Composition for sealing electronic devices for inkjet, method for forming a film for sealing electronic devices, and film for sealing electronic devices

Abstract

The electronic device sealing composition of the present invention is an electronic device sealing composition for inkjet containing a photopolymerizable monomer and a photopolymerization initiator, wherein, as the photopolymerizable monomer, a (meth)acrylate is contained, with respect to the dynamic viscoelasticity after curing of the electronic device sealing composition, the peak value of the loss coefficient (tan δ) is in the range of 0.3 to 1.0, and the storage modulus (G') is in the range of 1.0 to 3.0 GPa.

Description

Technical Field

[0001] This invention relates to a sealing composition for inkjet-printed electronic devices, a method for forming a sealing film for electronic devices, and a sealing film for electronic devices. In particular, this invention relates to sealing compositions for electronic devices that can produce sealing films with good adhesion, flexibility, and heat resistance. Background Technology

[0002] Electronic devices, especially organic electroluminescent devices, are actively researched for their ability to achieve thinness and lightweight design. Hereinafter, organic electroluminescent devices will also be referred to as "organic EL devices" or "organic EL elements".

[0003] Furthermore, in recent years, the requirements for flexibility (bending) to foldability (foldable) and rollability (rollable) have become increasingly stringent. Therefore, the performance requirements for the bendability of organic EL devices have become increasingly stringent. Generally, when the laminates constituting the device are bent, stress concentrates at the interfaces of the laminates. Therefore, when the bendability becomes severe, delamination of the laminates can occur due to stress concentration at the interfaces. To prevent delamination, it is necessary to increase the bonding force to withstand more severe bending stresses.

[0004] In addition, with the trend towards thinner and lighter designs, it is necessary to consider the impact of the interface of the laminate and the heat generated by the device on the sealing performance.

[0005] Patent document 1 discloses a technology related to an ultraviolet-curable resin for sealing organic EL elements that can be formed by inkjet printing and whose dielectric constant of the cured product is easily reduced.

[0006] However, the inventors examined the cured material using a film-like support substrate and found that peeling of the cured material became increasingly apparent as bending increased. Furthermore, a problem was identified regarding the adhesion of the cured material.

[0007] Patent Document 2 discloses a technique for a self-healing resin composition with excellent curability under active energy rays. In particular, by using urethane acrylamide, the loss modulus (tanδ) of the cured product is specified within a specific range using a dynamic viscoelastic method, a resin composition with excellent self-healing, adhesion, and flexibility is provided.

[0008] However, the inventors confirmed the resin composition and found that the envisioned foldable and rollable repeated bending performance was insufficient, and there were problems with its adaptation to flexible organic EL devices. Furthermore, due to the use of a ladder (zipper) type crosslinking that utilizes the reversibility of intermolecular hydrogen bonds as a self-healing function, the heat resistance was insufficient.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 2020-57580

[0012] Patent Document 2: Japanese Patent Application Publication No. 2020-100821 Summary of the Invention

[0013] The problem the invention aims to solve

[0014] The present invention was made in view of the above-mentioned problems and conditions. The problem solved by the present invention is to provide an electronic device sealing composition capable of producing an electronic device sealing film with good sealing properties, flexibility, and heat resistance. Furthermore, an electronic device sealing film using the electronic device sealing composition and a method for forming the electronic device sealing film are provided.

[0015] Solution for solving the problem

[0016] In order to solve the above-mentioned problems, the inventors investigated the causes of these problems. The inventors discovered that by controlling the peak value of the loss coefficient and the storage modulus in the dynamic viscoelasticity of the cured sealing composition, it is possible to obtain an electronic device sealing film with good sealing properties, flexibility, and heat resistance.

[0017] That is, the above-mentioned problems of the present invention are solved by the following solution.

[0018] 1. A sealing composition for inkjet electronic devices, comprising a photopolymerizable monomer and a photopolymerization initiator, wherein,

[0019] As the photopolymerizable monomer, it contains (meth)acrylate.

[0020] Regarding the dynamic viscoelasticity of the cured composition for sealing electronic devices...

[0021] The peak value of the loss coefficient (tanδ) is in the range of 0.3 to 1.0, and

[0022] The energy storage modulus (G') is in the range of 1.0~3.0 GPa.

[0023] 2. The sealing composition for inkjet electronic devices according to claim 1, wherein the (meth)acrylate contains a monofunctional (meth)acrylate.

[0024] The content ratio of the monofunctional (meth)acrylate relative to the total amount of the photopolymerizable monomer is 41% by mass or more.

[0025] 3. The sealing composition for inkjet electronic devices according to claim 1, wherein the (meth)acrylate has a phenyl group.

[0026] 4. The sealing composition for inkjet electronic devices according to claim 1, wherein irradiation at 1.5~1.8 J / cm under a nitrogen atmosphere. 2 When cured by ultraviolet light with a wavelength of 395nm, the curing rate of the resulting electronic device sealing film is over 80%.

[0027] 5. A method for forming a sealing film for an electronic device, comprising forming a sealing film using the sealing composition for an electronic device according to any one of 1 to 4, comprising:

[0028] The process of forming a first sealing layer on electronic devices using a vapor phase method; and

[0029] The process of forming a second sealing layer by coating the electronic device sealing composition onto the first sealing layer.

[0030] 6. The method for forming an electronic device sealing film according to claim 5, comprising the step of forming a third sealing layer on the second sealing layer using a vapor phase method.

[0031] 7. The method for forming an electronic device sealing film according to 5, wherein the step of forming the second sealing layer is performed by inkjet printing.

[0032] 8. An electronic device sealing film, which is an electronic device sealing film for sealing electronic devices, comprising: a first sealing layer containing silicon nitride, silicon oxide, or silicon oxynitride; and

[0033] The second sealing layer is obtained using the electronic device sealing composition according to any one of 1 to 4.

[0034] 9. The electronic device sealing film according to claim 8, wherein a third sealing layer comprising silicon nitride, silicon oxide or silicon oxynitride is present on the second sealing layer.

[0035] Invention Effects

[0036] According to the above-described embodiments of the present invention, it is possible to provide an electronic device sealing composition that yields an electronic device sealing film with good adhesion, flexibility, and heat resistance. Furthermore, according to the above-described embodiments of the present invention, it is possible to provide an electronic device sealing film using the electronic device sealing composition and a method for forming the electronic device sealing film.

[0037] The mechanism by which the effects of this invention are manifested or function is not clear, but the following is a conjecture.

[0038] In this invention, suitable sealing and heat resistance can be obtained by keeping the peak value of the loss coefficient in the range of 0.3 to 1.0. It is presumably because by keeping the peak value of the loss coefficient in the range of 0.3 to 1.0, a balance can be achieved between the component that retains the energy generated by external forces and strain inside the object and the component that diffuses to the outside, thereby mitigating stress and thermal loads into dissipated (thermal) energy.

[0039] Furthermore, in this invention, by making the storage modulus (G') in the range of 1.0 to 3.0 GPa, the density of the entanglement of the polymer molecular chains is increased, thereby increasing the elastic modulus and improving the flexibility.

[0040] Furthermore, the peak loss coefficient and energy storage modulus can be kept within the preferred range by appropriately adjusting the film thickness and curing rate of the sealing film.

[0041] Furthermore, in this invention, the (meth)acrylate preferably contains a monofunctional (meth)acrylate.

[0042] Since monofunctional (meth)acrylates have only one reactive group, the molecular weight variation of the polymer during polymerization is narrowed. If the molecular weight variation is narrowed, the thermal mobility of the polymer chains becomes more uniform. Generally, it is known that the thermal mobility of polymer chains corresponds to the peak value and waveform of the loss coefficient (tanδ) of dynamic viscoelasticity; therefore, in order to ensure that the peak value of the loss coefficient is within the specified range, monofunctional (meth)acrylates are preferably used in this invention. Detailed Implementation

[0043] The electronic device sealing composition of the present invention is an inkjet electronic device sealing composition containing a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer contains (meth)acrylate, and the dynamic viscoelasticity of the electronic device sealing composition after curing has a loss coefficient (tanδ) peak value in the range of 0.3 to 1.0 and a storage modulus (G') in the range of 1.0 to 3.0 GPa.

[0044] This feature is a common or corresponding technical feature in the following embodiments.

[0045] As an embodiment of the present invention, the (meth)acrylate preferably contains a monofunctional (meth)acrylate, and the content ratio of the monofunctional (meth)acrylate relative to the total amount of the photopolymerizable monomer is 41% by mass or more. By setting this content ratio, the entanglement density of the polymer chains during the polymerization of the monofunctional (meth)acrylate is increased, and the molecular weight deviation is narrowed, thereby making the thermal mobility of the polymer chains more uniform and improving the adhesion, heat resistance, and flexibility.

[0046] From the perspective of improving the heat resistance, tightness, flexibility and heat resistance of the molecule, the (meth)acrylate preferably has a phenyl group.

[0047] From the perspective of airtightness, irradiation at 1.5~1.8 J / cm under a nitrogen atmosphere is recommended. 2 When cured by ultraviolet light with a wavelength of 395nm, the curing rate of the resulting electronic device sealing film is preferably above 80%.

[0048] (Seamless fit)

[0049] For example, when a CVD membrane exists as the substrate for a sealing membrane, it is believed that the sealing membrane peels off from the CVD membrane through interfacial peeling and agglomeration peeling. Regarding interfacial peeling, it is related to the mechanical properties and stress of the membrane. It is believed that by appropriately polymerizing and cross-linking the membrane, these mechanical properties are enhanced, and the membrane stress is within an appropriate range, thus achieving good adhesion. Furthermore, by becoming a fully cured membrane, the membrane's own strength increases, which can suppress agglomeration peeling.

[0050] Therefore, in this invention, by making the curing rate of the sealing film 80% or more, the mechanical properties of the film are improved, the stress of the film is within an appropriate range, the sealing performance is good, and since it is a fully cured film, coagulation and delamination are suppressed.

