JP2010103105A - Method for manufacturing organic field light-emitting element, organic field light-emitting element, organic el display, and organic el illumination - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an organic field light-emitting element which has low drive voltage when forming a bank on an organic layer and has long lifetime, and an organic field light-emitting element which has low drive voltage and long lifetime. <P>SOLUTION: In the method for manufacturing an organic field light-emitting element having a first electrode, a second electrode formed to face to the first electrode, a first organic layer between the first electrode and the second electrode, a bank formed on the first organic layer at a pattern shape, and a second organic layer formed at an area divided by the bank, the manufacturing method includes a developing process and a heating process in a process of forming the bank, wherein a process of cleaning by a polarized organic solvent is included between the developing process and the heating process and/or the developing process is prepared in the process of forming the bank. The developing process develops by developing fluid including an alkaline compound, the polarized organic solvent, and water. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing an organic electroluminescent element having a bank, an organic EL display using the organic electroluminescent element, and organic EL illumination.

In recent years, an electroluminescent element (organic electroluminescent element) using an organic thin film has been developed. An organic electroluminescent element is usually provided by laminating a plurality of organic layers (light emitting layer, hole injection layer, hole transport layer, electron transport layer, etc.) between an anode and a cathode. Examples of the method for forming the organic layer in the organic electroluminescence device include a vacuum deposition method and a wet film formation method.
Among these, since the vacuum deposition method is easy to stack, it has the advantage that the charge injection from the anode and / or the cathode is improved and the exciton light-emitting layer is easily contained.

On the other hand, the wet film formation method does not require a vacuum process, is easy to increase in area, and is easy to mix a plurality of materials having various functions into one layer (composition). There is.
Further, Patent Document 1 discloses an organic electroluminescent element in which a bank is provided on an anode for the purpose of separating and arranging cathode wirings formed on an organic layer. However, in an organic electroluminescent device having a bank on the anode, the film thickness of the organic layer provided in the region partitioned by the bank becomes non-uniform, and display unevenness may occur when a display is manufactured. It was.

  In order to solve this non-uniform film thickness, Patent Documents 2 and 3 disclose a technique for forming a bank on an organic layer.

JP 2001-351777 A JP 2004-234901 A JP 2004-235128 A

However, the organic electroluminescent element having a bank on the organic layer has a problem that the driving voltage is high and the driving life is shortened.
An object of the present invention is to provide a method for manufacturing an organic electroluminescence device having a low driving voltage and a long driving life even when a bank is formed on an organic layer.
Another object of the present invention is to provide an organic electroluminescence device having a low driving voltage and a long driving life.

As a result of intensive studies by the present inventors, a residue of a bank forming composition existing in a region (bank opening) defined by a bank formed on an organic layer (hereinafter simply referred to as “residue of a bank forming composition”). It was found that this is one of the factors that increase the drive voltage and shorten the service life.
Furthermore, the inventors have a development step and a heating step in the step of forming the bank, and include a step of washing with a polar organic solvent between the development step and the heating step, and / or There is a development step in the step of forming a bank, and in the development step, development with a developer containing an alkaline compound, a polar organic solvent and water reduces the residue of the bank forming composition, and the above problem The present invention has been found.

  That is, the first of the present invention has a first electrode and a second electrode formed so as to face the first electrode, and between the first electrode and the second electrode, Method for manufacturing an organic electroluminescent device comprising: a first organic layer, a bank formed in a pattern on the first organic layer, and a second organic layer formed in a region partitioned by the bank In the organic electroluminescent device, the method includes a development step and a heating step in the step of forming the bank, and a step of washing with a polar organic solvent between the development step and the heating step. Lies in the manufacturing method.

  The second of the present invention has a first electrode and a second electrode formed so as to face the first electrode, and between the first electrode and the second electrode, Method for manufacturing an organic electroluminescent device comprising: a first organic layer, a bank formed in a pattern on the first organic layer, and a second organic layer formed in a region partitioned by the bank In the organic electroluminescent device, the method includes a development step in the step of forming the bank, and the development step is performed using a developer containing an alkaline compound, a polar organic solvent, and water. Lies in the manufacturing method.

  Furthermore, the present invention provides an organic electroluminescent device manufactured by any one of the above-described organic electroluminescent device manufacturing methods, an organic EL display using the organic electroluminescent device, and It exists in organic EL lighting.

  In an organic electroluminescence device having a bank on an organic layer, an organic electroluminescence device having little emission unevenness and defects, a low driving voltage, and a long driving life can be manufactured.

It is sectional drawing which shows typically an example of the structure of the organic electroluminescent element of this invention. It is sectional drawing which shows typically another example of the structure of the organic electroluminescent element of this invention. It is sectional drawing which shows typically another example of the structure of the organic electroluminescent element of this invention. It is sectional drawing which shows typically another example of the structure of the organic electroluminescent element of this invention.

Below, the manufacturing method of the organic electroluminescent element of this invention, an organic electroluminescent element, an organic electroluminescent display, and the embodiment of organic electroluminescent illumination are demonstrated in detail, The description about the following structural requirements is embodiment of this invention. The present invention is not specified by these contents unless it exceeds the gist.
The organic electroluminescent element of the present invention has a first electrode and a second electrode formed so as to face the first electrode, and between the first electrode and the second electrode, An organic electroluminescence device having a first organic layer, a bank formed in a pattern on the first organic layer, and a second organic layer formed in a region partitioned by the bank.

The first organic layer and the second organic layer may be any layers as long as they are provided between the first electrode and the second electrode of the organic electroluminescent element. Is preferably a hole injection layer or a hole transport layer, and the second organic layer is preferably a light emitting layer.
In the present invention, it is sufficient that the first organic layer and the second organic layer are formed adjacent to each other, and the first organic layer and the second organic layer are interposed between the first electrode and the second electrode. Other layers may be formed in addition to the two organic layers.

The method for forming these organic layers and banks will be described in detail below, but the present invention is not limited thereto.
<Method for producing organic electroluminescent element>
Hereinafter, after forming the first electrode on the substrate with the first electrode as the anode and the second electrode as the cathode, a hole injection layer is formed, and the first organic layer is formed on the hole injection layer. A case where a light-emitting layer is formed as the hole transport layer and the second organic layer, and an electron transport layer and an electron injection layer are formed on the light-emitting layer will be described as an example. This example is a suitable example as an application example of the method for producing an organic electroluminescent element of the present invention, but the present invention is not limited to this example.

In FIG. 2, the schematic diagram showing the cross section of the organic electroluminescent element of this example is shown. In FIG. 2, 1 is a substrate, 2 is an anode (first electrode), 3 is a hole injection layer, 4 is a hole transport layer (first organic layer), 5 is a bank, and 6 is a light emitting layer (second electrode). Organic layer), 8 represents an electron injection layer, 9 represents an electron transport layer, and 7 represents a cathode (second electrode).
In the present invention, the wet film forming method includes, for example, 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, nozzle printing. This method is a wet film formation method such as a method, a screen printing method, an offset printing method, a gravure printing method, a flexographic printing method, an aerosol method, or an aerosol jet method. Among these film forming methods, a spin coating method, a spray coating method, and an ink jet method are preferable. This is because the liquid property specific to the coating composition used for the organic electroluminescent element is matched.

(substrate)
The substrate serves as a support for the organic electroluminescence device, and quartz or glass plates, metal plates or metal foils, plastic films, sheets, or the like are used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, polysulfone or the like is preferable. When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too small, the organic electroluminescent element may be deteriorated by the outside air that has passed through the substrate, which is not preferable. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate is also a preferable method.

(anode)
The anode plays a role of hole injection into the layer on the light emitting layer side.
This anode is usually made of metal such as aluminum, gold, silver, nickel, palladium, platinum, metal oxide such as oxide of indium and / or tin, metal halide such as copper iodide, carbon black, or poly It is composed of conductive polymers such as (3-methylthiophene), polypyrrole and polyaniline.

  The anode is usually formed by a sputtering method, a vacuum deposition method, or the like. In addition, when forming an anode using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, and conductive polymer fine powder, an appropriate binder resin solution is used. An anode can also be formed by dispersing and coating the substrate. Furthermore, in the case of a conductive polymer, a thin film can be directly formed on a substrate by electrolytic polymerization, or an anode can be formed by applying a conductive polymer on a substrate (Appl. Phys. Lett., 60). Vol. 2711 (1992).

The anode usually has a single-layer structure, but it can also have a laminated structure composed of a plurality of materials if desired.
The thickness of the anode varies depending on the required transparency. When transparency is required, the visible light transmittance is usually 60% or more, preferably 80% or more. in this case,
The thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and is usually 1000 nm or less, preferably about 500 nm or less. When opaqueness is acceptable, the thickness of the anode is arbitrary, and the anode may be the same as the substrate. Furthermore, it is also possible to laminate different conductive materials on the anode.
For the purpose of removing impurities adhering to the anode and adjusting the ionization potential to improve the hole injection property, the anode surface is treated with ultraviolet (UV) / ozone, oxygen plasma or argon plasma. Is preferred.

(Hole injection layer)
The method for forming the hole injection layer in the present invention is not particularly limited, but the hole injection layer is preferably formed by a wet film formation method from the viewpoint of reducing dark spots. In addition, the wet film forming method is more industrially superior in that a homogeneous and defect-free thin film can be obtained as compared with the conventional vacuum deposition method, the time for formation is short.
When the hole injection layer is formed by a wet film formation method, the material for the hole injection layer is usually mixed with an appropriate solvent (a solvent for the hole injection layer) to form a composition for film formation (hole injection layer). Forming the composition for forming the hole injection layer), applying the composition for forming the hole injection layer onto a layer (usually an anode) corresponding to the lower layer of the hole injection layer, forming a film, and drying By doing so, a hole injection layer is formed.

(Hole transporting compound)
The composition for forming a hole injection layer usually contains at least a hole transporting compound and a solvent as a material for the hole injection layer.
As long as the hole transporting compound is a compound having a hole transporting property, which is usually used in a hole injection layer of an organic electroluminescence device, a monomer or the like may be a polymer compound or the like. Although it may be a low molecular weight compound, it is preferably a high molecular weight compound.

  The hole transporting compound is preferably a compound having an ionization potential of 4.5 eV or more and 6.0 eV or less from the viewpoint of a charge injection barrier from the anode to the hole injection layer. Examples of hole transporting compounds include aromatic amine derivatives, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, benzylphenyl derivatives, compounds in which tertiary amines are linked by a fluorene group, hydrazone derivatives, silazane derivatives, silanamines Derivatives, phosphamine derivatives, quinacridone derivatives, polyaniline derivatives, polypyrrole derivatives, polyphenylene vinylene derivatives, polythienylene vinylene derivatives, polyquinoline derivatives, polyquinoxaline derivatives, carbon and the like.

In the present invention, a derivative includes, for example, an aromatic amine derivative and includes an aromatic amine itself and a compound having an aromatic amine as a main skeleton. It may be a mer.
Of these, aromatic amine compounds are preferred from the viewpoints of amorphousness and visible light transmittance. An aromatic tertiary amine compound is particularly preferable. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and includes a compound having a group derived from an aromatic tertiary amine. The kind of the aromatic tertiary amine compound is not particularly limited, but from the viewpoint of uniform light emission due to the surface smoothing effect, a polymer compound having a weight average molecular weight of 1,000 or more and 1,000,000 or less (a polymer in which repeating units are linked) is more preferable. . Preferable examples of the aromatic tertiary amine polymer compound include a polymer compound having a repeating unit represented by the following formula (I).

(In formula (I), Ar ⁷ and Ar ⁸ each independently represent an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Ar ^{9 to} Ar ¹¹ each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Represents a linking group selected from the group of linking groups, and among Ar ^{7 to} Ar ¹¹ , two groups bonded to the same N atom may be bonded to each other to form a ring.

(In said each formula, Ar < ¹² > -Ar < ²² > represents each independently the aromatic hydrocarbon group which may have a substituent, or the aromatic heterocyclic group which may have a substituent. R ⁵ and R ⁶ each independently represents a hydrogen atom or a substituent.)
Ar ^{7 to} Ar ²² represent an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. These may be the same or different from each other. The aromatic hydrocarbon group and / or aromatic heterocyclic group of Ar ^{7 to} Ar ²² may further have a substituent. The molecular weight of the substituent is usually 400 or less, preferably about 250 or less. Ar ⁷ and Ar ⁸ are each independently derived from a benzene ring, a naphthalene ring, a phenanthrene ring, a thiophene ring, or a pyridine ring from the viewpoint of the solubility, heat resistance, hole injection / transport properties of the aromatic amine polymer. Group is preferable, and a phenyl group (a group derived from a benzene ring) and a naphthyl group (a group derived from a naphthalene ring) are preferable. Ar ^{9 to} Ar ¹¹ are each preferably a group derived from a benzene ring, a naphthalene ring, a triphenylene ring, or a phenanthrene ring, from the viewpoint of heat resistance and hole injection / transport properties including redox potential, A phenylene group (a group derived from a benzene ring), a biphenylene group (a group derived from a benzene ring), and a naphthylene group (a group derived from a naphthalene ring) are preferable.

Specific examples of the aromatic tertiary amine polymer compound having a repeating unit represented by the formula (I) include those described in, for example, International Publication No. 2005/088904 pamphlet. And a high molecular compound having a repeating unit.

Moreover, as a hole transportable compound, the material described in the term of the following (hole transport layer / first organic layer) can be used.
Furthermore, as a hole transporting compound, a conductive polymer (PEDOT / PSS) obtained by polymerizing 3,4-ethylenedioxythiophene (3,4-ethylenedioxythiophene), a polythiophene derivative, in high molecular weight polystyrene sulfonic acid. Is also preferred. Moreover, the end of this polymer may be capped with methacrylate or the like.

  The hole transporting compound used as the material for the hole injection layer may contain any one of these compounds alone, or may contain two or more. When two or more hole transporting compounds are contained, the combination thereof is arbitrary, but one or more aromatic tertiary amine polymer compounds and one or two other hole transporting compounds are used. It is preferable to use the above in combination.

(Electron-accepting compound)
The composition for forming a hole injection layer preferably contains an electron accepting compound. The electron-accepting compound is preferably a compound having an oxidizing power and the ability to accept one electron from the above-described hole transporting compound, specifically, a compound having an electron affinity of 4 eV or more is preferable, and 5 eV or more. The compound which is the compound of these is further more preferable. The electron-accepting compound is selected from the group consisting of, for example, triarylboron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, and salts of arylamines and Lewis acids. 1 type, or 2 or more types of compounds etc. which are mentioned. More specifically, an onium salt substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate or triphenylsulfonium tetrafluoroborate (WO 2005/089024) Iron (III) chloride (Japanese Patent Laid-Open No. 11-251)
No. 067), high valence inorganic compounds such as ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tris (pentafluorophenyl) borane (Japanese Patent Laid-Open No. 2003-31365); fullerene derivatives Iodine; polystyrene sulfonate ions, alkylbenzene sulfonate ions, sulfonate ions such as camphor sulfonate ions, and the like. These electron-accepting compounds can improve the conductivity of the hole injection layer by oxidizing the hole transport material. The content of the electron-accepting compound with respect to the hole transport material is usually 0.1 mol% or more, preferably 1 mol% or more. However, it is usually 100 mol% or less, preferably 40 mol% or less.

(solvent)
At least one of the solvents used in the wet film formation method is preferably a compound that can dissolve the material of the hole injection layer. The boiling point of the solvent is usually 110 ° C. or higher, preferably 140 ° C. or higher, more preferably 200 ° C. or higher, usually 400 ° C. or lower, especially 300 ° C. or lower. If the boiling point of the organic solvent is too low, the drying speed is high and the film quality may be deteriorated. Moreover, when the boiling point of the organic solvent is too high, it is necessary to increase the temperature of the high drying step. Therefore, it may adversely affect other layers and the glass substrate. Examples of the solvent include ether solvents, ester solvents, aromatic hydrocarbon solvents, amide solvents, and the like. Specifically, examples of the ether solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3- And aromatic ethers such as dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole.

Examples of the ester solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.
Examples of the aromatic hydrocarbon solvent include toluene, xylene, cyclohexylbenzene, 3-isopropylpropylphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene. Can be mentioned.

Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, and the like.
In addition, dimethyl sulfoxide and the like can also be used.
These solvent may use only 1 type and may use 2 or more types by arbitrary combinations and a ratio.
Among the solvents described above, a solvent having a high ability to dissolve the material of the hole injection layer (dissolution ability) or a high affinity with the material is preferable. This is because a composition having an excellent concentration for forming a film can be prepared by a wet film forming method by arbitrarily setting the concentration of the composition for forming a hole injection layer.

(concentration)
The concentration of the hole transporting compound in the composition for forming a hole injection layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.01% by weight or more, preferably in terms of film thickness uniformity. Is 0.1% by weight or more, more preferably 0.5% by weight or more, and usually 70% by weight or less, preferably 60% by weight or less, more preferably 50% by weight or less. If the concentration is too high, film thickness unevenness may occur. If the concentration is too low, defects may occur in the formed organic layer.

(Other things that may be included)
As a material for the hole injection layer, other components may be further contained in addition to the hole transporting compound and the electron accepting compound as long as the effects of the present invention are not significantly impaired. Examples of other components include various light emitting materials, electron transporting compounds, binder resins, and coating property improving agents. In addition, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

After preparing the composition for forming the hole injection layer, the composition is applied to the layer corresponding to the lower layer of the hole injection layer (usually an anode) by wet film formation, and dried to dry the hole. An injection layer is formed.
After film formation, it is usually dried by heating or the like. The heating means used in the heating step is not limited as long as the effects of the present invention are not significantly impaired. Examples of the heating means include a clean oven, a hot plate, infrared rays, a halogen heater, and microwave irradiation. Among them, a clean oven and a hot plate are preferable in order to uniformly apply heat to the entire film.

In the case of layer formation by vacuum deposition, one or more materials (hole transporting compound, electron accepting compound, etc.) are put in a crucible installed in a vacuum vessel (two or more materials are added). If it is used, put it in each crucible), evacuate the inside of the vacuum vessel to about 10 ⁻⁴ Pa with an appropriate vacuum pump, then heat the crucible (if using more than one material, heat each crucible) ), Evaporate by controlling the evaporation amount (evaporation is controlled by independently controlling the evaporation amount when two or more materials are used), and form a hole injection layer on the anode of the substrate placed facing the crucible Let In addition, when using 2 or more types of materials, they can also be put into a crucible, can be heated and evaporated, and can be used for hole injection layer formation.
The thickness of the hole injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

(Hole transport layer / first organic layer)
A hole transport layer is formed as a first organic layer on the hole injection layer.
The method for forming the hole transport layer according to the present invention is not particularly limited, but the hole transport layer is preferably formed by wet film formation from the viewpoint of reducing dark spots.

  The material that can be used for the hole transport layer is preferably a material that has a high hole transport ability and can efficiently transport injected holes. Therefore, it is preferable that the ionization potential is small, the transparency to visible light is high, the hole mobility is large, the stability is high, and impurities that become traps are not easily generated during manufacturing or use. In many cases, it is in contact with the light-emitting layer, so it is preferable not to quench the light emitted from the light-emitting layer or reduce the efficiency by forming an exciplex with the light-emitting layer.

  As a material of such a hole transport layer, any material that has been conventionally used as a constituent material of a hole transport layer may be used. For example, as a hole transport compound used in the above-described hole injection layer What was illustrated is mentioned. In addition, arylamine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silole derivatives, oligothiophene derivatives, condensed polycyclic aromatics Group derivatives, metal complexes and the like.

  Also, for example, polyvinylcarbazole derivatives, polyarylamine derivatives, polyvinyltriphenylamine derivatives, polyfluorene derivatives, polyarylene derivatives, polyarylene ether sulfone derivatives containing tetraphenylbenzidine, polyarylene vinylene derivatives, polysiloxane derivatives, polythiophenes Derivatives, poly (p-phenylene vinylene) derivatives, and the like. These may be any of an alternating copolymer, a random polymer, a block polymer, or a graft copolymer. Further, it may be a polymer having a branched main chain and three or more terminal portions, or a so-called dendrimer.

