KR102490725B1 - Composition for forming organic electroluminescent device, method for manufacturing organic electroluminescent device and organic film - Google Patents

Abstract

A composition for forming an organic electroluminescent element capable of improving the uniformity of film thickness of an organic film in a region surrounded by banks in a case where an organic film constituting an organic electroluminescent element is formed by wet film formation. The composition for forming an organic electroluminescent device of the present invention contains a charge injection and transport material, an organic solvent, and at least two types of surface modifiers.

Description

Composition for forming organic electroluminescent device, method for manufacturing organic electroluminescent device and organic film

The present invention relates to a method for producing a composition for forming an organic electroluminescent device, an organic electroluminescent device, and an organic film.

The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2016-240539 filed with the Japan Patent Office on December 12, 2016, and some or all of the contents disclosed in the documents cited in this specification are cited here And, it is introduced as the disclosure content of this specification.

As a method for manufacturing an organic electroluminescent device, a manufacturing method in which organic materials are formed into a film by a vacuum deposition method and then laminated is common. However, in recent years, as a manufacturing method with more excellent material use efficiency, a film is formed by an inkjet method or the like of a solution of an organic material. Research on a manufacturing method by wet film formation in which film is deposited and laminated is being actively pursued.

In the manufacture of an organic electroluminescent element, particularly an organic EL display, by wet film formation, each pixel is partitioned with a partition called a bank, and an organic film constituting the organic electroluminescent element is formed in a minute region within the bank. It has been studied to use a method of discharging a coating liquid, which is a composition for forming a light emitting element, by an inkjet method to form a film. At this time, a technique for obtaining a flatter film in a region surrounded by banks by mixing various surface modifiers with a coating liquid has been proposed (Patent Documents 1 and 2).

In Patent Literature 1, it is described that a specific high molecular compound is contained in the composition for forming a light emitting layer in order to form a uniform film. An example of the specific high molecular compound is polysiloxane, and it is disclosed that a uniform film is formed by forming a film in a bank by an inkjet method.

In Patent Literature 2, it is disclosed that a flat film can be obtained in a region surrounded by barrier ribs by incorporating a specific amount of a leveling agent, particularly a leveling agent containing a silicon-based compound or a fluorine-based compound, into a coating liquid for forming a light emitting layer.

However, it was difficult to say that sufficient flatness was still obtained by these methods.

International Publication No. 2010/104183 Japanese Unexamined Patent Publication No. 2002-056980

The present invention provides a composition for forming an organic electroluminescent element capable of improving the uniformity of the film thickness in a region surrounded by banks of the organic film in the case where an organic film constituting the organic electroluminescent element is formed by wet film formation. aims to

As a result of intensive studies, the present inventors have found that, in the case where the organic film constituting the organic electroluminescent element is formed by wet film formation, an organic electroluminescent element containing two types of surface modifiers having different surface tensions when dissolved in the same solvent The inventors have found that an organic film having excellent uniformity can be realized by using the forming composition, and completed the present invention.

That is, this invention has the following structures.

[1] A composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, at least one first surface modifier and at least one second surface modifier,

The surface tension (unit: mN/m) of the organic solvent is Sa, the total content of the one or more first surface modifiers with respect to 100 parts by weight of the organic solvent is C1 parts by weight, and 100 parts by weight of the organic solvent The content of the total of the one or more types of second surface modifiers for C2 parts by weight,

Each of the first surface modifiers satisfies the following formula (1) when S1y is the surface tension (unit: mN/m) of a mixture in which 0.01 part by weight of the first surface modifier is dissolved in 100 parts by weight of the organic solvent. It is a surface modifier to

Sa-S1y>1.0 … (One)

Each of the second surface modifiers satisfies the following formula (2) when the surface tension (unit: mN/m) of a mixture in which 0.01 part by weight of the second surface modifier is dissolved in 100 parts by weight of the organic solvent is S2y. It is a surface modifier to

Sa-S2y≤1.0 … (2)

When the surface tension (unit: mN/m) of a mixture of 100 parts by weight of the organic solvent and the C1 part by weight of the first surface modifier is S1x, the following formula (3) is satisfied,

Sa-S1x>1.0 … (3)

When S2x is the surface tension (unit: mN/m) of a mixture of 100 parts by weight of the organic solvent and the C2 part by weight of the second surface modifier, the following formula (4) is satisfied,

Sa-S2x<1.0 … (4)

A composition for forming an organic electroluminescent device.

[2] The composition for forming an organic electroluminescent element according to [1], wherein C1 is 0.001 to 1.

[3] The composition for forming an organic electroluminescent element according to [1] or [2], wherein C2 is 0.001 to 1.

[4] The composition for forming an organic electroluminescent element according to any one of [1] to [3], wherein the first surface modifier is a material containing silicon and/or fluorine.

[5] The composition for forming an organic electroluminescent device according to any one of [1] to [4], wherein the second surface modifier is a surfactant.

[6] The composition for forming an organic electroluminescent device according to [5], wherein the surfactant is a nonionic surfactant selected from the group consisting of ether type, ester type, and ether ester type.

[7] A composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a fifth surface modifier and a sixth surface modifier,

The surface tension of pure water (unit: mN/m) is Sa', and the surface tension of a mixture of 100 parts by weight of pure water and 0.1 part by weight of the fifth surface modifier (unit: mN/m) is S1z, When S2z is the surface tension (unit: mN/m) of a mixture of 100 parts by weight of pure water and 0.1 part by weight of the sixth surface modifier, the following equation (5) is satisfied,

Sa'>S1z>S2z . . . (5)

A composition for forming an organic electroluminescent device.

[8] The composition for forming an organic electroluminescent device according to [7], wherein the content of the fifth surface modifier is 0.001 to 1 part by weight based on 100 parts by weight of the organic solvent.

[9] The composition for forming an organic electroluminescent device according to [7] or [8], wherein the content of the sixth surface modifier is 0.001 to 1 part by weight based on 100 parts by weight of the organic solvent.

[10] The composition for forming an organic electroluminescent device according to any one of [7] to [9], wherein the fifth surface modifier is a material containing silicon and/or fluorine.

[11] The composition for forming an organic electroluminescent device according to any one of [7] to [10], wherein the sixth surface modifier is a surfactant.

[12] The composition for forming an organic electroluminescent device according to [11], wherein the surfactant is a nonionic surfactant selected from the group consisting of ether type, ester type, and ether/ester type.

[13] An organic electroluminescent device comprising an organic film formed by drying the composition for forming an organic electroluminescent device according to any one of [1] to [12].

[14] Including application of the composition for forming an organic electroluminescent element according to any one of [1] to [12] to a region partitioned by a barrier rib, and drying the applied composition for forming an organic electroluminescent element, A method for producing an organic film.

According to the composition for forming an organic electroluminescent element according to the present invention, the uniformity of the film thickness of the organic film in the region surrounded by the bank can be improved, and the characteristics of the organic electroluminescent element can be improved.

1 is a schematic cross-sectional view showing an example of an embodiment of an organic electroluminescent device of the present invention.
Fig. 2 is a schematic view showing the state of formation of an organic film into a partition wall in Example.

Hereinafter, preferred embodiments of the composition for forming an organic electroluminescent device of the present invention will be described in detail. In addition, in description of drawings, the same code|symbol is attached|subjected to the same element, and redundant description is abbreviate|omitted. Also, for convenience of illustration, the dimensional ratios in the drawings do not necessarily correspond to those described. In addition, this invention is not limited to the content demonstrated below, It is possible to implement with arbitrary change in the range which does not change the summary.

In addition, unless otherwise indicated, the content and concentration in the present invention represent the content and concentration when the amount of the organic solvent contained in the composition for forming an organic electroluminescent element is taken as a reference value. For example, in the case of a substance having a content of 100 ppm by weight, it means that 0.01 part by weight of the substance is contained with respect to 100 parts by weight of the organic solvent.

In addition, unless otherwise indicated, in this specification, a numerical range expressed using "to" means a range including the numerical values described before and after "to" as a lower limit and an upper limit, and "A to B" It means more than A and less than B.

[Composition for Forming Organic Electroluminescent Device]

The composition for forming an organic electroluminescent device of the present invention contains a charge injection and transport material, an organic solvent, and at least two types of surface modifiers.

A first aspect of the composition for forming an organic electroluminescent device of the present invention is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a first surface modifier and a second surface modifier,

If the surface tension of the organic solvent alone is Sa (mN / m),

The first surface modifier has a surface tension (S1y) of Sa-S1y > 1.0 when 100 ppm by weight of the first surface modifier is dissolved in the organic solvent (hereinafter referred to as "formula (1)" in some cases). ) indicates that

The second surface modifier has a surface tension (S2y) of Sa-S2y ≤ 1.0 when 100 ppm by weight of the second surface modifier is dissolved in the organic solvent (hereinafter referred to as "Formula (2)" in some cases. ) indicates that

The surface tension when only all the first surface modifiers are dissolved in the organic solvent at the same concentration (% by weight) as the concentration in the composition for forming an organic electroluminescent device is S1x (mN/m);

When only all the second surface modifiers are dissolved in the organic solvent at the same concentration (% by weight) as the concentration in the composition for forming an organic electroluminescent element, the surface tension is S2x (mN / m),

Sa-S1x > 1.0 (hereinafter sometimes referred to as "Equation (3)"), and Sa-S2x < 1.0 (hereinafter sometimes referred to as "Equation (4)")

It is characterized in that it satisfies.

That is, the first aspect of the composition for forming an organic electroluminescent device of the present invention is to form an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, at least one first surface modifier and at least one second surface modifier. As a composition for

The surface tension (unit: mN/m) of the organic solvent is taken as Sa, and the content of the first surface modifier relative to 100 parts by weight of the organic solvent (when two or more types of first surface modifiers are used, the total content thereof) is C1 parts by weight, and the content of the second surface modifier relative to 100 parts by weight of the organic solvent (when two or more types of second surface modifiers are used, the total content thereof) is C2 parts by weight,

Each first surface modifier is a surface modifier that satisfies the following formula (1) when the surface tension (unit: mN/m) of a mixture in which 0.01 part by weight of the first surface modifier is dissolved in 100 parts by weight of an organic solvent is S1y. ego,

Sa-S1y>1.0 … (One)

Each second surface modifier is a surface modifier that satisfies the following formula (2) when the surface tension (unit: mN/m) of a mixture in which 0.01 part by weight of the second surface modifier is dissolved in 100 parts by weight of an organic solvent is S2y. ego,

Sa-S2y≤1.0 … (2)

A mixture of 100 parts by weight of the organic solvent and C1 parts by weight of the first surface modifier (that is, in the organic solvent, only all the first surface modifiers included in the composition for forming an organic electroluminescent element are added to the composition for forming an organic electroluminescent element) When the surface tension (unit: mN/m) of the mixture contained in the same amount as the amount contained is S1x, the following formula (3) is satisfied,

Sa-S1x>1.0 … (3)

A mixture of 100 parts by weight of the organic solvent and C2 parts by weight of the second surface modifier (that is, in the organic solvent, only all the second surface modifiers included in the composition for forming an organic electroluminescent element are added to the composition for forming an organic electroluminescent element) When the surface tension (unit: mN/m) of the mixture containing the same amount as the amount contained is S2x, it is characterized in that the following formula (4) is satisfied.

Sa-S2x<1.0 … (4)

A second aspect of the composition for forming an organic electroluminescent device of the present invention is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a third surface modifier and a fourth surface modifier, wherein the organic solvent alone The surface tension of Sa (mN / m), the surface tension of S1y (mN / m) when only 100 wt. ppm of the third surface modifier is dissolved in the organic solvent, and the fourth surface modifier alone in the organic solvent 100 wt. When the surface tension when dissolved in ppm is S2y (mN/m),

Sa-S1y>1.0, and Sa-S2y≤1.0

It is characterized in that it satisfies.

A third aspect of the composition for forming an organic electroluminescent device of the present invention is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a fifth surface modifier and a sixth surface modifier, wherein the surface tension of pure water is Sa' (mN / m), the surface tension when only 1000 ppm by weight of the fifth surface modifier was dissolved in pure water S1z (mN / m), the surface tension when only 1000 ppm by weight of the sixth surface modifier was dissolved in pure water When S2z (mN/m) is used, it is characterized in that the following formula (5) is satisfied.

Sa'>S1z>S2z . . . (5)

A fourth aspect of the composition for forming an organic electroluminescent device of the present invention is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a seventh surface modifier and an eighth surface modifier, wherein the seventh surface It is characterized in that the molecular weight of the modifier is 1000 or more, and the molecular weight of the eighth surface modifier is less than 1000.

<Surface modifier>

The surface modifier in the present invention refers to a material capable of controlling the surface tension of a liquid or the surface energy of a solid. By adding a small amount to a liquid, the surface modifier can impart functionality to the surface of the liquid after application of the liquid or to the surface of a solid obtained by application. Examples of the functions imparted here include liquid repellency, non-adhesiveness, wettability, smoothness, dispersibility, defoaming properties, and the like.

As a material that can be used as a surface modifier, a material that tends to segregate on the surface of the liquid is preferable, and specific examples thereof include silicon, fluorine-containing materials (polymers, oligomers, low molecules), paraffin, and surfactants.

A surfactant as used herein is a substance having an amphiphilic chemical structure having a hydrophilic moiety (group) and a hydrophobic moiety (group), and is a dispersing agent, a foaming agent, an antifoaming agent, an emulsifying agent, a food additive, a moisturizing agent, and an antistatic agent. , wettability improver, lubricant, rust preventive, etc. are used in a wide range of applications. Such surfactants are broadly classified into cationic, anionic, and amphoteric surfactants having a hydrophilic portion and nonionic surfactants. desirable.

In addition, these surfactants are sometimes classified according to the HLB value indicating the degree of affinity for water and oil. It is known that the HLB value takes a value from 0 to 20, and the closer to 0, the higher the lipophilicity (hydrophobicity), and the closer to 20, the higher the hydrophilicity. In the present invention, the HLB value is not particularly limited, but is preferably 1.5 or more and 18 or less from the viewpoint of solubility in organic solvents.

Specific examples of materials that can be used as the surface modifier of the present invention are shown below.

As a material containing silicon, it is polysiloxane; compounds obtained by partially ether-modified, ester-modified, or aralkyl-modified polysiloxanes; Compounds in which the methyl group of polysiloxane is substituted with an alkyl group; reactive polysiloxane obtained by adding a reactive group to polysiloxane; etc. can be mentioned.

Specifically, Shin-Etsu Chemical's KF series, X-22 series, KP series, Big Chemie's BYK series, Toray Dow Corning's SH series, SF series, BY series, Kyoesha Chemical's Polyflow KL series, etc. can be heard It is not particularly limited as long as it is a material described in the catalog provided by each company, but in particular, from the viewpoint of solubility in organic solvents and heat resistance, KF-351A, KF-945, KF-96, KF-6015, KF-6017 , KF-410, X22-821, FL-100, KF-414, KF-4917, X-22-7322, X-22-1877, KF-50, KF-6004, KF-889, KF-53, X -22-163, X-22-164, KP-124, KP-106, KP-623, KP-323, KP-327, KP-625, KP-341, KP-624, KP-310, KP-301 , KP-105 (manufactured by Shin-Etsu Chemical Co., Ltd.), BYK-361N, BYK-302, BYK-330, BYK-310, BYK-313, BYK-315N, BYK-370, BYK-322, BYK-323, BYK- 065, BYK-323, BYK-3440, BYK-345, BYK-3560, BYK-306, BYK-333 (made by Big Chemie), SH-200, SH-3771, SH-3746, BY16-036, SH-28 , SF-8428, 3Additive, 11Additive, 29Additive, 56Additive, 8526Additive, 501WAdditive, SF-8427, SF-8416, BY16-846, BY16-880, BY16-750, BY16-849, BY16-853, FZ-3785, SF -8411, BY16-870, BY16-869, SF-8417, BY16-205, SF-8413, BY16-880, SF-8421, SF-8416, SH-203, FS-1265, SH-510, SH-550 , SH-710, SH-8410, FZ-77, FS-1265 (manufactured by Toray Dow Corning), Polyflow KL-400, Polyflow KL-401, Polyflow KL-402, Polyflow KL-403, Polyflow KL -404 (manufactured by Kyoeisha Chemical Co., Ltd.) and the like are preferable.