[0051] The electronic device sealing film forming method of the present invention is a method for forming a sealing film using the electronic device sealing composition of the present invention, comprising: a step of forming a first sealing layer on an electronic device by a vapor phase method; and a step of forming a second sealing layer by coating the electronic device sealing composition on the first sealing layer.

[0052] This results in sealing films for electronic devices that offer excellent sealing, flexibility, and heat resistance.

[0053] Furthermore, from the perspective of excellent sealing performance, it is preferable to include a process of forming a third sealing layer on the second sealing layer using a vapor phase method.

[0054] From the perspective of being able to form the layer with high precision, the process of forming the second sealing layer preferably uses inkjet printing.

[0055] The electronic device sealing film of the present invention is an electronic device sealing film for sealing electronic devices, comprising: a first sealing layer containing silicon nitride, silicon oxide or silicon oxynitride; and a second sealing layer using the electronic device sealing composition.

[0056] This allows for the production of sealing films for electronic devices that offer excellent sealing, flexibility, and heat resistance.

[0057] From the perspective of excellent sealing performance, it is preferable to have a third sealing layer comprising silicon nitride, silicon oxide, or silicon oxynitride on the second sealing layer.

[0058] The present invention and its constituent elements, as well as the methods and schemes for implementing the present invention, are described below. It should be noted that in this application, "~" is used to indicate the lower and upper limits of the numerical values ​​included before and after it.

[0059] [Summary of the sealing composition for electronic devices of the present invention]

[0060] The electronic device sealing composition of the present invention is an inkjet electronic device sealing composition containing a photopolymerizable monomer and a photopolymerization initiator. As the photopolymerizable monomer, it contains (meth)acrylate. Regarding the dynamic viscoelasticity of the electronic device sealing composition after curing, the peak value of the loss coefficient (tanδ) is in the range of 0.3 to 1.0, and the storage modulus (G') is in the range of 1.0 to 3.0 GPa.

[0061] Hereinafter, “composition for sealing electronic devices” will be referred to as “composition for sealing”.

[0062] In this specification, "(meth)acrylate" means at least one of acrylate and methacrylate.

[0063] Furthermore, in this invention, "electronic device" refers to a component that utilizes the kinetic energy, potential energy, etc., of electrons to generate, amplify, convert, or control electrical signals. Examples of such components include active components such as light-emitting diodes (LEDs), organic electroluminescent devices (OLEDs), photoelectric conversion devices, and transistors. Additionally, in this invention, passive components that passively perform actions such as "resistance" or "storage" from other influences, such as resistors and capacitors, are also included in the electronic device.

[0064] Therefore, the sealing composition of the present invention is used to form a sealing film for sealing the electronic device.

[0065] Regarding the dynamic viscoelasticity of the sealing composition of the present invention after curing, the peak value of the loss coefficient (tanδ) is in the range of 0.3 to 1.0. Preferably, the peak value of the loss coefficient is in the range of 0.6 to 0.8.

[0066] Regarding the dynamic viscoelasticity of the sealing composition of the present invention after curing, the storage modulus (G') is in the range of 1.0 to 3.0 GPa. Preferably, the storage modulus is in the range of 2.4 to 2.7 GPa.

[0067] Among them, "loss coefficient (loss tangent)" refers to the physical property expressed by the ratio of loss modulus G'' to energy storage modulus G' (G'' / G').

[0068] Generally speaking, the storage modulus G' (unit GPa) represents elasticity and is an indicator of the stored force that the elastic modulus will recover when deformed by external forces. That is, the storage modulus G' is the elastic response component of the elastic modulus in the relationship between strain and stress during deformation, storing energy for the work done in deformation.

[0069] On the other hand, "loss modulus G'' (unit GPa) represents viscosity and is an indicator of the force S that follows the applied force when the material deforms due to external forces, serving as a measure of heat loss."

[0070] In addition, the "loss coefficient tanδ" is an indicator representing the balance between viscosity and elasticity. That is, tanδ becomes a measure of the ratio of energy loss to energy storage for deformation work.

[0071] In this specification, "monofunctional (meth)acrylate" refers to a monomer having one (meth)acryloyl group in one molecule. "Polyfunctional (meth)acrylate" refers to a monomer having two or more (meth)acryloyl groups in one molecule.

[0072] Specifically, as a monofunctional (meth)acrylate, it is preferred to have aryl, vinyl, alkyl, hydroxyl, aldehyde, carbonyl, carboxyl, nitro, amino, sulfonyl, halogen group, ether bond, ester bond, etc., containing phenyl.

[0073] The content ratio of monofunctional (meth)acrylate relative to the total amount of photopolymerizable monomers is preferably in the range of 41 to 80% by mass, more preferably in the range of 45 to 70% by mass.

[0074] <Methods for determining peak loss coefficient (tanδ) and storage modulus (G')>

[0075] Regarding the method for determining dynamic viscoelasticity, conventionally used methods and testing conditions are preferred. For example, the following method is preferred as the testing method.

[0076] The RSA3, manufactured by TA Instruments, was used as the dynamic viscoelasticity measuring device. A tensile tool was used for sample mounting.

[0077] As a sample, a coating film of the sealing composition with a thickness of 10-20 μm was prepared on a glass substrate with dimensions of 50 mm × 50 mm under a nitrogen atmosphere. For this coating film, a nitrogen atmosphere was used with a concentration of 300 mW / cm². 2 Under these conditions, the cumulative light intensity is 1.0~1.8 J / cm². 2The coating was cured by irradiating it with ultraviolet light at a wavelength of 395nm (IST MZ 240mm 395nm UVLED). The resulting cured film (sealing film) was then peeled off from the glass substrate.

[0078] The sample was cut to a length of 40 mm and a width of 5 mm.

[0079] The dynamic viscoelasticity was measured under the following conditions: gap length 20 mm, strain 0.05%, frequency 10 Hz, temperature 0~180℃, and heating rate 5℃ / min.

[0080] (Analysis)

[0081] For the energy storage modulus G', the measured value at 25°C is used.

[0082] As an indicator of viscosity, the peak value (maximum value) of tanδ (=G'' / G': where G'' is the loss modulus) is used.

[0083] As a method for ensuring that the peak value of the loss coefficient (tanδ) is within the range of 0.3 to 1.0, one example is adjusting the type of monofunctional (meth)acrylate contained in the sealing composition. Another example is adjusting the content ratio of monofunctional (meth)acrylate relative to the total amount of photopolymerizable monomers.

[0084] Furthermore, as a method for ensuring that the storage modulus is within the range of 1.0 to 3.0 GPa, examples include adjusting the type of monofunctional (meth)acrylate contained in the sealing composition and the content ratio of monofunctional (meth)acrylate relative to the total amount of photopolymerizable monomers. Additionally, as a method, the film thickness and curing rate of the sealing film can also be adjusted.

[0085] The film thickness is preferably set in the range of 3~10μm.

[0086] <Cure Rate>

[0087] The sealing composition of the present invention was irradiated under a nitrogen atmosphere at 1.5~1.8 J / cm. 2 The curing rate of the sealing film formed by curing with ultraviolet light of wavelength 395 nm is preferably 80% or more. More preferably, the curing rate is 90% or more, with an upper limit of 100%.

[0088] Regarding the curing rate, FT-IR was measured for the sealing composition before curing and the sealing film (cured film) after light irradiation. Secondly, the peak (810 cm⁻¹) from the C=C bond of the (meth)acryloyl group in the obtained spectrum was analyzed. -1 The strength of ) can be calculated using the following formula.

[0089] Curing rate (%) = (1 - a / b) × 100

[0090] a: Peak value of the sealing composition before curing from C=C bonds

[0091] b: Peak value of the cured sealant from C=C bonds

[0092] As a method for achieving a curing rate of 80% or more, examples include the use of (meth)acrylates that readily undergo free radical reactions, photopolymerization initiators that effectively absorb 395 nm, and the increased reaction efficiency resulting from the use of sensitizers.

[0093] As meth)acrylates that readily undergo free radical reactions, amine-containing meth)acrylates and meth)acrylates with ethylene oxide can be utilized. Furthermore, hydroxyl-containing meth)acrylates and meth)acrylates with two or more functional groups can also be utilized as meth)acrylates readily undergoing free radical reactions. Additionally, since acrylates are more reactive than methacrylates, compositions with a low methacrylate ratio can be used.

[0094] The composition of the sealing composition of the present invention will be described below.

[0095] The sealing composition of the present invention comprises a photopolymerizable monomer and a photopolymerization initiator.

[0096] <Photopolymerizable monomers>

[0097] "Photopolymerizable monomers" refer to photopolymerizable monomers (also known as "photocurable monomers") that absorb light and generate active ions or free radicals, thereby enabling polymerization (curing) reactions, either by themselves or through a photopolymerization initiator. As photopolymerizable monomers, non-silicon-based monomers that do not contain silicon (Si) can be used, for example, monomers containing only elements selected from C, H, O, N, or S, but are not limited thereto. Photopolymerizable monomers can be synthesized and used through conventional synthetic methods, or they can be purchased as commercially available products.

[0098] As the photopolymerizable monomer of the present invention, it contains (meth)acrylate.

[0099] The (meth)acrylate is preferably a monofunctional (meth)acrylate, and may also contain a polyfunctional (meth)acrylate.

[0100] In addition, the (meth)acrylate preferably has an aromatic hydrocarbon group, and particularly preferably has a phenyl group.

[0101] <Monofunctional (meth)acrylates>

[0102] Regarding the monofunctional (meth)acrylates, when considering the portion where the carbon atoms are connected in the longest continuous sequence within the molecule, they include straight-chain and branched structures with two or more carbon atoms linked in a single line. It should be noted that the chain-like backbone may also contain atoms selected from O, N, or S. For example, the chain-like backbone may also contain ether bonds, thioether bonds, etc.

