JP2022182017A - Curable resin composition and organic EL element - Google Patents

Abstract

To provide a curable resin composition in which progress of curing reaction is hardly inhibited.SOLUTION: A curable resin composition contains a cationic polymerizable resin, an acid generator and metal alkoxide, wherein the acid generator is quaternary ammonium salt.SELECTED DRAWING: None

Description

The present invention relates to a curable resin composition and an organic EL device.

In an organic EL device, a sealant such as a filler is sometimes provided to fill an airtight space around a light-emitting organic layer (for example, Patent Document 1).

JP 2017-059413 A

A curable resin composition as a sealant for an organic EL device contains a water-capturing component (for example, a metal alkoxide), so that the curable resin has a water-capturing function for suppressing the influence of moisture on the organic EL device. It is believed that it can be applied to the composition. However, when the curable resin composition contains a cationic polymerizable resin and an acid generator, progress of the curing reaction may be inhibited due to the influence of the water trapping component. When the progress of the curing reaction is inhibited, it tends to be difficult to fix the curable resin composition in an appropriate position.

Accordingly, the main object of the present invention is to provide a curable resin composition in which the progress of the curing reaction is less likely to be inhibited.

Metal alkoxides having various central metals are expected to function as water trapping components. However, according to the studies of the present inventors, it was found that the acid generator was deactivated by the metal alkoxide, which is a water trapping component, and that this was the cause of the inhibition of the progress of the curing reaction. Accordingly, the present inventors investigated the type of acid generator and found that the progress of the curing reaction was inhibited when a quaternary ammonium salt was applied as an acid generator to a curable resin composition containing a metal alkoxide. I found it difficult and came to complete the present invention.

One aspect of the present invention relates to a curable resin composition. The curable resin composition contains a cationic polymerizable resin, an acid generator, and a metal alkoxide. Acid generators are quaternary ammonium salts. Such a curable resin composition tends to be less likely to hinder the progress of the curing reaction. The reason why such an effect is produced is not necessarily clear, but the inventors think as follows. Acid generators are usually salts composed of cations and anions. It is speculated that acid generators containing quaternary ammonium cations are more stable as salts composed of cations and anions than acid generators containing cations such as sulfonium and iodonium, from the viewpoint of element properties. Therefore, the quaternary ammonium salt as an acid generator is less likely to be deactivated even if a metal alkoxide is present in the system, and the progress of the curing reaction is inhibited in a curable resin composition containing such an acid generator. It is considered difficult.

The cationically polymerizable resin may be an epoxy resin.

The metal alkoxide may contain an alkoxy group having a cationically polymerizable group. The metal alkoxide may contain a group derived from a β-diketone compound or a group derived from a β-ketoester compound.

The central metal of the metal alkoxide may be a Group 4 element of the periodic table, a Group 13 element of the periodic table, or a Group 14 element of the periodic table.

Another aspect of the present invention relates to an organic EL device. The organic EL element includes an element substrate, a sealing substrate facing the element substrate, a pair of electrodes facing the element substrate, and an organic layer provided therebetween. and a sealing layer provided between the element substrate and the sealing substrate for sealing the light emitting portion. The sealing layer contains a cured product of the above curable resin composition. Such an organic EL device can be produced efficiently because the progress of the curing reaction of the curable resin composition is hardly hindered, and has a good light emission life due to the water trapping function of the sealing layer. can be expected.

In one aspect of the organic EL element, the sealing layer fills the space around the light-emitting portion between the element substrate and the sealing substrate while being in contact with the element substrate and the sealing substrate. Another aspect of the organic EL element further includes a sealing sealant for sealing the outer peripheral portions of the element substrate and the sealing substrate, and the sealing layer forms an airtight space around the light emitting portion inside the sealing sealant. filling at least a portion of the In another aspect of the organic EL element, the sealing layer has a laminate structure including a cured film containing a cured product of the curable resin composition and an inorganic film.

ADVANTAGE OF THE INVENTION According to this invention, the curable resin composition which progress of a curing reaction is hard to be inhibited is provided. Further, according to the present invention, an organic EL device using such a curable resin composition is provided.

FIG. 1 is a schematic cross-sectional view showing one embodiment of an organic EL element. FIG. 2 is a schematic cross-sectional view showing another embodiment of the organic EL device. FIG. 3 is a schematic cross-sectional view showing another embodiment of the organic EL device. FIG. 4 is a schematic cross-sectional view showing another embodiment of the organic EL element.

Several embodiments of the invention are described in detail below. However, the present invention is not limited to the following embodiments.

As used herein, "(meth)acrylate" means at least one of acrylate and methacrylate corresponding thereto. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid".

[Curable resin composition]
A curable resin composition of one embodiment contains a cationic polymerizable resin, an acid generator, and a metal alkoxide. The curable resin composition may be a thermosetting resin composition that is cured by heat.

