JP7230675B2 - Barrier film, method for producing barrier film, barrier film laminate, and electronic device - Google Patents

Description

The present invention relates to a barrier film, a method for producing a barrier film, a barrier film laminate, and an electronic device. More particularly, the present invention relates to a barrier film having high film density, fault resistance, stress resistance, and excellent barrier properties against harmful substances, a method for producing the same, a barrier film laminate, and an electronic device.

<How to use gas barrier film>
In our social life and industrial fields, gas barrier films are used in a wide variety of fields. In fields closely related to daily life, it is applied to food packaging materials, soft packaging materials for beverage plastic bottles, packaging of medicines and the like. On the other hand, in the industrial field, electronic component materials that make up various devices such as optical elements that are electronic devices, display devices such as liquid crystal displays and organic EL (electro luminescence) displays, various semiconductor devices, solar cells, etc. Materials with barrier properties are used to protect them from oxygen, water vapor, halogen gas, sulfur-based corrosive gas, etc. in the air.

In order to protect the electronic devices from harmful gases and the like, high moisture resistance and harmful gas barrier properties are required, and gas barrier films are used as an example thereof.

Flexible electronic devices that use gas barrier film have the advantage of being able to seal parts and parts that require high moisture resistance and resistance to harmful gases in multiple units with gas barrier film and then cut them into individual units. have.

In recent years, there has been a demand for narrower bezels in electronic devices such as organic EL elements, and the distance between the cutting position and parts or parts that require high moisture resistance has become shorter. There are also new problems such as the intrusion of gases and the occurrence of cracks at the cut portion during cutting.

In addition, with the development of IoT, it is required to arrange adjacent parts and parts with different thicknesses, and a gas barrier film that maintains high gas barrier properties even in a sealing form with a step is required.

<Structure of gas barrier film>
Gas barrier films currently in use generally have a structure in which a plastic film such as a polyethylene terephthalate (PET) film is used as a support, and a gas barrier film that exhibits gas barrier properties is formed thereon. have. As gas barrier films used for gas barrier films, for example, layers made of various inorganic compounds such as silicon nitride, silicon oxide, and aluminum oxide are known.

Thin film formation by a vacuum film formation method such as sputtering or plasma CVD (chemical vapor deposition) is used to form the inorganic layer made of these inorganic compounds.

In a gas barrier film composed of such an inorganic compound, as a configuration for obtaining high gas barrier performance, an organic layer composed of an organic compound and an inorganic layer composed of an inorganic compound are alternately laminated on a support. An organic-inorganic laminated hybrid gas barrier film (hereinafter also referred to as a laminated gas barrier film) having a laminated structure is known. However, in the method of forming a gas barrier film having a multi-layer structure, several layers are laminated in order to obtain a high gas barrier property with a water vapor permeability of 1.0×10 ⁻³ g/(m ² ·24 hr) or less. Since it is necessary to form a thick gas barrier film, the prevention of water intrusion from the side into the organic layer and the like and crack resistance during cutting were insufficient.

A gas barrier film is a film formed of a thin film that has the role of blocking the passage of molecules of harmful gases (water vapor, halogen gas, sulfuric gas, ammonia, gases composed of various organic solvent molecules, etc.).

Generally, gas barrier films are processed by laminating multiple thin films on a plastic film that serves as a support, or they are formed to directly cover the entire device to eliminate the effects of harmful gases. The main form is to use

<Why are gas barrier films multi-layered? >
The reason why a plurality of thin films are laminated and used as described above is that the film having barrier properties can be considered as a kind of "molecular sieve". In other words, one film has the effect of "blocking" harmful gases with a certain probability. It is effective.

Alternatively, the gas barrier film can be considered as a "molecular labyrinth". Hazardous gases and water molecules that have entered the maze are less likely to reach constituent members of the electronic device as the maze becomes more complicated. By stacking layers having such properties, the probability of arrival of harmful gases and the like can be further reduced.

<Problem of polymer barrier film>
The materials forming the gas barrier film are roughly divided into two types: polymers and ceramics. Each characteristic is described below.

A polymer is a suitable material for forming a smooth, large-area continuous film due to the magnitude of entropy derived from the various shapes and molecular weight distributions of its molecules.

On the other hand, since polymers basically have the property of phase separation between polymer chains, there are gaps between polymer chains that allow small molecules to pass through. There are many crystalline polymers among polymers, but they do not completely organize all the polymer chains to form crystals, but rather specific parts of the polymer chains self-organize in a specific range to form partial crystals. Only the crystalline part is so dense that even small harmful molecules cannot pass through, but harmful gases can easily pass through the interface between the crystal and the amorphous part and the amorphous part. A barrier film cannot be formed.

In addition, the fact that the polymer film has good film-forming properties due to the effect of entropy, as described above, can explain that it is unsuitable as a "molecular sieve" from a thermodynamic point of view.

Considering the second law of thermodynamics (-ΔG = -ΔH + TΔS), polymers with molecular chains of various shapes and molecular weights differ most from other materials in that they have large entropy (ΔS). In the second law of thermodynamics, G represents Gibbs energy, H represents enthalpy, and T represents absolute temperature.

In other words, considering that −ΔG, which is an index of the stability of the barrier film during film formation, is almost made up of the TΔS term, this term is the product of the temperature T, so the film becomes more stable as the temperature rises. I understand.

In other words, the membrane changes at low and high temperatures, that is, the properties of the membrane (for example, the compactness of the polymer chains, and thus the permeability of the molecules) change depending on the temperature. It can be explained that it cannot be a "molecular sieve".

However, since films formed from polymers demonstrate their flexibility and toughness due to the complex entanglement of polymer chains, another requirement, the "molecular labyrinth effect," was determined to be significant. can.

<Problem of ceramic barrier film>
On the other hand, the properties of ceramic films typified by metal oxides are in contrast to those of polymers. The rigidity of the ceramic film is a material that exhibits a high effect as a "molecular sieve" mainly due to the compactness of the constituent molecules, that is, the magnitude of the intermolecular enthalpy (-ΔH).

However, ceramic films are hard and inflexible, and epitaxial growth over a large area is difficult regardless of the film formation method. In other words, although the ceramic film has excellent characteristics as a "molecular sieve", it has a large number of defects, which significantly reduce the effect of the "molecular sieve".

<Problem of metal thin film>
On the other hand, there is a barrier film that exhibits a barrier function as a single layer without lamination, and an example thereof is a metal thin film. Since metals have ductility, it is possible to form flexible thin barrier films with extremely few defects, and they are commonly used as food packaging materials and pharmaceutical packaging materials.

However, a barrier film made of metal completely blocks light and electromagnetic waves, so it is necessary for applications that should not block them, such as media such as light-emitting elements and display members, communication, and signal processing. It is unsuitable for applications that emphasize designability, and the range of use is limited.

<Reasons why low-molecular-weight organic compounds are unsuitable for barrier films>
On the other hand, organic substances different from the above polymers include low-molecular-weight organic compounds, but basically they cannot be expected to have the same entropy effect as polymers, so they are not suitable for smoothly and stably forming large-area thin films. In addition, since it is not as dense as ceramics, its effect as a "molecular sieve" is inferior to that of ceramics. Furthermore, since organic matter itself undergoes a purification process called "recrystallization" when it is mass-produced, low-molecular-weight organic compounds that can be used on a large scale for industrial purposes are basically acicular or polyhedral crystals that are easy to filter and dry. There is no precedent for the industrial use of an organic compound that can epitaxially grow a thin film over a large area.

<Problem of self-assembled monolayer>
In recent years, self-assembled monolayers (SAMs) using relatively low-molecular-weight compounds have the effect of modifying the properties of various substrate surfaces, so they can be applied to various devices. Sexuality has been examined and paid attention to.

SAM is the interaction of van der Waals forces between molecules when organic compound molecules having a specific structure are chemisorbed onto a substrate such as metal, indium tin oxide (ITO), silicon, or glass. It is obtained by spontaneous self-organization by action to form a molecular assembly having a structure in which the molecules are highly regularly oriented.

However, since the formation of this self-assembled monomolecular film occurs in a self-aligned manner, depending on the surface properties of the base material, molecular-sized defects and holes may be formed in the film. When these molecular size defects occur, the barrier function of the self-assembled monolayer is impaired, so the self-assembled monolayer is used as a barrier film or a protective layer (passivation layer) in products. In this case, there is a problem that the types of substrates that can be applied to products are limited, and practical application is difficult (see, for example, Patent Documents 1 and 2).

<Possibility of effective barrier film formation even with low-molecular-weight organic compounds>
Low-molecular-weight organic compounds are substances that can be intentionally designed with a variety of molecular structures by using the technique of organic synthesis. Making use of this characteristic to make possible what was not possible before, and developing materials that are easier to actively and positively impart performance than other materials, such as polymers, ceramics, and metals, is the future industry. There is a possibility that low-molecular-weight organic compounds will replace low-molecular-weight organic compounds as materials that impart barrier properties in the field of electronic devices in particular.

JP-A-2002-327283 Japanese Patent Application Laid-Open No. 2006-22103

The present invention has been made in view of the above problems and circumstances, and the problem to be solved is to provide a gas or liquid barrier film using a self-organizing, relatively low-molecular-weight organic compound, and a method for producing the same. That is. A further object is to provide a barrier film laminate and an electronic device using the barrier film.

In the process of studying the causes of the above problems in order to solve the above problems, the inventors of the present invention have found that a barrier film characterized by being mainly composed of organic compound molecules having at least a self-filling structure has improved film density, The present inventors have found that a barrier film or the like having high failure/defect resistance, high stress resistance, and excellent barrier properties against harmful substances can be realized, leading to the present invention.

That is, the above problems related to the present invention are solved by the following means.

1. A barrier film against gases or liquids,
consisting mainly of molecules of organic compounds in at least self-filling structures,
A barrier film , wherein the molecule of the organic compound has 3-fold, 4-fold or 6-fold rotational symmetry .

2 . A barrier film against gases or liquids,
consisting mainly of molecules of organic compounds in at least self-filling structures,
A barrier film composed of molecules of the organic compound is prepared on a silicon wafer, and in an X-ray diffraction spectrum obtained by X-ray diffraction measurement of the barrier film, the intensity of the highest peak is 500 counts or more, and the peak is A barrier film having a half-value width of 1.0 degree or less.

3 . 3. The barrier film according to item 1 or 2 , wherein the organic compound has a molecular weight of 1000 or less.

4 . 4. The barrier film according to any one of items 1 to 3 , wherein the barrier film is a coating film.

5 . A barrier film manufacturing method for manufacturing the barrier film according to any one of items 1 to 4 , wherein the barrier film is formed by a wet coating method. Method.

6 . 6. The method for producing a barrier film according to item 5 , wherein the wet coating method is an inkjet printing method, a spin coating method or a dispenser method.

7 . A barrier film laminate having barrier properties against gases or liquids,
5. A barrier film laminate comprising at least the barrier film according to any one of items 1 to 4 and a barrier film of another type, wherein the barrier film of another type is made of an inorganic material.

8 . An electronic device comprising the barrier film according to any one of items 1 to 4 .

9 . 9. The electronic device according to item 8 , wherein the electronic device is an electroluminescence element.

10 . 9. The electronic device according to item 8 , wherein the electronic device is a solar cell, a semiconductor, an LED or a secondary battery.

By means of the above means of the present invention, a barrier film having high film density, failure/defect resistance, stress resistance, and excellent barrier properties against harmful substances, a method for producing the same, a barrier film laminate having the barrier film, and an electronic device are provided. can do.