[0103] As such, the monofunctional (meth)acrylates of the present invention preferably have an alkylene backbone or an alkylene oxide backbone. In particular, from the viewpoint of inkjet ejection properties and flexural resistance, the monofunctional (meth)acrylates preferably have an alkylene backbone or an ethylene oxide backbone.

[0104] It should be noted that in this invention, "alkylene oxide skeleton" refers to the structure (skeleton) of a divalent linker (also called "alkylene oxide") with an oxygen atom (-O-) bonded to one end of an alkylene group.

[0105] For example, the "ethylene oxide skeleton," as an example of an "alkylene oxide skeleton," consists of a unit with two carbon chains and one oxygen atom. The ethylene oxide skeleton can have a monovalent ethylene oxide (also called an "epoxy cyclo group") structure, or it can have a structure (skeleton) with a divalent linker (also called an "ethylene oxide oxy group") formed by ring opening of the ethylene oxide cyclo group.

[0106] Specifically, monofunctional (meth)acrylates can be exemplified by mono(meth)acrylates having substituted or unsubstituted C2-C20 alkylene groups, ethylene oxides, etc.

[0107] As a monofunctional (meth)acrylate, it may include, for example, unsaturated carboxylic acid esters comprising (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, etc.; unsaturated aminoalkyl carboxylic acid esters such as 2-aminoethyl (meth)acrylate and 2-dimethylaminoethyl (meth)acrylate; saturated or unsaturated vinyl carboxylic acid esters such as vinyl acetate; cyanide vinyl compounds such as (meth)acrylonitrile; unsaturated amide compounds such as (meth)acrylamide; or mixtures thereof, but is not limited thereto.

[0108] In addition to the (meth)acrylates mentioned above, epoxy (meth)acrylates can also be listed.

[0109] The monofunctional (meth)acrylates involved in this invention may contain at least one cyclic group selected from a phenyl or phenylene group, a heterocyclic group, and a cycloalkyl group in part of a straight-chain structure or a branched structure.

[0110] The heterocyclic group can be an aromatic heterocyclic group or a non-aromatic heterocyclic group (e.g., a group having heteroatoms within a cycloalkyl skeleton).

[0111] Among the monofunctional (meth)acrylates, examples of (meth)acrylates having cycloalkyl groups include mono(meth)acrylates having substituted or unsubstituted C3-C20 cycloalkyl groups, referring to monomers having a cyclopentane backbone, cyclohexane backbone, cycloheptane backbone, bicyclic decane structure, tricyclic decane ring, adamantane ring, or isobornyl ring in the backbone. Preferably, from the viewpoint of sealing performance, the cycloalkyl group preferably contains a bicyclic decane or a tricyclic decane.

[0112] Specifically, examples of monofunctional (meth)acrylates include isoborneol (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenoxyethyl (meth)acrylate, cyclohexyl (meth)acrylate, and other alicyclic (meth)acrylates; 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, 1-adamantyl (meth)acrylate, etc.

[0113] Furthermore, in the monofunctional (meth)acrylates, (meth)acrylates having heterocyclic groups refer to monomers having heterocycles in their backbone.

[0114] As heterocyclic (heterocyclic) skeletons, specifically, as usable skeletons, dioxane structures, trioxane structures, isocyanurate structures, etc., can be listed.

[0115] Specifically, as a heterocyclic (meth)acrylate, it may include tetrahydrofurfuryl (meth)acrylate, alkoxylated tetrahydrofurfuryl acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, morpholine (meth)acrylate, ε-caprolactone-modified tris(acryloyloxyethyl)isocyanurate (M-327), pentamethylpiperidinyl methacrylate (FA-711), tetramethylpiperidinyl methacrylate (FA-712HM), cyclic trimethylolpropane formal acrylate (SR531), or mixtures thereof, but is not limited thereto.

[0116] Additionally, among the monofunctional (meth)acrylates, as (meth)acrylates having one phenyl or one phenylene group, benzyl (meth)acrylate, ethoxy-modified cresol (meth)acrylate, propoxy-modified cresol (meth)acrylate, neopentyl glycol benzoate (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxy-polyethylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-acryloyloxyethyl-phthalic acid, neopentyl glycol-acrylate-benzoate, nonylphenol ethylene oxide (meth)acrylate, nonylphenol propylene oxide (meth)acrylate, or mixtures thereof, but are not limited thereto.

[0117] In the monofunctional (meth)acrylate, the heterocyclic (heterocyclic) skeleton preferably includes a dioxanediol group, and the phenyl group preferably includes phenoxyethyl, phenoxydiethylene glycol, or nonylphenol oxyethylidene. Thus, due to the planar structure of the molecule, the compound is stabilized, exhibiting excellent heat resistance, sealing performance, and adhesion.

[0118] In this invention, the preferred monofunctional (meth)acrylates are o-phenylphenoxyethyl acrylate (compound a-1 below), nonylphenol EO modified acrylate (compound a-2 below), phenoxy diethylene glycol acrylate (compound a-3 below), stearyl acrylate (compound a-4 below), isobornyl acrylate (compound a-5 below), 4-phenylbenzyl acrylate (compound a-6 below), etc.

[0119] Furthermore, the monofunctional (meth)acrylates involved in this invention preferably have an aromatic hydrocarbon group, and particularly preferably have a phenyl group.

[0120] Examples of monofunctional (meth) acrylates containing phenyl groups include o-phenylphenoxyethyl acrylate (compound a-1), nonylphenol EO-modified acrylate (compound a-2), phenoxydiethylene glycol acrylate (compound a-3), and 4-phenylbenzyl acrylate (compound a-6).

[0121] [Chemistry 1]

[0122]

[0123] The monofunctional (meth)acrylate involved in this invention preferably contains 41% by mass or more of the total amount of photopolymerizable monomers. This content is particularly more preferably in the range of 50% to 75% by mass.

[0124] <Polyfunctional (meth)acrylates>

[0125] Regarding the polyfunctional (meth)acrylates involved in this invention, when considering the portion where the carbon atoms are longest continuously connected within the molecule, they include straight-chain structures and branched structures in which two or more carbon atoms are connected in a row. It should be noted that the chain-like backbone may contain atoms selected from O, N, or S. For example, the chain-like backbone may contain ether bonds, thioether bonds, etc.

[0126] As such, the polyfunctional (meth)acrylates involved in this invention, like the monofunctional (meth)acrylates, may also have an alkylene backbone or an alkylene oxide backbone.

[0127] In addition, as a polyfunctional (meth)acrylate involved in the present invention, similarly to the monofunctional (meth)acrylate, it may also contain at least one cyclic group selected from a phenyl or phenylene group, a heterocyclic group, and a cycloalkyl group in part of the straight-chain structure or branched structure.

[0128] Specific examples of multifunctional (meth)acrylates include di(meth)acrylates, tri(meth)acrylates, tetra(meth)acrylates, etc., having substituted or unsubstituted C2-C20 alkylene groups, ethylene oxides, etc. In particular, from the viewpoint of inkjet ejection properties and flexural resistance over time, it is preferable to select ethylene glycol di(meth)acrylates having a structure represented by the following general formula (1) or di(meth)acrylates having 6 to 10 carbon atoms in the alkylene backbone.

[0129] It should be noted that triethylene glycol di(meth)acrylate is particularly preferred among ethylene glycol di(meth)acrylates having the structure represented by the following general formula (1).

[0130] [Chemistry 2]

[0131]

[0132] As a multifunctional (meth)acrylate, it may include, for example, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, pentaethylene glycol di(meth)acrylate, hexaethylene glycol di(meth)acrylate, polytetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol diacrylate, 1,12-dodecanediol dimethacrylate, octanediol di(meth)acrylate, nonanediol di(meth)acrylate, decanediol di(meth)acrylate, undecanediol di(meth)acrylate, dodecanediol di(meth)acrylate, etc. Di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, hexyl di(meth)acrylate, decyl di(meth)acrylate, dodecyl dimethacrylate, ethoxylated glycerol tri(meth)acrylate, stearyl (meth)acrylate, 2-hydroxy-1,3-dimethylacryloyloxypropane, polyethylene glycol #600 di(meth)acrylate, or mixtures thereof, but not limited thereto.

[0133] Examples of the polyfunctional (meth)acrylates involved in this invention include triethylene glycol diacrylate (compound a-7 below), triethylene glycol dimethacrylate (compound a-8 below), decyl diacrylate (compound a-9 below), and tricyclodecanediethanol diacrylate (compound a-10 below).

[0134] [Chemistry 3]

[0135]

[0136] From the viewpoint of suitable loss coefficient (tanδ) and storage modulus (G'), the content ratio of the polyfunctional (meth)acrylate to the total amount of photopolymerizable monomers involved in this invention is preferably in the range of 25 to 59% by mass. More preferably, this content ratio is in the range of 25 to 40% by mass.

[0137] <Photopolymerization Initiator>

[0138] The photopolymerization initiator is not particularly limited to any common photopolymerization initiator capable of photocuring reaction.

[0139] As photopolymerization initiators, they may include, for example, triazine-based, acetophenone-based, benzophenone-based, thioxanone-based, benzoin-based, phosphorus-based, oxime-based, or mixtures thereof.

[0140] Triazine initiators can be 2,4,6-trichlorotriazine, 2-phenyl-4,6-bis(trichloromethyl)triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)triazine, 2-(4'-methoxynaphthyl)-4,6-bis(trichloromethyl)triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)triazine, etc. Triazine, 2-biphenyl-4,6-bis(trichloromethyl)triazine, bis(trichloromethyl)-6-styryltriazine, 2-(naphthyl-1-yl)-4,6-bis(trichloromethyl)triazine, 2-(4-methoxynaphthyl-1-yl)-4,6-bis(trichloromethyl)triazine, 2,4-trichloromethyl(piperyl)-6-triazine, 2,4-(trichloromethyl(4'-methoxystyryl)-6-triazine or mixtures thereof.

