TWI867642B - Composition for sealing electronic device, electronic device sealing film, and method for forming electronic device sealing film - Google Patents

Abstract

[Topic] Provide an electronic device sealing composition, an electronic device sealing film and a method for forming the same, which have excellent discharge stability, luminescence characteristics and crack resistance and can form a low dielectric sealing film. [Solution] The sealing composition contains (meth)acrylate as a photopolymerizable monomer, and S1 calculated from the dipole moment μ[Debye] and molecular volume V[cm ³・mol ^-1 ] and hydrogen bonding term δH[MPa ^1/2 ] of the photopolymerizable monomer is in the range of 0.10×10 ^-2 ～1.10×10 ^-2 [Debye/(cm ³・mol ^-1 )], or S2 is in the range of 0.50×10 ^-2 ～1.50×10 ^-2 [MPa ^1/2 /(cm ³・mol ^-1 )]. (m is the molar ratio of the monomer, and the suffixes of m, μ, V and δH are the numbers of the monomers).

Description

Composition for sealing electronic device, electronic device sealing film, and method for forming electronic device sealing film

The present invention relates to an electronic device sealing composition, an electronic device sealing film and a method for forming the electronic device sealing film, and more particularly to an electronic device sealing composition which has excellent ejection stability, luminescence characteristics and crack resistance by an inkjet method and can form an electronic device sealing film with a relatively low dielectric constant.

Ink compositions for organic EL thin films required for thin film formation of light-emitting layers of electronic devices, especially organic electroluminescent devices (hereinafter also referred to as "organic EL devices" or "organic EL elements"), have been proposed previously. For example, Patent Document 1 discloses a high-viscosity organic EL ink composition that can be produced by an inexpensive printing technology other than the inkjet method, which contains: an organic EL material, a liquid crystal compound with an energy band gap of 3.5 ev or more, and a solvent composed of organic compounds. It is also disclosed that the molecular dipole moment of the aforementioned liquid crystal compound is preferably less than 4.0 Debye. Then, by having a high viscosity and maintaining high-efficiency and long-life luminescence characteristics, it can be widely applied to various coating methods.

Furthermore, Patent Document 2 discloses that the resin composition used in the field of electrical machinery is a hardening resin composition containing ethylene polymer powder formed by ethylene polymer having a glass transition temperature of 120°C or higher and a mass average molecular weight of 100,000 or higher. In particular, it is disclosed that the molar volume of the monomer unit of the ethylene monomer is preferably 150 ^cm3 /mol or higher. Then, by such a technology, it is possible to provide a hardening resin composition with good dispersibility, and the hardening resin composition can be quickly turned into a colloidal state by heating for a short time, and the linear expansion coefficient can be reduced, and a hardened material with good crack resistance can be provided.

On the other hand, in order to prevent the organic materials or electrodes used in electronic devices from deteriorating due to moisture, it has been proposed to cover the surface of the organic EL element with a sealing layer. However, such a sealing layer is required to have excellent luminescent properties without affecting the luminescent layer of the organic EL element, and to be a sealing composition with excellent crack resistance after curing. In addition, when forming it by inkjet method, it is required that the sealing composition be stably ejected from the nozzle. Even when polarization is difficult when an electric field is applied to the electronic device, it is also desired to have a low relative dielectric constant. [Prior art literature] [Patent literature]

[Patent Document 1] International Publication No. 2010/143431 [Patent Document 2] International Publication No. 2013/062123

[The problem that the invention wants to solve]

The present invention is developed in view of the above-mentioned problems and conditions, and the problem to be solved is to provide an electronic device sealing composition that has excellent ejection stability, luminescence characteristics and crack resistance due to the inkjet method, and can form an electronic device sealing film with a relatively low dielectric constant. In addition, an electronic device sealing film using the electronic device sealing composition and a method for forming an electronic device sealing film are provided. [Means for solving the problem]

In order to solve the above-mentioned problems, the inventors of the present invention have conducted research on the causes of the above-mentioned problems and found that when the photopolymerizable monomer contains (meth)acrylate, the dipole moment (μ), SP value (hydrogen bonding term δH) and molecular volume (V) of the photopolymerizable monomer meet specific conditions, the ejection stability, luminescence characteristics and crack resistance caused by the inkjet method can be excellent, and a low-dielectric electronic device sealing film can be formed, thereby completing the present invention. That is, the above-mentioned problems described in the present invention are solved by the following means.

1. An electronic device sealing composition comprising a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer comprises (meth)acrylate; the following S1 calculated from the dipole moment μ[Debye], molecular volume V[cm ³ ･mol ^-1 ] and hydrogen bonding term δH[MPa ^1/2 ] of the photopolymerizable monomer is in the range of 0.10×10 ^-2 to 1.10×10 ^-2 [Debye/(cm ³ ･mol ^-1 )], or the following S2 is in the range of 0.50×10 ^-2 to 1.50×10 ^-2 [MPa ^1/2 /(cm ³ ･mol ^-1 )]: (In the above formula, m is the molar ratio of the monomer, and the suffixes of m, μ, V and δH are the numbers of the monomers).

2. The electronic device sealing composition as described in item 1, wherein the S1 is in the range of 0.50×10 ^-2 to 0.80×10 ^-2 [Debye/(cm ³ ･mol ^-1 )], or the S2 is in the range of 0.50×10 ^-2 to 1.00×10 ^-2 [MPa ^1/2 /(cm ³ ･mol ^-1 )].

3. The electronic device sealing composition as described in item 1, wherein the hydrogen bonding term δH is in the range of 1.9 to 3.5 MPa ^1/2 .

4. An electronic device sealing film is an electronic device sealing film for sealing an electronic device, characterized by having: A first sealing layer containing: silicon nitride, silicon oxide or silicon oxynitride; and A second sealing layer using an electronic device sealing composition as described in any one of items 1 to 3.

5. The electronic device sealing film as described in item 4, wherein a third sealing layer is provided on the second sealing layer, and the third sealing layer contains silicon nitride, silicon oxide or silicon nitride oxide.

6. A method for forming an electronic device sealing film, which is a method for forming an electronic device sealing film using an electronic device sealing composition as described in any one of items 1 to 3, characterized by comprising: a process of forming a first sealing layer on an electronic device by a vapor phase method; and a process of forming a second sealing layer by applying the electronic device sealing composition on the first sealing layer.

7. The method for forming a sealing film for an electronic device as recited in item 6, comprising: forming a third sealing layer on the second sealing layer by a vapor phase method.

8. The method for forming a sealing film for an electronic device as described in item 6, wherein the second sealing layer is formed by an inkjet method. [Effect of the invention]

By means of the above-mentioned means of the present invention, an electronic device sealing composition is provided, which has excellent ejection stability, luminescence characteristics and crack resistance due to the inkjet method, and can form an electronic device sealing film with a relatively low dielectric constant. In addition, an electronic device sealing film and a method for forming an electronic device sealing film using the electronic device sealing composition are provided. The presentation mechanism or action mechanism of the effect of the present invention is not yet clear, but it is inferred as follows.

In the present invention, the aforementioned S1 calculated based on the dipole moment μ[Debye] and the molecular volume V[cm ³ ･mol ^-1 ] of the aforementioned photopolymerizable monomer is the dipole moment per unit volume of the molecule, and is a value indicating the dipole moment normalized to the size of the molecule; the aforementioned S2 calculated based on the hydrogen bonding term δH[MPa ^1/2 ] and the molecular volume V[cm ³ ･mol ^-1 ] is δH per unit volume of the molecule, and is a value indicating the hydrogen bonding term component δH of the SP value normalized to the size of the molecule.

(Discharge stability) The inkjet head ejects tiny droplets. Therefore, the surface area per mass unit of the liquid is larger. If a highly volatile material, such as an organic solvent, is used, it will volatilize near the nozzle of the inkjet head, causing the viscosity to increase. In contrast, in the present invention, the photopolymerizable monomer contains (meth) acrylate, which is an acrylic monomer. Therefore, the acrylic material has low volatility and can stably discharge the sealing composition of the present invention from the nozzle. Furthermore, by making the aforementioned S1 or the aforementioned S2 fall within the aforementioned specific range, the polarity will become an appropriate range, the interaction between the monomers in the sealing composition will become stronger, and the volatility can be made lower. It is speculated that this also makes the discharge stability excellent.

(Luminescence properties) Generally, when an electronic device (e.g., an organic EL element) is stored at a high temperature (e.g., 85°C), the components of the sealing layer will diffuse. If the diffusion is too fast, it will reach the sealed organic EL element. However, even if the components of the sealing layer reach the organic EL element, it will not cause a problem as long as it does not affect the organic layer or electrode of the organic EL element. Therefore, it is inferred that whether it is easy to diffuse and whether it will affect the organic layer or electrode is related to the molecular size and polarity of the components of the sealing layer (i.e., the sealing composition). Therefore, it is inferred that by making the aforementioned S1 or the aforementioned S2 fall within the aforementioned specific range, an electronic device with excellent luminescence properties can be obtained.

(Crack resistance (appearance when stored in a low-temperature environment while being bent)) In a low-temperature environment, the sealing layer formed by the sealing composition will shrink due to heat. If it is stored in a low-temperature environment in a bent state, further heat shrinkage will apply stress to the sealing layer, causing peeling and cracking. Here, heat shrinkage is considered to be affected by the structure in which the molecules in the sealing layer are filled and how the molecules interact with each other. Therefore, it is speculated that by making the aforementioned S1 or the aforementioned S2 fall within the aforementioned specific range, the molecular size and polarity of the components of the sealing layer (i.e., the sealing composition) will fall within the appropriate range, which can reduce the influence of thermal shrinkage, and the appearance state (crack resistance) when the bend is maintained and stored in a low temperature environment will become good.