Although the expression mechanism or action mechanism of the effects of the present invention has not been clarified, it is speculated as follows.

The barrier film of the present invention is a film mainly composed of organic compound molecules having a self-filling structure, and is composed of organic molecules that can be mass-produced by a recrystallization method in an appropriate solvent. When formed, it is a film composed of molecules that are defect-free, dense, and arranged in a regular molecular arrangement.

The inventors of the present application have been earnestly studying the search for functional molecules based on novel ideas for many years based on the research and development of electronic devices such as organic transistor materials and organic EL materials.

As a result, as the first result, the inventors of the present invention independently molecularly designed and developed hexa-2-pyridylbenzene (hereinafter abbreviated as "HPB"). It has been found that it satisfies the conditions defined above and exhibits extremely effective effects as a constituent material of a barrier film.

Conventionally, HPB has been widely studied as an electron-transporting material for organic EL. However, the inventors of the present invention have found that a thin film formed from HPB has an excellent function as a barrier film and can be used as a gas barrier film or a sealing material. As a material to be applied to the formation of a barrier film, it was found to be a barrier film-forming material based on a totally unprecedented new concept.

When the HPB shown above is dissolved in an alcohol-based solvent, the hydroxy groups of the alcohol form hydrogen bonds with the six nitrogen atoms present in the molecule. It is a compound with properties that guarantee its properties.

When this solution is applied to the substrate, the excess solvent dries at first and begins to form a film, and in the latter stage of drying, the hydrogen-bonded alcohol gradually detaches and finally disappears completely. , the molecules self-assembled to form a regular and dense crystalline film in which HPB was stacked layer by layer.

As a result of forming HPB films on various substrates by a coating method, the molecular thickness of HPB is about 4 Å. It turned out to be an ordered film in which these molecules are laminated in a columnar shape.

In addition, the fact that the above-mentioned hydrogen bonding of alcohol contributes to both solubility and molecular arrangement is that no clear order is detected in XRD in the HPB thin film produced by evaporation deposition, that is, a peak exists. The hydrogen bond formation of alcohols is involved in imparting solubility, and the alcohols are gradually removed while breaking the hydrogen bonds, resulting in orderly self-organization. This is the mechanism by which barrier films, which are thin films of highly ordered low-molecular-weight organic compounds, are formed.

Such a technical mechanism of the present invention is not known at all in the formation of barrier films and the formation of flattening films, and the recrystallization of low-molecular-weight organic compounds, which has been a tradeoff in the past, has been a trade-off, that is, industrial productivity. and epitaxial growth properties. This is a result that suggests

<Unexpectedness of the present invention>
In the present invention, in response to the above problems that have not been realized so far, a specific molecular design concept can be constructed, and a specific compound can be designed and synthesized according to it. In applications in various fields of, the scope of application can be expanded.

As a result of examining various compounds according to the above design concept, the inventors of the present invention found that, other than the hexa-2-pyridylbenzene, any compound in which a low-molecular-weight organic compound self-organizes to form a highly ordered structure. However, the use of hydrogen bonding is not necessarily required, and there is no particular limitation as long as the molecules themselves have self-organizing properties and can form a film.

Materials with these self-assembly functions include, for example, compounds having the structures shown below, triptycene described in WO 2014/111980, WO 2014/125527, WO 2016/010061, etc. Derivatives can also self-assemble to form highly ordered films.

These compounds, like the hexa-2-pyridylbenzene mentioned above, are not particularly rigid in their molecules themselves. It can be used as a barrier film in the same way because it self-assembles to form a large domain when it is lost.

In addition, self-assembly is not a phenomenon that occurs only in the case of alkyl groups substituted as substituents, both in organic synthesis chemistry and structural chemistry, but it is possible to change the substituents as described later. It goes without saying that the present invention should not be limited to those exemplified so far, since it is considered that a similar self-assembled film is formed even in this case.
These compounds have hitherto been used as gate insulating films for transistors, but their use as barrier films in the present invention has not been disclosed at all. In the first place, the gate insulating film does not matter even if it has some surface defects or low density, and it is completely different from the quality required for the barrier film this time.

Schematic diagram showing an example of the inkjet printing method, which is a wet coating method that can be applied to form a barrier film. Schematic configuration diagram showing an example of the configuration of an organic electroluminescence device provided with a barrier film of the present invention. Schematic configuration diagram showing an example of another configuration of an organic electroluminescence device provided with a barrier film of the present invention. Schematic configuration diagram showing an example of the configuration of a solar cell equipped with the barrier film of the present invention. Schematic configuration diagram showing an example of the configuration of an evaluation sample produced in Example 2

The barrier film of the present invention is a barrier film against gases or liquids, and is characterized by being composed mainly of organic compound molecules having at least a self-filling structure. This feature is a technical feature common to or corresponding to each of the following embodiments.

As an embodiment of the present invention, the molecules of the organic compound having 3-fold, 4-fold or to 6-fold rotational symmetry cause more orderly self-assembly and more highly ordered low-molecular-weight organic compounds. It is preferable in that a barrier film can be formed from the compound.

In addition, in an X-ray diffraction spectrum obtained by fabricating a barrier film comprising molecules of the organic compound on a silicon wafer and measuring the barrier film by X-ray diffraction, the intensity of the highest peak is 500 counts or more, and It is preferable that the half-value width of the peak is 1.0 degree or less in that a barrier film can be formed from a highly ordered low-molecular-weight organic compound.

Further, it is preferable that the organic compound has a molecular weight of 1000 or less, in that the solubility in a solvent for preparing the barrier film-forming coating liquid can be sufficiently ensured.

In addition, it is preferable that the barrier film is a coating film and that the barrier film is formed by a wet coating method, because the coating film is excellent in uniformity and can be formed with simple manufacturing equipment.

Also, a barrier film laminate having a barrier property against gas or liquid, which has a structure in which at least the barrier film of the present invention and a different barrier film are laminated, and the different barrier film is made of an inorganic material. It is preferable in that a more dense gas barrier laminate can be obtained depending on the body and high resistance to stretching stress can be imparted.

In addition, the barrier film of the present invention can be applied to electronic devices, particularly electroluminescence elements, solar cells, semiconductors, LEDs, secondary batteries, etc., to reduce the influence of harmful gas components of the parts constituting the electronic device. It is preferable in that it is possible to prevent

DETAILED DESCRIPTION OF THE INVENTION The present invention, its constituent elements, and embodiments and modes for carrying out the present invention will be described in detail below. In the present application, "-" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.

《Barrier film》
The barrier film of the present invention is a barrier film against gases or liquids, and is characterized by being composed mainly of organic compound molecules having at least a self-filling structure.

The term "self-packing structure" as used in the present invention refers to a dense packing structure formed by regularly arranging and self-organizing molecules.

Further, the organic compound molecules have 3-fold, 4-fold or 6-fold rotational symmetry, a barrier film made of the organic compound molecules is prepared on a silicon wafer, and the barrier film is subjected to X-ray diffraction measurement. In the X-ray diffraction spectrum obtained by doing so, it is preferable that the intensity of the highest intensity peak is 500 counts or more and the half width of the peak is 1.0 degree or less.

As a method for confirming that the barrier film has a self-filling structure in the present invention, in the X-ray diffraction spectrum obtained by X-ray diffraction measurement of the barrier film, the intensity of the highest intensity peak is 500 counts or more, and the peak is 1.0 degree or less. In the present invention, a thin film single crystal analysis X-ray diffractometer "X'Pert ³ MRD XL" (manufactured by Malvern Panalytical) was used for the X-ray diffraction measurement.

Further, it is preferable that the molecules of the organic compound forming the barrier film of the present invention "have 3-fold, 4-fold or 6-fold rotational symmetry". "Rotationally symmetric" as used in the present invention refers to a structure that is indistinguishable before and after the structure is rotated. Rotational symmetry mainly includes 1-fold rotational symmetry to 6-fold rotational symmetry. It is expressed 6 times.

[Self-assembled membrane]
The details of the self-organization will be described below.

Self-organization in the present invention means that the molecules forming the coating film in a random state are removed from the film by volatile components constituting the film, such as solvents used for dilution and dissolution. It is to form an ordered structure in the process. In the present invention, relatively small molecules spontaneously aggregate to form a higher-order self-packing structure, which is defined as forming a thermodynamically stable self-packing structure.

In the present invention, the film formed mainly from organic compound molecules having at least a self-filling structure is, for example, degraded by harmful components, such as moisture and corrosive gases, to electronic parts constituting electronic devices. It is characterized by being a barrier film that prevents

A barrier film in the present invention is defined as a film having the following barrier properties.

The “barrier property” as used in the present invention means that the water vapor transmission rate (temperature: 60±0.5° C., relative humidity (RH): 90±2%) measured by a method conforming to JIS K 7129-1992 is 3. ×10 ⁻³ g/(m ² ·24h) or less, and the oxygen permeability measured by a method conforming to JIS K 7126-1987 is 1 × 10 ⁻³ mL/m ² ·24h·atm or less. means

[Constituent material for self-assembled membrane]
In the present invention, the organic compound to be applied to form the self-packing structure is not particularly limited as long as it can form a dense packing structure formed by regularly arranging and self-organizing molecules. However, hexa-2-pyridylbenzene having 3, 4 or 6-fold rotational symmetry (hereinafter referred to as abbreviated as "HPB") are preferred, and triptycene derivatives are also preferred.

In addition, it is preferable that the organic compound to be applied has a molecular weight of 1000 or less, in that the self-assembled film can be efficiently formed.

1) Hexaarylbenzene derivative A hexaarylbenzene derivative applicable to the present invention is a compound having a structure represented by the following general formula (1).

In the formula, R ₁ represents a substituent having a cyclic structure and n1 is 6. Each of the six R ₁ 's may be the same or different. When the six R ₁ have different structures, the substituents at the 1-, 3- and 5-positions and the substituents at the 2-, 4- and 6-positions respectively have the same structure.

A compound having a structure represented by general formula (1) has 3-fold or 6-fold symmetry.

Examples of typical substituents represented by R ₁ include those shown below.

- Aromatic hydrocarbon group (also called aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group, etc., e.g., phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group , azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.)
- Aromatic heterocyclic group (e.g., furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, diaza a carbazolyl group (a phthalazinyl group, etc., in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced with a nitrogen atom);
- Heterocyclic group (e.g., pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.)
- Aryloxy group (e.g., phenoxy group, naphthyloxy group, etc.)
- Arylthio group (e.g., phenylthio group, naphthylthio group, etc.)
- Aryloxycarbonyl group (e.g., phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.)
- Arylsulfonyl group or heteroarylsulfonyl group (e.g., phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.)
etc.

Substituents having specific cyclic structures are shown below.

Specific compounds of the hexaarylbenzene derivative include exemplary compounds 1 to 22 described later.

2) Triphenylene Derivatives In the present invention, triphenylene derivatives having three-fold symmetry can also be applied. As specific examples of compounds, Exemplary Compounds 24 to 26 described later can be mentioned.

上記一般式（２）においては、Ｒ_２、Ｒ_５及びＲ_８は、環状構造を有する置換基を表す。 3) Triarylborane Derivative In the present invention, a triarylborane derivative having a structure represented by the following general formula (2) with three-fold symmetry can also be applied.

In general formula (2) above, R ₂ , R ₅ and R ₈ represent substituents having a cyclic structure.

R ₃ , R ₄ , R ₆ , R ₇ , R ₉ and R ₁₀ each independently represent a hydrogen atom, chain alkyl group, alkoxy group, ester group or cyano group.