[0141] The acetophenone initiator can be 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylacetophenone, p-tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'-dichloro-4-phenoxyacetophenone, 2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butane-1-one, and mixtures thereof.

[0142] The benzophenone-based initiator can be benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, or acryloylbenzophenone. Alternatively, the benzophenone-based initiator can be 4,4'-bis(dimethylamino)benzophenone, 4,4'-dichlorobenzophenone, or 3,3'-dimethyl-2-methoxybenzophenone. Furthermore, the benzophenone-based initiator can be a mixture of the aforementioned substances.

[0143] The thioxanthone-based initiator can be thioxanthone, 2-methylthioxanthone, or isopropylthioxanthone. Alternatively, the thioxanthone-based initiator can be 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, or 2-chlorothioxanthone. Furthermore, the thioxanthone-based initiator can be a mixture of the aforementioned substances.

[0144] The benzoin-based initiator can be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, or a mixture thereof.

[0145] The phosphorus-based initiator may be bisbenzoylphenylphosphine oxide, benzoyldiphenylphosphine oxide, or a mixture thereof.

[0146] The oxime system can be 2-(o-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione. Alternatively, the oxime system can be 1-(o-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethyl ketone. Furthermore, the oxime system can be a mixture of the aforementioned substances.

[0147] Preferred commercially available photopolymerization initiators include IRGACURE 819 (registered trademark): bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by BASF).

[0148] In the sealing composition of the present invention, the photopolymerization initiator is preferably contained in the range of about 0.1 to 20 parts by mass relative to a total of 100 parts by mass of the photopolymerizable monomer and the photopolymerization initiator. By including it within this range, photopolymerization occurs sufficiently during exposure, and after photopolymerization, a decrease in transmittance due to residual unreacted initiator can be prevented.

[0149] Specifically, the photopolymerization initiator is preferably contained in the range of 0.5 to 10 parts by weight, and more specifically in the range of 1 to 5 parts by weight.

[0150] In the sealing composition of the present invention, the photopolymerization initiator is preferably contained in the range of 0.1 to 10% by mass, more preferably in the range of 0.1 to 5% by mass, based on the solid content. By containing it within this range, photopolymerization can occur sufficiently, and a decrease in transmittance due to residual unreacted initiator can be prevented.

[0151] Alternatively, photoacid-producing agents or photopolymerization initiators such as carbazole-based, diketone-based, sulfonium-based, iodonium-based, diazo-based, and biimidazole-based agents can be used instead of the aforementioned photopolymerization initiator.

[0152] <Other Additives>

[0153] The sealing composition of the present invention may further contain other components, including antioxidants, heat stabilizers, photosensitizers, dispersants, thermal crosslinking agents, surfactants, and polymerization inhibitors, within the range to achieve the effects of the present invention. Regarding these components, the sealing composition of the present invention may contain only one or more of these components.

[0154] The antioxidant can improve the thermal stability of the sealing layer. The antioxidant may contain one or more of the following: phenolic, quinone, amine, and phosphite-based antioxidants, but is not limited to these. Examples of antioxidants include tetratetra[methylene(3,5-di-tert-butyl-4-hydroxycinnamate)]methane and tris(2,4-di-tert-butylphenyl) phosphite.

[0155] In the sealing composition, the antioxidant is preferably contained in the range of 0.01 to 3 parts by mass relative to a total of 100 parts by mass of the photopolymerizable monomer and the photopolymerization initiator. More preferably, the antioxidant is contained in the sealing composition in the range of 0.01 to 1 part by mass. By including it within this range, excellent thermal stability can be exhibited.

[0156] Regarding the heat stabilizer, it is a substance contained in the sealing composition that suppresses viscosity changes of the sealing composition at room temperature, and conventional heat stabilizers can be used without limitation.

[0157] For example, sterically hindered phenolic heat stabilizers can be used as heat stabilizers. Specifically, such heat stabilizers may include poly(dicyclopentadiene-co-p-cresol), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6-di-tert-butyl-4-methylphenol, 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 6,6'-di-tert-butyl-2,2'-thiodi-p-cresol, tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, triethylene glycol-bis(3-tert-butyl-4-hydroxy-5-methylphenyl), 4,4'-thiobis(6-tert-butyl-m-cresol), 3,3'-bis(3- The following are not limited to one or more of the following: (5-di-tert-butyl-4-hydroxyphenyl)-N,N'-hexamethylene-dipropionamide, pentaerythritol tetra(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), stearyl-3,5-di-tert-butyl-4-hydroxyphenylpropionate, pentaerythritol tetra(1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butyl-benzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, and 1,3,5-tris(2-hydroxyethyl)isocyanurate-tris(3,5-di-tert-butyl-hydroxyphenylpropionate).

[0158] In the sealing composition, based on the solid content, it is preferable to contain 2000 ppm or less of the heat stabilizer relative to the total amount of the photocurable monomer and the photopolymerization initiator. Specifically, the heat stabilizer is preferably contained in the range of 0.01 to 2000 ppm, more preferably in the range of 100 to 1000 ppm. By placing it within this range, the heat stabilizer can further improve the storage stability and processability of the sealing composition in its liquid state.

[0159] The photosensitizer has the function of transferring absorbed light energy to the photopolymerization initiator. Therefore, it is a compound that can retain its original photopolymerization initiator function even if the photopolymerization initiator does not have absorption corresponding to the light from the light source.

[0160] As photosensitizers, examples include anthracene derivatives such as 9,10-dibutoxyanthracene; benzoin derivatives such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, and 4-benzoyl-N,N-dimethyl-N-[2-(1 [-oxo-2-propenoxy)ethyl]benzylmethylammonium bromide (Metanaminium bromide), (4-benzoylbenzyl)trimethylammonium chloride and other benzophenone derivatives; 2-isopropylthioxanthione, 4-isopropylthioxanthione, 2,4-diethylthioxanthione, 2,4-dichlorothioxanthione, 1-chloro-4-propoxythioxanthione, 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthione-9-onemethyl chloride (Mesochlorolide) and other thioxanthione derivatives; and other compounds. Among these, anthracene derivatives, benzoin derivatives, benzophenone derivatives, anthraquinone derivatives, and thioxanthione derivatives are preferred as photosensitizers.

[0161] As a polymerization inhibitor, the preferred inhibitors are any one of N-oxygen-based inhibitors, phenolic inhibitors containing o-tert-butyl groups, or inhibitors having two or more aromatic rings. N-oxygen-based inhibitors are particularly preferred.

[0162] Commercially available N-oxygen-based polymerization inhibitors include IRGASAB (registered trademark) UV10 (manufactured by BASF), etc.

[0163] UV curing

[0164] Preferably, the sealing composition of the present invention is in the range of 10 to 500 mW / cm. 2 It can be cured by irradiating it with ultraviolet light for 1 to 100 seconds within a certain range, but it is not limited to this range.

[0165] From the perspective of preventing the degradation of electronic devices, 395nm LEDs are preferred as ultraviolet light sources.

[0166] <Physical properties>

[0167] The viscosity of the sealing composition of the present invention is preferably in the range of 3 to 30 mPa·s. With a viscosity within this range, the ejection performance from the inkjet head can be further improved.

[0168] Regarding the surface tension of the sealing composition of the present invention, from the viewpoint of further improving the ejection performance from the inkjet head, it is preferably 15 mN / m or more and less than 45 mN / m.

[0169] The viscosity of the sealing composition of the present invention can be determined, for example, by measuring the temperature change of the dynamic viscoelasticity of the sealing composition using various rheometers.

[0170] In this invention, these viscosities are obtained by the following method.

[0171] The sealing composition of the present invention was applied to a stress-controlled rheometer Physica MCR300 (diameter of cone plate: 75 mm, cone angle: 1.0°), manufactured by Anton Paar.

[0172] Next, the sealing composition is heated to 100°C, and then cooled to 20°C at a cooling rate of 0.1°C / s, a strain of 5%, and an angular frequency of 10 radian / s to obtain a dynamic viscoelastic temperature change curve.

[0173] The sealing composition of the present invention may contain pigment particles.

[0174] The average particle size of the pigment particles in the sealing composition of the present invention is preferably in the range of 0.08 to 0.5 μm, and the maximum particle size is preferably in the range of 0.3 to 10 μm. By including the pigment particles in the sealing composition, the ejection performance from the inkjet head can be further improved.

[0175] The average particle size of the pigment particles in this invention refers to the value obtained by dynamic light scattering method using a DataSizer Nano ZSP manufactured by Malvern. It should be noted that, due to the high concentration of the sealing composition containing the coloring material, light is not transmitted through this measuring device; therefore, the sealing composition was diluted 200 times before measurement. The measurement temperature was set to room temperature (25°C).

[0176] Regarding the sealing composition of the present invention, it is preferable that its density ρ, surface tension σ, viscosity μ, and Oh number (expressed by Formula 1 below, represented by the nozzle diameter D0) are in the range of 0.1 to 1. This results in excellent inkjet ejection properties and droplet stabilization during ink flight.

[0177] Preferably, the sealing composition of the present invention is prepared by providing a cured polymer having a Tg (glass transition temperature) of 80°C or higher in the polymerized film. From the viewpoint of ensuring stability in electronic device fabrication processes, driving temperatures, and reliability tests, the Tg of the polymerized film is preferably 80°C or higher.

[0178] [Method for forming sealing films for electronic devices]

[0179] The electronic device sealing film forming method of the present invention is a method for forming a sealing film using the above-described electronic device sealing composition of the present invention, comprising: a step of forming a first sealing layer on an electronic device using a vapor phase method; and a step of forming a second sealing layer by coating the electronic device sealing composition onto the first sealing layer.

[0180] Furthermore, from the viewpoint of further improving the sealing performance of electronic devices, it is preferable to include a process of forming a third sealing layer on the second sealing layer using a vapor phase method.