As a material containing fluorine, it is fluorine-containing group oligomer; perfluoroalkyl group-containing oligomers; the oligomer having a UV reactive group; etc. can be mentioned.

Specifically, Fluorad series manufactured by 3M, Megafac (registered trademark) F series manufactured by DIC, Megafac R series, Suplon (registered trademark) S series manufactured by AGC Seimi Chemical Co., Ltd., Unidigm (registered trademark) manufactured by Daikin Kogyo Co., Ltd. Series, Demnum (registered trademark) series, Mitsubishi Material Denshi Kasei's Ftop EF series, Kyoesha Chemical's Polyflow series, Troy Chemical's Troisol S series, OMNOVA's PolyFox series, DuPont's Capstone (registered trademark) etc. can be mentioned. It is not particularly limited as long as it is a material described in the catalog provided by each company, but in particular from the viewpoint of solubility in organic solvents, FC-4430, FC-4432 (manufactured by 3M), F-444, F-477, F- 554, F-556, F-565, F-568, F-557, F-559, F-560, F-561, F-562, F-552, RS-75, RS-78, RS-56, F-410, F-510, F-553, F-430, F-555 (manufactured by DIC), S-242, S-243, S-420, S-611, S-651, S-386, S- 680, S-685 (manufactured by AGC Semichemical), No.7, No.50, No.54, No.75, No.77, No.85, No.90, No.95, No.99 Esha Kagaku Co., Ltd.), TG-5502, S-20, S-65, S-200 (Daikin Kogyo Co., Ltd.), EF-PP31, EF-PP33, EF-PP32, EF-L174 (Mitsubishi Material Denshi Kasei Co., Ltd.) ), S-366 (manufactured by Troy Chemical), PF-6320, PF-154, PF-159, PF-3320, PF-151, PF-652, PF-636 (manufactured by OMNOVA), FS-22, FS- 66, FS-83 (manufactured by DuPont), and the like are preferable.

Paraffin is a type of hydrocarbon-based compound and is an alkane compound having 20 or more carbon atoms. There are solid and liquid paraffin, and in general, the solid is called paraffin wax and the liquid is called paraffin oil. In the present invention, paraffin oil is considered to be suitable from the viewpoint of solubility in organic solvents.

Examples of the surfactant include cationic surfactants, anionic surfactants, amphoteric surfactants, and nonionic surfactants.

As a cationic surfactant, an amine type, a quaternary ammonium salt type, etc. are mentioned specifically,.

Examples of the amine type include aliphatic amines such as polyoxyethylene alkylamines and alkylamine salts, and heterocyclic amine salts such as alkyl imidazolines.

Examples of the quaternary ammonium salt type include alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkylbenzyldimethylammonium salts, and polydiallyldimethylammonium salts. In addition, chlorine salt types such as alkyltrimethylammonium chloride and dialkyldimethylammonium chloride, and non-chlorine types such as alkyldimethylethylammonium ethyl sulfate are exemplified.

Among these, amine-type or quaternary ammonium salt-type non-chlorine-type cationic surfactants are preferable because they do not contain elements that may deteriorate the performance of organic electroluminescent devices and are composed of non-metal elements. For example, Kao Corporation's Acetamine (registered trademark) series, Sanisol (registered trademark) series, Kotamine (registered trademark) series (acetamine 24, acetamine 86, Sanisol B-50, etc.), Daiichi Kogyo Seiya Catiogen (registered trademark) series made by Kussa, Charol (registered trademark) series (Catiogen ES-P, Catiogen DDM-PG, etc.), Nikkanon (registered trademark) series made by Nikka Chemical Co., Ltd., etc. are mentioned. .

Specific examples of the anionic surfactant include sulfuric acid ester type, phosphoric acid ester type, carboxylic acid type, and sulfonic acid type. As a salt, an anionic surfactant composed of a non-metal element and not containing an alkali metal such as sodium or potassium is preferable because it does not contain an element that may deteriorate the performance of the organic electroluminescent device. .

Specific examples of the sulfate ester type include alkyl sulfate ester salts, ethoxy sulfate ester salts, polyoxyethylene styrenated phenyl sulfate ester salts, polyoxyethylene alkyl ether sulfate ester salts, long-chain alcohol sulfate ester salts, and other sulfuric acid ester salts. can be heard

Specifically as a phosphoric acid ester type|mold, polyoxyethylene alkyl ether phosphoric acid ester (salt) etc. are mentioned.

Specific examples of the carboxylic acid type include fatty acid salts, polyoxyethylene alkyl ether acetates, polyoxyethylene alkyl ether sulfosuccinates, alkenyl succinates, polyacrylates, styrene-maleic acid copolymer ammonium salts, carboxymethyl cellulose salts, and the like. can be heard

Specific examples of the sulfonic acid type include sulfonic acid salts, sulfosuccinic acid salts, alkylbenzenesulfonic acid salts, alkanesulfonic acid salts, alpha olefin sulfonic acid salts, phenolsulfonic acid salts, naphthalenesulfonic acid sodium formalin condensates, and the like.

For example, Kaosha Emal (registered trademark) series, Lattemul (registered trademark) series, Neopelex (registered trademark) series, Pelex (registered trademark) series, Demoll (registered trademark) series, Poise (registered trademark) Series, Homogenol (registered trademark) series (Emal 20C, Lattemul WX, Neopelex GS, Pelex SS-L, Demoll NL, Poise 520, etc.), Daiichi Kogyo Seiyaku Co., Ltd. Monogen (registered trademark) series, Hightenol (registered trademark) series, Flysurf series, Neo Hightenol (registered trademark) series, Kali Soap series, Neogen (registered trademark) series, Neocall (registered trademark) series (Monogen Y-100, Hitenol 227L , Flysurf A215C, Neo Hytenol LS, Kali Soap HY, Neogen S-20F, Neocall P, etc.), Sunlex series manufactured by Nikka Chemical Co., Ltd., etc. are mentioned.

Specific examples of amphoteric surfactants include betaine type, amine oxide type, N-alkyl amino acid type, imidazoline type and the like. Among these, betaine type or imidazoline type amphoteric surfactants composed of non-metallic elements are preferable because they do not contain elements that may deteriorate the performance of the organic electroluminescent device.

Specific examples of the betaine type include amide betaines such as alkyl betaines and aliphatic amide betaines.

Specifically as an amine oxide type, an alkylamine oxide etc. are mentioned.

Specific examples of the N-alkylamino acid type include N-alkyl-β-aminopropionic acid salts and the like.

Specific examples of the imidazoline type include 2-alkyl imidazoline derivatives and the like.

Specific examples of nonionic surfactants include ether type, ester type, ether ester type, polyhydric alcohol type, amide type and polymer type. Since the nonionic surfactant is a compound having no charge, it does not hinder the flow of charge in the organic electroluminescent device. In addition, it does not contain a compound that may quench the light emission of the organic electroluminescent element. From this point of view, since the performance of the organic electroluminescent device does not change depending on the amount added, a nonionic surfactant is preferable as the surfactant.

The ether type is a compound having a skeleton in which a hydroxyl group such as a higher alcohol or alkylphenol is generally added with ethylene oxide, and specifically, polyoxyalkylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene alkyl phenyl ether , polyoxyethylene polyoxypropylene glycol, polyoxyethylene alkylamine, polyoxyethylene cumyl fuel ether, and the like.

For example, Emulgen (registered trademark) series made by Kaosha (Emulgen 123P, Emulgen 130K, Emulgen 150, Emulgen 430, Emulgen 409PV, Emulgen 705, Emulgen 707, Emulgen 709, Emulgen A- 60, Emergen A-500, etc.), Noigen (registered trademark) series, Antipros (registered trademark) series, Epan series, DKS-NL series (Neugen XL-40, Noigen XL- 80, Neugen XL-1000, Neugen TDS-70, Neugen LF-80X, Neugen LF-202N, Neugen LP-100, Neugen SO-70, Antipros M-9, Neugen EA-167, Neugen EN, Epan 410, Epan 710, DKS-NL-15, Neugen ET-128), Nippon Nyukazai Newcol (registered trademark) series (Newcol 2305, Newcol 2308, Newcol 2310, Newcol 2330, Newcol NT- 7. can

As the ester type, it is a compound having a skeleton in which polyhydric alcohols such as sorbitol, sorbitan, glycerin, and sucrose are ester-bonded with fatty acids, and sorbitol fatty acid esters, sorbitan fatty acid esters, glycerin fatty acid esters, sucrose fatty acid esters, sucrose derivatives, fatty acid esters, etc. can be heard

For example, Kao Corporation Leodol (registered trademark) series, Leodol Super series, Emazole (registered trademark) series, Excel (registered trademark) series (e.g. Leodol SP-L10, Leodol SP-P10, Leodol SP-S10V, Leodol SP-S20, Leodol SP-S30V, Leodol SP-O10V, Leodol SP-O30V, Leodol Super SP-L10, Leodol AO-10V, Emazole L-10V, Emazole O -10V, Emazole O-120V, Leodol MS-50, Leodol MS-60, Leodol MO-60, Leodol MS-165V, Excel S-95, Excel O-95R, Excel 200, etc.) or Daiichi Kogyo Seiyaku Co., Ltd. DKS-NL series, Neugen (registered trademark) ET series, Sorgen (registered trademark) series, DK Ester series, Monopet (registered trademark) series (eg DKS-NL-70, DKS-NL- 89, Neugen ET-89, Neugen ET-159, Sorgen 20V, Sorgen 40, DK Ester F160, DK Ester F90, DK Ester FA-10E, Monopet SB, Monopet SOA, etc.), Nippon New Kazaisa The first NuCall (registered trademark) series (eg, NewCall 20, NewCall 60, NewCall 80, NewCall 25, NewCall 65, NewCall 85, etc.) and the like.

The ether ester type is a skeleton obtained by adding ethylene oxide to an ester composed of a polyhydric alcohol such as sorbitol, sorbitan, glycerin, or sucrose and a fatty acid, and has both an ester bond and an ether bond in the molecule. Specifically, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene hydrogenated castor oil ether, etc. are mentioned.

For example, Leodol (registered trademark) TW series made by Kao Corporation, Leodol Super TW series, Leodol 400 series, Emanon (registered trademark) series (e.g. Leodol TW-L120, Leodol TW-P120, Leodol TW-S120V, Leodol TW-O120V, Leodol TW-O320V, Leodol Super TW-L120, Emanon 3199V, Emanon 3299RV, Emanon 4110, Emanon CH40, etc.) or Noigen made by Daiichi Kogyo Seiyaku Co., Ltd. registered trademark) HC series, Neugen DS series, Neugen GIS series, Neugen ES series, Sorgen (registered trademark) TW series (e.g. Neugen ES-99D, Neugen ES-129D, Neugen ES-148D, Neugen ES-168, Neugen DS-601, Sorgen TW80V, Sorgen TW20V, Neugen GIS-125, Neugen HC-400, etc.).

Examples of the polyhydric alcohol type include alkyl glucosides and alkyl polyglucosides. For example, Nonioside series (eg, Nonioside O-13) by Daiichi Kogyo Seiyaku Co., Ltd., etc. are mentioned.

The amide type has a fatty acid alkanolamide in which a hydrophobic group and a hydrophilic group are bonded by an amide bond, and specific examples thereof include alkylalkanolamides and olefin acid amides.

For example, Amit (registered trademark) series made by Kao Corporation, Aminon (registered trademark) series (eg Amit 102, Amit 105, Amit 302, Amit 320, Aminon PK-02S, etc.), Daiichi Amirachine series manufactured by Kogyo Seiyaku Co., Ltd., Dianol (registered trademark) series (eg, Dianol CDE, Dianol 300, Amirachine D, etc.), Newcall (registered trademark) series manufactured by Nippon Newkazai Co., Ltd. (eg, Newcol LA407, Newcol) OD420, Newcol TA420, etc.).

Specifically as a polymer type, polyvinyl pyrrolidone, a polyalkylene polyamine alkylene oxide adduct, a polyalkylene polyimine alkylene oxide adduct, etc. are mentioned.

Examples include Fitzcall (registered trademark) series and Discoll (registered trademark) series (eg, Discoll N508, Discoll N518, Fitzcall K-30, Fitzcall K-40, etc.) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. .

[First aspect of composition for forming organic electroluminescent device]

This aspect is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a first surface modifier and a second surface modifier,

If the surface tension of the organic solvent alone is Sa (mN / m),

The surface tension when only all the first surface modifiers are dissolved in the organic solvent at the same concentration (% by weight) as the concentration in the composition for forming an organic electroluminescent device is S1x (mN/m);

When only all the second surface modifiers are dissolved in the organic solvent at the same concentration (% by weight) as the concentration in the composition for forming an organic electroluminescent element, the surface tension is S2x (mN / m),

Sa-S1x＞1.0, and Sa-S2x＜1.0

It is characterized in that it satisfies.

In addition, when the surface tension of the organic solvent alone is Sa (mN / m),

The first surface modifier indicates that the surface tension (S1y) when 100 ppm by weight of the first surface modifier is dissolved in the organic solvent is Sa-S1y > 1.0,

The second surface modifier indicates that the surface tension (S2y) of Sa-S2y ≤ 1.0 when 100 ppm by weight of the two second surface modifiers is dissolved in the organic solvent.

That is, the present embodiment is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, at least one first surface modifier and at least one second surface modifier,

The surface tension (unit: mN/m) of the organic solvent is taken as Sa, and the content of the first surface modifier relative to 100 parts by weight of the organic solvent (when two or more types of first surface modifiers are used, the total content thereof) is C1 parts by weight, and the content of the second surface modifier relative to 100 parts by weight of the organic solvent (when two or more types of second surface modifiers are used, the total content thereof) is C2 parts by weight,

Each first surface modifier is a surface modifier that satisfies the following formula (1) when the surface tension (unit: mN/m) of a mixture in which 0.01 part by weight of the first surface modifier is dissolved in 100 parts by weight of an organic solvent is S1y. ego,

Sa-S1y>1.0 … (One)

Each second surface modifier is a surface modifier that satisfies the following formula (2) when the surface tension (unit: mN/m) of a mixture in which 0.01 part by weight of the second surface modifier is dissolved in 100 parts by weight of an organic solvent is S2y. ego,

Sa-S2y≤1.0 … (2)

A mixture of 100 parts by weight of the organic solvent and C1 parts by weight of the first surface modifier (that is, in the organic solvent, only all the first surface modifiers included in the composition for forming an organic electroluminescent element are added to the composition for forming an organic electroluminescent element) When the surface tension (unit: mN/m) of the mixture contained in the same amount as the amount contained is S1x, the following formula (3) is satisfied,

Sa-S1x>1.0 … (3)

A mixture of 100 parts by weight of the organic solvent and C2 parts by weight of the second surface modifier (that is, in the organic solvent, only all the second surface modifiers included in the composition for forming an organic electroluminescent element are added to the composition for forming an organic electroluminescent element) When the surface tension (unit: mN/m) of the mixture containing the same amount as the amount contained is S2x, it is characterized in that the following formula (4) is satisfied.