具体的な化合物例としては、後述の例示化合物２７～３１を挙げることができる。 Examples of substituents having a cyclic structure represented by R ₂ , R ₅ and R ₈ are shown below. * indicates the bonding position with the benzene ring.

Specific examples of the compounds include Exemplary Compounds 27 to 31 described later.

4) Triptycene Derivative A preferred example of the triptyne derivative is a triptyne derivative having a structure represented by the following general formula (3).

In the formula, R ¹ represents a saturated or unsaturated divalent hydrocarbon group having 2 to 60 carbon atoms, the hydrocarbon group may have one or more substituents, and One or two or more carbon atoms in the hydrocarbon group are an oxygen atom, a sulfur atom, a silicon atom, or —NR ⁵ — (wherein R ⁵ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, , or represents an aryl group having 6 to 30 carbon atoms.).

R ² represents a hydrogen atom or a saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; R ³ represents a group —R ¹ —Z, a hydrogen atom, or a saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; represents a hydrocarbon group.

Three ^R4 may be the same or different and each independently represents a hydrogen atom, a halogen atom, a hydroxy group, a nitro group, a cyano group, an amino group, a monoalkyl-substituted amino group, a dialkyl-substituted amino group, or a substituent. optionally substituted C 1-10 alkyl group, optionally substituted C 2-10 alkenyl group, optionally substituted C 2-10 alkynyl group, substituent An alkoxy group having 1 to 10 carbon atoms which may have a substituent, an alkylthio group having 1 to 10 carbon atoms which may have a substituent, a formyl group, an alkyl having 1 to 10 carbon atoms which may have a substituent carbonyl group, optionally substituted alkoxycarbonyl group having 1 to 10 carbon atoms, alkylcarbonyloxy group optionally having 1 to 10 carbon atoms, optionally substituted carbon number 6 to 30 aryl groups or 5 to 8-membered substituents having 1 to 5 heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur atoms and having 2 to 10 carbon atoms; represents a heteroaryl group which may be

X represents a linker group consisting of a divalent atomic group composed of 1 to 5 atoms selected from the group consisting of nitrogen, oxygen, sulfur, carbon and silicon atoms and hydrogen atoms.

Z is a hydrogen atom, a group capable of binding or adsorbing to the surface of a solid substrate; or 1 to 15 selected from the group consisting of a nitrogen atom, an oxygen atom, a sulfur atom, a carbon atom, a phosphorus atom, a halogen atom, and a silicon atom and a hydrogen atom.

Specific examples of tripsene derivatives having a structure represented by general formula (3) include exemplary compounds 33 to 36 described later.

For other exemplary compounds of tripsene derivatives applicable to the present invention and methods for synthesizing them, see, for example, the descriptions of WO2014/111980, WO2014/125527, WO2016/010061, and the like. can.

Compounds applicable to the formation of the self-filling structure described above are exemplified below, but the present invention is not limited to the compounds exemplified here.

[Synthesis of compound for forming self-filling structure]
In the present invention, the compound for forming a self-filling structure can be synthesized according to a conventionally known synthesis method.

An example of a representative method for synthesizing the compound for forming a self-filling structure according to the present invention is shown below.

上記合成スキームに従い、例示化合物１であるヘキサ－２－ピリジルベンゼンを合成することができる。 (Exemplary compound 1: Synthesis of hexa-2-pyridylbenzene)

Hexa-2-pyridylbenzene, Exemplary Compound 1, can be synthesized according to the above synthetic scheme.

0.155 g of 2-phenylpyridine, 0.908 g of 2-chloropyridine, 20.4 mg of pivalic acid, 0.636 g of sodium carbonate, and NMP (N- 5.0 mL of methyl-2-pyrrolidone) and 30.6 mg of [RuCl ₂ (η ⁶ -C ₆ H ₆ )] ₂ as a catalyst are added, and after nitrogen gas bubbling, the mixture is capped with a dedicated cap and attached to a microwave apparatus. The mixture was heated and stirred at 220° C. for 1 hour. After the reaction, the reaction mixture was cooled to room temperature, the NMP solvent was distilled off under reduced pressure, and purification was performed using a silica gel chromatogram to obtain 0.990 g (yield 93%) of Exemplary Compound 1, which is the desired product.

[X-ray diffraction spectrum characteristics of barrier film]
In the barrier film of the present invention, a barrier film comprising molecules of the organic compound of the present invention is formed on a silicon wafer, and the barrier film is subjected to X-ray diffraction measurement. is 500 counts or more, and the half width of the peak is preferably 1.0 degree or less.

In the present invention, for X-ray diffraction measurement, a thin-film single-crystal analysis X-ray diffractometer "X'Pert ³ MRD XL" (manufactured by Malvern Panalytical) is used according to the Out of Plsane measurement method (2θ/ω method). can be done.

[Formation of barrier film]
The barrier film of the present invention is prepared by dissolving a compound for forming a self-filling structure in an organic solvent capable of dissolving the compound to prepare a coating solution for forming a barrier film. A method of forming a single film, a method of forming a barrier film by providing a barrier film on a plastic substrate, or a method of applying it to an electronic component constituting an electronic device to form a barrier film (sealing layer). After coating, the organic solvent in the coating film is gradually removed in the drying process, causing regular self-organization and forming a barrier film that is a thin film of an ordered low-molecular-weight organic compound.

[Preparation of coating solution for forming barrier film]
In the present invention, a self-filling structure-forming compound is dissolved in an organic solvent capable of dissolving the compound to prepare a coating solution for forming a barrier film.

The solvent applicable to the preparation of the barrier film-forming coating solution is not particularly limited as long as it is an organic solvent capable of dissolving the compound for forming a self-filling structure according to the present invention. Examples include γ-butyrolactone and the like. Lactones; Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-amyl ketone, methyl isoamyl ketone, 2-heptanone; Monohydric alcohols such as methanol, ethanol, isopropanol; Ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol polyhydric alcohols and derivatives thereof; ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate and other glycol esters; monoethers or monoether esters such as ethyl ether, monopropyl ether, monobutyl ether; methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, Esters such as ethyl ethoxypropionate; anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, amylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. cyclic ethers such as dioxane and tetrahydrofuran (THF); amides such as dimethylformamide (DMF) and dimethylacetamide (DMA); sulfur-containing solvents such as dimethylsulfoxide (DMSO); can be mentioned. These organic solvents may be used alone or as a mixed solvent of two or more.

Preferred organic solvents include amides such as dimethylformamide (DMF) and dimethylacetamide (DMA), cyclic ethers such as dioxane and tetrahydrofuran (THF), and sulfur-containing solvents such as dimethylsulfoxide (DMSO). be done. Particularly preferred solvents include polar solvents such as dimethylformamide (DMF) and tetrahydrofuran (THF).

[Method for Forming Barrier Film]
The method for forming the barrier film of the present invention is not particularly limited. , is preferable in that it can cause self-organization and form a barrier film that is a thin film of an ordered low-molecular-weight organic compound.

Wet coating methods applicable to the present invention include an inkjet printing method, a spin coating method, a casting method, a screen printing method, a die coating method, a blade coating method, a roll coating method, a spray coating method, a curtain coating method, and an LB method ( Langmuir-Blodgett method), dispenser method, etc., and the wet coating method is preferably an inkjet printing method, a spin coating method or a dispenser method from the viewpoint of easy formation of a uniform thin film and high productivity. .

(Inkjet printing method)
In the method for producing a barrier film of the present invention, it is preferable to apply an inkjet printing method as a wet coating method.

The inkjet head used in the inkjet printing method, conditions for ejecting ink droplets, and the inkjet recording method will be described below with reference to the drawings.

<Inkjet head>
The inkjet head used in the inkjet printing method may be of the on-demand system or the continuous system. In addition, as a discharge method, an electro-mechanical conversion method (eg, single cavity type, double cavity type, bender type, piston type, share mode type, shared wall type, etc.), an electro-thermal conversion method (eg, thermal Specific examples include inkjet type, bubble jet (registered trademark) type, etc.), electrostatic attraction type (e.g., electric field control type, slit jet type, etc.), discharge type (e.g., spark jet type, etc.), and the like. However, any ejection method may be used. Moreover, as a printing method, a serial head method, a line head method, or the like can be used without limitation.

<Method of Forming Barrier Film>
There are one-pass printing method and multi-pass printing method in the barrier film forming method by the inkjet printing method. The one-pass printing method is a method in which a plurality of inkjet heads are fixedly arranged in a predetermined printing area and printed by one head scan. On the other hand, the multi-pass printing method (also called serial printing method) is a method of printing a predetermined print area by performing multiple head scans.

In the one-pass printing method, it is preferable to use a wide head in which nozzles are arranged over a width equal to or greater than the width of the desired coating pattern. When forming a plurality of independent coating patterns that are not continuous on the same base material, a wide head having at least the width of each coating pattern or more may be used.

FIG. 1 is a schematic diagram showing an example of a method of forming a barrier film using an inkjet printing method, which is a one-pass printing method.

FIG. 1 shows a barrier film having a barrier film 2 formed by ejecting ink composed of a coating liquid for forming a barrier film onto a flexible substrate F using an inkjet printer equipped with an inkjet head 30, for example. An example of how to form is shown.

As shown in FIG. 1, while the flexible base material F is continuously transported, the ink containing the coating liquid for forming the barrier film is sequentially ejected as ink droplets from the inkjet head 30 to form the barrier film 2 .

The inkjet head 30 that can be applied to the method for producing a barrier film of the present invention is not particularly limited. It may be a shear mode type (piezo type) head that ejects the ink liquid by change, or it has a heating element. A thermal type head that ejects liquid may also be used.

The ink jet head 30 is connected to a supply mechanism for ejecting ink liquid and the like. The ink liquid is supplied from the tank 38A. In this example, the liquid surface of the tank is kept constant so that the ink liquid pressure in the inkjet head 30 is always kept constant. As a method for this, the ink liquid is overflowed from the tank 38A and returned to the tank 38B by gravity flow. The supply of the ink liquid from the tank 38B to the tank 38A is performed by the pump 31, and is controlled so that the liquid level of the tank 38A is stably kept constant according to the ejection conditions.

Inkjet heads to which the present invention can be applied include, for example, JP-A-2012-140017, JP-A-2013-010227, JP-A-2014-058171, JP-A-2014-097644, and JP-A-2015-142979. Publications, JP-A-2015-142980, JP-A-2016-002675, JP-A-2016-002682, JP-A-2016-107401, JP-A-2017-109476, JP-A-2017-177626, etc. can be appropriately selected and applied.

(Spin coating method)
In the present invention, a spin coating method can be mentioned as another example of the wet coating method. The spin coating method is a method of forming a barrier film by centrifugal force by rotating a smooth base material at high speed. The main method is to form a barrier film by a single wafer, and the productivity is slightly lower than that of the inkjet printing method.

(dispenser method)
The dispenser method is a method in which a barrier film-forming coating liquid is placed in a container having a nozzle or needle hole, and pressure is applied to the container to extrude the barrier film-forming coating liquid to form a barrier film.

《Barrier film laminate》
The barrier film laminate of the present invention has a structure in which the barrier film of the present invention and a different barrier film are laminated, and the different barrier film is made of an inorganic material.

[Another kind of barrier film]
Another type of barrier film laminated with the barrier film of the present invention is characterized by being composed of an inorganic material.

Other types of barrier films composed of inorganic materials applicable to the present invention include metal oxides, metal oxynitrides or metal nitrides such as silicon oxide, titanium oxide, indium oxide, tin oxide, indium - Metal oxides such as tin oxide (ITO) and aluminum oxide, metal nitrides such as silicon nitride, and metal oxynitrides such as silicon oxynitride and titanium oxynitride.

