所述基板的与所述第一区域不同的第二区域涂布所述第二墨液组合物而形成第二涂布层；和干燥工序,在所述第一涂布工序和所述第二涂布工序之后,将所述基板放入干燥机内,使所述第一涂布层和所述第二涂布层干燥而形成第一膜和第二膜,在所述墨液准备工序中,以第一主溶剂与第二主溶剂种类相同的方式准备所述第一墨液组合物和所述第二墨液组合物。(A method for producing a film, comprising: an ink preparation step of preparing a first ink composition and a second ink composition which contain solid component substances different from each other and in which the test film has a flatness R of 60% or more; a first coating step of coating the first ink composition on a first region of the substrate to form a first coating layer; a second coating step of coating a second region of the substrate different from the first region with the second ink composition to form a second coating layer; and a drying step of placing the substrate in a dryer after the first coating step and the second coating step, and drying the first coating layer and the second coating layer to form a first film and a second film, wherein in the ink preparation step, the first ink composition and the second ink composition are prepared so that the first main solvent and the second main solvent are the same in type.)

1. A method for manufacturing a film, wherein a first film and a second film are manufactured on a surface of a substrate, the method comprising:

an ink preparation step of preparing a first ink composition and a second ink composition which contain solid component substances different from each other and in which the test film has a flatness R of 60% or more;

a first coating step of coating the first ink composition on a first region of the substrate to form a first coating layer;

a second coating step of coating a second region of the substrate different from the first region with the second ink composition to form a second coating layer; and

a drying step of placing the substrate in a dryer after the first coating step and the second coating step to dry the first coating layer and the second coating layer to form a first film and a second film,

in the ink preparation step, the first ink composition and the second ink composition are prepared so that a first main solvent having a content of 5 mass% or more with respect to the total amount of solvents of the first ink composition and a second main solvent having a content of 5 mass% or more with respect to the total amount of solvents of the second ink composition are of the same type,

the test film is a film obtained by applying an ink composition to a test substrate to form a test coating layer, placing the test substrate in the dryer, and drying the test coating layer under drying conditions in the drying step,

in the test film, the area of the total region is represented by A, and the minimum film thickness is represented by T_minWhen the film thickness is set to be T_minB represents the area of the region of +10nm or less, and the flatness R is calculated by the following equation,

R＝(B/A)×100

the flatness R is expressed in%, the area A of the total region is expressed in%, and the film thickness is expressed in T_minThe unit of the area B of the region of +10nm or less is [ mu ] m²Said minimum film thickness T_minIn nm.

2. The method for producing a film according to claim 1,

in the ink preparation step, the first ink composition and the second ink composition are prepared so that the first main solvent and the second main solvent are the same in kind and have different content ratios of the respective components.

3. The method for producing a film according to claim 1 or 2,

the first main solvent and the second main solvent contain a compound represented by formula (1),

in the formula (1), R¹Represents an alkyl group having 10 to 12 carbon atoms.

4. The method for producing a film according to claim 1 or 2,

the first main solvent and the second main solvent contain an aromatic hydrocarbon other than the compound represented by formula (1),

in the formula (1), R¹Represents an alkyl group having 10 to 12 carbon atoms.

5. The method of manufacturing a film according to claim 4,

the aromatic hydrocarbon is selected from the group consisting of pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, cyclohexylbenzene, and tetrahydronaphthalene.

6. The method for producing a film according to claim 1 or 2,

the first main solvent and the second main solvent include an aromatic ether.

7. The method of manufacturing a film according to claim 6,

the aromatic ether is selected from the group consisting of methyl anisole, dimethyl anisole, ethyl anisole, butyl phenyl ether, butyl anisole, pentyl anisole, hexyl anisole, heptyl anisole, octyl anisole and phenoxy toluene.

8. The method for producing a film according to claim 1 or 2,

the first ink composition and the second ink composition contain mutually different polymer compounds.

9. The method of manufacturing a film according to claim 8,

the polymer compound is a luminescent compound.

10. A method for producing an organic EL element, comprising a step of producing a film by the method for producing a film according to claim 1 or 2.

11. An ink composition set for use in the method for producing a film according to claim 1 or 2, the ink composition set comprising at least the first ink composition and the second ink composition.

Technical Field

The present invention relates to a method for producing a film and a method for producing an organic EL element, and also relates to an ink composition set for producing a film.

Background

Since an organic EL element (organic electroluminescence element) has high luminous efficiency and low driving voltage, it can be suitably used for displays and lighting. The organic EL element includes organic layers such as a light-emitting layer and a charge transport layer. By using a composition for an organic EL element in which a polymer compound such as an organic EL material (organic electroluminescent material) is dissolved in a solvent, an organic layer can be formed by a discharge-type coating method typified by an inkjet printing method.

International publication No. 2013/088744 describes that variation in cross-sectional shape between pixels can be suppressed by adjusting the application timing of two or more inks.

Disclosure of Invention

The present inventors have obtained the following findings when a film is produced using two or more ink compositions: when the ink composition is dried at one time, the flatness of the film varies depending on the type of the ink composition. However, when a film is produced using two or more ink compositions, drying steps become complicated if different drying conditions are adopted depending on the type of ink composition.

An object of the present invention is to provide a method for producing a film, a method for producing an organic EL element, and an ink composition set for producing a film, which can produce two or more films having excellent flatness even when a film is produced by one-time drying using two or more ink compositions.

The present invention provides a method for producing a film, a method for producing an organic EL element, and an ink composition set for producing a film, as described below.

[1] A method for manufacturing a film, wherein a first film and a second film are manufactured on a surface of a substrate, the method comprising:

an ink preparation step of preparing a first ink composition and a second ink composition which contain solid component substances different from each other and in which the test film has a flatness R of 60% or more;

a first coating step of coating the first ink composition on a first region of the substrate to form a first coating layer;

a second coating step of coating a second region of the substrate different from the first region with the second ink composition to form a second coating layer; and

a drying step of, after the first coating step and the second coating step, placing the substrate in a dryer to dry the first coating layer and the second coating layer to form a first film and a second film,

in the ink preparation step, the first ink composition and the second ink composition are prepared so that a first main solvent having a content of 5 mass% or more relative to the total amount of solvents of the first ink composition and a second main solvent having a content of 5 mass% or more relative to the total amount of solvents of the second ink composition are of the same type,

the test film is a film obtained by applying an ink composition to a test substrate to form a test coating layer, placing the test substrate in the dryer, and drying the test coating layer under the drying conditions in the drying step,

in the test film, the area of the total region is defined as A (μm)²) Setting the minimum film thickness as T_min(nm) the film thickness is T_minThe area of the region of +10nm or less is B (μm)²) The flatness R (%) is calculated by the following formula,

R＝(B/A)×100。

[2] the method for producing a film according to [1], wherein in the ink preparation step, the first ink composition and the second ink composition are prepared so that the first main solvent and the second main solvent are the same in kind and different in content ratio of each component.

[3] The method for producing a film according to [1] or [2], wherein the first main solvent and the second main solvent contain a compound represented by formula (1).

[ in the formula (1), R¹Represents an alkyl group having 10 to 12 carbon atoms.]

[4] The method for producing a membrane according to any one of [1] to [3], wherein the first main solvent and the second main solvent contain an aromatic hydrocarbon other than the compound represented by formula (1).

[ in the formula (1), R¹Represents an alkyl group having 10 to 12 carbon atoms.]

[5] The method for producing a membrane according to [4], wherein the aromatic hydrocarbon is selected from the group consisting of pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, cyclohexylbenzene, and tetrahydronaphthalene.

[6] The method for producing a film according to any one of [1] to [5], wherein the first main solvent and the second main solvent contain an aromatic ether.

[7] The method for producing a film according to [6], wherein the aromatic ether is selected from the group consisting of methyl anisole, dimethyl anisole, ethyl anisole, butyl phenyl ether, butyl anisole, pentyl anisole, hexyl anisole, heptyl anisole, octyl anisole and phenoxy toluene.

[8] The method for producing a film according to any one of [1] to [7], wherein the first ink composition and the second ink composition contain different polymer compounds.

[9] The method for producing a film according to [8], wherein the polymer compound is a luminescent compound.

[10] A method for manufacturing an organic EL element, comprising a step of manufacturing a film by the method for manufacturing a film according to any one of [1] to [9 ].

[11] An ink composition set used in the method for producing a film according to any one of [1] to [9], the ink composition set including at least the first ink composition and the second ink composition.

The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention, which is to be read in connection with the accompanying drawings.

Drawings

Fig. 1 is a view schematically showing a coating step in the production method according to the present invention.

Fig. 2 is a plan view showing an example of the substrate after the coating step in the manufacturing method according to the present invention.

FIG. 3 is a diagram showing (a) the cross-sectional shape of the first membrane of example 1 and (b) the cross-sectional shape of the test membrane.

FIG. 4 is a diagram showing (a) the cross-sectional shape of the second membrane of example 1 and (b) the cross-sectional shape of the test membrane.

FIG. 5 is a diagram showing (a) the cross-sectional shape of the first membrane of example 2 and (b) the cross-sectional shape of the test membrane.

FIG. 6 is a diagram showing (a) the sectional shape of the second membrane of example 2 and (b) the sectional shape of the test membrane.