Of these, polyarylamine derivatives and polyarylene derivatives are preferred.
The polyarylamine derivative is preferably a polymer containing a repeating unit represented by the following formula (II). In particular, the polymer is preferably a polymer composed of a repeating unit represented by the following formula (II). In this case, Ar ^a or Ar ^b may be different in each repeating unit.

(In formula (II), Ar ^a and Ar ^b each independently represent an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent.)
Examples of the aromatic hydrocarbon group which may have a substituent include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, and an acenaphthene. Examples thereof include a group derived from a 6-membered monocyclic ring or a 2-5 condensed ring, such as a ring, a fluoranthene ring, a fluorene ring, and a group in which two or more rings are connected by a direct bond.

  Examples of the aromatic heterocyclic group which may have a substituent include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, and a carbazole ring. , Pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine Ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, sinoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring, etc. Or a group and the rings of from 2-4 fused rings include groups formed by connecting a direct bond or two or more rings.

Ar ^a and Ar ^b are each independently from a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a pyrene ring, a thiophene ring, a pyridine ring, and a fluorene ring from the viewpoint of solubility in organic solvents and heat resistance. A group derived from a group selected from the group consisting of two or more benzene rings connected to each other (for example, a biphenyl group or a terphenyl group) is preferred.

Among these, a group derived from a benzene ring (phenyl group), a group formed by connecting two benzene rings (biphenyl group), and a group derived from a fluorene ring (fluorenyl group) are preferable.
Examples of the substituent that the aromatic hydrocarbon group and aromatic heterocyclic group in Ar ^a and Ar ^b may have include an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, a dialkylamino group Group, diarylamino group, acyl group, halogen atom, haloalkyl group, alkylthio group, arylthio group, silyl group, siloxy group, cyano group, aromatic hydrocarbon ring group, aromatic heterocyclic group and the like.

As the polyarylene derivative, an arylene group such as an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent exemplified as Ar ^a or Ar ^b in the formula (II) is used as its repeating unit. The polymer which has is mentioned.
As a polyarylene derivative, the polymer which has a repeating unit which consists of following formula (III-1) and / or following formula (III-2) is preferable.

(In formula (III-1), R ^a , R ^b , R ^c and R ^d are each independently an alkyl group, an alkoxy group, a phenylalkyl group, a phenylalkoxy group, a phenyl group, a phenoxy group, an alkylphenyl group, Represents an alkoxyphenyl group, an alkylcarbonyl group, an alkoxycarbonyl group, or a carboxy group, and t and s each independently represent an integer of 0 to 3. When t or s is 2 or more, they are contained in one molecule. A plurality of R ^a or R ^b may be the same or different, and adjacent R ^a or R ^b may form a ring.)

(In Formula (III-2), R ^e and R ^f are each independently the same as R ^a , R ^b , R ^c or R ^d in Formula (III-1) above. Independently, it represents an integer of 0 to 3. When r or u is 2 or more, a plurality of R ^e and R ^f contained in one molecule may be the same or different, and adjacent R ^e or R ^f may form a ring, and X represents an atom or a group of atoms constituting a 5-membered ring or a 6-membered ring.)
Specific examples of X include an oxygen atom, a boron atom which may have a substituent, a nitrogen atom which may have a substituent, a silicon atom which may have a substituent, and a substituent. A phosphorus atom which may be substituted, a sulfur atom which may have a substituent, a carbon atom which may have a substituent, or a group formed by bonding these.

  The polyarylene derivative has a repeating unit represented by the following formula (III-3) in addition to the repeating unit represented by the following formula (III-1) and / or the following formula (III-2). Is preferred.

(In the formula (III-3), Ar ^{c to} Ar ^j each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent. Independently represents 0 or 1.)
Specific examples of Ar ^{c to} Ar ^j are the same as Ar ^a and Ar ^b in the formula (II).

Specific examples of the above formulas (III-1) to (III-3) and specific examples of polyarylene derivatives include those described in JP-A-2008-98619.
In the case of forming a hole transport layer by a wet film formation method, a hole transport layer forming composition is prepared in the same manner as the formation of the hole injection layer, and then the film is formed and heated and dried. The composition for forming a hole transport layer contains a solvent in addition to the hole transport compound. The solvent is the same as that used in the composition for forming a hole injection layer. The film forming conditions, heat drying conditions, and the like are the same as in forming the hole injection layer.

In addition, also when forming a positive hole transport layer by vacuum evaporation, the film-forming conditions etc. are the same as formation of the said positive hole injection layer.
The hole transport layer may contain various electron transport compounds, binder resins, coatability improvers, and the like in addition to the above hole transport compound as long as the effects of the present invention are not impaired.

  The hole transport layer may be a layer formed by crosslinking a crosslinkable compound. The crosslinkable compound is a compound having a crosslinkable group, which will be described later, and forms a network polymer compound by crosslinking. The crosslinkable compound may be a low molecular compound or a high molecular compound. The crosslinkable compound may have only 1 type, and may have 2 or more types by arbitrary combinations and ratios.

Moreover, a crosslinkable group means the group which reacts with the same or different group of the other molecule | numerator located in the vicinity, and produces | generates a novel chemical bond. For example, the group which reacts with the same or different group of the other molecule | numerator located in the vicinity by irradiation of a heat | fever and / or active energy ray, and produces | generates a novel chemical bond is mentioned.
Examples of crosslinkable groups include cyclic ethers such as oxetane groups and epoxy groups; unsaturated double bonds such as vinyl groups, trifluorovinyl groups, styryl groups, acrylic groups, methacryloyl groups, cinnamoyl groups; benzocyclobutene rings And monovalent group derived from the above.

There is no particular limitation on the number of crosslinkable groups that the monomer, oligomer or polymer having a crosslinkable group has, but it is usually less than 2.0, preferably 0.8 or less, more preferably 0.5 or less per charge transport unit. Number is preferred. This is to keep the relative dielectric constant of the charge transport film forming material within a suitable range. Moreover, if the number of crosslinkable groups is too large, reactive active species are generated, which may adversely affect other materials. Here, when the material forming the network polymer compound is a low molecular compound, the charge transport unit is a low molecular compound itself and indicates a skeleton (main skeleton) excluding a crosslinkable group. Even when other kinds of low molecular weight compounds are mixed, the main skeleton of each low molecular weight compound is shown. In the case where the material forming the network polymer compound is a polymer compound, in the case of a structure in which conjugation is broken organically, the repeated structure is used as a charge transport unit. Further, in the case of a structure in which conjugation is widely linked, the minimum repeating structure exhibiting charge transporting properties indicates the structure of a low molecular compound. For example, polycyclic aromatics such as naphthalene, triphenylene, phenanthrene, tetracene, chrysene, pyrene, perylene, fluorene, triphenylene, carbazole, triarylamine, tetraarylbenzidine, 1,4-bis (diarylamino) benzene, etc. It is done.

  Furthermore, it is preferable to use a hole transporting compound having a crosslinkable group as the crosslinkable compound. Examples of hole transporting compounds include nitrogen-containing aromatic compound derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives, phthalocyanine derivatives, porphyrin derivatives; triphenylamine derivatives Silole derivatives; oligothiophene derivatives, condensed polycyclic aromatic derivatives, metal complexes and the like. Among them, nitrogen-containing aromatic derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives; triphenylamine derivatives, silole derivatives, condensed polycyclic aromatic derivatives, metal complexes, etc. Particularly preferred are triphenylamine derivatives.

The molecular weight of the crosslinkable compound is usually 3,000,000 or less, preferably 1,000,000 or less, preferably 300 or more, more preferably 500 or more.
In order to form a hole transport layer by crosslinking a crosslinkable compound, a composition (composition for forming a hole transport layer) in which a crosslinkable compound is dissolved or dispersed in a solvent is usually prepared and subjected to wet film formation. Form a film and crosslink.

Preferred examples of such a crosslinkable compound include compounds described in JP 2008-248241 A, JP 2009-074074 A, JP 2009-196982 A, and International Publication No. 2009/102027 pamphlet. Can be mentioned.
Moreover, you may use the compound which has a dissociation group of an international publication 2009/102027 pamphlet instead of a crosslinkable group. The preferred molecular weight of the compound having a dissociating group is the same as the molecular weight of the compound having a crosslinkable group.

Preferable examples of the compound having a dissociating group include compounds described in International Publication No. 2009/102027 pamphlet.
Specific preferred examples of the crosslinkable compound and the compound having a dissociating group are shown below, but the present invention is not limited thereto.

(In the above formula, examples include a = 0.9, b = 0.1, etc.)

(In the above formula, examples include a = 0.9, b = 0.1, etc.)

(In the above formula, examples include a = 0.8, b = 0.2, etc.)

(In the above formula, for example, a = 0.475, b = 0.475, c = 0.025, d = 0.025).

(In the above formula, examples include a = 0.94, b = 0.06)

(In the above formula, examples include a = 0.5, b = 0.5, c = 0.7, and d = 0.3.)

  In addition to the crosslinkable compound, the composition may contain an additive that promotes the crosslinking reaction. Examples of additives that accelerate the crosslinking reaction include: crosslinking initiators and crosslinking accelerators such as alkylphenone compounds, acylphosphine oxide compounds, metallocene compounds, oxime ester compounds, azo compounds, onium salts; condensed polycyclic hydrocarbons; And photosensitizers such as porphyrin compounds and diaryl ketone compounds. Further, it may contain a coating property improving agent such as a leveling agent and an antifoaming agent; an electron accepting compound: a binder resin, and the like.

The solvent used in the composition is the same as that exemplified as the solvent for forming the hole injection layer. In the composition, the crosslinkable compound is usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, usually 50% by weight or less, preferably 20% by weight or less, more preferably. Contains 10% by weight or less.
After forming the composition, the crosslinkable compound is crosslinked to form a network polymer by heating and / or irradiation with active energy such as light. As a heating condition, the layer formed at 120 ° C. or higher, preferably 400 ° C. or lower is heated. The heating time is usually 1 minute or longer, preferably 24 hours or shorter. The heating means is not particularly limited, and means such as placing a laminated body having a deposited layer on a hot plate or heating in an oven is used. For example, conditions such as heating on a hot plate at 120 ° C. or more for 1 minute or more can be used.

  In the case of irradiation with active energy such as light, a method of irradiating directly using an ultraviolet / visible / infrared light source such as an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a halogen lamp, an infrared lamp, or the above-mentioned light source is incorporated. Examples include a mask aligner and a method of irradiation using a conveyor type light irradiation device. In active energy irradiation other than light, for example, there is a method of irradiation using a so-called microwave oven that irradiates a microwave generated by a magnetron. As the irradiation time, it is preferable to set conditions necessary for reducing the solubility of the film, but irradiation is usually performed for 0.1 seconds or longer, preferably 10 hours or shorter.

Heating and irradiation of active energy such as light may be performed individually or in combination. When combined, the order of implementation is not particularly limited.
The active energy irradiation including heating and light is preferably performed in an atmosphere containing no moisture such as a nitrogen gas atmosphere in order to reduce the amount of moisture contained in the layer and / or moisture adsorbed on the surface after implementation. For the same purpose, when combined with heating and / or irradiation with active energy such as light, it is particularly preferable to perform at least the step immediately before the formation of the organic light emitting layer in an atmosphere containing no moisture such as a nitrogen gas atmosphere.

  The thickness of the hole transport layer is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[bank]
The organic electroluminescent element of the present invention has a bank formed in a pattern on the first organic layer. The bank is provided for the purpose of partitioning a second organic layer, for example, a light emitting layer, or a cathode (second electrode). The shape of the bank pattern is not particularly limited, and is appropriately selected according to the shape of the second organic layer, the shape of the cathode, and the like.
Also, the cross-sectional shape of the bank is not particularly limited, and for example, the cross-sectional shape may be a rectangular shape, a semicircular shape, a reverse-tapered trapezoidal shape, a forward-tapered trapezoidal shape, or the like. There may be. Further, the shape viewed from the upper surface of the bank is not particularly limited, and the opening may have a rectangular shape, an elliptical shape, a rectangular shape with rounded corners, or a straight shape.

(1. Bank forming composition)
A composition for forming a bank (a composition for forming a bank) is not particularly limited as long as it is a composition capable of forming a bank in a desired pattern, but for example, a screen printing resist, a photoresist, or Examples include materials used for forming the first organic layer.

  Since the screen printing method can print the resin only on the necessary part directly, when the bank is formed by the printing method, the waste of the composition for forming the bank is relatively small and it is easy to deal with a large area. . Further, since no development step is required, there is an advantage that the influence of the developer or the like on the characteristics of the first organic layer is small. Accordingly, it is preferable to use a screen printing resist as the bank forming composition.

  Since photoresists are widely used, when photoresists are used as the bank forming composition, the fine processing accuracy is high, and further, selection of materials including positive, negative, and other types, exposure, development, baking By appropriately setting such conditions, there is an advantage that a cross-sectional shape such as a reverse tapered shape or a forward tapered shape trapezoidal shape can be produced relatively easily. Accordingly, it is preferable to use a photoresist as the bank forming composition.

Further, when the same material as that used for forming the first organic layer is used, for example, even when a residue of the bank forming composition remains on the first organic layer, the bank forming composition is Since it has a charge transport property, there is an advantage that unevenness in light emission when used as an element is small and the influence on the second organic layer can be reduced. Another advantage is that the manufacturing process can be simplified by forming a structure having a concave cross-sectional shape and using both the first organic layer and the bank by photolithography using a photomask.
In addition, as the bank forming composition, a composition other than the above composition may be used.
Hereinafter, although a photoresist is explained in full detail, this invention is not limited to this.

(2. Photoresist)
When a photoresist is used as the bank forming composition, examples of a material preferably contained in the photoresist include a binder resin, an ethylenically unsaturated compound, a photopolymerization initiator, and an amino compound.
These will be described in detail below.

(2-1. Binder resin)
The photoresist in the present invention preferably contains a binder resin. As the binder resin, a resin that can be developed with a developer is used. As the developer, an alkali developer is usually preferably used, so that the binder resin is preferably an alkali-soluble resin.

  Examples of the alkali-soluble resin include acrylic resin, carboxyl group-containing urethane resin, modified epoxy resin, modified novolac resin, cardo resin, reaction product of carboxyl group-containing vinyl resin and epoxy group-containing unsaturated compound, various types Examples thereof include resins containing an ethylenically unsaturated group and a carboxyl group, preferably an acrylic acid resin, a reaction product of a carboxyl group-containing vinyl resin and an epoxy group-containing unsaturated compound, an ethylenically unsaturated group And a carboxyl group-containing resin and a modified novolak resin.

In the following, the binder resin particularly preferably used among the above includes an acrylic acid resin, a reaction product of a carboxyl group-containing vinyl resin and an epoxy group-containing unsaturated compound, an ethylenically unsaturated group and a carboxyl group The resin to be used and the modified novolak resin will be further described in detail.
In the present invention, “(meth) acrylic acid” means that both acrylic acid and methacrylic acid are included, and “(meth) acrylate”, “(meth) acryloyl” and the like have the same meaning. . Moreover, what added "(poly)" in front of the monomer name means including both the said monomer and its polymer, and "(acid) anhydride", "(anhydrous) ... acid" Means to include both acids and their anhydrides.
Furthermore, (co) polymer means that both a polymer and a copolymer are included.
In the present invention, the “total solid content” means all components except the solvent among the constituent components of the photoresist of the present invention.

(2-1-1. Acrylic acid resin)
The binder resin contained in the photoresist in the present invention is preferably an acrylic resin.
The acrylic resin is a (co) polymer obtained by polymerizing a monomer having either a carboxyl group or a phenolic hydroxyl group on the side chain or main chain in terms of improving alkali solubility. preferable.
Examples of the monomer having either a carboxyl group or a phenolic hydroxyl group in the main chain or side chain include monomers obtained by adding an acid (anhydride) to hydroxyalkyl (meth) acrylate. Examples of the acid (anhydride) include (anhydrous) succinic acid, (anhydrous) phthalic acid, (anhydrous) maleic acid and the like.

  Examples of monomers obtained by adding an acid (anhydride) to hydroxyalkyl (meth) acrylate include succinic acid (2- (meth) acryloyloxyethyl) ester and adipic acid (2-acryloyloxyethyl) ester. Phthalic acid (2- (meth) acryloyloxyethyl) ester, hexahydrophthalic acid (2- (meth) acryloyloxyethyl) ester, and the like.

Furthermore, examples of monomers that can be copolymerized with the above monomers include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, cinnamic acid, maleic acid, fumaric acid, anhydrous Unsaturated group-containing carboxylic acids such as maleic acid and itaconic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, allyl (meth) acrylate, adamantyl (meth) acrylate, glycidyl (meth) acrylate, Esters of (meth) acrylic acid such as 2-ethylhexyl (meth) acrylate, compounds obtained by adding lactones such as ε-caprolactone and γ-butyrolactone to (meth) acrylic acid, acrylonitrile such as acrylonitrile and methacrylonitrile , (Meth) acrylamide, N-me Acrylamide, N, acrylamides such as N- dimethylacrylamide, vinyl acetate, vinyl propionate, vinyl cinnamate, include acid vinyl such as vinyl pivalate.
These may be used alone or in combination of two or more.

(2-1-2. Reaction product of carboxyl group-containing vinyl resin and epoxy group-containing unsaturated compound)
Another preferable binder resin contained in the photoresist in the present invention is a reaction product of a carboxyl group-containing vinyl resin and an epoxy group-containing unsaturated compound.

  Examples of carboxyl group-containing vinyl resins include (meth) acrylate- (meth) acrylic acid copolymers and styrene- (meth) acrylate- (meth) acrylic acid polymers, and epoxy group-containing unsaturated compounds. Examples include allyl glycidyl ether and glycidyl (meth) acrylate.

(2-1-3. Resin containing an ethylenically unsaturated group and a carboxyl group)
Still another preferred binder resin contained in the photoresist in the present invention includes a resin containing an ethylenically unsaturated group and a carboxyl group.
Examples of the resin containing an ethylenically unsaturated group and a carboxyl group include a copolymer of a compound having two or more unsaturated groups, an unsaturated carboxylic acid, and an unsaturated carboxylic acid ester as necessary. It is done.

  Examples of the compound having two or more unsaturated groups include allyl (meth) acrylate, 3-allyloxy-2-hydroxypropyl (meth) acrylate, cinnamyl (meth) acrylate, methallyl (meth) acrylate, and N, N-diallyl. (Meth) acrylamide, vinyl (meth) acrylate, 2-phenylvinyl (meth) acrylate, vinyl (meth) acrylamide and the like can be mentioned. Examples of unsaturated carboxylic acid or unsaturated carboxylic acid ester include (meth) acrylic acid. (Ester), (meth) acrylic acid (ester), etc. are mentioned.

(2-1-4. Modified novolak resin)
The binder resin contained in the photoresist in the present invention is preferably a modified novolak resin.
The modified novolac resin is a resin obtained by reacting a novolak resin with an unsaturated group-containing epoxy compound and then adding a hydroxyl group of the resulting reaction product and an (anhydrous) polybasic acid.

  As novolak resins, for example, phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, o-ethylphenol, m-ethylphenol, p-ethylphenol, benzoic acid At least one of phenols such as acid, 4-hydroxyphenylacetic acid, salicylic acid, etc. is used in the presence of an acid catalyst, for example, aldehydes such as formaldehyde, paraformaldehyde, acetaldehyde, furfural, or acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. Examples thereof include resins obtained by polymerizing one or more of ketones.

Further, a resol resin may be used instead of the novolac resin.
Examples of the unsaturated group-containing epoxy compound include glycidyl (meth) acrylate, (3,4-epoxycyclohexyl) methyl (meth) acrylate, glycidyloxy (poly) alkylene glycol (meth) acrylate, methyl glycidyl (meth) acrylate, (3,4-epoxycyclohexyl) vinyl and the like.