The method for forming the barrier film composed of the inorganic material is not particularly limited, and any method may be used. Examples include vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, A plating method, a plasma polymerization method, an atmospheric pressure plasma polymerization method, a CVD method (for example, a plasma CVD method, a laser CVD method, a thermal CVD method, etc.), a wet coating method, a sol-gel method, or the like can be used.

《Barrier film》
The barrier film of the present invention can be formed on a flexible substrate to form a barrier film (hereinafter also referred to as a gas barrier film).

The flexible substrate applicable to the formation of the barrier film is not particularly limited. TAC), cellulose acetate butyrate, cellulose acetate propionate (CAP), cellulose acetate phthalate, cellulose esters such as cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, Polycarbonate, norbornene resin, polymethylpentene, polyetherketone, polyimide, polyethersulfone (PES), polyphenylene sulfide, polysulfones, polyetherimide, polyetherketoneimide, polyamide, fluorine resin, nylon, polymethylmethacrylate, acrylic or Examples include polyarylates, organic-inorganic hybrid resins, and the like.

《Application of Barrier Film: Application to Electronic Devices》
The barrier film of the present invention is characterized by being applied to electronic devices. Preferred examples of electronic devices to which the barrier film of the present invention is applied include organic electroluminescence elements, solar cells, semiconductors, LEDs, secondary batteries, and liquid crystal displays. Application examples to luminescence elements and solar cells will be described.

[Example 1 of application to organic EL device]
[Basic configuration of organic EL element]
First, the basic configuration of an organic EL element to which the barrier film of the present invention is applied will be described with reference to the drawings.

FIG. 2 shows a schematic configuration diagram of an example of the configuration of an organic electroluminescence device provided with the barrier film of the present invention.

The organic EL 1 shown in FIG. 2 has a barrier film 2 of the present invention formed on the entire surface of a flexible substrate F, and thereon a first electrode 4 (anode), an organic functional layer group 6 including a light emitting layer, a second An electrode 7 (cathode) is laminated, and after sealing the peripheral portion of the barrier film laminate with a first sealing layer 8, the entire surface of the organic EL element 1 is covered with a second sealing layer 9. .

Generally applied flexible base material F has a relatively high moisture permeability, and the inside of the flexible base material may contain moisture, so water vapor, oxygen, harmful gases, etc. As a result, the organic functional layer group 6 and the like configured above are damaged. Improve the durability of the device.

[Main constituent materials of organic EL elements]
The details of the constituent layers except for the barrier film, which has already been described in detail, in the main structure of the organic EL element described with reference to FIG. 2 will be described.

(Base material)
In the present invention, the flexible substrate F that can be applied to the organic EL element may be a substrate having flexibility, such as thin glass, resin film, metal foil, fabric (eg, cloth, textile, etc.). , paper, elastomer (rubber cloth), etc., and may be transparent or opaque.

When the organic EL element EL is of a bottom emission type in which emitted light is extracted from the flexible substrate F side, the flexible substrate F is preferably light-transmitting. Being light-transmitting means that the total light transmittance in the visible light region is 20% or more, preferably 50% or more, and more preferably 80% or more. preferable. A particularly preferable flexible base material F is a resin film capable of imparting flexibility to the organic EL element.

Examples of resin films include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, cellulose nitrate, or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol (PVA), polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate (PC), norbornene resin, polymethylpentene , polyetherketone, polyimide (PI), polyethersulfone (PES), polyphenylene sulfide, polysulfones, polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate (PMMA), acrylic or polyarylate and cycloolefin resins such as ARTON (trade name, manufactured by JSR) and APEL (trade name, manufactured by Mitsui Chemicals, Inc.).

A flexible base material can be used individually or in combination of 2 or more types. When the flexible substrate has a laminated structure of two or more layers, each substrate may be of the same type or of different types. Moreover, the structure which can peel and isolate|separate after manufacturing an organic EL element may be sufficient.

The surface of the flexible base material F may be subjected to a surface activation treatment or may be provided with a base layer in order to enhance adhesion with the barrier film 2 formed on the flexible base material. Moreover, a hard coat layer may be provided in order to improve the impact resistance.

Examples of surface activation treatment include corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, and laser treatment.

Materials for the undercoat layer and the hard coat layer include polyester, polyamide, polyurethane, vinyl copolymer, butadiene copolymer, acrylic copolymer, vinylidene copolymer, epoxy copolymer, and the like. Among them, an ultraviolet curable resin can be preferably used. The underlayer may be a single layer, but if it has a multi-layer structure, the adhesion is further improved. A commercially available plastic substrate on which a hard coat layer is formed in advance may be used, or a base layer or hard coat layer may be provided by coating and curing only the necessary portions of the flexible substrate.

(anode)
As the anode of the organic EL element, an electrode material having a large work function (4 eV or more), a metal, an alloy, an electrically conductive compound of a metal, or a mixture thereof is preferably used.

Here, the term "electrically conductive compound of a metal" refers to a compound of a metal and another substance that has electrical conductivity. Specifically, examples thereof include metal oxides and halides. It means a material that has electrical conductivity.

Specific examples of such electrode materials include metals such as Au, conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ and ZnO. The anode can be produced by forming a thin film made of these electrode materials on the substrate by a known method such as vapor deposition or sputtering.

In addition, a pattern of a desired shape may be formed on this thin film by photolithography, and if pattern accuracy is not required (approximately 100 μm or more), a desired shape may be formed during vapor deposition or sputtering of the electrode material. A pattern may be formed through a mask.

When light is extracted from the anode, the light transmittance is desirably greater than 10%. Moreover, the sheet resistance as an anode is several hundred Ω/sq. The following are preferred. Furthermore, the film thickness of the anode is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm, depending on the constituent material.

(Organic functional layer group)
The group of organic functional layers includes at least a light-emitting layer. In a broad sense, the light-emitting layer refers to a layer that emits light when a current is passed through an electrode consisting of a cathode and an anode. and an anode.

The organic EL device used in the present invention may optionally have a hole injection layer, an electron injection layer, a hole transport layer and an electron transport layer in addition to the light emitting layer. and the anode.

in particular,
(i) anode/light emitting layer/cathode (ii) anode/hole injection layer/light emitting layer/cathode (iii) anode/light emitting layer/electron injection layer/cathode (iv) anode/hole injection layer/light emitting layer/electron injection layer/cathode (v) anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/electron injection layer/cathode (vi) anode/hole transport layer/light emitting layer/electron transport layer/cathode etc. structure.

In each organic functional layer group according to the present invention, there are no particular limitations on specific configurations, formation methods, and the like, and known configurations, materials, and formation methods can be applied. For example, paragraph numbers [0014] to [0121] of JP-A-2013-089608, paragraph numbers [0065] to [0262] of JP-A-2014-120334, paragraph numbers of JP-A-2015-201508 [0044] to [0118] can be referred to.

<Light emitting layer>
The light-emitting layer is a layer that emits light by recombination of electrons and holes injected from an electrode, an electron-transporting layer, or a hole-transporting layer. It may be an interface with an adjacent layer. The light-emitting layer may be a layer having a single composition, or may have a laminated structure consisting of a plurality of layers having the same or different compositions.

Functions such as a hole injection layer, an electron injection layer, a hole transport layer and an electron transport layer may be imparted to the light emitting layer itself. That is, the light emitting layer has (1) an injection function capable of injecting holes from the anode or the hole injection layer and electrons from the cathode or the electron injection layer when an electric field is applied; At least one of the transport function of moving charges (electrons and holes) by the force of an electric field, and (3) the light-emitting function of providing a field for recombination of electrons and holes inside the light-emitting layer, leading to light emission. You can give it a function. Note that the light-emitting layer may have a difference in the easiness of hole injection and the easiness of electron injection, and the transport function represented by the mobility of holes and electrons may be different. , preferably have a function of transferring the charge of at least one of them.

The type of luminescent material used in the luminescent layer is not particularly limited, and conventionally known luminescent materials for organic EL devices can be used. Such luminescent materials are mainly organic compounds, and depending on the desired color tone, for example, Macromol. Symp. 125, pp. 17-26. Further, the light-emitting material may be a polymer material such as p-polyphenylenevinylene or polyfluorene, and a polymer material having the above-mentioned light-emitting material introduced into the side chain or a polymer material having the above-mentioned light-emitting material as the main chain of the polymer. may be used. As described above, the light emitting material may have a hole injection function and an electron injection function in addition to the light emitting performance. Available.

In the layers constituting the organic EL element, when the layer is composed of two or more organic compounds, the main component is called the host, and the other components are called the dopant. The mixing ratio of the light-emitting layer dopant (hereinafter also referred to as light-emitting dopant) to the host compound is preferably 0.1 to less than 30% by mass.

Dopants used in the light-emitting layer are roughly classified into two types: a fluorescent dopant that emits fluorescence and a phosphorescent dopant that emits phosphorescence.

Representative examples of fluorescent dopants include coumarin-based dyes, pyran-based dyes, cyanine-based dyes, croconium-based dyes, squarium-based dyes, oxobenzanthracene-based dyes, fluorescein-based dyes, rhodamine-based dyes, pyrylium-based dyes, and perylene-based dyes. , stilbene dyes, polythiophene dyes, rare earth complex phosphors, and other known fluorescent compounds.

In the present invention, at least one light-emitting layer preferably contains a phosphorescent compound.

In the present invention, the phosphorescent compound is a compound that emits light from an excited triplet and has a phosphorescent quantum yield of 0.001 or more at 25°C.

The phosphorescence quantum yield is preferably 0.01 or more, more preferably 0.1 or more. The phosphorescence quantum yield can be measured by the method described in Experimental Chemistry Course 7, 4th Edition, Spectroscopy II, page 398 (1992 edition, Maruzen). Phosphorescence quantum yield in a solution can be measured using various solvents, and the phosphorescent compound used in the present invention may achieve the above phosphorescence quantum yield in any solvent.

The phosphorescent dopant is a phosphorescent compound, and representative examples thereof are preferably complex compounds containing metals of groups 8 to 10 in the periodic table of the elements, and more preferably iridium compounds and osmium compounds. , rhodium compounds, palladium compounds, or platinum compounds (platinum complex compounds), preferably iridium compounds, rhodium compounds, and platinum compounds, and most preferably iridium compounds.

Examples of dopants are the compounds described in the following documents or patent publications. J. Am. Chem. Soc. Vol. 123, pp. 4304-4312, WO 2000/70655, WO 2001/93642, WO 2002/02714, WO 2002/15645, WO 2002/44189, WO 2002/081488, JP 2002-280178 No. 2001-181616, 2002-280179, 2001-181617, 2002-280180, 2001-247859, 2002-299060, 2001-313178 Publications, 2002-302671, 2001-345183, 2002-324679, 2002-332291, 2002-50484, 2002-332292, 2002-83684 , JP-A-2002-540572, JP-A-2002-117978, JP-A-2002-338588, JP-A-2002-170684, JP-A-2002-352960, JP-A-2002-50483, JP-A-2002-100476 Publications, No. 2002-173674, No. 2002-359082, No. 2002-175884, No. 2002-363552, No. 2002-184582, No. 2003-7469, No. 2002-525808 Publications, JP 2003-7471, JP 2002-525833, JP 2003-31366, 2002-226495, 2002-234894, 2002-235076, 2002- 241751, 2001-319779, 2001-319780, 2002-62824, 2002-100474, 2002-203679, 2002-343572, 2002-203678 publication, etc.