[0181] <First sealing layer formation process>

[0182] Regarding the first sealing layer formation process, the first sealing layer is formed on electronic devices using a vapor phase method.

[0183] Examples of vapor-phase methods include sputtering, vapor deposition, thermal CVD, and catalytic chemical vapor deposition (Cat-CVD). Other examples of vapor-phase methods include capacitively coupled plasma CVD (CCP-CVD), photocatalytic CVD, plasma CVD (PECVD), epitaxial growth, atomic layer deposition (ALD), and chemical vapor deposition. Among these, ALD and CVD methods are preferred.

[0184] The sputtering methods include reactive sputtering methods such as magnetron cathode sputtering, flat-plate magnetron sputtering, bipolar AC flat-plate magnetron sputtering, and bipolar AC rotating magnetron sputtering.

[0185] The vapor deposition methods include, for example, resistance heating vapor deposition, electron beam vapor deposition, ion beam vapor deposition, and plasma-assisted vapor deposition.

[0186] The first sealing layer contains silicon nitride (SiNx), silicon oxynitride (SiNOx), or silicon oxide (SiOx).

[0187] As a specific example of forming the first sealing layer, the following method can be listed: the chamber is depressurized, and silane (SiH4), ammonia (NH3), and hydrogen (H2) are heated and supplied into the chamber as raw material gases to form the first sealing layer.

[0188] The thickness of the first sealing layer is preferably in the range of 10 to 1000 nm, and more preferably in the range of 100 to 500 nm.

[0189] <Second sealing layer formation process>

[0190] In the process of forming the second sealing layer, the second sealing layer is formed by coating the sealing composition of the present invention onto the first sealing layer.

[0191] Specifically, the process includes the following steps: applying the sealing composition to the first sealing layer (coating step), and curing the resulting coating film under a nitrogen atmosphere by ultraviolet irradiation. Alternatively, a step of modifying the coating by vacuum ultraviolet irradiation may also be included.

[0192] (Coating process)

[0193] Any suitable method can be used as the coating method for the sealing composition. Examples of such coating methods include spin coating, roller coating, flow coating, inkjet coating, spray coating, printing, dip coating, casting film formation, bar coating, and gravure printing. Among these, inkjet coating is preferred from the viewpoint that it can perform the required fine patterning as needed when sealing electronic devices such as organic EL elements.

[0194] As an inkjet printing method, it is possible to use known methods.

[0195] Inkjet printing methods are broadly divided into two types: on-demand dripping and continuous inkjet printing. Either method can be used.

[0196] As a method of on-demand dripping, there are electro-mechanical conversion, electro-thermal conversion, electrostatic attraction, and discharge methods.

[0197] As electromechanical conversion methods, examples include single-cavity type, dual-cavity type, curved type, piston type, shared mode type, and shared wall type.

[0198] Examples of electro-thermal conversion methods include thermal inkjet and BUBBLEJET (registered trademark) types.

[0199] Examples of electrostatic attraction methods include electric field-controlled and slit-jet types.

[0200] Examples of discharge methods include spark jetting.

[0201] From the perspective of inkjet head cost and productivity, it is preferable to use inkjet heads that use electro-mechanical conversion or electro-thermal conversion.

[0202] It should be noted that the method of making droplets (such as coating liquid) fall by inkjet is sometimes called "inkjet printing".

[0203] When applying the sealing composition, it is preferable to do so under a nitrogen atmosphere.

[0204] (Curing process)

[0205] In the curing process, after the coating process, the resulting coating film is irradiated with ultraviolet light under a nitrogen atmosphere.

[0206] Regarding the ultraviolet irradiance received by the coated film on its surface, it is preferably between 10 and 500 mW / cm². 2 It can be cured by irradiating within a range of 1 to 100 seconds, but is not limited to this range.

[0207] From the perspective of preventing the degradation of electronic devices, 395nm LEDs are preferred as ultraviolet light sources.

[0208] (Modification process)

[0209] Modification treatment can also be performed during the second sealing layer formation process.

[0210] In the modification process, after the coating process, the obtained coating film is subjected to vacuum ultraviolet irradiation under a nitrogen atmosphere to perform modification treatment.

[0211] The so-called modification treatment refers to the conversion reaction of polysilazane into silicon oxide or silicon oxynitride. The modification treatment is also carried out under nitrogen atmosphere and reduced pressure in a glove box.

[0212] The modification treatment in this invention can be selected from known methods based on the conversion reaction of polysilazane. In this invention, plasma, ozone, and ultraviolet conversion reactions capable of being carried out at low temperatures are preferred. For plasma and ozone, conventionally known methods can be used.

[0213] In this invention, the coating film is preferably irradiated with vacuum ultraviolet light (also known as VUV) with a wavelength of less than 200 nm to perform modification treatment, thereby forming the second sealing layer involved in this invention.

[0214] The thickness of the second sealing layer is preferably in the range of 0.5 to 10 μm, and more preferably in the range of 3 to 10 μm.

[0215] The entire layer in the second sealing layer can be a modified layer, and the thickness of the modified layer after modification is preferably in the range of 1 to 50 nm, more preferably in the range of 1 to 30 nm.

[0216] In the process of modifying the coating by irradiation with the vacuum ultraviolet light, the irradiance of the vacuum ultraviolet light on the surface of the coating film is preferably 30~200 mW / cm. 2 Within this range. More preferably, the irradiance of this vacuum ultraviolet light is 50~160 mW / cm². 2 Within the range.

[0217] By setting the irradiance of vacuum ultraviolet light to 30 mW / cm 2 The above methods can significantly improve modification efficiency. This is achieved under vacuum ultraviolet irradiance of 200 mW / cm².2 The following methods can greatly suppress the damage rate to the coating film and also reduce damage to the substrate.

[0218] Regarding vacuum ultraviolet irradiation, the preferred irradiation energy for the coated film surface is 1~10 J / cm. 2 Within a certain range. From the viewpoint of maintaining barrier properties and resistance to damp heat for dehumidification, the irradiation energy is more preferably 3~7 J / cm². 2 Within the range.

[0219] It should be noted that rare gas excimer lamps are preferred as the light source for vacuum ultraviolet light.

[0220] Because vacuum ultraviolet light absorbs oxygen, its efficiency is easily reduced during the irradiation process. Therefore, it is preferable to perform vacuum ultraviolet irradiation with the lowest possible oxygen concentration. Specifically, the oxygen concentration during vacuum ultraviolet irradiation is preferably set in the range of 10 to 10,000 ppm. More preferably, the oxygen concentration is in the range of 50 to 5,000 ppm, and even more preferably, in the range of 80 to 4,500 ppm. Most preferably, the oxygen concentration is in the range of 100 to 1,000 ppm.

[0221] Modification treatment can be combined with heat treatment.

[0222] As for the heating conditions, the process is preferably carried out at a temperature in the range of 50 to 300°C, more preferably in the range of 60 to 150°C, for a period of 1 second to 60 minutes, and more preferably 10 seconds to 10 minutes. By using heat treatment, the dehydration condensation reaction during modification can be promoted, and the modified body can be formed more efficiently.

[0223] Examples of heat treatments include methods that heat the coating film by contacting the substrate with a heating element such as a heating block, and methods that heat the atmosphere using an external heater based on resistance wires. Additionally, methods that utilize light in the infrared region, such as IR heaters, can be used as examples of such heat treatments, but these are not particularly limited. Furthermore, methods that maintain the smoothness of the coating film containing the silicon compound can be appropriately selected.

[0224] <Third sealing layer formation process>

[0225] Regarding the process of forming the third sealing layer, the third sealing layer is formed on the second sealing layer by a vapor phase method.

[0226] As a vapor phase method, similar to the vapor phase method used in the first sealing layer formation process, examples include sputtering, vapor deposition, thermal CVD, and catalytic chemical vapor deposition (Cat-CVD). Furthermore, examples of the vapor phase method include capacitively coupled plasma CVD (CCP-CVD), photo-CVD, plasma CVD (PE-CVD), epitaxial growth, atomic layer growth (ALD), and chemical vapor deposition. Among these, ALD and CVD methods are preferred.

[0227] The sputtering methods include reactive sputtering methods such as magnetron cathode sputtering, flat-plate magnetron sputtering, bipolar AC flat-plate magnetron sputtering, and bipolar AC rotating magnetron sputtering.

[0228] The vapor deposition methods include, for example, resistance heating vapor deposition, electron beam vapor deposition, ion beam vapor deposition, and plasma-assisted vapor deposition.

[0229] The third sealing layer contains silicon nitride (SiNx), silicon oxynitride (SiNOx), or silicon oxide (SiOx).

[0230] As a specific example of forming the third sealing layer, the following method can be listed: the chamber is depressurized, and silane (SiH4), ammonia (NH3), and hydrogen (H2) are heated and supplied into the chamber as raw material gases to form the third sealing layer.

[0231] The thickness of the third sealing layer is preferably in the range of 10 to 1000 nm, and more preferably in the range of 100 to 500 nm.

[0232] It should be noted that after forming the sealing film as described above, a conductive film for the touch sensor can be further formed.

[0233] The conductive film can be composed, for example, of a metal compound film such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). Alternatively, the conductive film can be composed of highly flexible graphene films or metal nanowire films (e.g., films containing silver or copper nanowires). Furthermore, the conductive film can be composed of metal nanoparticle films (e.g., films containing silver or copper nanoparticles). Additionally, the conductive film can be composed of a multi-metal laminate, such as an Al film / Ti film / Al film.

[0234] [Sealing film for electronic components]

[0235] The electronic device sealing film of the present invention is an electronic device sealing film for sealing electronic devices, comprising: a first sealing layer containing silicon nitride, silicon oxide, or silicon oxynitride; and a second sealing layer using the electronic device sealing composition of the present invention.