Fig. 7 is a view showing (a) the sectional shape of the first membrane of comparative example 1 and (b) the sectional shape of the test membrane.

Fig. 8 is a diagram showing (a) a cross-sectional shape of the second membrane of comparative example 1 and (b) a cross-sectional shape of the test membrane.

Description of the symbols

1 substrate, 21 first head, 41 first region, 42 second region, 43 partition wall.

Detailed Description

[ method for producing film ]

The present invention relates to a film manufacturing method for manufacturing a first film and a second film on a surface of a substrate, including:

an ink preparation step of preparing a first ink composition and a second ink composition which contain solid component substances different from each other and in which the test film has a flatness R of 60% or more;

a first coating step of coating the first ink composition on a first region of the substrate to form a first coating layer;

a second coating step of coating a second region of the substrate different from the first region with the second ink composition to form a second coating layer; and

and a drying step of, after the first coating step and the second coating step, placing the substrate in a dryer and drying the first coating layer and the second coating layer to form a first film and a second film.

The method for producing a film according to the present invention relates to a method for producing a film having at least two kinds of films (a first film and a second film) on a surface of a substrate, and also includes a method for producing a film having three or more kinds of films on a surface of a substrate.

In the ink preparation step, the first ink composition and the second ink composition are prepared so that a first main solvent having a content of 5 mass% or more with respect to the total amount of solvents of the first ink composition and a second main solvent having a content of 5 mass% or more with respect to the total amount of solvents of the second ink composition are the same type.

[ base plate ]

The substrate has a first region and a second region different from the first region. When the film manufactured by the manufacturing method according to the present invention is used as an element of an organic EL element, the first region corresponds to a first pixel of the organic EL element, and the second region corresponds to a second pixel of the organic EL element. In this case, as one aspect, the first region and the second region are divided by the partition wall on the substrate, and the planar shape of each region is a circle, an ellipse, an oval, a rectangle, or the like. The substrate may be any substrate that does not chemically change when the organic layer is formed, and examples of the substrate include substrates made of materials such as glass, plastic, and silicon.

[ first coating step and second coating step ]

An example of the first coating step and the second coating step performed by the inkjet printing apparatus will be described with reference to the drawings. Fig. 1 shows an example of the first coating step. In fig. 1, a first coating step of forming a first coating layer using a first ink composition in first regions 41 is performed using a substrate 1 having the first regions 41 and second regions 42 alternately arranged. The inkjet printing apparatus used in the first and second coating steps includes a first head that ejects a first ink composition and a second head that ejects a second ink composition. The first coating step may be performed using a first inkjet printing device having a first head that ejects the first ink composition, and the second coating step may be performed using a second inkjet printing device having a second head that ejects the second ink composition.

As shown in fig. 1, in the first coating step, the substrate 1 is conveyed below the first head 21, droplets of the first ink composition are ejected from the plurality of ejection nozzles at positions of the first head 21 corresponding to the first regions 41, and the droplets are dropped onto the first regions 41 to form the first coating layer. In the apparatus shown in fig. 1, the substrate 1 is conveyed in the direction Dd orthogonal to the arrangement direction of the first heads 21, and at the same time, the first ink composition is dropped by the exactly required number of droplets in the first area 41 of the first row (the direction parallel to the arrangement direction of the first heads 21) to form a first coating layer, and then the exactly required number of droplets is dropped in the first area 41 of the next row to form a subsequent first coating layer. By continuously performing such operations, a first coating step of forming a first coating layer in the first region 41 is performed. When the number of pixels to be coated existing in one row on the substrate 1 is larger than the number of discharge nozzles of the first head, all the pixels to be coated are coated by a method such as moving the first head 21 in the arrangement direction or moving the substrate 1 in the arrangement direction of the first head 21. The conveyance of the substrate 1 in the direction Dd orthogonal to the arrangement direction of the first heads 21 may be reciprocated along with the conveyance in the direction opposite to the direction Dd. In this case, the ejection from the first head 21 may be performed in both the forward and backward directions of the reciprocating movement, or may be performed only in the forward direction or only in the backward direction.

After the first coating step, a second coating step is performed. In the second coating step, similarly to the first coating step, droplets of the second ink composition are discharged from the plurality of discharge nozzles in the second head at positions corresponding to the second regions 42, and the droplets are dropped onto the second regions 42 to form a second coating layer.

Fig. 2 schematically shows the upper surface of the substrate 1 after the first coating step and the second coating step are completed. As shown in fig. 2, a first coating layer is formed in the first region 41, and a second coating layer is formed in the second region 42. In the present embodiment, only the case where two ink compositions are used has been described, but when three or more ink compositions are used, three or more coating layers can be formed by repeating the same coating step.

As an apparatus for applying ink used in the first application step and the second application step, an inkjet printing apparatus shown in fig. 1 and the like can be mentioned. The first coating step and the second coating step are not limited to the inkjet printing method using the inkjet printing apparatus, and a nozzle printing method, a flexographic printing method, an offset printing method (オ フ セ ッ ト printing method), or the like can be used.

[ drying Process ]

In the drying step, the substrate on which the first coating layer and the second coating layer are formed is placed in a dryer and placed in a predetermined atmosphere, whereby the first coating layer is dried to form a first film and the second coating layer is dried to form a second film.

In the drying step, the solvent evaporates from the first ink composition forming the first coating layer and the second ink composition forming the second coating layer, and is cured to form the first film and the second film.

From the viewpoint of shortening the time of the drying step, the drying step is preferably performed under reduced pressure. After the substrate is placed in the dryer, the pressure in the dryer is gradually or stepwise decreased from the atmospheric pressure, thereby adjusting the pressure in the drying step. The pressure reduction rate from atmospheric pressure to 1000Pa is preferably 1000 Pa/sec to 30000 Pa/sec, for example. The temperature in the dryer (more specifically, on the stage on which the substrate 1 is placed) is preferably controlled to be maintained in a range of, for example, 20 ℃ to 100 ℃.

[ ink preparation Process ]

In the ink preparation step, a first ink composition and a second ink composition are prepared. The first ink composition and the second ink composition contain different solid components, and the flatness R of the test film is 60% or more.

The test membrane was set as: the ink composition is applied to a test substrate to form a test coating layer, the test substrate is placed in the same dryer as the drying step, and the test coating layer is dried under the drying conditions in the drying step.

The flatness R (%) was set as: in the test film, the area of the total region was defined as A (μm)²) Setting the minimum film thickness as T_min(nm) the film thickness is T_minThe area of the region of +10nm or less is B (μm)²) The value calculated by the following equation,

R＝(B/A)×100。

note that the flatness R (%) of the first film and the second film was also calculated in the same manner as the flatness R (%) of the test film.

The present inventors have found the following problems: even when an ink composition having a flatness R of 60% or more of a test film is prepared in an ink preparation step, when two or more ink compositions are used in a drying step and the ink composition is dried at one time, the flatness R may decrease to less than 60% depending on the film.

The inventors have found the following insight, namely: in the ink preparation step, the first ink composition and the second ink composition are prepared so that the first main solvent having a content of 5 mass% or more relative to the total amount of the solvent of the first ink composition and the second main solvent having a content of 5 mass% or more relative to the total amount of the solvent of the second ink composition are of the same type, whereby the first film and the second film both have excellent flatness R even when the first film is once dried in the drying step, and the present invention has been completed. According to the present invention, even when the first film and the second film are once dried in the drying step, both the first film and the second film can be manufactured so as to have the flatness R of 60% or more.

In the ink preparation step, the first ink composition and the second ink composition are preferably prepared so that the first main solvent and the second main solvent are the same in kind and have different content ratios of the respective components. The first main solvent and the second main solvent are the same in kind, and for example, correspond to a case where they are each composed of only the solvent a, the solvent b, and the solvent c. The difference in the content ratio of each component of the first main solvent and the second main solvent means, for example, a ratio "content of the solvent a: content of solvent b: the content of the solvent c "is different.

The first ink composition and the second ink composition contain a "solid component (a)" and a "solvent (B)". Terms used in common in the present specification have the following meanings unless otherwise specified.

The term "polymer compound" means a compound having a molecular weight distribution and a weight average molecular weight in terms of polystyrene of 1X 10³～1×10⁸The polymer of (1). The polymer compound may be any of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer, or may be in other forms. When the polymerizable group remains as it is, there is a possibility that the light-emitting characteristics or the luminance lifetime may be reduced when the polymer compound is used for manufacturing a light-emitting element, and therefore, the terminal group of the polymer compound is preferably a stable group. The terminal group is preferably a group conjugated to the main chain, and examples thereof include a group bonded to an aryl group or a monovalent heterocyclic group via a carbon-carbon bond.

The term "low-molecular-weight compound" means a compound having no molecular weight distribution and a molecular weight of 1X 10⁴The following compounds.

The "main solvent" means a solvent contained in an amount of 5% by mass or more relative to the total amount of the solvent (B). The "main solvent" is a generic term including a "first main solvent" which is a main solvent in the first ink composition and a "second main solvent" which is a main solvent in the second ink composition.

The "ink composition" is a generic term including "first ink composition" and "second ink composition".