Only one light-emitting dopant may be used, or a plurality of light-emitting dopants may be used. By extracting light emitted from these dopants at the same time, a light-emitting device having a plurality of maximum emission wavelengths can be constructed. Also, for example, both a phosphorescent dopant and a fluorescent dopant may be added. When constructing an organic EL device by laminating a plurality of light-emitting layers, the light-emitting dopant contained in each layer may be the same or different, and may be of a single type or a plurality of types. .

Furthermore, a polymer material may be used in which the light-emitting dopant is introduced into the polymer chain, or the light-emitting dopant is used as the main chain of the polymer.

Examples of the host compound include those having a basic skeleton such as carbazole derivatives, triarylamine derivatives, aromatic borane derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, and oligoarylene compounds. Transport materials and hole transport materials are also suitable examples.

When applied to blue or white light emitting devices, display devices and lighting devices, the maximum fluorescence wavelength of the host compound is preferably 415 nm or less, and when using a phosphorescent dopant, the phosphorescence of the host compound is 0- More preferably, the 0 band is 450 nm or less. As the light-emitting host, a compound that has a hole-transporting ability and an electron-transporting ability, prevents emission from becoming longer in wavelength, and has a high Tg (glass transition temperature) is preferable.

As specific examples of the luminescent host, the compounds described in the following documents are suitable.

JP 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357977, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227, 2002-231453, 2003 -3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, 2002-299060, 2002- 302516, 2002-305083, 2002-305084, 2002-308837 and the like.

The emissive dopant may be dispersed throughout or partially in the layer containing the host compound. A compound having another function may be added to the light-emitting layer.

Using the above materials, for example, a vapor deposition method, a spin coating method, a casting method, an LB method (Langmuir-Blodgett method), an inkjet printing method, a printing method, or the like is used to form a thin film by a known method, thereby forming a light-emitting layer. Although it can be formed, the light-emitting layer formed is preferably a molecular deposition film.

Here, the term "molecule deposition film" refers to a thin film formed by depositing the compound from the vapor phase state, or a film formed by solidifying the compound from the molten state or liquid phase state. Generally, this molecular deposition film and a thin film (molecule accumulation film) formed by the LB method can be distinguished from each other by differences in aggregation structure and higher-order structure, and functional differences resulting therefrom.

In the present invention, it is preferable to use the phosphorescent dopant and the host compound, which are the light-emitting materials, as the organic material for the electronic device of the present invention. That is, the light emitting layer is formed by spin coating, casting, ink jetting, spraying, or printing a solution containing the phosphorescent dopant and host compound, an organic solvent, and cellulose nanofibers (composition for electronic device production). It is preferable to form the layer by coating method, slot type coater method, or the like, because it is possible to form a light-emitting layer composed of a molecular deposition film. Among them, the inkjet printing method is preferable from the viewpoints that a homogeneous film can be easily obtained and that pinholes are difficult to form.

Then, in the coating liquid containing the phosphorescent dopant and the host compound, the organic solvent, and the cellulose nanofibers, the dissolved carbon dioxide concentration in the organic solvent under atmospheric pressure conditions at 50 ° C. or less is 1 ppm to saturation with respect to the organic solvent. Concentration is preferred. As a means for adjusting the dissolved carbon dioxide concentration to the above range, a method of bubbling carbon dioxide gas into a solution containing a phosphorescent dopant and a host compound and an organic solvent, or a supercritical fluid containing an organic solvent and carbon dioxide is used. and the supercritical chromatography method used.

<Hole injection layer and hole transport layer>
The hole injection material used for the hole injection layer has either hole injection or electron blocking properties. Further, the hole-transporting material used for the hole-transporting layer has an electron blocking property and also has a function of transporting holes to the light-emitting layer. Therefore, in the present invention, the hole transport layer is included in the hole injection layer.

These hole injection materials and hole transport materials may be either organic or inorganic. Specific examples include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives. , hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, porphyrin compounds and thiophene oligomers. Among these, arylamine derivatives and porphyrin compounds are preferred.

Among the arylamine derivatives, aromatic tertiary amine compounds and styrylamine compounds are preferred, and aromatic tertiary amine compounds are more preferred.

Representative examples of the aromatic tertiary amine compounds and styrylamine compounds include N,N,N',N'-tetraphenyl-4,4'-diaminophenyl; N,N'-diphenyl-N,N' -bis(3-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine (TPD); 2,2-bis(4-di-p-tolylaminophenyl)propane; 1,1- Bis(4-di-p-tolylaminophenyl)cyclohexane; N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl; 1,1-bis(4-di-p- tolylaminophenyl)-4-phenylcyclohexane; bis(4-dimethylamino-2-methylphenyl)phenylmethane; bis(4-di-p-tolylaminophenyl)phenylmethane; N,N'-diphenyl-N,N '-di(4-methoxyphenyl)-4,4'-diaminobiphenyl; N,N,N',N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis(diphenylamino)biphenyl ; N,N,N-tri(p-tolyl)amine; 4-(di-p-tolylamino)-4'-[4-(di-p-tolylamino)styryl]stilbene; 4-N,N-diphenylamino -(2-diphenylvinyl)benzene; 3-methoxy-4'-N,N-diphenylaminostilbene; N-phenylcarbazole, as well as two fused aromatics described in US Pat. No. 5,061,569. Those having a ring in the molecule, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (hereinafter abbreviated as α-NPD), described in JP-A-4-308688 and 4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (MTDATA) in which three triphenylamine units are linked in a starburst configuration. Inorganic compounds such as p-type-Si and p-type-SiC can also be used as hole injection materials.

Further, in the present invention, the hole-transporting material of the hole-transporting layer preferably has a fluorescence maximum wavelength of 415 nm or less. That is, the hole-transporting material is preferably a compound that has a hole-transporting ability, prevents emission from becoming longer in wavelength, and has a high Tg.

The hole injection layer and the hole transport layer are formed by applying the above hole injection material and hole transport material to a known method such as a vacuum vapor deposition method, a spin coating method, a casting method, an LB method, an inkjet printing method, a printing method, and the like. It can be formed by thinning according to the method.

In the present invention, the hole injection material and the hole transport material are preferably used as the organic material for the electronic device of the present invention. Then, a solution (composition for electronic device fabrication) containing the hole injection material and the hole transport material, an organic solvent, and cellulose nanofibers is applied by a spin coating method, a casting method, an ink jet method, a spray method, a printing method, It is preferably formed by application such as a slot type coater method. Among them, the inkjet printing method is preferable from the viewpoints that a homogeneous film can be easily obtained and pinholes are difficult to form.

The thicknesses of the hole injection layer and the hole transport layer are not particularly limited, but are usually about 5 nm to 5 μm. The hole injection layer and the hole transport layer may each have a one-layer structure composed of one or more of the materials described above, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions. good too. When both the hole injection layer and the hole transport layer are provided, usually different materials are used among the above materials, but the same material may be used.

<Electron injection layer and electron transport layer>
The electron injection layer only needs to have a function of transferring electrons injected from the cathode to the light-emitting layer, and any material can be selected and used from conventionally known compounds.

Examples of materials used for this electron injection layer (hereinafter also referred to as electron injection materials) include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic acid anhydrides such as naphthalene perylene, and carbodiimides. , frelenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like.

In addition, a series of electron transfer compounds described in JP-A-59-194393 are disclosed as materials for forming a light-emitting layer in the publication, but as a result of investigations by the present inventors, electron injection It turned out that it can be used as a material. Furthermore, among the above oxadiazole derivatives, a thiadiazole derivative in which an oxygen atom in the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as the electron injection material.

Also, metal complexes of 8-quinolinol derivatives such as tris(8-quinolinol)aluminum (abbreviated as Alq ₃ ), tris(5,7-dichloro-8-quinolinol)aluminum, tris(5,7-dibromo-8- quinolinol)aluminum, tris(2-methyl-8-quinolinol)aluminum, tris(5-methyl-8-quinolinol)aluminum, bis(8-quinolinol)zinc (Znq), etc., and the central metal of these metal complexes is In , Mg, Cu, Ca, Sn, Ga or Pb can also be used as the electron injection material.

In addition, metal-free materials, metal phthalocyanines, and those whose terminals are substituted with alkyl groups, sulfonic acid groups, or the like can also be preferably used as electron injection materials. Inorganic semiconductors such as n-type Si and n-type SiC can also be used as the electron injection material in the same manner as the hole injection layer.

A preferred compound used in the electron transport layer preferably has a fluorescence maximum wavelength of 415 nm or less. That is, the compound used in the electron transport layer is preferably a compound that has an electron transport ability, prevents emission from becoming longer in wavelength, and has a high Tg.

The electron injection layer is formed by thinning the electron injection material by a known method such as a vacuum vapor deposition method, a spin coating method, a casting method, a LB method, an inkjet method, a printing method, or a printing method. can be done.

In the present invention, the electron injection material is preferably used as the organic material for the electronic device of the present invention. Then, a solution (composition for electronic device fabrication) containing the electron injection material, an organic solvent, and cellulose nanofibers is applied by a spin coating method, a casting method, an inkjet method, a spray method, a printing method, a slot type coater method, or the like. It is preferably formed by coating. Among them, the inkjet method is preferable from the viewpoints that a homogeneous film can be easily obtained and pinholes are less likely to be generated.

Although the thickness of the electron injection layer is not particularly limited, it is usually selected within the range of 5 nm to 5 μm. This electron injection layer may have a one-layer structure consisting of one or two or more of these electron injection materials, or may have a laminated structure consisting of a plurality of layers having the same composition or different compositions.

In this specification, among the electron injection layers, when the ionization energy is higher than that of the light emitting layer, the electron injection layer is particularly called an electron transport layer. Therefore, in this specification, the electron transport layer is included in the electron injection layer.

The electron transport layer is also referred to as a hole blocking layer (hole blocking layer). , and those described in "Organic EL element and the front line of its industrialization" (published by NTS on November 30, 1998), page 237, and the like. In particular, in a so-called "phosphorescent light-emitting device" using an ortho-metal complex dopant in the light-emitting layer, it is preferable to adopt a structure having an electron transport layer (hole blocking layer) as in the above (v) and (vi).

(buffer layer)
A buffer layer (electrode interface layer) may be present between the anode and the light-emitting layer or hole-injection layer and between the cathode and the light-emitting layer or electron-injection layer.

A buffer layer is a layer provided between an electrode and an organic layer to reduce driving voltage and improve luminous efficiency. )”, Volume 2, Chapter 2 “Electrode Materials” (pages 123 to 166), which includes an anode buffer layer and a cathode buffer layer.

The details of the anode buffer layer are also described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069, etc. A specific example is a phthalocyanine buffer layer represented by copper phthalocyanine. , an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

The cathode buffer layer is described in detail in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, etc. Specifically, a metal buffer layer represented by strontium, aluminum, etc., Alkali metal compound buffer layers typified by lithium fluoride, alkaline earth metal compound buffer layers typified by magnesium fluoride, oxide buffer layers typified by aluminum oxide, and the like can be mentioned.

The buffer layer is desirably a very thin film, and although it depends on the material, its thickness is preferably in the range of 0.1 to 100 nm. Furthermore, in addition to the basic constituent layers described above, layers having other functions may be appropriately laminated as necessary.

(cathode)
As described above, the cathode of the organic EL element is generally made of a metal having a small work function (less than 4 eV) (hereinafter referred to as an electron-injecting metal), an alloy, an electrically conductive compound of the metal, or a mixture thereof. things are used.

Specific examples of such electrode materials include sodium, magnesium, lithium, aluminum, indium, rare earth metals, sodium-potassium alloys, magnesium/copper mixtures, magnesium/silver mixtures, magnesium/aluminum mixtures, magnesium/indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, lithium/aluminum mixture, and the like.