[0236] The electronic device sealing film of the present invention is formed by the electronic device sealing film forming method. That is, a second sealing layer is formed using the electronic device sealing composition of the present invention.

[0237] In addition, the electronic device sealing film of the present invention preferably has a third sealing layer containing silicon nitride, silicon oxide or silicon oxynitride on the second sealing layer.

[0238] <First sealing layer>

[0239] The first sealing layer is a layer formed on the electronic device by the vapor phase method. Specifically, it contains silicon nitride, silicon oxide (silicon monoxide, silicon dioxide, etc.), or silicon oxynitride.

[0240] <Second sealing layer>

[0241] The second sealing layer is disposed adjacent to the first sealing layer and is formed by applying the sealing composition onto the first sealing layer.

[0242] Therefore, the second sealing layer contains a polymer formed from the photopolymerizable monomer. Preferably, the photopolymerizable monomer contains monofunctional (meth)acrylates and further polyfunctional (meth)acrylates.

[0243] As a method for detecting that the second sealing layer contains the polymer, various conventionally known analytical methods can be used, such as chromatography, infrared spectroscopy, ultraviolet-visible spectroscopy, nuclear magnetic resonance analysis, X-ray diffraction, mass analysis, X-ray photoelectron spectroscopy, etc.

[0244] The polymer content in the second sealing layer is preferably in the range of 85-100% by mass, more preferably in the range of 90-95% by mass.

[0245] <Third sealing layer>

[0246] The third sealing layer is disposed adjacent to the second sealing layer and is formed using the vapor phase method. Specifically, similar to the first sealing layer, it contains silicon nitride, silicon oxide (silicon monoxide, silicon dioxide, etc.), or silicon oxynitride.

[0247] [Electronic Components]

[0248] In the electronic device sealing film forming method and the electronic device sealing film of the present invention, the electronic device to be sealed can be, for example, an organic EL element, an LED element, or a liquid crystal display element (LCD). Other examples of such electronic devices include thin-film transistors, touch panels, electronic paper, and solar cells (PV). From the viewpoint of obtaining the effects of the present invention more efficiently, the electronic device is preferably an organic EL element, a solar cell, or an LED element, and particularly preferably an organic EL element.

[0249] <Organic EL Components>

[0250] The organic EL element used in the electronic device involved in this invention can be a bottom-emitting type, that is, an organic EL element configured to extract light from the transparent substrate side.

[0251] Specifically, for bottom-emitting types, it is constructed by sequentially stacking a transparent electrode that serves as a cathode, a light-emitting functional layer, and a counter electrode that serves as an anode on a transparent substrate.

[0252] In addition, the organic EL element involved in the present invention can be a top-emitting type, that is, an organic EL element configured to extract light from the transparent electrode side that serves as the cathode, opposite to the substrate.

[0253] Specifically, for top-emitting types, a counter electrode serving as the anode is provided on the substrate side, and a light-emitting functional layer and a transparent electrode serving as the cathode are sequentially stacked on its surface. The following shows a representative example of the structure of an organic EL element.

[0254] (i) Anode / hole injection transport layer / light-emitting layer / electron injection transport layer / cathode

[0255] (ii) Anode / hole injection transport layer / light-emitting layer / hole blocking layer / electron injection transport layer / cathode

[0256] (iii) Anode / hole injection transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron injection transport layer / cathode

[0257] (iv) Anode / Hole Injection Layer / Hole Transport Layer / Light Emitting Layer / Electron Transport Layer / Electron Injection Layer / Cathode

[0258] (v) Anode / Hole Injection Layer / Hole Transport Layer / Light Emitting Layer / Hole Blocking Layer / Electron Transport Layer / Electron Injection Layer / Cathode

[0259] (vi) Anode / Hole Injection Layer / Hole Transport Layer / Electron Blocking Layer / Light Emitting Layer / Hole Blocking Layer / Electron Transport Layer / Electron Injection Layer / Cathode

[0260] Furthermore, organic EL devices can have a non-luminescent intermediate layer. This intermediate layer can be a charge-generating layer or a multiphoton unit structure.

[0261] For an overview of organic EL elements applicable to the present invention, examples include Japanese Patent Application Publication Nos. 2013-157634, 2013-168552, 2013-177361, 2013-187211, 2013-191644, 2013-191804, 2013-225678, 2013-235994, and 2013-2 The structures described in Japanese Patent Application Publication No. 43234, Japanese Patent Application Publication No. 2013-243236, Japanese Patent Application Publication No. 2013-242366, Japanese Patent Application Publication No. 2013-243371, Japanese Patent Application Publication No. 2013-245179, Japanese Patent Application Publication No. 2014-003249, Japanese Patent Application Publication No. 2014-003299, Japanese Patent Application Publication No. 2014-013910, Japanese Patent Application Publication No. 2014-017493, and Japanese Patent Application Publication No. 2014-017494.

[0262] <Substrate>

[0263] As a substrate suitable for use in the organic EL element, glass or resin film is preferably used, with resin film being preferred where flexibility is required. It should be noted that the substrate will also be referred to below as a support substrate, matrix, base, support body, etc.

[0264] Furthermore, the substrate can be either transparent or opaque. In the case of a so-called bottom-emission type where light is emitted from the substrate side, the substrate is preferably transparent.

[0265] Preferred resins include base materials comprising polyester resins, methacrylic resins, methacrylic acid-maleic acid copolymers, polystyrene resins, transparent fluoropolymers, polyimides, fluorinated polyimides, polyamide resins, polyamide-imides, polyetherimides, acylated cellulose resins, polyurethane resins, polyetheretherketone resins, polycarbonate resins, alicyclic polyolefin resins, polyarylate resins, polyethersulfone resins, polysulfone resins, cycloolefin copolymers, fluorene-modified polycarbonate resins, alicyclic modified polycarbonate resins, fluorene-modified polyester resins, and acryloyl compounds. This resin can be used alone or in combination of two or more.

[0266] The substrate preferably contains a heat-resistant material. Specifically, a substrate with a coefficient of linear expansion of 15 ppm / K or higher and 100 ppm / K or lower, and a glass transition temperature (Tg) of 100°C or higher and 300°C or lower is used.

[0267] This substrate meets the necessary conditions for use as a laminated film in electronic components and displays. Specifically, when using the sealing film of this invention in these applications, the substrate is sometimes exposed to processes exceeding 150°C. If the coefficient of linear expansion of the substrate exceeds 100 ppm / K, the substrate dimensions become unstable during transport in processes at such temperatures, and with thermal expansion and contraction, it is prone to deterioration of barrier properties or inability to withstand hot processes. If it is less than 15 ppm / K, the film may sometimes crack like glass, resulting in deterioration of flexibility.

[0268] The Tg and coefficient of linear expansion of the substrate can be adjusted by additives, etc.

[0269] More preferred examples of thermoplastic resins that can be used as substrates include, for example, polyethylene terephthalate (PET: 70°C), polyethylene naphthalate (PEN: 120°C), polycarbonate (PC: 140°C), alicyclic polyolefins (e.g., ZEONOR 1600 (registered trademark) manufactured by Zeon Corporation of Japan: 160°C), polyarylates (PAr: 210°C), polyethersulfone (PES: 220°C), polysulfone (PSF: 190°C), and cyclic olefin copolymers (COC: as stated in Japanese Patent Application Publication No. 2001-150584). Compounds loaded with polyimide (e.g., manufactured by Mitsubishi Gas Chemical Co., Ltd., Neoprim (registered trademark): 260°C), fluorene-modified polycarbonate (BCF-PC: compound described in Japanese Patent Application Publication No. 2000-227603: 225°C), alicyclic-modified polycarbonate (IP-PC: compound described in Japanese Patent Application Publication No. 2000-227603: 205°C), acryloyl compounds (compound described in Japanese Patent Application Publication No. 2002-80616: 300°C and above), etc. (temperature in parentheses indicates Tg).

[0270] Since the electronic devices involved in this invention are organic EL elements or other electronic devices, the substrate is preferably transparent. That is, the light transmittance is typically 80% or more, preferably 85% or more, and more preferably 90% or more.

[0271] Light transmittance can be measured using the method described in JIS K7105:1981, namely, using an integrating sphere light transmittance measuring device to measure the total light transmittance and the amount of scattered light, and then calculated by subtracting the diffusion transmittance from the total light transmittance.

[0272] In addition, the substrates listed above can be either unstretched films or stretched films.

[0273] The substrate can be manufactured using conventionally known methods. The methods for manufacturing these substrates can be appropriately described in paragraphs “0051” to “0055” of International Publication No. 2013 / 002026.

[0274] The surface of the substrate can be treated with various known methods to improve adhesion, such as corona discharge treatment, flame treatment, oxidation treatment, or plasma treatment, and these treatments can be combined as needed. Additionally, the substrate can be treated to improve adhesion.

[0275] The substrate can be a single layer or a laminated structure of two or more layers. When the substrate is a laminated structure of two or more layers, the substrates can be of the same type or different types.

[0276] The thickness of the substrate involved in this invention (the total thickness in the case of a laminated structure of two or more layers) is preferably 10 to 200 μm, more preferably 20 to 150 μm.

[0277] Furthermore, in the case of a membrane substrate, a membrane substrate with a gas barrier layer is preferred.

[0278] Regarding the gas barrier layer for the membrane substrate, an inorganic material, an organic material, or a mixture of both can be formed on the surface of the membrane substrate.

[0279] In addition, the gas barrier layer preferably has a water vapor permeability (25±0.5℃, relative humidity (90±2)%RH) of 0.01 g / m. 2 • Barrier membranes with a lifespan of less than 24 hours.

[0280] The water vapor permeability was measured using the method according to JIS K 7129-1992.

[0281] Furthermore, the gas barrier layer is preferably characterized by an oxygen permeability of 1×10⁻⁶. -3 mL / m 2 • 24h·atm or less, water vapor transmittance of 1×10 -3 g / m 2 • High gas barrier membrane with a lifespan of less than 24 hours.