< solvent (B) >

The solvent (B) contained in each ink composition preferably contains at least two main solvents. As the main solvent, a solvent (b1) which is a compound represented by formula (1), a solvent (b2) which is an aromatic hydrocarbon other than the compound represented by formula (1), and a solvent (b3) which is an aromatic ether are suitable. The "species" referred to as "at least two" herein means a species as a compound, and does not mean a species of a class in which the solvent (b1), the solvent (b2), and the solvent (b3) are each classified. Therefore, for example, when only two different compounds belonging to the solvent (B1) are contained as the main solvents in the solvent (B), the case where at least two main solvents are contained is also considered. The solvent (B1), the solvent (B2), and the solvent (B3) may be contained as the main solvent in the solvent (B), or may be contained as a solvent other than the main solvent, that is, a solvent having a content of less than 5% by mass. The solvent (B) contained in each ink composition may contain only one kind of main solvent.

Solvent (b1)

The solvent (b1) is represented by formula (1).

[ in the formula (1), R¹Represents an alkyl group having 10 to 12 carbon atoms.]

R¹The alkyl group having 10 to 12 carbon atoms may be a straight-chain alkyl group or a branched-chain alkyl group, and is preferably a straight-chain alkyl group.

R¹The alkyl group having 10 carbon atoms is preferable, and the straight-chain alkyl group having 10 carbon atoms is more preferable.

As R¹Examples of the alkyl group having 10 to 12 carbon atoms include straight-chain alkyl groups such as decyl group, undecyl group, and dodecyl group; branched alkyl groups such as methylnonyl, methyldecyl, methylundecyl, dimethyloctyl, dimethylnonyl, dimethyldecyl, trimethylheptyl, trimethyloctyl, trimethylnonyl, tetramethylhexyl, tetramethylheptyl, tetramethyloctyl, pentamethylhexyl, pentamethylheptyl, and hexamethylhexyl, with decyl, undecyl, dodecyl, tetramethyloctyl, pentamethylhexyl, and the like being preferredMethylheptyl or hexamethylhexyl, more preferably decyl, undecyl or dodecyl, further preferably 1-decyl, 2-decyl, 3-decyl, 4-decyl, 5-decyl, 1-undecyl, 2-undecyl, 3-undecyl, 1-dodecyl, 2-dodecyl or 3-dodecyl, particularly preferably 1-decyl, 2-decyl or 3-decyl.

Examples of the solvent (b1) include: decyl benzene (boiling point: 293 ℃ C.), dodecyl benzene (boiling point: 331 ℃ C.).

Each ink composition may contain a single solvent (b1), or may contain two or more solvents (b 1).

Solvent (b2)

The solvent (b2) is an aromatic hydrocarbon other than the compound represented by formula (1).

The solvent (b2) preferably has 6 to 15 total carbon atoms, more preferably 7 to 15 total carbon atoms.

The solvent (b2) preferably contains 1 benzene ring, and more preferably a benzene substituted with an alkyl group or a cycloalkyl group having 7 to 15 total carbon atoms.

Examples of the solvent (b2) include: toluene, xylene, trimethylbenzene, ethylbenzene, diethylbenzene, ethylmethylbenzene, propylbenzene, butylbenzene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, dipropylbenzene, cyclohexylbenzene, tetrahydronaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, cyclohexylbenzene, or tetrahydronaphthalene are preferable, heptylbenzene, octylbenzene, nonylbenzene, cyclohexylbenzene, or tetrahydronaphthalene are more preferable, heptylbenzene, octylbenzene, nonylbenzene, cyclohexylbenzene, or tetrahydronaphthalene are further preferable, heptylbenzene, octylbenzene, nonylbenzene, or cyclohexylbenzene are further preferable, and 1-heptylbenzene, 1-octylbenzene, 1-nonylbenzene, and cyclohexylbenzene are particularly preferable, since the flatness of the film formed using the composition of the present invention is more excellent.

Each ink composition may contain a single solvent (b2), or may contain two or more solvents (b 2).

Solvent (b3)

The solvent (b3) is an aromatic ether.

The solvent (b3) preferably has 7 to 15 total carbon atoms.

Examples of the solvent (b3) include alkyl aryl ethers having 7 to 15 total carbon atoms and an aryl moiety which may be substituted with an alkyl group, and diaryl ethers having 12 to 15 total carbon atoms and an alkyl group, and preferably alkyl phenyl ethers having 7 to 15 total carbon atoms and a phenyl moiety which may be substituted with an alkyl group, and diphenyl ethers having 12 to 15 total carbon atoms and an alkyl group.

Examples of the solvent (b3) include anisole, ethylphenyl ether, methylanisole, dimethylanisole, ethylanisole, butylphenyl ether, butylanisole, pentylanisole, hexylanisole, heptylanisole, octylanisole, 1-methoxynaphthalene, diphenyl ether, phenoxytoluene, of these, methyl anisole, dimethyl anisole, ethyl anisole, butyl phenyl ether, butyl anisole, pentyl anisole, hexyl anisole, heptyl anisole, octyl anisole or phenoxy toluene is preferable, 2-methyl anisole, 3-methyl anisole, 4-methyl anisole, 2, 5-dimethyl anisole, 2-ethyl anisole, 4-ethyl anisole or 3-phenoxy toluene is more preferable, and 2-methyl anisole, 3-methyl anisole, 4-methyl anisole or 3-phenoxy toluene is further preferable.

The ink composition may contain a single solvent (b3) or may contain two or more solvents (b 3).

Other solvents

Each ink composition may contain a solvent (hereinafter also referred to as "solvent (b 4)") other than solvent (b1), solvent (b2), and solvent (b 3). The solvent (B4) may be contained as a main solvent in a content of 5 mass% or more relative to the total amount of the solvent (B), or may be contained as a solvent other than the main solvent in a content of less than 5 mass% relative to the total amount of the solvent (B).

Examples of the solvent (b4) include an aliphatic hydrocarbon solvent, a monohydric alcohol solvent, a polyhydric alcohol solvent, an ester solvent, a ketone solvent, an aliphatic ether solvent, a nitrogen atom-containing solvent, and a sulfur atom-containing solvent.

Each ink composition may contain a single solvent (b4) or may contain two or more solvents (b 4).

Solvents with the highest boiling points

In each ink composition, the highest boiling point solvent having the highest boiling point among the main solvents preferably has a boiling point of 200 ℃ or higher under atmospheric pressure. The boiling point of the highest boiling solvent at atmospheric pressure is preferably 350 ℃ or lower. The highest boiling point solvent is preferably the above-mentioned solvent (b 1). The difference between the boiling point of the highest boiling point solvent at atmospheric pressure and the boiling point of the second highest boiling point solvent in the main solvent at atmospheric pressure is preferably 10 ℃ or more, more preferably 20 ℃ or more, and still more preferably 30 ℃ or more. The concentration of the highest boiling point solvent is preferably 5 mass% or more and 60 mass% or less, and more preferably 10 mass% or more and 50 mass% or less, with respect to the total amount of the main solvent.

Composition ratio of solvent

In one example of the solvent (B), the main solvent includes solvent (B1), solvent (B2), and solvent (B3), and the content of the solvent (B1): m1 (mass), content of solvent (b 2): m2 (mass) and content of solvent (b 3): m3 (mass) is preferably satisfied by the following relational expressions (1) and (2) because the flatness of a test film formed using the ink composition can be improved.

0.05≤m1/(m1+m2+m3)≤0.60 (1)

0.10≤m2/(m2+m3)≤0.90 (2)

When two or more solvents (b1) are contained, m1 represents the total content of the solvents (b 1). When two or more solvents (b2) are contained, m2 represents the total content of the solvents (b 2). When two or more solvents (b3) are contained, m3 represents the total content of the solvents (b 3).

If the content is less than 5% by mass relative to the total amount of the solvent (B), the solvent (B) may also contain a solvent having a boiling point higher than the highest boiling point solvent. In the case of a solvent having a boiling point higher than the highest boiling point solvent, the amount of the solvent (B) is preferably less than 1% by mass of the total amount of the solvents (a) and less than 5% by mass of the total amount of the solvents (a).

< solid component (A) >)

The solid component (a) contained in each ink composition preferably contains a polymer compound, and may contain a low-molecular compound. When the solid component (a) contains a low-molecular compound, the low-molecular compound may be a light-emitting material. When the low-molecular compound is a light-emitting material, an iridium complex is preferable from the viewpoint of having excellent light-emitting characteristics. The iridium complex may be contained not as a low molecular weight compound but as a high molecular weight compound containing a structural unit having the structure of an iridium complex (that is, a structural unit having a group in which 1 or more hydrogen atoms directly bonded to a carbon atom or a hetero atom constituting the iridium complex are removed).

Description of common terms

The terms used in common hereinafter have the following meanings unless otherwise specified.

Me represents a methyl group, Et represents an ethyl group, Bu represents a butyl group, i-Pr represents an isopropyl group, and t-Bu represents a tert-butyl group.

The hydrogen atom may be a deuterium atom or a protium atom.

In the formula representing the metal complex, the solid line representing the bond with the central metal means a covalent bond or a coordinate bond.

The term "structural unit" means that 1 or more units are present in the polymer compound.

