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

Abstract

This composition for sealing an electronic device for inkjet contains a photopolymerizable monomer and a photopolymerization initiator. The photopolymerizable monomer is (meth)acrylate. The density of the uncured sealing composition at 25°C is within the range of 0.85-1.08 g / cm3, and the moisture content thereof measured by the Karl Fischer method is 100 ppm by mass or less. Said moisture content is preferably 5 ppm by mass or more.

Description

Inkjet electronic device sealing composition, electronic device sealing film, and method for forming electronic device sealing film

[0001] The present invention relates to an inkjet composition for sealing an electronic device, an electronic device sealing film, and a method for forming an electronic device sealing film. In particular, the present invention relates to a composition for sealing an electronic device that can suppress the occurrence of scratches on the sealing film and prevent image defects during continuous use of the device.

[0002] Organic electroluminescent elements used in electronic devices, particularly organic electroluminescent devices, are sealed by a sealing film with a multilayer structure formed from an inorganic protective layer and an organic protective layer. Hereinafter, the organic electroluminescent device will also be referred to as an "organic EL device." The organic electroluminescent element will also be referred to as an "organic EL element." The sealing film is formed by laminating an inorganic protective layer on an organic protective layer using plasma or the like. To prevent damage to the organic protective layer during this process, an acrylic resin with excellent mechanical properties is preferably used. An inkjet method is preferably used to form the organic protective layer, as it is simple and allows for easy control of film thickness. In recent years, there has been a demand for thinner sealing films, particularly organic protective layers, in order to make devices lighter, foldable, and rollable.

[0003] However, when using a thin encapsulation film in a foldable or rollable device, scratches sometimes occur within the device, affecting visibility. Furthermore, it was found that fine wrinkle-like defects appear on the image with continued use of the device.

[0004] For example, Patent Document 1 discloses controlling the specific gravity of a sealant containing a polymerizable monomer and a polymerization initiator. However, Patent Document 1 does not disclose any means for controlling density from the viewpoint of scratch prevention. Furthermore, while it is generally known that moisture deteriorates organic light-emitting materials, the effect of moisture on the physical properties of the film surface of the sealant is not known.

[0005] JP 2023-22039 A

[0006] The present invention has been made in consideration of the above problems and circumstances. The problem to be solved by the present invention is to provide an inkjet electronic device sealing composition that can prevent scratches on the sealing film when the device is transported or wound into a roll. Another object of the present invention is to provide an inkjet electronic device sealing composition that can prevent image defects during continuous use of the device. Furthermore, an electronic device sealing film and a method for forming an electronic device sealing film using the sealing composition are provided.

[0007] The present inventors have investigated the causes of the above problems in order to solve the above problems. They have found that a composition for sealing electronic devices that can prevent scratches on the sealing film and image defects can be provided by controlling the density at 25°C and the water content of the uncured sealing composition within specific ranges. That is, the above problems according to the present invention are solved by the following means.

[0008] 1. An inkjet composition for electronic device sealing, which contains a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer contains a (meth)acrylate, and the density of the uncured sealing composition at 25°C is 0.85 to 1.08 g / cm ３ and the water content measured by the Karl Fischer method is 100 ppm by mass or less.

[0009] 2. The composition for electronic device encapsulation for ink jet printing according to item 1, wherein the water content is 5 ppm by mass or more.

[0010] 3. The inkjet electronic device sealing composition according to item 1, wherein when inkjet ejection of the sealing composition is interrupted and then re-ejected, the latency at which the change in droplet velocity before and after interruption of ejection is ±3% or less is 20 seconds or more.

[0011] 4. The density of the uncured sealing composition at 25°C is 0.94 to 1.05 g / cm ３ 2. The composition for electronic device encapsulation for ink jet printing according to claim 1, wherein the composition is in the range of

[0012] 5. The electronic device sealing composition for inkjet printing according to item 1, wherein the total content of aluminum (Al), iron (Fe), and sodium (Na) contained in the sealing composition is 1 mass ppm or less with respect to the total amount of the sealing composition.

[0013] 6. The composition for sealing an electronic device for ink jet printing according to item 1, wherein the average number of oxygen atoms contained in one molecule of all of the photopolymerizable monomers is 2.5 or more and 3.0 or less.

[0014] 7. The inkjet electronic device sealing composition according to item 1, wherein, when the spectral transmission spectrum of the sealing composition is measured, a light transmittance-light wavelength peak curve is obtained by normalizing the transmittance at a transmitted light wavelength of 650 nm to 100%, where the slope of the tangent at a wavelength of 450 nm is within the range of 2.5 to 5.0% / nm.

[0015] 8. The composition for electronic device encapsulation for ink jet printing according to item 1, wherein all of the photopolymerizable monomers contain 30% by mass or more of monomers having 3 or less double bonds in one molecule.

[0016] 9. A method for producing the composition for sealing an electronic device according to any one of items 1 to 8, comprising the steps of preparing a solution of the photopolymerizable monomer and the photopolymerization initiator, and then dehydrating the solution.

[0017] 10. The method for producing a composition for sealing electronic devices according to item 9, further comprising a degassing step after the solution preparation step.

[0018] 11. The method for producing a composition for sealing electronic devices according to item 9, further comprising a step of filtering the composition through a metal-removing filter after the step of preparing the composition.

[0019] 12. An electronic device sealing film for sealing an electronic device, comprising: an inorganic protective layer containing silicon nitride, silicon oxide, or silicon oxynitride; and an organic protective layer formed using the electronic device sealing composition according to any one of items 1 to 8.

[0020] 13. The density of the organic protective layer at 25°C is 0.85 to 1.08 g / cm ３ 13. The electronic device sealing film according to item 12,

[0021] 14. The electronic device sealing film according to item 12, wherein the organic protective layer contains at least a monomer having an average number of oxygen atoms in one molecule of 2.5 to 3.0 or a monomer having 3 or less double bonds in one molecule.

[0022] 15. A method for forming an encapsulating film using the composition for encapsulating an electronic device according to any one of items 1 to 8, comprising: forming an inorganic protective layer on an electronic device by a vapor phase method; and forming an organic protective layer by applying the composition for encapsulating an electronic device on the inorganic protective layer.