Sa-S2x<1.0 … (4)

<Charge injection transport material>

A charge injection and transport material is a material capable of efficiently injecting and transporting charges (holes and electrons) from an electrode, and is mainly used for a charge injection layer, a charge transport layer, and a light emitting layer in an organic electroluminescent device. In addition, although these materials are often used alone in each of the above layers, in order to control charge transport, a plurality of types may be mixed and used. Further, a low molecular material or a high molecular material may be used.

As the charge injection and transport material, known charge injection and transport materials for organic electroluminescent devices and organic photoconductors can be used. These charge injection transport materials are classified into hole injection transport materials and electron injection transport materials, and specific compounds thereof are exemplified below, but the present invention is not limited to these materials.

In addition, although a representative layer configuration of an organic electroluminescent device will be described later, the hole injection and transport material is mainly used for the hole injection layer, the hole transport layer and the light emitting layer, and the electron injection and transport material is mainly used for the light emitting layer, the hole blocking layer, the electron transport layer and the electron transport layer. used in the injection layer.

Examples of the hole injection transport material include oxides such as vanadium oxide (V ₂ O ₅ ) and molybdenum oxide (MoO ₂ ); inorganic p-type semiconductor materials; porphyrin compounds; N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-benzidine (TPD), N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine aromatic tertiary amine compounds such as (NPD); low molecular materials such as hydrazone compounds, quinacridone compounds, and styrylamine compounds; Polyaniline (PANI), polyaniline-camphorsulfonic acid (PANI-CSA), 3,4-polyethylenedioxythiophene/polystyrenesulfonate (PEDOT/PSS), poly(triphenylamine) derivative (Poly-TPD), polyvinylcarbazole polymer materials such as (PVCz), poly(p-phenylenevinylene) (PPV), and poly(p-naphthalenevinylene) (PNV); etc. can be mentioned.

The hole injection/transport material used for the hole injection layer has a lower highest point molecular orbital (HOMO) energy level than that of the hole injection/transport material used for the hole transport layer in that holes are injected and transported from the anode more efficiently. It is preferable to use the material.

As the hole injection and transport material used for the hole transport layer, it is preferable to use a material having a higher hole mobility than the hole injection and transport material used for the hole injection layer.

Further, in order to further improve the hole injection and transport properties, it is preferable to use as the hole injection and transport material a material obtained by further doping an acceptor in the above material. As the acceptor, a known acceptor material for organic electroluminescent devices can be used. Although these specific compounds are illustrated below, in this invention, it is not limited to these materials.

Examples of the acceptor material include inorganic materials such as Au, Pt, W, Ir, POCl ₃ , AsF ₆ , Cl, Br, I, vanadium oxide (V ₂ O ₅ ), and molybdenum oxide (MoO ₂ ); TCNQ (7,7,8,8,-tetracyanoquinodimethane), TCNQF4 (tetrafluorotetracyanoquinodimethane), TCNE (tetracyanoethylene), HCNB (hexacyanobutadiene), DDQ ( compounds having a cyano group such as dicyclodicyanobenzoquinone); compounds having a nitro group such as TNF (trinitrofluorenone) and DNF (dinitrofluorenone); and organic materials such as fluoranil, chloranil, and bromanyl. Among these, compounds having a cyano group such as TCNQ, TCNQF4, TCNE, HCNB, and DDQ are more preferable because they can increase the carrier concentration more effectively. Further, fluorine-containing organic salts such as 4-isopropyl-4-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate can also be used.

Examples of the electron injection transport material include inorganic materials that are n-type semiconductors; low molecular materials such as oxadiazole derivatives, triazole derivatives, thiopyrazine dioxide derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, diphenoquinone derivatives, fluorenone derivatives, and benzodifuran derivatives; and polymer materials such as poly(oxadiazole) (Poly-OXZ) and polystyrene derivative (PSS). In particular, examples of the electron injection transport material include fluorides such as lithium fluoride (LiF) and barium fluoride (BaF ₂ ), oxides such as lithium oxide (Li ₂ O), and the like.

As the electron injection/transport material used for the electron injection layer, the energy level of the lowest co-molecular orbital (LUMO) is higher than that of the electron injection/transport material used for the electron-transport layer in that the injection/transport of electrons from the cathode is performed more efficiently. It is preferable to use the material.

As the electron injection material used for the electron transport layer, it is preferable to use a material having higher electron mobility than the electron injection transport material used for the electron transport layer.

Further, in order to further improve the electron injection/transport property, it is preferable to use as the electron injection/transport material what is further doped with a donor to the above material. As the donor, a known donor material for organic electroluminescence devices can be used. Although these specific compounds are illustrated below, in this invention, it is not limited to these materials.

Examples of the donor material include inorganic materials such as alkali metals, alkaline earth metals, rare earth elements, Al, Ag, Cu, and In; Anilines, phenylenediamines, benzidines (N,N,N',N'-tetraphenylbenzidine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine, N, N'-di(naphthalen-1-yl)-N,N'-diphenylbenzidine, etc.), triphenylamines (triphenylamine, 4,4'4"-tris(N,N-diphenyl-amino)tri Phenylamine, 4,4'4"-tris(N-3-methylphenyl-N-phenyl-amino)triphenylamine, 4,4'4"-tris(N-(1-naphthyl)-N-phenylamino ) Aromatic tertiary amines such as triphenylamine, etc.) and triphenyldiamines (N,N'-di-(4-methyl-phenyl)-N,N'-diphenyl-1,4-phenylenediamine) Compounds in the skeleton; Condensed polycyclic compounds such as phenanthrene, pyrene, perylene, anthracene, tetracene, and pentacene (however, the condensed polycyclic compound may have a substituent); TTF (tetrathiafulvalene), dibenzo organic materials such as furan, phenothiazine, carbazole, etc. Among these, compounds having aromatic tertiary amines in their skeletons, condensed polycyclic compounds, and alkali metals are more effective because they can increase the carrier concentration more effectively. desirable.

<Organic Solvent>

The organic solvent used in the present invention is a volatile liquid component used to form a layer containing a charge injection and transport material by wet film formation, and is particularly limited as long as it is an organic solvent that dissolves the charge injection and transport material well. It doesn't work.

Examples of preferred organic solvents include alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane;

aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, and tetralin;

halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene;

Aromatic glycols, such as 2-phenoxyethyl acetate, benzyl glycol, and phenyl glycol;

1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, ethylanisole, propylphenyl ether, butylphenyl ether, methylanisole, dimethylanisole, ethylanisole, diethylanisole, propylanisole Sol, butylanisole, pentylanisole, methylnaphthylanisole, octylanisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2 aromatic ethers such as ,4-dimethylanisole, diphenyl ether, and 3-phenoxytoluene;

aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate, t-butyl benzoate, and isoamyl benzoate;

alicyclic ketones such as cyclohexanone, cyclooctanone, and pencon;

alicyclic alcohols such as cyclohexanol and cyclooctanol;

aliphatic ketones such as methyl ethyl ketone and dibutyl ketone;

aliphatic alcohols such as butanol and hexanol;

Ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA), triethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol di-n- aliphatic ethers such as butyl ether; etc. can be mentioned.

From the viewpoint of solubility, film formation uniformity, and device characteristics, at least one selected from alkanes, aromatic hydrocarbons, aromatic esters and aromatic ethers is preferred, and aromatic esters and/or aromatic ethers are more preferred. Especially preferably, n-butyl benzoate, t-butyl benzoate, isoamyl benzoate, diphenyl ether, and 2,4-dimethylanisole are mentioned. By using these, there is a tendency that desirable viscosities and boiling points can be obtained in the wet film forming process.

These organic solvents may be used individually by one type or two or more types may be used in any combination and ratio, but aromatic hydrocarbons, aromatic esters, and aromatic ethers do not change the solubility of the material, Since it is possible to change the surface tension and viscosity of , it is preferable to use them in combination.

The boiling point of the organic solvent (when two or more organic solvents are used in combination as the organic solvent, the weighted average value calculated from the content and boiling point of each organic solvent combined is taken as the boiling point. The same below) is usually 80 °C or higher, preferably 100 °C or higher, more preferably 150 °C or higher, particularly preferably 200 °C or higher, and usually 350 °C or lower, preferably 280 °C or lower, more preferably 250 °C or lower. When the amount is equal to or greater than the lower limit, evaporation of the organic solvent from the composition is suppressed during wet film formation, and film formation stability tends to be obtained. Moreover, when it is below the above upper limit, the original characteristics of the organic film tend to be obtained after drying.

The surface tension of the organic solvent (measurement method will be described later) is not particularly limited as long as it can be applied in the wet film forming method, but from the viewpoint of good applicability, the value at room temperature is usually 20 mN/m or more, It is preferably 25 mN/m or more, and is usually 45 mN/m or less, preferably 40 mN/m or less, and more preferably 38 mN/m or less.

The viscosity of the organic solvent is not limited as long as it can be injected from the coating device, but from the viewpoint of easy filtration, it is usually 1 cP or more, preferably 2 cP or more, and the value at room temperature is usually 30 cP or less, Preferably it is 25 cP or less, More preferably, it is 20 cP or less.

<First surface modifier>

The first surface modifier refers to the surface tension of the organic solvent alone used in the composition for forming an organic electroluminescent device (when a mixture of two or more organic solvents is used as the organic solvent, the surface tension of the mixture is used. Same hereafter) is Sa (mN/m), and 100 parts by weight of the first surface modifier is dissolved in the organic solvent, that is, 0.01 part by weight of the first surface modifier is dissolved in 100 parts by weight of the organic solvent. When the surface tension of is S1y, it is a surface modifier that satisfies Sa-S1y>1.0.

Among the plurality of surface modifiers included in the composition for forming an organic electroluminescent element, the surface modifiers that satisfy the above conditions are all first surface modifiers, include at least one type of first surface modifier as the first surface modifier, and include two types of first surface modifiers. The above 1st surface modifier may also be included.

Further, all first surface modifiers (that is, when two or more types of first surface modifiers are used as the first surface modifiers in a certain ratio, it means a mixture of the two or more types of first surface modifiers in that ratio) Sa-S1x>1.0 is satisfied when the surface tension when dissolved in the organic solvent at the same concentration (wt%) as that in the composition for forming an organic electroluminescent element is S1x (mN/m).

In the present invention, the surface tension is measured by the plate method (Wilhelmy method) at room temperature using an automatic surface tensiometer (for example, CBVP-Z type manufactured by Kyowa Science and Technology Co., Ltd.). Platinum is used for the plate in this measurement, and foreign matter on the surface is removed by direct fire immediately before measurement, and the measurement is carried out.

As the first surface modifier, specifically, among the above-mentioned surface modifiers, materials containing silicon, materials containing fluorine, paraffin, etc. (any of polymers, oligomers, and low molecules may be used) are suitably used. Among them, a material containing silicon and/or a material containing fluorine is particularly suitable. In particular, polysiloxanes; compounds obtained by partially ether-modified, ester-modified, or aralkyl-modified polysiloxanes; Compounds in which the methyl group of polysiloxane is substituted with an alkyl group; fluorine-containing oligomers; perfluoroalkyl group-containing oligomers; etc. are preferred. These materials are preferable from the viewpoints of their influence on materials used for organic films, heat resistance, and affinity to organic solvents.

The content of the first surface modifier in the composition for forming an organic electroluminescent element is based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent element, from the viewpoint of solubility in the solvent and functionality as a surface modification. As such, it is preferably 1 wtppm or more, more preferably 10 wtppm or more, still more preferably 50 wtppm or more, preferably 50000 wtppm or less, more preferably 10000 wtppm or less, still more preferably is less than 1000 ppm by weight.

In addition, when two or more types of first surface modifiers are used as the first surface modifier, the total content of all the first surface modifiers in the composition for forming an organic electroluminescent element is Based on the amount of the organic solvent contained as a reference value, it is preferably 1 ppm by weight or more, more preferably 10 ppm by weight or more, still more preferably 50 ppm by weight or more, preferably 50000 ppm by weight or less, more preferably is 10000 ppm by weight or less, more preferably 1000 ppm by weight or less.

When it is below the above upper limit value, solubility in solvents can be ensured, and when it is above the above lower limit value, the function as a surface modifier can be expressed.

<Second surface modifier>

The second surface modifier has a surface tension of Sa (mN/m) of the organic solvent alone used in the composition for forming an organic electroluminescent device, and 100 ppm by weight of the second surface modifier in the organic solvent, that is, the organic solvent. When S2y is the surface tension when 0.01 part by weight of the second surface modifier is dissolved in 100 parts by weight of the solvent, the surface modifier satisfies Sa-S2y≤1.0.

Among the plurality of surface modifiers included in the composition for forming an organic electroluminescent device, the surface modifiers that satisfy the above conditions are all second surface modifiers, include one or more types of second surface modifiers as the second surface modifier, and As the surface modifier, two or more types of second surface modifiers may be included.

In addition, all the second surface modifiers (that is, when two or more types of second surface modifiers are used as the second surface modifiers in a certain ratio, it means a mixture of the two or more types of second surface modifiers in that ratio) Sa-S2x<1.0 is satisfied when the surface tension when dissolved in the organic solvent at the same concentration (wt%) as that in the composition for forming an organic electroluminescent element is S2x (mN/m).

That is, the first surface modifier can lower the surface tension of the organic solvent by being mixed with the organic solvent, and the second surface modifier, when mixed with the organic solvent, has a function of lowering the surface tension of the organic solvent on the first surface. A surface modifier that is weaker than a modifier or does not have a function of lowering the surface tension of an organic solvent.

As the second surface modifier, specifically, among the surface modifiers described above, a nonionic surfactant is preferably used. Among the nonionic surfactants, ether-type, ester-type, or ether/ester-type nonionic surfactants are particularly preferred. These materials are preferred from the standpoint of being able to maintain the performance of the organic electroluminescent element since the performance of the organic electroluminescent element does not change depending on the amount added.

The content of the second surface modifier in the composition for forming an organic electroluminescent element is preferably 1, based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent element, from the viewpoint of solubility in the solvent. It is more than 10 weight ppm, more preferably 10 weight ppm or more, still more preferably 50 weight ppm or more, preferably 50000 weight ppm or less, more preferably 10000 weight ppm or less, still more preferably 1000 weight ppm or less.

In addition, when two or more types of second surface modifiers are used as the second surface modifier, the total content of all the second surface modifiers in the composition for forming an organic electroluminescent element is in the composition for forming an organic electroluminescent element. Based on the amount of the organic solvent contained as a reference value, it is preferably 1 ppm by weight or more, more preferably 10 ppm by weight or more, still more preferably 50 ppm by weight or more, preferably 50000 ppm by weight or less, more preferably It is 10000 weight ppm or less, More preferably, it is 1000 weight ppm or less.

When it is below the above upper limit value, solubility in solvents can be ensured, and when it is above the above lower limit value, the function as a surface modifier can be expressed.

In addition, the surface tension of pure water is Sa' (mN/m), and all the first surface modifiers in the pure water (that is, when two or more kinds of first surface modifiers are used as the first surface modifiers in a certain ratio, those 2 The surface tension when only 1000 ppm by weight, that is, 0.1 part by weight of the first surface modifier is dissolved in 100 parts by weight of pure water is S1z' (mN / m), and all the second surface modifiers in pure water (that is, when two or more types of second surface modifiers are used as second surface modifiers in a certain ratio, in the ratio of those two or more types of second surface modifiers mixture) alone is 1000 ppm by weight, that is, when 0.1 part by weight of the second surface modifier is dissolved in 100 parts by weight of pure water, the surface tension is S2z' (mN / m), Sa' > S1z' > S2z It is desirable to satisfy '.