(Low dielectric) Organic EL elements are preferably difficult to polarize when an electric field is applied. Whether or not they are polarized is believed to depend on the directionality and ease of movement of the molecules of the components of the sealing film after the sealing composition is cured. Therefore, the less the molecules can move, the better. Therefore, it is speculated that by making the aforementioned S1 or the aforementioned S2 fall within the aforementioned specific range, the ratio of the molecular size and polarity of the components of the sealing composition will be set within an appropriate range, which can maximize the interaction between molecules, making it difficult for the molecules to move, and becoming low dielectric (relative dielectric constant becomes lower).

The electronic device sealing composition of the present invention is an electronic device sealing composition containing a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer contains (meth)acrylate; the following S1 calculated from the dipole moment μ[Debye], molecular volume V[cm ³ ･mol ^-1 ] and hydrogen bonding term δH[MPa ^1/2 ] of the photopolymerizable monomer is in the range of 0.10×10 ^-2 to 1.10×10 ^-2 [Debye/(cm ³ ･mol ^-1 )], or the following S2 is in the range of 0.50×10 ^-2 to 1.50×10 ^-2 [MPa ^1/2 /(cm ³ ･mol ^-1 )]: (In the above formula, m is the molar ratio of the monomer, and the suffixes of m, μ, V and δH are the numbers of the monomers.) This feature is a feature of the technology common to or corresponding to each of the following embodiments.

In an embodiment of the present invention, S1 is in the range of 0.50×10 ^-2 to 0.80×10 ^-2 [Debye/(cm ³ mol ^-1 )], or S2 is in the range of 0.50×10 ^-2 to 1.00×10 ^-2 [MPa ^1/2 /(cm ³ mol ^-1 )], which is preferred from the viewpoint of excellent ejection stability, luminescence characteristics and crack resistance by inkjet method, and the formation of an electronic device sealing film with a relatively low dielectric constant. In addition, the hydrogen bond term δH is in the range of 1.9 to 3.5 MPa ^1/2 , which is preferred from the viewpoint of crack resistance.

The electronic device sealing film of the present invention is an electronic device sealing film for sealing an electronic device, and is characterized by having: a first sealing layer containing: silicon nitride, silicon oxide or silicon oxynitride; and a second sealing layer using the aforementioned electronic device sealing composition. Thereby, it is possible to achieve excellent ejection stability, luminescence characteristics and crack resistance due to the inkjet method, and to form an electronic device sealing film with a relatively low dielectric constant.

It is preferred that the third sealing layer is provided on the second sealing layer and contains silicon nitride, silicon oxide or silicon oxynitride, in view of excellent sealing performance.

The electronic device sealing film forming method of the present invention is a method for forming an electronic device sealing film using the aforementioned electronic device sealing composition, and is characterized by comprising: a process of forming a first sealing layer on an electronic device by a vapor phase method; and a process of forming a second sealing layer by applying the aforementioned electronic device sealing composition on the aforementioned first sealing layer. Thereby, the ejection stability, luminescence characteristics and crack resistance caused by the inkjet method can be achieved, and an electronic device sealing film with a low relative dielectric constant can be formed.

The process of forming the third sealing layer on the second sealing layer by a vapor phase method is preferred from the viewpoint of excellent sealing performance. Also, the second sealing layer is formed by an inkjet method, which is preferred from the viewpoint of being able to form the layer with high precision.

The present invention and its constituent elements and the forms and aspects required for implementing the present invention are described below. In addition, in the present case, the numerical values recorded before and after "～" are used as the meaning of being inclusive of the lower limit and the upper limit.

[Overview of the inkjet electronic device sealing composition of the present invention] The inkjet electronic device sealing composition of the present invention (hereinafter also referred to as "sealing composition") is an electronic device sealing composition containing a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer contains (meth)acrylate, and the following S1 calculated based on the dipole moment μ[Debye], molecular volume V[cm ³ ･mol ^-1 ] and hydrogen bonding term δH[MPa ^1/2 ] of the photopolymerizable monomer is in the range of 0.10×10 ^-2 to 1.10×10 ^-2 [Debye/(cm ³ ･mol ^-1 )], or the following S2 is in the range of 0.50×10 ^-2 to 1.50×10 ^-2 [MPa ^1/2 /(cm ³ ･mol ^-1 )]: (In the above formula, m is the molar ratio of the monomer, and the suffixes of m, μ, V and δH are the numbers of the monomers).

<Dipole moment (μ)> The aforementioned dipole moment (μ) can be calculated by using chemical structure information computer software. As calculation software, for example, the "Gaussian series" of quantitative chemical calculation programs manufactured by HULINKS can be cited. The dipole moment in the present invention is obtained based on the information of the chemical structure using Gaussian software manufactured by HULINKS to obtain the dipole moment (unit: Debye) of each monomer. In the calculation, PM6, a semi-empirical method, is used.

The dipole moment (μ) of each photopolymerizable monomer is not particularly limited as long as S1 is in the range of 0.10×10 ^-2 to 1.10×10 ^-2 [Debye/(cm ³ mol ^-1 )], but is preferably in the range of 0.5 to 1.7 Debye from the viewpoint of compatibility of the photopolymerizable monomers and solubility of the photopolymerization initiator.

<Molecular volume (V)> The aforementioned molecular volume (V) indicates the molecular volume per unit mole. Molar volume can be calculated using computer software based on chemical structure information. The molecular volume (V) in the present invention is obtained based on chemical structure information using Hansen Solubility Parameters in Practice (HSPiP) software to obtain the molecular volume (V) of each monomer (unit: cm ³ ･mol ^-1 ).

The molecular volume (V) of each photopolymerizable monomer is not particularly limited as long as S1 is in the range of 0.10×10 ^-2 ～1.10×10 ^-2 [Debye/(cm ³ ･mol ^-1 )] or S2 is in the range of 0.50×10 ^-2 ～1.50×10 ^-2 [MPa ^1/2 /(cm ³ ･mol ^-1 )], but is preferably in the range of 150～600 (cm ³ ･mol ^-1 ) in order to adjust the viscosity of the photopolymerizable monomer.

<Hydrogen bonding term (δH)> The aforementioned hydrogen bonding term (δH) is the hydrogen bonding term component of the Hansen solubility parameter. The Hansen solubility parameter is obtained by considering the Hildebrand solubility parameter as being caused by three kinds of interactions, namely dispersion force, dipole-dipole force, and hydrogen bonding force, and dividing it into three components, namely, dispersion term component δD, polar term component δP, and hydrogen bonding term component δH. δH can be calculated using computer software based on chemical structure information. The hydrogen bonding term (δH) in the present invention is the hydrogen bonding term (δH) (unit: MPa ^1/2 ) of each monomer obtained using the software Hansen Solubility Parameters in Practice (HSPiP) based on chemical structure information.

The hydrogen bonding term δH of each photopolymerizable monomer is preferably in the range of 1.9 to 3.5 MPa ^1/2 .

The molar ratio m of the monomers mentioned above refers to the molar ratio of each monomer when the total molar number of all monomers is regarded as 1.

In order to make S1 calculated from the dipole moment (μ) and molecular volume (V) of the photopolymerizable monomer fall within the range of 0.10×10 ^-2 ～1.10×10 ^-2 [Debye/(cm ³ ･mol ^-1 )], a photopolymerizable monomer with a structure having a lower dipole moment and a larger molecular volume can be used. Examples of structures having a lower dipole moment include structures having fewer hydroxyl groups, structures having fewer impurity atoms, structures having fewer ester groups, structures having alicyclic hydrocarbons, and structures having a higher symmetry in which the dipole moments cancel each other out. Examples of structures with a relatively large molecular volume include alicyclic structures, structures with a relatively large molecular weight, and structures with an alkylene group having a carbon chain of 8 or more.

Furthermore, in order to make S2 calculated from the molecular volume (V) and hydrogen bonding term (δH) of the photopolymerizable monomer fall within the range of 0.50×10 ^-2 ~1.50×10 ^-2 [MPa ^1/2 /(cm ³ ･mol ^-1 )], for example, a photopolymerizable monomer having a structure with low hydrogen bonding and a large molecular volume can be used. Examples of the structure with low hydrogen bonding include a structure with fewer hydroxyl groups, a structure with fewer impurity atoms, a structure with fewer ester groups, a methacrylate structure, an alicyclic hydrocarbon structure, and a fluorine-containing structure. Examples of structures with a relatively large molecular volume include alicyclic structures, structures with a relatively large molecular weight, and structures with an alkylene group having a carbon chain of 8 or more.

[Composition of electronic device sealing composition] The electronic device sealing composition of the present invention contains a photopolymerizable monomer and a photopolymerization initiator. The photopolymerizable monomer contains (meth)acrylate.

In this specification, "(meth)acrylate" means at least one of acrylate and methacrylate. In addition, the "electronic device" in the present invention refers to a component that uses the kinetic energy, potential energy, etc. of electrons to generate, amplify, convert, or control electrical signals. For example, active components such as light-emitting diode components, organic electroluminescent components, photoelectric conversion components, and transistors. In addition, in the present invention, passive components such as resistors and capacitors that perform passive work such as "impedance" and "storage" for actions from others are also included in electronic devices. Therefore, the sealing composition of the present invention is used to form the aforementioned sealing film required to seal the electronic device.