[0023] 16. The method for forming an electronic device sealing film according to item 15, further comprising the step of forming a second inorganic protective layer containing silicon nitride, silicon oxide or silicon oxynitride on the organic protective layer by a vapor phase method.

[0024] 17. The method for forming an electronic device sealing film according to item 15, wherein an ink-jet method is used in the step of forming the organic protective layer.

[0025] The above-described means of the present invention can provide an inkjet electronic device sealing composition that can prevent scratches on the sealing film when the device is transported or wound into a roll. It can also provide an inkjet electronic device sealing composition that can prevent image defects during continuous use of the device. Furthermore, it can provide an electronic device sealing film and a method for forming an electronic device sealing film using the sealing composition. The mechanism by which the effects of the present invention are manifested or acted upon is not clearly understood, but is speculated as follows.

[0026] <Scratch Occurrence> (Estimated Cause of Occurrence) Scratch-like damage occurs on the encapsulating film when the device is handled during transportation, etc., and especially when it is wound into a roll. In particular, in thin films, slight deviations in film thickness or uneven curing of the organic protective layer can cause uneven mechanical strength, resulting in localized loads during handling, which are thought to cause scratches.

[0027] (Countermeasure) Therefore, the present invention aims to reduce the density of the uncured sealing composition at 25°C to 0.85 to 1.08 g / cm ３ The density was set within the range of 0.85 g / cm, and the moisture content measured by the Karl Fischer method was adjusted to 100 ppm by mass or less. It was found that this prevents the occurrence of scratches on the sealing film and image defects. In other words, it is presumed that adjusting the density and moisture content imparts hardness and flexibility to the surface of the sealing film, so that, for example, pressure is applied uniformly during transportation or when wound into a roll, thereby improving scratches. The density of the uncured sealing composition was set within the above range because the density was 0.85 g / cm ３ If the density is lower than 1.08 g / cm, the hardness of the film when cured is insufficient and it is prone to scratches. ３ If the density is higher, the film becomes too hard and is prone to cracking. ３ By setting the hardness within this range, the surface hardness of the sealing film became appropriate, but the flexibility of the film was still insufficient.

[0028] On the other hand, it is generally known that a low moisture content is preferable from the viewpoint of protecting an organic EL device. However, the effect of moisture content on the film surface properties is not known, and it has been found that a decrease in moisture content can sometimes result in a decrease in scratch resistance depending on the adhesion conditions when wound into a roll. As a result of extensive research, the present inventors have found that the density of 0.85 g / cm ３ or a density of 1.08 g / cm ３ If the moisture content is higher and is 100 mass ppm or less, the scratch resistance deteriorates or there is no effect of improving the scratch resistance. ３It was found that the scratch resistance improved dramatically when the moisture content was 100 ppm or less within this range. The reason for this is presumed to be as follows.

[0029] (a) When the density is high, the film surface hardness is high, and when the density is low, the film surface hardness is also low. (b) Film molecules are hydrogen-bonded via water. When the hydrogen bonds are strong, the flexibility of the film decreases. At low densities, the film surface hardness is originally low and it is prone to scratches, and when the hydrogen bonding strength is reduced by reducing the water content, the film becomes even more fragile. (c) At high densities, the film surface hardness is too high and it is prone to crack-like scratches. When the hydrogen bonding strength is reduced by reducing the water content, flexibility should be imparted, but the influence of film hardness is so strong that the flexibility effect is not realized. Therefore, when the density is 0.85 to 1.08 g / cm ３ In this case, it is presumed that the film maintains a moderate hardness and is given flexibility by reducing the hydrogen bonding strength due to the reduced water content, thereby realizing the effects of the present invention. Note that if the water content is too low, the film tends to become brittle, so the water content is preferably 5 ppm by mass or more.

[0030] <Occurrence of Image Defects> (Estimated Cause) Localized curing unevenness within the sealing film is thought to cause shrinkage in areas with low curing rates, resulting in fine wrinkles and image defects. Specifically, in the inkjet coating process, repeated discharge, interruption, and discharge lead to slight changes in droplet speed and direction. That is, latency is thought to cause uneven coating density, which may not affect thick films, but may lead to uneven curing in thin films, resulting in wrinkle defects. Furthermore, it is thought that this becomes more pronounced due to minute shrinkage of the sealing film over time. Here, "latency," also known as decap time, refers to the time during which droplet speed and direction remain unchanged and maintain an acceptable range of variation even when discharge is interrupted without a cap for a certain period of time. A commonly required latency is, for example, the time during which the droplet speed before and after a discharge interruption is limited to a change of approximately 10%.

[0031] (Countermeasures) In the present invention, it has been found that wrinkle defects can be reduced by strictly controlling the latency. Specifically, by setting the latency time at which the droplet velocity change is within 3% to 20 seconds or more, the curing rate of the coating film is uniform and wrinkle defects are suppressed. There is no particular upper limit to the latency as long as it is 20 seconds or more, but an interruption of 1,000 seconds or more is undesirable because it reduces productivity. Furthermore, it has been found that latency also tends to improve by reducing the density of the sealing composition. It is presumed that reducing the density of the sealing composition weakens the intermolecular forces, making it less likely for the liquid state to change due to compression in the narrow space inside the nozzle.

[0032] As described above, by setting the density and water content of the uncured sealing composition within the above ranges, hardness and flexibility are imparted to the surface of the sealing film, the occurrence of scratches can be prevented, and latency is improved, thereby reducing image defects.

[0033] The light transmittance vs. light wavelength peak curves for the sealing compositions of Examples 4 and 19 are obtained by normalizing the transmittance at a transmitted light wavelength of 650 nm in FIG. 1 to 100%.

[0034] The electronic device encapsulating composition for inkjet printing of the present invention is an electronic device encapsulating composition for inkjet printing containing a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer contains a (meth)acrylate, and the density of the uncured encapsulating composition at 25°C is 0.85 to 1.08 g / cm ３ and the water content measured by the Karl Fischer method is 100 ppm by mass or less. This feature is a technical feature common to or corresponding to each of the following embodiments.

[0035] In an embodiment of the present invention, it is preferable that the water content is 5 ppm by mass or more, since this can prevent a decrease in hydrogen bonding strength, and as a result, can prevent the film from becoming brittle and impart flexibility.