The "alkyl group" may be any of a straight chain and a branched chain. The number of carbon atoms of the linear alkyl group is not limited to the number of carbon atoms of the substituent, and is usually 1 to 50, preferably 3 to 30, and more preferably 4 to 20. The number of carbon atoms of the branched alkyl group is not limited to the number of carbon atoms of the substituent, and is usually 3 to 50, preferably 3 to 30, and more preferably 4 to 20.

The alkyl group may have a substituent, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a 2-ethylbutyl group, a hexyl group, a heptyl group, an octyl group, a 2-butyl group, a 2-ethylhexyl group, a 3-propylheptyl group, a decyl group, a3, 7-dimethyloctyl group, a 2-ethyloctyl group, a 2-hexyldecyl group, a dodecyl group, and a group in which a hydrogen atom in these groups is substituted with a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom, and the like, and examples of the alkyl group include a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, a perfluorooctyl group, a 3-phenylpropyl group, a 3.

The number of carbon atoms of the "cycloalkyl group" is not limited to the number of carbon atoms of the substituent, and is usually 3 to 50, preferably 3 to 30, and more preferably 4 to 20.

The cycloalkyl group may have a substituent, and examples of the cycloalkyl group include a cyclohexyl group, a cyclohexylmethyl group, and a cyclohexylethyl group.

The "aryl group" refers to an atomic group remaining after 1 hydrogen atom directly bonded to a carbon atom constituting a ring is removed from an aromatic hydrocarbon. The number of carbon atoms of the aryl group is not limited to the number of carbon atoms of the substituent, and is usually 6 to 60, preferably 6 to 20, and more preferably 6 to 10.

The aryl group may have a substituent, and examples of the aryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenyl group, a 2-fluorenyl group, a 3-fluorenyl group, a 4-fluorenyl group, a 2-phenylphenyl group, a 3-phenylphenyl group, a 4-phenylphenyl group, and groups in which a hydrogen atom in these groups is substituted by an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom, and the like.

The "alkoxy group" may be any of a straight chain and a branched chain. The number of carbon atoms of the linear alkoxy group is not limited to the number of carbon atoms of the substituent, and is usually 1 to 40, preferably 4 to 10. The number of carbon atoms of the branched alkoxy group is not limited to the number of carbon atoms of the substituent, and is usually 3 to 40, preferably 4 to 10.

The alkoxy group may have a substituent, and examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, a3, 7-dimethyloctyloxy group, a lauryloxy group, and groups obtained by substituting a hydrogen atom in these groups with a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom, or the like.

The number of carbon atoms of the "cycloalkoxy group" is not limited to the number of carbon atoms of the substituent, and is usually 3 to 40, preferably 4 to 10. The cycloalkoxy group may have a substituent, and examples of the cycloalkoxy group include a cyclohexyloxy group.

The number of carbon atoms of the "aryloxy group" is not limited to the number of carbon atoms of the substituent, and is usually 6 to 60, preferably 6 to 48. The aryloxy group may have a substituent, and examples of the aryloxy group include a phenoxy group, a 1-naphthoxy group, a 2-naphthoxy group, a 1-anthracenoxy group, a 9-anthracenoxy group, a 1-pyrenyloxy group, and groups obtained by substituting a hydrogen atom in these groups with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, a fluorine atom, or the like.

The "p-valent heterocyclic group" (p represents an integer of 1 or more) means an atomic group remaining after p hydrogen atoms among hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting a ring are removed from a heterocyclic compound. Among the p-valent heterocyclic groups, preferred is a "p-valent aromatic heterocyclic group" which is an atomic group obtained by removing p hydrogen atoms from an aromatic heterocyclic compound among hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting the ring.

The "aromatic heterocyclic compound" refers to a compound in which a heterocyclic ring itself exhibits aromaticity, such as oxadiazole, thiadiazole, thiazole, oxazole, thiophene, pyrrole, phosphole, furan, pyridine, pyrazine, pyrimidine, triazine, pyridazine, quinoline, isoquinoline, carbazole, dibenzophosphole, and the like, and a compound in which an aromatic ring is fused to a heterocyclic ring, although the heterocyclic ring itself does not exhibit aromaticity, such as phenoxazine, phenothiazine, dibenzoborole, dibenzosilole, benzopyran, and the like.

The number of carbon atoms of the monovalent heterocyclic group is not limited to the number of carbon atoms of the substituent, and is usually 2 to 60, preferably 4 to 20.

The monovalent heterocyclic group may have a substituent, and examples of the monovalent heterocyclic group include a thienyl group, a pyrrolyl group, a furyl group, a pyridyl group, a piperidyl group, a quinolyl group, an isoquinolyl group, a pyrimidyl group, a triazinyl group, and those in which a hydrogen atom is substituted with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, or the like.

"halogen atom" means a fluorine atom, chlorine atom, bromine atom or iodine atom.

The "amino group" may have a substituent, and is preferably a substituted amino group. The substituent of the amino group is preferably an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group. Examples of the substituted amino group include a dialkylamino group, a bicycloalkylamino group, and a diarylamino group. Examples of the amino group include a dimethylamino group, a diethylamino group, a diphenylamino group, a bis (4-methylphenyl) amino group, a bis (4-tert-butylphenyl) amino group, and a bis (3, 5-di-tert-butylphenyl) amino group.

The "alkenyl group" may be any of a straight chain and a branched chain. The number of carbon atoms of the linear alkenyl group is not limited to the number of carbon atoms of the substituent, and is usually 2 to 30, preferably 3 to 20. The number of carbon atoms of the branched alkenyl group is not limited to the number of carbon atoms of the substituent, and is usually 3 to 30, preferably 4 to 20. The number of carbon atoms of the "cycloalkenyl group" is not limited to the number of carbon atoms of the substituent, and is usually 3 to 30, preferably 4 to 20.

The alkenyl group and the cycloalkenyl group may have a substituent, and examples thereof include a vinyl group, a 1-propenyl group, a 2-butenyl group, a 3-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, a 5-hexenyl group, a 7-octenyl group, and a group having a substituent in these groups.

The "alkynyl group" may be any of a straight chain and a branched chain. The number of carbon atoms of the alkynyl group is not limited to the number of carbon atoms of the substituent, and is usually 2 to 20, preferably 3 to 20. The number of carbon atoms of the branched alkynyl group is not limited to the carbon atoms of the substituent, and is usually 4 to 30, preferably 4 to 20.

The number of carbon atoms of the "cycloalkynyl group" is not limited to the carbon atoms of the substituent, and is usually 4 to 30, preferably 4 to 20.

The alkynyl group and the cycloalkynyl group may have a substituent, and examples thereof include an ethynyl group, a 1-propynyl group, a 2-butynyl group, a 3-pentynyl group, a 4-pentynyl group, a 1-hexynyl group, a 5-hexynyl group, and groups having substituents of these groups.

The term "arylene group" refers to an atomic group obtained by removing 2 hydrogen atoms directly bonded to carbon atoms constituting a ring from an aromatic hydrocarbon. The number of carbon atoms of the arylene group is not limited to the number of carbon atoms of the substituent, and is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 18.

The arylene group may have a substituent, and examples of the arylene group include phenylene, naphthalenediyl, anthracenediyl, phenanthrenediyl, dihydrophenanthrenediyl, tetracenediyl, fluorenediyl, pyrenediyl, perylenediyl, perylene-diyl, and the like,The diradicals and the substituted groups of these groups are preferably those represented by the formulae (A-1) to (A-20). The arylene group includes a group in which a plurality of these groups are bonded.

[ wherein R and R^aEach independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group. Plural R and R being present^aEach of which may be the same or different, R^aMay be bonded to each other to form a ring together with the respective bonded atoms.]

The number of carbon atoms of the divalent heterocyclic group is not limited to the number of carbon atoms of the substituent, and is usually 2 to 60, preferably 3 to 20, and more preferably 4 to 15.

The divalent heterocyclic group may have a substituent, and examples of the divalent heterocyclic group include divalent groups obtained by removing 2 hydrogen atoms from a hydrogen atom directly bonded to a carbon atom or a heteroatom constituting the ring, preferably groups represented by formulae (AA-1) to (AA-34), such as pyridine, diazabenzene, triazine, azanaphthalene, naphthyridine, carbazole, dibenzofuran, dibenzothiophene, dibenzothiaole, phenoxazine, phenothiazine, acridine, dihydroacridine, furan, thiophene, oxazole, oxadiazole, and triazole. The divalent heterocyclic group includes a group in which a plurality of these groups are bonded.

[ wherein R and R^aThe same meaning as above is indicated.]

The "crosslinking group" is a group which can form a new bond by being subjected to heat treatment, ultraviolet irradiation treatment, near ultraviolet irradiation treatment, visible light irradiation treatment, infrared irradiation treatment, radical reaction, or the like, and is preferably a group represented by any of formulas (B-1) to (B-17). These groups may have a substituent.

"substituent" means a halogen atom, cyano group, alkyl group, cycloalkyl group, aryl group, monovalent heterocyclic group, alkoxy group, cycloalkoxy group, aryloxy group, amino group, substituted amino group, alkenyl group, cycloalkenyl group, alkynyl group, or cycloalkynyl group. The substituent may also be a crosslinking group.