<Cationically polymerizable resin>
The cationically polymerizable resin is, for example, a curable resin that forms a cured product (crosslinked polymer) by reacting with the action of an acid or the like, and contains a cationically polymerizable group (for example, an epoxy group, an oxetanyl group, a vinyl ether group, etc.). It can be a curable resin having The cationically polymerizable resin may be, for example, an epoxy resin, an oxetane resin, or the like, from the viewpoint of enhancing the curability of the cured product, adhesion to the substrate, and flexibility.

Epoxy resins may be compounds having one or more epoxy groups. Compounds having one or more epoxy groups include, for example, propylene oxide, butylene oxide, styrene oxide, glycidyl phenyl ether, ethylene glycol diglycidyl ether, alicyclic epoxy resins (e.g., 3,4-epoxycyclohexylmethyl-3 ,4-epoxycyclohexanecarboxylate), bisphenol A type epoxy resin (e.g., 2,2-bis(4-glycidyloxyphenyl)propane), bisphenol F type epoxy resin (e.g., bis[4-(glycidyloxy)phenyl] methane), epoxy-modified silicone, and the like.

Oxetane resins may be compounds having one or more oxetanyl groups. Examples of compounds having one or more oxetanyl groups include oxetane alcohol and 3,3'-oxybis(methylene)bis(3-ethyloxetane).

The content of the cationic polymerizable resin may be, for example, 5 to 98% by mass, 50 to 95% by mass, or 80 to 92% by mass based on the total amount of the curable resin composition.

<Acid Generator>
The acid generator is, for example, a chemical species that initiates polymerization by generating an acid or the like by light or heat, and is usually a salt composed of a cation and an anion. The acid generator may be, for example, a thermal acid generator that generates acid or the like by heat.

Acid generators are quaternary ammonium salts having quaternary ammonium cations as cations. A quaternary ammonium salt may be, for example, a salt having a cation represented by the following formula (1).

In formula (1), R ¹ , R ² , R ³ , and R ⁴ each independently have an optionally substituted alkyl group having 1 to 18 carbon atoms and a substituent is an aralkyl group having 7 to 20 carbon atoms, which may be substituted, or an aryl group having 6 to 18 carbon atoms, which may have a substituent.

Examples of substituents include halogen atoms, cycloalkyl groups (preferably cycloalkyl groups having 3 to 8 carbon atoms), alkoxy groups (preferably alkoxy groups having 1 to 6 carbon atoms), cycloalkyloxy groups (preferably is a cycloalkyloxy group having 3 to 8 carbon atoms), an aryloxy group (preferably an aryloxy group having 6 to 14 carbon atoms), an aralkyloxy group (preferably an aralkyloxy group having 7 to 16 carbon atoms), etc. is mentioned.

A salt having a cation represented by formula (1) may be, for example, an anilinium salt. That is, in formula (I), at least one of R ¹ , R ² , R ³ and R ⁴ may be an optionally substituted aryl group having 6 to 18 carbon atoms. Anilinium salts include N,N-dialkylanilinium salts such as N,N-dimethylanilinium salts and N,N-diethylanilinium salts.

Anions of quaternary ammonium salts include, for example, BF ₄ ⁻ , BR ₄ ⁻ (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ and the like. The anion of the quaternary ammonium salt may be an anion containing boron as a constituent element, such as tetrakis(pentafluorophenyl)borate.

A commercially available quaternary ammonium salt can be used as an acid generator. Examples of commercial products of anilinium salts having an anion containing boron as a constituent element include K-PURE CXC1821 (trade name, manufactured by King Industries).

The content of the acid generator may be, for example, 0.1 to 10% by mass, 0.3 to 5% by mass, or 0.5 to 3% by mass based on the total amount of the curable resin composition.

<Metal alkoxide>
A metal alkoxide means a metal compound with at least one alkoxy group. Metal alkoxides having various central metals are expected to function as water trapping components.

The central metal of the metal alkoxide may be a Group 4 element of the periodic table, a Group 13 element of the periodic table, or a Group 14 element of the periodic table from the viewpoint of its function as a water trapping component. The Group 4 element of the periodic table may be a titanium atom or a zirconium atom. The Group 13 element of the periodic table may be a boron atom or an aluminum atom. The Group 14 element of the periodic table may be a silicon atom or a germanium atom. Among these, the central metal of the metal alkoxide may be a titanium atom or a zirconium atom. When the central metal of the metal alkoxide is a titanium atom or a zirconium atom, the progress of the curing reaction tends to be more difficult to be inhibited.

Examples of the alkyl group in the alkoxy group of the metal alkoxide include linear, branched or cyclic alkyl groups. Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group and sec-pentyl. group, neopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, nonyl group, decanyl group, dodecanyl group, tetradecanyl group and hexadecanyl group. The number of carbon atoms in the alkyl group may be 1-28 or 1-8.