[0036] The sealing composition preferably has a latency of 20 seconds or more, at which the change in droplet velocity between before and after the interruption of inkjet ejection and the subsequent restart of ejection is ±3% or less, which makes the film curing rate uniform and suppresses wrinkle-like defects.

[0037] The density of the uncured sealing composition at 25°C is 0.94 to 1.05 g / cm ３ It is preferable that the thickness is within the range of 1000 nm, since this allows the film to maintain a suitable hardness and is effective in preventing the occurrence of scratches and wrinkle-like defects.

[0038] The total content of aluminum (Al), iron (Fe), and sodium (Na) contained in the sealing composition is preferably 1 mass ppm or less relative to the total amount of the sealing composition. This reduces the metal content in the sealing composition and prevents curing inhibition during curing by ultraviolet irradiation. In other words, the degree of molecular cross-linking is increased, which is effective in preventing the occurrence of scratches.

[0039] In all of the photopolymerizable monomers, the average number of oxygen atoms contained in one molecule is preferably 2.5 to 3.0, which allows the polarity of the molecules, i.e., the intermolecular force, to be controlled, the density to be reduced to within the range of the present invention, and the film to maintain an appropriate hardness.

[0040] When the spectral transmission spectrum of the sealing composition is measured, the vertical axis represents the light transmittance, the horizontal axis represents the transmitted light wavelength, and the transmittance at a transmitted light wavelength of 650 nm is normalized to 100% to obtain a light transmittance-light wavelength peak curve. In this case, the gradient of the tangent at a wavelength of 450 nm is preferably within a range of 2.5 to 5.0% / nm, from the viewpoint of hardness and flexibility of the film.

[0041] It is preferable that all of the photopolymerizable monomers contain 30% by mass or more of monomers having 3 or less double bonds in one molecule, which makes it possible to control the polarity of the molecules, i.e., the intermolecular force, to keep the density within the range of the present invention, and to maintain an appropriate hardness of the film.

[0042] The method for producing an electronic device encapsulating composition of the present invention includes a step of preparing a solution of the photopolymerizable monomer and the photopolymerization initiator, followed by a step of dehydrating the solution, which allows the water content in the encapsulating composition to be controlled and allows flexibility to be imparted to the film.

[0043] It is preferable to have a degassing step after the liquid preparation step, as this reduces dissolved oxygen and nitrogen, lowers the density to control it within the range of the present invention, and maintains an appropriate hardness of the film.

[0044] It is preferable to include a step of filtering the sealing composition with a metal removal filter after the solution preparation step, since this allows the metal in the sealing composition to be removed and makes it easier to adjust the density. Furthermore, by removing the metal from the sealing composition, the intermolecular force of the monomer is strengthened using the metal as a catalyst, and therefore, densification can be prevented.

[0045] The electronic device sealing film of the present invention is an electronic device sealing film for sealing an electronic device, and includes an inorganic protective layer containing silicon nitride, silicon oxide, or silicon oxynitride, and an organic protective layer using the electronic device sealing composition, thereby providing a sealing film that prevents image defects such as scratches and wrinkles.

[0046] The density of the organic protective layer at 25°C is 0.85 to 1.08 g / cm ３ This is preferable in that it is possible to maintain a suitable hardness of the film and is effective in preventing the occurrence of scratches and wrinkle-like defects.

[0047] The organic protective layer preferably contains at least a monomer having an average number of oxygen atoms per molecule of 2.5 to 3.0 or a monomer having 3 or less double bonds per molecule, which allows the polarity of the molecules, i.e., the intermolecular force, to be controlled, and the film can maintain an appropriate hardness by reducing the density.

[0048] The method for forming an electronic device encapsulating film of the present invention is a method for forming an encapsulating film using the electronic device encapsulating composition, and includes the steps of forming an inorganic protective layer on an electronic device by a vapor phase method and forming an organic protective layer on the inorganic protective layer by applying the electronic device encapsulating composition, thereby providing a encapsulating film that is free from image defects such as scratches and wrinkles.

[0049] It is preferable to include a step of forming a second inorganic protective layer containing silicon nitride, silicon oxide or silicon oxynitride on the organic protective layer by a vapor phase method, in terms of excellent sealing performance.

[0050] In the step of forming the organic protective layer, it is preferable to use an inkjet method, since this allows the layer to be formed with high precision.

[0051] The present invention, its components, and embodiments and modes for carrying out the present invention will be described below. In this application, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0052] [Outline of the inkjet electronic device encapsulating composition of the present invention] The inkjet electronic device encapsulating composition of the present invention is an inkjet electronic device encapsulating composition containing a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer contains a (meth)acrylate, and the density of the uncured encapsulating composition at 25°C is 0.85 to 1.08 g / cm ３ and the water content measured by the Karl Fischer method is 100 ppm by mass or less. Hereinafter, the inkjet electronic device sealing composition will also be simply referred to as the "sealing composition".

[0053] <Density> The density of the uncured sealing composition at 25°C is 0.85 to 1.08 g / cm ３ and is in the range of 0.94 to 1.05 g / cm ３ The term "uncured sealing composition" refers to a sealing composition that has not yet been cured after preparation, and is a sealing composition before being irradiated with ultraviolet light or the like.

[0054] The density of the uncured sealing composition is measured as follows: First, the prepared sealing composition is placed in a 10 ml volumetric flask. Then, the mass of the sealing composition is measured using a precision electronic balance with a minimum display of 0.001 g (1 mg), and the density at 25°C is calculated.

[0055] The density of the cured film (sealing film) obtained by curing the sealing composition at 25°C is 0.85 to 1.08 g / cm ３ The density of the cured film is measured as follows: First, the sealing composition is applied to a PET film to a thickness of about 50 to 100 μm. Then, the density is measured at 300 mW / cm. ２ The cumulative light intensity under these conditions is 1.5 J / cm ２ The coating film is cured by irradiating it with ultraviolet light having a wavelength of 395 nm (MZ 240 mm 395 nm UVLED manufactured by IST Corporation) so that the density becomes 100%. Thereafter, the coating is peeled off from the PET film, and the density of the cured film at 25°C is measured by the underwater displacement method described in JIS-K-7112.