Polymer Compound

In each ink composition, the solid component (a) preferably contains mutually different polymer compounds. In each ink composition, the light-emitting compound is exemplified as the polymer compound contained in the solid component (a). The light-emitting compound may be a compound which emits light by itself (light-emitting material), or may be a compound which causes the light-emitting material to emit light by transferring charge to the light-emitting material (host material). The polymer compound is preferably a light-emitting material. When the polymer compound is a light-emitting compound, it is preferably a polymer compound containing at least one structural unit selected from the structural units represented by the formula (X) and the structural units represented by the formula (Y) from the viewpoint of having excellent light-emitting characteristics.

In the composition of the present invention, the polymer compound containing at least one structural unit selected from the structural unit represented by the formula (X) and the structural unit represented by the formula (Y) may contain one kind of the single structural unit, or may contain two or more kinds of the structural units.

(structural unit represented by the formula (X))

[ in the formula,

a^X1and a^X2Each independently represents an integer of 0 or more.

Ar^X1And Ar^X3Each independently represents an arylene group or a divalent heterocyclic group, and these groups may have a substituent.

Ar^X2And Ar^X4Each independently represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, and these groups may have a substituent. In the presence of a plurality of Ar^X2And Ar^X4In the case of (3), they may be the same or different.

R^X1、R^X2And R^X3Each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. In the presence of a plurality of R^X2And R^X3In the case of (3), they may be the same or different.]

Since a light-emitting element having a film formed using the composition of the present invention has excellent light-emitting efficiency, a is preferable^X1Is an integer of 2 or less, more preferably 1.

Since a light-emitting element having a film formed using the composition of the present invention has excellent light-emitting efficiency, a is preferable^X2Is an integer of 2 or less, and more preferably 0.

R^X1、R^X2And R^X3Preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may have a substituent.

Ar^X1And Ar^X3The arylene group is more preferably a group represented by the formula (A-1) or the formula (A-9), and still more preferably a group represented by the formula (A-1), and these groups may have a substituent.

Ar^X1And Ar^X3The divalent heterocyclic group represented by the formula (AA-1), the formula (AA-2) or the formula (AA-7) to (AA-26) is more preferable, and these groups may have a substituent.

Ar^X1And Ar^X3Preferred is an arylene group which may have a substituent.

As Ar^X2And Ar^X4The arylene group is more preferably a group represented by the formula (A-1), the formula (A-6), the formula (A-7), the formula (A-9) to (A-11) or the formula (A-19), and these groups may have a substituent.

Ar^X2And Ar^X4More preferred ranges of the divalent heterocyclic groups shown and Ar^X1And Ar^X3More preferred ranges of the divalent heterocyclic groups shown are the same.

Ar^X2And Ar^X4More preferable ranges, still more preferable ranges, of the arylene group and the divalent heterocyclic group in the divalent group in which at least one of the arylene groups and at least one of the divalent heterocyclic groups are directly bonded to each other, and Ar^X1And Ar^X3More preferable ranges and further preferable ranges of the arylene group and the divalent heterocyclic group shown are the same.

As Ar^X2And Ar^X4Examples of the divalent group in which at least one of the arylene groups and at least one of the divalent heterocyclic groups are directly bonded to each other include groups represented by the following formulae, and these groups may have a substituent.

[ in the formula, R^XXRepresents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent.]

R^XXPreferably an alkyl group, a cycloalkyl group or an aryl group, and these groups may have a substituent.

Ar^X2And Ar^X4Preferred is an arylene group which may have a substituent.

As Ar^X1～Ar^X4And R^X1～R^X3Shown inThe group (b) may have a substituent, preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups may further have a substituent.

The structural units represented by the formula (X) are preferably structural units represented by the formulae (X-1) to (X-7), more preferably structural units represented by the formulae (X-1) to (X-6), and still more preferably structural units represented by the formulae (X-3) to (X-6).

[ in the formula, R^x4And R^x5Each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a halogen atom, a monovalent heterocyclic group, or a cyano group, and these groups may have a substituent. Plural R's present^x4May be the same or different. Plural R's present^x5May be the same or different, adjacent R^x5May be bonded to each other to form a ring together with the carbon atoms to which each is bonded.]

From the viewpoint of excellent hole-transporting properties of an organic EL element having a film formed using the composition of the present invention, the total amount of the structural units represented by the formula (X) relative to the total amount of the structural units contained in the polymer compound is preferably 0.1 to 50 mol%, more preferably 1 to 40 mol%, and still more preferably 5 to 30 mol%.

Examples of the structural unit represented by the formula (X) include structural units represented by the formulae (X1-1) to (X1-11), and structural units represented by the formulae (X1-3) to (X1-10) are preferable.

The structural unit represented by the formula (X) may include only one kind of the polymer compound, or may include two or more kinds of the polymer compound.

(structural Unit represented by the formula (Y))

[ wherein Ar is^Y1The term "divalent heterocyclic group" means an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, and these groups may have a substituent.]

Ar^Y1The arylene group is more preferably a group represented by the formula (A-1), the formula (A-2), the formula (A-6) - (A-10), the formula (A-19) or the formula (A-20), and still more preferably a group represented by the formula (A-1), the formula (A-2), the formula (A-7), the formula (A-9) or the formula (A-19), and these groups may have a substituent.

Ar^Y1The divalent heterocyclic group represented by the formula (AA-1) to (AA-4), the formula (AA-10) to (AA-15), the formula (AA-18) to (AA-21), the formula (AA-33) or the formula (AA-34) is more preferable, and the group represented by the formula (AA-4), the formula (AA-10), the formula (AA-12), the formula (AA-14) or the formula (AA-33) is further preferable, and these groups may have a substituent.

Ar^Y1More preferable ranges and still more preferable ranges of the arylene group and the divalent heterocyclic group in the divalent group in which at least one of the arylene groups and at least one of the divalent heterocyclic groups are directly bonded to each other are respectively the same as those of Ar mentioned above^Y1More preferable ranges and further preferable ranges of the arylene group and the divalent heterocyclic group shown are the same.

As Ar^Y1The divalent group in which at least one of the arylene groups and at least one of the divalent heterocyclic groups are directly bonded to Ar of the formula (X)^X2And Ar^X4The same divalent group as that formed by directly bonding at least one arylene group and at least one divalent heterocyclic group is shown.

Ar^Y1The substituent which the illustrated group may have is preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups may further have a substituent.

Examples of the structural units represented by the formula (Y) include structural units represented by the formulae (Y-1) to (Y-10), and structural units represented by the formulae (Y-1) to (Y-3) are preferable from the viewpoint of the luminance life of a light-emitting element having a film formed using the composition of the present invention, structural units represented by the formulae (Y-4) to (Y-7) are preferable from the viewpoint of the electron-transporting property of a light-emitting element having a film formed using the composition of the present invention, and structural units represented by the formulae (Y-8) to (Y-10) are preferable from the viewpoint of the light-emitting efficiency or the hole-transporting property of a light-emitting element having a film formed using the composition of the present invention.

[ in the formula, R^Y1Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. Plural R's present^Y1May be the same or different, adjacent R^Y1May be bonded to each other to form a ring together with the carbon atoms to which each is bonded.]

R^Y1Preferably a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and these groups may have a substituent.

The structural unit represented by the formula (Y-1) is preferably a structural unit represented by the formula (Y-1').

[ in the formula, R^Y11Represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. Plural R's present^Y11May be the same or different.]

R^Y11Preferably an alkyl group, a cycloalkyl group or an aryl group, more preferably an alkyl group or a cycloalkyl group, which may have a substituent.

[ in the formula,

R^Y1the same meaning as above is indicated.

X^Y1represents-C (R)^Y2)₂－、－C(R^Y2)＝C(R^Y2) -or-C (R)^Y2)₂－C(R^Y2)₂-a group as shown. R^Y2Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. Plural R's present^Y2May be the same or different, R^Y2May be bonded to each other to form a ring together with the carbon atoms to which each is bonded.]

R^Y2Preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, more preferably an alkyl group, a cycloalkyl group or an aryl group, which may have a substituent.

At X^Y1In, -C (R)^Y2)₂2R in the group shown^Y2The combination of (b) is preferably both alkyl groups or cycloalkyl groups, both aryl groups, both monovalent heterocyclic groups, or one of alkyl groups or cycloalkyl groups and the other of aryl groups or monovalent heterocyclic groups, more preferably one of alkyl groups or cycloalkyl groups and the other of aryl groups, which may have a substituent. 2R present^Y2May be bonded to each other to form a ring together with the atom to which each is bonded, in R^Y2When forming a ring, as-C (R)^Y2)₂The group represented by-is preferably a group represented by the formulae (Y-A1) to (Y-A5), more preferably a group represented by the formula (Y-A4), and these groups may have a substituent.

At X^Y1In, -C (R)^Y2)＝C(R^Y2) 2R in the group shown^Y2The combination of (b) is preferably both alkyl or cycloalkyl groups, or one is alkyl or cycloalkyl group and the other is aryl group, and these groups may have a substituent.

At X^Y1In, -C (R)^Y2)₂－C(R^Y2)₂4R in the group shown^Y2Preferred is an alkyl group or a cycloalkyl group which may have a substituent. Plural R's present^Y2May be bonded to each other to form a ring together with the atom to which each is bonded, in R^Y2When forming a ring, -C (R)^Y2)₂－C(R^Y2)₂The group represented by-is preferably a group represented by the formulae (Y-B1) to (Y-B5), more preferably a group represented by the formula (Y-B3), and these groups may have a substituent.