Some or all of the alkoxy groups in the metal alkoxide may be substituted with aryloxy groups. Examples of the aryl group in the aryloxy group include a phenyl group. The aryl group may have from 6 to 18 carbon atoms.

The metal alkoxide may contain an alkoxy group having a cationically polymerizable group. When the metal alkoxide contains an alkoxy group having a cationically polymerizable group, the cationically polymerizable group of the metal alkoxide is polymerized in the polymerization of the cationically polymerizable resin. Improvement can be expected. Moreover, the alkoxy group of the metal alkoxide may be eliminated as an alcohol after water is captured. When the desorbed alcohol is released as outgas, it causes deterioration of the organic EL element. When the metal alkoxide contains an alkoxy group having a cationically polymerizable group, the released alcohol is taken in during the polymerization of the cationically polymerizable resin, so that outgassing can be suppressed, and as a result, the organic EL element can be produced. Deterioration can be prevented.

Examples of cationic polymerizable groups include epoxy groups, oxetanyl groups, and vinyl ether groups. Among these, the cationically polymerizable group may be an epoxy group.

Examples of the alkoxy group having a cationic polymerizable group include an alkyl group represented by the following formula (2) (a group derived by removing one hydrogen atom from the hydroxyl group of glycerol diglycidyl ether). Note that * means a bond.

The metal alkoxide may contain a group derived from a β-diketone compound or a group derived from a β-ketoester compound. β-diketone compounds and β-ketoester compounds exhibit keto-enol tautomerism. For example, the β-diketone compound can take the keto form and enol form shown below. The group derived from the β-diketone compound may be a group derived by removing one hydrogen atom from the hydroxyl group of the enol form of the β-diketone compound. The group derived from the β-ketoester compound may be a group derived by removing one hydrogen atom from the hydroxyl group of the enol form of the β-ketoester compound. These groups can be chelated by coordinating the carbonyl group of the β-diketone compound or the carbonyl group of the β-ketoester compound to the central metal. By chelating these groups, it becomes possible to suppress the reactivity of the metal alkoxide (hydrolysis reaction when acting as a water trapping component, reaction with the cationically polymerizable resin, etc.). By suppressing the hydrolysis reaction, it is possible to suppress the deposition of oxides or hydroxides, and it is expected that the desiccant will be easy to handle even at a low dew point when actually used. In addition, by suppressing the reaction with the cationically polymerizable resin, thickening or gelling of the resin can be suppressed, and it is expected that the amount of the curable resin composition to be applied can be easily controlled to be constant. Furthermore, compared to general alkoxy groups (e.g., ethoxy groups, propoxy groups), outgassing (e.g., ethanol derived from ethoxy groups, propanol from propoxy groups) is more stable when chelated. It can also be expected that the occurrence can be suppressed.

In the formula, R ^A represents an alkyl group having 1 to 28 carbon atoms such as methyl, ethyl or heptyl, or an allyl group. Some or all of the hydrogen atoms in the alkyl group may be substituted with fluorine atoms.

Examples of β-diketone compounds include acetylacetone, alkyl (ethyl, heptyl, etc.) acetylacetone, allylacetylacetone and the like. Some or all of the hydrogen atoms in the alkyl group of the β-diketone compound may be substituted with fluorine atoms. β-diketone compounds substituted with fluorine atoms include, for example, hexafluoroacetylacetone and the like. Examples of β-ketoester compounds include alkyl acetoacetate (ethyl, heptyl, etc.), dialkyl malonate (dimethyl, diethyl, etc.), and the like. Some or all of the hydrogen atoms of the alkyl group of the β-ketoester compound may be substituted with fluorine atoms.

A metal alkoxide may be, for example, a compound represented by the following general formula (3).

M (OR) _m (R') _n (3)

In formula (3), M represents a Group 4 element of the periodic table, a Group 13 element of the periodic table, or a Group 14 element of the periodic table. m represents an integer of 1 to 4, n represents an integer of 0 to 2, and m+n represents 3 or 4. R represents an alkyl group optionally substituted with a group containing a cationic polymerizable group. When there are multiple R's, the R's may be the same or different. R' represents a group derived from a β-diketone compound or a group derived from a β-ketoester compound. When there are multiple R's, the R's may be the same or different.

The Group 4 element of the periodic table may be a titanium atom or a zirconium atom. The Group 13 element of the periodic table may be a boron atom or an aluminum atom. The Group 14 element of the periodic table may be a silicon atom or a germanium atom. M may be a titanium atom or a zirconium atom since the progress of the curing reaction is much less likely to be inhibited.

m+n is 3 when M is a Group 13 element of the periodic table. When m+n is 3, m may be an integer from 1 to 3 and n may be an integer from 0 to 2. m+n is 4 when M is a Group 4 element of the periodic table or a Group 14 element of the periodic table. When m+n is 4, m may be an integer from 2 to 4 and n may be an integer from 0 to 2.