[0056] Examples of methods for controlling the density of the uncured sealing composition and the cured film include the following (i) to (iii). (i) Adjusting the number of oxygen atoms and the number of double bonds in one molecule of the photopolymerizable monomer. It is presumed that the presence of oxygen atoms and double bonds increases the polarity of the molecule, strengthening the intermolecular forces and increasing the density. Therefore, for all photopolymerizable monomers, it is preferable that the average number of oxygen atoms in one molecule is 2.5 to 3.0. Furthermore, it is preferable that all photopolymerizable monomers contain 30% by mass or more of monomers with 3 or fewer double bonds in one molecule.

[0057] Here, "the average number of oxygen atoms contained in one molecule for all of the photopolymerizable monomers" is calculated as follows, for example, in the case of Formulation A in the Examples described later. (Photopolymerizable monomers of Formulation A) a-2: 1,10-decanediol diacrylate (number of oxygen atoms contained: 4) 25 parts by mass a-3: Triethylene glycol diacrylate (number of oxygen atoms contained: 6) 17 parts by mass a-4: Triethylene glycol dimethacrylate (number of oxygen atoms contained: 6) 17 parts by mass a-6: Ethoxylated-o-phenylphenol acrylate (number of oxygen atoms contained: 3) 41 parts by mass "The average number of oxygen atoms contained in one molecule for all of the photopolymerizable monomers" = 4 × 25 parts by mass + 6 × 17 parts by mass + 6 × 17 parts by mass + 3 × 41 parts by mass / 100

[0058] (ii) Degassing is performed to minimize dissolved oxygen and nitrogen in the sealing composition. It is believed that the presence of oxygen and nitrogen in the voids between the photopolymerizable monomers increases the density. Therefore, if air or nitrogen is bubbled during preparation of the sealing composition, it is preferable to degas the composition.

[0059] (iii) Reducing the metal content in the sealing composition. If metal is mixed into the sealing composition during the preparation or dehydration process of the sealing composition, it becomes difficult to adjust the density. It is presumed that the presence of metal in the sealing composition acts as a catalyst to improve the intermolecular forces of the monomers, thereby increasing the density. Therefore, in order to control the density of the sealing composition, the metal content is preferably 5 ppm by mass or less, but in order to reduce curing inhibition during UV curing, it is preferably 1 ppm by mass or less.

[0060] <Water Content> The sealing composition of the present invention has a water content of 100 ppm by mass or less, as measured by the Karl Fischer method. The water content is preferably within the range of 5 to 50 ppm by mass. The water content was measured using Aquamicron AX and Aquamicron CXU (manufactured by Mitsubishi Chemical Corporation) as Karl Fischer solutions, and a Karl Fischer trace moisture analyzer CA-200 (manufactured by Mitsubishi Chemical Analytech Co., Ltd.). The measurement environment was a dry room at 20°C with a dew point of -30°C or less. One example of a means for controlling the water content is distillation during preparation of the sealing composition. Since prolonged distillation at high temperatures can cause coloration in some sealing compositions, it is preferable to distill at the lowest possible temperature for the shortest possible time using vacuum distillation or thin-film distillation. It is also recommended to avoid dehydration treatment using fillers such as molecular sieves, as this increases the metal content in the sealing composition, making it difficult to remove with a filter and making it difficult to adjust the density of the composition.

[0061] <Latency> The sealing composition of the present invention preferably has a latency of 20 seconds or more, which is the time when inkjet ejection is interrupted and then resumed, during which the change in droplet velocity between before and after the interruption of ejection is ±3% or less. In the present invention, "latency" is also referred to as the ink decap time. The decap time is the time during which droplets can be ejected properly, i.e., without misdirection, loss of color, or excessive slowdown, even when the print head is left uncapped and unused. Decap is sometimes referred to as "latency" in the art, and the two terms are used interchangeably.

[0062] The latency is measured as follows: The sealing composition is placed in an inkjet printer cartridge, maintained at 25°C, and droplets of the sealing composition are ejected from the nozzle of the inkjet printer. After that, the ejection is suspended for a certain period of time without capping, and then droplets of the sealing composition are ejected again. The ejection state is photographed with a high-speed camera, and the time from when the droplets are ejected from the nozzle to when they land on the substrate is measured. The distance from the nozzle to the substrate is also measured. Then, the change in ejection velocity before and after the interruption is calculated from the time to impact and the distance. The interruption time is changed to 5 seconds, 10 seconds, 15 seconds, 30 seconds, 50 seconds, 75 seconds, 100 seconds, 300 seconds, 500 seconds, 750 seconds, and 1000 seconds. The change in the time from ejection to impact before and after the interruption, i.e., the maximum interruption time at which the droplet velocity changes by 3% or less, is defined as the latency.

[0063] In order to set the latency at which the droplet change rate is 3% or less to 20 seconds or more, it is preferable to lower the density of the sealing composition. In particular, as described above, it is effective to reduce the metal content in the sealing composition.

[0064] <Total Content of Aluminum, Iron, and Sodium> The total content of aluminum (Al), iron (Fe), and sodium (Na) contained in the sealing composition of the present invention is preferably 1 mass ppm or less relative to the total amount of the sealing composition. Furthermore, while zero is ideal in principle, the lower limit of this total content is 0.5 mass ppm for measurement accuracy. By keeping the total content of metal elements in the sealing composition within the above range, the density of the sealing composition can be reduced. Furthermore, by keeping the total content within the above range, the curing inhibition of a coating film made of the sealing composition during ultraviolet irradiation can be prevented. The content of Al, Fe, and Na can be measured using a CP optical emission spectrometer SPS3520UV (Hitachi).

[0065] As a means for keeping the total content of each metal element within the above range, for example, metals can be removed using a metal ion removal filter. Since metals are mixed in through various operations, it is preferable to filter after operations such as liquid preparation and dehydration are completed. As mentioned above, if a filler such as a molecular sieve is used, it becomes difficult to remove metals even with a metal ion removal filter, so it is preferable not to use it.