<Photopolymerizable monomer> The so-called "photopolymerizable monomer" means a photopolymerizable monomer (also called "photocurable monomer") that absorbs light by itself or a photopolymerization initiator and can undergo a polymerization (hardening) reaction by generating active ions or free radicals. As the aforementioned photopolymerizable monomer, a non-silicon monomer that does not contain silicon (Si) can also be used, for example, a monomer composed of only elements selected from C, H, O, N or S, but it is not limited thereto. The photopolymerizable monomer can be synthesized and used by a conventional synthesis method, or it can be purchased and used as a commercially available product. As the aforementioned photopolymerizable monomer, there can be cited the following photopolymerizable monomer (A) without an aromatic hydrocarbon group, or the photopolymerizable monomer (B) with an aromatic hydrocarbon group, etc., and appropriate selection can be made from these photopolymerizable monomers (A) and (B) so that S1 or S2 satisfies the aforementioned range.

<Photopolymerizable monomer (A) without aromatic hydrocarbon group> The aforementioned photopolymerizable monomer (A) without aromatic hydrocarbon group (hereinafter also referred to as "photopolymerizable monomer (A)") does not contain aromatic hydrocarbon group, and as a photocurable functional group (photopolymerizable functional group), it is a monomer containing one or more of vinyl, acrylic and methacrylic groups up to 1 to 20, specifically, 1 to 6 monomers, for example, 1 to 3, 1 to 2, 1, or 2.

In the present invention, the weight average molecular weight of the photopolymerizable monomer (A) may be in the range of 100 to 500 g/mol, 130 to 400 g/mol, or 200 to 300 g/mol. By setting the weight average molecular weight of the monomer in the range, a more favorable effect can be achieved for the process.

The photopolymerizable monomer (A) may contain a monofunctional monomer, a polyfunctional monomer, or a mixture thereof having a photocurable functional group.

Specifically, the photopolymerizable monomer (A) may be a (meth)acrylate monomer, an unsaturated carboxylic acid ester having an alkyl group with 1 to 20 carbon atoms, a cycloalkyl group with 3 to 20 carbon atoms, a hydroxyl group, and an alkyl group with 1 to 20 carbon atoms; an unsaturated carboxylic acid ester having an aminoalkyl group with 1 to 20 carbon atoms; a vinyl ester of a saturated or unsaturated carboxylic acid with 1 to 20 carbon atoms; a vinyl cyanide compound; an unsaturated amide compound; a monofunctional or polyfunctional (meth)acrylate of a monohydric alcohol or polyhydric alcohol, etc. The aforementioned "polyol" is an alcohol having two or more hydroxyl groups, which may mean an alcohol having 2 to 20, preferably 2 to 10, and more preferably 2 to 6 hydroxyl groups.

In one example, among the photopolymerizable monomers (A), the (meth)acrylate monomer having no aromatic hydrocarbon group may be a mono(meth)acrylate, a di(meth)acrylate, a tri(meth)acrylate, a tetra(meth)acrylate, or the like having a substituted or unsubstituted C1-C20 (carbon number 1-20) alkyl group, a substituted or unsubstituted C1-C20 silyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C1-C20 alkylene group, an amino group, an ethylene oxide group, or the like.

Specifically, the (meth)acrylate monomers without aromatic hydrocarbons may include: unsaturated carboxylates containing (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, cyclohexyl (meth)acrylate, etc.; unsaturated carboxyl aminoalkyl esters such as 2-aminoethyl (meth)acrylate and 2-dimethylaminoethyl (meth)acrylate; saturated or unsaturated carboxyl vinyl esters such as vinyl acetate; vinyl cyanide compounds such as (meth)acrylonitrile; and unsaturated amide compounds such as (meth)acrylamide. Ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, octanediol di(meth)acrylate, nonanediol di(meth)acrylate, decanediol di(meth)acrylate, undecanediol di(meth)acrylate, dodecanediol (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, or a mixture thereof, but is not limited thereto.

In one example of the present invention, the photopolymerizable monomer (A) is a non-aromatic system without an aromatic group, and may also include: a mono(meth)acrylate having an alkyl group with a carbon number of 1 to 20, a mono(meth)acrylate having an amino group, a di(meth)acrylate having a substituted or unsubstituted alkylene group with a carbon number of 1 to 20, a di(meth)acrylate having an oxirane group, a tri(meth)acrylate having an oxirane group, a mono(meth)acrylate having a cyclic carbonized alkyl group, and at least one of di(meth)acrylates.

The mono(meth)acrylate having a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms may specifically be decyl(meth)acrylate, undecyl(meth)acrylate, lauryl(meth)acrylate, tridecyl(meth)acrylate, tetradecyl(meth)acrylate, pentadecyl(meth)acrylate, hexadecyl(meth)acrylate, heptadecyl(meth)acrylate, octadecyl(meth)acrylate, nonadecyl(meth)acrylate, eicosyl(meth)acrylate, or a mixture thereof, but is not limited thereto.

The mono(meth)acrylate having an amino group may be 2-aminoethyl(meth)acrylate, 2-dimethylaminoethyl(meth)acrylate, or a mixture thereof, but is not limited thereto.

The di(meth)acrylate having a substituted or unsubstituted alkylene group with 1 to 20 carbon atoms may be, for example, a di(meth)acrylate having an alkylene group with 1 to 20 carbon atoms, or a non-silicon di(meth)acrylate containing a substituted or unsubstituted long-chain alkylene group. The di(meth)acrylate having a substituted or unsubstituted alkylene group with 1 to 20 carbon atoms may be, for example, octanediol di(meth)acrylate, nonanediol di(meth)acrylate, decanediol di(meth)acrylate, undecanediol di(meth)acrylate, dodecanediol (meth)acrylate, or a mixture thereof, but is not limited thereto. In the case of containing the aforementioned (meth)acrylate having a substituted or unsubstituted alkylene group with 1 to 20 carbon atoms, the light curing rate of the sealing composition of the present invention will be further improved, and the viscosity can be reduced.

The di(meth)acrylate or tri(meth)acrylate having an ethylene oxide group may be, specifically, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, or a mixture thereof, but is not limited thereto.

The mono(meth)acrylate and di(meth)acrylate having a cyclic carbonized alkyl group may be specifically isoborneol (meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenylethoxy (meth)acrylate, or dicyclopentenyl (meth)acrylate, but is not limited thereto.

The photopolymerizable monomer (A) is preferably contained in an amount of 55 to 95% by mass, more preferably 60 to 90% by mass, relative to the total mass of the photopolymerizable monomers (photopolymerizable monomer (A) and photopolymerizable monomer (B)). By setting the amount within the above range, the viscosity of the sealing composition of the present invention will be suitable for forming a sealing film for electronic devices.

<Photopolymerizable monomer (B) having an aromatic hydrocarbon group> The aforementioned photopolymerizable monomer (B) having an aromatic hydrocarbon group (hereinafter also referred to as "photopolymerizable monomer (B)") contains two or more phenyl groups and heteroatoms having a structure represented by the following general formula (1), and the aforementioned photopolymerizable monomer (B) contains at least mono(meth)acrylate or di(meth)acrylate.

[In the above general formula (1), P represents a substituted or unsubstituted alkyl group containing two or more phenyl groups, or a heteroatom-containing alkyl group containing two or more substituted or unsubstituted phenyl groups. ^Z1 and ^Z2 each independently have a structure represented by the following general formula (2). a and b are each an integer from 0 to 2, and a+b is an integer from 1 to 4.]

[In the above general formula (2), * is a linking part to the carbon of P. X represents a single bond, O or S. Y represents a substituted or unsubstituted linear alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms. ^R1 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. c is an integer of 0 or 1.]

In the above general formula (1), P represents a alkyl group containing two or more substituted or unsubstituted phenyl groups, or a alkyl group containing a heteroatom containing two or more substituted or unsubstituted phenyl groups. The above alkyl group containing two or more substituted or unsubstituted phenyl groups, or a heteroatom-containing alkyl group containing two or more substituted or unsubstituted phenyl groups means that the two or more substituted or unsubstituted phenyl groups are not condensed but are linked via a single bond, an oxygen atom, a sulfur atom, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, an alkylene group having 3 to 6 carbon atoms substituted or unsubstituted with a heteroatom, an ethenylene group, an ethynylene group, or a carbonyl group.

For example, the aforementioned alkyl group containing two or more phenyl groups or the heteroatom-containing alkyl group containing two or more phenyl groups may also include: substituted or unsubstituted biphenyl group, substituted or unsubstituted triphenylmethyl group, substituted or unsubstituted terphenyl group, substituted or unsubstituted extended biphenyl group, substituted or unsubstituted extended triphenyl group, substituted or unsubstituted extended tetraphenyl group, substituted or unsubstituted 2-phenyl-2-(phenylthio)ethyl group, substituted or unsubstituted 2,2-diphenylpropyl group, substituted or unsubstituted diphenylmethyl group, substituted or unsubstituted isopropylphenyl group, substituted or unsubstituted bisphenol F group, substituted or unsubstituted bisphenol A group, substituted or unsubstituted biphenyloxy group, substituted or unsubstituted terphenyloxy group, substituted or unsubstituted tetraphenyloxy group, substituted or unsubstituted pentphenyloxy group, and structural isomers thereof, but are not limited thereto.