In formula (3), R represents an alkyl group optionally substituted with a group containing a cationic polymerizable group. The alkyl group optionally substituted with a group containing a cationically polymerizable group means an unsubstituted alkyl group and an alkyl group substituted with a group containing a cationically polymerizable group. An alkyl group substituted with a group containing a cationically polymerizable group means an alkyl group in which one or more arbitrary hydrogen atoms of an unsubstituted alkyl group are substituted with a group containing a cationically polymerizable group.

Examples of the unsubstituted alkyl group include those similar to the alkyl group in the alkoxy group of the metal alkoxide described above. The number of carbon atoms in the unsubstituted alkyl group may be 1-28 or 1-8.

A group containing a cationic polymerizable group is, for example, a group containing a cationic polymerizable group such as an epoxy group, an oxetanyl group, or a vinyl ether group. Groups containing a cationic polymerizable group include, for example, an alcohol residue having an epoxy ring (eg, a glycidyl ether group), an alcohol residue having an oxetane ring, and the like. Among these, the group containing a cationic polymerizable group may be an alcohol residue having an epoxy ring or a glycidyl ether group.

Examples of alkyl groups substituted with groups containing cationic polymerizable groups include alkyl groups represented by the following formula (4). Note that * means a bond.

In formula (4), R' represents a group derived from a β-diketone compound or a group derived from a β-ketoester compound. The group derived from the β-diketone compound may be a group derived by removing one hydrogen atom from the hydroxyl group of the enol form of the β-diketone compound. The group derived from the β-ketoester compound may be a group derived by removing one hydrogen atom from the hydroxyl group of the enol form of the β-ketoester compound. A group derived from a β-diketone compound or a group derived from a β-ketoester compound may form a chelate by forming a complex with M in the carbonyl group in the β-diketone compound or β-ketoester compound. does not have to form That is, the group derived from the β-diketone compound or the group derived from the β-ketoester compound may act as a chelate ligand or may act as a monodentate ligand. . When R' is a group derived from a β-diketone compound, the case where it acts as a chelating ligand or the case where it acts as a monodentate ligand is as shown below.

In the above formula, M and ^RA have the same definitions as above.

A compound represented by the general formula (3) having an alkyl group and/or a group derived from a β-diketone compound or a group derived from a β-ketoester compound substituted with a group containing a cationically polymerizable group is, for example, periodic A compound having a central atom of any of Group 4 elements of the periodic table, Group 13 elements of the periodic table, or Group 14 elements of the periodic table, and an alcohol corresponding to an alkyl group substituted with a group containing a cationically polymerizable group and / Alternatively, it can be obtained by reacting a β-diketone compound or a β-ketoester compound. The alcohol and/or the β-diketone compound or the β-ketoester compound corresponding to the alkyl group substituted with a group containing a cationically polymerizable group may be added at the same time and reacted. The other may be added and reacted.

A compound having a central atom of an element of Group 4 of the periodic table, an element of Group 13 of the periodic table, or an element of Group 14 of the periodic table has an alkoxy group corresponding to the above unsubstituted alkyl group bonded to the central atom. It may be a compound having A compound in which an alkoxy group corresponding to an unsubstituted alkyl group is bonded to the central atom can also be used as a compound represented by general formula (3). As for the compound in which an alkoxy group corresponding to an unsubstituted alkyl group is bonded to the central atom, a commercially available product can be used as it is.

As the compound represented by the general formula (3) having a group derived from a β-diketone compound or a group derived from a β-ketoester compound, a commercially available product can be used as it is. A group derived from an alkyl group substituted with a group containing a cationically polymerizable group and a β-diketone compound or A compound represented by general formula (3) having a group derived from a β-ketoester compound can be obtained.

In the compound represented by the general formula (3), the number of introduced alkyl groups substituted with a group containing a cationically polymerizable group and the number of introduced groups derived from a β-diketone compound or a group derived from a β-ketoester compound Adjustments correspond to alkyl groups substituted with groups containing cationically polymerizable groups for compounds having central atoms of any of the elements of Group 4 of the Periodic Table, Group 13 of the Periodic Table, or Group 14 of the Periodic Table. It can be carried out by adjusting the reaction ratio of the alcohol and the β-diketone compound or β-ketoester compound.

Reaction conditions can be appropriately selected according to the raw materials used. The reaction conditions can be adjusted, for example, in the absence or presence of a solvent, the reaction temperature of 0° C. to 150° C., and the reaction time of 0.5 to 48 hours. After the reaction is completed, volatile components may be distilled off under reduced pressure.