By satisfying this requirement, there is a tendency that good film thickness uniformity can be obtained when the organic film is wet-formed within the barrier rib.

Further, the definitions of pure water, Sa', S1z', and S2z' have the same meanings as those of pure water, Sa', S1z, and S2z shown in the third aspect of the composition for forming an organic electroluminescent device of the present invention described later.

<Combination of first surface modifier and second surface modifier>

The combination of the first surface modifier and the second surface modifier is not particularly limited as long as the effect of the present invention is not significantly impaired. In particular, a combination of a silicone-containing material of the first surface modifier and an ether type surfactant of the second surface modifier, a combination of a silicone-containing material of the first surface modifier and an ether/ester type surfactant of the second surface modifier and the like are preferable from the viewpoint of the degree of influence on the organic electroluminescent element.

The content ratio (weight ratio) of the first surface modifier and the second surface modifier in the composition for forming an organic electroluminescent device is not particularly limited. The ratio C2/C1 of the total content C1 of the first surface modifier and the total content C2 of the second surface modifier is preferably 0.05 or more, more preferably 0.1 or more, still more preferably 0.5 or more, preferably 500 or less, more preferably 100 or less, still more preferably 50 or less.

When it is equal to or more than the lower limit, adsorption of the second surface modifier in the drying step tends to occur as expected, and when it is equal to or less than the upper limit, the effect of lowering the surface tension of the first surface modifier tends to be obtained.

<Effect of using the first surface modifier and the second surface modifier>

The mechanism by which the composition for forming an organic electroluminescent device contains the first surface modifier and the second surface modifier to obtain good film thickness and flatness when the organic film is wet-formed in the barrier rib is estimated as follows.

Here, the flatness is an index indicating how flat the organic film is, and in the present invention, represents the ratio of the area having a film thickness difference of 5 nm or less to the entire light emitting area. Such flatness deteriorates when defects such as occurrence of orange peel, occurrence of pinholes, and occurrence of unevenness occur. The cause of these defects is the evaporation of the organic solvent, the change in viscosity and the change in surface tension accompanying the evaporation of the organic solvent, which occur during drying of the coating film. Since the evaporation of the organic solvent and the change in viscosity largely depend on the material, the deterioration of the flatness is usually suppressed by reducing the change in surface tension of the solution as much as possible, that is, by lowering and equalizing the surface tension with a surface modifier.

In this case, deterioration of the flatness of the organic film in the central portion of the partition can be suppressed by lowering and equalizing the surface tension of the solution, but the flatness of the organic film at the edge of the partition, which is a region near the partition, deteriorates. This is because, since pinning of the solution occurs at the edge of the partition, the wetting of the solution to the partition is exaggerated due to the coffee stain effect, and the film thickness of the organic film at the edge of the partition greatly changes.

On the other hand, in the present invention, the function of the first surface modifier is to lower and equalize the surface tension by segregating on the surface of the solution, and the function of the second surface modifier to lower the surface tension for dispersing in the solution is to reduce the surface tension of the first surface modifier. Although weaker than that of the surface modifier, it is thought to have an effect of adsorbing to the first surface modifier and changing the function of the first surface modifier. That is, it is estimated that both surface modifiers act as follows in the process of film formation.

First, deterioration in the flatness of the organic film at the central portion of the barrier rib is suppressed by the first surface modifier that equalizes the surface tension of the solution. Then, when it transfers to a drying process, since it dries from the edge part of a partition, the density|concentration of the 1st surface modifier and the 2nd surface modifier of a partition edge part increases. At this time, the mean free process of the first surface modifier and the second surface modifier is shortened, the probability of contact between the two is increased, and the second surface modifier is easily adsorbed to the first surface modifier. The first surface modifier to which the second surface modifier is adsorbed suppresses a function of lowering the surface tension of the solution. Therefore, a decrease in the surface tension of the solution at the edge of the partition, which dries quickly, is suppressed, and as a result, wetting to the partition is suppressed, and the change in film thickness of the organic film at the edge of the partition is reduced. At this time, since the concentration of both surface modifiers in the central portion of the barrier rib is slower than that of the edge portion of the barrier rib, the concentration of both surface modifiers is not high, so the surface tension of the solution is maintained and the deterioration of flatness is suppressed. In addition, as drying progresses, the concentration of both surface modifiers in the central part of the partition increases, as in the edge of the partition, and the decrease in surface tension of the solution is suppressed. Since this is in a state where this is applied, it is presumed that the difference in film thickness of the organic film in the barrier rib is reduced by this tension, and deterioration in flatness can be suppressed.

Based on the above estimation, [Sa-S1x] is more preferably 1.2 or more, still more preferably 1.5 or more, particularly preferably 1.8 or more, and most preferably 2.0 or more, in view of the high surface tension lowering function of the solution. to be. In addition, [Sa-S2x] has a weaker surface tension lowering function than the first surface modifier and has a high effect of suppressing the surface tension lowering of the partition edge portion during drying, so it is more preferably 0.8 or less, still more preferably 0.8 or less. 0.6 or less, particularly preferably 0.5 or less.

[Second aspect of composition for forming organic electroluminescent device]

This embodiment is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a third surface modifier and a fourth surface modifier,

The surface tension of the organic solvent alone is set to Sa (mN/m), and the surface tension when only 100 ppm by weight of the third surface modifier is dissolved in the organic solvent is set to S1y (mN/m). If the surface tension when only the fourth surface modifier is dissolved at 100 ppm by weight is S2y (mN/m),

Sa-S1y>1.0, and Sa-S2y≤1.0

meets

The charge injection and transport material and the organic solvent are the same as those of the first aspect of the composition for forming an organic electroluminescent device described above.

<Third surface modifier>

The third surface modifier has a surface tension of Sa (mN/m) of the organic solvent alone used in the composition for forming an organic electroluminescent device, and one kind of the corresponding third surface modifier (ie, organic electroluminescent device) is added to the organic solvent. When two or more types of third surface modifiers are used in the forming composition, it means that each of the two or more types of third surface modifiers are individually used) in an amount of 100 ppm by weight, that is, 100 parts by weight of the corresponding organic solvent. When S1y is the surface tension when 0.01 part by weight of the surface modifier is dissolved, it is a surface modifier that satisfies Sa-S1y>1.0.

As the third surface modifier, specifically, among the above-mentioned surface modifiers, materials containing silicon, materials containing fluorine, etc. (any of polymers, oligomers, and low molecules may be used) are suitably used as the third surface modifier. do. Among them, polymers containing silicone are particularly suitable. In particular, polysiloxanes; compounds obtained by partially ether-modified, ester-modified, or aralkyl-modified polysiloxanes; A compound obtained by substituting an alkyl group for a methyl group of polysiloxane; is preferred. These materials are preferable from the viewpoints of their influence on materials used for organic films, heat resistance, and affinity to organic solvents.

The content of the third surface modifier in the composition for forming an organic electroluminescent element is based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent element, from the viewpoint of solubility in the solvent and functionality as a surface modification. As such, it is usually 1 ppm by weight or more, preferably 10 ppm by weight or more, more preferably 50 ppm by weight or more, and usually 50000 ppm by weight or less, preferably 10000 ppm by weight or less, and more preferably 1000 ppm by weight or less. .

When it is below the above upper limit value, solubility in solvents can be ensured, and when it is above the above lower limit value, the function as a surface modifier can be expressed.

<Fourth surface modifier>

In the fourth surface modifier, the surface tension of the organic solvent alone used in the composition for forming an organic electroluminescent device is Sa (mN/m), and one kind of the corresponding fourth surface modifier (ie, an organic electroluminescent device) is added to the organic solvent. When two or more types of fourth surface modifiers are used in the forming composition, it means that each of the two or more types of fourth surface modifiers are individually used) in an amount of 100 ppm by weight, that is, 100 parts by weight of the corresponding organic solvent. If S2y is the surface tension when 0.01 parts by weight of the surface modifier is dissolved, it is a surface modifier that satisfies Sa-S2y≤1.0.

That is, the third surface modifier can lower the surface tension of the organic solvent by being mixed with the organic solvent, and the fourth surface modifier has a function of lowering the surface tension of the organic solvent when mixed with the organic solvent. It is a surface modifier that is weaker than a surface modifier or does not have a function of lowering the surface tension of an organic solvent.

As the fourth surface modifier, specifically, among the surface modifiers described above, a nonionic surfactant is preferably used. Among the nonionic surfactants, ether-type, ester-type, or ether/ester-type nonionic surfactants are particularly preferred. These materials are preferred from the standpoint of being able to maintain the performance of the organic electroluminescent element since the performance of the organic electroluminescent element does not change depending on the amount added.

The content of the fourth surface modifier in the composition for forming an organic electroluminescent element is usually 1 ppm by weight, based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent element, from the viewpoint of solubility in the solvent. or more, preferably 10 wtppm or more, more preferably 50 wtppm or more, and usually 50000 wtppm or less, preferably 10000 wtppm or less, and more preferably 1000 wtppm or less.

When it is below the above upper limit value, solubility in solvents can be ensured, and when it is above the above lower limit value, the function as a surface modifier can be expressed.

<Effect of using the third surface modifier and the fourth surface modifier>

The effect of using the third surface modifier and the fourth surface modifier and the mechanism thereof are the same as those of using the first surface modifier and the second surface modifier. Further, the preferred ranges of [Sa-S1y] and [Sa-S2y] are the same as the preferred ranges of [Sa-S1x] and [Sa-S2x] in the first aspect of the composition for forming an organic electroluminescent element, respectively. Do.

[Third aspect of composition for forming organic electroluminescent device]

This embodiment is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a fifth surface modifier and a sixth surface modifier,

When the surface tension of pure water is Sa' (mN/m), the surface tension when only 1000 ppm by weight of the fifth surface modifier is dissolved in pure water is S1z (mN/m), and when only 1000 ppm by weight of the sixth surface modifier is dissolved in pure water When the surface tension of is S2z (mN / m),

Sa'>S1z>S2z . . . (5)

It is characterized in that it satisfies.

That is, the present embodiment is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a fifth surface modifier and a sixth surface modifier,

The surface tension (unit: mN/m) of pure water is Sa', the surface tension (unit: mN/m) of a mixture of 100 parts by weight of pure water and 0.1 part by weight of the fifth surface modifier is S1z, and 100 parts by weight of pure water When S2z is the surface tension (unit: mN/m) of a mixture of parts by weight and 0.1 part by weight of the sixth surface modifier, the following formula (5) is characterized.

Sa'>S1z>S2z . . . (5)

Here, pure water refers to water with high purity that does not contain or hardly contains impurities. An indicator of the purity of pure water is evaluated by the specific resistance or conductivity of pure water, and a pure water is defined as 10 MΩ·cm or more.

The charge injection and transport material and the organic solvent are the same as those of the first aspect of the composition for forming an organic electroluminescent device described above.

<Fifth surface modifier>

For the fifth surface modifier, when the surface tension of pure water is Sa' (mN/m) and the surface tension when only 1000 ppm by weight of the fifth surface modifier is dissolved in pure water is S1z (mN/m), Sa'> It is a surface modifier that satisfies S1z and satisfies S1z>S2z when the surface tension when only 1000 ppm by weight of the sixth surface modifier is dissolved in pure water is S2z (mN/m).

The fifth surface modifier is the surface tension of the organic solvent alone used in the composition for forming an organic electroluminescent element (when a mixture of two or more organic solvents is used as the organic solvent, it means the surface tension of the mixture) . hereinafter the same) is Sa (mN/m), and 100 parts by weight of the fifth surface modifier is dissolved in the organic solvent, that is, 0.01 part by weight of the fifth surface modifier is dissolved in 100 parts by weight of the organic solvent. When the surface tension at the time is S1y, it is preferable to satisfy Sa-S1y>1.0.

Among the plurality of surface modifiers included in the composition for forming an organic electroluminescent device, all fifth surface modifiers preferably satisfy the above conditions. As the fifth surface modifier, one or more kinds of fifth surface modifiers are included, and two or more kinds of fifth surface modifiers may be included.

As the fifth surface modifier, specifically, among the above-mentioned surface modifiers, materials containing silicon, materials containing fluorine, etc. (any of polymers, oligomers, and low molecules may be used) are suitably used as the fifth surface modifier. do. Among them, polymers containing silicone are particularly suitable. In particular, polysiloxanes; compounds obtained by partially ether-modified, ester-modified, or aralkyl-modified polysiloxanes; A compound obtained by substituting an alkyl group for a methyl group of polysiloxane; is preferred. These materials are preferable from the viewpoints of their influence on materials used for organic films, heat resistance, and affinity to organic solvents.

The content of the fifth surface modifier in the composition for forming an organic electroluminescent element is based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent element, from the viewpoint of solubility in the solvent and functionality as a surface modification. As such, it is usually 1 ppm by weight or more, preferably 10 ppm by weight or more, more preferably 50 ppm by weight or more, and usually 50000 ppm by weight or less, preferably 10000 ppm by weight or less, and more preferably 1000 ppm by weight or less. .

In addition, when two or more types of fifth surface modifiers are used as the fifth surface modifier, the total content of all the fifth surface modifiers in the composition for forming an organic electroluminescent element is in the composition for forming an organic electroluminescent element. Based on the amount of the organic solvent contained as a reference value, it is preferably 1 ppm by weight or more, more preferably 10 ppm by weight or more, still more preferably 50 ppm by weight or more, preferably 50000 ppm by weight or less, more preferably is 10000 ppm by weight or less, more preferably 1000 ppm by weight or less.

When it is below the above upper limit value, solubility in solvents can be ensured, and when it is above the above lower limit value, the function as a surface modifier can be expressed.

<Sixth surface modifier>

For the sixth surface modifier, the surface tension of pure water is Sa' (mN/m), and the surface tension when only 1000 ppm by weight of the sixth surface modifier is dissolved in pure water is S2z (mN/m), Sa'> It is a surface modifier that satisfies S2z and satisfies S1z > S2z when the surface tension when only 1000 ppm by weight of only the fifth surface modifier is dissolved in pure water is S1z (mN/m).

That is, the fifth surface modifier and the sixth surface modifier can reduce the surface tension of pure water by being mixed with pure water, and the fifth surface modifier has a function of reducing the surface tension of pure water when mixed with pure water. It is weak compared to surface modifiers.

In the sixth surface modifier, the surface tension of the organic solvent alone used in the composition for forming an organic electroluminescent device is Sa (mN/m), and the sixth surface modifier is added to the organic solvent in an amount of 100 ppm by weight, that is, If S2y is the surface tension when 0.01 part by weight of the sixth surface modifier is dissolved in 100 parts by weight of the organic solvent, Sa-S2y ≤ 1.0 is preferably satisfied.

Among the plurality of surface modifiers included in the composition for forming an organic electroluminescent element, all of the sixth surface modifiers preferably satisfy the above conditions. As the sixth surface modifier, one or more types of sixth surface modifiers are included, and two or more types of sixth surface modifiers may be included.

Specifically, as the sixth surface modifier, a nonionic surfactant is preferably used among the surface modifiers described above. Among the nonionic surfactants, ether-type, ester-type, or ether/ester-type nonionic surfactants are particularly preferred. These materials are preferred from the standpoint of being able to maintain the performance of the organic electroluminescent element since the performance of the organic electroluminescent element does not change depending on the amount added.

The content of the sixth surface modifier in the composition for forming an organic electroluminescent element is usually 1 ppm by weight, based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent element, from the viewpoint of solubility in the solvent. or more, preferably 10 wtppm or more, more preferably 50 wtppm or more, and usually 50000 wtppm or less, preferably 10000 wtppm or less, and more preferably 1000 wtppm or less.