[0066] <Slope of Spectral Transmission Spectrum> When the spectral transmission spectrum of a sealing composition is measured, the vertical axis represents light transmittance, the horizontal axis represents transmitted light wavelength, and the horizontal axis represents the transmittance at a transmitted light wavelength of 650 nm is normalized to 100%. In the light transmittance-light wavelength peak curve obtained by normalizing the transmittance at a transmitted light wavelength of 650 nm, the slope of the tangent at a wavelength of 450 nm is preferably within the range of 2.5 to 5.0% / nm. Setting the slope of the tangent at a wavelength of 450 nm within the above range is preferable from the viewpoints of both the hardness and flexibility of the sealing film, and can suppress scratches. Here, if the slope of the tangent is steep, the UV absorption rate at 450 to 500 nm required for curing is low, and uneven curing occurs, particularly in thin films, making wrinkle-like defects more likely to occur. On the other hand, if the slope is gentle, absorption of the above wavelengths is sufficient, but the short curing time, particularly in thin films, makes uneven UV absorption more likely to occur. This causes uneven curing, resulting in uneven hardness of the sealing film surface and insufficient scratch resistance.

[0067] The spectral transmittance spectrum of the sealing composition was measured using a V650 spectrophotometer (manufactured by JASCO Corporation). The spectrum was then normalized so that the transmittance at 650 nm was 100%. A tangent was then drawn at 450 nm to the normalized spectral curve, and the slope of the tangent was determined. For example, FIG. 1 shows the light transmission spectra of sealing composition 5 of Example 4 and sealing composition 25 of Example 19, which will be described later. The vertical axis represents light transmittance, and the horizontal axis represents the transmitted light wavelength. FIG. 2 shows a light transmittance-light wavelength peak curve obtained by normalizing the transmittance at 650 nm of FIG. 1 to 100%. A tangent was drawn at a wavelength of 450 nm to each of the curves in FIG. 2, and the slope of the tangent was determined. In the case of Example 4, the slope of the tangent was 5.0, and in the case of Example 19, the slope of the tangent was 3.0.

[0068] [Composition of the Encapsulating Composition] The electronic device encapsulating composition of the present invention contains a photopolymerizable monomer and a photopolymerization initiator. The photopolymerizable monomer according to the present invention contains a (meth)acrylate. In this specification, "(meth)acrylate" refers to at least one of acrylate and methacrylate. Hereinafter, the "electronic device encapsulating composition" will also be simply referred to as the "encapsulating composition." Furthermore, the "electronic device" in the present invention refers to an element that generates, amplifies, converts, or controls an electrical signal by utilizing the kinetic energy, potential energy, or the like of electrons. Examples of such elements include active elements such as light-emitting diode elements, organic electroluminescence elements, photoelectric conversion elements, and transistors. Furthermore, in the present invention, passive elements that perform passive tasks such as "resisting" or "storing" external forces, such as resistors and capacitors, are also included in the electronic device. Therefore, the encapsulating composition of the present invention is used to form an encapsulating film for encapsulating the above-mentioned electronic device.

[0069] <Photopolymerizable Monomer> A "photopolymerizable monomer" refers to a photopolymerizable monomer that can undergo a polymerization (curing) reaction by absorbing light itself or a photopolymerization initiator to generate active ions or radicals. Such a photopolymerizable monomer is also referred to as a "photocurable monomer." As described above, the composition for sealing an electronic device of the present invention contains a (meth)acrylate as the photopolymerizable monomer. Note that a non-silicon monomer that does not contain silicon (Si) may also be used as the photopolymerizable monomer. The photopolymerizable monomer may be, for example, a monomer consisting only of an element selected from C, H, O, N, or S, but is not limited thereto. The photopolymerizable monomer may be synthesized by a conventional synthesis method and used, or a commercially available product may be purchased and used.

[0070] Examples of the photopolymerizable monomer include the following photopolymerizable monomer (A) having no aromatic hydrocarbon group and photopolymerizable monomer (B) having an aromatic hydrocarbon group. In the present invention, these photopolymerizable monomers are appropriately selected so that the density and moisture content of the uncured encapsulating composition satisfy the above-mentioned ranges. For example, as described above, it is preferable to select all of the photopolymerizable monomers so that the average number of oxygen atoms contained per molecule is 2.5 to 3.0. It is also preferable that all of the photopolymerizable monomers contain 30% by mass or more of monomers having 3 or less double bonds per molecule. Note that preferred combinations of photopolymerizable monomers in the present invention are as described in the Examples below.

[0071] <Photopolymerizable Monomer (A) Having No Aromatic Hydrocarbon Group> The photopolymerizable monomer (A) having no aromatic hydrocarbon group does not contain an aromatic hydrocarbon group. The photopolymerizable monomer (A) having no aromatic hydrocarbon group may contain 1 to 20 photocurable functional groups (photopolymerizable functional groups) selected from the group consisting of vinyl groups, acrylic groups, and methacrylic groups. Specifically, the photopolymerizable monomer (A) may have 1 to 6 photocurable functional groups, for example, 1 to 3, 1 to 2, 1, or 2 photocurable functional groups. Hereinafter, the photopolymerizable monomer (A) having no aromatic hydrocarbon group will also be referred to simply as "photopolymerizable monomer (A)."

[0072] 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. The weight average molecular weight may be in the range of 130 to 400 g / mol, or in the range of 200 to 300 g / mol. By setting the weight average molecular weight of the monomer within this range, more advantageous effects can be achieved in terms of the process.

[0073] The photopolymerizable monomer (A) may include a monofunctional monomer having a photocurable functional group, a polyfunctional monomer, or a mixture thereof.

[0074] Specifically, the photopolymerizable monomer (A) may be a (meth)acrylate monomer, and may be an unsaturated carboxylic acid ester having an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a hydroxy group and an alkyl group having 1 to 20 carbon atoms, an unsaturated carboxylic acid ester having an aminoalkyl group having 1 to 20 carbon atoms, a vinyl ester of a saturated or unsaturated carboxylic acid having 1 to 20 carbon atoms, a vinyl cyanide compound, an unsaturated amide compound, a monofunctional or polyfunctional (meth)acrylate of a monoalcohol or a polyhydric alcohol, etc. The "polyhydric alcohol" refers to an alcohol having two or more hydroxy groups, and more preferably an alcohol having 2 to 20 hydroxy groups, preferably 2 to 10 hydroxy groups, and more preferably 2 to 6 hydroxy groups.