The aforementioned monomer having two or more substituted or unsubstituted phenyl groups may be a mono(meth)acrylate, a di(meth)acrylate, or a mixture thereof, and examples thereof include: 4-(meth)acryloyloxy-2-hydroxybenzophenone, ethyl-3,3-diphenyl(meth)acrylate, benzoyloxyphenyl(meth)acrylate, bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, bisphenol F di(meth)acrylate, ethoxylated bisphenol F di(meth)acrylate, (Meth)acrylate, 4-isopropylphenylphenoxyethyl acrylate, ethoxylated bisphenylfluorene diacrylate, 2-phenylphenoxyethyl (meth)acrylate, 2,2'-phenylphenoxyethyl di(meth)acrylate, 2-phenylphenoxypropyl (meth)acrylate, 2,2'-phenylphenoxypropyl di(meth)acrylate, 2-phenylphenoxybutyl (meth)acrylate, 2,2'-phenylphenoxybutyl di(meth)acrylate, 2-(3-phenylphenyl)ethyl (meth)acrylate, 2-(4-benzylphenyl)ethyl (meth)acrylate, 2-phenyl-2-(phenylthio)ethyl (meth)acrylate, 2-(triphenylmethyloxy)ethyl (meth)acrylate, 4-(triphenylmethyloxy)butyl (meth)acrylate, 3-(biphenyl-2-yloxy)butyl (meth)acrylate, 2-(biphenyl-2-yloxy)butyl (meth)acrylate, 4-(biphenyl-2-yloxy)propyl (meth)acrylate, 3-(biphenyl-2-yloxy)butyl (meth)acrylate -2-yloxy)propyl (meth)acrylate, 2-(biphenyl-2-yloxy)propyl (meth)acrylate, 4-(biphenyl-2-yloxy)ethyl (meth)acrylate, 3-(biphenyl-2-yloxy)ethyl (meth)acrylate, 2-(4-benzylphenyl)ethyl (meth)acrylate, 4,4'-bis(acryloyloxymethyl)biphenyl, 2,2'-bis(2-acryloyloxyethoxy)biphenyl, structural isomers thereof or mixtures thereof, but are not limited thereto. In addition, the (meth)acrylate mentioned in the present invention is only an example and is not limited thereto. In fact, the present invention also includes all acrylates in a structural isomer relationship. For example, as an example of the present invention, even if only 2,2'-phenylphenoxyethyl di(meth)acrylate is mentioned, the present invention still includes 3,2'-phenylphenoxyethyl di(meth)acrylate, 3,3'-phenylphenoxyethyl di(meth)acrylate, etc., which are equivalent to all its structural isomers.

In one embodiment of the present invention, the monomer having two or more phenyl groups may be a mono(meth)acrylate represented by the following general formula (4).

In the above general formula (4), ^R2 is hydrogen or methyl, ^R3 is a substituted or unsubstituted linear alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and ^R4 is a substituted or unsubstituted alkyl group containing two or more phenyl groups, or a heteroatom-containing alkyl group containing two or more phenyl groups.

For example, the aforementioned alkyl group containing two or more substituted or unsubstituted phenyl groups, or the heteroatom-containing alkyl group containing two or more substituted or unsubstituted phenyl groups means that the two or more substituted or unsubstituted phenyl groups are not condensed but are linked by a single bond, an oxygen atom, a sulfur atom, a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, an alkylene group having 3 to 6 carbon atoms substituted or unsubstituted with a heteroatom, a vinylene group, an ethynylene group, or a carbonyl group. For example, the aforementioned alkyl group containing two or more substituted or unsubstituted phenyl groups, or the alkyl group containing a heteroatom containing two or more substituted or unsubstituted phenyl groups, may also include: substituted or unsubstituted biphenyl group, substituted or unsubstituted triphenylmethyl group, substituted or unsubstituted terphenyl group, substituted or unsubstituted extended biphenyl group, substituted or unsubstituted extended triphenyl group, substituted or unsubstituted extended tetraphenyl group, substituted or unsubstituted 2-phenyl-2-(phenylthio)ethyl group, substituted or unsubstituted 2,2-diphenylpropyl group, substituted or unsubstituted diphenylmethyl group, substituted or unsubstituted isopropylphenyl group, substituted or unsubstituted bisphenol F group, substituted or unsubstituted bisphenol A group, substituted or unsubstituted biphenyloxy group, substituted or unsubstituted terphenyloxy group, substituted or unsubstituted tetraphenyloxy group, substituted or unsubstituted pentphenyloxy group, etc., but are not limited thereto.

In one embodiment of the present invention, the monomer having two or more phenyl groups may be a di(meth)acrylate represented by the following general formula (5).

In the above general formula (5), ^R5 and ^R9 are independently hydrogen or methyl, ^R6 and ^R8 are independently substituted or unsubstituted linear alkylene groups having 1 to 10 carbon atoms, or substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, and ^R7 is a substituted or unsubstituted alkyl group containing two or more phenyl groups, or a heteroatom-containing alkyl group containing two or more phenyl groups.

For example, the aforementioned alkyl group containing two or more substituted or unsubstituted phenyl groups, or the heteroatom-containing alkyl group containing two or more substituted or unsubstituted phenyl groups means that the two or more substituted or unsubstituted phenyl groups are not condensed, but are linked by a single bond, an oxygen atom, a sulfur atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, an alkylene group having 3 to 6 carbon atoms substituted or unsubstituted with a heteroatom, an ethenylene group, an ethynylene group, or a carbonyl group. For example, the aforementioned alkyl group may also include: substituted or unsubstituted biphenylene group, substituted or unsubstituted triphenylmethylene group, substituted or unsubstituted triphenylene group, substituted or unsubstituted tetraphenylene group, 2-phenyl-2-(phenylthio)ethylene group, 2,2-diphenylpropylene group, diphenylmethylene group, etc., but is not limited thereto.

In the above general formula (1), a and b are integers of 0 to 2 respectively, and a+b is an integer of 1 to 4. In one example, a+b is an integer of 1 or 2.

The weight average molecular weight of the aforementioned monomer having two or more substituted or unsubstituted phenyl groups is preferably in the range of 100 to 1000 g/mol, more preferably in the range of 130 to 700 g/mol, and particularly preferably in the range of 150 to 600 g/mol. By setting it within the aforementioned range, a sealing film with better permeability can be provided.

The aforementioned photopolymerizable monomer (B) having an aromatic hydrocarbon group is preferably contained in an amount of 5 to 45% by mass, more preferably 10 to 40% by mass, relative to the total mass of the aforementioned photopolymerizable monomers (photopolymerizable monomer (A) and photopolymerizable monomer (B)). By setting it within the aforementioned range, the viscosity thereof will be suitable for forming a sealing film.

In addition, specific examples of the photopolymerizable monomers (A) and (B) include the monomers listed in the examples described below in addition to the above-mentioned monomers. The preferred combination of the photopolymerizable monomers in the present invention is as described in the examples described below.

<Photopolymerization initiator> The aforementioned photopolymerization initiator is not particularly limited as long as it is a common photopolymerization initiator capable of photopolymerization reaction. The photopolymerization initiator may include, for example, triazine, acetophenone, benzophenone, thioxanone, benzoin, phosphorus, oxime or a mixture thereof.

The triazine initiator may also be: 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(Trichloromethyl)-6-phenylvinyl-s-triazine, 2-(1-naphthalenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphthalen-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl(piperonyl)-6-triazine, 2,4-(trichloromethyl(4'-methoxyphenylvinyl)-6-triazine or a mixture thereof.

The acetophenone-based initiator may be 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone, p-t-butyltrichloroacetophenone, p-t-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 a mixture thereof.

The benzophenone-based initiator may be benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-2-methoxybenzophenone or a mixture thereof.

The thiothione-based initiator may be thiothione, 2-methylthiothione, isopropylthiothione, 2,4-diethylthiothione, 2,4-diisopropylthiothione, 2-chlorothiothione or a mixture thereof.

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

The phosphorus-based initiator may also be bis(benzoyl)phenylphosphine oxide, benzoyldiphenylphosphine oxide or a mixture thereof.

The oxime system may also be 2-(o-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione and 1-(o-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, or a mixture thereof.

The aforementioned photopolymerization initiator is preferably contained in the sealing composition of the present invention in a range of about 0.1 to 20 parts by mass relative to 100 parts by mass of the total of the aforementioned photopolymerizable monomer and the photopolymerization initiator. By setting it within the aforementioned range, photopolymerization can be fully initiated during exposure, and after photopolymerization, the transmittance can be prevented from being reduced due to the remaining unreacted initiator. Specifically, the aforementioned photopolymerization initiator is preferably contained in a range of 0.5 to 10 parts by mass, more specifically, in a range of 1 to 5 parts by mass. In addition, the aforementioned photopolymerization initiator is preferably contained in the sealing composition of the present invention in a range of 0.1 to 10% by mass based on the solid content, and more preferably in a range of 0.1 to 5% by mass. By setting it within the above range, photopolymerization can be fully initiated, and the reduction of transmittance due to residual unreacted initiator can be prevented.

In addition, instead of the above-mentioned photopolymerization initiator, a photoacid generator or photopolymerization initiator of a carbazole series, a diketone series, a cobalt series, an iodine series, a diazo series, a biimidazole series, or the like may be used.

<Other additives> The sealing composition of the present invention further contains other ingredients including antioxidants, heat stabilizers, photosensitizers, dispersants, thermal crosslinking agents and surfactants within the scope of obtaining the effects of the present invention. These ingredients may be contained in the sealing composition of the present invention in one kind or in two or more kinds.

The aforementioned antioxidant can improve the thermal stability of the sealing layer. The antioxidant may also include one or more selected from the group consisting of phenol, quinone, amine and phosphite, but is not limited to these. For example, as an antioxidant, tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane, tris(2,4-di-tert-butylphenyl)phosphite, etc. can be cited.

The antioxidant is preferably contained in the sealing composition in an amount of 0.01 to 3 parts by mass, more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the total of the photopolymerizable monomer and the photopolymerization initiator. By setting the amount within the above range, excellent thermal stability can be exhibited.