  The (anhydrous) polybasic acid is not particularly limited as long as it is a compound having a hydroxyl group and a group to be added, and known materials can be used. For example, maleic acid, succinic acid, itaconic acid, phthalic acid, tetrahydro Dibasic carboxylic acids such as phthalic acid, 5-norbornene-2,3-dicarboxylic acid, methyl-5-norbornene-2,3-dicarboxylic acid and their anhydrides; trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid , Polybasic carboxylic acids such as biphenyltetracarboxylic acid, and anhydrides thereof.

(2-1-5. Binder resin content, etc.)
The content of the binder resin in the photoresist is usually 5% by weight or more, preferably 10% by weight or more, more preferably 15% by weight or more, and usually 70% by weight or less, based on the total solid content excluding the solvent. Preferably it is 60 weight% or less, More preferably, it is 50 weight% or less. If the lower limit is not reached, sufficient hardness to form a bank cannot be obtained, and a bank having a desired shape may not be formed. Moreover, when this upper limit is exceeded, there exists a possibility that applicability | paintability and developability may fall.
One kind of the binder resin may be used alone, or two different kinds may be mixed and used.

(2-2. Ethylenically unsaturated compounds)
The photoresist in the present invention preferably contains an ethylenically unsaturated compound.
Although there is no restriction | limiting in particular as an ethylenically unsaturated compound, The difference of the solubility with respect to the developing solution of an exposure part and a non-exposure part becomes large in the image development process in below-mentioned (3. bank formation process), and it is on a board | substrate. A compound having two or more ethylenically unsaturated groups in the molecule is preferable in that the formed image pattern is formed in a desired shape, and the unsaturated group is a (meth) acryloyloxy group. More preferably derived.

  Examples of compounds having two or more ethylenically unsaturated groups in the molecule include esters of unsaturated carboxylic acids and polyhydroxy compounds, (meth) acryloyloxy group-containing phosphates, hydroxy (meth) acrylate compounds and poly Urethane (meth) acrylates with isocyanate compounds, and epoxy (meth) acrylates of (meth) acrylic acid or hydroxy (meth) acrylate compounds and polyepoxy compounds, preferably ester (meth) acrylates Or urethane (meth) acrylates, particularly preferably pentafunctional or higher functional groups such as dipentaerythritol hexa (meth) acrylate and dipentaerythritol penta (meth) acrylate.

The concentration of the ethylenically unsaturated compound in the photoresist is usually 5% by weight or more, preferably 10% by weight or more, and usually 80% by weight or less, preferably 70% by weight or less based on the total solid content excluding the solvent. It is. If the lower limit is not reached, the exposure process described later may not have sufficient curability by exposure, and a bank having a desired shape may not be formed. If the upper limit is exceeded, a bank having a desired shape cannot be formed. There is a fear.
The said ethylenically unsaturated compound may be used individually by 1 type, and may use 2 or more types different together.

(2-3. Photopolymerization initiator)
The photoresist in the present invention preferably contains a photopolymerization initiator.
The photopolymerization initiator is not particularly limited as long as it is a compound that polymerizes an ethylenically unsaturated group with actinic rays, and a known photopolymerization initiator can be used.
The concentration of the photopolymerization initiator in the photoresist is usually 0.01% by weight or more, preferably 0.1% by weight or more, more preferably 0.5% by weight or more, based on the total solid content excluding the solvent. Moreover, it is 30 weight% or less normally, Preferably it is 20 weight% or less. If the concentration of the photopolymerization initiator in the photoresist is excessively high, the adhesion with the first organic layer forming the bank may be reduced, and if the concentration is too low, the curability of the bank to be formed is reduced. There is a fear.

  The said photoinitiator may be used individually by 1 type, and may use 2 or more types different together.

(2-4. Amino compounds)
The photoresist in the present invention preferably contains an amino compound in terms of promoting the crosslinking of the photoresist by exposure.
As the amino compound, a known compound can be used, and examples thereof include an amino compound having at least two methylol groups as functional groups and alkoxymethyl groups obtained by subjecting it to alcohol condensation modification having 1 to 8 carbon atoms.
The concentration of the amino compound in the photoresist is usually 40% by weight or less, preferably 30% by weight or less, and usually 0.5% by weight or more, preferably 1% by weight or more based on the total solid content excluding the solvent. It is. If the concentration is too high, the storage stability of the photoresist may be affected. If the concentration is too low, the curability of the formed bank may be reduced.
The said amino compound may be used individually by 1 type, and may use 2 or more types together.

(2-5. Other ingredients)
The photoresist in the present invention may further contain other components. Examples of other components include a liquid repellent, a colorant, a surface modifier, a development improver, an ultraviolet absorber, a polymerization inhibitor, an antioxidant, a silane coupling agent, an epoxy compound, other resins, and a solvent. .

(2-5-1. Liquid repellent)
The photoresist in the present invention preferably contains a liquid repellent.
The liquid repellent is not particularly limited as long as it has an effect of imparting liquid repellency to the bank. For example, a fluorine-containing compound or a silicon-containing compound may be mentioned, but when an organic solvent is used as a solvent of the composition, Compounds are preferred.

The fluorine-containing compound is not particularly limited and may be a low molecular compound or a high molecular compound, and examples thereof include a compound containing a perfluoroalkyl group or a perfluoropolyether group.
Examples of the compound containing a perfluoroalkyl group include JP-A-7-35916, JP-A-11-281815, International Publication No. 2004-042474, JP-A-2005-60515, JP-A-2005-315984. And the compounds described in JP-A-2006-71086, etc .;
BYK-340 (manufactured by Big Chemie), Modiper F200, F600, F3035 (manufactured by NOF Corporation) Footgent M series, S series, F series, G series, D series, oligomer series (manufactured by Neos) Examples of resins that are copolymerized with a perfluoro group-containing acrylic monomer such as Unidyne (manufactured by Daikin Industries), trifluoropropyltrichlorosilane (manufactured by Shin-Etsu Silicone), Surflon S-386 (manufactured by AGC Seimi Chemical Co., Ltd.), etc. .

Further, as a resin used as a liquid repellent (hereinafter referred to as “ink-repellent resin”), for example, a fluorinated epoxy resin, a fluorinated polyimide resin, a fluorinated polyamide resin, a fluorinated polyurethane resin, a fluorinated siloxane resin, and These modified resins are also included.
Further, as the liquid repellent, it is preferable to use an ink repellent resin in that there is no possibility that the liquid repellent flows out during the bank formation process, for example, in the development process. Further, the ink repellent resin is preferably an ink repellent resin having a crosslinkable group as a side chain (hereinafter referred to as “crosslinkable group-containing ink repellent resin”).

The crosslinkable group-containing ink-repellent resin is not particularly limited. For example, MegaFac RS-101, RS-102, RS-105, RS-401, RS-402, RS-501, RS-502 (and above, DIC), OPTOOL DAC (Daikin Industries), perfluoro (meth) acrylate, perfluorodi (meth) acrylate, and the like.
One of the above liquid repellents may be used alone, or two or more may be used in combination.

The concentration of the liquid repellent in the present invention is usually 0.001% by weight or more based on the total solid content excluding the solvent of the photoresist when the fluorine atom content in the liquid repellent is 10% by weight or more, preferably It is 0.05% by weight or more, usually 10% by weight or less, preferably 6% by weight or less.
When the fluorine atom content is less than 10% by weight, it is usually 0.1% by weight or more, preferably 1% by weight or more, and usually 70% by weight or less, preferably 50% by weight or less.

Below this lower limit, the ink repellency of the bank becomes insufficient, and when the second organic layer (light emitting layer) described later is formed, a second organic layer composition (light emitting layer forming composition) is formed. May flow out to the area partitioned by the bank. On the other hand, if the upper limit is exceeded, development in a later-described development process becomes difficult, and it may be difficult to form a bank having a desired shape.
The said liquid repellent may be used individually by 1 type, and may use 2 or more types together.

(2-5-2. Colorant)
The photoresist in the present invention may contain a colorant.
As the colorant, a known colorant can be used, and examples thereof include pigments and dyes, but a black colorant is preferable in that a clearer pixel can be obtained by coloring the bank black. . Examples of the black colorant include black dyes, carbon black, titanium black, and organic pigments.

The concentration of the colorant in the present invention is usually 60% by weight or less, preferably 40% by weight or less, based on the total solid content excluding the solvent in the photoresist.
When a pigment is used as the colorant, it may further contain a dispersant or a dispersion aid in terms of preventing the pigment from aggregating in the photoresist.
The said coloring agent may be used individually by 1 type, and may use 2 or more types together.

(2-5-3. Surface modifier, development improver)
The photoresist in the present invention may contain a surface modifier and a development improver.
The surface modifier and the development improver are not particularly limited, and known materials can be used. Examples thereof include cationic, anionic, nonionic, fluorine-based and silicon-based surfactants. .

The concentration of the surface modifier or development improver is usually 20% by weight or less, preferably 10% by weight or less, based on the total solid content excluding the solvent.
The above surface modifiers and development improvers may be used alone or in combination of two or more.

(2-5-4. Polymerization inhibitor, antioxidant)
The photoresist in the present invention preferably contains a polymerization inhibitor or an antioxidant from the viewpoint of improving the stability of the photoresist.
Examples of the polymerization inhibitor include hydroquinone and methoxyphenol.
Examples of the antioxidant include hindered phenol compounds such as 2,6-di-tert-butyl-4-cresol (BHT).
The concentrations of the polymerization initiator and the antioxidant are usually 5 ppm or more and 1000 ppm or less, preferably 10 ppm or more and 600 ppm or less, based on the total solid content excluding the solvent in the photoresist.

If this concentration is too small, the photoresist may be polymerized or oxidized, making it difficult to use as a bank forming material. Moreover, when this density | concentration is too large, there exists a possibility that hardening of the photoresist by the below-mentioned heating process may become inadequate.
The said polymerization inhibitor and antioxidant may be used individually by 1 type, and may use 2 or more types together.

(2-5-5. Silane coupling agent)
The photoresist in the present invention may contain a silane coupling agent in terms of improving the adhesion between the formed bank and the substrate.
Examples of the silane coupling agent include epoxy-based, methacrylic-based, amino-based, and imidazole-based silane coupling agents, and among them, epoxy-based and imidazole-based silane coupling agents are preferable.

The concentration of the silane coupling agent is usually 20% by weight or less, preferably 15% by weight or less, based on the total solid content excluding the solvent in the photoresist.
The said silane coupling agent may be used individually by 1 type, and may use 2 or more types together.

(2-5-6. Epoxy compound)
The photoresist in the present invention may contain an epoxy compound in terms of improving the curability of the formed bank and the adhesion between the formed bank and the substrate.
As the epoxy compound, a compound containing a repeating unit having an epoxy group is preferable, and a known material can be used. For example, a polyglycidyl ether compound and a polycarboxylic acid compound obtained by reacting a polyhydroxy compound and epichlorohydrin can be used. Examples thereof include polyglycidyl ester compounds obtained by reacting epichlorohydrin, polyglycidylamine compounds obtained by reacting polyamine compounds and epichlorohydrin, and the like.

  The concentration of the epoxy compound is usually 40% by weight or less, preferably 30% by weight or less, based on the total solid content excluding the solvent in the photoresist. If the concentration is too large, the storage stability of the photoresist may be affected.

(2-5-7. Solvent)
The photoresist in the present invention further contains a solvent.
The solvent contained in the photoresist is not particularly limited, and a solvent for dissolving or dispersing the photoresist and each component is appropriately selected. For example, water, diisopropyl ether, mineral spirit, n-pentane, amyl Ether, ethyl caprylate, n-hexane, diethyl ether, isoprene, ethyl isobutyl ether, butyl stearate, n-octane, Valsol # 2, Apco # 18 solvent, diisobutylene, amyl acetate, butyl butyrate, apcocinner, butyl ether , Diisobutylketone, methylcyclohexene, methylnonylketone, propyl ether, dodecane, Socal solvent No. 1 and no. 2, amyl formate, dihexyl ether, diisopropyl ketone, Solvesso # 150, butyl acetate (n, sec, t), hexene, shell TS28 solvent, butyl chloride, ethyl amyl ketone, ethyl benzoate, amyl chloride, ethylene glycol diethyl ether , Ethyl orthoformate, methoxymethylpentanone, methyl butyl ketone, methyl hexyl ketone, methyl isobutyrate, benzonitrile, ethyl propionate, methyl cellosolve acetate, methyl isoamyl ketone, methyl isobutyl ketone, propyl acetate, amyl acetate, Amyl formate, cyclohexyl acetate, bicyclohexyl, diethylene glycol monoethyl ether acetate, diethylene glycol mono Chill ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether, dipentene, methoxymethylpentanol, methyl amyl ketone, methyl isopropyl ketone, propyl propionate, propylene glycol-t-butyl ether, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, Carbitol, cyclohexanone, ethyl acetate, propylene glycol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, dipropylene Glycol monoethyl ether, dipropylene glycol monomethyl ether, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, 3-methoxypropionic acid, 3-ethoxypropionic acid, ethyl 3-ethoxypropionate, 3-methoxypropionic acid Methyl, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, dipropylene glycol monomethyl ether, ethylene glycol acetate, methyl carbitol, ethyl carbitol, butyl carbitol, ethylene glycol mono Butyl ether, propylene glycol-t-butyl ether, 3-methyl-3-methoxybutanol, tripropylene group Call methyl ether, 3-methyl-3-methoxybutyl acetate, 3-methoxybutyl acetate, and the like.

The boiling point of the solvent contained in the photoresist is usually 60 ° C. or higher, preferably 70 ° C. or higher, and usually 280 ° C. or lower, preferably 260 ° C. or lower.
The solvent is used so that the ratio of the total solid content in the photoresist solution is usually 10% by weight or more and usually 90% by weight or less.
The said solvent may be used individually by 1 type, and 2 different types may be mixed and used for it.

(3. Bank formation process)
Hereinafter, although a bank formation process is explained in full detail, unless the effect of the present invention is spoiled, other processes may be included.
The bank forming step is appropriately selected depending on the material. For example, when the bank-forming composition is a photoresist, the bank-forming composition (photoresist) is formed on the first organic layer, and exposed and developed in a desired pattern shape using a photomask or the like. Thus, a desired bank can be formed. Hereinafter, a case where a bank is formed by exposing and developing with a photomask or the like in a target pattern using a photoresist will be described as an example.

(3-1. Application process)
On the first organic layer (hole transport layer) formed on the hole injection layer, the bank-forming composition is usually formed on the entire surface of the first organic layer by a wet film formation method. .
The method of the wet film forming method of the photoresist is not limited as long as the effects of the present invention are not significantly impaired.
The wet film forming method is as described above, and among them, the die coating method is preferable.

(3-2. Pre-baking process)
In the bank formation step, if necessary, a pre-bake step may be performed after exposure using a photoresist and before exposure.
The pre-bake process is performed for the purpose of removing the solvent of the photoresist immediately after forming the photoresist.

  The conditions for the pre-baking step are appropriately selected depending on the type of photoresist, but the temperature in the pre-baking step is usually room temperature or higher, preferably 40 ° C. or higher, and is usually 200 ° C. or lower, preferably 150 ° C. or lower. When this upper limit is exceeded, the crosslinking reaction of the photoresist is accelerated, and there is a possibility that development into a desired shape cannot be performed. On the other hand, if the lower limit is not reached, the solvent may not be sufficiently removed, and the bank may not be formed in a desired shape.

  The baking time in the pre-baking step is usually 1 second or longer, preferably 10 seconds or longer, and is usually 30 minutes or shorter, preferably 20 minutes or shorter. If this upper limit is exceeded, the crosslinking reaction of the photoresist may be accelerated by long-time heating, and development may not be possible. If this lower limit is not reached, the solvent is not sufficiently removed and a bank having a desired shape is formed. There is a risk that it will not be possible.

Although there is no restriction | limiting in particular about a heating means, Active energy ray irradiation, such as a hotplate, oven, infrared rays, and electromagnetic waves, etc. are mentioned.
The atmosphere during heating may be performed in the air, or in dry air having a dew point of less than 0 ° C. to prevent moisture from being re-adsorbed after post-baking or oxidation of the bank or the substrate at high temperature. Alternatively, it may be performed in an inert gas such as nitrogen, or may be performed under a reduced pressure of less than 0.1 MPa.

Further, vacuum drying may be performed.
The time of vacuum drying is not particularly limited as long as the effect of the present invention is not impaired, but wet film formation is performed using a photoresist from the viewpoint that film thickness unevenness caused by convection is suppressed and a uniform film can be easily formed. Immediately after that, it is preferably performed before the pre-baking step.
The degree of vacuum for vacuum drying is usually less than atmospheric pressure, preferably less than the vapor pressure of the solvent contained in the photoresist.

(3-3. Exposure process)
In the method for manufacturing an organic electroluminescent element of the present invention, the bank forming step includes an exposure step after forming a film using the photoresist.
The exposure conditions and the like in the exposure process are appropriately selected according to the type of the above-mentioned photoresist, etc. For example, with respect to the exposure wavelength, g-line (wavelength 436 nm), i-line (wavelength 365 nm), broad (g, h, 3 wavelengths of i-line), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F2 excimer laser (wavelength 157 nm) and the like can be selected.
Among these, it is preferable to use g-line, i-line, or broad using a discharge lamp or the like as a light source from the required resist line width and the simplicity of handling equipment.
As for the exposure amount, an appropriate condition is usually selected in order to obtain a desired bank shape, but it is preferably ² J / cm ² or less from the viewpoint of exposure time.

(3-4. Development process)
When forming a bank using a photoresist, it usually has a development step after the exposure step. The developer used in the development step is appropriately selected depending on the type of the photoresist, but an aqueous solution of an alkaline compound or an organic solvent is used. In particular, it is preferable to use a developer containing an alkaline compound, a polar organic solvent, and water in that the residue of the bank forming composition is reduced.

That is, the method for producing an organic electroluminescent element according to the second aspect of the present invention has a developing step in the step of forming a bank, and in the developing step, a developer containing an alkaline compound, a polar organic solvent, and water ( In the following, the organic electroluminescence device manufacturing method is characterized in that the development is performed simply using “sometimes referred to as“ developer in the second aspect of the present invention ”).
When it has the process of wash | cleaning with the polar organic solvent mentioned later (namely, 1st of this invention), you may develop with developers other than the developer in the 2nd of this invention, but the residue of the composition for bank formation It is preferable to develop using the developer of the present invention from the viewpoint that the effect of the present invention is obtained.
The development step refers to a step of forming an image pattern (that is, a bank) on the first organic layer using a solvent or a solution, and usually has after the above exposure step.
Hereinafter, the development step in the second of the present invention will be described in detail.

(3-4-1. Developer)
The developer in the second aspect of the present invention is a developer containing an alkaline compound, a polar organic solvent, and water.
Examples of the alkaline compound include inorganic alkaline compounds and organic alkaline compounds. Examples of the inorganic alkaline compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, Sodium silicate, potassium silicate, sodium metasilicate, sodium phosphate, potassium phosphate, sodium hydrogen phosphate, potassium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium hydroxide, etc.
Organic alkaline compounds include, for example, mono-di- or triethanolamine, mono-di- or trimethylamine, mono-di- or triethylamine, mono- or diisopropylamine, n-butylamine, mono-di -Or triisopropanolamine, ethyleneimine, ethylenediimine, tetramethylammonium hydroxide (TMAH), choline and the like.

Said alkaline compound may be used individually by 1 type, and 2 or more types different may be mixed and used for it. In addition, when it remains in an organic layer, it is preferable to use an organic alkaline compound by the point which does not have a bad influence on an organic electroluminescent element more.
The polar organic solvent is preferably an organic solvent composed of an organic compound having an oxygen atom in the molecule.