In the present invention, the materials listed above may be used as the electrode material for the cathode, but the cathode preferably contains a Group 13 metal element. That is, in the present invention, as will be described later, the surface of the cathode is oxidized with oxygen gas in a plasma state to form an oxide film on the surface of the cathode, thereby preventing further oxidation of the cathode and improving the durability of the cathode. can be made

Therefore, as the electrode material for the cathode, it is preferable to use a metal that has the favorable electron injection properties required for the cathode and that is capable of forming a dense oxide film.

Specific examples of the cathode electrode material containing the Group 13 metal element include aluminum, indium, magnesium/aluminum mixture, magnesium/indium mixture, and aluminum/aluminum oxide (Al ₂ O ₃ ) mixture. , lithium/aluminum mixtures, and the like. As for the mixing ratio of each component of the above mixture, a conventionally known ratio for a cathode of an organic EL element can be adopted, but the ratio is not particularly limited to this. The cathode can be produced by forming a thin film of the electrode material on the organic compound layer (organic EL layer) by a method such as vapor deposition or sputtering.

Moreover, the sheet resistance as a cathode is several hundred Ω/sq. The following is preferable, and the film thickness is usually selected in the range of 10 nm to 1 μm, preferably 50 to 200 nm. In order to transmit the emitted light, it is preferable to make either the anode or the cathode of the organic EL element transparent or semi-transparent, because the luminous efficiency is improved.

(sealing layer)
In the present invention, the peripheral portion of the organic EL unit from the anode (first electrode) to the cathode (second electrode) constituting the organic EL element is formed with a sealing layer to form a sealing structure.

As the constituent material and formation method of the sealing layer, the materials such as the silicon-containing polymer described in the formation of the gas barrier film and the formation method thereof can be similarly applied.

The sealing layer according to the present invention preferably comprises a first sealing layer 8 and a second sealing layer 9 as shown in FIG. The first sealing layer 8 and the second sealing layer 9 may be made of the same material or may be made of different materials.

For example, a method of forming the first sealing layer 8 with polydimethylsiloxane (abbreviation: PDMS) and forming the second sealing layer with perhydropolysilazane (abbreviation: PHPS) can be given as an example.

[Example 2 of application to organic EL device]
The organic EL element shown in FIG. 3 has the same basic configuration as that of the application example 1 described above, such as the electrodes and the organic functional layer group. It is also a preferred embodiment of the present invention to use the base material G and seal with a gas barrier film in which the barrier film 2 of the present invention is provided on a plastic base material F as a sealing member on the outermost surface.

[Application to solar cells]
Next, the configuration of a solar cell to which the barrier film of the present invention can be applied will be described with reference to the drawings.

[Basic configuration of solar cell]
FIG. 4 shows a schematic configuration diagram of an example of the configuration of a solar cell equipped with the barrier film of the present invention.

A solar cell to which the barrier film of the present invention can be applied is a solar cell comprising at least a first substrate, a first electrode, an organic photoelectric conversion unit, a second electrode, and a second substrate. It is preferably provided between the first substrate and the second substrate, more specifically, between the first substrate and the first electrode.

As shown in FIG. 4, the basic configuration of the solar cell 50 includes at least a first substrate 52, a first electrode 54, a photoelectric conversion unit 57 comprising a hole transport layer 55 and an electron transport layer 56, and a second electrode 58. , a sealing layer 59 , an adhesive layer 60 , and a second substrate 63 composed of Alpet AP consisting of an aluminum foil 61 and a PET film 62 .

Furthermore, as shown in FIG. 4, between the first substrate 52 and the first electrode 54, a barrier film 53 of the present invention and a different barrier film 64 having a different structure from the barrier film 53 are laminated thereon. is provided. The constituent material of the Maria film 64 is preferably an inorganic material such as a metal oxide.

[Constituent Elements of Solar Cell]
(First substrate)
As the first substrate, a synthetic resin, glass, or the like can be used as long as it has strength, durability, and light transmittance. Examples of synthetic resins include thermoplastic resins such as polyethylene naphthalate (PEN) film, polyethylene terephthalate (PET), polyesters, polycarbonates, polyolefins, polyimides, and fluorine resins. From the viewpoint of strength, durability, cost, etc., it is preferable to use a glass substrate.

As the first substrate, metal foil can be used in addition to the base material described above. The metal foil may serve as one electrode of the flexible solar cell as well as a substrate.

The metal constituting the metal foil is not particularly limited, and preferably has excellent durability and conductivity that can be used as an electrode. For example, metals such as aluminum, titanium, copper, and gold, and stainless steel Alloys such as steel (SUS) can be used. These materials may be used alone, or two or more of them may be used in combination.

Among others, the metal forming the metal foil preferably contains stainless steel (SUS). By using stainless steel (SUS) as the metal constituting the metal foil, the metal foil becomes tough and has improved resistance to bending, so variations in photoelectric conversion efficiency due to bending deformation can be suppressed. It is also preferable that the metal constituting the metal foil contains aluminum. By using aluminum as the metal constituting the metal foil, the difference in linear expansion coefficient between the metal foil and the photoelectric conversion layer containing the organic-inorganic perovskite compound is reduced, thereby further suppressing the occurrence of distortion during annealing. be able to.

The thickness of the metal foil is not particularly limited, but the preferred lower limit is 5 μm and the preferred upper limit is 500 μm. If the thickness of the metal foil is 5 μm or more, the resulting flexible solar cell has sufficient mechanical strength and is easy to handle. improves. A more preferable lower limit of the thickness of the metal foil is 10 μm, and a more preferable upper limit thereof is 100 μm.

(first electrode)
It is preferable to use a transparent electrode as the first electrode. Materials for the transparent conductive layer 3 constituting the transparent electrode include, for example, tin-added indium oxide (ITO), fluorine-added tin oxide (FTO), tin oxide (SnO ₂ ), indium zinc oxide (IZO), zinc oxide (ZnO), and polymeric materials with high electrical conductivity.

Examples of polymer materials include polyacetylene-based, polypyrrole-based, polythiophene-based, and polyphenylenevinylene-based polymer materials. A carbon-based thin film having high conductivity can also be used. Examples of the method for forming the transparent electrode include a sputtering method, a vapor deposition method, and a method of applying a dispersion.

(Organic photoelectric conversion unit)
In the present invention, the “organic photoelectric conversion unit” has a function of absorbing light to generate electrons and holes, and includes a hole transport layer, a photoelectric conversion layer, an electron transport layer, a mixed layer, a charge blocking layer, a It refers to a single layer structure or multilayer structure laminate containing an organic compound in any one of various functional layers such as a charge injection layer and an exciton diffusion prevention layer, and corresponds to a so-called bulk hetero layer.

A solar cell may have a so-called tandem structure, in which a plurality of pairs of hole transport layers and electron transport layers are provided. A tandem-type device is particularly preferable because of its high open-circuit voltage and high conversion efficiency. In that case, a recombination layer is arranged as an intermediate layer. That is, as a typical example of a tandem-type element, a configuration of positive electrode/hole transport layer/electron transport layer/hole transport layer/electron transport layer/metal oxide layer/negative electrode is exemplified.

In the present invention, in addition to the functional layers described above, other constituent layers may be provided as necessary.

Other constituent layers can also be preferably formed by any of dry film-forming methods such as vapor deposition and sputtering, transfer methods, printing methods, and the like.

The main functional layers are described below.

<1> Hole transport layer The hole transport layer is a layer having a function of receiving and transporting holes to the positive electrode or the positive electrode side.

The hole transport layer may be a single layer or a laminate of multiple layers. At least one layer of the hole transport layer preferably has a charge generating ability of absorbing light and generating electrons and holes. The hole transport layer can be formed using one or more hole transport materials.

Examples of the hole-transporting material include carbazole derivatives, polyarylalkane derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, and aromatic derivatives. Tertiary amine compounds, styrylamine compounds, aromatic dimethylidine compounds, porphyrin compounds, phthalocyanine compounds, polythiophene derivatives, polypyrrole derivatives, polyparaphenylene vinylene derivatives, and the like.

As a hole transport material, Chem. Rev. 2007, 107, 953-1010 as Hole Transport material.

Examples of the material for the hole transport layer having the ability to generate charge include porphyrin-based compounds, phthalocyanine-based compounds, polythiophene derivatives, polypyrrole derivatives, and polyparaphenylene vinylene derivatives. Rev. 1993, 93, 449-406.

Methods for forming the hole transport layer include a solvent coating method, a vacuum deposition method, and the like. Examples of solvent coating methods include spin coating, spray coating, bar coating, and die coating.

The thickness of the hole transport layer is preferably in the range of 1 to 500 nm, more preferably in the range of 2 to 200 nm, even more preferably in the range of 5 to 100 nm. The hole-transporting layer may have a single-layer structure composed of one or more of the materials described above, or may have a multilayer structure composed of multiple layers having the same composition or different compositions.

<2> Electron Transport Layer The electron transport layer is a layer having a function of transporting electrons to the negative electrode or the negative electrode side.

The electron transport layer may be a single layer or a laminate of multiple layers. At least one layer of the electron-transporting layer preferably has a charge generating ability of absorbing light and generating charges. The electron transport layer can be formed using one or more electron transport materials.

Examples of the electron transport material include fullerene derivatives, paraphenylene vinylene derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, phenanthroline derivatives, imidazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thio Pyrandioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, aromatic ring tetracarboxylic acid anhydrides such as naphthalene and perylene, imides and heterocycles derived from these, metals of 8-quinolinol derivatives complexes, various metal complexes represented by metal complexes having benzoxazole or benzothiazole as a ligand, organic silane derivatives, and the like.

Materials for the electron-transporting layer capable of generating charges include imides and heterocycles derived from fullerenes, polyparaphenylenevinylene derivatives, and perylenetetracarboxylic acid anhydrides. Examples thereof include Chem. Rev. 2007, 107, 953-1010 as Electron Transport Materials.

Methods for forming the electron transport layer include a solvent coating method, a vacuum deposition method, and the like.

The thickness of the electron transport layer is preferably in the range of 1 to 500 nm, more preferably in the range of 2 to 200 nm, even more preferably in the range of 5 to 100 nm. The electron transport layer may have a single-layer structure composed of one or more of the materials described above, or may have a multilayer structure composed of multiple layers having the same composition or different compositions.

(Second electrode)
Examples of the second electrode according to the present invention include oxide electrodes such as ITO, IZO, IWZO, ITZO, AZO, BZO, GZO, ZnO, and _SnO2 , Au, Ag, Ti, Zn, Mo, Ta, AgNW, Examples include thin film metals such as Na, NaK, Li, Mg, Al, MgAg, MgIn, AlLi, and CuI, metal compounds, and organic metals. Lamination of a combination of two or more types may also be possible.

In addition, examples of the method of forming the second electrode include a forming method using a CVD method, sputtering, vapor deposition, coating, and the like. The film thickness is not limited as long as it does not transmit light.

(sealing layer)
By covering the solar cell of the present invention with a sealing layer, the laminate including the photoelectric conversion layer can be protected from the atmospheric environment, particularly from gases such as water and oxygen, and sufficient durability can be obtained. A solar cell with high efficiency and excellent durability can be obtained.

The material of the sealing layer is not particularly limited, and known materials can be used, and may be organic or inorganic.

Normally, the performance of the sealing layer is such that water vapor permeability (environmental conditions: 25 ± 0.5 ° C, relative humidity (90 ± 2)% RH) is about 0.01 g / [m ² · day] or less, oxygen permeability It is preferably a transparent insulating film having a density of about 0.01 cm ³ /[m ² ·day·atm] or less, a resistivity of 1×10 ¹² Ω·cm or more, and gas barrier properties.