The aforementioned heat stabilizer is contained in the sealing composition to suppress the viscosity change of the sealing composition at room temperature, and a conventional heat stabilizer can be used without limitation. For example, a sterically resistant heat stabilizer can be used as a heat stabilizer. The phenolic heat stabilizer 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'-methane-bis(4-methyl-6-tert-butyl-phenol), 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(3,5-di-tert-butyl-4-hydroxyphenyl)-N,N'-hexamethylene-bispropionamide, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), stearyl-3,5-di-tert-butyl-4-hydroxyphenyl propionate, pentaerythritol tetrakis(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, 1,3,5-tris(2-hydroxyethyl) isocyanurate-tris(3,5-di-tert-butyl hydroxyphenyl propionate), but not limited thereto.

The thermal stabilizer is contained in the sealing composition in an amount of less than 2000 ppm, preferably in a range of 0.01 to 2000 ppm, and more preferably in a range of 100 to 1000 ppm, based on the solid content, relative to the total of the photopolymerizable monomer and the photopolymerization initiator. By setting the thermal stabilizer within the above range, the storage stability and processability of the sealing composition in a liquid state can be improved.

The aforementioned photosensitizer has the function of transferring the absorbed light energy to the photopolymerization initiator. Therefore, even if the photopolymerization initiator used does not absorb the light from the light source, it can still have the original photopolymerization initiator function. It is such a compound. As photosensitizers, for example, anthracene derivatives such as 9,10-dibutoxyanthracene; benzoin derivatives such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzophenone, o-benzoylbenzoic acid methyl ester, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, Benzophenone derivatives such as N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzyl ammonium bromide and (4-benzoylbenzyl)trimethylammonium chloride; 2-isopropylthioxanone, 4-isopropylthioxanone, 2,4-diethylthioxanone, 2,4-dichlorothioxanone, 1-chloro-4-propoxythioxanone, 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanone-9-one chloride; and other compounds. Among them, anthracene derivatives, benzoin derivatives, benzophenone derivatives, anthraquinone derivatives, and thioxanone derivatives are preferred.

<Ultraviolet curing> As the ultraviolet rays irradiated to cure the sealing composition of the present invention, known means can be used, and there is no particular limitation as long as the ultraviolet rays are irradiated in the range of 200 to 400 nm to cure. Ideally, from the viewpoint of preventing the degradation of electronic devices, it is preferable to use a 395 nm LED. As for the environment for irradiating ultraviolet rays, known means can be used as long as the sealing composition can be cured, and there is no particular limitation as long as the ultraviolet rays can be cured. Ideally, from the viewpoint of preventing the degradation of electronic components and preventing the influence of oxygen that hinders the curing, it is preferable to irradiate in an inert gas environment. In particular, it is preferable to irradiate in a nitrogen or argon atmosphere.

<Physical properties> The viscosity of the sealing composition of the present invention is in the range of 3 to 30 mPa·s, which is preferable from the viewpoint of further improving the ejection property of the inkjet head. The surface tension is greater than 15 mN/m and less than 45 mN/m, which is preferable from the viewpoint of further improving the ejection property of the inkjet head.

The viscosity of the sealing composition of the present invention can be obtained by measuring the temperature change of the dynamic viscoelasticity of the sealing composition, for example, using various rheometers. In the present invention, these viscosities are values obtained by the following method. The sealing composition of the present invention is placed in a stress-controlled rheometer Physica MCR300 (diameter of cone plate: 75 mm, cone angle: 1.0°, manufactured by Anton Paar). Next, the sealing composition is heated to 100°C, and the sealing composition is cooled to 20°C under the conditions of a cooling rate of 0.1°C/s, a distortion of 5%, and an angular frequency of 10radian/s, to obtain a temperature change curve of the dynamic viscoelasticity.

The sealing composition of the present invention may also contain pigment particles. From the perspective of further improving the ejection performance of the inkjet head, the average particle size of the pigment particles when the sealing composition of the present invention contains pigment 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. The average particle size of the pigment particles in the present invention means the value obtained by the dynamic light scattering method using Zetasizer Nano ZSP, manufactured by Malvern. In addition, since the sealing composition containing the coloring material has a high concentration and light cannot penetrate in the measuring machine, the sealing composition is diluted 200 times and then measured. The measuring temperature is set to room temperature (25°C).

Furthermore, the sealing composition of the present invention is such that the Ohnesorg number (Oh) shown in the following formula 1, where the density ρ, the surface tension σ of the sealing composition, the viscosity μ of the sealing composition, and the nozzle diameter D _0, falls within the range of 0.1 to 1, which is preferable from the viewpoint of the ejection properties of the inkjet and the stabilization of the droplets during the flight of the ink.

The sealing composition of the present invention is prepared to provide a hardened polymer having a Tg (glass transition point) of 80°C or higher in the film after polymerization. The Tg of the film after polymerization is preferably 80°C or higher from the perspective of ensuring stability in the formation process of the electronic device, the driving temperature, and the reliability test.

[Method for forming a sealing film for an electronic device] The method for forming a sealing film for an electronic device of the present invention is a method for forming a sealing film using the aforementioned electronic device sealing composition of the present invention, and is characterized by comprising: a process of forming a first sealing layer on an electronic device by a vapor phase method; and a process of forming a second sealing layer by applying the aforementioned electronic device sealing composition on the aforementioned first sealing layer. In addition, a process of forming a third sealing layer on the aforementioned second sealing layer by a vapor phase method is provided, which is preferable from the viewpoint of being able to further improve the sealing performance of the electronic device.

<First Sealing Layer Formation Process> The first sealing layer formation process is to form the first sealing layer on the electronic device by a vapor phase method. As the gas phase method, there can be cited: sputtering method (for example, reactive sputtering method including magnetron cathode sputtering, planar magnetron sputtering, diode AC planar magnetron sputtering, diode AC rotary magnetron sputtering, etc.), evaporation method (for example, resistance heating evaporation, electron beam evaporation, ion beam evaporation, plasma supported evaporation, etc.), thermal CVD method, catalytic chemical vapor phase growth method (Cat-CVD), capacitive coupled plasma CVD method (CCP-CVD), photo CVD method, plasma CVD method (PECVD), epitaxial growth method, atomic layer growth method (ALD) and other chemical evaporation methods, etc. Among them, formation by ALD method and CVD method is preferred. The first sealing layer contains silicon nitride (SiNx), silicon oxynitride (SiNOx) or silicon oxide (SiOx). A specific example of forming the first sealing layer is a method of reducing the pressure in a chamber and supplying silane ( _SiH4 ), ammonia ( _NH3 ) and hydrogen ( _H2 ) as raw material gases into the chamber after heating. The thickness of the first sealing layer is preferably in the range of 10 to 1000 nm, more preferably in the range of 100 to 500 nm.

<Second sealing layer forming process> The second sealing layer forming process is to form the second sealing layer by applying the aforementioned sealing composition of the present invention on the aforementioned first sealing layer. Specifically, it may also be a process comprising: applying the aforementioned sealing composition on the aforementioned first sealing layer (coating process), and subjecting the obtained coating film to vacuum ultraviolet irradiation in a nitrogen atmosphere for modification.

(Coating process) As a coating method for the sealing composition, any appropriate method can be adopted, for example: spin coating, roller coating, flow coating, inkjet coating, inkjet coating, printing, dip coating, casting film forming, rod coating, gravure printing, etc. Among them, the inkjet method is used, which is preferred from the perspective of being able to perform fine patterning as required when sealing electronic devices such as organic EL elements.

As the inkjet method, a known method can be used. The inkjet method can be roughly divided into two types: the on-demand drip method and the continuous method, and both can be used. The on-demand drip method includes an electro-mechanical conversion method (such as a single-chamber type, a double-chamber type, an elbow type, a piston type, a common mode type, a common wall type, etc.), an electro-thermal conversion method (such as a thermal inkjet type, a bubble jet (registered trademark) type, etc.), an electrostatic attraction method (such as an electric field control type, a slit jet type, etc.) and a discharge method (such as a flash jet type, etc.). From the perspective of the cost or productivity of the inkjet head, it is better to use a head using an electro-mechanical conversion method or an electro-thermal conversion method. In addition, the method of dripping liquid (such as coating liquid) is sometimes called "ink jet method" in conjunction with the ink jet method.

When applying the sealing composition, it is preferably done under a nitrogen atmosphere.

(Modification process) In the aforementioned modification process, after the coating process, the obtained coating film may be subjected to vacuum ultraviolet irradiation in a nitrogen atmosphere for modification. The so-called modification process is a conversion reaction of polysilazane to silicon oxide or silicon oxynitride. The modification process is also carried out in a nitrogen atmosphere or under reduced pressure in a glove box. The modification process in the present invention can be selected from known methods based on the conversion reaction of polysilazane. In the present invention, a conversion reaction using plasma, ozone or ultraviolet rays that can perform the conversion reaction at low temperature is preferred. Plasma or ozone can be used by previously known methods. In the present invention, the coating film is provided and irradiated with vacuum ultraviolet light (also called VUV) with a wavelength below 200nm to perform a modification treatment to form the second sealing layer described in the present invention.

The thickness of the second sealing layer is preferably in the range of 0.5 to 20 μm, more preferably in the range of 3 to 10 μm. In the second sealing layer, the entire layer may be a modified layer, but the thickness of the modified layer is preferably in the range of 1 to 50 nm, more preferably in the range of 1 to 30 nm.