In addition, when two or more types of sixth surface modifiers are used as the sixth surface modifier, the total content of all the sixth surface modifiers in the composition for forming an organic electroluminescent element is in the composition for forming an organic electroluminescent element. Based on the amount of the organic solvent contained as a reference value, it is preferably 1 ppm by weight or more, more preferably 10 ppm by weight or more, still more preferably 50 ppm by weight or more, preferably 50000 ppm by weight or less, more preferably is 10000 ppm by weight or less, more preferably 1000 ppm by weight or less.

When it is below the above upper limit value, solubility in solvents can be ensured, and when it is above the above lower limit value, the function as a surface modifier can be expressed.

<Effect of using the fifth surface modifier and the sixth surface modifier>

In the composition for forming an organic electroluminescent element, the fifth surface modifier having a lower hydrophilicity and lowering and equalizing the surface tension of the organic solvent solution and the function of changing the surface tension of the organic solvent having a higher hydrophilicity are the fifth surface modifier. By containing the sixth surface modifier, which is weaker than that of the fifth surface modifier but has an effect of adsorbing to the fifth surface modifier and changing the function of the fifth surface modifier, good film thickness uniformity can be obtained when an organic film is wet-formed inside the barrier rib. The existing mechanism is presumed as follows.

First, deterioration of the flatness of the organic film at the central portion in the partition wall is suppressed by the fifth surface modifier that equalizes the surface tension of the solution. In addition, the sixth surface modifier, which further lowers the surface tension of pure water, that is, has high hydrophilicity, is adsorbed to the edge of the barrier rib, thereby making the wettability of the barrier rib more hydrophilic. When the barrier rib becomes hydrophilic, the solution containing the organic solvent becomes difficult to wet, suppressing pinning, and as a result, wetting to the barrier rib is suppressed. Since wetting of the barrier rib is suppressed and drying progresses while the decrease in surface tension is uniformed, deterioration in flatness of the organic film remains suppressed. In addition, as drying progresses, peening occurs at the edge of the partition wall anyway because the edge of the partition wall is dried quickly. It is assumed that a high film is formed.

[Fourth aspect of composition for forming organic electroluminescent device]

This embodiment is a composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a seventh surface modifier and an eighth surface modifier,

The seventh surface modifier has a molecular weight of 1000 or more, and the eighth surface modifier has a molecular weight of less than 1000.

The charge injection and transport material and the organic solvent are the same as those of the first aspect of the composition for forming an organic electroluminescent device described above.

<Seventh surface modifier>

The seventh surface modifier is a surface modifier having a molecular weight of 1000 or more. When the seventh surface modifier is a polymer, it refers to a surface modifier having a weight average molecular weight of 1000 or more. Moreover, since solubility to a solvent will fall extremely when molecular weight (weight average molecular weight in the case of a polymer) is too large, Preferably it is 100000 or less, Especially preferably, it is 10000 or less.

As the seventh surface modifier, specifically, among the above-mentioned surface modifiers, materials containing silicon, materials containing fluorine, etc. (any of polymers, oligomers, and low molecules may be used) are suitably used as the seventh surface modifier. do. Among them, polymers containing silicone are particularly suitable. In particular, polysiloxanes; compounds obtained by partially ether-modified, ester-modified, or aralkyl-modified polysiloxanes; A compound obtained by substituting an alkyl group for a methyl group of polysiloxane; is preferred.

The content of the seventh surface modifier in the composition for forming an organic electroluminescent element is based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent element, from the viewpoint of solubility in the solvent and functionality as a surface modification. As such, it is usually 1 ppm by weight or more, preferably 10 ppm by weight or more, more preferably 50 ppm by weight or more, and usually 50000 ppm by weight or less, preferably 10000 ppm by weight or less, and more preferably 1000 ppm by weight or less. .

In addition, when two or more types of seventh surface modifiers are used as the seventh surface modifier, the total content of all seventh surface modifiers in the composition for forming an organic electroluminescent element is in the composition for forming an organic electroluminescent element. Based on the amount of the organic solvent contained as a reference value, it is usually 1 ppm by weight or more, preferably 10 ppm by weight or more, more preferably 50 ppm by weight or more, and usually 50000 ppm by weight or less, preferably 10000 ppm by weight or less, more Preferably it is 1000 weight ppm or less.

When it is below the above upper limit value, solubility in solvents can be ensured, and when it is above the above lower limit value, the function as a surface modifier can be expressed.

<Eighth surface modifier>

The eighth surface modifier is a surface modifier having a molecular weight of less than 1000.

Specifically, as the eighth surface modifier, a nonionic surfactant is preferably used among the surface modifiers described above. Among the nonionic surfactants, ether-type, ester-type, or ether/ester-type nonionic surfactants are particularly preferred.

The content of the eighth surface modifier in the composition for forming an organic electroluminescent element is usually 1 ppm by weight, based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent element, from the viewpoint of solubility in the solvent. or more, preferably 10 wtppm or more, more preferably 50 wtppm or more, and usually 50000 wtppm or less, preferably 10000 wtppm or less, and more preferably 1000 wtppm or less.

In addition, when two or more types of eighth surface modifiers are used as the eighth surface modifier, the total content of all the eighth surface modifiers in the composition for forming an organic electroluminescent device is included in the composition for forming an organic electroluminescent device. The amount of the organic solvent used as a reference value is preferably 1 ppm by weight or more, more preferably 10 ppm by weight or more, even more preferably 50 ppm by weight or more, preferably 50000 ppm by weight or less, and more preferably 10000 ppm by weight or less. It is weight ppm or less, More preferably, it is 1000 weight ppm or less.

When it is below the above upper limit value, solubility in solvents can be ensured, and when it is above the above lower limit value, the function as a surface modifier can be expressed.

<Effect of using the seventh surface modifier and the eighth surface modifier>

The mechanism for obtaining good film thickness uniformity when the organic film is wet-formed in the barrier rib by including the seventh surface modifier and the eighth surface modifier in the composition for forming an organic electroluminescent element is estimated as follows.

In the present invention, the eighth surface modifier having a molecular weight of less than 1000 has a strong function of suppressing deterioration of flatness because the molecules are more arranged on the surface of the liquid due to its low molecular weight. On the other hand, by using the seventh surface modifier having a molecular weight of 1000 or more, molecular arrangement is difficult to occur on the surface of the liquid, but the concentration of the seventh surface modifier increases during drying and the viscosity increases rapidly, so that wetting of the solution to the partition wall is suppressed. It is thought to have the ability to From this point of view, since the flatness of the organic film in the barrier rib is improved by the eighth surface modifier and the increase in film thickness due to wetting of the edge of the barrier rib is suppressed by the seventh surface modifier, the flatness is thought to be improved.

[Aspects common to the first to fourth aspects of the composition for forming an organic electroluminescent element]

Hereinafter, aspects common to the first to fourth aspects of the composition for forming an organic electroluminescent element of the present invention will be described.

(Composition of Composition for Forming Organic Electroluminescent Device)

In the composition for forming an organic electroluminescent device of the present invention, the content of the charge injection and transport material is usually 0.1 part by weight or more, based on the amount of the organic solvent contained in the composition for forming an organic electroluminescent device as a reference value (100 parts by weight). , preferably 0.5 parts by weight or more, more preferably 1.0 parts by weight or more, and usually 50 parts by weight or less, preferably 20 parts by weight, more preferably 10 parts by weight or less.

In the composition for forming an organic electroluminescent element, when the content of the charge injection transport material is equal to or greater than the lower limit, film formation tends to occur, and when the content is equal to or less than the upper limit, the composition tends to remain dissolved in the organic solvent.

In the composition for forming an organic electroluminescent device of the present invention, the content of the organic solvent in the total (100% by weight) of the composition for forming an organic electroluminescent device is usually 50% by weight or more, preferably 80% by weight or more, and furthermore It is preferably 90% by weight or more, and usually 99.9% by weight or less, preferably 99.5% by weight or less, and more preferably 99% by weight or less.

When the content of the organic solvent in the total (100% by weight) of the composition for forming an organic electroluminescent element is equal to or greater than the lower limit, the charge injection and transport layer is not precipitated and the dissolved state is easily maintained.

(Other Components Included in Composition for Forming Organic Electroluminescent Element)

The composition for forming an organic electroluminescent element of the present invention may contain other materials as appropriate in addition to the above-described charge injection and transport material, organic solvent, and each surface modifier.

For example, a dopant material contributing to light emission may be included. The content of the dopant material related to light emission is usually 0.05% by weight or more, preferably 0.1% by weight or more, from the viewpoint of efficiently emitting electric charges, and is usually 20% by weight from the viewpoint of avoiding extinction of light emission due to excessive concentration. or less, preferably 10% by weight or less, more preferably 5% by weight or less.

In addition, antioxidants represented by Irganox 1010, butylhydroxyanisole, and the like may be included.

[Organic electroluminescence device]

The organic electroluminescent device of the present invention includes an organic film obtained by drying the composition for forming an organic electroluminescent device of the present invention. The organic electroluminescent element of the present invention preferably has an organic film obtained by applying the composition for forming an organic electroluminescent element of the present invention to a region partitioned by barrier ribs and then drying the composition for forming an organic electroluminescent element.

It is not necessary that all organic films in the organic electroluminescent device are formed using the composition for forming an organic electroluminescent device of the present invention, and which organic film is used for forming an organic electroluminescent device of the present invention. What is necessary is just to form using a composition. Other organic films may be formed using conventionally known materials and methods as appropriate, but in the organic electroluminescent element of the present invention, it is preferable that all organic films to be wet-formed are formed using the composition for forming an organic electroluminescent element of the present invention Do.

The organic electroluminescent element of the present invention preferably has a plurality of regions partitioned off by barrier ribs formed directly on the substrate or through another layer. This area corresponds to a pixel of an organic electroluminescent element.

Fig. 1 shows an example of the general layer structure of the organic electroluminescent device according to the present invention.

1 is a schematic cross-sectional view showing a structural example of an organic electroluminescent device 10 according to the present invention. In FIG. 1, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, and 5 is a A light emitting layer, 6 represents a hole blocking layer, 7 represents an electron transport layer, 8 represents an electron injection layer, and 9 represents a cathode, respectively. In addition, about the partition wall, it is abbreviate|omitted.

The film thickness of the organic film forming each of the above layers is usually about 1 to 1000 nm, but preferably 10 to 500 nm. When the film thickness is equal to or greater than the above lower limit, it is easy to obtain originally required physical properties (charge injection characteristics, transport characteristics, confinement characteristics), and the possibility of occurrence of pixel defects due to foreign substances such as dust is reduced. In addition, when the film thickness is equal to or less than the above upper limit, the electrical resistance of the organic film is suppressed to a low level, and the drive voltage can be reduced.

[Method for producing organic film]

The method for producing an organic film of the present invention includes applying the composition for forming an organic electroluminescent element of the present invention to a region partitioned by barrier ribs, and drying the applied composition for forming an organic electroluminescent element.

The size of the region partitioned by the barrier rib of the present invention is not particularly limited, but it is particularly effective when the long axis: 600 μm or less and the short axis: 300 μm or less. When the opening area is within this range, the ratio of the area where the flatness deteriorates in the vicinity of the partition wall is large, and the effect of the present invention is particularly large.

A conventionally known wet film forming method can be used for coating and drying the composition for forming an organic electroluminescent element. Here, the wet film forming method refers to a composition containing a solvent, spin coating method, dip coating method, die coating method, bar coating method, blade coating method, roll coating method, spray coating method, capillary coating method, ink jet method , screen printing method, gravure printing method, flexographic printing method, and the like. Among these, application|coating using the inkjet method is especially preferable. As for the drying method after application, conventionally known drying methods such as vacuum drying and heat drying may be appropriately used, but vacuum drying is preferable.

(Method of forming bulkhead)

A conventionally well-known formation method may also be used for the formation method of a partition. For example, the method including the application process of apply|coating the photosensitive resin composition for partition formation on a board|substrate, and forming the photosensitive resin composition layer, and the exposure process of exposing the photosensitive resin composition layer is mentioned. As a specific example of the formation method of such a barrier rib, an inkjet method and a photolithography method are mentioned.

As a photosensitive resin composition for forming a partition, the photosensitive resin composition containing (A) ethylenically unsaturated compound, (B) photoinitiator, and (C) alkali-soluble resin is mentioned.

Moreover, the photosensitive resin composition for forming a partition may contain (D) liquid repellent from the viewpoint of forming a liquid-repellent partition, and furthermore, the above-mentioned (A) to (C) components exhibiting an action as a liquid repellent are used. can also Moreover, the photosensitive resin composition for forming a partition contains (E) solvent normally.

(A) component; ethylenically unsaturated compounds

The photosensitive resin composition for forming a partition contains (A) an ethylenically unsaturated compound. (A) It is thought that it becomes highly sensitive by including an ethylenically unsaturated compound.

As used herein, the ethylenically unsaturated compound refers to a compound having one or more ethylenically unsaturated bonds in the molecule, but is capable of widening the difference in polymerizability, crosslinkability, and consequent solubility of the exposed and unexposed areas in the developing solution. In view of the above, it is preferable that the compound has two or more ethylenically unsaturated bonds in the molecule, and the unsaturated bond is derived from a (meth)acryloyloxy group, that is, a (meth)acrylate compound is more preferable. Do.

In particular, it is preferable to use a polyfunctional ethylenic monomer having two or more ethylenically unsaturated bonds in one molecule. The number of ethylenically unsaturated groups of the polyfunctional ethylenic monomer is not particularly limited, but is preferably 2 or more, more preferably 3 or more, even more preferably 5 or more, and more preferably 15 or less, more preferably is less than 10. When it is set to the above lower limit or more, the polymerization property tends to improve and the sensitivity becomes high, and when the value is set to below the above upper limit, the developability tends to be better.

Specific examples of the ethylenically unsaturated compound include esters of aliphatic polyhydroxy compounds and unsaturated carboxylic acids; Esters of aromatic polyhydroxy compounds and unsaturated carboxylic acids; esters obtained by esterification of polyvalent hydroxy compounds such as aliphatic polyhydroxy compounds and aromatic polyhydroxy compounds with unsaturated carboxylic acids and polybasic carboxylic acids; and the like.

Among these, from the viewpoint of appropriate taper angle and sensitivity, it is preferable to use ester (meth)acrylates or urethane (meth)acrylates as (A) ethylenically unsaturated compounds, and dipentaerythritol hexa(meth) Dibasic acid anhydride of acrylate, dipentaerythritol penta(meth)acrylate, 2-trisacryloyloxymethylethylphthalic acid, pentaerythritol tetraacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate It is more preferable to use an adduct, a dibasic acid anhydride adduct of pentaerythritol triacrylate, and the like.

These may be used individually by 1 type, and may use 2 or more types together.

component (B); photopolymerization initiator

The photosensitive resin composition for forming a partition contains (B) a photoinitiator. The photopolymerization initiator is not particularly limited as long as it is a compound that polymerizes the ethylenically unsaturated bond of the ethylenically unsaturated compound (A) with actinic light, and a known photopolymerization initiator can be used.

In the photosensitive resin composition, as the (B) photopolymerization initiator, a photopolymerization initiator commonly used in this field can be used. Examples of such photopolymerization initiators include hexaarylbiimidazole-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, oxime-based photopolymerization initiators, triazine-based photopolymerization initiators, acetophenone-based photopolymerization initiators, benzophenone-based photopolymerization initiators, and hydroxybenzene. photopolymerization initiator, thioxanthone photopolymerization initiator, anthraquinone photopolymerization initiator, ketal photopolymerization initiator, titanocene photopolymerization initiator, halogenated hydrocarbon derivative photopolymerization initiator, organic borate photopolymerization initiator, onium salt photopolymerization initiator, sulfone compound photopolymerization and initiators, carbamic acid derivative photopolymerization initiators, sulfonamide photopolymerization initiators, and triarylmethanol photopolymerization initiators.