In particular, the oxygen permeability is a value of 0.001 cm ³ /[m ² ·day · atm] or less, and the water vapor permeability is a value of about 0.001 g/[m ² ·day] or less. It is preferably composed of a barrier multilayer film. In addition, "water vapor permeability" is a value measured by an infrared sensor method in accordance with JIS (Japanese Industrial Standards)-K7129 (1992), and "oxygen permeability" is JIS-K7126 (1987 It is a value measured by the coulometric method according to the year).

As the material for forming the above-described sealing layer, any material can be used as long as it can suppress the intrusion of gas such as water and oxygen into the organic photoelectric conversion element, which causes deterioration of the photoelectric conversion element. can.

For example, it can be composed of a film made of an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbide, aluminum oxide, aluminum nitride, titanium oxide, zirconium oxide, niobium oxide, and molybdenum oxide. In organic photoelectric conversion elements, the sealing layer is composed of an inorganic material film whose main raw material is a silicon compound such as silicon nitride or silicon oxide, in consideration of gas barrier properties, transparency, and fracturing properties at the time of division. is preferred.

In addition, in order to improve the fragility of the sealing layer, not only the inorganic material coating but also a coating made of a composite material with an organic material, or a hybrid coating in which these coatings are laminated may be configured together. . In this case, the order of lamination of the film made of the inorganic material and the film made of the organic material is arbitrary, but the organic material/inorganic material may be alternately laminated in multiple layers. This makes it possible to obtain a sealing layer having a good barrier function for avoiding damage to the organic photoelectric conversion element due to moisture and oxygen.

Alternatively, the above sealing layer may be used as the first sealing layer, and a second sealing layer may be provided on the upper layer of the sealing layer to further block moisture. It is preferable to form a second encapsulation layer, for example a metal foil, for which optical properties do not have to be considered. The metal layer includes aluminum foil, duralumin foil, titanium foil, copper foil, phosphor bronze foil, SUS304 foil, invar foil, magnesium alloy foil, and mixed foils thereof. Usually these metal foil foils are thin so pinholes and defects can be prevented by making them thicker. Preferably, by forming the metal foil to a thickness of about 5 to 50 μm, it is possible to prepare a metal foil from which pinholes and defects are removed.

For details of solar cells to which the barrier film of the present invention can be applied, for example, JP-A-2014-075194, JP-A-2014-078742, JP-A-2014-131065, JP-A-2014-179225. , JP 2014-229436, JP 2014-232610, JP 2015-012058, JP 2015-128185, JP 2015-141944, JP 2015-149483, Patent The contents described in JP-A-2016-174169, JP-A-2017-118151, etc. can be referred to.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these. In the examples, "parts" or "%" are used, but "mass parts" or "mass%" are indicated unless otherwise specified.

Example 1
<<Preparation of gas barrier film>>
[Preparation of gas barrier film 1]
Exemplified Compound 1 was used as an organic compound that forms a self-filling structure, and Exemplified Compound 1 was dissolved in 2,2,3,3-tetrafluoro-1-propanol, and 0.1 M/L of barrier film forming coating solution 1 was prepared. was prepared.

Then, on a polyethylene naphthalate film (manufactured by Teijin Film Solution Co., Ltd., hereinafter abbreviated as "PET") with a size of 3 cm × 3 cm, wet coating was performed by spin coating under the conditions of 500 rpm and 60 seconds, and hot. Using a plate, it was dried by heating at 100° C. for 30 minutes to prepare a gas barrier film 1 having a barrier film 1 with a thickness of 50 nm as a self-assembled film.

[Preparation of gas barrier films 2 to 6]
Gas barrier films 2 to 6 were produced in the same manner as in the preparation of gas barrier film 1, except that exemplary compound 1, which is an organic compound that forms a self-filling structure, was changed to each compound listed in Table I.

As confirmed by the XRD measurement in Example 4 described later, all of the exemplary compounds used in the production of the gas barrier films 1 to 6 had the highest peak intensity of 500 counts or more in the measured X-ray diffraction spectrum. and the half-value width of the peak was 1.0 degrees or less, confirming that the compound was an organic compound having a self-filling structure.

[Preparation of gas barrier film 7]
A gas barrier film 7 was prepared in the same manner as in the production of the gas barrier film 1, except that a second barrier film was further formed on the barrier film 1 by the following method to form a barrier film laminate.

As the second barrier film, an inorganic gas barrier film made of SiO _x is applied to the entire surface of the barrier film 1 to a thickness of 500 nm using an atmospheric pressure plasma discharge treatment apparatus having the structure described in Japanese Patent Application Laid-Open No. 2004-68143. formed to be

[Production of gas barrier film 8]
In the preparation of the gas barrier film 1, the barrier film 1 was not formed, and the gas barrier film 8 was composed of PET alone.

[Preparation of gas barrier film 9]
A gas barrier film 9 was prepared in the same manner as in the preparation of the gas barrier film 7 except that the barrier film 1 was not formed and the structure was changed to the barrier film 2 having a layer thickness of 500 nm.

[Production of gas barrier film 10]
A gas barrier film 10 was prepared in the same manner as in the preparation of the gas barrier film 9 except that the layer thickness of the barrier film 2 was changed to 2000 nm.

[Production of gas barrier film 11]
A gas barrier film 11 was prepared in the same manner as in the production of the gas barrier film 1, except that the constituent material of the barrier film 1 was changed from the exemplary compound 1 to the following comparative compound 1.

[Production of gas barrier film 12]
A gas barrier film 12 was prepared in the same manner as in the preparation of the gas barrier film 1, except that the constituent material of the barrier film 1 was changed from the exemplary compound 2 to the following comparative compound 2.

〔ガスバリアーフィルム１３の作製〕
上記ガスバリアーフィルム１の作製において、バリアー膜１の構成材料を、下記に記載のポリマー材料に変更した以外は同様にして、ガスバリアーフィルム１３を作製した。
ポリマー材料：信越化学社製ＫＲ－２５１、厚さ５０ｎｍ、硬化条件：波長３６５ｎｍのＵＶを１ｍｉｎ照射。

[Production of gas barrier film 13]
A gas barrier film 13 was prepared in the same manner as in the preparation of the gas barrier film 1, except that the constituent material of the barrier film 1 was changed to the polymer material described below.
Polymer material: KR-251 manufactured by Shin-Etsu Chemical Co., Ltd., thickness 50 nm, curing conditions: UV irradiation with a wavelength of 365 nm for 1 minute.

<<Preparation of organic EL element>>
According to the method described below, organic EL devices 1 to 13 provided with the gas barrier film having the configuration shown in FIG. 3 were produced.

[Preparation of organic element 1]
A glass substrate on which a 100 nm film of ITO (Indium Tin Oxide) was formed as an anode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, UV ozone cleaned, and fixed to a substrate holder of a vacuum deposition apparatus.

Then, HAT-CN (1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile) was deposited to a thickness of 10 nm to form a hole injection transport layer.

α-NPD (4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl) was then evaporated onto the hole injection layer to provide a hole transport layer with a thickness of 40 nm. .

mCP (1,3-bis(N-carbazolyl)benzene) as a host material and Bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic) as a luminescent compound and were co-deposited so as to be 94% by volume and 6% by volume, respectively, to provide a 30 nm-thick light-emitting layer.

After that, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) was evaporated to form an electron transport layer with a thickness of 330 nm.

In addition, 100 nm of silver was vapor-deposited to form a cathode.

Finally, the entire surface including the cathode was coated with polydimethylsiloxane (PDMS), irradiated with UV for 1 minute, and then irradiated with VUV for 1 minute to form a sealing layer.

Next, a thermosetting liquid adhesive (epoxy resin) was formed as a resin layer with a thickness of 25 μm on the surface of the gas barrier film 1 on which the barrier film 1 was formed.

Next, the gas barrier film 1 provided with the resin layer was superimposed on the sealing layer of the organic EL element produced above.

Next, the organic EL element provided with the gas barrier film 1 was placed in a decompression device, and pressed under a reduced pressure condition of 0.1 MPa at 90° C. and held for 5 minutes. Subsequently, the sample was returned to the atmospheric pressure environment and heated at 90° C. for 30 minutes to cure the adhesive.

The above process is performed under atmospheric pressure, in a nitrogen atmosphere with a moisture content of 1 ppm or less, in accordance with JIS B 9920, with a measured cleanliness of class 100, a dew point temperature of −80 ° C. or less, and an oxygen concentration of 0.8 ppm or less. I went at atmospheric pressure. The organic EL element 1 provided with the gas barrier film 1 was produced by the above method.

[Preparation of organic elements 2 to 13]
Organic EL elements 2 to 13 were produced in the same manner as in the production of the organic EL element 1 except that the gas barrier film 1 was changed to the gas barrier films 2 to 13 produced above.

<<Evaluation of gas barrier film: Evaluation of bending resistance>>
Each gas barrier film 1 to 13 used in the production of the above organic EL device was evaluated for bending resistance according to the following method.

Each of the prepared gas barrier films was held for 1000 hours under the conditions of 60° C. and 90% RH while being wound around a cylinder with a diameter of 20 mmφ under the condition that the barrier film was on the outside. After holding for 1000 hours, the appearance of the barrier film of the gas barrier film was visually observed, and cracks were evaluated according to the following criteria. A linear defect having a thickness of 0.5 μm or more and a length of 1000 μm or more was evaluated as a crack.
○: less than 5 cracks in 100 cm ² △: 5 or more cracks in 100 cm ² and less than 50 ×: 50 or more cracks in 100 cm ² <<Evaluation of durability of organic EL element: Dark spot resistance Evaluation of"
Dark spot resistance was evaluated by observing the luminous state of each organic EL device prepared above after being left in an environment of 60° C. and 90% RH for one week.

Specifically, a part of the light emitting portion of the organic EL device was enlarged and photographed with an optical microscope (manufactured by Moritex Co., Ltd. MS-804, lens MP-ZE25-200) with a magnification of 100. Next, the photographed image was cut out into 2 mm squares, and each image was observed for the presence or absence of dark spots. From the observation results, the ratio of the dark spot generation area to the light emitting area was determined, and the dark spot resistance was evaluated according to the following criteria.

A: Dark spot generation area is less than 0.1% B: Dark spot generation area is 0.1% or more and less than 1.0% B: Dark spot generation area is 1.0% % or more and less than 2.5% ×: Dark spot generation area is 2.5% or more and less than 5.0% XX: Dark spot generation area is 5.0% or more Table I shows the results obtained by

表Ｉに記載の結果より明らかなように、本発明のバリアー膜は屈曲耐性に優れ、折り曲げ応力を受けたのちでも、フレキシブル性に優れていることがわかる。

As is clear from the results shown in Table I, the barrier film of the present invention has excellent bending resistance and excellent flexibility even after being subjected to bending stress.

In addition, the gas barrier film of the present invention having a self-assembled film as a barrier film, compared to the gas barrier film 8 having no gas barrier film as a comparative example, under a high temperature and high humidity environment of 60 ° C. and 90% RH. It can be seen that even after storage at room temperature, it is possible to obtain an organic EL element which can block the intrusion of moisture and the like into the main body of the organic EL element and which has excellent durability.

Example 2
Corrosion resistance of the barrier film of the present invention to metal materials was evaluated according to the following method.

<<Preparation of evaluation sample>>
A copper substrate was subjected to electroless palladium plating and displacement gold plating by the EPIG method (electroless palladium immersion gold) to prepare a substrate for evaluation composed of Cu--Pd--Au.