The content of the metal alkoxide may be, for example, 1 to 99% by mass, 5 to 50% by mass, or 8 to 30% by mass based on the total amount of the curable resin composition.

The curable resin composition may mainly consist of a cationically polymerizable resin, an acid generator, and a metal alkoxide. The total content of the cationic polymerizable resin, the acid generator, and the metal alkoxide is, for example, 30 to 99.9% by mass, 50 to 99.9% by mass, or 70%, based on the total amount of the curable resin composition. ~99.9% by weight.

The curable resin composition may further contain components other than the cationic polymerizable resin, acid generator, and metal alkoxide. Other components include, for example, curing reaction retarders, radically polymerizable resins (compounds having radically polymerizable groups), radical polymerization initiators, and the like.

The curable resin composition may further contain a curing reaction retarder from the viewpoint of ensuring the pot life. The curing reaction retarder is not particularly limited, but may be, for example, a polyol compound. Examples of polyol compounds include crown ethers.

The curable resin composition may further contain a radically polymerizable resin from the viewpoint of curability or substrate adhesion. Examples of the radically polymerizable group in the radically polymerizable resin include a (meth)acryloyl group. The radically polymerizable resin may be an acrylic resin having a (meth)acryloyl group, more specifically a compound having one or more (meth)acryloyl groups. Compounds having one or more (meth)acryloyl groups include, for example, (meth)acrylic acid, octyl (meth)acrylate, stearyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 2-(o-phenyl phenol)ethyl (meth)acrylate, hydroxyethyl (meth)acrylate, 1,4-butanediol di(meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (Meth)acrylate and the like.

When the curable resin composition contains a radically polymerizable resin, it may further contain a radical polymerization initiator. Examples of radical polymerization initiators include, but are not limited to, azo compounds, organic peroxides, benzoin ketals, α-hydroxyketones, α-aminoketones, oxime esters, phosphine oxides, triarylimidazole dimers, benzophenone compounds, quinone compounds, benzoin ethers, benzoin compounds, benzyl compounds, acridine compounds, N-phenylglycine, coumarin and the like.

The curable resin composition may be a coatable ink composition. The curable resin composition can be applied to, for example, an inkjet coating method, a dispensing coating method, an ODF (One Drop Fill) method, a screen printing method, a spray method, a hot melt method, and the like. Since the curable resin composition is suitable for forming a coating film, it may be an ink composition for inkjet coating. When applied to an ink-jet coating method, the viscosity of the curable resin composition at 25° C. may be 0.01 to 30 mPa·s.

The curable resin composition can be cured (formed into a cured product) by heating. The heating conditions can be adjusted, for example, within the range of a heating temperature of 40° C. to 150° C. and a reaction time of 0.1 to 5 hours.

The curable resin composition can be used as an organic EL sealant for sealing the periphery of the light-emitting portion of the organic EL element. The organic EL element sealing agent may be, for example, a filling agent that fills an airtight space around the light emitting portion.

[Organic EL element]
FIG. 1 is a schematic cross-sectional view showing one embodiment of an organic EL element. The organic EL element 1A shown in FIG. and a cathode 6) and an organic layer 4 provided therebetween; a light-emitting portion 10 which is a laminate; A sealing layer 7 for sealing the light-emitting portion 10 inside the sealing agent 8 is provided. The sealing layer 7 contains a cured product of the curable resin composition of the above embodiment. An airtight space is formed around the light emitting section 10 between the element substrate 2 and the sealing substrate 3 by sealing the outer peripheral portions of the element substrate 2 and the sealing substrate 3 with the sealing agent 8 .

The sealing layer 7 fills the airtight space around the light emitting section 10 while being in contact with the element substrate 2 and the sealing substrate 3 inside the sealing sealant 8 . That is, the organic EL element 1A is an organic EL element having a so-called filling and sealing structure, and the sealing layer 7 functions as a filler. The light emitting part 10 is embedded in the sealing layer 7 . However, the airtight space may not be completely filled with the sealing layer 7 and a gap may remain. The proportion of the sealing layer in the airtight space may be, for example, 50-100% by volume, 60-100% by volume, 70-100% by volume, 80-100% by volume, or 90-100% by volume.

Elements other than the sealing layer 7 in the organic EL element 1A can be those commonly used in the technical field, and an example thereof will be described below.

The element substrate 2 is made of a rectangular glass substrate having insulating and translucent properties. An anode 5 (electrode) is formed on the element substrate 2 by ITO (Indium Tin Oxide), which is a transparent conductive material. The anode 5 is formed by, for example, patterning an ITO film formed on the element substrate 2 by a PVD (Physical Vapor Deposition) method such as a vacuum deposition method or a sputtering method into a predetermined pattern shape by etching using a photoresist method. be done. A part of the anode 5 as an electrode is pulled out to the end of the element substrate 2 and connected to a driving circuit (not shown).