[0075] Among the photopolymerizable monomers (A), the (meth)acrylate monomers having no aromatic hydrocarbon group may be, for example, mono(meth)acrylates, di(meth)acrylates, tri(meth)acrylates, tetra(meth)acrylates, etc. having a substituted or unsubstituted C1 to C20 (carbon number 1 to 20) alkyl group, a substituted or unsubstituted C1 to C20 (carbon number 1 to 20) alkylsilyl group, a substituted or unsubstituted C3 to C20 (carbon number 3 to 20) cycloalkyl group, a substituted or unsubstituted C1 to C20 (carbon number 1 to 20) alkylene group, an amine group, an ethylene oxide group, or the like.

[0076] Specifically, the (meth)acrylate monomer having no aromatic hydrocarbon group includes unsaturated carboxylic acid esters including (meth)acrylic acid esters 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, decanyl (meth)acrylate, undecanyl (meth)acrylate, dodecyl (meth)acrylate, and cyclohexyl (meth)acrylate; unsaturated carboxylic acid aminoalkyl esters such as 2-aminoethyl (meth)acrylate and 2-dimethylaminoethyl (meth)acrylate; saturated or unsaturated carboxylic acid vinyl esters such as vinyl acetate; cyanide vinyl compounds such as (meth)acrylonitrile; unsaturated amide compounds such as (meth)acrylamide; ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and the like. ethylene glycol di(meth)acrylate, trimethylolpropane 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 di(meth)acrylate, neopentyl glycol di(meth)acrylate, penta The acrylates may include, but are not limited to, erythritol 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 mixtures thereof.

[0077] In one example of the present invention, the photopolymerizable monomer (A) is a non-aromatic monomer that does not contain an aromatic group, and may include at least one of a mono(meth)acrylate having an alkyl group having 1 to 20 carbon atoms, a mono(meth)acrylate having an amine group, a di(meth)acrylate having a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a di(meth)acrylate having an ethylene oxide group, a tri(meth)acrylate having an ethylene oxide group, and a mono(meth)acrylate and di(meth)acrylate having a cyclic carbonized alkyl group.

[0078] Specific examples of the mono(meth)acrylate having a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms include, but are not limited to, isostearyl (meth)acrylate, isodecyl (meth)acrylate, 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, arachidyl (meth)acrylate, or mixtures thereof.

[0079] The mono(meth)acrylate having an amine group may be, but is not limited to, 2-aminoethyl(meth)acrylate, 2-dimethylaminoethyl(meth)acrylate, or a mixture thereof.

[0080] The di(meth)acrylate having a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms may be, for example, a di(meth)acrylate having an alkylene group having 1 to 20 carbon atoms. Furthermore, the di(meth)acrylate having a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms may be 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 having 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 di(meth)acrylate, or a mixture thereof, but is not limited thereto. When the sealing composition of the present invention contains the (meth)acrylate having a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, the photocuring rate of the sealing composition of the present invention can be further improved and the viscosity can be reduced.

[0081] The di(meth)acrylate or tri(meth)acrylate having an ethylene oxide group may specifically be, but is not limited to, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, or a mixture thereof.

[0082] The mono(meth)acrylate and di(meth)acrylate having a cyclic carbonized alkyl group may specifically be isobornyl(meth)acrylate or tricyclodecane dimethanol di(meth)acrylate. The mono(meth)acrylate and di(meth)acrylate having a cyclic carbonized alkyl group may specifically be dicyclopentanyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, dicyclopentenyl(meth)acrylate or dicyclopentanyl(meth)acrylate.

[0083] The photopolymerizable monomer (A) is preferably contained in an amount of 55 to 95 mass % relative to the total mass of the photopolymerizable monomers (photopolymerizable monomer (A) and photopolymerizable monomer (B)), and more preferably contained in an amount of 60 to 90 mass %.

[0084] <Photopolymerizable Monomer (B) Having an Aromatic Hydrocarbon Group> The photopolymerizable monomer (B) having an aromatic hydrocarbon group contains two or more phenyl groups and a heteroatom, and has a structure represented by the following general formula (1), and the photopolymerizable monomer (B) contains at least a mono(meth)acrylate or a di(meth)acrylate. Hereinafter, the photopolymerizable monomer (B) having an aromatic hydrocarbon group will also be simply referred to as "photopolymerizable monomer (B)."

[0085]

[0086] In the general formula (1), P represents a substituted or unsubstituted hydrocarbon group containing two or more phenyl groups, or a substituted or unsubstituted heteroatom-containing hydrocarbon group containing two or more phenyl groups. １ and Z ２ each independently has a structure represented by the following general formula (2), where a and b are each an integer of 0 to 2, and a+b is an integer of 1 to 4.

[0087]

[0088] In the general formula (2), * represents a linking point 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. R １ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and c is an integer of 0 or 1.

[0089] In the general formula (1), P represents a substituted or unsubstituted hydrocarbon group containing two or more phenyl groups, or a substituted or unsubstituted heteroatom-containing hydrocarbon group containing two or more phenyl groups. The substituted or unsubstituted hydrocarbon group containing two or more phenyl groups, or the substituted or unsubstituted heteroatom-containing hydrocarbon group containing two or more phenyl groups, means that two or more substituted or unsubstituted phenyl groups are not condensed together, but are linked by 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.

[0090] For example, the hydrocarbon group containing two or more phenyl groups or the heteroatom-containing hydrocarbon group containing two or more phenyl groups may include, but are not limited to, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted triphenylmethyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted quaterphenylene group, a substituted or unsubstituted 2-phenyl-2-(phenylthio)ethyl group, a substituted or unsubstituted 2,2-diphenylpropane group, a substituted or unsubstituted diphenylmethane group, a substituted or unsubstituted cumylphenyl group, a substituted or unsubstituted bisphenol F group, a substituted or unsubstituted bisphenol A group, a substituted or unsubstituted biphenyloxy group, a substituted or unsubstituted terphenyloxy group, a substituted or unsubstituted quaterphenyloxy group, a substituted or unsubstituted quinquiphenyloxy group, and structural isomers thereof.