[ in the formula, R^Y2The same meaning as above is indicated.]

The structural unit represented by the formula (Y-2) is preferably a structural unit represented by the formula (Y-2').

[ in the formula, R^Y1And X^Y1The same meaning as above is indicated.]

[ in the formula, R^Y1And X^Y1The same meaning as above is indicated.]

The structural unit represented by the formula (Y-3) is preferably a structural unit represented by the formula (Y-3').

[ in the formula, R^Y11And X^Y1The same meaning as above is indicated.]

[ in the formula,

R^Y1the same meaning as above is indicated.

R^Y3Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent.]

R^Y3Preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may have a substituent.

The structural unit represented by the formula (Y-4) is preferably a structural unit represented by the formula (Y-4 '), and the structural unit represented by the formula (Y-6) is preferably a structural unit represented by the formula (Y-6').

[ in the formula, R^Y1And R^Y3The same meaning as above is indicated.]

[ in the formula,

R^Y1the same meaning as above is indicated.

R^Y4Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent.]

R^Y4Preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may have a substituent.

Examples of the structural unit represented by formula (Y) include structural units comprising an arylene group represented by formulae (Y-101) to (Y-121), structural units comprising a divalent heterocyclic group represented by formulae (Y-201) to (Y-206), and structural units comprising a divalent group in which at least one arylene group represented by formulae (Y-301) to (Y-304) and at least one divalent heterocyclic group are directly bonded.

For structural units of formula (Y) and Ar^Y1Since the organic EL element having a film formed using the composition of the present invention has an excellent luminance life, the total amount of the constitutional units contained in the polymer compound is preferably 0.5 to 90 mol%, and more preferably 30 to 80 mol%.

For a structural unit represented by formula (Y) and Ar^Y1Since the organic EL element having a film formed using the composition of the present invention has excellent light emission efficiency, hole transporting property, or electron transporting property, the structural unit that is a divalent group in which a divalent heterocyclic group or at least one arylene group is directly bonded to at least one divalent heterocyclic group is preferably 0.5 to 50 mol%, more preferably 3 to 30 mol%, based on the total amount of the structural units contained in the polymer compound.

The structural unit represented by the formula (Y) may include only one kind of the polymer compound, or may include two or more kinds of the polymer compound.

Examples of the polymer compound include polymer compounds (P-101) to (P-107) shown in Table 1.

[ TABLE 1]

In the table, p, q, r, s and t represent the molar ratio of each structural unit. p + q + r + s + t is 100 and 100. gtoreq + q + r + s. gtoreq 70. The other structural units are structural units other than the structural unit represented by formula (Y) and the structural unit represented by formula (X). ]

When a polymer compound containing at least one structural unit selected from the structural unit represented by the formula (X) and the structural unit represented by the formula (Y) is used alone as a light-emitting material (that is, when another light-emitting material such as an iridium complex described later is not used),

as the polymer compound, there is used,

preferably a polymer compound comprising at least one structural unit selected from the group consisting of a structural unit represented by the formula (Y-8), a structural unit represented by the formula (Y-9) and a structural unit represented by the formula (Y-10),

more preferably a polymer compound containing at least one structural unit selected from the structural unit represented by the formula (Y-8) and the structural unit represented by the formula (Y-9),

more preferably a polymer compound containing a structural unit represented by the formula (Y-8).

Further, the polymer compound is preferably a polymer compound containing at least one structural unit selected from the group consisting of the structural unit represented by the formula (Y-1), the structural unit represented by the formula (Y-2), the structural unit represented by the formula (Y-3) and the structural unit represented by the formula (X) as a structural unit other than the structural unit represented by the formula (Y-8), the structural unit represented by the formula (Y-9) and the structural unit represented by the formula (Y-10),

more preferably a polymer compound containing at least one structural unit selected from the group consisting of the structural unit represented by the formula (Y-1), the structural unit represented by the formula (Y-2) and the structural unit represented by the formula (X) as a structural unit other than the structural unit represented by the formula (Y-8), the structural unit represented by the formula (Y-9) and the structural unit represented by the formula (Y-10),

more preferably a polymer compound containing at least one structural unit selected from the group consisting of the structural unit represented by the formula (Y-2) and the structural unit represented by the formula (X) as a structural unit other than the structural unit represented by the formula (Y-8), the structural unit represented by the formula (Y-9) and the structural unit represented by the formula (Y-10),

particularly preferred is a polymer compound containing a structural unit represented by the formula (Y-2) and a structural unit represented by the formula (X) as structural units other than the structural unit represented by the formula (Y-8), the structural unit represented by the formula (Y-9) and the structural unit represented by the formula (Y-10).

Process for producing Polymer Compound

The polymer compound containing at least one structural unit selected from the structural unit represented by the formula (X) and the structural unit represented by the formula (Y) can be produced by a known polymerization method described in chem.rev.) 109, 897-1091 (2009) and the like, and examples thereof include a method of polymerizing by a coupling reaction using a transition metal catalyst, such as Suzuki reaction, Yamamoto reaction, Buchwald reaction, Stille reaction, Negishi reaction, and Kumada reaction.

In the above polymerization method, examples of the method of charging the monomer include: a method of putting the total amount of the monomers into the reaction system at one time; a method in which after a part of the monomers is charged and reacted, the remaining monomers are charged at once, continuously or in batches; a method of charging the monomers continuously or in portions; and so on.

Examples of the transition metal catalyst include a palladium catalyst and a nickel catalyst.

The post-treatment of the polymerization reaction is carried out by a known method alone or in combination, for example: a method of removing water-soluble impurities by liquid separation; a method of adding the reaction solution after the polymerization reaction to a lower alcohol such as methanol, filtering the precipitated precipitate, and drying the precipitate; and so on. When the purity of the polymer compound is low, the polymer compound can be purified by a usual method such as recrystallization, reprecipitation, continuous extraction with a soxhlet extractor, column chromatography, or the like.

Iridium complex

Since the organic EL element having a film formed using the composition of the present invention has more excellent light emission efficiency, the iridium complex is preferably an iridium complex represented by formula (Ir-1), an iridium complex represented by formula (Ir-2), an iridium complex represented by formula (Ir-3), an iridium complex represented by formula (Ir-4), or an iridium complex represented by formula (Ir-5), and more preferably an iridium complex represented by formula (Ir-1), an iridium complex represented by formula (Ir-2), or an iridium complex represented by formula (Ir-3).

[ in the formula,

n^D1represents 1, 2 or 3. n is^D2 Represents 1 or 2.

R^D1、R^D2、R^D3、R^D4、R^D5、R^D6、R^D7、R^D8、R^D11、R^D12、R^D13、R^D14、R^D15、R^D16、R^D17、R^D18、R^D19、R^D20、R^D21、R^D22、R^D23、R^D24、R^D25、R^D26、R^D31、R^D32、R^D33、R^D34、R^D35、R^D36And R^D37Each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, or a halogen atom, and these groups may have a substituent. R^D1、R^D2、R^D3、R^D4、R^D5、R^D6、R^D7、R^D8、R^D11、R^D12、R^D13、R^D14、R^D15、R^D16、R^D17、R^D18、R^D19、R^D20、R^D21、R^D22、R^D23、R^D24、R^D25、R^D26、R^D31、R^D32、R^D33、R^D34、R^D35、R^D36And R^D37When a plurality of the compounds exist, they may be the same or different.

－A^D1---A^D2-represents an anionic bidentate ligand. A. the^D1And A^D2Each independently represents a carbon atom, an oxygen atom or a nitrogen atom bonded to the iridium atom, and these atoms may be atoms constituting a ring. In the presence of a plurality of-A^D1---A^D2In the case of (A) and (B), they may be the same or different.]

In the iridium complex represented by the formula (Ir-1), R^D1～R^D8At least 1 ofA group represented by the formula (D-A) is preferred.

In the iridium complex represented by the formula (Ir-2), R is preferably^D11～R^D20At least 1 of them is a group represented by the formula (D-A).

In the iridium complex represented by the formula (Ir-3), R is preferably^D1～R^D8And R^D11～R^D20At least 1 of them is a group represented by the formula (D-A).

In the iridium complex represented by the formula (Ir-4), R is preferably^D21～R^D26At least 1 of them is a group represented by the formula (D-A).

In the iridium complex represented by the formula (Ir-5), R is preferably^D31～R^D37At least 1 of them is a group represented by the formula (D-A).

[ in the formula,

m^DA1、m^DA2and m^DA3Each independently represents an integer of 0 or more.

G^DARepresents a nitrogen atom, an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent.

Ar^DA1、Ar^DA2And Ar^DA3Each independently represents an arylene group or a divalent heterocyclic group, and these groups may have a substituent. Ar (Ar)^DA1、Ar^DA2And Ar^DA3When a plurality of the compounds exist, they may be the same or different.

T^DARepresents an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. Multiple T of existence^DAMay be the same or different.]

m^DA1、m^DA2And m^DA3Usually, it is an integer of 10 or less, preferably an integer of 5 or less, and more preferably 0 or 1. m is^DA1、m^DA2And m^DA3Preferably the same integer.

G^DAPreferably represented by the formulae (GDA-11) to (GDA-15)These groups may have a substituent.