The organic solvent comprising an organic compound having an oxygen atom in the molecule is specifically an organic solvent comprising an organic compound having at least one of a hydroxyl group, a carbonyl group, an ether bond, and an ester bond in the molecule. .
Examples of the organic solvent composed of an organic compound having a hydroxyl group include monohydric alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-hexanol, 2-ethylhexanol, and cyclohexanol, diethylene glycol, propylene glycol, and the like. Glycols of
Examples of the organic solvent composed of an organic compound having a carbonyl group include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.
Examples of the organic solvent consisting of an organic compound having an ether bond include tetrahydrofuran, dioxane, dimethoxyethane, diethoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, anisole, and the like.
Examples of the organic solvent made of an organic compound having an ester bond include ethyl acetate, isopropyl acetate, butyl acetate, 2-ethylhexyl acetate and the like.

  Examples of the organic solvent comprising an organic compound having a plurality of structures selected from the group consisting of a hydroxyl group, a carbonyl group, an ether bond, and an ester bond in one molecule include, for example, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether , Ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol dimethyl ether, Ethyl acetoacetate, methyl lactate, ethyl lactate, 3 Methyl methoxypropionate, diacetone alcohol, dimethylformamide, dimethylacetamide, N- methylpyrrolidone and the like.

  Of the above specific examples, methanol, ethanol, 1-propanol, 2-propanol, tetrahydrofuran, dioxane, dimethoxyethane, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether are dissolved in water. When rinsing is performed for the purpose of removing the solvent, pure water can be used as the rinsing liquid.

Furthermore, monohydric alcohols having 1 to 3 carbon atoms such as methanol, ethanol, 1-propanol, and 2-propanol are particularly preferable from the viewpoint of ease of handling.
The concentration of the alkaline compound contained in the developer of the present invention is usually 0.0001% by weight or more, preferably 0.005% by weight or more, more preferably 0.01% by weight or more, and usually 50% by weight or less, preferably It is 20 weight% or less, More preferably, it is 10 weight% or less.

If this upper limit is exceeded, there is a risk that the substrate and the organic layer will be adversely affected, or the bank may not be formed in a desired shape. On the other hand, if the lower limit is not reached, the development process takes a long time, which may cause industrial disadvantages.
The polar organic solvent contained in the developer of the present invention is usually 0.01% by weight or more, preferably 0.1% by weight or more, more preferably 1% by weight or more, and usually 80% by weight or less, preferably 50% by weight. Hereinafter, it is more preferably 30% by weight or less.

If this upper limit is exceeded, there is a possibility that a bank having a desired shape cannot be obtained. On the other hand, if the lower limit is not reached, the development is not sufficient and the residue of the bank-forming composition remains and the effects of the present invention may not be obtained.
The water contained in the developer of the present invention is usually 5% by weight or more, preferably 10% by weight or more, more preferably 20% by weight or more, and usually less than 100% by weight, preferably 99% by weight or less.

  If this upper limit is exceeded, the concentration of the alkaline compound and the polar organic solvent will be low, so that the development will be insufficient, and the residue of the bank-forming composition will remain and the effects of the present invention may not be obtained. If the lower limit is not reached, the photoresist to be removed after the exposure process may not be dissolved in the developer and reattached as a precipitate, which may adversely affect the characteristics of the obtained device.

The boiling point of the polar organic solvent contained in the developer of the present invention is usually 40 ° C. or higher, preferably 60 ° C. or higher, and usually 300 ° C. or lower, preferably 200 ° C. or lower. If this upper limit is exceeded, the viscosity is too high and the formed bank and organic layer are difficult to wet with the polar organic solvent, and the effects of the present invention may not be obtained. On the other hand, if the lower limit is not reached, the evaporation of the polar organic solvent is too early and the treatment becomes insufficient, and the effects of the present invention may not be obtained.

The molecular weight of the polar organic solvent in the present invention is usually 25 or more, preferably 30 or more, and usually 300 or less, preferably 200 or less. If this upper limit is exceeded, the boiling point becomes too high and the above problem may occur. On the other hand, if the lower limit is not reached, the boiling point of the solvent becomes too low and the above problem may occur.
The dielectric constant of the polar organic solvent in the present invention is usually 3.0 or more, preferably 4.0 or more, and usually 60 or less, preferably 40 or less. When the above range is exceeded, the development is not sufficiently performed, and a residue of the bank forming composition remains, and the effects of the present invention may not be obtained.

In the present invention, the solubility of the polar organic solvent in water is usually 0.1 wt% or more, preferably 1.0 wt% or more, ideally there is no upper limit, and the solubility in water is preferably higher. Below this lower limit, the effects of the present invention may not be obtained.
The developer of the present invention may further contain a surfactant, a buffering agent, a complexing agent and the like.
Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, monoglyceride alkyl esters; alkylbenzenesulfonic acid Anionic surfactants such as salts, alkylnaphthalene sulfonates, alkyl sulfates, alkyl sulfonates, sulfosuccinate esters; amphoteric surfactants such as alkylbetaines and amino acids.

Moreover, when performing the process wash | cleaned with the below-mentioned polar organic solvent (namely, 1st of this invention), solvents or solutions other than the developing solution of this invention can be used as a developing solution.
In the first aspect of the present invention, examples of the solvent or solution that can be used as the developer include an aqueous solution of an alkaline compound and an organic solvent.
When using the developing solution which consists of the aqueous solution of an alkaline compound, the alkaline compound quoted with the developing solution of the said this invention can be used as an alkaline compound.

  In the case of developing using only an organic solvent, there is no particular limitation, and a known organic solvent used as a developer can be used. The polar organic solvent in the present invention may be used, and a nonpolar solvent, for example, Aliphatic hydrocarbon solvents such as hexane and cyclohexane, and aromatic hydrocarbon solvents such as toluene and xylene may be used. When developing using only an organic solvent, one type may be used alone, or two or more different types may be mixed and used.

Development conditions are appropriately selected depending on the type of the photoresist.
The development temperature in the development step is not particularly limited, but is usually 10 ° C or higher, preferably 15 ° C or higher, and usually 100 ° C or lower, preferably 50 ° C or lower, more preferably 45 ° C or lower.
The development method is not particularly limited, and examples include immersion development, spray development, brush development, and ultrasonic development.

When the substrate is immersed in a developer (immersion development), the substrate is usually immersed in a developer heated to room temperature or higher and usually 100 ° C. or lower for a predetermined time. In this case, the substrate may be swung or the developer may be agitated in order to shorten the development time or to stably develop a plurality of substrates without variation during mass production.
In addition, when the developer is sprayed onto the substrate (spray development), development is performed by spraying using the developer heated to usually room temperature or higher and usually 100 ° C. or lower.

Development is performed to prevent the bank formed in a desired shape from being excessively developed and changed into an undesired shape by depositing the developer on the exposed photoresist over the required time. For the purpose of removing the developer after the completion and for the purpose of preventing the components contained in the developer from adhering to or remaining in the first organic layer or bank, a rinsing treatment may be usually performed after the development.

The rinsing process is performed by a method of immersing in a rinsing liquid or pouring the rinsing liquid on a substrate in a rod shape or a shower shape. The rinsing liquid is appropriately selected depending on the type of the photoresist, but a solvent or solution that does not contain the polar organic solvent in the present invention is used. Usually, ultrapure water is used as the rinse liquid.
If the rinsing liquid contains impurities that affect the characteristics of the organic electroluminescence device, it affects the driving thin film transistor (TFT) characteristics in the active driving organic electroluminescence device panel, and the obtained organic electroluminescence device May affect the device characteristics, such as device voltage, light emission efficiency, and drive life.

Examples of the impurities include metal ions such as sodium, potassium, calcium, magnesium, zinc, copper, iron, aluminum, and palladium, or metal oxides, metal compounds, or organic compounds including polymers, bacteria, microorganisms, and the like. Such dead bodies are listed.
Examples of particularly undesirable impurities include sodium ions, potassium ions, magnesium ions, zinc ions, iron ions, copper ions, aluminum ions, metal ions such as palladium ions, and organic halides. Among these, metal ions and organic halides having a boiling point of 150 ° C. or higher are not preferable because they are likely not to be removed even by a heating step described later. The concentration of these impurities in the rinsing solution is usually reduced to 0.1% or less, preferably 100 ppm or less, more preferably 1 ppm or less. Since it is preferably not included, the lower limit value is ideally 0.

Further, after the development or rinsing process, the developer or rinse liquid remaining on the substrate may be removed. The removal method is not particularly limited. For example, the substrate may be rotated by spinning, or a gas may be sprayed onto the substrate. If the rinse liquid is a volatile solvent, vacuum drying may be performed. .
When the method of removing the rinsing liquid is a method of rotating by spin, the rotation speed is usually 10 rpm or more, preferably 100 rpm or more, and usually 10,000 rpm or less, preferably 5000 rpm or less. When this upper limit is exceeded, there is a risk of disadvantages from an industrial point of view, and when this lower limit is exceeded, there is a risk that the developer or rinsing liquid remaining on the substrate may not be sufficiently removed.

Further, in the case of the method of rotating by spin, the number of rotations is usually 1 rotation or more, preferably 2 rotations or more, and usually 10,000 rotations or less and 5000 rotations or less. Within the above range, the developer or rinse solution remaining on the substrate is sufficiently removed.
When the method of removing the rinsing liquid is a method of blowing a gas, the gas to be used is not particularly limited, and examples thereof include air, dry air, nitrogen, argon, and other inert gases. Usually, air, dry air, Nitrogen is particularly preferable from the viewpoint of ease of handling. Moreover, it is preferable that the gas to be used is used by removing a fine particle by installing a filter in the middle of the piping. Since the filter effectively removes fine particles, it is preferable to use a filtration accuracy of 0.01 μm. The pressure for blowing the gas is usually at least atmospheric pressure, preferably at least 0.11 MPa, and usually at most 2 MPa, preferably at most 1 MPa.
If this upper limit is exceeded, the gas pressure may be too strong and the bank may peel or deform. If the lower limit is not reached, the gas pressure is too weak to remove the developer or rinse liquid adhering to the substrate. There is a fear.

(3-5. Step of washing with polar organic solvent)
The method for producing an organic electroluminescent element according to the first aspect of the present invention includes a step of washing with a polar organic solvent (hereinafter referred to as “polarity”) between a development step and a heating step performed after the step of forming a bank. It is sometimes referred to as an “organic solvent cleaning step”.).

In addition, the method for producing an organic electroluminescent element of the present invention has a polar organic solvent washing step when it is developed using the developer of the present invention in the developing step (that is, the second of the present invention). However, it is preferable to have a polar organic solvent washing step in that the residue of the bank forming composition is further reduced.
Hereinafter, although the polar organic solvent washing | cleaning process is explained in full detail, about this process, it is not limited to the case where a photoresist is used as a composition for bank formation.

(3-5-1. Polar organic solvent)
The polar organic solvent used in the polar organic solvent washing step is the same as the polar organic solvent described in the above section (3-4. Development step), and preferred examples are also the same.
(3-5-2. Physical properties of polar organic solvents, etc.)
The boiling point of the polar organic solvent in the present invention is usually 40 ° C. or higher, preferably 60 ° C. or higher, and usually 300 ° C. or lower, preferably 200 ° C. or lower. If this upper limit is exceeded, the polar organic solvent may not be removed by drying after washing with the polar organic solvent or the heating step described later, or the formed bank or organic layer may be difficult to wet with the polar organic solvent. Thus, the effects of the present invention may not be obtained. On the other hand, if the lower limit is not reached, the evaporation of the polar organic solvent is too early and the treatment becomes insufficient, and the effects of the present invention may not be obtained.

The molecular weight of the polar organic solvent in the present invention is usually 25 or more, preferably 30 or more, and usually 300 or less, preferably 200 or less. If this upper limit is exceeded, the boiling point becomes too high and the above problem may occur. On the other hand, if the lower limit is not reached, the boiling point of the solvent becomes too low and the above problem may occur.
The dielectric constant of the polar organic solvent in the present invention is usually 3.0 or more, preferably 4.0 or more, and usually 60 or less, preferably 40 or less. When the above range is exceeded, the residue of the bank forming composition remaining on the organic layer is not sufficiently removed, and the effects of the present invention may not be obtained.

In the present invention, the solubility of the polar organic solvent in water is usually 0.1 wt% or more, preferably 1.0 wt% or more, ideally there is no upper limit, and the solubility in water is preferably higher. Below this lower limit, the effects of the present invention may not be obtained.
One of the above polar organic solvents may be used alone, or two different types may be mixed and used.

In addition, the polar organic solvent in the present invention may be used in combination with other polar organic solvents that can be mixed with the above polar organic solvent within a range not impairing the effects of the present invention. You may mix and use with water.
Examples of other nonpolar organic solvents that may be mixed with the polar organic solvent include aliphatic hydrocarbon solvents such as hexane and cyclohexane, and aromatic hydrocarbon solvents such as toluene and xylene. .

When the polar organic solvent in the present invention is mixed with the above water or nonpolar solvent, the blending ratio of the polar organic solvent in the present invention is usually 50% by weight or more, preferably 80% by weight or more, more preferably 90% by weight. % And the upper limit is 100% by weight.
Within the above-mentioned range, it is industrially advantageous and preferable in that the cleaning effect by the polar organic solvent is sufficient and the cleaning can be completed in a short time.

(3-5-3. Method of washing with polar organic solvent)
The method of washing with a polar organic solvent is not particularly limited as long as the effects of the present invention are not impaired. For example, the substrate may be immersed in the polar organic solvent, or the polar organic solvent may be sprayed and sprayed onto the substrate. .
(3-5-3-1. When soaking)
When the substrate is immersed in a polar organic solvent, the temperature of the polar organic solvent is not less than the melting point of the normally used polar organic solvent, preferably 0 ° C. or more, and not more than the boiling point of the commonly used polar organic solvent, preferably 200 ° C. or less. is there. If this upper limit is exceeded, the bank-forming composition may be decomposed or dissolved. If the lower limit is not reached, the solubility of the residue of the bank-forming composition is reduced, and a bank is formed by coagulation of moisture. There is a risk that defects may occur in the organic layer or bank, which is the lower layer, or the effects of the present invention cannot be obtained.

The immersion time is usually 0.5 seconds or longer, preferably 1 second or longer, and usually 5 minutes or shorter, preferably 3 minutes or shorter. If the upper limit is exceeded, the organic layer, which is the lower layer forming the bank, may be deteriorated, or the bank may be deteriorated. On the other hand, if the lower limit is not reached, the removal of the residue of the bank forming composition becomes insufficient, and the effects of the present invention may not be obtained.
Furthermore, in order to shorten the processing time or to stably develop a plurality of substrates without variation during mass production, the substrates may be shaken or the polar organic solvent may be stirred. Further, immersion may be performed by applying ultrasonic waves.

(3-5-3-2. When a polar organic solvent is sprayed onto a substrate)
When the polar organic solvent is sprayed onto the substrate, the temperature of the polar organic solvent is not less than the melting point of the normally used polar organic solvent, preferably 0 ° C. or more, and not more than the boiling point of the commonly used polar organic solvent, preferably 200 ° C. or less. . If the upper limit is exceeded, the bank-forming composition may be decomposed or dissolved, or the injected polar organic solvent may evaporate and a sufficient amount may not reach the substrate. In addition, the solubility of the residue of the bank-forming composition is lowered, and there is a possibility that defects due to moisture solidification may occur or the effects of the present invention may not be obtained.

The spraying time is usually 0.5 seconds or longer, preferably 1 second or longer, and usually 5 minutes or shorter, preferably 3 minutes or shorter. If the upper limit is exceeded, the organic layer on the electrode may be deteriorated or the bank portion may be deteriorated. If the lower limit is not reached, the residue may not be sufficiently removed and the effects of the present invention may not be obtained. .
The injection pressure is usually at least atmospheric pressure, preferably at least 0.11 MPa, and usually at most 2 MPa, preferably at most 1 MPa when the polar organic solvent is injected by pressurizing the chemical tank. If the upper limit is exceeded, the injection pressure is too strong and the bank may be peeled off or deformed. If the lower limit is exceeded, the polar organic solvent may not be injected.

  Since the required amount of liquid varies depending on the size of the substrate, it is necessary to prepare it appropriately. For example, when processing a 10 cm × 10 cm substrate, it is usually 10 ml / min or more. It is preferably 50 ml / min or more, and usually 10,000 ml / min or less, preferably 5000 ml / min or less. If this upper limit is exceeded, the cost may increase due to the use of more polar organic solvent than necessary, and if the lower limit is not reached, the required amount of polar organic solvent is not supplied and the removal of the residue is insufficient. Thus, the effects of the present invention may not be obtained.

After washing with the polar organic solvent, the purpose of removing the polar organic solvent adhering to the first organic layer and the bank, and that the components contained in the polar organic solvent adhere and remain in the first organic layer or the bank. A rinse treatment may be performed for the purpose of prevention. When performing the rinsing process, it is performed by a method of immersing in a rinsing liquid or pouring the rinsing liquid in a rod shape or shower shape on a substrate. The rinsing liquid is appropriately selected depending on the type of the solvent used in the polar organic solvent washing, but is preferably one that dissolves the solvent used in the polar organic solvent washing well.

For example, when a solvent that is dissolved in water, for example, methanol, ethanol, 1-propanol, 2-propanol, tetrahydrofuran, or the like is used as a solvent used in the polar organic solvent washing, ultrapure water can be used as the rinsing liquid.
In addition, when a solvent that is difficult to dissolve in water is used as the solvent used in the polar organic solvent washing, a nonpolar organic solvent can be used as the rinse liquid.

Examples of the nonpolar organic solvent include aliphatic hydrocarbon solvents such as hexane and cyclohexane, and aromatic hydrocarbon solvents such as toluene and xylene.
The number of polar organic solvent washing steps is not particularly limited as long as the effects of the present invention are not impaired, and may be included any number of times, but is usually 5 times or less, preferably 3 times or less, and usually 1 time or more.
In addition, when the process wash | cleaned with a polar organic solvent is included twice or more, you may perform this process with a respectively different solvent.

Further, at the end of the polar organic solvent cleaning step, the polar organic solvent or the rinsing liquid adhering to the rinsing process and the substrate is removed in the same manner as the rinsing process and the removal of the developing solution or the rinsing liquid adhering to the substrate. Also good.
(3-6. Heating step)
The manufacturing method of the organic electroluminescent element of this invention has a heating process after the image development process in the process of forming a bank. In particular, in the first aspect of the present invention, a heating step is provided after the polar organic solvent washing step.

The heating step is for the purpose of accelerating the crosslinking reaction of the photoresist, the purpose of improving the adhesion between the bank formed in a desired shape and the base, and the purpose of removing the rinsing liquid and undesirable impurities contained in the rinsing liquid by heating. Done for.
The heating conditions in the heating step are also appropriately selected depending on the type of the photoresist. The heating temperature is usually 80 ° C. or higher, preferably 100 ° C. or higher, and usually lower than 350 ° C., preferably lower than 300 ° C. If the lower limit value is not reached, the photoresist may not sufficiently undergo a crosslinking reaction, and if the upper limit value is exceeded, structural changes or chemical changes may occur in the bank and the first organic layer.

Although there is no restriction | limiting in particular about a heating means, Active energy ray irradiation, such as a hotplate, oven, infrared rays, and electromagnetic waves, etc. are mentioned.
The atmosphere during heating may be performed in the air, or in order to prevent moisture from being re-adsorbed after the heating process, or to oxidize the bank or the substrate at high temperature, in dry air having a dew point of 0 ° C. or lower, nitrogen, etc. The inert gas may be used at a pressure of 100 Pa or less.

Although there is no restriction | limiting in particular about the heating time in a heating process, From an industrial viewpoint, it is usually within 3 hours, Preferably it is performed within 1 hour.
On the other hand, when the same material as the first organic layer is used for the formation of the bank, the formation of the bank may be performed by exposure / development after the layer formation, as in the case of using the photoresist. It may be a method of exposing and developing so as to have a concave cross-sectional shape using a halftone mask or the like, or a method of applying the above material only to a region where a bank is formed by a wet film forming method or the like It may be.