[0091] The substituted or unsubstituted monomer having two or more phenyl groups may be a mono(meth)acrylate, a di(meth)acrylate, or a mixture thereof, and examples thereof include 4-(meth)acryloxy-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, and ethoxylated bisphenol F di(meth)acrylate. ester, ethoxylated o-phenylphenol acrylate, 4-cumylphenoxyethyl 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-phenyl (triphenylmethyloxy)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- The acryloyloxymethyl (meth)acrylate may include, but is not limited to, 4,4'-di(acryloyloxymethyl)biphenyl, 2,2'-di(2-acryloyloxyethoxy)biphenyl, structural isomers thereof, or mixtures thereof.Furthermore, the (meth)acrylates mentioned in the present invention are merely examples and are not intended to be limiting. Furthermore, the present invention includes all acrylates that are structural isomers. For example, even if only 2,2'-phenylphenoxyethyl di(meth)acrylate is mentioned as an example of the present invention, the present invention includes all structural isomers. Examples of such structural isomers include 3,2'-phenylphenoxyethyl di(meth)acrylate and 3,3'-phenylphenoxyethyl di(meth)acrylate.

[0092] In one example 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).

[0093]

[0094] In the general formula (4), R ２ represents hydrogen or a methyl group. ３ 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. ４ represents a substituted or unsubstituted hydrocarbon group containing two or more phenyl groups, or a substituted or unsubstituted heteroatom-containing hydrocarbon group containing two or more phenyl groups.

[0095] For example, the above-mentioned substituted or unsubstituted hydrocarbon group containing two or more phenyl groups, or the substituted or unsubstituted heteroatom-containing hydrocarbon group containing two or more phenyl groups means that two or more substituted or unsubstituted phenyl groups are not condensed together, 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, an ethenylene group, an ethynylene group, or a carbonyl group. For example, the substituted or unsubstituted hydrocarbon group containing two or more phenyl groups or the substituted or unsubstituted heteroatom-containing hydrocarbon group containing two or more phenyl groups may include, but are not limited to, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted triphenylmethyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted quaterphenylene group, a substituted or unsubstituted 2-phenyl-2-(phenylthio)ethyl group, a substituted or unsubstituted 2,2-diphenylpropane group, a substituted or unsubstituted diphenylmethane group, a substituted or unsubstituted cumylphenyl group, a substituted or unsubstituted bisphenol F group, a substituted or unsubstituted bisphenol A group, a substituted or unsubstituted biphenyloxy group, a substituted or unsubstituted terphenyloxy group, a substituted or unsubstituted quaterphenyloxy group, a substituted or unsubstituted quinquiphenyloxy group, and the like.

[0096] In one example 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).

[0097]

[0098] In the general formula (5), R ５ and R ９ R each independently represents a hydrogen atom or a methyl group. ６ and R ８ R each independently 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. ７represents a substituted or unsubstituted hydrocarbon group containing two or more phenyl groups, or a substituted or unsubstituted heteroatom-containing hydrocarbon group containing two or more phenyl groups.

[0099] For example, the substituted or unsubstituted hydrocarbon group containing two or more phenyl groups or the substituted or unsubstituted heteroatom-containing hydrocarbon group containing two or more phenyl groups means that two or more substituted or unsubstituted phenyl groups are not condensed but are connected 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 hydrocarbon group may include, but is not limited to, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted triphenylmethylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted quaterphenylene group, a 2-phenyl-2-(phenylthio)ethylene group, a 2,2-diphenylpropylene group, a diphenylmethylene group, etc.

[0100] In the general formula (1), a and b each represent an integer of 0 to 2, and a+b represents an integer of 1 to 4, and in one example, a+b represents an integer of 1 or 2.

[0101] The weight-average molecular weight of the substituted or unsubstituted monomer having two or more phenyl groups is preferably within the range of 100 to 1,000 g / mol, more preferably within the range of 130 to 700 g / mol, and particularly preferably within the range of 150 to 600 g / mol. By setting the weight-average molecular weight within the above range, a sealing film with superior transmittance can be provided.

[0102] The photopolymerizable monomer (B) having an aromatic hydrocarbon group is preferably contained in an amount within a range of 5 to 45% by mass with respect to the total mass of the photopolymerizable monomers (photopolymerizable monomer (A) and photopolymerizable monomer (B)). The photopolymerizable monomer (B) is more preferably contained in an amount within a range of 10 to 40% by mass with respect to the total mass. By keeping the amount within this range, the viscosity becomes appropriate for forming a sealing film.

[0103] <Photopolymerization initiator> The photopolymerization initiator is not particularly limited as long as it is a common photopolymerization initiator that can cause a photocuring reaction. Examples of the photopolymerization initiator include triazine-based, acetophenone-based, benzophenone-based, thioxanthone-based, benzoin-based, phosphorus-based, oxime-based, and mixtures thereof.

[0104] Examples of triazine initiators include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, and 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine. , 2-biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl(piperonyl)-6-triazine, 2,4-(trichloromethyl(4'-methoxystyryl)-6-triazine, or a mixture thereof.

[0105] The acetophenone 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-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, and mixtures thereof.

[0106] The benzophenone 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 mixtures thereof.

[0107] The thioxanthone initiator may be thioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, or a mixture thereof. Commercially available thioxanthone initiators include 2-isopropylthioxanthone (Speedcure 2-ITX (manufactured by Sartomer) (molecular weight: 254)) and 2,4-diethylthioxanthone (Speedcure DETX (manufactured by Sartomer) (molecular weight: 268)).

[0108] The benzoin initiator may be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzil dimethyl ketal, or mixtures thereof.

[0109] The phosphorus-based initiator may be bisbenzoylphenylphosphine oxide, benzoyldiphenylphosphine oxide, or a mixture thereof. Commercially available examples of the phosphorus-based initiator include Omnirad TPO H (manufactured by IGM) (molecular weight: 348) and Omnirad 819 (manufactured by IGM) (molecular weight: 419) (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide).

[0110] The oximes may 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 mixtures thereof.

[0111] The photopolymerization initiator is preferably contained in the encapsulating composition of the present invention in a range of approximately 0.1 to 20 parts by mass, relative to 100 parts by mass of the total of the photopolymerizable monomer and the photopolymerization initiator. By containing the photopolymerization initiator in this range, sufficient photopolymerization occurs during exposure, and a decrease in transmittance due to remaining unreacted initiator after photopolymerization can be prevented. Specifically, the 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. Furthermore, the photopolymerization initiator is preferably contained in the encapsulating composition of the present invention in a range of 0.1 to 10% by mass, more preferably in a range of 0.1 to 5% by mass, based on the solids content. By containing the photopolymerization initiator in this range, sufficient photopolymerization occurs, and a decrease in transmittance due to remaining unreacted initiator can be prevented.