[0282] The oxygen permeability was measured using the method according to JIS K 7126-1987.

[0283] The material used to form the gas barrier layer can be any material that can inhibit the intrusion of substances such as moisture and oxygen that cause component deterioration. Examples of suitable materials include silicon monoxide, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, and silicon carbide.

[0284] There are no particular limitations on the gas barrier layer. For example, in the case of an inorganic gas barrier layer such as silicon monoxide, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, or silicon carbide, it is preferable to form the layer by means of sputtering (e.g., magnetron cathode sputtering, flat-plate magnetron sputtering, bipolar AC flat-plate magnetron sputtering, bipolar AC rotating magnetron sputtering, etc.), vapor deposition (e.g., resistance heating vapor deposition, electron beam vapor deposition, ion beam vapor deposition, plasma-assisted vapor deposition, etc.), thermal CVD, catalytic chemical vapor deposition (Cat-CVD), capacitively coupled plasma CVD (CCP-CVD), photo-CVD, plasma CVD (PE-CVD), epitaxial growth, atomic layer growth (ALD), reactive sputtering, and other chemical vapor deposition methods.

[0285] The formation of inorganic gas barrier layers can be exemplified by the following methods: after coating a substrate with an inorganic precursor such as polysilazane and tetraethyl orthosilicate (TEOS), the substrate is modified by irradiation with vacuum ultraviolet light.

[0286] In addition, inorganic gas barrier layers can also be formed through film metallization techniques such as metallization of resin substrates and bonding of metal foils to resin substrates.

[0287] In addition, the inorganic gas barrier layer may include an organic layer containing an organic polymer. That is, the inorganic gas barrier layer may be a laminate containing an inorganic layer and an organic layer.

[0288] Regarding the organic layer, firstly, for example, an organic monomer or organic oligomer is coated onto a resin substrate to form a layer. Then, polymerization and crosslinking as needed are performed, for example, using an electron beam apparatus, a UV light source, a discharge apparatus, or other suitable apparatus, thereby forming the layer.

[0289] Furthermore, regarding the organic layer, for example, organic monomers or organic oligomers that can be flash-evaporated and radiocrosslinked can be vapor-deposited. Then, it can be formed by forming a polymer from the organic monomers or organic oligomers. Coating efficiency can be improved by cooling the resin substrate.

[0290] Coating methods for organic monomers or organic oligomers include, for example, roller coating (e.g., gravure roller coating) and spray coating (e.g., electrostatic spraying). Furthermore, examples of laminates consisting of inorganic and organic layers include those described in International Publication No. 2012 / 003198 and International Publication No. 2011 / 013341.

[0291] In the case of a laminate consisting of inorganic and organic layers, the thickness of each layer can be the same or different.

[0292] The thickness of the inorganic layer is preferably in the range of 3 to 1000 nm, more preferably in the range of 10 to 300 nm. The thickness of the organic layer is preferably in the range of 100 nm to 100 µm, more preferably in the range of 1 to 50 µm.

[0293] Example

[0294] The following examples illustrate the invention in detail, but the invention is not limited to these examples. It should be noted that, unless otherwise specified, the operation is performed at room temperature (25°C) in the following examples. Furthermore, unless otherwise specified, "%" and "parts" refer to "mass %" and "parts by mass," respectively.

[0295] [Preparation of sealing compositions 1-16]

[0296] The monofunctional (meth)acrylates and diacrylates were weighed under a nitrogen atmosphere in the manner shown in Table I below, in the form of the types and parts by mass.

[0297] Furthermore, as photopolymerization initiators, sensitizers, and polymerization inhibitors, the following substances are placed in a brown bottle and stirred on a hot plate at 65°C for 3 hours to obtain sealing compositions 1 to 16.

[0298] <Photopolymerization Initiator>

[0299] BAPO (Diacylphosphine Oxide): IRGACURE (Registered Trademark) 819: 5 parts by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by BASF).

[0300] <Sensitizer>

[0301] 2-ITX: 1 part by weight of 2-isopropylthioxanthone (manufactured by Lambson Company)

[0302] <Polymerization inhibitor>

[0303] IRGASTAB (registered trademark) UV10: [1,10-dioxodecane-1,10-diylbis(oxy)bis(2,2,6,6-tetramethyl-4,1-piperidinidyl)dioxy] radical (manufactured by BASF) 0.1 parts by weight

[0304] [Chemistry 4]

[0305]

[0306] <Monofunctional (meth)acrylates>

[0307] a-1: o-Phenylenoxyethyl acrylate (A-LEN10, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0308] a-2: Nonylphenol EO-modified acrylate (M-111, manufactured by Dong-A Synthetic Co., Ltd.)

[0309] a-3: Phenoxy diethylene glycol acrylate (AMP-20GY, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0310] a-4: Stearyl acrylate (AS, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0311] a-5: Isoborneol acrylate (manufactured by IBA, Kyoei Chemical Co., Ltd.)

[0312] a-6:4-Phenylenylbenzylacrylate (NK Ester A-BPML, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0313] <Diacrylate>

[0314] a-7: Triethylene glycol diacrylate (SR272, manufactured by Arkema)

[0315] a-8: Triethylene glycol dimethacrylate (SR205, manufactured by Arkema)

[0316] a-9: Decyl diacrylate (ADODN, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0317] a-10: Tricyclodecanediethanol diacrylate (A-DCP, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0318] [Table 1]

[0319]

[0320] [Peak loss coefficient (tanδ) and storage modulus (G')]

[0321] The RSA3, manufactured by TA Instruments, was used as the apparatus for measuring dynamic viscoelasticity. A tensile tool was used for sample mounting.

[0322] As a sample, a coating of the sealing composition with a thickness of 10 µm or 20 µm was prepared on a glass substrate with dimensions of 50 mm × 50 mm under a nitrogen atmosphere, as shown in Table II below. For this coating, under a nitrogen atmosphere, at 300 mW / cm²... 2 Under these conditions, the cumulative light intensity is 1.5 J / cm². 2 The coating is cured by irradiating it with ultraviolet light of 395nm wavelength (IST MZ240mm 395nm UVLED). The resulting cured film (sealing film) is then peeled off from the glass substrate.

[0323] It should be noted that for sealing films 7-1 and 7-2, the cumulative light intensity is 1.0 J / cm², respectively. 2 1.8J / cm 2 Irradiation is performed in this manner.

[0324] The sample was cut to a length of 40 mm and a width of 5 mm.

[0325] The conditions for measuring dynamic viscoelasticity were: gap length 20 mm, strain 0.05%, frequency 10 Hz, temperature 0~180℃, and heating rate 5℃ / min.

[0326] (Analysis)

[0327] The energy storage modulus G' is the value measured at 25°C.

[0328] As an indicator of viscosity, the peak value (maximum value) of tanδ (=G” / G': where G” is the loss modulus) is used.

[0329] [Cure Rate]

[0330] Under a nitrogen atmosphere, a coating of sealing composition with a thickness of 10 μm or 20 μm is prepared on a glass substrate having a size of 50 mm × 50 mm, as shown in Table II below.

[0331] For this coating, under a nitrogen atmosphere, at 300 mW / cm 2 Under these conditions, the cumulative light intensity is 1.5 J / cm². 2 The coating is cured by irradiating it with ultraviolet light of 395nm wavelength (IST MZ 240mm 395nm UVLED).

[0332] It should be noted that for sealing films 7-1 and 7-2, the cumulative light intensity is 1.0 J / cm², respectively. 2 1.8J / cm 2 Irradiation is performed in this manner.

[0333] The cured film (sealing film) and the uncured composition were subjected to FTIR (Nexus 870 infrared spectrometer) measurements. The peak (810 cm⁻¹) originating from the C=C bond of the (meth)acryloyl group in the obtained spectrum was determined. -1 The strength of the curing rate is calculated using the following formula.

[0334] Curing rate (%) = (1 - a / b) × 100

[0335] a: Peak value of the sealing composition before curing from C=C bonds

[0336] b: Peak value of the cured sealant from C=C bonds

[0337] [Evaluation of the Sealing Composition]

[0338] <Adhesion>

[0339] A silicon nitride film (SiNx) with a thickness of 500 nm was formed on an alkali-free glass by plasma CVD method (Vickers hardness HV900). Next, from the silicon nitride film, each of the above-prepared sealing compositions was applied by inkjet method after being left standing in a thermostat at 60 °C for one week.

[0340] For the formed coating film, in a nitrogen atmosphere, at 300 mW / cm 2 The ultraviolet light with a wavelength of 395 nm was irradiated in such a way that the cumulative light amount became 1.5 J / cm 2 to cure the coating film. Evaluation samples of sealing films 1 to 16 were thus obtained. It should be noted that for sealing films 7-1 and 7-2, the irradiation was carried out in such a way that the cumulative light amounts became 1.0 J / cm 2 and 1.8 J / cm 2 respectively.

[0341] The ultraviolet light used was MZ (240 mm, 395 nm: UVLED) manufactured by IST Corporation.

[0342] In addition, for the silicon nitride film, the chamber was depressurized, and silane (SiH4), ammonia (NH3), and hydrogen (H2) were heated and supplied into the chamber as raw material gases to form it. In addition, by adjusting the coating times and resolution of the inkjet, the thickness of the sealing film was made as shown in Table II below.

[0343] For evaluation, after making a cut in the sealing film with a knife, a peel test using a tape (600 manufactured by 3M Company) was carried out. In the following evaluation criteria, A, B, and C were considered qualified.