These photopolymerization initiators may be contained singly or in combination of two or more thereof in the photosensitive resin composition. Among these photopolymerization initiators, oxime-based photopolymerization initiators and hexaarylbiimidazole compounds are preferred.

Moreover, you may use a chain transfer agent in combination with the said photoinitiator. Examples of the chain transfer agent include compounds containing a mercapto group, carbon tetrachloride, and the like, and since the chain transfer effect tends to be high, it is more preferable to use a compound having a mercapto group. It is considered that bond cleavage easily occurs due to the small S-H bond energy, and hydrogen withdrawal reaction and chain transfer reaction are easily caused. It is effective for sensitivity improvement and surface hardenability.

As the mercapto group-containing compound, 2-mercaptobenzothiazole, 2-mercaptobenzoimidazole, 2-mercaptobenzoxazole, 3-mercapto-1,2,4-triazole, 2-mercapto-4 mercapto group-containing compounds having an aromatic ring such as (3H)-quinazoline, β-mercaptonaphthalene, and 1,4-dimethylmercaptobenzene; Hexanedithiol, Decanedithiol, Butanediolbis(3-mercaptopropionate), Butanediolbisthioglycolate, Ethylene glycolbis(3-mercaptopropionate), Ethylene glycolbisthioglycolate, Trimethylolpropanetris (3-mercaptopropionate), trimethylolpropane trithioglycolate, trishydroxyethyltrithiopropionate, pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tris (3- Mercaptopropionate), butanediolbis (3-mercaptobutyrate), ethylene glycol bis (3-mercaptobutyrate), trimethylolpropanetris (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptobutyrate) butyrate), pentaerythritol tris (3-mercaptobutyrate), 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H,3H and aliphatic mercapto group-containing compounds such as ,5H)-trione.

A variety of these can be used individually by 1 type or in mixture of 2 or more types.

component (C); alkali soluble resin

The photosensitive resin composition for forming a partition contains (C) alkali-soluble resin. The alkali-soluble resin is not particularly limited as long as it can be developed with a developing solution. As the developing solution, an alkali-soluble resin is preferably used. Examples of the alkali-soluble resin include various resins containing a carboxy group or a hydroxyl group. Among them, those having a carboxyl group are preferred, and those having an ethylenically unsaturated group are more preferred, from the viewpoint of obtaining a partition wall with an appropriate taper angle and suppressing outflow due to thermal melting of the partition wall to maintain liquid repellency. Do.

<Carboxyl group-containing (co)polymer (1)>

Representative examples of the carboxyl group-containing (co)polymer include, for example, unsaturated carboxylic acids such as (meth)acrylic acid, crotonic acid, isocrotonic acid, maleic acid, maleic anhydride, itaconic acid, and citraconic acid; Styrene, such as styrene, α-methylstyrene, and hydroxystyrene, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, Hexyl(meth)acrylate, dodecyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, dicyclopentanyl(meth)acrylate, adamantyl(meth)acrylate, isobornyl(meth)acrylate hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, benzyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N - (meth)acrylic acid esters such as (meth)acryloylmorpholine, (meth)acrylonitriles such as (meth)acrylonitrile, (meth)acrylamide, N-methylol (meth)acrylamide, and copolymers with (meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N,N-dimethylaminoethyl(meth)acrylamide, and vinyl compounds such as vinyl acetate.

<Carboxyl group-containing (co)polymer (2)>

In addition, instead of the unsaturated carboxylic acid, a compound obtained by adding a polybasic acid (anhydride) to a hydroxyalkyl (meth)acrylate, and the above styrenes, (meth)acrylic acid esters, (meth)acrylonitriles, (meth) ) copolymers with acrylamides, vinyl compounds and the like.

<Copolymer of unsaturated carboxylic acid and two or more kinds of ethylenically unsaturated group-containing compounds>

As a carboxyl group-containing (co)polymer having an ethylenically unsaturated group in the side chain, for example, allyl (meth) acrylate, 3-allyloxy-2-hydroxypropyl (meth) acrylate, cinnamyl (meth) acrylate, chromium Compounds having two or more types of ethylenically unsaturated groups such as tonyl (meth)acrylate, methallyl (meth)acrylate, N,N-diallyl (meth)acrylamide, or vinyl (meth)acrylate, 1-chlorovinyl (meth) acrylate, 2-phenylvinyl (meth) acrylate, 1-propenyl (meth) acrylate, vinyl crotonate, a compound having two or more ethylenically unsaturated groups such as vinyl (meth) acrylamide; (meth)acrylic acid and other unsaturated carboxylic acids or unsaturated carboxylic acid esters in a proportion of the total amount of the former ethylenically unsaturated group-containing compounds is 10 to 90 mol%, preferably 30 to 80 mol% and copolymers obtained by copolymerizing to a certain degree.

<Epoxy group-containing unsaturated compound-modified carboxyl group-containing (co)polymer>

Further, as a carboxyl group-containing (co)polymer having an ethylenically unsaturated group in the side chain, for example, a carboxyl group-containing (co)polymer is reacted with an epoxy group-containing unsaturated compound to form an epoxy group-containing unsaturated compound on a part of the carboxyl group of the carboxyl group-containing (co)polymer. and modified carboxyl group-containing (co)polymers modified by adding an epoxy group of .

As the carboxyl group-containing (co)polymer, from the viewpoint of sensitivity, (meth)acrylate-(meth)acrylic acid copolymer and styrene-(meth)acrylate-(meth)acrylic acid copolymer of the above-mentioned carboxyl group-containing (co)polymer etc. are preferred.

Further, as the epoxy group-containing unsaturated compound, allyl glycidyl ether, glycidyl (meth) acrylate, α-ethyl glycidyl (meth) acrylate, glycidyl crotonate, glycidyl isocrotonate , aliphatic epoxy group-containing unsaturated compounds such as crotyl glycidyl ether, itaconic acid monoalkyl monoglycidyl ester, fumaric acid monoalkyl monoglycidyl ester, maleic acid monoalkyl monoglycidyl ester, and 3,4-epoxycyclo hexylmethyl (meth)acrylate, 2,3-epoxycyclopentylmethyl (meth)acrylate, 7,8-epoxy [tricyclo[5.2.1.0]decy-2-yl]oxyethyl (meth)acrylate, etc. and unsaturated compounds containing an alicyclic epoxy group.

<Unsaturated carboxylic acid-modified epoxy group and carboxyl group-containing (co)polymer>

Further, as a (co)polymer containing a carboxyl group having an ethylenically unsaturated group in the side chain, for example, an unsaturated carboxylic acid such as (meth)acrylic acid, an aliphatic epoxy group-containing unsaturated compound or an alicyclic epoxy group-containing unsaturated compound, or further unsaturated (meth)acrylic acid, etc. modified epoxy groups and carboxyl group-containing (co)polymers modified by reacting an unsaturated carboxylic acid of and adding a carboxyl group of an unsaturated carboxylic acid to an epoxy group of the copolymer.

<Acid-modified epoxy group-containing copolymer>

Further, as a carboxyl group-containing copolymer having an ethylenically unsaturated group in the side chain, for example, glycidyl (meth)acrylate, α-ethylglycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate 5 to 95 mol% of an epoxy group-containing (meth)acrylate such as 3,4-epoxycyclohexylmethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and (meth)acrylic acid ester A copolymer with usually 5 to 95 mol% of an ethylenically unsaturated compound such as (hereinafter sometimes abbreviated as an epoxy group-containing copolymer) is ethylenic to 10 to 100 mol% of the epoxy groups contained in the copolymer. An acid-modified epoxy group-containing copolymer obtained by adding a polybasic acid (anhydride) to usually 10 to 100 mol% of the hydroxyl groups formed when an unsaturated monocarboxylic acid is added and further added is exemplified.

<Epoxy (meth)acrylate resin (acid-modified epoxy resin)>

As a resin containing a carboxyl group and an ethylenically unsaturated group, for example, an epoxy resin containing a carboxyl group and an ethylenically unsaturated group, in which a polybasic acid (anhydride) is further added to an ethylenically unsaturated group monocarboxylic acid adduct of an epoxy resin, that is, a so-called Epoxy (meth)acrylate resins are exemplified. That is, by ring-opening addition of the carboxy group of ethylenically unsaturated monocarboxylic acid to the epoxy group of the epoxy resin, an ethylenically unsaturated bond is added to the epoxy resin via an ester bond (-COO-), and to the hydroxyl group generated at that time, and those to which one carboxy group of a polybasic acid (anhydride) has been added.

Here, the epoxy resin includes raw material compounds prior to forming the resin by thermal curing, and the epoxy resin can be appropriately selected from known epoxy resins and used. Specifically, for example, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolac epoxy resin, cresol novolak epoxy resin, biphenyl novolak epoxy resin, trisphenol epoxy resin, phenol and dicyclo Polymerization epoxy resin with pentane, dihydroxylfluorene type epoxy resin, dihydroxyalkyleneoxylfluorene type epoxy resin, diglycidyl ether compound of 9,9-bis(4'-hydroxyphenyl)fluorene , diglycidyl etherified product of 1,1-bis(4'-hydroxyphenyl)adamantane, and the like.

In addition, examples of ethylenically unsaturated monocarboxylic acids include (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, etc., and pentaerythritol tri(meth)acrylate succinic anhydride adducts, penta Erythritol tri(meth)acrylate tetrahydrophthalic anhydride adduct, dipentaerythritol penta(meth)acrylate succinic anhydride adduct, dipentaerythritol penta(meth)acrylate phthalic anhydride adduct, dipentaerythritol penta (meth)acrylate tetrahydrophthalic anhydride adducts, reaction products of (meth)acrylic acid and ε-caprolactone, and the like are exemplified.

In addition, as a polybasic acid (anhydride), for example, succinic acid, maleic acid, itaconic acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetra Hydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, Biphenyl tetracarboxylic acid and their anhydrides, etc. are mentioned.

<Modified phenolic resin>

Examples of the resin containing a carboxyl group and an ethylenically unsaturated group include a phenol resin containing a carboxyl group and an ethylenically unsaturated group obtained by adding a polybasic acid (anhydride) to an adduct of an ethylenically unsaturated group-containing epoxy compound of a phenol resin. That is, while an ethylenically unsaturated bond is added to the phenolic resin through an ester bond (-COO-) by ring-opening addition of the epoxy group of the ethylenically unsaturated group-containing epoxy compound to the phenolic hydroxyl group of the phenolic resin, the hydroxyl group generated at that time , those to which one carboxyl group of a polybasic acid (anhydride) has been added.

Here, as a phenolic resin, for example, phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, o-ethylphenol, m-ethylphenol, p -Ethylphenol, propylphenol, n-butylphenol, t-butylphenol, 1-naphthol, 2-naphthol, 4,4'-biphenyldiol, bisphenol-A, pyrocatechol, resorcinol, hydroquinone, pyrolysis At least one of phenols, such as gallol, 1,2,4-benzenetriol, benzoic acid, 4-hydroxyphenylacetic acid, salicylic acid, and phloroglucinol, is catalyzed by an acid, for example, formaldehyde, paraformaldehyde, A novolak resin polycondensed with at least one of aldehydes such as acetaldehyde, paraaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde, and furfural, or ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and a polycondensate thereof Resol resin etc. which were similarly polycondensed except using an alkali catalyst instead of the acid catalyst in polymerization are mentioned. Here, the condensation reaction between phenols and aldehydes is carried out in the absence of a solvent or in a solvent.

<Other alkali-soluble resins>

In addition, in the case of providing a barrier rib to the organic electroluminescent element of the substrate that is easily deteriorated with respect to the alkali developer, in the case of using a developing solution containing a weakly alkaline alkaline compound or a developing solution containing no alkaline compound, As the alkali-soluble resin, 0.1 to 40% by mol, preferably 1 to 30% by mol, of polyvinyl alcohol or the comonomer (preferably, vinyl acetate etc.) mentioned in the carboxyl group-containing (co)polymer (1) is copolymerized vinyl. An alcohol copolymer or a modified polyvinyl alcohol in which 0.1 to 40 mol%, preferably 1 to 30 mol%, of the copolymer exemplified in (1) containing a carboxyl group is introduced by an esterification reaction is preferably used. .

(D) component; liquid repellent

The photosensitive resin composition for forming a partition may contain a liquid repellent. In particular, when an organic electroluminescent element is produced by an inkjet method, it is preferable to contain a liquid repellent, and by containing a liquid repellent, it can impart liquid repellency to the surface of the partition, so that the obtained partition is provided for each pixel of the organic layer. There is a tendency that can be done by preventing color mixing.

Examples of the liquid repellent include silicone-containing compounds and fluorine-based compounds, preferably liquid repellents containing a crosslinking group (hereinafter, sometimes referred to as "liquid repellents containing a crosslinking group"). As a bridge|crosslinking group, an epoxy group or an ethylenically unsaturated group is mentioned, From a viewpoint of suppressing the outflow of the liquid-repellent component of a developing solution, Preferably it is an ethylenically unsaturated group.

In the case of using a liquid repellent containing a crosslinking group, when the formed coating film is exposed to light, the crosslinking reaction on the surface thereof can be accelerated, and the liquid repellent agent is difficult to flow out in the development process, and as a result, the obtained barrier rib has high liquid repellency. It is thought that it can be expressed as

In addition, you may use a polymerization inhibitor, a ultraviolet absorber, surfactant, a thermal polymerization initiator, a coloring agent, and a silane coupling agent suitably.

(E) component; solvent

The photosensitive resin composition for forming the barrier rib usually contains a solvent, and is used in a state in which each of the above-mentioned components is dissolved or dispersed in the solvent (hereinafter, the photosensitive resin composition containing the solvent is described as "photosensitive resin composition solution"). may do). The solvent is not particularly limited, but examples thereof include organic solvents described below.

Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether, propylene glycol-t- Butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, methoxymethyl pentanol, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether, 3-methyl -glycol monoalkyl ethers such as 3-methoxybutanol, 3-methoxy-1-butanol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and tripropylene glycol methyl ether; Glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether ; Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether Acetate, methoxybutyl acetate, 3-methoxybutyl acetate, methoxypentyl acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, dipropylene glycol mono glycol alkyl ether acetates such as methyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, 3-methyl-3-methoxybutyl acetate and 3-methoxy-1-butyl acetate; glycol diacetates such as ethylene glycol diacetate, 1,3-butylene glycol diacetate, and 1,6-hexanol diacetate; alkyl acetates such as cyclohexanol acetate; ethers such as amyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diamyl ether, ethyl isobutyl ether and dihexyl ether; Acetone, methyl ethyl ketone, methyl amyl ketone, methyl isopropyl ketone, methyl isoamyl ketone, diisopropyl ketone, diisobutyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl amyl ketone, methyl butyl ketone, methyl hexyl ketones such as ketones, methyl nonyl ketone, and methoxymethyl pentanone; Monovalent or polyhydric alcohols; aliphatic hydrocarbons such as n-pentane, n-octane, diisobutylene, n-hexane, hexene, isoprene, dipentene, and dodecane; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, methylcyclohexene, and bicyclohexyl; aromatic hydrocarbons such as benzene, toluene, xylene, and cumene; Amyl formate, ethyl formate, ethyl acetate, butyl acetate, propyl acetate, amyl acetate, methyl isobutyrate, ethylene glycol acetate, ethyl propionate, propyl propionate, butyl butyrate, isobutyl butyrate, methyl isobutyrate, ethyl Caprylate, butyl stearate, ethyl benzoate, 3-ethoxymethylpropionate, 3-ethoxyethylpropionate, 3-methoxymethylpropionate, 3-methoxyethylpropionate, 3-methoxypropylpropionate, 3-methoxymethylpropionate chain or cyclic esters such as butyl toxypropionate and γ-butyrolactone; alkoxycarboxylic acids such as 3-methoxypropionic acid and 3-ethoxypropionic acid; halogenated hydrocarbons such as butyl chloride and amyl chloride; ether ketones such as methoxymethylpentanone; nitriles such as acetonitrile and benzonitrile; tetrahydrofurans such as tetrahydrofuran, dimethyltetrahydrofuran, and dimethoxytetrahydrofuran;

In the inkjet method, the photosensitive resin composition whose viscosity is adjusted by dilution with a solvent or the like is used as ink, and ink droplets are ejected onto the substrate by the inkjet method along a predetermined barrier rib pattern to apply the photosensitive resin composition to the substrate. to form a pattern of uncured barrier ribs. Then, the pattern of the non-cured barrier rib is exposed to form a hardened barrier rib on the substrate. The exposure of the uncured barrier rib pattern is performed in the same manner as the exposure step in the photolithography method described later, except that a mask is not used.