The bank may be a single layer or two or more layers.
When the bank has two or more layers, it may be formed using the same type of bank forming composition, or may be formed using two different types of bank forming compositions. Further, two or more banks may be formed of different bank forming compositions.
The surface of the bank may be subjected to a lyophilic treatment, a liquid repellency treatment, or the like as appropriate in accordance with, for example, the method of forming the second organic layer (for example, the light emitting layer) or the forming material.
There are no particular restrictions on the method of lyophilic treatment or lyophobic treatment, but examples include fluorinated products such as CF ₄ , rare gases such as oxygen and argon, or mixed gas atmospheres under atmospheric pressure or reduced pressure conditions. A plasma discharge method, a method using a lyophilic or lyophobic material for the bank forming composition as described in the above section (2. Photoresist), or a bank forming composition. Examples thereof include a method of mixing a liquid or liquid repellent additive such as a surfactant.

(3-7. Bank physical properties)
(3-7-1. Film thickness)
The film thickness of the bank is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 10 nm or more, preferably 100 nm or more, and usually 100 μm or less, preferably 10 μm or less.
It is preferable for it to be in the above-mentioned range since film thickness unevenness of the second organic layer and the layer formed on the second organic layer can be suppressed.
In particular, when the second organic layer is a light emitting layer, the bank thickness is preferably larger than the light emitting layer thickness.

(3-7-2. Bank width)
The width of the bank is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 μm or more, preferably 10 μm or more in terms of the resolution of the photoresist and the adhesion between the first organic layer and the bank. .
Moreover, since the area | region in which the said bank was provided is used as the non-light-emitting area | region of an organic electroluminescent element, it is usually 500 micrometers or less, Preferably it is 100 micrometers or less from surfaces, such as the luminous efficiency of an organic electroluminescent element, and a light emission area.

(3-7-3. Film thickness difference before and after the polar organic solvent washing step)
The difference in bank film thickness before and after the polar organic solvent washing step is usually 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less. If the film thickness difference before and after cleaning is large, the film thickness tends to be non-uniform, and there is a risk of uneven light emission in the resulting device.

(4. Undercoat layer)
In the present invention, an undercoat layer may be provided on the first organic layer using a hydrophilic compound-containing composition containing a hydrophilic compound.
In the present invention, when the bank-forming composition is applied onto the first organic layer, and the bank is formed by exposure, development and heating, the bank-forming composition remains in the region partitioned by the bank. It is important that it is difficult to remain as. Therefore, when using a bank forming composition that has a strong affinity with the first organic layer and is likely to leave a residue, it is preferable to provide an undercoat layer.

In the present invention, the undercoat layer is formed by applying and drying a hydrophilic compound-containing composition on the first organic layer.
(4-1. Composition containing hydrophilic compound)
The hydrophilic compound-containing composition used for forming the undercoat layer contains a hydrophilic compound and usually further contains a solvent.

In the present invention, the hydrophilic compound is a compound that dissolves or swells in water. Here, dissolving in water means a compound having a solubility in water of usually 5% by weight or more, preferably 10% by weight or more, more preferably 20% by weight at 25 ° C. Within the above range, a film as the undercoat layer can be formed satisfactorily.
For the hydrophilic compound, more specifically, in the molecule, a functional group such as a carboxy group, a hydroxyl group, a sulfonic acid (salt) group, a phosphonic acid (salt) group, an amino group, an amide group, or a quaternary ammonium base. It is preferable that it is a compound which has this. In particular, the hydrophilic compound is preferably an organic compound.

  The hydrophilic compound is not particularly limited as long as it satisfies the above-mentioned conditions and can form a film. However, the hydrophilic compound is not limited to the film-forming property or the photosensitive composition when the bank-forming composition is a photoresist as described above. In order to ensure resistance, the hydrophilic compound is preferably a hydrophilic resin. Here, the hydrophilic resin is a resin having the above functional group, and usually refers to a resin obtained by polymerizing or condensing a unit (monomer or polymer) containing the above functional group. Moreover, the polymer material whose weight average molecular weight (Mw) measured by GPC (gel permeation chromatography) normally is about 1000-2,000,000 is said.

(4-1-1. Hydrophilic resin)
Examples of the hydrophilic resin that can be used as the hydrophilic compound include polyvinyl alcohol, polysaccharide, polyvinyl pyrrolidone, polyethylene glycol, gelatin, glue, casein, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, hydroxyethyl starch, sucrose octaacetate, and alginic acid. Ammonium, sodium alginate, polyvinylamine, polyarylamine, polystyrene sulfonic acid, polyacrylic acid, water-soluble polyamide, maleic anhydride copolymer, gum arabic, water-soluble soybean polysaccharide, white dextrin, pullulan, curdlan, chitosan, In addition to alginic acid, enzyme-decomposed etherified dextrin, and the like, (co) polymer (co) polymerized using a hydrophilic monomer and the like can be mentioned.

(4-1-2. Hydrophilic monomer)
Examples of hydrophilic monomers include (meth) acrylic acid or its alkali metal salts and amine salts, itaconic acid or its alkali metal salts and amine salts, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-monomethylol ( (Meth) acrylamide, N-dimethylol (meth) acrylamide, arylamine or its hydrohalide, 3-vinylpropionic acid or its alkali metal salt and amine salt, vinylsulfonic acid or its alkali metal salt and amine salt, vinylpyrrolidone , 2-sulfoethyl (meth) acrylate, polyoxyethylene glycol mono (meth) acrylate, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphooxypolyoxyethylene glycol mono ( Data), such as acrylate, a carboxyl group, a sulfo group, a phosphoric acid group, an amino group or a salt thereof, hydroxyl group and a monomer having a hydrophilic group selected from an amide group and an ether group.

(4-1-3. Hydrophilic compounds other than hydrophilic resins)
Moreover, what was illustrated as said hydrophilic monomer as hydrophilic compounds other than hydrophilic resin is mentioned, It is also preferable that these are contained with a monomer in a hydrophilic compound containing composition.
Examples of the hydrophilic compound include vinylpyrrolidone (co) polymers, (meth) acrylic acid (co) polymers, polyvinyl alcohol and derivatives thereof, and celluloses such as hydroxyethylcellulose, carboxymethylcellulose, and methylcellulose. A hydrophilic resin such as is preferable.

The hydrophilic compound-containing composition used in the present invention may contain one kind of these hydrophilic compounds or may contain two or more kinds.
The hydrophilic compound is preferably contained in the total solid content of the hydrophilic compound-containing composition in an amount of preferably 10% by weight or more, more preferably 20% by weight or more and 100% by weight or less. When the content of the hydrophilic compound in the hydrophilic compound-containing composition is less than the above lower limit, it becomes difficult to completely remove the formed undercoat layer by development, leading to white spots. In addition, it becomes difficult to form a uniform organic thin film in the region delimited by the bank by the ink ejection type coating method.

(4-1-4. Other components)
The hydrophilic compound-containing composition in the present invention may contain other components as necessary in addition to the hydrophilic compound. Other components include, for example, photopolymerization initiators, thermal polymerization initiators, ethylenically unsaturated compounds and other reactive compounds, surfactants, fillers, substrate adhesion enhancers, development accelerators such as acids and alcohols, colors Examples thereof include materials, thermal polymerization inhibitors, plasticizers, storage stabilizers, and surface protection agents. In particular, when the bank-forming composition is a photoresist, the composition is made photosensitive by adding a photopolymerization initiator or an ethylenically unsaturated compound to the hydrophilic compound-containing composition. Polymerization at the time of exposure together with the composition layer is also useful in terms of ensuring adhesion at each interface.

  Examples of the photopolymerization initiator and ethylenically unsaturated compound used in this case include those exemplified as the photopolymerization initiator and ethylenically unsaturated compound contained in the photosensitive composition described below. . When the hydrophilic compound-containing composition contains a photopolymerization initiator, the content is usually 0.01% by weight or more, usually 10% by weight or less, preferably 5% by weight in the total solid content of the composition. % Or less. When the hydrophilic compound-containing composition contains an ethylenically unsaturated compound, the content thereof is usually 1% by weight or more, preferably 3% by weight or more, and usually 80% by weight or less, preferably in the total solid content of the composition. Is 50% by weight or less. If the content of the photopolymerization initiator and the ethylenically unsaturated compound is too small, the photosensitivity due to the inclusion thereof cannot be obtained, and if too large, the content of the hydrophilic compound is relatively reduced, The above problem may occur.

  Here, the hydrophilic compound-containing composition does not need to be photosensitive, and it is sufficient to select a bank forming composition material and developer, and control the thickness of the undercoat layer. It is possible to ensure adhesion to the forming composition layer. Further, when the bank-forming composition is a photoresist, it is possible to devise measures such as avoiding bank tailing by utilizing the fact that the undercoat layer is not photosensitive.

(4-1-5. Solvent)
The solvent contained in the hydrophilic compound-containing composition is not particularly limited as long as the solid content of the hydrophilic compound-containing composition can be dissolved or dispersed and enables uniform coating. Is preferably dissolved rather than dispersed in this solvent. From the viewpoint of securing this solubility, it is preferable to use water and / or an alcohol solvent. The main component of the solvent contained in the hydrophilic compound-containing composition is preferable.

  Water and / or alcohol solvents are also preferable in that the organic layer is not dissolved, particularly when the undercoat layer is provided on the organic layer. In particular, the organic layer is a hole of the organic electroluminescent device. This is useful when it is an injection layer or a hole transport layer. Furthermore, after forming the undercoat layer, when applying the bank forming composition, the undercoat layer is prevented from flowing out by the organic solvent contained in the bank forming composition. The component is highly soluble in water and / or an alcohol solvent, and is preferably hardly soluble or insoluble in an organic solvent that is a solvent for the aforementioned bank forming composition.

Specific examples of the alcohol solvent used in the hydrophilic compound-containing composition include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, 1-butanol, 2
-Alkyl alcohols such as butanol, isobutyl alcohol, tert-butyl alcohol, glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, butylene glycol monomethyl ether 3-methyl-3-methoxybutanol, 3-methyl-3-ethoxybutanol, 3-methyl-3-n-propoxybutanol, 3-methyl-3-isopropoxybutanol, 3-methyl-3-n-butoxy Sibutanol, 3-methyl-3-isobutoxysibutanol, 3-methyl-3-sec-butoxybutanol, 3-methyl-3-tert-butoxy Ethanol, alkoxy alcohols such as 3-methoxy butanol.

  The alkyl group chain of the alcohol solvent is preferably not so long from the viewpoint of the solubility of the hydrophilic compound, and as the alkyl alcohol, those having an alkyl group with about 2 to 4 carbon atoms are preferable. Are preferably those in which the alkylene group of the alkylene glycol moiety has about 3 to 5 carbon atoms, and the alkoxy alcohols preferably have an alkoxy group having about 2 to 4 carbon atoms.

  The solvent for the hydrophilic compound-containing composition may be a solvent other than water or an alcohol solvent, and the solvent other than water or an alcohol solvent that can be used for the hydrophilic compound-containing composition is dioxane. , Tetrahydrofuran, 1,2-diethoxyethane, 1,2-dimethoxyethane, 1,2-dibutoxyethane and other ethers, acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone and other ketones, 3-methoxybutyl Examples thereof include esters such as acetate, butyl diglycol acetate, ethyl diglycol acetate, and propylene glycol monomethyl ether acetate. These may be used alone or mixed with water or an alcohol solvent.

The solvent contained in the hydrophilic compound-containing composition may be only one selected from water, the above-mentioned alcohol solvents, and other solvents, or may be a mixed solvent of two or more.
However, the solvent in the hydrophilic compound-containing composition is preferably composed of water and / or an alcohol solvent, and other solvents can be mixed and used. The solvent is preferably contained in an amount of 5% by weight or more, particularly 20% by weight or more and 100% by weight or less. In particular, the water and / or alcohol solvent is preferably contained as a main component of the solvent of the hydrophilic compound-containing composition. “To be contained as a main component of the solvent” means that water, an alcohol-based solvent, or a mixed solvent of water and an alcohol-based solvent is contained in the largest amount in the solvent.

The total solid concentration in the hydrophilic compound-containing composition is preferably 0.1% by weight or more, more preferably 0.2% by weight or more, preferably 10% by weight or less, more preferably 5% by weight or less. is there. When the total solid content concentration of the hydrophilic compound-containing composition is below the lower limit, it is difficult to form a coating film, and when it exceeds the upper limit, it may be difficult to form a thin film.
(4-2. Method for Forming a Hydrophilic Compound-Containing Composition)
A coating method for forming the undercoat layer by coating and drying the hydrophilic compound-containing composition directly or on another layer on the substrate is not limited. For example, spin coating method, wire bar method It can be applied by a flow coating method, a die coating method, a roll coating method, a spray coating method, a dip coating method or the like. These coating methods can be freely selected depending on the film thickness.

As a drying method, a method of drying using a hot plate, an IR oven, or a convection oven is preferable. Drying conditions can be appropriately selected according to the type of the solvent component, the performance of the dryer used, and the like. The drying temperature is usually 40 ° C. or higher, preferably 50 ° C. or higher, usually 200 ° C. or lower, preferably 130 ° C. or lower. Further, the drying time is preferably 15 seconds or more, preferably 30 seconds or more, preferably 5 minutes or less, and preferably 3 minutes or less. If the drying temperature is too low or the drying time is short, it may not be sufficiently dried and may flow out when the photosensitive composition is applied. The drying temperature is too high or the drying time is too long. In addition, there is a problem of productivity reduction and thermal deterioration of the substrate and other layers, which is not preferable.

The drying may be a reduced pressure drying method in which the temperature is not increased and drying is performed in a reduced pressure chamber, or a combination of reduced pressure drying and heat drying may be used.
The thickness of the undercoat layer obtained after drying is not particularly limited, but is preferably 1/3 or less of the completed bank height including the undercoat layer, more preferably 1/4 or less, and 1 / 200 or more is preferable, and 1/50 or more is more preferable. When the thickness of the undercoat layer becomes thicker than this, there are the following problems. That is, since the undercoat layer has higher wettability with respect to the ink for forming the organic thin film than the portion of the bank resist layer, when forming the organic thin film, the organic thin film is exposed at the exposed portion of the undercoat layer on the bank wall surface. The coating thickness becomes high, and the film is dried in this state, and after drying, a non-uniform organic thin film is formed in which the central part of the area partitioned by the bank is thin and the periphery is thick. There is a risk. On the contrary, if the thickness of the undercoat layer is smaller than the lower limit, it is difficult to obtain the effect of the present invention due to the formation of the undercoat layer.

  The specific thickness of the undercoat layer is preferably 5 nm or more, more preferably 7 nm or more, particularly preferably 10 nm or more, preferably 4 μm or less, more preferably 1 μm or less, and particularly preferably 0.5 μm or less. If the film thickness of the undercoat layer is less than this lower limit, the effect of the undercoat layer is difficult to obtain, and if it exceeds the upper limit, the organic thin film is difficult to be uniformly formed in the region partitioned by the bank as described above. Further, when the undercoat layer is not photosensitive, it is difficult to hold the upper bank-forming composition layer.

[Surface roughness]
In the present invention, the Ra (arithmetic mean roughness) of the surface of the first organic layer in the region partitioned by the bank after forming the bank is 1.0 nm or less and / or the maximum height (maximum height difference). Value) is preferably 10 nm or less. Here, Ra (arithmetic mean roughness) and maximum height (maximum height difference) are calculated by the method described in JIS B 0601.

  Ra of the surface of the first organic layer in the region partitioned by the bank after forming the bank is preferably 1.0 nm or less, more preferably 0.5 nm or less, and the maximum height is preferably 10 nm. Hereinafter, it is more preferably 5 nm or less. If either one of Ra and the maximum height exceeds the upper limit, it is difficult to form the second organic layer with a uniform film thickness, and uneven light emission of the organic electroluminescence element is likely to occur or short-circuiting easily occurs. In addition, if either Ra or the maximum height exceeds the upper limit, there may be a residue, or the first organic layer may be altered and raised, so that the voltage of the organic electroluminescent device increases, light emission In some cases, efficiency and service life may decrease.

[Second organic layer]
The organic electroluminescent element of the present invention has a second organic layer on the first organic layer in which the bank is formed. The second organic layer in the present invention is preferably a light emitting layer.
In the present invention, the second organic layer is formed only in a region partitioned by the bank in the first organic layer, that is, only in a region where the bank is not formed and the first organic layer is exposed. Alternatively, the second organic layer may be formed on the area partitioned by the bank and the bank.

  Specifically, the second organic layer is formed by the above-mentioned bank by a wet film formation method represented by an inkjet method, a nozzle printing method, a screen printing method, an offset printing method, an aerosol method, an aerosol jet method, or the like. A method of forming a second organic layer by forming a film using the second organic layer composition for forming the second organic layer only in the partitioned region may be used. A method of forming a second organic layer by forming a film so as to cover the organic layer and the bank by a vacuum deposition method, a wet film formation method, or the like may be used.

Further, after forming a film so as to cover the organic layer and the bank, this layer may be patterned to form the second organic layer only in a necessary region. In addition, you may form several types of 2nd organic layer using a different material for every area | region divided by the bank.
Preferably, the film is formed in a region partitioned by the bank by an inkjet method.
In addition, about the formation method of the 2nd organic layer in this process, and the film thickness, shape, etc. of the 2nd organic layer to form, it selects suitably according to the kind etc. of the 2nd organic layer to form.

In the organic electroluminescent element of the present invention, the light emitting layer is preferably used as the second organic layer and provided in the region partitioned by the bank, but other layers may be used as the second organic layer.
Moreover, in this invention, you may have another process suitably before and after each said process and between each process as needed.

Hereinafter, a light emitting layer suitable as the second organic layer will be described.
In the organic electroluminescent device produced by the production method of the present invention, it is preferable that a light emitting layer is provided on a hole transport layer in at least a region partitioned by the bank, that is, a region where no bank is formed. In particular, by forming red, green, and blue light-emitting layers in the areas partitioned by each bank, it is possible to paint each color separately.
The light-emitting layer is a layer that is excited by recombination of holes injected from the anode through a hole injection layer or the like and electrons injected from the cathode between electrodes to which an electric field is applied, and becomes a main light-emitting source. is there.

(Light emitting layer material)
The light emitting layer contains at least a material having a light emitting property (light emitting material) as a constituent material, and preferably a compound having a hole transporting property (hole transporting compound) or an electron transporting material. Contains a compound having properties (electron transporting compound). A light emitting material may be used as a dopant material, and a hole transporting compound, an electron transporting compound, or the like may be used as a host material. There is no particular limitation on the light-emitting material, and a material that emits light at a desired light emission wavelength and has favorable light emission efficiency may be used. Furthermore, the light emitting layer may contain other components as long as the effects of the present invention are not significantly impaired. In addition, when forming a light emitting layer with a wet film-forming method, it is preferable to use a low molecular weight material in any case.

(Luminescent material)
Any known material can be applied as the light emitting material. For example, a fluorescent material or a phosphorescent material may be used, but a phosphorescent material is preferable from the viewpoint of internal quantum efficiency. Alternatively, blue may be used in combination, such as using a fluorescent material, and green and red using a phosphorescent material.

For the purpose of improving the solubility in a solvent, it is preferable to reduce the symmetry and rigidity of the molecules of the luminescent material or to introduce a lipophilic substituent such as an alkyl group.
Hereinafter, examples of the fluorescent light emitting material among the light emitting materials will be given, but the fluorescent dye is not limited to the following examples.
Examples of fluorescent light emitting materials (blue fluorescent dyes) that emit blue light include naphthalene, perylene, chrysene, pyrene, anthracene, coumarin, and p-bis (2-phenylethenyl).
Examples thereof include benzene and derivatives thereof.

Examples of the fluorescent light emitting material (green fluorescent dye) that gives green light emission include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al (C ₉ H ₆ NO) ₃ .
Examples of the fluorescent light emitting material (yellow fluorescent dye) that gives yellow light include rubrene, perimidone derivatives, and the like.