An organic layer 4, which is a thin film containing an organic light-emitting material, is laminated on the upper surface of the anode 5 by, for example, a PVD method such as a vacuum deposition method or a resistance heating method. The organic layer 4 may be formed from a single layer, or may be formed from a plurality of layers having different functions. The organic layer 4 in this embodiment has a four-layer structure in which a hole injection layer 4a, a hole transport layer 4b, a light emitting layer 4c, and an electron transport layer 4d are laminated in this order from the anode 5 side. The hole injection layer 4a is made of, for example, copper phthalocyanine (CuPc) with a thickness of several tens of nanometers. The hole transport layer 4b is made of, for example, bis[N-(1-naphthyl)-N-phenyl]benzidine (α-NPD) with a thickness of several tens of nm. The light-emitting layer 4c is made of, for example, tris(8-quinolinolato)aluminum (Alq ₃ ) with a thickness of several tens of nm. The electron transport layer 4d is made of, for example, lithium fluoride (LiF) with a thickness of several nanometers.

On the upper surface of the organic layer 4 (electron transport layer 4d), a cathode 6 (electrode), which is a metal thin film formed by a PVD method such as a vacuum deposition method, is laminated. The material of the metal thin film may be, for example, a single metal with a small work function such as Al, Li, Mg or In, or an alloy with a small work function such as Al--Li or Mg--Ag. The cathode 6 has a thickness of, for example, several tens of nm to several hundred nm, or 50 nm to 200 nm. A part of the cathode 6 is pulled out to the end of the element substrate 2 and connected to a drive circuit (not shown).

The sealing substrate 3 is arranged to face the element substrate 2 with the organic layer 4 interposed therebetween. The peripheral portions of the element substrate 2 and the sealing substrate 3 are sealed with a sealing agent 8 . As the sealing agent, for example, an ultraviolet curable resin can be used.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the organic EL device. The organic EL element 1B shown in FIG. A sealing sealant 8 for sealing the outer peripheral portion of the substrate 3, a desiccant layer 9 provided on the inner surface of the sealing sealant 8, and a periphery of the light emitting portion 10 filled inside the desiccant layer 9. It is composed of a sealing layer 7 that Also in the organic EL element 1B, the light-emitting portion 10 is embedded in the sealing layer 7. As shown in FIG. An airtight space between the element substrate 2 and the sealing substrate 3 is filled with the sealing layer 7 and the desiccant layer 9 . The desiccant layer 9 may be, for example, a layer containing oxide particles containing an alkaline earth oxide such as calcium oxide, and a binder.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the organic EL device. The organic EL element 1C shown in FIG. It is composed of a sealing layer 7 that fills the space around the light emitting part 10 between the element substrate 2 and the sealing substrate 3 while being in contact with the substrate 3 . In the case of the organic EL element 1C of FIG. 3, a member such as a sealing sealant that forms an airtight space around the light-emitting portion is not provided, but the light-emitting portion 10 is provided with a sealing layer having water trapping ability. By being embedded in 7, it is possible to have a good emission lifetime.

FIG. 4 is a schematic cross-sectional view showing another embodiment of the organic EL element. An organic EL element 1D shown in FIG. It is composed of a sealing sealant 8 that seals the outer periphery of the substrate 3 and a sealing layer 7 that covers the light emitting portion 10 inside the sealing sealant 8 . In the organic EL element 1D as well, the light emitting section 10 is embedded in the sealing layer 7. As shown in FIG.

The sealing layer 7 constituting the organic EL element 1D has a laminated structure including one cured film 21 containing a cured product of a curable resin composition and two inorganic films 22 . The inorganic film 22, the cured film 21, and the inorganic film 22 are laminated in this order from the light emitting section 10 side. That is, the sealing layer 7 has two inorganic films 22 as outermost layers and a cured film 21 arranged inside them. The number of cured films and inorganic films constituting the sealing layer 7 is not limited, and a plurality of cured films and inorganic films may be alternately laminated. In the case of FIG. 4, the sealing layer 7 covers the light-emitting portion 10 and the surface of the element substrate 2, but the entire surface of the element substrate 2 inside the sealing agent 8 may not be covered. The thickness of the cured film 21 may be, for example, 0.1 to 30 μm.

The inorganic film 22 may be, for example, a film containing a silicon compound selected from silicon nitride (SiN), silicon oxide (SiO), silicon oxide containing nitrogen (SiON), and the like. The inorganic film 22 can be formed, for example, by chemical vapor deposition (CVD). The thickness of the inorganic film 22 may be, for example, 0.1-3 μm.

The organic EL element can be manufactured by a method including applying a curable resin composition to the element substrate 2 or the sealing substrate 3, for example. As in the organic EL element 1D of FIG. 4, a sealing layer having a laminated structure including a cured film and an inorganic film can be produced, for example, by a method including applying a curable resin composition to an inorganic film. .