In the photolithography method, the photosensitive resin composition layer is formed by applying the photosensitive resin composition to the entire surface of the region where the barrier rib is formed. After the formed photosensitive resin composition layer is exposed according to a predetermined barrier rib pattern, the exposed photosensitive resin composition layer is developed to form barrier ribs on the substrate.

In the coating step of applying the photosensitive resin composition onto the substrate in the photolithography method, a contact transfer type coating device such as a roll coater, reverse coater, bar coater or spinner (rotary coating device) is applied to the substrate on which a barrier rib is to be formed. , A photosensitive resin composition layer is formed by applying the photosensitive resin composition using a non-contact coating device such as a curtain flow coater and, if necessary, removing the solvent by drying such as vacuum drying.

Next, in the exposure process, the photosensitive resin composition layer is irradiated with active energy rays such as ultraviolet rays and excimer laser light using a negative mask, and the photosensitive resin composition layer is partially exposed according to the bank pattern. For exposure, a light source that emits ultraviolet rays such as a high-pressure mercury-vapor lamp, an ultra-high-pressure mercury lamp, a xenon lamp, or a carbon arc lamp can be used. The exposure amount varies depending on the composition of the photosensitive resin composition, but is preferably about 10 to 400 mJ/cm 2 , for example.

Subsequently, in the developing process, the barrier rib is formed by developing the photosensitive resin composition layer exposed to light according to the pattern of the barrier rib with a developing solution. The developing method is not particularly limited, and an immersion method, a spray method, or the like can be used. Specific examples of the developing solution include organic solutions such as dimethylbenzylamine, monoethanolamine, diethanolamine, and triethanolamine, and aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, and quaternary ammonium salts. Further, an antifoaming agent or a surfactant may be added to the developing solution.

After that, post-baking is applied to the barrier rib after development to heat-harden it. Post-baking is preferably performed at 150 to 250° C. for 15 to 60 minutes.

Example

Hereinafter, the present invention will be described more specifically by showing examples. However, the present invention is not limited to the following examples, and the present invention can be implemented with arbitrary changes without departing from the gist thereof.

(Example 1)

<Preparation of composition for organic electroluminescent device>

A first surface modifier, a third surface modifier, a fifth surface modifier, or a seventh surface modifier in organic solvent 1 in which butyl benzoate, diphenyl ether, and 2-phenoxyethyl acetate are mixed in a weight ratio of 50:49:1 (Hereinafter, in the examples, these are collectively referred to as "surface modifier A") KF-96 10cs (manufactured by Shin-Etsu Chemical Co., Ltd.) at 100 ppm by weight (i.e., the weight of organic solvent 1 is 100 parts by weight, 0.01 10 cs of KF-96 by weight was used), the second surface modifier, the fourth surface modifier, the sixth surface modifier, or the eighth surface modifier (hereinafter, in the examples, they are collectively referred to as "surface modifier B") As a solution, a mixture of 500 ppm by weight of SP-O30V (manufactured by Kao Corporation) (ie, 0.05 part by weight of SP-O30V was used with the weight of organic solvent 1 as 100 parts by weight) was prepared.

Subsequently, polymers (P-1) and (P-2) having a weight average molecular weight of 40,000 having an aromatic amine derivative as a unit skeleton, which is a charge injection transport material, and an electron-accepting compound (A-1) at a weight ratio of 75:25:20 Composition 1 for forming an organic electroluminescent element was prepared by mixing 100 parts by weight of the organic solvent 1 and dissolving the mixture to 1.0 parts by weight in the previously prepared solution.

In the composition 1 for forming an organic electroluminescent element, the surface tension was measured by the method described above, and the surface tension of the organic solvent 1 alone, that is, Sa was 36.0 (mN/m), and only the surface modifier A in the organic solvent 1 was found. The surface tension when 100 ppm by weight was dissolved, that is, S1x and S1y, was 29.0 (mN/m), and the surface tension when only 100 ppm by weight of the surface modifier B was dissolved in organic solvent 1, that is, S2y, was 36.4 (mN/m). , The surface tension when only 1000 ppm by weight of the surface modifier B was dissolved in organic solvent 1 was 35.6 (mN/m). From these values, it is estimated that the surface tension, ie, S2x, when only 500 ppm by weight of the surface modifier B is dissolved in organic solvent 1 is in the range of 35.6 to 36.4 (mN/m). From these values, it can be seen that the composition 1 for forming an organic electroluminescent element satisfies the above formulas (1) to (4).

In addition, the surface tension of pure water, that is, Sa', is 72.7 (mN/m), and the surface tension when only 1000 ppm by weight of the first surface modifier is dissolved in pure water, that is, S1z, is 61.0 (mN/m), and the first surface modifier in pure water is 61.0 (mN/m). 2 The surface tension when only 1000 ppm by weight of the surface modifier was dissolved, that is, S2z, was 32.5 (mN/m), and it was found that the composition 1 for forming an organic electroluminescent device satisfies the above formula (5).

<Formation of Organic Film into Partition Wall>

In FIG. 2, the mode of formation of the organic film in the partition wall of this form is shown as a schematic diagram.

Using acrylic resin 1 having liquid repellency on an ITO substrate 20, a rectangle with rounded corners (major axis length (indicated by b in FIG. 2); 0.3 mm, minor axis length (in FIG. 2 by a) A barrier rib having a thickness of 1.7 μm was formed by the above-described photolithography forming method so as to have a 0.1 mm)-shaped opening (corresponding to “a region partitioned by barrier ribs”). The pitch of each opening was 0.2 mm pitch in the minor axis direction (indicated by c in FIG. 2) and 0.5 mm pitch in the major axis direction (indicated by d in FIG. 2). Subsequently, composition 1 for forming an organic electroluminescent element was applied to desired openings of the ITO substrate on which the barrier ribs were formed using an inkjet printer (DMP-2831 manufactured by Fujifilm Corporation) to a dry film thickness of about 30 nm. Thereafter, the organic solvent was removed by vacuum drying, and the composition 1 for forming an organic electroluminescent element was dried, fired at 230° C. for 30 minutes, an organic film was formed, and openings 12 formed with the organic film were formed.

In Example 1, as shown in FIG. 2, openings 13 with no organic film formed thereon were provided at intervals of 5 rows in the direction of the minor axis of the openings.

<<Measurement of the flatness of the organic film in the barrier rib>>

The film thickness of the organic film was measured for the ITO substrate on which the organic film was formed using a stylus-type surface roughness meter (P15 manufactured by Tencor Co., Ltd.). The stylus scan of the surface roughness meter was performed in such a way that the openings in which the barrier rib, the organic film were formed, and the openings in which the organic film was not formed were sequentially scanned between A and B in FIG. 2 . That is, the scanning direction was the short axis direction, and the measurement was performed so as to cross the center of the opening in the long axis direction, and sandwich the opening formed with the organic film between the openings without forming the organic film. Next, the profile data between A and B obtained by measurement is leveled based on the data of the region where the organic film is not formed at both ends, the slope of the profile data is corrected, and the organic film is formed for the region where the organic film is not formed. The height of the region was regarded as the film thickness of the organic film.

Next, within the scanned openings, after averaging the profile data of the openings formed with the two organic films in the center, the average film thickness Da of the area of 4 μm in the center of the openings of the organic film is calculated, and the area where the difference from Da exceeds 5 nm The width X μm of the opening was calculated. Then, the ratio of the region where the difference from Da in the width Y μm of the opening was 5 nm or less, that is, the value of (Y−X)/Y (%), was taken as flatness. The width Y of the opening was calculated from the profile data of the opening where no organic film was formed. It means that the uniformity of the film thickness of the organic film in an opening part is so good that the value of flatness is large.

The flatness of the organic film comprising the composition 1 for forming an organic electroluminescent device of Example 1 was 82%.

(Example 2)

In the preparation of composition 1 for forming an organic electroluminescent element of Example 1, as the surface modifier B, instead of SP-O30V (manufactured by Kao Corp.), Emulgen A500 (manufactured by Kao Corp.) was used, except for preparing (the same as in Example 2). The organic electroluminescent element-forming composition was referred to as “organic electroluminescent element-forming composition 2”), an organic film was prepared in the same manner as in Example 1, and flatness was measured.

In the composition 2 for forming an organic electroluminescent element, the surface tension was measured by the method described above. ), the surface tension when only 1000 ppm by weight of the surface modifier B was dissolved in organic solvent 1 was 36.0 (mN/m). From these values, it is estimated that the surface tension, that is, S2x, when only 500 ppm by weight of the surface modifier B is dissolved in organic solvent 1 is in the range of 36.0 to 36.2 (mN/m). From these values, it is understood that the composition 2 for forming an organic electroluminescent element satisfies the above formulas (1) to (4).

In addition, it was found that the surface tension, that is, S2z, when only 1000 ppm by weight of the surface modifier B was dissolved in pure water was 45.6 (mN/m), and the composition 2 for forming an organic electroluminescent device satisfies the above formula (5). can

The flatness of the organic film comprising the composition 2 for forming an organic electroluminescent device of Example 2 was 82%.

(Comparative Example 1)

In the preparation of composition 1 for forming an organic electroluminescent device of Example 1, an organic film was formed in the same manner as in Example 1, except that only 10 cs of KF-96 by weight was mixed with 10 cs of surface modifier without using SP-O30V. degree was measured.

The flatness of the organic film of Comparative Example 1 was 64%.

Table 1 shows the results of Examples 1 and 2 and Comparative Example 1.

(Example 3)

<Preparation of composition for organic electroluminescent device>

A solution was prepared by mixing isoamyl benzoate with 100 ppm by weight of KF-96 10cs (manufactured by Shin-Etsu Chemical Co., Ltd.) as the surface modifier A and 500 ppm by weight of SP-O30V (manufactured by Kao Corporation) as the surface modifier B. Next, a polymer (P-3) having a weight average molecular weight of 40,000 and having an aromatic amine derivative as a unit skeleton, which is a charge injection and transport material, is dissolved in a previously prepared solution to have a solid content concentration of 1.0% by weight. Composition 3 for Forming an Organic Electroluminescent Device prepared

In this Example 3, the surface tension was measured by the above-described method, and the surface tension of isoamyl benzoate alone, that is, Sa was 31.5 (mN/m), and 100 weight of only the surface modifier A was added to isoamyl benzoate. The surface tension when dissolved in ppm, that is, S1x and S1y, was 29.4 (mN/m), and the surface tension when only 100 ppm by weight of the surface modifier B was dissolved in isoamyl benzoate, that is, S2y, was 32.0 (mN/m), The surface tension when only 1000 ppm by weight of the surface modifier B was dissolved in isoamyl benzoate was 32.0 (mN/m). From these values, it is estimated that the surface tension, that is, S2x, when only 500 ppm by weight of the surface modifier B is dissolved in isoamyl benzoate is also 32.0 (mN/m). From these values, it is understood that the composition 3 for forming an organic electroluminescent element satisfies the above formulas (1) to (4).

In addition, it was found that the surface tension, that is, S2z, when only 1000 ppm by weight of the surface modifier B was dissolved in pure water was 32.5 (mN/m), and the composition 3 for forming an organic electroluminescent device satisfies the above formula (5). can

<Formation of two-layer film of organic film into barrier rib>

An organic film pattern 1 having an organic film containing composition 1 for forming an organic electroluminescent element was formed in the same manner as in Example 1, except that the openings where no organic film was formed were provided at intervals of 7 rows in the minor axis direction of the openings. .

Next, with respect to the organic film pattern 1, in addition to the rows of openings in which the organic film containing the composition 1 for forming an organic electroluminescent element is not formed, a pattern in which an organic film is not formed even in one row on both sides of the pattern is applied to desired openings. Then, using an inkjet printer (DMP-2831 manufactured by Fujifilm Corporation), the composition 3 for forming an organic electroluminescent element was applied to a dry film thickness of about 20 nm. Thereafter, the organic solvent is removed by vacuum drying, the composition 3 for forming an organic electroluminescent element is dried, and the organic film is formed by baking at 230° C. for 30 minutes, and the organic film containing the composition 1 for forming an organic electroluminescent element is formed. And an organic layer pattern 2 having an organic layer including the composition 3 for forming an organic electroluminescent device was formed.

<<Measurement of the flatness of the organic film in the barrier rib>>

As in Example 1, the film thickness of the organic film was measured for the ITO substrate on which the organic film was formed using a stylus-type surface roughness meter (P15 manufactured by Tencor Co., Ltd.). Here, in order to evaluate the flatness of the organic film containing the organic electroluminescent element-forming composition 3 on the upper layer side of the stacked organic films, for the film thickness of the organic film containing the organic electroluminescent element-forming composition 1, the organic film An average film thickness profile 1 of a region where only the organic film containing the composition 1 for forming an organic electroluminescent element was formed was calculated based on the openings not formed. Next, based on the region where only the organic film containing the composition 1 for forming an organic electroluminescent element is formed, an organic film containing the composition 1 for forming an organic electroluminescent element and a composition 3 for forming an organic electroluminescent element are formed. The average film thickness profile 2 of the region where the organic film was formed was calculated and the average film thickness profile of only the organic film containing the composition 3 for forming an organic electroluminescent element was calculated by subtracting the average film thickness profile 1 described above. By calculating the flatness from this profile data, it becomes possible to evaluate the flatness of the organic film alone containing the organic electroluminescent element-forming composition 3 as an upper layer in the laminated film.

The flatness of the organic film comprising the composition 3 for forming an organic electroluminescent device of Example 3 was 89%.

(Comparative Example 2)

In preparing the composition 3 for forming an organic electroluminescent device of Example 3, an organic film was formed in the same manner as in Example 3, except that SP-O30V was not used and only 10 cs of KF-96 by weight was mixed, The flatness of the upper organic film in the laminated film was measured.

The flatness of the upper organic film in the multilayer film of Comparative Example 2 was 67%.

(Comparative Example 3)

In Comparative Example 2, an organic film was formed in the same manner as in Comparative Example 2, except that the content of the surface modifier KF-96 10cs was changed to 100 ppm by weight, and the flatness of the upper organic film in the laminated film was measured.

The flatness of the upper organic film in the multilayer film of Comparative Example 3 was 76%.

(Comparative Example 4)

In preparing the composition 3 for forming an organic electroluminescent element of Example 3, the surface modifier KF-96 10cs was mixed with 10 ppm by weight and SP-O30V (manufactured by Kao Corp.) was mixed with 500 ppm by weight, in the same manner as in Example 3. An organic film was formed, and the flatness of the upper organic film in the laminated film was measured.