Examples of the fluorescent light-emitting material (red fluorescent dye) that emits red light include, for example, DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran) -based compounds, benzopyran derivatives, rhodamine derivatives, Examples thereof include benzothioxanthene derivatives and azabenzothioxanthene.
As the phosphorescent material, for example, a long-period type periodic table (hereinafter referred to as a long-period type periodic table when referred to as “periodic table” unless otherwise specified) is selected from the seventh to eleventh groups. And an organometallic complex containing a metal.

Preferred examples of the metal selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.
The ligand of the complex is preferably a ligand in which a (hetero) aryl group such as a (hetero) arylpyridine ligand or (hetero) arylpyrazole ligand is linked to pyridine, pyrazole, phenanthroline, etc. A pyridine ligand and a phenylpyrazole ligand are preferable. Here, (hetero) aryl represents an aryl group or a heteroaryl group.

  Specific examples of the phosphorescent material include tris (2-phenylpyridine) iridium, tris (2-phenylpyridine) ruthenium, tris (2-phenylpyridine) palladium, bis (2-phenylpyridine) platinum, tris (2- Phenylpyridine) osmium, tris (2-phenylpyridine) rhenium, octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl palladium porphyrin, octaphenyl palladium porphyrin, and the like.

  The molecular weight of the compound used as the light emitting material is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 10,000 or less, preferably 5000 or less, more preferably 4000 or less, still more preferably 3000 or less, and usually 100 or more, Preferably it is 200 or more, More preferably, it is 300 or more, More preferably, it is the range of 400 or more. If the molecular weight of the luminescent material is too small, the heat resistance will be significantly reduced, gas generation will be caused, the film quality will be reduced when the film is formed, or the morphology of the organic electroluminescent element will be changed due to migration, etc. Sometimes come. On the other hand, if the molecular weight of the luminescent material is too large, it tends to be difficult to purify the organic compound, or it may take time to dissolve in the solvent.

In addition, only 1 type may be used for the luminescent material mentioned above, and 2 or more types may be used together by arbitrary combinations and a ratio.
The ratio of the light emitting material in the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.05% by weight or more and usually 35% by weight or less. If the amount of the light emitting material is too small, uneven light emission may occur. If the amount is too large, the light emission efficiency may be reduced. In addition, when using together 2 or more types of luminescent material, it is made for the total content of these to be contained in the said range.

(Hole transporting compound)
The light emitting layer may contain a hole transporting compound as a constituent material. Here, among the hole transporting compounds, examples of the low molecular weight hole transporting compound include various compounds exemplified as (low molecular weight hole transporting compound) in the above-described hole injection layer, For example, two or more condensed aromatic rings including two or more tertiary amines represented by 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl are substituted with nitrogen atoms. Aromatic amine compounds having a starburst structure (Journal of Luminescence, 1997) such as aromatic diamines (Japanese Patent Laid-Open No. 5-234811), 4,4 ′, 4 ″ -tris (1-naphthylphenylamino) triphenylamine , Vol.72-74, pp.985), an aromatic amine compound comprising a tetramer of triphenylamine (Chemical Communica) ions, 1996, pp. 2175), spiro compounds such as 2,2 ′, 7,7′-tetrakis- (diphenylamino) -9,9′-spirobifluorene (Synthetic Metals, 1997, Vol. 91, pp. 209) and the like.

In the light emitting layer, only one type of hole transporting compound may be used, or two or more types may be used in any combination and ratio.
The ratio of the hole transporting compound in the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.1% by weight or more and usually 65% by weight or less. If the amount of the hole transporting compound is too small, it may be easily affected by a short circuit, and if it is too large, the film thickness may be uneven. In addition, when using together 2 or more types of hole transportable compounds, it is made for the total content of these to be contained in the said range.

(Electron transporting compound)
The light emitting layer may contain an electron transporting compound as a constituent material. Here, among the electron transporting compounds, examples of low molecular weight electron transporting compounds include 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (BND) and 2,5. -Bis (6 '-(2', 2 "-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), bathophenanthroline (BPhen), 2,9-dimethyl-4,7 -Diphenyl-1,10-phenanthroline (BCP, bathocuproin), 2- (4-biphenylyl) -5- (p-tertiarybutylphenyl) -1,3,4-oxadiazole (tBu-PBD), 4 , 4′-bis (9-carbazole) -biphenyl (CBP), etc. In the light emitting layer, only one type of electron transporting compound may be used, or two or more types may be combined in any combination. And it may be used in combination in the ratio.

  The ratio of the electron transporting compound in the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.1% by weight or more and usually 65% by weight or less. If the amount of the electron transporting compound is too small, it may be easily affected by a short circuit, and if it is too large, the film thickness may be uneven. In addition, when using together 2 or more types of electron transport compounds, it is made for the total content of these to be contained in the said range.

(Formation of light emitting layer)
In the case of forming a light emitting layer, the above material is dissolved in an appropriate solvent to prepare a composition for forming a light emitting layer, and a film is formed using the composition. As the light emitting layer solvent to be contained in the light emitting layer forming composition, any solvent can be used as long as the light emitting layer can be formed. Suitable examples of the solvent for the light emitting layer are the same as those described for the composition for forming a hole injection layer.

The ratio of the light-emitting layer solvent to the light-emitting layer-forming composition for forming the light-emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.01% by weight or more, usually 70% by weight or less, It is. In addition, when using 2 or more types of solvents as a solvent for light emitting layers, it is made for the sum total of these solvents to satisfy | fill this range.
The solid content concentration of the light emitting material, hole transporting compound, electron transporting compound and the like in the composition for forming a light emitting layer is usually 0.01% by weight or more and usually 70% by weight or less. If this concentration is too large, film thickness unevenness may occur, and if it is too small, defects may occur in the film.

After wet forming the composition for forming a light emitting layer, the obtained coating film is dried and the solvent is removed to form a light emitting layer. Specifically, it is the same as the method described in the formation of the hole injection layer. The method of the wet film forming method is not limited as long as the effect of the present invention is not significantly impaired, and any of the methods described above can be used.
The thickness of the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 3 nm or more, preferably 5 nm or more, and usually 200 nm or less, preferably 100 nm or less. If the light emitting layer is too thin, defects may occur in the film, and if it is too thick, the driving voltage may increase.

(Electron transport layer)
An electron transport layer may be provided on the light emitting layer.
The electron transport layer is provided for the purpose of further improving the light emission efficiency of the device, and can efficiently transport electrons injected from the cathode between the electrodes to which an electric field is applied in the direction of the light emitting layer. Is formed.

  The electron transporting compound used for the electron transporting layer is usually a compound that has high electron injection efficiency from the cathode or the electron injection layer and has high electron mobility and can efficiently transport the injected electrons. Is used. Examples of the compound satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo [h] quinoline, oxadiazole derivatives , Distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline compounds ( JP-A-6-207169), phenanthroline derivative (JP-A-5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthraquinonediimine, n-type hydrogenated amorphous silicon carbide , N-type zinc sulfide, n-type zinc Such as emissions of zinc, and the like.

In addition, only 1 type may be used for the material of an electron carrying layer, and 2 or more types may be used together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of an electron carrying layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods. The electron transport layer may be formed only in a region partitioned by the bank, but is preferably formed on the entire surface.
The thickness of the electron transport layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

(Electron injection layer)
The electron injection layer plays a role of efficiently injecting electrons injected from the cathode into the light emitting layer. In order to perform electron injection efficiently, the material for forming the electron injection layer is preferably a metal having a low work function. Examples include alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the film thickness is preferably from 0.1 nm to 5 nm.

Further, an organic electron transport compound represented by a metal complex such as a nitrogen-containing heterocyclic compound such as bathophenanthroline or an aluminum complex of 8-hydroxyquinoline is doped with an alkali metal such as sodium, potassium, cesium, lithium or rubidium. (Described in JP-A-10-270171, JP-A-2002-1000047, JP-A-2002-1000048, etc.) makes it possible to improve electron injection / transport properties and achieve excellent film quality. Therefore, it is preferable. In this case, the film thickness is usually 5 nm or more, preferably 10 nm or more, and is usually 200 nm or less, preferably 100 nm or less.

In addition, only 1 type may be used for the material of an electron injection layer, and 2 or more types may be used together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of an electron injection layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods. The electron injection layer may be formed only in a region partitioned by the bank, but is preferably formed on the entire surface.

(cathode)
The cathode plays a role of injecting electrons into a layer (such as an electron injection layer or a light emitting layer) on the light emitting layer side.
As the material of the cathode, it is possible to use the material used for the anode, but in order to perform electron injection efficiently, a metal having a low work function is preferable, for example, tin, magnesium, indium, calcium, A suitable metal such as aluminum or silver or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

In addition, only 1 type may be used for the material of a cathode, and 2 or more types may be used together by arbitrary combinations and a ratio.
The thickness of the cathode is usually the same as that of the anode. The cathode may be formed only in the area partitioned by the bank, but is preferably formed on the entire surface.
Further, for the purpose of protecting the cathode made of a low work function metal, it is preferable to further stack a metal layer having a high work function and stable to the atmosphere because the stability of the device is increased. For this purpose, for example, metals such as aluminum, silver, copper, nickel, chromium, gold and platinum are used. In addition, these materials may be used only by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Other layers)
The organic electroluminescent element according to the present invention may have another configuration without departing from the gist thereof. For example, as long as the performance is not impaired, an arbitrary layer may be provided between the anode and the cathode in addition to the layers described above, and an arbitrary layer may be omitted.
(Hole blocking layer)
A hole blocking layer may be provided between the light emitting layer and the electron injection layer. The hole blocking layer is a layer stacked on the light emitting layer so as to be in contact with the cathode side interface of the light emitting layer.

The hole blocking layer has a role of blocking holes moving from the anode from reaching the cathode and a role of efficiently transporting electrons injected from the cathode toward the light emitting layer.
The physical properties required for the material constituting the hole blocking layer include high electron mobility, low hole mobility, large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). It is expensive. Examples of the material for the hole blocking layer satisfying such conditions include bis (2-methyl-8-quinolinolato) (phenolato) aluminum, bis (2-methyl-8-quinolinolato) (triphenylsilanolato) aluminum, and the like. Mixed metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolinato) aluminum binuclear metal complexes, distyrylbiphenyl derivatives, etc. Triazole derivatives such as styryl compounds (JP-A-11-242996), 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole (JP-A-7 -41759), phenanthroline derivatives such as bathocuproine (JP-A-10-79297), and the like. That. Further, a compound having at least one pyridine ring substituted at the 2,4,6-positions described in International Publication No. 2005-022962 is also preferable as a material for the hole blocking layer.

In addition, the material of a hole-blocking layer may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of a hole-blocking layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods. The hole blocking layer may be formed only in a region partitioned by the bank, but is preferably formed on the entire surface.

The thickness of the hole blocking layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.
(Hole relaxation layer)
The hole relaxation layer is a layer formed adjacent to the cathode side of the light emitting layer, and is a layer that functions to relax the accumulation of holes at the interface between the light emitting layer and the hole relaxation layer. It also has a role of efficiently transporting electrons toward the light emitting layer. For the hole relaxation layer, an electron transport compound (hole relaxation material) having a hole transport unit is used.
(Electron blocking layer)
Further, an electron blocking layer may be provided between the hole injection layer or the hole transport layer and the light emitting layer.

  The electron blocking layer prevents electrons moving from the light emitting layer from reaching the hole injection layer, thereby increasing the recombination probability of holes and electrons in the light emitting layer and emitting the generated excitons. There are a role of confining in the layer and a role of efficiently transporting holes injected from the hole injection layer toward the light emitting layer. In particular, when a phosphorescent material or a blue light emitting material is used as the light emitting material, it is effective to provide an electron blocking layer.

  The characteristics required for the electron blocking layer include high hole transportability, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1). Furthermore, in the present invention, when the light emitting layer is produced by a wet film formation method, the electron blocking layer is also required to be compatible with the wet film formation. Examples of the material used for such an electron blocking layer include a copolymer of dioctylfluorene and triphenylamine typified by F8-TFB (International Publication No. 2004/084260).

In addition, the material of an electron blocking layer may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of an electron blocking layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods. The electron blocking layer may be formed only in a region partitioned by the bank, but is preferably formed on the entire surface.

Further, at the interface between the cathode and the light emitting layer or the electron transport layer, for example, lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), lithium oxide (Li ₂ O), cesium carbonate (II) (CsCO ₃ ), etc. are formed. It is also an effective method to improve the efficiency of the device by inserting a very thin insulating film (0.1 to 5 nm) (Applied Physics Letters, 1997, Vol. 70, pp. 152; No. 74586; IEEE Transactions on Electron Devices, 1997, Vol. 44, pp. 1245; SID 04 Digest, pp. 154, etc.).

Moreover, in the layer structure demonstrated above, it is also possible to laminate | stack components other than a board | substrate in reverse order. For example, in the case of the layer configuration of FIG. 1, the other components on the substrate are in the order of cathode, electron injection layer, electron transport layer, hole blocking layer, light emitting layer, hole transport layer, hole injection layer, and anode. It may be provided. In addition to the hole transport layer, the first organic layer may be a hole injection layer, or may be another layer.

Furthermore, it is also possible to constitute the organic electroluminescent element according to the present invention by laminating components other than the substrate between two substrates, at least one of which is transparent.
Further, a structure in which a plurality of components (light emitting units) other than the substrate are stacked in a plurality of layers (a structure in which a plurality of light emitting units are stacked) may be employed. In that case, instead of the interface layer between the steps (between the light emitting units) (when the anode is ITO and the cathode is Al, these two layers), for example, a charge made of vanadium pentoxide (V ₂ O ₅ ) or the like. When a generation layer (Carrier Generation Layer: CGL) is provided, a barrier between steps is reduced, which is more preferable from the viewpoint of light emission efficiency and driving voltage.

Furthermore, the organic electroluminescent device according to the present invention may be configured as a single organic electroluminescent device, or may be applied to a configuration in which a plurality of organic electroluminescent devices are arranged in an array. You may apply to the structure by which the cathode is arrange | positioned at XY matrix form.
Each layer described above may contain components other than those described as materials unless the effects of the present invention are significantly impaired.

<Organic EL display>
The organic EL display of the present invention uses the organic electroluminescent element of the present invention as described above. There is no restriction | limiting in particular about the model and structure of the organic electroluminescent display of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.
For example, the organic EL display of the present invention is formed by a method as described in “Organic EL display” (Ohm, published on August 20, 2004, Shizushi Tokito, Chiba Adachi, Hideyuki Murata). can do.

<Organic EL lighting>
The organic EL illumination of the present invention uses the above-described organic electroluminescent element of the present invention. There is no restriction | limiting in particular about the model and structure of the organic EL illumination of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The following examples are given for the purpose of illustrating the present invention in detail, and the present invention is not limited to the following examples unless it is contrary to the spirit thereof.
In the step of forming a bank with a photoresist on the hole transport layer as the first organic layer, in order to evaluate the influence on the organic electroluminescence device due to the residue of the bank forming composition, that is, the resist residue, Thus, it is simple and effective to perform resist evaluation on the surface of the hole transport layer and evaluate it. That is, a photoresist (bank forming composition) is wet-formed on the entire surface of the hole transport layer as the first organic layer, and the process proceeds to the development process without performing the mask exposure process, and the film is formed with the developer. The entire photoresist is removed, washed with a polar organic solvent according to the purpose, and then baked. As a result, no bank is formed, but the surface of the hole transport layer is the same surface as the opening of the bank.

  In this way, by subjecting the surface of the hole transport layer to a resist treatment to produce and evaluate an organic electroluminescent device, the influence of the resist residue on the organic electroluminescent device can be easily evaluated.

[Description 1]
First, in the resist processing, polar organic solvent cleaning was performed between the development step and the heating step.
In Examples 1-2 and Comparative Examples 1-3, the hole transport layer as the first organic layer was subjected to resist treatment, and an organic electroluminescence device was produced and evaluated.
[Example 1]
(Formation of anode)
First, an indium tin oxide (ITO) transparent conductive film deposited on a glass substrate with a thickness of 120 nm (manufactured by Sanyo Vacuum Co., Ltd., sputtered film) is obtained using ordinary photolithography technology and hydrochloric acid etching. An anode was formed by patterning into a stripe having a width of 2 mm. The patterned ITO substrate is cleaned in the order of ultrasonic cleaning with an aqueous surfactant solution, water cleaning with ultrapure water, ultrasonic cleaning with ultrapure water, and water cleaning with ultrapure water, followed by drying with nitrogen blow, and finally UV irradiation. Ozone cleaning was performed.

(Formation of hole injection layer)
Next, a composition for forming a hole injection layer was prepared. 2% by weight of a polymer having a repeating structure of the following formula (i) (weight average molecular mass 29600; glass transition temperature 177 ° C.) and 0.8% by weight of an electron-accepting compound represented by the following formula (ii) are used as a solvent. Was dissolved in ethyl benzoate to prepare a hole injection layer forming composition (A1).

  A hole injection layer was formed on the cleaned ITO substrate by spin coating using the composition for hole injection layer (A1). The spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, the spin rotation speed was 1500 rpm, and the spin time was 30 seconds. After coating, the substrate was heated and dried on a hot plate at 80 ° C. for 1 minute, and then baked in an oven atmosphere at 230 ° C. for 1 hour to form a hole injection layer having a thickness of 30 nm.

(Formation of hole transport layer)
Next, a composition for forming a hole transport layer was prepared. 0.4% by weight of a polymer having a repeating structure of the following formula (iii) (weight average molecular mass 10,000; glass transition temperature 138 ° C.) was dissolved in toluene as a solvent to prepare a composition for a hole transport layer. As the toluene, commercially available dehydrated toluene was used, and a hole transport layer forming composition (B1) was prepared in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm.

  The substrate coated with the hole injection layer was placed in a nitrogen glove box, and a hole transport layer was formed on the hole injection layer by the spin coating method using the composition for forming a hole transport layer (B1). The spin rotation speed was 1500 rpm and the spin time was 30 seconds. After coating, baking was performed on a hot plate at 230 ° C. for 1 hour to form a 20 nm-thick hole transport layer.

Preparation of the composition for forming a hole transport layer, spin coating and baking were all carried out in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm without being exposed to the atmosphere.
(Preparation of bank forming composition)
Next, a bank forming composition (C1) was prepared.
Binder resin: 72 parts by weight of a polymer having a repeating structure of the following formula (iv) (weight average molecular weight 4000),
Ethylenically unsaturated compound: 24 parts by weight of a compound having the structure of the following formula (v):
Photopolymerization initiator: 4 parts by weight of a compound having the structure of the following formula (vi)
Photopolymerization initiator: 1.5 parts by weight of a compound having the structure of the following formula (vii)
Surfactant: 0.1 part by weight of MegaFuck F475 (Dainippon Ink Chemical Co., Ltd.)
It melt | dissolved in propylene glycol monomethyl ether acetate (PGMEA) as a solvent, and prepared the composition (C1) for bank formation with a solid content concentration of 25 weight%.

(Preparation of a hole transport layer treated with a bank forming composition)
Next, the substrate on which the hole injection layer and the hole transport layer are laminated in this order is taken out into the atmosphere, and the prepared bank forming composition (C1) is used in a yellow room where ultraviolet light is cut. The surface of the hole transport layer was treated by the following procedure.

(Coating process / Pre-baking process)
First, the bank forming composition (C1) was applied onto the hole transport layer by spin coating. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. As the spin condition, after rotating at 300 rpm for 2 seconds, it was continuously rotated at 1200 rpm for 3 seconds. After the application, it was heated and dried (prebaked) at 90 ° C. for 60 seconds on a hot plate.

(Development process)
Next, it was immersed in a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) for 120 seconds, and then washed with pure water for 120 seconds and blown with nitrogen to dry. As a result, the entire layer formed using the bank forming composition was removed.
(Polar organic solvent washing process)
Next, it was immersed for 60 seconds at 23 ° C. using ethanol as a polar organic solvent. After that, pure water was run for 10 seconds as a rinsing treatment, and dried by blowing nitrogen.