In the method for manufacturing an organic EL device according to one embodiment, a laminate is prepared in which a light-emitting portion having an organic layer 4 and the like is formed on a device substrate 2 . In this case, the sealing layer 7 is formed by coating the curable resin composition of the above embodiment on the separately prepared sealing substrate 3 by a method such as a dispenser. After that, a sealing agent 8 is applied by a dispenser so as to surround the sealing layer 7 applied on the sealing substrate 3 . These operations may be performed in a nitrogen-purged glove box with a dew point of -76°C or lower.

Next, the element substrate 2 on which the light-emitting portion is mounted and the sealing substrate 3 are bonded together while sandwiching the sealing layer 7 and the sealing sealant 8 therebetween. The organic EL device 1A is obtained by curing the curable resin composition and/or the sealing sealant on the obtained structure by ultraviolet irradiation and/or heating, if necessary. The organic EL device 1B can also be produced in the same manner except that the desiccant layer is formed using the desiccant composition. The organic EL element 1C can be manufactured by the same method except that the sealing agent is not formed. The organic EL element 1D can be manufactured by a method including sequentially forming an inorganic film and a cured film on the light emitting part.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[Synthesis of titanium alkoxide]
(Production example 1)
In a flask, 10 parts by mass of glycerol diglycidyl ether (2 mol equivalents) was added to 10 parts by mass of titanium diisopropoxybis(ethylacetoacetate) (Orgatics TC-750 (trade name), Matsumoto Fine Chemical Co., Ltd.). , and refluxed at 120° C. for 1 hour. Thereafter, volatile components such as isopropanol generated by the reaction were removed under reduced pressure of 300 Pa at 50° C. for 1 hour, and further removed under reduced pressure of 300 Pa at 120° C. for 1 hour. Alkoxide was obtained. The titanium alkoxide of Production Example 1 is obtained by reacting 2 mol equivalents of glycerol diglycidyl ether with ORGATICS TC-750. It is presumed to be a titanium alkoxide in which R is an alkyl group represented by formula (4) and R' is a group derived from ethyl acetoacetate.

[Preparation of curable resin composition]
(Example 1-1)
100 parts by mass of bisphenol A type epoxy resin (YL983U (trade name), Mitsubishi Chemical Corporation), 1 part by mass of a quaternary ammonium salt acid generator (cation: quaternary ammonium (anilinium), anion: B ( _C6 F ₅ ) ₄ ⁻ , K-PURE CXC1821 (trade name), King Industries), and 10 parts by mass of the titanium alkoxide of Production Example 1 were mixed in a glass vessel to cure the liquid Example 1-1. A flexible resin composition was obtained.

(Comparative Example 1-1)
A liquid curable resin composition of Comparative Example 1-1 was obtained in the same manner as in Example 1-1, except that the quaternary ammonium salt acid generator was not used.

(Comparative Example 1-2)
A quaternary ammonium salt acid generator was replaced with a sulfonium salt acid generator (cation: sulfonium, anion: B(C ₆ F ₅ ) ₄ ⁻ , San-Aid SI-B2A (trade name), Sanshin Chemical Industry Co., Ltd.)). A liquid curable resin composition of Comparative Example 1-2 was obtained in the same manner as in Example 1-1, except that the

(Comparative Example 1-3)
Except for changing the quaternary ammonium salt acid generator to a sulfonium salt acid generator (cation: sulfonium, anion: PF ₆ ⁻ , San-Aid SI-300 (trade name), Sanshin Chemical Industry Co., Ltd.)) A liquid curable resin composition of Comparative Example 1-3 was obtained in the same manner as in Example 1-1.

(Comparative Example 1-4)
Except for changing the quaternary ammonium salt acid generator to a sulfonium salt acid generator (cation: sulfonium, anion: SbF ₆ ⁻ , San-Aid SI-60 (trade name), Sanshin Chemical Industry Co., Ltd.)) A liquid curable resin composition of Comparative Example 1-4 was obtained in the same manner as in Example 1-1.

(Reference example 1-1)
A liquid curable resin composition of Reference Example 1-1 was obtained in the same manner as in Example 1-1, except that the titanium alkoxide of Production Example 1 was not used.

(Reference example 1-2)
A liquid curable resin composition of Reference Example 1-2 was obtained in the same manner as in Comparative Example 1-1, except that the titanium alkoxide of Production Example 1 was not used.

(Reference example 1-3)
A liquid curable resin composition of Reference Example 1-3 was obtained in the same manner as in Comparative Example 1-2, except that the titanium alkoxide of Production Example 1 was not used.

(Reference example 1-4)
A liquid curable resin composition of Reference Example 1-4 was obtained in the same manner as in Comparative Example 1-3, except that the titanium alkoxide of Production Example 1 was not used.