[0344] (Evaluation Criteria)

[0345] A: The adhesion force between the sealing film and the silicon nitride film is 3 N or more

[0346] B: The adhesion force between the sealing film and the silicon nitride film is 2 N or more and less than 3 N

[0347] C: The adhesion force between the sealing film and the silicon nitride film is 1 N or more and less than 2 N

[0348] D: The adhesion force between the sealing film and the silicon nitride film is 0.1 N or more and less than 1 N

[0349] [Fabrication of Organic EL Element 1]

[0350] (1) Preparation of Substrate

[0351] As the film substrate, a 15 μm polyimide film is prepared. Then, on this polyimide film, a gas barrier layer (SiO2 film: 250 nm / SiNx film: 50 nm / SiO2 film: 500 nm (upper layer / middle layer / lower layer)) for the film substrate is formed by plasma CVD.

[0352] (2) Formation of the first electrode

[0353] An Al film was formed on one side of the substrate as a first electrode (metal layer) under the following conditions. The thickness of the formed first electrode was 150 nm. It should be noted that the thickness of the first electrode was measured using a contact surface shape measuring instrument (DECTAK). For the Al film, a vacuum evaporation apparatus was used, with the pressure reduced to a vacuum degree of 1 × 10⁻⁶. -4 After Pa, it is formed using a tungsten resistance heating crucible.

[0354] (3) Formation of organic EL layer

[0355] First, in each deposition crucible within the vacuum deposition apparatus, the materials described below, constituting each layer of the organic functional layer, are filled in an amount optimally suited to the fabrication of each component. The deposition crucibles are made of resistance heating materials such as molybdenum or tungsten.

[0356] (3-1) Formation of the hole injection layer

[0357] Reduced pressure to a vacuum level of 1×10 -4 After Pa, the evaporation crucible containing the following compound A-1 is heated by energizing. Next, a hole injection layer with a thickness of 10 nm is formed on the first electrode (metal layer side) by evaporation at a evaporation rate of 0.1 nm / s.

[0358] (3-2) Formation of the hole transport layer

[0359] Next, the evaporation crucible containing the following compound M-2 is heated by energizing, and a hole injection layer is evaporated on the hole transport layer at a evaporation rate of 0.1 nm / s to form a hole transport layer with a thickness of 30 nm.

[0360] (3-3) Formation of the light-emitting layer

[0361] Next, the following compounds BD-1 and H-1 were co-deposited at a concentration of 7% by mass of BD-1 at a deposition rate of 0.1 nm / s to form a 15 nm thick light-emitting layer (fluorescent layer) that exhibits blue light emission.

[0362] Next, the following compounds GD-1, RD-1, and H-2 were co-deposited at a concentration of 20% by mass for GD-1 and 0.5% by mass for RD-1 at a deposition rate of 0.1 nm / s. Then, a yellow phosphorescent layer (phosphorescent layer) with a thickness of 15 nm was formed.

[0363] (3-4) Formation of the electron transport layer

[0364] Then, as an electron transport material, an electric current is applied to a heating boat containing the following compound T-1 to form an electron transport layer composed of Alq3 (tris(8-hydroxyquinoline)) on the light-emitting layer. At this time, the evaporation rate is set to a range of 0.1~0.2 nm / s, and the thickness is set to 30 nm.

[0365] (3-5) Formation of the electron injection layer (metal affinity layer)

[0366] Secondly, as an electron injection material, a heating boat containing compound I-1 is heated by passing an electric current through it, forming an electron injection layer composed of Liq on the electron transport layer. At this time, the evaporation rate is set to a range of 0.01~0.02 nm / s, and the thickness is set to 2 nm. It should be noted that this electron injection layer functions as a metal affinity layer.

[0367] Through the above process, an organic EL layer that emits white light is formed.

[0368] (4) Formation of the second electrode

[0369] Then, a Mg / Ag mixture (Mg:Ag=1:9 (volume ratio)) is vapor-deposited with a thickness of 10nm to form a second electrode and its extraction electrode.

[0370] (5) Formation of the capping layer

[0371] Then, it is transferred to the original vacuum chamber. On the electrode, α-NPD (4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl) is deposited at a deposition rate of 0.1~0.2 nm / s to a thickness of 40 nm. Then, a capping layer is formed to improve light extraction.

[0372] (6) Formation of the first sealing layer

[0373] Secondly, as the first sealing layer covering the light-emitting part of the organic EL element, a silicon nitride (SiNx) with a thickness of 500 nm and a Vickers hardness of HV900 is formed using plasma CVD.

[0374] (7) Formation of the second sealing layer

[0375] Next, the prepared sealing composition 1 is left to stand in a constant temperature bath at 60°C for one week, and then filled into the inkjet printhead of the inkjet device under a nitrogen atmosphere. Then, for the organic EL element to which the first sealing layer is formed, the time-varying sealing composition 1 is coated using an inkjet method under a nitrogen atmosphere. Afterwards, the formed coating film is subjected to a nitrogen atmosphere at 300 mW / cm². 2 Under these conditions, the cumulative light intensity is 1.5 J / cm². 2 The coating is cured by irradiating it with ultraviolet light of 395nm wavelength (IST MZ 240mm 395nm UVLED) to form a second sealing layer.

[0376] By adjusting the number of inkjet coatings and the resolution, the thickness of the second sealing layer is set as shown in Table II below.

[0377] (8) Formation of the third sealing layer

[0378] Secondly, on the second sealing layer, as the third sealing layer, a silicon nitride (SiNx) with a thickness of 500 nm and a Vickers hardness of HV900 is formed by plasma CVD, to obtain an organic EL element 1 for evaluation with the first to third sealing layers formed thereon.

[0379] [Fabrication of Organic EL Components 2~16]

[0380] Except for changing the sealing composition 1 used in the formation of the second sealing layer as shown in the table below during the fabrication of the organic EL element 1, the organic EL elements 2 to 16 for evaluation are fabricated in the same manner.

[0381] It should be noted that, except for the sealing composition 1 and film thickness as shown in Table II below, the organic EL elements 7-1 and 7-2 have their cumulative light intensity set to 1.0 J / cm. 2 1.8J / cm 2 Apart from changing the method, it is made in the same way.

[0382] [Evaluation of Organic EL Devices]

[0383] <Bending resistance>

[0384] Each organic EL element was wound around a 10mm diameter metal roller and subjected to accelerated degradation testing in a constant temperature and humidity bath (60°C, 90% relative humidity). During this process, the polyimide film serving as the substrate was wound in contact with the metal roller. After 1500 hours, each organic EL element was removed from the bath and examined under a microscope at room temperature to confirm its luminescence state (dark spot area ratio). Evaluation criteria A, B, and C below were considered acceptable.

[0385] (Evaluation Criteria)

[0386] A: The dark spot area ratio is less than 0.1%.

[0387] B: The dark spot area ratio is above 0.1% but less than 0.5%.

[0388] C: Dark spot area ratio is above 0.5% but less than 1%.

[0389] D: The dark spot area ratio is above 1%.

[0390] <Heat resistance>

[0391] Each organic EL element was wound around a 10mm diameter metal roller and placed in a constant temperature and humidity bath at 100°C for accelerated degradation testing. During this process, the polyimide film serving as the substrate was wound in contact with the metal roller. After 1500 hours, each organic EL element was removed from the bath and examined under a microscope at room temperature to confirm its luminescence state (dark spot area ratio). Evaluation criteria A, B, and C below were considered acceptable.

[0392] (Evaluation Criteria)

[0393] A: The dark spot area ratio is less than 0.1%.

[0394] B: The dark spot area ratio is above 0.1% but less than 0.5%.

[0395] C: Dark spot area ratio is above 0.5% but less than 1%.

[0396] D: The dark spot area ratio is above 1%.

[0397] [Table 2]

[0398]

[0399] As the results described above show, it can be confirmed that the sealing composition of the present invention is superior to the sealing composition of the comparative example in terms of sealing performance, bending resistance and heat resistance.

[0400] The present invention can be used for sealing compositions for inkjet electronic devices, methods for forming sealing films for electronic devices, and sealing films for electronic devices.

Claims

1. A sealing composition for inkjet electronic devices, comprising a photopolymerizable monomer and a photopolymerization initiator, wherein, As the photopolymerizable monomer, it contains (meth)acrylate. Regarding the dynamic viscoelasticity of the cured composition for sealing electronic devices... The peak value of the loss coefficient (tanδ) is in the range of 0.3 to 1.0, and The energy storage modulus (G') is in the range of 1.0~3.0 GPa.

2. The sealing composition for electronic devices used in inkjet printing according to claim 1, wherein, As the (meth)acrylate, it contains a monofunctional (meth)acrylate. The content of the monofunctional (meth)acrylate relative to the total amount of the photopolymerizable monomer is 41% by mass or more.

3. The sealing composition for inkjet electronic devices according to claim 1, wherein, The (meth)acrylate has a phenyl group.

4. The sealing composition for electronic devices for inkjet printing according to claim 1, wherein, Irradiation at 1.5~1.8 J / cm under a nitrogen atmosphere 2 When cured by ultraviolet light with a wavelength of 395nm, the curing rate of the resulting electronic device sealing film is over 80%.

5. A method for forming a sealing film for an electronic device, comprising using the sealing composition for electronic devices according to any one of claims 1 to 4 to form a sealing film, comprising: The process of forming the first sealing layer on electronic devices using a vapor phase method; and The process of forming a second sealing layer by coating the electronic device sealing composition onto the first sealing layer.

6. The method for forming an electronic device sealing film according to claim 5, comprising the step of forming a third sealing layer on the second sealing layer by a vapor phase method.

7. The method for forming a sealing film for electronic devices according to claim 5, wherein, The process of forming the second sealing layer uses inkjet printing.

8. An electronic device sealing film, which is used to seal electronic devices, and has the following characteristics: A first sealing layer containing silicon nitride, silicon oxide, or silicon oxynitride; and The second sealing layer obtained using the electronic device sealing composition according to any one of claims 1 to 4.

9. The electronic device sealing film according to claim 8, wherein a third sealing layer containing silicon nitride, silicon oxide or silicon oxynitride is present on the second sealing layer.

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