[ in the formula,

each of which represents Ar^DA1、Ar^DA2、Ar^DA3Bonding of (2).

R^DARepresents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may further have a substituent. In the presence of a plurality of R^DAThey may be the same or different.]

R^DAPreferably a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a cycloalkoxy group, more preferably a hydrogen atom, an alkyl group or a cycloalkyl group, which may have a substituent.

Ar^DA1、Ar^DA2And Ar^DA3Preferred are groups represented by the formulae (ArDA-1) to (ArDA-3).

[ in the formula,

R^DAthe same meaning as above is indicated.

R^DBRepresents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. In the presence of a plurality of R^DBIn the case of (2), they may be the same or different.]

T^DAPreferred are groups represented by the formulae (TDA-1) to (TDA-3).

[ in the formula, R^DAAnd R^DBThe same meaning as above is indicated.]

The group represented by the formula (D-A) is preferably a group represented by the formulae (D-A1) to (D-A3).

[ in the formula,

np1 represents an integer of 0 to 5, np2 represents an integer of 0 to 3, and np3 represents 0 or 1. The plurality of nps 1 present may be the same or different.

R^p1、R^p2And R^p3Each independently represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group or a halogen atom. R^p1And R^p2When a plurality of the compounds exist, they may be the same or different.]

np1 is preferably 0 or 1, more preferably 1. np2 is preferably 0 or 1, more preferably 0. np3 is preferably 0.

R^p1、R^p2And R^p3Preferably an alkyl or cycloalkyl group.

As a^D1---A^D2Examples of the anionic bidentate ligand represented by the above formula include ligands represented by the following formulae.

[ in the formula, a represents a site bonded to an iridium atom. ]

The iridium complex represented by formula (Ir-1) is preferably an iridium complex represented by formulae (Ir-11) to (Ir-13). The iridium complex represented by the formula (Ir-2) is preferably an iridium complex represented by the formula (Ir-21). The iridium complex represented by formula (Ir-3) is preferably an iridium complex represented by formulae (Ir-31) to (Ir-33). The iridium complex represented by formula (Ir-4) is preferably an iridium complex represented by formulae (Ir-41) to (Ir-43). The iridium complex represented by formula (Ir-5) is preferably an iridium complex represented by formulae (Ir-51) to (Ir-53).

[ in the formula,

n^D2represents 1 or 2.

D represents a group represented by the formula (D-A). The plurality of D's present may be the same or different.

R^DCRepresents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. Plural R's present^DCMay be the same or different.

R^DDRepresents an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. Plural R's present^DDMay be the same or different.]

Examples of the iridium complex include iridium complexes represented by the following formulae.

The iridium complex can be synthesized, for example, by the methods described in Japanese patent application laid-open Nos. 2004-530254, 2008-179617, 2011-105701, 2007-504272, 2013-147449, and 2013-147450.

The solid component (a) may contain a polymer compound containing an iridium complex structural unit. The structural unit of the iridium complex is a structural unit having a structure of an iridium complex represented by formula (Ir-1), formula (Ir-2), formula (Ir-3), formula (Ir-4) or formula (Ir-5). The structural unit having the structure of the iridium complex represented by formula (Ir-1), formula (Ir-2), formula (Ir-3), formula (Ir-4) or formula (Ir-5) is preferably a structural unit having a group obtained by removing 1 or more and 3 or less hydrogen atoms directly bonded to a carbon atom or a heteroatom constituting the iridium complex from the iridium complex represented by formula (Ir-1), formula (Ir-2), formula (Ir-3), formula (Ir-4) or formula (Ir-5), and more preferably a structural unit having a group obtained by removing 2 hydrogen atoms directly bonded to a carbon atom or a heteroatom constituting the iridium complex from the iridium complex represented by formula (Ir-1), formula (Ir-2), formula (Ir-3), formula (Ir-4) or formula (Ir-5).

The polymer compound containing an iridium complex structural unit is preferably a polymer compound further containing at least one structural unit selected from the structural units represented by the formula (X) and the structural units represented by the formula (Y).

Among these, as the polymer compound containing an iridium complex structural unit,

preferably a polymer compound comprising at least one structural unit selected from the group consisting of a structural unit represented by the formula (Y-4), a structural unit represented by the formula (Y-5), a structural unit represented by the formula (Y-6) and a structural unit represented by the formula (Y-7),

more preferably a polymer compound containing at least one structural unit selected from the structural unit represented by the formula (Y-4) and the structural unit represented by the formula (Y-6),

more preferably a polymer compound containing a structural unit represented by the formula (Y-4).

Further, the polymer compound containing an iridium complex structural unit is preferably a polymer compound containing at least one structural unit selected from the group consisting of a structural unit represented by the formula (Y-1), a structural unit represented by the formula (Y-2), a structural unit represented by the formula (Y-3) and a structural unit represented by the formula (X) as a structural unit other than the structural unit represented by the formula (Y-4), the structural unit represented by the formula (Y-5), the structural unit represented by the formula (Y-6) and the structural unit represented by the formula (Y-7),

more preferably a polymer compound containing at least one structural unit selected from the group consisting of the structural unit represented by the formula (Y-1), the structural unit represented by the formula (Y-2) and the structural unit represented by the formula (X) as a structural unit other than the structural unit represented by the formula (Y-4), the structural unit represented by the formula (Y-5), the structural unit represented by the formula (Y-6) and the structural unit represented by the formula (Y-7).

The iridium complex structural unit may include only one kind of the polymer compound, or may include two or more kinds of the polymer compound.

Main Material

In each ink composition, when the solid component (a) contains a light-emitting material, particularly when an iridium complex is contained as a light-emitting material, the light-emitting efficiency of an organic EL element having a film formed using the composition of the present invention is further improved by using the composition in combination with a host material having at least one function selected from the group consisting of a hole-transporting property, a hole-injecting property, an electron-transporting property, and an electron-injecting property. That is, in the composition of the present invention, when the iridium complex is contained as a light-emitting material, it is preferable that the composition further contains a host material. When the host material is contained in the composition of the present invention, the host material may be contained alone or in two or more kinds.

When each ink composition contains an iridium complex and a host material, the content of the iridium complex is usually 0.05 to 80 parts by mass, preferably 0.1 to 60 parts by mass, and more preferably 0.5 to 50 parts by mass, based on 100 parts by mass of the total content of the iridium complex and the host material.

From the viewpoint of excellent light emission efficiency of an organic EL element having a film formed using the composition of the present invention, the lowest excited triplet state (T1) of the host material is preferably an energy level equal to or higher than T1 of the iridium complex.

The host material is classified into a low-molecular compound (hereinafter also referred to as a "low-molecular host") and a high-molecular compound (hereinafter also referred to as a "high-molecular host"), and may be either a low-molecular host or a high-molecular host, and is preferably a high-molecular host.

Examples of the low-molecular host include: a compound having a carbazole structure, a compound having a triarylamine structure, a compound having a phenanthroline structure, a compound having a triaryltriazine structure, a compound having an azole structure, a compound having a benzothiophene structure, a compound having a benzofuran structure, a compound having a fluorene structure, a compound having a spirofluorene structure, and the like.

Specific examples of the low molecular host include compounds represented by the following formulae.

The polymer main body is preferably the above-mentioned polymer compound containing at least one structural unit selected from the structural unit represented by the formula (X) and the structural unit represented by the formula (Y).

Among these, as a main polymer body,

preferably a polymer compound comprising at least one structural unit selected from the group consisting of a structural unit represented by the formula (Y-4), a structural unit represented by the formula (Y-5), a structural unit represented by the formula (Y-6) and a structural unit represented by the formula (Y-7),

more preferably a polymer compound containing at least one structural unit selected from the structural unit represented by the formula (Y-4) and the structural unit represented by the formula (Y-6),

more preferably a polymer compound containing a structural unit represented by the formula (Y-4).

Further, the polymer main body is preferably a polymer compound containing at least one structural unit selected from the group consisting of the structural unit represented by the formula (Y-1), the structural unit represented by the formula (Y-2), the structural unit represented by the formula (Y-3) and the structural unit represented by the formula (X) as a structural unit other than the structural unit represented by the formula (Y-4), the structural unit represented by the formula (Y-5), the structural unit represented by the formula (Y-6) and the structural unit represented by the formula (Y-7),

more preferably a polymer compound containing at least one structural unit selected from the group consisting of the structural unit represented by the formula (Y-1), the structural unit represented by the formula (Y-2) and the structural unit represented by the formula (X) as a structural unit other than the structural unit represented by the formula (Y-4), the structural unit represented by the formula (Y-5), the structural unit represented by the formula (Y-6) and the structural unit represented by the formula (Y-7).

Low molecular weight Compound

In each ink composition, the low-molecular compound contained in the solid component (a) is not particularly limited, and examples thereof include the light-emitting material such as the iridium complex described above, the host material described above, the hole-transporting material described below, the hole-injecting material, the electron-transporting material, the electron-injecting material, and an antioxidant.

Other solid ingredients

The solid component (a) contained in each ink composition may include a hole transport material, a hole injection material, an electron transport material, an electron injection material, and a light-emitting compound described below.

(hole transport material)

The hole transport material is classified into a low molecular compound and a high molecular compound, preferably a high molecular compound, and more preferably a high molecular compound having a crosslinking group.