(Example 2-1)
100 parts by mass of bisphenol A epoxy resin (YL983U (trade name), Mitsubishi Chemical Corporation), 1 part by mass of a quaternary ammonium salt acid generator (cation: quaternary ammonium (anilinium), anion: B ( _C6 F ₅ ) ₄ ⁻ , K-PURE CXC1821 (trade name), King Industries), and 10 parts by mass of zirconium tetrapropoxide were mixed in a glass container to prepare the liquid curable resin of Example 2-1. A composition was obtained.

(Example 2-1)
100 parts by mass of bisphenol A type epoxy resin (YL983U (trade name), Mitsubishi Chemical Corporation), 1 part by mass of a quaternary ammonium salt acid generator (cation: quaternary ammonium (anilinium), anion: B ( _C6 F ₅ ) ₄ ⁻ , K-PURE CXC1821 (trade name), King Industries), and 10 parts by mass of zirconium alkoxide (zirconium tetrapropoxide) were mixed in a glass container to form liquid Example 2-1. A curable resin composition was obtained.

(Comparative Example 2-1)
A liquid curable resin composition of Comparative Example 2-1 was obtained in the same manner as in Example 2-1, except that the quaternary ammonium salt acid generator was not used.

(Comparative Example 2-2)
A quaternary ammonium salt acid generator was replaced with a sulfonium salt acid generator (cation: sulfonium, anion: B(C ₆ F ₅ ) ₄ ⁻ , San-Aid SI-B2A (trade name), Sanshin Chemical Industry Co., Ltd.)). A liquid curable resin composition of Comparative Example 2-2 was obtained in the same manner as in Example 2-1, except that the

[Curability evaluation]
0.2 g of each curable resin composition was added to a screw bottle and heated at 100° C. for 1 hour. After heating, it was confirmed whether or not the curable resin composition was cured. If it was cured, it was evaluated as "cured", and if it was not cured, it was evaluated as "uncured". The results are shown in Tables 1 and 2.

As shown in Table 1, all of the curable resin compositions of Reference Examples 1-1 to 1-4 containing an epoxy resin and an acid generator but no metal alkoxide were cured after heating. On the other hand, in the curable resin composition containing an epoxy resin, an acid generator, and a metal alkoxide, the curable resin composition of Example 1-1, in which the acid generator is a quaternary ammonium salt, after heating Although cured, the curable resin compositions of Comparative Examples 1-2 to 1-4, in which the acid generator was a sulfonium salt, were not cured after heating and had fluidity. As shown in Table 2, such a tendency was the same when zirconium alkoxide was used as the metal alkoxide. From these results, it was confirmed that the progress of the curing reaction of the curable resin composition of the present invention is hardly inhibited.

1A, 1B, 1C, 1D... organic EL element, 2... element substrate, 3... sealing substrate, 4... organic layer, 4a... hole injection layer, 4b... hole transport layer, 4c... light emitting layer, 4d... electron transport layer , 5... Anode, 6... Cathode, 7... Sealing layer, 8... Sealing agent, 9... Drying agent layer, 10... Light-emitting part.

Claims (9)

containing a cationic polymerizable resin, an acid generator, and a metal alkoxide,
A curable resin composition, wherein the acid generator is a quaternary ammonium salt. 2. The curable resin composition according to claim 1, wherein the cationically polymerizable resin is an epoxy resin. The curable resin composition according to claim 1 or 2, wherein the metal alkoxide contains an alkoxy group having a cationic polymerizable group. The curable resin composition according to any one of claims 1 to 3, wherein the metal alkoxide contains a group derived from a β-diketone compound or a group derived from a β-ketoester compound. The curable resin composition according to any one of claims 1 to 4, wherein the central metal of the metal alkoxide is a Group 4 element of the periodic table, a Group 13 element of the periodic table, or a Group 14 element of the periodic table. . an element substrate;
a sealing substrate arranged opposite to the element substrate;
a light-emitting portion provided on the element substrate and having a pair of electrodes arranged to face each other and an organic layer provided therebetween;
a sealing layer provided between the element substrate and the sealing substrate for sealing the light emitting portion;
with
An organic EL device, wherein the sealing layer comprises a cured product of the curable resin composition according to any one of claims 1 to 5. 7. The organic material according to claim 6, wherein the sealing layer fills a space around the light emitting part between the element substrate and the sealing substrate while being in contact with the element substrate and the sealing substrate. EL element. The organic EL element further comprises a sealing sealant for sealing outer peripheral portions of the element substrate and the sealing substrate,
7. The organic EL device according to claim 6, wherein said sealing layer fills at least a part of the airtight space around said light emitting portion inside said sealing sealant. 7. The organic EL device according to claim 6, wherein said sealing layer has a laminated structure including a cured film containing a cured product of said curable resin composition and an inorganic film.

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