The flatness of the upper organic film in the laminated film of Comparative Example 4 was 65%.

Table 2 shows the results of Example 3, Comparative Example 2, Comparative Example 3 and Comparative Example 4.

(Example 4)

<Preparation of composition for organic electroluminescent device>

A composition 4 for forming an organic electroluminescent element was prepared in the same manner as in the composition 3 for forming an organic electroluminescent element described in Example 3, except that organic solvent 1 was used instead of isoamyl benzoate.

Subsequently, a solution was prepared by mixing 100 ppm by weight of KF-96 10cs (manufactured by Shin-Etsu Chemical Co., Ltd.) as the surface modifier A and 500 ppm by weight of SP-O30V (manufactured by Kao Corporation) as the surface modifier B in the organic solvent 1. Next, compounds (H-1) and (H-2), which are charge injection and transport materials, and (D-1), which is a light emitting material, are mixed in a weight ratio of 30:70:20, and the solid content concentration is added to the previously prepared solution. It dissolved so that it might become 2.4 weight%, and the composition 5 for organic electroluminescent element formation was produced.

Since the composition 5 for forming an organic electroluminescent device described above is the same as the composition 1 for forming an organic electroluminescent device with respect to the organic solvent and the surface modifier, it satisfies the above formulas (1) to (4) and the above formula (5). can know that

<Formation of three-layer film of organic film into barrier rib>

In the same manner as in Example 3, an organic film pattern 1 was formed.

Subsequently, the composition for forming an organic electroluminescent element was formed in the organic film pattern 1 by using an inkjet printer (DMP-2831 manufactured by Fujifilm Co., Ltd.) with respect to the opening where the organic film containing the composition 1 was formed. 4 was applied to a dry film thickness of about 20 nm. Thereafter, the organic solvent is removed by vacuum drying, the composition 4 for forming an organic electroluminescent element is dried, and the composition 4 is baked at 230° C. for 30 minutes to form an organic film, and the organic film containing the composition 1 for forming an organic electroluminescent element is formed. And an organic layer pattern 3 having an organic layer including the composition 4 for forming an organic electroluminescent device was formed.

Then, with respect to the organic film pattern 3, desired openings are printed so that in addition to the rows of openings on which organic films are not formed, even one row on both sides of the pattern is formed, an inkjet printer (DMP-2831 manufactured by Fujifilm Corporation) is used. was used to apply the composition 5 for forming an organic electroluminescent element to a dry film thickness of about 60 nm. Thereafter, the organic solvent is removed by vacuum drying, and the composition 5 for forming an organic electroluminescent element is dried, fired at 120° C. for 20 minutes, and an organic film containing the composition 1 for forming an organic electroluminescent element, an organic electroluminescent element An organic film pattern 4 having an organic film containing the forming composition 4 and an organic film containing the composition 5 for forming an organic electroluminescent device was formed.

<<Measurement of the flatness of the organic film in the barrier rib>>

As in Example 1, the film thickness of the organic film was measured for the ITO substrate on which the organic film was formed using a stylus-type surface roughness meter (P15 manufactured by Tencor Co., Ltd.). Here, in order to evaluate the flatness of the organic film containing the organic electroluminescent element-forming composition 5 of the uppermost layer of the stacked organic films, the organic electroluminescent element-forming organic film containing the organic electroluminescent element-forming composition 1 Regarding the film thickness of the laminated film in which the organic film containing the composition 4 is stacked, the composition 4 for forming an organic electroluminescent element is applied on the organic film containing the composition 1 for forming an organic electroluminescent element based on the openings in which the organic film is not formed. The average film thickness profile 1' of the laminated film in which the containing organic film is stacked is calculated. Then, based on the region where only the laminated film in which the organic film containing the composition 4 for forming an organic electroluminescent element is stacked on the organic film containing the composition 1 for forming an organic electroluminescent element is formed, Average film thickness profile 2 of a laminated film in which an organic film containing the composition 4 for forming an organic electroluminescent element is laminated on an organic film containing the composition 1 and an organic film containing the composition 5 for forming an organic electroluminescent element are formed ' was calculated, and the average film thickness profile of only the organic film containing the composition 5 for forming an organic electroluminescent element was calculated by subtracting the above-described average film thickness profile 1'. By calculating the flatness from this profile data, the flatness of the organic film alone containing the composition 5 for forming an organic electroluminescent element as the uppermost layer in the three-layer film can be evaluated.

The flatness of the organic film comprising the composition 5 for forming an organic electroluminescent device of Example 4 was 68%.

(Comparative Example 5)

In preparing the composition 5 for forming an organic electroluminescent element of Example 4, an organic film was formed in the same manner as in Example 4, except that SP-O30V was not used and only 10 cs of KF-96 by weight was mixed, The flatness of the uppermost organic film in the three-layer film was measured.

The flatness of the uppermost organic film in the three-layer film of Comparative Example 5 was 55%.

The results of Example 4 and Comparative Example 5 are shown in Table 3.

(Example 5)

On an ITO substrate, resin 2 having liquid repellency, which is different from acrylic resin 1 used in Example 1, was used, and a rectangle with rounded corners (long axis length (indicated by b in FIG. 2); about 0.28 mm , minor axis length (indicated by a in Fig. 2); about 0.078 mm) shaped opening (corresponding to the "region partitioned by barrier ribs") with a thickness of 1.5 μm by the above-described formation method by photolithography. formed a bulkhead. The pitch of each opening was about 0.135 mm pitch in the minor axis direction (indicated by c in FIG. 2 ) and about 0.370 mm pitch in the major axis direction (indicated by d in FIG. 2 ). An organic film was formed in the same manner as in Example 1, except that the ITO substrate on which the barrier ribs were formed was used, and flatness was measured.

The flatness of the organic film comprising the composition 1 for forming an organic electroluminescent device of Example 5 was 83%.

(Example 6)

In the same manner as in Composition 1 for Forming an Organic Electroluminescent Device described in Example 1, except that 100 ppm by weight of F-552 (manufactured by DIC Corporation) was used as the surface modifier A and 500 ppm by weight of SP-O30V (manufactured by Kao Corporation) was used as the surface modifier B. Thus, a composition 6 for forming an organic electroluminescent element was prepared.

In the composition 6 for forming an organic electroluminescent element, the surface tension was measured by the method described above. /m) was. From this and the above-described values, it is understood that the composition 6 for forming an organic electroluminescent element satisfies the above formulas (1) to (4).

In Example 5, an organic film was formed in the same manner as in Example 5, except that the composition 6 for forming an organic electroluminescent element was used, and flatness was measured.

The flatness of the organic film comprising the composition 6 for forming an organic electroluminescent device of Example 6 was 84%.

(Example 7)

In Example 6, except that composition 7 for forming an organic electroluminescent element in which 300 ppm by weight of SP-O30V (manufactured by Kao Corp.) and 200 ppm by weight of Emulgen A60 (manufactured by Kao Corp.) were mixed as the surface modifier B was used. An organic film was formed in the same manner as in 6, and flatness was measured.

In the composition for forming an organic electroluminescent element 7, the surface tension was measured by the method described above. The surface tension when 300 ppm by weight of SP-O30V and 200 ppm by weight of Emulgen A60 were dissolved in the organic solvent 1, that is, S2x was 35.4 (mN/m). From this and the above-described values, it can be seen that the composition 7 for forming an organic electroluminescent element satisfies the above formulas (1) to (4).

The flatness of the organic film comprising the composition 7 for forming an organic electroluminescent device of Example 7 was 84%.

(Comparative Example 6)

In Example 5, an organic film was formed in the same manner as in Example 5, except that a composition for forming an organic electroluminescent element was prepared without adding a surface modifier, and flatness was measured.

The flatness of the organic film of Comparative Example 6 was 71%.

(Comparative Example 7)

In Example 5, an organic film was formed in the same manner as in Example 5 except that a composition for forming an organic electroluminescent element was prepared and used in which only 10 cs of KF-96 was mixed with 100 ppm by weight of the surface modifier without using SP-O30V. , the flatness was measured.

The flatness of the organic film of Comparative Example 7 was 42%.

(Comparative Example 8)

In Example 5, an organic film was formed in the same manner as in Example 5 except that a composition for forming an organic electroluminescent element was prepared and used in which only 500 ppm by weight of SP-O30V was mixed without using KF-96 10cs. , the flatness was measured.

The flatness of the organic film of Comparative Example 8 was 63%.

(Comparative Example 9)

In Example 6, an organic film was formed in the same manner as in Example 6 except that a composition for forming an organic electroluminescent element was prepared and used in which only 100 ppm by weight of the surface modifier F-552 was mixed without using SP-O30V. Flatness was measured.

The flatness of the organic film of Comparative Example 9 was 71%.

Table 4 shows the results of Examples 5 to 7 and Comparative Examples 6 to 9.

Tables 5 to 7 summarize the surface tension measurement results of Examples. In addition, in Table 6, the numerical range expressed using "to" means the range which includes the numerical value described before and after "to" as a lower limit and an upper limit.

From Example 1 and Comparative Example 1, it can be seen that the flatness of the organic film is improved from 64% to 82% by incorporating the predetermined surface modifier B into the composition for forming an organic electroluminescent device containing only the surface modifier A. . In Example 2, a surface modifier B different from that in Example 1 was contained, but a flatness of 82% was similarly obtained, and it was found that the effect of the present invention was obtained regardless of the material of the surface modifier.

Further, in Example 3 and Comparative Examples 2 to 4, an organic solvent and a charge injection transport material different from those of Examples 1 and 2 were used in the composition for forming an organic electroluminescent element, but the surface modifier B was not contained. It can be seen that the flatness of the organic film is improved from 65 to 76% to 89% compared to the cases (Comparative Examples 2 and 3) and the case where the predetermined surface tension value is not satisfied (Comparative Example 4). In the case of Example 4 and Comparative Example 5 as well, it can be seen that the flatness is improved from 55% to 68%.

Further, in Example 5 and Comparative Examples 6 to 8, a case where a barrier rib material different from the above example is used is shown, but when the composition for forming an organic electroluminescent element does not contain a surface modifier (Comparative Example 6), 1 Compared to the case where only a kind of surface modifier was contained (Comparative Examples 7 and 8), it was found that the flatness was clearly improved.

In Example 6, a surface modifier A different from that in Example 5 is contained, but similarly, when no surface modifier is contained (Comparative Example 6), when only one type of surface modifier is contained (Comparative Examples 8 and 9 ), the flatness is improved from 63 to 71% to 84%, and it can be seen that the effect of the present invention is obtained regardless of the material of the surface modifier.

Further, in Example 7, in addition to the surface modifier used in Example 6, another surface modifier B is contained, but similarly, when no surface modifier is contained (Comparative Example 6), only one type of surface modifier is used. It can be seen that the flatness is improved from 71% to 84% compared to the case where it is contained (Comparative Example 9).

In addition to materials for organic devices such as organic electroluminescent elements, the present invention has characteristics as various fields in which organic electroluminescent elements are used, such as flat panel displays (eg, for OA computers and wall-mounted televisions) and surface light emitting bodies. It can be suitably used in the field of light sources (for example, light sources for photocopiers, backlight sources for liquid crystal displays and instruments), display boards, signs, lighting devices, and the like.

1: Substrate
2: anode
3: hole injection layer
4: hole transport layer
5: light emitting layer
6: hole blocking layer
7: electron transport layer
8: electron injection layer
9: cathode
10: organic electroluminescent element
11: bulkhead
12: opening formed with an organic film
13: openings that do not form an organic film
20: Substrate

Claims (14)

A composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, at least one first surface modifier and at least one second surface modifier,
The surface tension (unit: mN/m) of the organic solvent is Sa, the total content of the one or more first surface modifiers with respect to 100 parts by weight of the organic solvent is C1 parts by weight, and 100 parts by weight of the organic solvent The content of the total of the one or more types of second surface modifiers for C2 parts by weight,
The first surface modifier may be polysiloxane; compounds obtained by partially ether-modified, ester-modified, or aralkyl-modified polysiloxanes; Compounds in which the methyl group of polysiloxane is substituted with an alkyl group; or a reactive polysiloxane obtained by adding a reactive group to polysiloxane;
The second surface modifier is polyoxyalkylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene alkylamine, polyoxyethylene cumyl fuel ether, sorbitol fatty acid esters, sorbitan fatty acid esters, glycerin fatty acid esters, sucrose fatty acid esters, sucrose derivatives or fatty acid esters,
Each of the first surface modifiers satisfies the following formula (1) when S1y is the surface tension (unit: mN/m) of a mixture in which 0.01 part by weight of the first surface modifier is dissolved in 100 parts by weight of the organic solvent. It is a surface modifier to
Sa-S1y>1.0 … (One)
Each of the second surface modifiers satisfies the following formula (2) when S2y is the surface tension (unit: mN/m) of a mixture in which 0.01 part by weight of the second surface modifier is dissolved in 100 parts by weight of the organic solvent. It is a surface modifier to
Sa-S2y≤1.0 … (2)
When the surface tension (unit: mN/m) of a mixture of 100 parts by weight of the organic solvent and the C1 part by weight of the first surface modifier is S1x, the following formula (3) is satisfied,
Sa-S1x>1.0 … (3)
When S2x is the surface tension (unit: mN/m) of a mixture of 100 parts by weight of the organic solvent and the C2 part by weight of the second surface modifier, the following equation (4) is satisfied,
Sa-S2x<1.0 … (4)
A composition for forming an organic electroluminescent device. The composition for forming an organic electroluminescent device according to claim 1, wherein C1 is 0.001 to 1. The composition for forming an organic electroluminescent device according to claim 1, wherein C2 is 0.001 to 1. delete delete delete A composition for forming an organic electroluminescent device containing at least a charge injection and transport material, an organic solvent, a fifth surface modifier and a sixth surface modifier,
The fifth surface modifier is polysiloxane; compounds obtained by partially ether-modified, ester-modified, or aralkyl-modified polysiloxanes; Compounds in which the methyl group of polysiloxane is substituted with an alkyl group; or a reactive polysiloxane obtained by adding a reactive group to polysiloxane;
The sixth surface modifier is polyoxyalkylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene alkylamine, polyoxyethylene cumyl fuel ether, sorbitol fatty acid esters, sorbitan fatty acid esters, glycerin fatty acid esters, sucrose fatty acid esters, sucrose derivatives or fatty acid esters,
The surface tension of pure water (unit: mN/m) is Sa', and the surface tension of a mixture of 100 parts by weight of pure water and 0.1 part by weight of the fifth surface modifier (unit: mN/m) is S1z, When S2z is the surface tension (unit: mN/m) of a mixture of 100 parts by weight of pure water and 0.1 part by weight of the sixth surface modifier, the following equation (5) is satisfied,
Sa'>S1z>S2z . . . (5)
A composition for forming an organic electroluminescent device. The composition for forming an organic electroluminescent device according to claim 7, wherein the content of the fifth surface modifier is 0.001 to 1 part by weight based on 100 parts by weight of the organic solvent. The composition for forming an organic electroluminescent device according to claim 7, wherein the content of the sixth surface modifier is 0.001 to 1 part by weight based on 100 parts by weight of the organic solvent. delete delete delete An organic electroluminescent element comprising an organic film obtained by drying the composition for forming an organic electroluminescent element according to any one of claims 1 to 3 and 7 to 9. Application of the composition for forming an organic electroluminescent device according to any one of claims 1 to 3 and 7 to 9 to a region partitioned by barrier ribs, and the applied composition for forming an organic electroluminescent device A method for producing an organic film comprising drying.

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