In the above-mentioned process of irradiating vacuum ultraviolet rays for modification, the illumination of the vacuum ultraviolet rays received by the coating film on the coating film surface is preferably in the range of 30 to 200 mW/cm ² , and more preferably in the range of 50 to 160 mW/cm ^2. By setting the illumination of the vacuum ultraviolet rays to be above 30 mW/cm ² , the modification efficiency can be fully improved. When it is below 200 mW/cm ² , the occurrence rate of damage to the coating film can be greatly reduced, and the damage to the substrate can also be reduced, so it is preferred.

The irradiation energy of vacuum ultraviolet rays on the coating film surface is preferably in the range of 1 to 10 J/ ^cm2. From the perspective of maintaining the insulation and moisture and heat resistance required for the dehumidification function, it is preferably in the range of 3 to 7 J/ ^cm2 .

In addition, as a light source of vacuum ultraviolet light, a rare gas excimer lamp can be used ideally. Vacuum ultraviolet light is easily reduced in efficiency during vacuum ultraviolet light irradiation due to the presence of oxygen absorption, so vacuum ultraviolet light irradiation is preferably carried out under a state of low oxygen concentration as much as possible. That is, the oxygen concentration during vacuum ultraviolet light irradiation is preferably set in the range of 10 to 10000 ppm, preferably in the range of 50 to 5000 ppm, more preferably in the range of 80 to 4500 ppm, and most preferably in the range of 100 to 1000 ppm.

The reforming treatment can also be combined with the heat treatment. The heating conditions are preferably in the range of 50 to 300°C, preferably in the range of 60 to 150°C, and preferably in the range of 1 second to 60 minutes, preferably in the range of 10 seconds to 10 minutes. By combining the heat treatment, the dehydration condensation reaction during reforming can be promoted, and the reformed body can be formed more efficiently.

As the heat treatment, for example, there can be cited a method of heating the coating by heat conduction by bringing the substrate into contact with a heating element such as a heating block, a method of heating the atmosphere by an external heater such as a resistance wire, a method of using infrared light such as an IR heater, etc., but there are no particular limitations. In addition, a method that can maintain the smoothness of the coating containing the silicon compound can be appropriately selected.

<Third Sealing Layer Formation Process> The third sealing layer formation process is to form the third sealing layer on the second sealing layer by a vapor phase method. As the gas phase method, similar to the gas phase method used in the process of forming the first sealing layer, there can be cited: sputtering method (for example, reactive sputtering method including magnetron cathode sputtering, planar magnetron sputtering, diode AC planar magnetron sputtering, diode AC rotary magnetron sputtering, etc.), evaporation method (for example, resistance heating evaporation, electron beam evaporation, ion beam evaporation, plasma supported evaporation, etc.), thermal CVD method, catalytic chemical vapor phase growth method (Cat-CVD), capacitive coupled plasma CVD method (CCP-CVD), photo CVD method, plasma CVD method (PE-CVD), epitaxial growth method, chemical evaporation method such as atomic layer growth method (ALD), etc. Among them, it is preferably formed by the ALD method or the CVD method. The third sealing layer contains silicon nitride (SiNx), silicon oxynitride (SiNOx) or silicon oxide (SiOx). As a specific example of forming the third sealing layer, there is a method in which the pressure in the chamber is first reduced, and silane ( _SiH4 ), ammonia ( _NH3 ), and hydrogen ( _H2 ) are heated and then supplied into the chamber as raw material gases. 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.

In addition, as mentioned above, after the sealing film is formed, a conductive film for a touch sensor can be further formed. The conductive film can be formed by a graphene film with excellent flexibility, a metal nanowire film (e.g., a film containing silver nanowires or copper nanowires), or a metal nanoparticle film (e.g., a film containing silver nanoparticles or copper nanoparticles) in addition to a metal compound film such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). In addition, it can also be formed by a multilayer film of multiple metals such as Al film/Ti film/Al film.

[Electronic device sealing film] The electronic device sealing film of the present invention is an electronic device sealing film for sealing an electronic device, and is characterized by having: 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. The electronic device sealing film of the present invention is formed by the electronic device sealing film forming method. That is, the second sealing layer is formed using the electronic device sealing composition of the present invention. In addition, the electronic device sealing film of the present invention preferably further has a third sealing layer containing silicon nitride, silicon oxide or silicon oxynitride on the second sealing layer.

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

<Second sealing layer> The second sealing layer is provided adjacent to the first sealing layer and is formed by applying the sealing composition on the first sealing layer. Therefore, the second sealing layer contains a polymer composed of a specific photopolymerizable monomer contained in the sealing composition.

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

The content of the polymer in the second sealing layer is preferably in the range of 85 to 100 mass %, more preferably in the range of 90 to 95 mass %.

<Third sealing layer> The third sealing layer is provided adjacent to the second sealing layer and is formed by the aforementioned vapor phase method. Specifically, it contains silicon nitride, silicon oxide (silicon monoxide, silicon dioxide, etc.) or silicon oxynitride, similar to the first sealing layer.

[Electronic device] In the electronic device sealing film forming method and 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, a liquid crystal display element (LCD), a thin film transistor, a touch panel, an electronic paper, a solar cell (PV), etc. From the perspective of more efficiently obtaining the effect of the present invention, an organic EL element, a solar cell or an LED element is preferred, and an organic EL element is particularly preferred.

<Organic EL element> The organic EL element used as the electronic device described in the present invention may also be a bottom emission type, that is, light is extracted from the transparent substrate side. Specifically, the bottom emission type is formed by sequentially stacking a transparent electrode as a cathode, a light-emitting functional layer, and a counter electrode as an anode on a transparent substrate. In addition, the organic EL element described in the present invention may also be a top emission type, that is, light is extracted from the side of the transparent electrode as a cathode opposite to the substrate. Specifically, the top emission type is a structure in which a counter electrode serving as an anode is set on the substrate side, and a light-emitting functional layer and a transparent electrode serving as a cathode are sequentially stacked on its surface.

The following discloses a representative example of the structure of an organic EL element. (i) Anode/hole injection transport layer/luminescent layer/electron injection transport layer/cathode (ii) Anode/hole injection transport layer/luminescent layer/hole blocking layer/electron injection transport layer/cathode (iii) Anode/hole injection transport layer/electron blocking layer/luminescent layer/hole blocking layer/electron injection transport layer/cathode (iv) Anode/hole injection layer/hole transport layer/luminescent layer/electron transport layer/electron injection layer/cathode (v) Anode/hole injection layer/hole transport layer/luminescent layer/hole blocking layer/electron transport layer/electron injection layer/cathode (vi) Anode/hole injection layer/hole transport layer/electron blocking layer/luminescent layer/hole blocking layer/electron transport layer/electron injection layer/cathode Furthermore, the organic EL element may also have a non-luminescent intermediate layer. The intermediate layer may also be a charge generating layer or may be composed of a multi-photon unit. As for the outline of the organic EL element applicable to the present invention, for example, Japanese Patent Publication No. 2013-157634, Japanese Patent Publication No. 2013-168552, Japanese Patent Publication No. 2013-177361, Japanese Patent Publication No. 2013-187211, Japanese Patent Publication No. 2013-191644, Japanese Patent Publication No. 2013-191804, Japanese Patent Publication No. 2013-225678, Japanese Patent Publication No. 2013-235994, Japanese Patent Publication No. 2013- The structure described in Japanese Patent Publication No. 243234, Japanese Patent Publication No. 2013-243236, Japanese Patent Publication No. 2013-242366, Japanese Patent Publication No. 2013-243371, Japanese Patent Publication No. 2013-245179, Japanese Patent Publication No. 2014-003249, Japanese Patent Publication No. 2014-003299, Japanese Patent Publication No. 2014-013910, Japanese Patent Publication No. 2014-017493, Japanese Patent Publication No. 2014-017494, etc.

<Substrate> As a substrate that can be used in the above-mentioned organic EL element (hereinafter also referred to as a supporting substrate, substrate, substrate, support, etc.), specifically, glass or resin film is preferably used. When flexibility is required, resin film is preferred. In addition, it can be transparent or opaque. In the case of a bottom emission type in which light is extracted from the substrate side, the substrate is preferably transparent.

Preferred resins include polyester resins, methacrylic acid resins, methacrylic acid-maleic acid copolymers, polystyrene resins, transparent fluorine resins, polyimide, fluorinated polyimide resins, polyamide resins, polyamide imide resins, polyether imide resins, cellulose acylate resins, polyamine resins, A base material of a thermoplastic resin such as formate resin, polyetheretherketone resin, polycarbonate resin, alicyclic polyolefin resin, polyacrylate resin, polyethersulfone resin, polysulfone resin, cycloolefin copolymer, fluorene ring-modified polycarbonate resin, alicyclic modified polycarbonate resin, fluorene ring-modified polyester resin, acrylic compound, etc. The resin may be used alone or in combination of two or more.

The substrate is preferably made of a heat-resistant material. Specifically, a substrate having a linear expansion coefficient of 15ppm/K to 100ppm/K and a glass transition temperature (Tg) of 100°C to 300°C is used. This substrate meets the necessary conditions for use in electronic components and as a laminated film for displays. That is, when the sealing film of the present invention is used in these applications, the substrate is sometimes exposed to a process above 150°C. In this case, if the linear expansion coefficient of the substrate exceeds 100ppm/K, the substrate size will be unstable during the process at the above-mentioned temperature, and it will be accompanied by thermal expansion and contraction, resulting in the disadvantage of deterioration of the shielding performance, or the disadvantage of being unable to withstand the heat process. When the concentration is less than 15ppm/K, the film will break like glass, resulting in deterioration of flexibility.