(Heating process)
Finally, the substrate after the polar organic solvent cleaning step was heated on a hot plate at 230 ° C. for 30 minutes.
This substrate was placed in a chamber of a vacuum deposition apparatus. The chamber was roughed with a rotary pump and then depressurized with a cryopump. The degree of vacuum was 1.0 × 10 ⁻⁴ Pa. A vapor deposition mask was arranged in a predetermined area on the substrate, and necessary vapor deposition materials were individually placed in advance in the chamber in crucibles wound with heater wires.

(Formation of light emitting layer)
Each of 4,4′-bis (9-carbazole) -biphenyl (CBP) represented by the following formula (viii) as a host material and Ir (ppy) ₃ represented by the following formula (ix) as a dopant The crucible was simultaneously heated with a heater wire and co-deposited on the hole transport layer. Deposition conditions are as follows: the degree of vacuum at the time of vapor deposition is 1.0 × 10 ⁻⁴ Pa, the deposition rate of CBP is 0.6 Ｉ / s, the deposition rate of Ir (ppy) ₃ is 0.036 Å / s, and CBP: Ir (ppy) A light emitting layer having a thickness of 3 = 100: 6 and a thickness of 30 nm was formed.

(Formation of hole blocking layer)
A crucible containing BAlq represented by the following formula (x) was heated by energization with a heater wire and deposited on the light emitting layer. Deposition conditions were such that the degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa, the deposition rate was 1.0 Å / s, and the hole blocking layer was formed with a film thickness of 10 nm.

(Formation of electron transport layer)
A crucible containing Alq ₃ (aluminum complex of 8-hydroxyquinoline) was heated by energization with a heater wire and deposited on the hole blocking layer. Deposition conditions were such that the degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa, the deposition rate was 1.5 、 / s, and the electron transport layer was formed with a film thickness of 30 nm.

(Formation of electron injection layer)
Here, the element on which the vapor deposition has been performed is once taken out from the vacuum vapor deposition apparatus to the atmosphere, and a 2 mm wide stripe shadow mask is brought into close contact with the element so as to be orthogonal to the ITO ITO stripe as a mask for cathode vapor deposition. Then, it was installed in another vacuum vapor deposition apparatus, and evacuated until the degree of vacuum in the apparatus reached 3.0 × 10 ⁻⁴ Pa in the same manner as the vapor deposition of the electron transport layer.
Lithium fluoride (LiF) was deposited on the electron transport layer with a film thickness of 0.5 nm using a molybdenum boat at a deposition rate of 0.05 liter / second and a degree of vacuum of 3.0 × 10 ⁻⁴ Pa. The electron injection layer

(Formation of cathode)
Similarly, aluminum was heated by a molybdenum boat to form an aluminum layer having a thickness of 80 nm at a deposition rate of 4 Å / sec and a degree of vacuum of 5.0 × 10 ⁻⁴ Pa to form a cathode.

(Sealing)
Next, the vacuum evaporation apparatus was returned to atmospheric pressure, and the substrate on which the evaporation was performed was once taken out into the atmosphere and transferred to a glove box substituted with nitrogen.
In a glove box substituted with nitrogen, a hygroscopic sheet is attached to the concave portion of the sealing glass plate, and a UV curable resin coating is applied around the concave portion of the sealing glass plate with a dispenser. Were sealed so as to be sealed with a sealing glass plate, and UV light was irradiated with a UV lamp to cure the UV curable resin.

As described above, an organic electroluminescent element having a surface similar to the region partitioned by the bank after the surface of the hole transport layer passed through the bank formation step was obtained.
(Element evaluation)
When this element emitted light at 1000 cd / m ² , the voltage was 8.0 V, the current light emission efficiency was 15.3 cd / A, and it was confirmed that a square light emitting region with a side of 2 mm uniformly emitted light.

Further, when a durability test was conducted by continuously energizing this device at a current density of 30 mA / cm ² , the time until the luminance of the device was reduced to half was 75 hours.
The results are summarized in Table 1.
[Comparative Example 1]
In Example 1, a device was fabricated in the same manner as in Example 1 except that the polar organic solvent washing step was not performed.

(Element evaluation)
When this element emitted light at 1000 cd / m ² , the voltage was 8.5 V, the current light emission efficiency was 15.3 cd / A, and it was confirmed that a square light emission region with a side of 2 mm emits light evenly.
Further, when a durability test was conducted by continuously energizing this device at a current density of 30 mA / cm ² , the time until the luminance of the device was reduced to half was 10 hours.

The results are summarized in Table 1.
[Comparative Example 2]
In Example 1, a device was produced in the same manner as in Example 2 except that ethanol used in the polar organic solvent washing step was changed to toluene which is a nonpolar organic solvent.
(Element evaluation)
When this element emitted light at 1000 cd / m ² , the voltage was 8.5 V, the current light emission efficiency was 11.2 cd / A, and it was confirmed that the square light emission region with a side of 2 mm uniformly emitted light.

Further, when a durability test was conducted by continuously energizing the device at a current density of 30 mA / cm ² , the time until the luminance of the device was reduced to half was 25 hours.
The results are summarized in Table 1.

As shown in Table 1, it can be seen that the organic electroluminescence device formed by the method for producing an organic electroluminescence device of the present invention has a longer driving life.
[Example 2]
From the anode to the formation of the hole transport layer, produced in the same manner as in Example 1,
The bank-forming composition (C1) was changed to the bank-forming composition (C2) prepared by the following procedure, and the hole transport layer surface was resist-treated by the following procedure. A device was produced in the same manner as in Example 1 except that the prepared composition for forming a light emitting layer (D1) was formed in the following procedure.

(Preparation of bank forming composition)
The bank forming composition (C2) was prepared as follows.
Binder resin: 48 parts by weight of a polymer having a repeating structure of formula (iv) (weight average molecular weight 4000),
Ethylenically unsaturated compound: 24 parts by weight of the compound having the structure of the above formula (v),
Ethylenically unsaturated compound: 24 parts by weight of a compound having the structure of the following formula (xii)
Photopolymerization initiator: 3 parts by weight of a compound having the structure of the following formula (xiii)
Surfactant: 1.5 parts by weight of a compound having the structure of formula (vii)
Liquid repellent: Megafax RS-102 (Dainippon Ink Chemical Co., Ltd., active ingredient 40 wt%, methyl isobutyl ketone (MIBK): cyclohexanone = 75: 25 as a solvent) 2.5 parts by weight,
It melt | dissolved in propylene glycol monomethyl ether acetate (PGMEA) as a solvent, and prepared the composition (C2) for bank formation with a solid content concentration of 27 weight%.

(Coating process / Pre-baking process)
Next, the bank forming composition (C2) was applied onto the hole transport layer by spin coating. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. As the spin condition, after rotating at 300 rpm for 2 seconds, it was continuously rotated at 1200 rpm for 3 seconds. After the application, it was heated and dried (prebaked) at 80 ° C. for 60 seconds on a hot plate.

(Development process)
Next, it was immersed in a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) for 120 seconds, then washed with pure water for 10 seconds, and dried by blowing nitrogen. As a result, the entire layer formed using the bank forming composition was removed.
(Polar organic solvent washing process)
Next, it was immersed for 10 seconds at 23 ° C. using ethanol as a polar organic solvent. Thereafter, as a rinsing treatment, running water was supplied for 10 seconds with pure water, and nitrogen blowing was performed for drying.

(Heating process)
Finally, the substrate after the polar organic solvent cleaning step was heated on a hot plate at 230 ° C. for 30 minutes.
(Preparation of light emitting layer forming composition (D1))
50 parts by weight of a compound represented by the following formula (xvi), 50 parts by weight of a compound represented by the following formula (xvii), 5 parts by weight of a compound represented by the following formula (xviii), The resultant was dissolved in 4095 parts by weight of dehydrated xylene and filtered through a 0.2 μm PTFE filter to prepare a light emitting layer forming composition (D2). The composition for forming a light emitting layer was prepared in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm.

(Light emitting layer deposition)
A light emitting layer was formed on a substrate having a bank formed on the hole transport layer by a spin coating method using the composition for forming a light emitting layer (D1). The spin coating was performed in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm, the spin rotation speed was 1500 rpm, and the spin time was 30 seconds. After coating, after pre-drying at 130 ° C. for 1 minute on a hot plate, the unnecessary part on the electrode is wiped off, and then heated and dried in a vacuum at 130 ° C. for 1 hour to form a light-emitting layer having a thickness of 40 nm. did.

(Element fabrication)
From the hole blocking layer to sealing, organic electroluminescence blocking was made in the same manner as in Example 1.
(Element evaluation)
When this element emitted light at 1000 cd / m ² , the voltage was 11.6 V, the current light emission efficiency was 11.2 cd / A, and it was confirmed that a square light emitting region with a side of 2 mm emits light evenly.

Further, when a durability test was conducted by continuously energizing this device at a current density of 30 mA / cm ² , the time until the luminance of the device was reduced to half was 190 hours.
The results are summarized in Table 2.
[Comparative Example 3]
In Example 2, a device was fabricated in the same manner as in Example 2 except that the polar organic solvent washing step was not performed.

(Element evaluation)
When this element emitted light at 1000 cd / m ² , the voltage was 11.6 V, the current light emission efficiency was 14.2 cd / A, and it was confirmed that a square light emitting region with a side of 2 mm emits light evenly.
Further, when a durability test was conducted by continuously energizing this device at a current density of 30 mA / cm ² , the time until the luminance of the device was reduced to half was 10 hours.

  The results are summarized in Table 2.

As shown in Table 2, it can be seen that the organic electroluminescence device produced by the method for producing an organic electroluminescence device of the present invention has a longer driving life.
[Description 2]
Next, polar organic solvent washing was performed between the development step and the heating step in the resist processing.

In Examples 3 and 4 and Comparative Examples 4 and 5, a bank was formed on the hole transport layer as the first organic layer, and an organic electroluminescence device was produced and evaluated.
[Example 3]
In Example 2, except that the exposure process described below was performed between the photoresist coating process / pre-bake process and the development process, the same procedure as in Example 2 was performed. A device having a bank having the following shape was formed, and a light emitting layer as a second organic layer was formed on the first organic layer in the bank opening region.

(Exposure process)
As the exposure apparatus, an exposure apparatus UX-1000SM-ACS01 (manufactured by Ushio Inc.) was used.
A photomask has a vertical aperture width of 30 μm, a horizontal aperture width of 50 μm, a pattern pitch of 300 μm in both vertical and horizontal directions, and a light-shielding portion in a lattice shape, that is, a plurality of patterns with a vertical mask width of 270 μm and a horizontal mask width of 250 μm at 300 μm pitches A side-by-side pattern was used. The gap between the substrate and the photomask was 100 μm.
The exposure conditions were 120 mJ / cm ² (@ 365 nm).

(Bank shape)
The development process and the heating process were performed in the same manner as in Example 2. As a result, the banks formed of the bank forming composition have a rectangular opening with a vertical length of 270 μm and a horizontal width of 250 μm, a vertical bank width of 30 μm, a horizontal bank width of 50 μm, and are arranged at a pitch of 300 μm vertically and horizontally. It was a shape.

(Element evaluation)
The device was energized and it was confirmed that the bank opening emitted light.
Further, when a durability test was conducted by continuously energizing the device at a current density of 30 mA / cm ² , the time until the luminance of the device was reduced to half was 160 hours.
(Residue observation)
Using the three-dimensional non-contact surface shape measurement system Micromap (manufactured by Ryoka Systems Co., Ltd.), the surface of the hole transport layer that has been subjected to the heating step after the bank-forming composition (C2) is removed in the development step and the polar solvent washing step Observations were made. The observation conditions were 50 × objective lens and Phase mode. The surface was smooth and no residue was observed. Further, when Ra (arithmetic mean roughness) and maximum height (maximum height difference) were measured with the above three-dimensional non-contact surface shape measurement system, Ra = 0.39 nm and maximum height = 3.93 nm. It was.

The results are summarized in Table 3.
[Comparative Example 4]
In Example 3, a bank was formed in the same manner as in Example 3 except that the polar organic solvent washing step was not performed. When a light emitting layer was formed on a substrate having a bank formed on the hole transport layer by a spin coating method using the light emitting layer forming composition (D1), the light emitting layer forming composition (D1) was repelled. As a result, coating could not be formed in the bank.

(Residue observation)
When the bank-forming composition (C2) was removed in the development step and the polar solvent washing step and the surface of the hole transport layer after the heating step was observed in the same manner as in Example 4, a residue was confirmed on the surface, and Ra = 1 The maximum height was 12.34 nm.
From this result, since the polar organic solvent washing step was not performed, a resist residue having liquid repellency remained in the area partitioned by the bank, and therefore the composition for forming the light emitting layer was repelled and could not be applied. Conceivable.

  The results are summarized in Table 3.

As shown in Table 3, it can be seen that the organic electroluminescent device formed by the method of manufacturing an organic electroluminescent device of the present invention has a uniform coated surface of the light emitting layer.
[Example 4]
The composition for forming a hole transport layer (B2) prepared by the following procedure was used as the hole transport layer, and the composition for forming the light emitting layer (D2) prepared by the following procedure was used as the light emitting layer. A device was fabricated in the same manner as in Example 3.

(Preparation of composition for forming hole transport layer)
A polymer having a repeating structure of the following formula (xi) (weight average molecular mass 95000) 0.4% by weight was dissolved in toluene as a solvent to prepare a composition for a hole transport layer. As the toluene, commercially available dehydrated toluene was used, and a hole transport layer forming composition (B2) was prepared in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm.

(Preparation of composition for forming light emitting layer)
10 parts by weight of a compound represented by the following formula (xiv),
1 part by weight of a compound represented by the following formula (xv)
It melt | dissolved in 1470 weight part of commercially available dehydrated toluene, and filtered with a 0.2 micrometer PTFE filter, and prepared the composition for light emitting layer formation (D2). The composition for forming a light emitting layer (D2) was performed in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm.

(Element evaluation)
The device was energized and it was confirmed that the bank opening emitted light.
When this device was subjected to a durability test with an initial luminance of 2000 cd / m ^{2 and} energized continuously at a constant current, the time until the luminance of the device was reduced to half was 150 hours.

The results are summarized in Table 4.
[Comparative Example 5]
In Example 4, a bank was formed in the same manner as in Example 4 except that the polar organic solvent washing step was not performed. When a light emitting layer was formed on a substrate having a bank formed on the hole transport layer by a spin coating method using the light emitting layer forming composition (D2), the light emitting layer forming composition (D2) was repelled. As a result, coating could not be formed in the bank.

  The results are summarized in Table 4.

As shown in Table 4, it can be seen that the organic electroluminescence device formed by the method for producing an organic electroluminescence device of the present invention has a uniform light emitting surface.
[Description 3]
Next, in the resist processing, a developing solution containing a polar organic solvent was used in the developing step, and the polar organic solvent was not washed between the developing step and the heating step.

In Example 5 and Comparative Example 6, the surface of the hole transport layer serving as the first organic layer treated with a resist was observed.
[Example 5]
(Preparation of glass substrate)
First, the glass substrate is cleaned in the order of ultrasonic cleaning with an aqueous surfactant solution, water cleaning with ultrapure water, ultrasonic cleaning with ultrapure water, and water cleaning with ultrapure water, and then dried with compressed air blow. UV ozone cleaning was performed.

(Formation of hole injection layer and hole transport layer)
Next, a hole injection layer and a hole transport layer were formed on the previous glass substrate in this order as in Example 1.
(Preparation of bank forming composition)
Next, a bank forming composition solution (C3) was prepared.
Binder resin: 48 parts by weight of a polymer having a repeating structure of the above formula (iv) (weight average molecular weight 4000),
Ethylenically unsaturated compound: 48 parts by weight of the compound having the structure of the formula (v),
Photopolymerization initiator: 3 parts by weight of a compound having the structure of formula (vi)
Photopolymerization initiator: 1.5 parts by weight of a compound having the structure of the formula (vii)
Surfactant: Megafak F475 (Dainippon Ink Chemical Co., Ltd.) 0.1 parts by weight
It melt | dissolved in propylene glycol monomethyl ether acetate (PGMEA) as a solvent, and prepared the composition (C3) for bank formation with a solid content concentration of 37 weight%.

(Preparation of a hole transport layer treated with a bank forming composition)
Next, in the yellow room where the ultraviolet light was cut, the hole injection layer and the hole transport layer were stacked in this order on the substrate, and the holes were formed in the bank forming composition (C3) according to the following procedure. The transport layer surface was treated with a resist.
(Coating process / Pre-baking process)
First, the bank forming composition (C3) was applied by spin coating. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. The spin condition was such that it was rotated at 300 rpm for 2 seconds and then continuously rotated at 700 rpm for 3 seconds. After coating, it was heated and dried on a hot plate at 80 ° C. for 60 seconds.

(Development process)
Next, an aqueous solution in which 2.38 wt% tetramethylammonium hydroxide (TMAH) was dissolved as an alkaline compound and 5 wt% ethanol was dissolved as a polar organic solvent was used as a developer. It was immersed in this developing solution for 120 seconds. Thereafter, washing with pure water was performed for 10 seconds as a rinsing treatment, and nitrogen blowing was performed for drying. As a result, the entire layer formed using the bank forming composition was removed.

(Heating process)
Finally, the substrate after the development process was heated on a hot plate at 230 ° C. for 30 minutes to produce an observation sample.
(Residue observation)
Next, when the hole transport layer surface treated with the bank forming composition was observed in the same manner as in Example 4, the surface was smooth and no residue was observed. Further, Ra = 0.42 nm and the maximum height = 8.84 nm.

From this, it can be seen that by developing using the developer in the second of the present invention, the residue of the bank forming composition is small.
The results are shown in Table 5.
[Comparative Example 6]
An observation sample was produced in the same manner as in Example 5 except that an aqueous solution in which 2.38% of TMAH was dissolved was used as the developer.

(Residue observation)
In the same manner as in Example 5, the surface of the hole transport layer treated with the bank forming composition was observed using a three-dimensional non-contact surface shape measurement system Micromap (manufactured by Ryoka Systems Co., Ltd.). Many residues were confirmed on the surface as islands. Moreover, it was Ra = 5.04nm and PV = 38.72nm.

  The results are shown in Table 5.

As shown in Table 5, it can be seen that the surface of the hole transport layer treated with the bank-forming composition is flat in the organic electroluminescent device produced by the method for producing an organic electroluminescent device of the present invention.
[Explanation 4]
Next, in the resist processing, element production evaluation was performed using a developer containing a polar organic solvent in the development step.

In Example 6, the hole transport layer as the first organic layer was resist-treated to form a bank, and in Examples 7, 8 and Comparative Example 6, the hole transport layer as the first organic layer was on the hole transport layer. A bank was formed, and an organic electroluminescent device was produced and evaluated.
In the resist processing of Examples 6 and 7, the polar organic solvent was washed between the development process and the heating process.

[Example 6]
(Formation of anode)
The anode was formed in the same manner as in Example 1.
(Formation of hole injection layer)
Next, a composition for forming a hole injection layer was prepared. A polymer having a repeating structure represented by the following formula (xix) (weight average molecular mass 60000) 2% by weight and a compound represented by the above formula (ii) 0.4% by weight are dissolved in ethyl benzoate as a solvent to obtain a solid content. A hole injection layer forming composition (A2) having a concentration of 2.4% by weight was prepared.

  A hole injection layer was formed on the cleaned ITO substrate by the spin coating method using the composition for forming a hole injection layer. The spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, the spin rotation speed was 1500 rpm, and the spin time was 30 seconds. After coating, the substrate was heated and dried on a hot plate at 80 ° C. for 1 minute, and then baked in an oven atmosphere at 230 ° C. for 1 hour to form a hole injection layer having a thickness of 30 nm.