(Preparation of Evaluation Sample 21)
Exemplified Compound 1 was used as an organic compound that forms a self-filling structure on an evaluation substrate, and Exemplified Compound 1 was dissolved in 2,2,3,3-tetrafluoro-1-propanol to form a 0.1 M/L barrier. The film-forming coating liquid 1 was applied under the condition that the film thickness after drying was 50 nm to form a barrier film 21, and an evaluation sample 21 having the configuration shown in FIG. 5 was produced.

In FIG. 5, the evaluation sample (20) is obtained by forming a copper substrate (22) on a substrate (21), coating its surface with electroless Pd plating (23), and then applying substitution Au plating (24). After that, a barrier film (25) was formed on the surface. In the above description, the numbers in parentheses indicate the code numbers shown in FIG.

(Preparation of evaluation samples 22 to 26)
Evaluation samples 22 to 26 were prepared in the same manner as in the preparation of evaluation sample 21, except that exemplary compound 1, which is an organic compound that forms a self-filling structure, was changed to each compound listed in Table II.

As confirmed by the XRD measurement in Example 4 described later, each exemplary compound used in the preparation of the above evaluation samples 21 to 26 has a maximum peak intensity of 500 counts or more in the measured X-ray diffraction spectrum. and the half-value width of the peak was 1.0 degrees or less, confirming that the compound was an organic compound having a self-filling structure.

(Preparation of Evaluation Sample 27)
In the preparation of the evaluation sample 21, instead of the barrier film 21, a self-assembled monolayer (SAM) was formed according to the method described in paragraphs (0033) to (0043) of JP-A-2002-327283. ) was prepared in the same manner as described above, except for forming an evaluation sample 27.

(Preparation of Evaluation Sample 28)
A single substrate for evaluation without forming a barrier film was used as sample 28 for evaluation.

<<Evaluation of corrosion resistance of evaluation samples>>
After leaving each evaluation sample in an environment of 60° C. and 90% RH for one week, the state of deterioration of the copper substrate was observed to evaluate the inhibitory effect of each barrier film on corrosion.

Specifically, FIB-SEM (focused ion beam) was used to obtain a cross-sectional image of the copper substrate to evaluate the degree of corrosion, and the corrosion resistance was evaluated according to the following criteria.

◎: No corrosive substances are observed on the surface of the copper substrate. ○: Almost no corrosive substances are observed on the surface of the copper substrate. Practically no problem x: Obvious occurrence of corroded substances on the surface of the copper substrate, which is practically problematic The results obtained from the above are shown in Table II.

表IIに記載の結果より明らかなように、ＳＡＭ膜で被覆した評価サンプル２７は、銅表面上に通常の銅とは明らかに異なる腐食物が観測された。これに対し、自己充填構造を形成する有機化合物で被覆してバリアー膜を形成した本発明の評価サンプル２１～２６では、分子が規則的に配列することで形成される自己組織化膜が、金属下地（銅基体）に対しても高いバリアー性を有することがわかる。

As is clear from the results shown in Table II, evaluation sample 27 covered with the SAM film had corrosive substances on the copper surface that were clearly different from normal copper. On the other hand, in the evaluation samples 21 to 26 of the present invention, in which the barrier film was formed by coating with an organic compound that forms a self-filling structure, the self-assembled film formed by regularly arranging molecules was formed by metal It can be seen that it also has a high barrier property against the base (copper substrate).

Example 3
The tensile resistance of the barrier film of the present invention was evaluated according to the method described below.

<<Preparation of evaluation sample>>
[Preparation of Evaluation Sample 31]
Example compound 1 is used as an organic compound that forms a self-filling structure on silicone rubber (Sylgard 184 manufactured by Dow Corning), and example compound 1 is dissolved in 2,2,3,3-tetrafluoro-1-propanol. A barrier film 31 was formed by applying a 1 M/L barrier film-forming coating liquid 1 under the condition that the film thickness after drying was 50 nm, thereby preparing a sample 31 for evaluation of tensile resistance.

(Preparation of evaluation samples 32 to 36)
Evaluation samples 32 to 36 were prepared in the same manner as in the preparation of evaluation sample 31, except that exemplary compound 1, which is an organic compound that forms a self-filling structure, was changed to each compound listed in Table III.

<<Evaluation of tensile resistance of evaluation sample>>
Each of the evaluation samples prepared above was stretched for 1 minute at a stretch rate of 150% using a Tensilon universal tensile tester (manufactured by A&D Co., Ltd.) in an environment of 23 ° C. and 55% RH, and then released. Then, after 1 minute, the operation of stretching again for 1 minute under the condition of 150% expansion and contraction was continued for 1 hour, and then the appearance of the evaluation sample was observed with an optical microscope. A defect having a length of 1000 μm or more was evaluated as a crack.

If the number of cracks in an area of 100 cm ² was less than 5, it was judged as “◯”, and if it was 5 or more, it was judged as “×”. The results obtained are shown in Table III.

表IIIに記載の結果より明らかなように、本発明のバリアー膜は引張耐性が非常に優れていることが明らかとなった。

As is clear from the results shown in Table III, it was found that the barrier film of the present invention has excellent tensile resistance.

Example 4
An evaluation sample was prepared according to the following method, and the peak intensity and half-value width of the formed barrier film were measured by XRD measurement.

<<Preparation of evaluation sample>>
[Preparation of Evaluation Sample 41]
Exemplified Compound 1 was used as an organic compound that forms a self-filling structure on a single crystal silicon substrate, and Exemplified Compound 1 was dissolved in 2,2,3,3-tetrafluoro-1-propanol to form a 0.1 M/L barrier. The coating liquid 1 for film formation was applied under the condition that the film thickness after drying was 50 nm, and the barrier film 41 was produced by air drying.

[Preparation of evaluation samples 42 to 46]
Evaluation samples 42 to 46 were prepared in the same manner as in the preparation of evaluation sample 41, except that exemplary compound 1, which is an organic compound that forms a self-filling structure, was changed to each compound listed in Table IV.

[Preparation of Evaluation Sample 47]
An evaluation sample 47 was prepared in the same manner as in the preparation of the evaluation sample 41 above, except that after the barrier film 41 was formed on the single crystal silicon substrate, annealing was performed at 120° C. for 1 hour.

[Preparation of Evaluation Sample 48]
Using a commercially available vacuum deposition apparatus, under a reduced pressure environment of 4 × 10 ^-4 Pa, the single crystal silicon substrate is set to a substrate temperature of 25 ° C., Exemplary compound 1 is heated to about 200 ° C. above the melting point, and vacuum deposition is performed. Then, a barrier film 48 was formed and an evaluation sample 48 was produced. The thickness of the deposited film of Exemplified Compound 1 was 62 nm.

[Preparation of Evaluation Sample 49]
Evaluation sample 49 was prepared in the same manner as preparation of evaluation sample 47 except that comparative compound 1 used in Example 1 was used instead of exemplified compound 1.

[Preparation of evaluation sample 50]
Evaluation sample 50 was prepared in the same manner as in preparation of evaluation sample 47 except that comparative compound 2 used in Example 1 was used instead of exemplified compound 1 .

<<XRD measurement of evaluation sample>>
For each evaluation sample produced above, X-ray diffraction spectrum measurement (XRD measurement) was performed according to the following method.

XRD measurement was performed by the Out-of-Plsane measurement method (2θ/ω method).

As an XRD measurement device, a thin film single crystal analysis X-ray diffraction device "X'Pert ³ MRD XL" (manufactured by Malvern Panalytical) was used, and the intensity of the highest intensity peak and the half-value width of the peak were determined.

When the peak intensity with the highest intensity was 500 counts or more, it was judged as "◯", and when it was less than 500 counts, it was judged as "x". Similarly, when the half-value width of the peak with the highest intensity was 1.0 degrees or less, it was evaluated as "O", and when it exceeded 1.0 degrees, it was evaluated as "X".

Furthermore, when both the peak intensity and the half width are evaluated as "O", it is determined to have the self-filling structure defined in the present invention, and either one or both characteristics are "x". In the case, it was determined that the self-assembled membrane defined in the present invention is not applicable.

The results obtained above are shown in Table IV.

表IVに記載の結果より明らかなように、本発明に係る化合物を用い、湿式塗布法によりバリアー膜を形成する方法が、基材の種類によらずＸＲＤ測定で非常に強度が高く、半値幅の小さなピークが得られることがわかる。これは分子が規則的配列により自己組織化することで密な結晶構造をとることにほかならず、このことから本発明で規定する化合物は、湿式塗布法によりバリアー膜を形成することにより、緻密な構造とすることができることが明らかとなった。

As is clear from the results shown in Table IV, the method of forming a barrier film by a wet coating method using the compound according to the present invention exhibits extremely high strength in the XRD measurement regardless of the type of substrate, and the half-value width It can be seen that a small peak of is obtained. This is nothing other than that the molecules self-organize in a regular arrangement to take a dense crystal structure, and for this reason, the compounds defined in the present invention can form a dense crystal structure by forming a barrier film by a wet coating method. It was found that the structure can be

Example 5
《Application of gas barrier film to solar cells》
As a result of applying each gas barrier film of the present invention produced in Example 1 as the gas barrier film (F) shown in FIG. confirmed that it can be done.

REFERENCE SIGNS LIST 1 organic EL element 2, 25 barrier film 4 first electrode 6 organic functional layer group 7 second electrode 8 first sealing layer 9 second sealing layer 20 evaluation sample 21 substrate 22 copper substrate 23 electroless Pd plating 24 substitution Au Plating 30 inkjet head 31, 39 pump 32 filter 33 pipe branch 34 waste liquid tank 35 controller 36, 37, 38A, 38B tank 50 solar cell 52 first substrate 53 gas barrier film 54 first electrode 55 electron transport layer 56 hole transport Layer 57 Photoelectric conversion unit 58 Second electrode 59 Sealing layer 60 Adhesive layer 61 Aluminum foil 62 PET film 63 Second substrate F Flexible substrate G Glass substrate

Claims (10)

A barrier film against gases or liquids,
consisting mainly of molecules of organic compounds in at least self-filling structures,
A barrier film , wherein the molecule of the organic compound has 3-fold, 4-fold or 6-fold rotational symmetry . A barrier film against gases or liquids,
consisting mainly of molecules of organic compounds in at least self-filling structures,
A barrier film composed of molecules of the organic compound is prepared on a silicon wafer, and in an X-ray diffraction spectrum obtained by X-ray diffraction measurement of the barrier film, the intensity of the highest intensity peak is 500 counts or more, and the peak is A barrier film having a half-value width of 1.0 degree or less. 3. The barrier film according to claim 1, wherein the organic compound has a molecular weight of 1000 or less. 4. The barrier film according to any one of claims 1 to 3 , wherein the barrier film is a coating film. 5. A barrier film manufacturing method for manufacturing the barrier film according to any one of claims 1 to 4 , wherein the barrier film is formed by a wet coating method. Method. 6. The method for producing a barrier film according to claim 5 , wherein the wet coating method is an inkjet printing method, a spin coating method or a dispenser method. A barrier film laminate having barrier properties against gases or liquids,
A barrier film laminate comprising at least the barrier film according to any one of claims 1 to 4 and a different barrier film, wherein the different barrier film is made of an inorganic material. An electronic device comprising the barrier film according to any one of claims 1 to 4 . 9. The electronic device according to claim 8 , wherein said electronic device is an electroluminescence element. 9. The electronic device according to claim 8 , wherein said electronic device is a solar cell, a semiconductor, an LED or a secondary battery.

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