The Tg or linear expansion coefficient of the substrate can be adjusted by additives, etc. Preferred specific examples of thermoplastic resins that can be used as substrates include polyethylene terephthalate (PET: 70°C), polyethylene naphthalate (PEN: 120°C), polycarbonate (PC: 140°C), alicyclic polyolefins (e.g., ZEONOR manufactured by Zeon Corporation of Japan) and polyolefins (e.g., ZEONOR manufactured by Zeon Corporation of Japan). (Registered trademark) 1600: 160°C), polyacrylate (PAr: 210°C), polyether sulfone (PES: 220°C), polysulfone (PSF: 190°C), cycloolefin copolymer (COC: compound described in Japanese Patent Application Laid-Open No. 2001-150584: 162°C), polyimide (e.g. NEOPULIM manufactured by Mitsubishi Gas Chemical Co., Ltd. (Registered trademark: 260°C) , fluorene ring modified polycarbonate (BCF-PC: compounds described in Japanese Patent Publication No. 2000-227603: 225°C), alicyclic modified polycarbonate (IP-PC: compounds described in Japanese Patent Publication No. 2000-227603: 205°C), acryl compounds (compounds described in Japanese Patent Publication No. 2002-80616: above 300°C), etc. (temperatures in parentheses represent Tg).

The electronic device described in the present invention is an electronic device such as an organic EL element, so the substrate is preferably transparent. That is, the light transmittance is usually above 80%, preferably above 85%, and more preferably above 90%. The light transmittance is measured using the method described in JIS K7105:1981, that is, using an integrating sphere light transmittance measuring device to measure the total light transmittance and the amount of scattered light, and can be calculated by subtracting the diffused transmittance from the total light transmittance.

Furthermore, the substrates listed above may be unstretched films or stretched films. The substrates may be manufactured by a conventional method known in the art. The manufacturing methods of these substrates may be appropriately described in paragraphs "0051" to "0055" of International Publication No. 2013/002026.

The surface of the substrate may be subjected to various known treatments required to improve adhesion, such as corona discharge treatment, flame treatment, oxidation treatment, or plasma treatment, and the above treatments may be combined as needed. In addition, the substrate may be subjected to an easy-to-bond treatment.

The substrate may be a single layer or a multilayer structure of two or more layers. When the substrate is a multilayer structure of two or more layers, each substrate may be of the same type or of different types.

The thickness of the substrate of the present invention (the total thickness in the case of a multilayer structure with more than two layers) is preferably 10 to 200 μm, more preferably 20 to 150 μm.

In the case of a film substrate, a film substrate with a gas barrier layer is preferred.

The gas barrier layer for the film substrate may be an inorganic, organic film or a mixed film of the two formed on the surface of the film substrate. Preferably, the gas barrier layer has a water vapor permeability (25±0.5°C, relative humidity (90±2)%RH) of 0.01g/m ² ･24h or less as measured in accordance with the method of JIS K 7129-1992. More preferably, the gas barrier layer has an oxygen permeability of 1×10 ^-3 mL/m ² ･24h･atm or less as measured in accordance with the method of JIS K 7126-1987 and a water vapor permeability of 1×10 ^-3 g/m ² ･24h or less.

The gas barrier layer may be formed of any material capable of inhibiting the penetration of moisture, oxygen, or other substances that may cause device degradation. Examples of the materials that may be used include silicon monoxide, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, and silicon oxycarbide.

The gas barrier layer is not particularly limited, but in the case of an inorganic gas barrier layer such as silicon monoxide, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbide, etc., the inorganic material is sputtered (such as magnetron cathode sputtering, planar magnetron sputtering, diode AC planar magnetron sputtering, diode AC rotary magnetron sputtering, etc.), evaporation (such as resistance heating evaporation, electron beam evaporation, etc.) The layer formation is preferably performed by chemical evaporation methods such as evaporation, ion beam evaporation, plasma supported evaporation, etc.), thermal CVD, catalytic chemical vapor deposition (Cat-CVD), capacitive coupled plasma CVD (CCP-CVD), photo CVD, plasma CVD (PE-CVD), epitaxial growth, atomic layer deposition (ALD), reactive sputtering, etc.

Furthermore, after a coating liquid containing an inorganic precursor such as polysilazane, tetraethyl orthosilicate (TEOS), etc. is coated on a support, it is modified by irradiation with vacuum ultraviolet light to form an inorganic gas insulation layer, or the inorganic gas insulation layer can be formed by a thin film metallization technique such as metal plating on a resin substrate to bond a metal foil to the resin substrate.

Furthermore, the inorganic gas barrier layer may include an organic layer including an organic polymer. In other words, the inorganic gas barrier layer may be a laminate of an inorganic layer including an inorganic material and an organic layer.

The organic layer is formed, for example, by coating an organic monomer or an organic oligomer on a resin substrate to form a layer, and then polymerizing and crosslinking as needed using, for example, an electron beam device, a UV light source, a discharge device, or other suitable devices. Alternatively, for example, an organic monomer or an organic oligomer that can be flash evaporated and crosslinked by radiation is evaporated to form a polymer from the organic monomer or an organic oligomer. The coating efficiency can be improved by cooling the resin substrate.

Examples of coating methods for the organic monomer or the organic oligomer include roll coating (e.g., gravure roll coating), spray coating (e.g., electrostatic spray coating), etc. Examples of laminates of inorganic and organic layers include laminates described in International Publication No. 2012/003198 and International Publication No. 2011/013341.

In the case of an inorganic layer and an organic layer laminate, the thickness of each layer may be the same or different. 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. [Example]

The following examples are given to specifically illustrate the present invention, but the present invention is not limited to these examples. In addition, in the following examples, unless otherwise stated, the operations are all carried out at room temperature (25° C.). In addition, unless otherwise stated, "%" and "parts" mean "mass %" and "mass parts" respectively.

[Monomers] The monomers used in the preparation of the sealing composition are shown below. The dipole moment (μ), dispersion term (δD), polar term (δP), hydrogen bond term (δH) and molecular volume (V) of each monomer are shown in the table below. The dipole moment (μ) of the monomer was obtained based on the chemical structure information of the monomer using Gaussian software manufactured by HULINKS to obtain the dipole moment μ (Debye unit) of each monomer. PM6, a semi-empirical method, was used in the calculation. In addition, the hydrogen bonding term (δH) and molecular volume (V) of the monomers were obtained based on the chemical structure information using the Hansen Solubility Parameters in Practice (HSPiP) software to obtain δH (unit: MPa ^1/2 ) and V (unit: cm ³ ･mol ^-1 ) of each monomer. In addition, the dispersion term component δD and the polar term component δP (unit: MPa ^1/2 ) were also obtained at the same time.

[Preparation of Sealing Compositions 1 to 78] Each monomer was weighed in a nitrogen atmosphere in the manner of the type and mass fraction shown in Tables III to VI below. Furthermore, 5 mass fractions of a phosphorus-based initiator (Omnirad 819 manufactured by IGM) as a photopolymerization initiator and 0.5 mass fractions of 2-isopropylthioxanone (manufactured by Merck) as a sensitizer were placed in a brown bottle, and stirred on a heating plate at 65°C for 3 hours to obtain each sealing composition 1 to 78.

[S1 and S2] Based on the dipole moment (μ), dispersion term (δD), polar term (δP), hydrogen bond term (δH) and molecular volume (V) of each monomer obtained above, S1 and S2 in each sealing composition were calculated by the following formula and are shown in the table below. (In the above formula, m is the molar ratio of the monomer, and the suffixes of m, μ, V, and δH are the numbers of the monomers.) In addition, the table below also shows the "average value of the molar ratio-converted dipole moment of each monomer (μ) [Debye] (m1×μ1+m2×μ2+･･･)", "average value of the molar ratio-converted hydrogen bond term of each monomer (δH) [MPa ^1/2 ] (m1×δH1+m2×δH2+･･･)" and "average value of the molar ratio-converted molecular volume of each monomer (V) [cm ³ ･mol ^-1 ] (m1×V1+m2×V2+･･･)".

[Evaluation] <Relative dielectric constant> A coating of a sealing composition with a thickness of 50 μm was prepared on a release film substrate with a size of 100 mm × 100 mm in a nitrogen environment. The coating was irradiated with ultraviolet light (MZ 240 mm 395 nm UVLED manufactured by IST) at a wavelength of 395 nm at 300 mW/cm ² in a nitrogen environment so that the integrated light intensity would be 1.5 mJ/cm ² , and the coating was cured. The obtained cured film was peeled off from the release film, and then a Ag film was formed on both sides by sputtering and used as a measurement sample. The sample was measured by impedance measurement with an impedance measuring device (Solartron 126096) at a frequency of 100kHz and AC 0.1 (V), and the relative dielectric constant was measured. A relative dielectric constant of 3.1 or less was considered acceptable, and a relative dielectric constant of more than 3.1 was considered unacceptable.

<Inkjet ejection stability> In a nitrogen environment, the sealing composition was filled into the inkjet head (KM1024i-MHE-D manufactured by Konica Minolta). Ink was ejected from the inkjet head at a frequency of 5kHz, and 256 nozzles were observed. The presence or absence of droplets ejected from the 256 nozzles and the volume of the droplets ejected were observed, and the average value, maximum value, and minimum value of the volume were measured. The volume variation rate was calculated by the following formula. Volume variation rate = (maximum value - average value) ÷ average value × 100 Or Volume variation rate = (average value - minimum value) ÷ average value × 100 The larger value of the above two volume variation rates was used. The following evaluation criteria are used to judge the presence or absence of droplet discharge and the volume change rate. Ratings 3 and 4 are considered passing.