Examples of the polymer compound include polyvinylcarbazole and derivatives thereof; polyarylene having an aromatic amine structure in a side chain or a main chain, and a derivative thereof. The polymer compound may be a compound to which an electron accepting moiety is bonded. Examples of the electron accepting site include fullerene, tetrafluorotetracyanoquinodimethane (テ ト ラ フ ル オ ロ テ ト ラ シ ア ノ キ ノ ジ メ タ ン), tetracyanoethylene, trinitrofluorenone, and the like, and fullerene is preferable.

In the composition of the present invention, the hole transport material may contain one kind alone, or two or more kinds thereof.

(Electron transport Material)

The electron transport materials are classified into low molecular compounds and high molecular compounds. The electron transport material may have a crosslinking group.

Examples of the low-molecular compound include metal complexes having 8-hydroxyquinoline as a ligand, oxadiazoles, anthraquinone dimethanes, benzoquinones, naphthoquinones, anthraquinones, tetracyanoanthraquinone dimethanes, fluorenones, diphenyldicyanoethylenes, diphenoquinones, and derivatives thereof.

Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.

In the ink composition, the electron transporting material may be contained alone, or may be contained in two or more kinds.

(hole injecting Material and Electron injecting Material)

The hole injection material and the electron injection material are each classified into a low molecular compound and a high molecular compound. The hole injection material and the electron injection material may have a crosslinking group.

Examples of the low-molecular-weight compound include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides of molybdenum, tungsten, and the like; metal fluorides such as lithium fluoride, sodium fluoride, cesium fluoride and potassium fluoride.

Examples of the polymer compound include polyaniline, polythiophene, polypyrrole, polyphenylene vinylene, polythiophene vinylene (ポ リ チ エ ニ レ ン ビ ニ レ ン), polyquinoline, polyquinoxaline, and derivatives thereof; and a conductive polymer such as a polymer having an aromatic amine structure in a main chain or a side chain.

In each ink composition, the hole injection material and the electron injection material may be contained singly or in two or more kinds.

When the hole injection material or the electron injection material contains a conductive polymer, the conductivity of the conductive polymer is preferably 1 × 10^－5S/cm～1×10³S/cm. In order to set the conductivity of the conductive polymer within this range, an appropriate amount of ions may be doped into the conductive polymer.

The kind of the doped ion is an anion in the case of a hole injection material, and a cation in the case of an electron injection material. Examples of the anion include a polystyrene sulfonate ion, an alkylbenzene sulfonate ion, and a camphor sulfonate ion. Examples of the cation include lithium ion, sodium ion, potassium ion, and tetrabutylammonium ion.

The doping ions may be used alone or in combination of two or more.

(luminescent Compound)

In each ink composition, the solid component (a) may contain a light-emitting compound other than the above-described polymer compound or low-molecular compound (hereinafter also referred to as "other light-emitting compound") exemplified as the light-emitting compound. Examples of the other light-emitting compound include naphthalene and a derivative thereof, anthracene and a derivative thereof, and perylene and a derivative thereof.

In each ink composition, the other light-emitting compound may be contained alone, or may be contained in two or more kinds.

(antioxidant)

Each ink composition may contain an antioxidant that is soluble in the solvent (B) and does not impair light emission and charge transport. Examples of the antioxidant include a phenol-based antioxidant and a phosphorus-based antioxidant.

In each ink composition, the antioxidant may be contained alone, or may be contained in two or more kinds.

< composition ratio >

Each ink composition contains a solid component (a) and a solvent (B). In each ink composition, the content of the solid component (a) is usually 0.1 to 10.0 parts by mass when the content of the solvent (B) is 100 parts by mass, and is preferably 0.2 to 7.0 parts by mass, and more preferably 0.3 to 5.0 parts by mass because of excellent ejection performance in the inkjet printing method.

< viscosity >

From the viewpoint of coatability, the viscosity of each ink composition at a temperature of 23 ℃ is preferably 1cP or more and 10cP or less, and more preferably 2cP or more and 8cP or less.

[ method for producing ink composition ]

Each ink composition can be prepared by mixing the solid component (a), the solvent (B), and other components, for example. The order of mixing the components is not limited, and the target ink composition may be prepared by mixing a part or all of the solid component (a) with a part of the solvent (B) in advance, and then mixing the remaining components so as to obtain a predetermined concentration.

[ film ]

The first film and the second film are films formed using the first ink composition and the second ink composition, respectively. In each film, the solid content contained in each ink composition may be contained as it is, or may be contained in a state in which the solid content is crosslinked intramolecularly or intermolecularly or intramolecularly and intermolecularly (crosslinked material). The film containing a crosslinked solid content is a film obtained by crosslinking a coating layer containing a solid content by external stimulation such as heating or light irradiation. The film containing a crosslinked solid content is substantially insoluble in a solvent, and therefore can be suitably used for lamination.

The heating temperature for crosslinking the solid component is usually 25 to 300 ℃, preferably 50 to 250 ℃, and more preferably 150 to 200 ℃.

The kind of light used for light irradiation for crosslinking the solid component is, for example, ultraviolet light, near ultraviolet light, visible light, or infrared light.

Each film is suitable as a light-emitting layer, a hole-transporting layer, or a hole-injecting layer in a light-emitting element. The thickness of each film is usually 1nm to 1 μm. The flatness R of the film is preferably 60% or more, more preferably 70% or more, and further preferably 90% or more. The flatness R of the film in this specification is a value calculated by a calculation method described later.

< use >)

The film obtained by the production method according to the present invention is useful as an element of an organic EL device, an element of a color filter, or the like. The organic EL element includes two or more types of pixels provided on a substrate, and generally has a pair of electrodes including an anode and a cathode corresponding to each pixel. The two or more kinds of pixels include at least a first pixel and a second pixel. The first pixel has a first film formed using a first ink composition. The second pixel has a second film formed using a second ink composition. The two or more kinds of pixels are not limited to two kinds, and for example, three kinds of pixels R, G, B may be used. The organic EL element can be used for a display of a computer, a television, a portable terminal, or the like. The organic EL element can also be used as a planar light source for a backlight of a liquid crystal display device or a planar illumination light source. The flexible substrate can be used as a curved light source or a display device.

[ method for producing organic EL element ]

The method for manufacturing an organic EL element according to the present invention includes a step of manufacturing a film by the above-described method for manufacturing a film.

< organic EL element >

Layer composition

The first film formed using the first ink composition and the second film formed using the second ink composition are usually at least one layer selected from a light-emitting layer, a hole-transporting layer, a hole-injecting layer, an electron-transporting layer, and an electron-injecting layer, and are preferably light-emitting layers. These layers respectively contain a light-emitting compound, a hole-transporting material, a hole-injecting material, an electron-transporting material, and an electron-injecting material.

The organic EL element has a light-emitting layer between an anode and a cathode. The organic EL element preferably has at least 1 of the hole injection layer and the hole transport layer between the anode and the light-emitting layer from the viewpoint of hole injection property and hole transport property, and preferably has at least 1 of the electron injection layer and the electron transport layer between the cathode and the light-emitting layer from the viewpoint of electron injection property and electron transport property.

In the case where the material for the hole transport layer, the material for the electron transport layer, and the material for the light-emitting layer are each dissolved in a solvent used in the formation of a layer adjacent to the hole transport layer, the electron transport layer, and the light-emitting layer in the production of the organic EL element, it is preferable that the materials have a crosslinking group in order to avoid the dissolution of the materials in the solvent. After each layer is formed using a material having a crosslinking group, the crosslinking group is crosslinked, whereby the layer can be rendered substantially insoluble in a solvent.

In the organic EL element, when a low molecular compound is used as a method for forming each layer such as a light-emitting layer, a hole transport layer, an electron transport layer, a hole injection layer, and an electron injection layer, examples of the method include: examples of the method using a polymer compound include a method using a vacuum vapor deposition method using a powder and a method using a film formed from a solution or a molten state. The method for manufacturing an organic EL element according to the present invention includes at least: the coating method includes a first coating step of forming a first coating layer, a second coating step of forming a second coating layer, and a drying step of drying the first coating layer and the second coating layer to form a first film and a second film.

The order, number, and thickness of the stacked layers are adjusted in consideration of light emission efficiency and luminance lifetime.

Electrodes

Examples of the material of the anode include conductive metal oxides and translucent metals, and indium oxide, zinc oxide, and tin oxide are preferable; conductive compounds such as Indium Tin Oxide (ITO) and indium zinc oxide; silver and palladium and copper complexes (APC); NESA, gold, platinum, silver, copper.

Examples of the material of the cathode include metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc, and indium; alloys of two or more of them; alloys of one or more of them with one or more of silver, copper, manganese, titanium, cobalt, nickel, tungsten, and tin; and graphite intercalation compounds. Examples of the alloy include a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy. The anode and the cathode may each have a 2-layer or more stacked structure.

[ ink composition set ]

The ink composition set according to the present invention is an ink composition set for producing a film, which includes at least the first ink composition and the second ink composition. By producing a film including two or more types of films using the ink composition set according to the present invention, even when two or more types of films are formed, two or more types of films having excellent flatness can be produced without resorting to a complicated drying process. The ink composition set according to the present invention is useful for the production of organic EL devices.