(Formation of hole transport layer)
Next, a composition for forming a hole transport layer was prepared. A polymer having a repeating structure of the formula (xi) (weight average molecular mass 95000) 1.4% by weight was dissolved in cyclohexylbenzene as a solvent to prepare a composition for a hole transport layer. Cyclohexylbenzene was dehydrated by adding a molecular sieve to a commercial product, and a composition for forming a hole transport layer was prepared in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm.

The substrate coated with the hole injection layer was placed in a nitrogen glove box, and a hole injection layer was formed on the hole injection layer by the spin coating method using the above composition for forming a hole transport layer. The spin rotation speed was 1500 rpm and the spin time was 30 seconds. After coating, baking was performed on a hot plate at 230 ° C. for 1 hour to form a 20 nm-thick hole transport layer.
Preparation of the composition for forming a hole transport layer, spin coating, and baking were all performed in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm without being exposed to the atmosphere.

(Preparation of bank forming composition)
Two layers of banks were formed using two different types of bank forming compositions.
(Preparation of bank forming composition (C4))
A bank forming composition solution (C4) was prepared.
75 parts by weight of polyvinylpyrrolidone resin K-30 (manufactured by Nippon Shokubai Co., Ltd.)
25 parts by weight of polyvinylpyrrolidone resin K-90 (manufactured by Nippon Shokubai Co., Ltd.)
0.2 parts by weight of a polyether-modified silicone surfactant BYK-330 (Bic Chemie, solid content concentration 51%, methoxypropyl acetate)
Dissolved in an 8: 2 mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and 2-methoxybutanol (MB),
A bank forming composition C4) having a solid content of 0.5% by weight was prepared.

(Preparation of bank forming composition (C5))
First, an alkali-soluble resin represented by the following formula (xxi) was synthesized as follows.
145 parts by weight of propylene glycol monomethyl acetate was stirred while being purged with nitrogen, and the temperature was raised to 120 ° C. 20 parts by weight of styrene, 57 parts by weight of glycidyl methacrylate, and 82 parts by weight of monoacrylate FA-513M (manufactured by Hitachi Chemical Co., Ltd.) having a tricyclodecane skeleton were added dropwise thereto, and the mixture was further stirred at 140 ° C. for 2 hours. Next, the reaction vessel was purged with air, 0.7 parts by weight of trisdimethylaminomethylphenol and 0.12 parts by weight of hydroquinone were added to 27 parts by weight of acrylic acid, and the reaction was continued at 120 ° C. for 6 hours. Thereafter, 52 parts by weight of tetrahydrophthalic anhydride (THPA) and 0.7 parts by weight of triethylamine were added and reacted at 120 ° C. for 3.5 hours to obtain an alkali-soluble resin (xxi). The obtained alkali-soluble resin (xxi) had a weight average molecular weight of 8,000.

Next, a bank forming composition solution (C5) was prepared.
First, binder resin: 48 parts by weight of alkali-soluble resin (xxi),
Ethylenically unsaturated compound: 24 parts by weight of dipentaerythritol hexaacrylate (DPHA) (manufactured by Nippon Kayaku Co., Ltd.)
Ethylenically unsaturated compound: 24 parts by weight of the compound represented by the formula (xii),
Ethylenically unsaturated compound: 5 parts by weight of a compound represented by the following formula (xxii)
Photopolymerization initiator: 1.5 parts by weight of Irgacure 907 (manufactured by Ciba Specialty Chemicals)
Polyether-modified silicone surfactant: 0.2 part by weight of BYK-330 (manufactured by Big Chemie)
Liquid repellent: A composition for forming a bank having a solid content concentration of 25% by weight by dissolving 1.63 parts by weight of MegaFac RS-102 (manufactured by Dainippon Ink & Chemicals) in propylene glycol monomethyl ether acetate (PGMEA) as a solvent. A product solution (C5) was prepared.

(Preparation of a hole transport layer treated with a bank forming composition)
Next, in a yellow room where ultraviolet light is cut, a bank-forming composition (C4) is first applied by spin coating to a substrate on which a hole injection layer and a hole transport layer are stacked in this order. Applied. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. As the spin condition, after rotating at 300 rpm for 2 seconds, it was continuously rotated at 500 rpm for 30 seconds. After coating, it was heated and dried on a hot plate at 80 ° C. for 60 seconds.

After the bank forming composition (C4) was applied, the bank forming composition (C5) was further applied by spin coating. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. The spin condition was rotated at 300 rpm for 2 seconds and then continuously rotated at 650 rpm for 30 seconds. After coating, it was heated and dried on a hot plate at 80 ° C. for 60 seconds.
In this manner, the bank-forming composition (C4) and the bank-forming composition (C5) were laminated on the hole transport layer.

(Development process)
Next, 0.48 wt% tetramethylammonium hydroxide (TMAH) as an alkaline compound, 0.4 wt% Emulgen A-60 (manufactured by Kao Corporation) as a nonionic surfactant, and 2 wt% ethanol as a polar organic solvent are dissolved. The aqueous solution was used as a developer.

An automatic processor (manufactured by Takizawa Sangyo Co., Ltd.) was used for development. Development conditions were as follows: the developer was jetted for 30 seconds at a liquid temperature of 23 ° C. and a liquid pressure of 0.1 MPa. Thereafter, pure water was sprayed for 30 seconds at a liquid temperature of 23 ° C. and a liquid pressure of 0.1 MPa as a rinse treatment. As a result, the entire layer formed using the bank forming composition was removed.
(Polar organic solvent washing process)
Subsequently, using ethanol as a polar organic solvent, washing was performed by spraying at a liquid temperature of 23 ° C. and a liquid pressure of 0.1 MPa for 5 seconds. Thereafter, as a rinsing treatment, pure water was injected for 30 seconds at a liquid temperature of 23 ° C. and a liquid pressure of 0.1 MPa, and dried by nitrogen blowing.

(Heating process)
Finally, the substrate that has undergone the above-mentioned bureau west friendship solvent cleaning process is placed in a nitrogen glove box, heated on a hot plate in the nitrogen glove box at 230 ° C. for 30 minutes, and the hole transport layer surface is treated with the bank forming composition. did.
The nitrogen glove box had an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm.

(Formation of light emitting layer)
Next, a composition for forming a light emitting layer for coating and forming a light emitting layer was prepared.
(Preparation of composition for forming light emitting layer)
100 parts by weight of the compound represented by the formula xiv,
10 parts by weight of the compound represented by the formula xv,
It was dissolved in cyclohexylbenzene and filtered through a 0.2 μm PTFE filter to prepare a 3.1 wt% composition for forming a light emitting layer (D3).

Cyclohexylbenzene was dehydrated by adding a molecular sieve to a commercially available product, and the light emitting layer forming composition (D3) was prepared in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm.
(Light emitting layer deposition)
On the positive hole transport layer which processed the bank formation composition, the light emitting layer was formed with the spin coat method using the light emitting layer formation composition (D3). The spin coating was performed in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm, the spin rotation speed was 1200 rpm, and the spin time was 30 seconds. After coating, the film was pre-dried at 130 ° C. for 1 minute on a hot plate, and then dried by vacuum heating on a hot plate at 130 ° C. for 1 hour to form a light-emitting layer having a thickness of 49 nm.

This board | substrate was arrange | positioned without exposing to the atmosphere in the chamber of the vacuum evaporation system connected with the glove box. The degree of vacuum in the chamber was 1.0 × 10 ⁻⁵ Pa. A vapor deposition mask was arranged in a predetermined area on the substrate, and necessary vapor deposition materials were individually placed in advance in the chamber in crucibles wound with heater wires.
(Formation of hole relaxation layer)
First, a crucible containing a compound represented by the following formula (xxiii) was energized and heated with a heater wire and deposited on the light emitting layer. The deposition conditions were such that the degree of vacuum during deposition was 1.0 × 10 ⁻⁵ Pa, the deposition rate was 1.0 Å / s, and the hole relaxation layer was formed with a thickness of 10 nm.

(Formation of electron transport layer)
Next, the crucible containing Alq ₃ was heated by energization with a heater wire and deposited on the first light emitting layer. The deposition conditions were such that the degree of vacuum during deposition was 1.0 × 10 ⁻⁵ Pa, the deposition rate was 1.0 Å / s, and the electron transport layer was formed with a thickness of 30 nm.

(Cathode formation)
Next, the substrate was placed in another vacuum chamber without being exposed to the atmosphere, and a 2 mm-wide stripe-shaped shadow mask was placed as a mask for cathode vapor deposition so as to be orthogonal to the ITO ITO stripe. The degree of vacuum in the chamber was 1 × 10 ⁻⁵ Pa. As a cathode, first, a molybdenum boat containing lithium fluoride (LiF) was energized and heated and deposited on the electron transport layer. The vapor deposition conditions were as follows: the degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁵ Pa, the vapor deposition rate was 0.05 Å / s, and the film thickness was 0.5 nm. Finally, a molybdenum boat containing aluminum was heated by energization to deposit a cathode. The deposition conditions were such that the degree of vacuum during deposition was 5.0 × 10 ⁻⁵ Pa, the deposition rate was 3.0 Å / s, and a film thickness of 80 nm was formed.

(Sealing)
Next, the substrate was transferred to a glove box substituted with nitrogen without being exposed to the atmosphere. In a glove box substituted with nitrogen, a hygroscopic sheet is attached to the concave portion of the sealing glass plate, and a UV curable resin coating is applied around the concave portion of the sealing glass plate with a dispenser. Were sealed so as to be sealed with a sealing glass plate, and UV light was irradiated with a UV lamp to cure the UV curable resin.

As described above, an organic electroluminescent device having a bank formed of the bank forming composition on the hole transport layer was obtained.
(Element emission check)
When this element was energized, uniform blue light emission was obtained. When this device emitted light at 1000 cd / m ² , the voltage was 7.4 V and the current light emission efficiency was 5.0 cd / A. Further, when the lifetime test of this device was carried out by applying a constant current continuously at an initial luminance of 2000 cd / m ² , the time until the luminance was reduced to half was 500 hours.

The results are summarized in Table 6.
Hereinafter, in Examples 7 and 8 and Comparative Example 7, an organic electroluminescence device actually having a bank was produced and evaluated.
[Example 7]
(Anode formation-Photoresist application / pre-bake)
The process from the anode formation to the photoresist coating / prebaking process was the same as in Example 6.

(Exposure process)
Next, exposure was performed. The same apparatus as that used in Example 3 was used as the exposure apparatus.
The photomask used was a mask having an aperture width of 30 μm in both vertical and horizontal directions, a pattern pitch of 100 μm in both vertical and horizontal directions, and having a light-shielding portion in a lattice shape, that is, a pattern in which a plurality of masks having a vertical and horizontal mask width of 70 μm and a bank width of 30 μm. The gap between the substrate and the photomask was 100 μm. The exposure conditions were 1200 mJ / cm ² (@ 365 nm).

(Development process / heating process)
The development process and the heating process were performed in the same manner as in Example 6. Thus, the bank formed of the bank forming composition had a mesh shape in which the opening was a square with a side of 70 μm, the bank width was 30 μm, and the vertical and horizontal lines were arranged at a pitch of 100 μm.
(Formation of light emitting layer)
Next, a composition for forming a light-emitting layer for wet-forming a light-emitting layer in a region partitioned by banks was prepared.

(Preparation of composition for forming light emitting layer)
50 parts by weight of the compound represented by the formula xvi,
50 parts by weight of the compound represented by the formula xvii,
5 parts by weight of the compound represented by the formula xviii
A luminescent layer forming composition (D4) was prepared by dissolving in cyclohexylbenzene to obtain a 0.5 wt% solution and filtering through a 0.2 μm PTFE filter.

(Light-emitting layer coating)
The light emitting layer was formed in the inkjet apparatus using the light emitting layer forming composition (D4) on the board | substrate which formed the bank on the positive hole transport layer. Inkjet used 25 nozzles at the same time, and 25 pl of ink was ejected onto each 25 × 50 opening area to apply a light emitting layer.

Next, the substrate coated with the light-emitting layer was transferred into a nitrogen glove box having an oxygen concentration of 1.0 ppm and a moisture concentration of 1.0 ppm, and 130 ° C. for 1 hour under a reduced pressure of 10 kPa on a reduced pressure hot plate installed in the glove box. It dried and formed the light emitting layer with a film thickness of 25 micrometers.
(Hole relaxation layer to cathode)
Next, the substrate was once taken out into the atmosphere and set in a vapor deposition apparatus. In the same manner as in Example 6, after forming a hole relaxation layer, an electron transport layer, and a cathode, sealing was performed to produce an organic electroluminescent device. .

(Element emission check)
This element was energized, and it was confirmed that the bank opening emitted green light.
The results are summarized in Table 6.

[Example 8]
(Formation of anode, formation of hole injection layer)
The process from formation of the anode to formation of the hole transport layer was performed in the same manner as in Example 6.

(Preparation of bank forming composition)
Next, a bank forming composition solution (C6) was prepared.
First, binder resin: 48 parts by weight of alkali-soluble resin (xxi),
Ethylenically unsaturated compound: 24 parts by weight of dipentaerythritol hexaacrylate (DPHA) (manufactured by Nippon Kayaku Co., Ltd.)
Ethylenically unsaturated compound: 24 parts by weight of the compound represented by the formula (xii),
Ethylenically unsaturated compound: 5 parts by weight of a compound represented by the following formula (xxii)
Photopolymerization initiator: 1.5 parts by weight of Irgacure 907 (manufactured by Ciba Specialty Chemicals)
Polyether-modified silicone surfactant: 0.2 part by weight of BYK-330 (manufactured by Big Chemie)
Liquid repellent: A composition for forming a bank having a solid content concentration of 25% by weight by dissolving 0.65 parts by weight of MegaFac RS-102 (manufactured by Dainippon Ink and Chemicals, Inc.) in propylene glycol monomethyl ether acetate (PGMEA) as a solvent. A product solution (C6) was prepared.

(Film formation of bank forming composition)
Next, in Example 6, the bank-forming composition (C6) was used instead of the bank-forming composition (C5), and in the same manner as in Example 6, the bank-forming composition ( C4) and the bank forming composition (C6) were laminated.
(Exposure process)
Next, exposure was performed. The same apparatus as that used in Example 3 was used as the exposure apparatus.
As the photomask, a mask having an aperture width of 30 μm in both length and width and a pattern pitch of 400 μm in length and width and having a light-shielding portion in a lattice shape, that is, a pattern in which a plurality of masks having a vertical and horizontal mask width of 370 μm and a bank width of 30 μm are arranged. The gap between the substrate and the photomask was 100 μm. The exposure conditions were 400 mJ / cm ² (@ 365 nm).

(Development process)
Next, development was performed. The development is performed by immersing in a developer in which 0.48 wt% of tetramethylammonium hydroxide (TMAH) as an alkaline compound and 10 wt% of ethanol as a polar organic solvent are dissolved in pure water for 30 seconds, and then with pure water. Washing with water was performed for 10 seconds and drying was performed by blowing nitrogen.

(Heating process)
Finally, the developed substrate was placed in a clean oven and heated at 230 ° C. for 30 minutes. As a result, the opening has a square shape with a side of 370 μm, a width of 30 μm, a height of 1.2 μm, and 4 in the vertical and horizontal directions.
Mesh-shaped banks arranged at a pitch of 00 μm were formed.
(Formation of light emitting layer)
Next, a composition for forming a light emitting layer for coating and forming a light emitting layer was prepared.

(Preparation of composition for forming light emitting layer)
25 parts by weight of the compound represented by the formula (xvi), 75 parts by weight of the compound represented by the following formula (xxv), and 5 parts by weight of the compound represented by the following formula (xxvi) Was dissolved in 3370 parts by weight of xylene, and the insoluble matter was filtered with a 0.2 μm PTFE filter to prepare a composition for forming a light emitting layer (D5).

  The light emitting layer forming composition (D5) was prepared in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm.

(Light emitting layer deposition)
On the hole transport layer in which the bank was formed, a light emitting layer was formed by spin coating using the light emitting layer forming composition (D5). The spin coating was performed in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a water concentration of 1.0 ppm, the spin rotation speed was 1500 rpm, and the spin time was 30 seconds. Subsequently, it vacuum-dried at 130 degreeC on the hotplate for 1 hour, and it dried, and formed the light emitting layer with a film thickness of 60 nm.

(Hole relaxation layer to cathode)
Next, in the same manner as in Example 6, after forming a hole relaxation layer, an electron transport layer, and a cathode, sealing was performed to produce an organic electroluminescent element.
(Element emission observation)
When this element was energized, it was confirmed that green light was emitted uniformly from all the bank openings within 2 mm × 2 mm □.

The results are summarized in Table 7.
[Comparative Example 7]
In Example 8, a device was prepared in the same manner as in Example 8 except that a developing solution in which tetramethylammonium hydroxide (TMAH) was dissolved in 0.48 wt% pure water as an alkaline compound was used in the developing step.

(Element emission observation)
When this element was energized, in a plurality of bank openings within 2 mm × 2 mm □, there were openings that emitted light brightly and openings that emitted light darkly, and emitted green light non-uniformly.
From this, it is considered that there is a bank opening portion with a large amount of residue or unevenness in the thickness of the light emitting layer due to the large amount of residue.

  The results are summarized in Table 7.

  As shown in Table 7, it can be seen that the organic electroluminescence device produced by the method for producing an organic electroluminescence device of the present invention has a uniform light emitting surface.

  The present invention relates to various fields in which organic electroluminescent elements are used, for example, light sources (for example, light sources of copiers, flat panel displays (for example, for OA computers and wall-mounted televisions) and surface light emitters). It can be suitably used in the fields of liquid crystal displays and backlights of instruments), display panels, indicator lamps and the like.

1 Substrate
2 Anode
3 Hole injection layer
4 hole transport layer
5 banks
6 Light emitting layer
7 Cathode
8 Electron injection layer
9 Electron transport layer
10a-10d organic electroluminescent device
11 Electron blocking layer

Claims (11)

A first electrode and a second electrode formed to face the first electrode, between the first electrode and the second electrode,
Method for manufacturing an organic electroluminescent device comprising: a first organic layer, a bank formed in a pattern on the first organic layer, and a second organic layer formed in a region partitioned by the bank In
A method for producing an organic electroluminescent device comprising: a developing step and a heating step in the step of forming the bank, and a step of washing with a polar organic solvent between the developing step and the heating step . A first electrode and a second electrode formed to face the first electrode, between the first electrode and the second electrode,
Method for manufacturing an organic electroluminescent device comprising: a first organic layer, a bank formed in a pattern on the first organic layer, and a second organic layer formed in a region partitioned by the bank In
A method for producing an organic electroluminescent device, comprising: a developing step in the step of forming the bank, wherein the developing step is performed using a developer containing an alkaline compound, a polar organic solvent, and water. .   The method for producing an organic electroluminescent element according to claim 1, wherein the polar organic solvent is a compound containing an oxygen atom in a molecule.   4. The method according to claim 2, further comprising: a developing step and a heating step in the step of forming the bank, and a step of washing with a polar organic solvent between the developing step and the heating step. The manufacturing method of the organic electroluminescent element.   Ra (arithmetic mean roughness) of the surface of the first organic layer in the region partitioned by the bank after forming the bank is 1.0 nm or less and / or the maximum height (maximum height difference) is 10 nm or less. The method for producing an organic electroluminescent element according to claim 1, wherein   The method of manufacturing an organic electroluminescent element according to claim 1, wherein the second organic layer is a light emitting layer.   The method of manufacturing an organic electroluminescent element according to any one of claims 1 to 6, wherein the first organic layer is a hole injection layer or a hole transport layer.   The method for producing an organic electroluminescent element according to any one of claims 1 to 7, wherein the first organic layer and / or the second organic layer is formed by a wet film forming method.   An organic electroluminescence device manufactured by the manufacturing method according to claim 1.   An organic EL display comprising the organic electroluminescent element according to claim 9.   An organic EL illumination comprising the organic electroluminescent element according to claim 9.

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