(Evaluation criteria) Rating 1: The number of nozzles not ejected is 10 or more, or the number of nozzles not ejected is less than 10 and the volume change rate is 20% or more Rating 2: The number of nozzles not ejected is less than 10 and the volume change rate is 10% or more and less than 20% Rating 3: The number of nozzles not ejected is less than 10 and the volume change rate is 5% or more and less than 10% Rating 4: The number of nozzles not ejected is less than 10 and the volume change rate is less than 5%

[Fabrication of organic EL elements] (1) Preparation of substrates A 15 μm polyimide film was prepared as a thin film substrate. Then, a gas barrier layer for a thin film substrate ( _SiO2 film: 250 nm/SiNx film: 50 nm/ _SiO2 film: 500 nm (upper layer/middle layer/lower layer)) was formed on the polyimide film by plasma CVD.

(2) Formation of the first electrode An Al film was formed as the first electrode (metal layer) on one surface of the substrate under the following conditions. The thickness of the formed first electrode was 150 nm. The thickness of the first electrode was the value measured by a contact surface profile meter (DECTAK). The Al film was formed by using a tungsten resistance heating crucible after reducing the pressure to a vacuum degree of 1×10 ^-4 Pa using a vacuum evaporation device.

(3) Formation of organic EL layer First, each of the evaporation crucibles in the vacuum evaporation device is filled with the following materials constituting each layer of the organic functional layer in an amount most suitable for the production of each element. The evaporation crucible is made of a resistor heating material made of molybdenum or tungsten.

(3-1) Formation of Hole Injection Layer After reducing the pressure to a vacuum degree of 1×10 ^-4 Pa, the evaporation crucible containing the following compound A-1 was energized and heated, and a hole injection layer with a thickness of 10 nm was formed on the first electrode (metal layer side) at an evaporation rate of 0.1 nm/sec.

(3-2) Formation of hole transport layer Next, the evaporation crucible containing the following compound M-2 was energized and heated, and evaporation was performed on the hole injection layer at an evaporation rate of 0.1 nm/sec to form a hole transport layer with a thickness of 30 nm.

(3-3) Formation of luminescent layer Next, the following compound BD-1 and the following compound H-1 were co-evaporated at a deposition rate of 0.1 nm/sec so that the concentration of compound BD-1 was 7% by mass, thereby forming a luminescent layer (fluorescent luminescent layer) having a thickness of 15 nm and emitting blue light. Next, the following compound GD-1, the following compound RD-1, and the following compound H-2 were co-evaporated at a deposition rate of 0.1 nm/sec so that the concentration of compound GD-1 was 20% by mass and the concentration of RD-1 was 0.5% by mass, thereby forming a luminescent layer (phosphorescent luminescent layer) having a thickness of 15 nm and emitting yellow light.

(3-4) Formation of electron transport layer Subsequently, a heating boat containing the following compound T-1 as an electron transport material was energized to form an electron transport layer made of Alq ₃ (tris(8-hydroxyquinoline)) on the light-emitting layer. At this time, the evaporation rate was set within the range of 0.1 to 0.2 nm/sec and the thickness was set to 30 nm.

(3-5) Formation of electron injection layer (metal affinity layer) Next, the heating boat containing the following compound I-1 as an electron injection material is energized and heated to form an electron injection layer made of Liq on the electron transport layer. At this time, the evaporation rate is set to a range of 0.01 to 0.02 nm/sec, and the thickness is set to 2 nm. In addition, the electron injection layer functions as a metal affinity layer. In this way, an organic EL layer that emits white light is formed.

(4) Formation of the second electrode Then, a Mg/Ag mixture (Mg:Ag=1:9 (vol ratio)) was evaporated to a thickness of 10nm to form the second electrode and its extraction electrode.

(5) Formation of a capping layer Afterwards, the film was transferred to the original vacuum chamber, and α-NPD (4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl) was evaporated on the second electrode at a deposition rate of 0.1 to 0.2 nm/sec until the thickness reached 40 nm, forming a capping layer for improving the light extraction amount.

(6) Formation of the first sealing layer Next, as the first sealing layer to cover the light-emitting portion of the organic EL element manufactured above, silicon nitride (SiNx, Vickers hardness HV900) with a thickness of 500 nm is formed by plasma CVD.

(7) Formation of the Second Sealing Layer Next, the sealing composition 1 prepared above was filled into an inkjet head (KM1024i-MHE-D manufactured by Konica Minolta) in a nitrogen atmosphere. Then, the organic EL element formed up to the first sealing layer was coated with the sealing composition 1 in a nitrogen atmosphere using an inkjet method so that the coating thickness reached 10 μm. Thereafter, ultraviolet light of a wavelength of 395 nm (MZ 240mm 395nm UVLED manufactured by IST) was irradiated at 300 mW/ ^cm2 so that the integrated light amount would be 1.5 J/ ^cm2 , thereby forming the second sealing layer.

(8) Formation of the third sealing layer Next, silicon nitride (SiNx, Vickers hardness HV900) was formed to a thickness of 500 nm on the second sealing layer as the third sealing layer by plasma CVD, and an organic EL element 1 for evaluation having the first to third sealing layers formed thereon was obtained.

[Production of organic EL elements 2 to 78] In the production of the aforementioned organic EL element 1, the sealing composition 1 used in the formation of the aforementioned second sealing layer was changed as shown in the following table, and organic EL elements 2 to 78 for evaluation were produced in the same manner.

[Evaluation] ＜Luminescence characteristics (luminescence residual rate)＞ Each organic EL element for evaluation was placed in a constant temperature chamber in a high temperature environment (temperature 85°C) and subjected to an accelerated degradation test. After 200 hours, each organic EL element was taken out of the constant temperature chamber and driven at a constant voltage at room temperature to emit light, and the luminescence intensity was measured. The ratio (%) of the luminescence intensity after the accelerated degradation test to the luminescence intensity before the accelerated degradation test was measured and judged according to the following criteria. Ratings 2 to 4 were considered qualified. (Evaluation criteria) Rating 1: less than 80% Rating 2: 80% or more, less than 90% Rating 3: 90% or more, less than 95% Rating 4: 95% or more

<Crack resistance> A 15μm polyimide film was prepared as a film substrate. Then, a sealing layer was formed on the polyimide film in the same manner as the aforementioned (6) formation of the first sealing layer, (7) formation of the second sealing layer, and (8) formation of the third sealing layer, and this was used as an evaluation sample. The evaluation sample was bent with a bending radius of R = 1.5 mm so that the side of the polyimide film was convex. It was fixed in the bent state and kept in an environment of -20°C for 24 hours. The evaluation sample was taken out and observed under a microscope for the presence of cracks and film peeling, and judged using the following evaluation criteria. Ratings 2 to 4 were considered acceptable. (Evaluation criteria) Rating 1: There is membrane peeling, or more than 10 cracks Rating 2: No membrane peeling, and more than 5 to less than 10 cracks Rating 3: No membrane peeling, and more than 2 to less than 5 cracks Rating 4: No membrane peeling, and less than 2 cracks

As shown in the above results, the sealing composition of the present invention has better discharge stability due to the inkjet method than the sealing composition of the comparative example, and can form a sealing film with a relatively low dielectric constant. It can also be seen that the organic EL element sealed using the sealing composition of the present invention has excellent luminescence characteristics and crack resistance.

Claims (8)

An electronic device sealing composition comprising a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer is composed of (meth)acrylate; the following S1 calculated based on the dipole moment μ[Debye], molecular volume V[cm ³ ‧mol ^-1 ] and hydrogen bonding term δH[MPa ^1/2 ] of the photopolymerizable monomer is in the range of 0.10×10 ^-2 ~1.10×10 ^-2 [Debye/(cm ³ ‧mol ^-1 )], or the following S2 is in the range of 0.50×10 ^-2 ~1.50×10 ^-2 [MPa ^1/2 /(cm ³ ‧mol ^-1 )]: S1=(m1× μ 1+m2× μ 2+‧‧‧)/(m1×V1+m2×V2+‧‧‧) S2=(m1× δ H1+m2× δ H2+‧‧‧)/(m1×V1+m2×V2+‧‧‧)(In the above formula, m is the molar ratio of the monomer, and the suffixes of m, μ, V and δH are the numbers of the monomers). The electronic device sealing composition as recited in claim 1, wherein the S1 is in the range of 0.50×10 ^-2 to 0.80×10 ^-2 [Debye/(cm ³ ·mol ^-1 )], or the S2 is in the range of 0.50×10 ^-2 to 1.00×10 ^-2 [MPa ^1/2 /(cm ³ ·mol ^-1 )]. The electronic device sealing composition as recited in claim 1, wherein the hydrogen bonding term δH is in the range of 1.9 to 3.5 MPa ^1/2 . An electronic device sealing film is an electronic device sealing film for sealing an electronic device, characterized by having: a first sealing layer containing: silicon nitride, silicon oxide or silicon oxynitride; and a second sealing layer using an electronic device sealing composition as described in any one of claim 1 to claim 3. The electronic device sealing film as described in claim 4, wherein a third sealing layer is provided on the aforementioned second sealing layer, and the third sealing layer contains silicon nitride, silicon oxide or silicon oxynitride. A method for forming an electronic device sealing film is a method for forming an electronic device sealing film using an electronic device sealing composition as described in any one of claim 1 to claim 3, characterized by comprising: a process of forming a first sealing layer on an electronic device by a vapor phase method; and a process of forming a second sealing layer by applying the electronic device sealing composition on the first sealing layer. The method for forming a sealing film for an electronic device as described in claim 6 comprises: forming a third sealing layer on the aforementioned second sealing layer by a vapor phase method. The method for forming a sealing film for an electronic device as described in claim 6, wherein the second sealing layer is formed by an inkjet method.