[0112] Instead of the photopolymerization initiator, a photoacid generator or photopolymerization initiator such as a carbazole type, a diketone, a sulfonium type, an iodonium type, a diazo type, or a biimidazole type may be used.

[0113] <Other Additives> The encapsulating composition of the present invention may further contain other components, including an antioxidant, a heat stabilizer, a photosensitizer, a dispersant, a thermal crosslinking agent, a surfactant, and a polymerization inhibitor, as long as the effects of the present invention are obtained. Only one of these components may be contained in the encapsulating composition of the present invention, or two or more types may be contained.

[0114] The antioxidant can improve the thermal stability of the sealing layer. The antioxidant may include, but is not limited to, one or more antioxidants selected from the group consisting of phenols, quinones, amines, and phosphites. Examples of antioxidants include tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane and tris(2,4-di-tert-butylphenyl)phosphite. Commercially available hindered phenol antioxidants include Adekastab AO-50 (manufactured by ADEKA Corporation), Adekastab AO-20 (manufactured by ADEKA Corporation), KEMINOX 9425 (manufactured by Chemipro Chemicals), KEMINOX 179 (manufactured by Chemipro Chemicals), Irganox 1076 (manufactured by BASF Japan), and Irganox 1010 (manufactured by BASF Japan).

[0115] The antioxidant is preferably contained in the sealing composition in a range of 0.01 to 3 parts by mass relative to a total of 100 parts by mass of the photopolymerizable monomer and the photopolymerization initiator. The antioxidant is more preferably contained in a range of 0.01 to 1 part by mass relative to the total of 100 parts by mass. By containing the antioxidant in this range, excellent thermal stability can be exhibited.

[0116] The heat stabilizer is contained in the sealing composition and serves to suppress a change in viscosity of the sealing composition at room temperature, and any conventional heat stabilizer can be used without limitation. For example, a sterically hindered phenolic heat stabilizer may be used as the heat stabilizer. Specific examples of the heat stabilizer 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'-methano-bi(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 ...'-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6'-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6'-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6'-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6'-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6'-di- The hydroxyphenyl)-N,N'-hexamethylene-dipropionamide, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), stearyl-3,5-di-tert-butyl-4-hydroxyphenylpropionate, pentaerythritol tetrakis-1,3,5-tris(2,6-di-methyl-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-butylhydroxyphenylpropionate), but is not limited thereto.

[0117] The heat stabilizer is preferably contained in the sealing composition in an amount of 2000 ppm or less based on the total of the photopolymerizable monomer and the photopolymerization initiator, based on the solid content. The heat stabilizer is preferably contained in a range of 0.01 to 2000 ppm, more preferably in a range of 100 to 1000 ppm, based on the total. By setting the heat stabilizer within the above range, the storage stability and processability of the sealing composition in a liquid state can be further improved.

[0118] The photosensitizer has the function of transferring absorbed light energy to the photopolymerization initiator, and therefore is a compound that can impart the original photopolymerization initiator function to the photopolymerization initiator used, even if the photosensitizer does not absorb light corresponding to the light from the light source. Examples of photosensitizers include 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 derivatives such as benzophenone, o-benzoylbenzoic acid methyl, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemethanaminium bromide, and (4-benzoylbenzyl)trimethylammonium chloride; Examples of the photosensitizer include thioxanthone derivatives such as 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthone-9-one mesochloride. As the photosensitizer, it is particularly preferable to use an anthracene derivative, a benzoin derivative, a benzophenone derivative, an anthraquinone derivative, or a thioxanthone derivative.

[0119] The surfactant can improve the ejection stability of the ink and control the spread (dot diameter) of ink droplets that have landed on a recording medium. When an anionic compound is included as a constituent of the ink, the surfactant may be anionic, nonionic (also called "nonionic"), or amphoteric. The amphoteric surfactant is preferably a betaine type.

[0120] The surfactant is preferably a fluorine-based or silicone-based surfactant having a high static surface tension reducing ability, an anionic surfactant such as dioctyl sulfosuccinate having a high dynamic surface tension reducing ability, or a nonionic surfactant such as a relatively low molecular weight polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, acetylene glycol, Pluronic (registered trademark) surfactant, sorbitan derivative, etc. Note that a surfactant having a high static surface tension reducing ability and a surfactant having a high dynamic surface tension reducing ability may be used in combination.

[0121] In the present invention, it is preferable to use, as the surfactant, for example, BYK-3760 (manufactured by BYK Corporation, polyether-modified polydimethylsiloxane), BYK-UV3500 (manufactured by BYK Corporation, polyether-modified polydimethylsiloxane having an acrylic group), BYK-UV3530 (manufactured by BYK Corporation, polyether-modified siloxane having an acrylic group), KL-100 (manufactured by Kyoeisha Chemical Co., Ltd., polyether-modified polysiloxane + amphiphilic oligomer), KL-401 (manufactured by Kyoeisha Chemical Co., Ltd., polyether-modified polysiloxane), TSF-4452 (manufactured by Momentive Corporation, polyether-modified silicone oil), BYK-3560 (manufactured by BYK Corporation, polyether macromer-modified), BYK-3565 (manufactured by BYK Corporation, polyether silicone macromer-modified), etc.

[0122] The polymerization inhibitor can reduce the adhesiveness between multiple curable compounds. In the present invention, the term "polymerization inhibitor" includes all compounds added to inhibit polymerization reactions during the preparation of a sealing composition containing a polymerizable compound or during storage after preparation. In the present invention, various conventionally known polymerization inhibitors can be used. As the polymerization inhibitor, it is preferable to contain any of an N-oxyl-based polymerization inhibitor, a phenol-based polymerization inhibitor containing an o-t-butyl group, or a polymerization inhibitor having two or more aromatic rings. In particular, it is preferable to use an N-oxyl-based polymerization inhibitor.

[0123] Examples of the N-oxyl polymerization inhibitor include 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-methoxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-acetoxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, Irgastab (registered trademark) UV10 (manufactured by BASF), and sebacate bis(2,2,6,6-tetramethyl-4-piperidyl-1-oxyl).

[0124] <Ultraviolet Curing> The ultraviolet light used to irradiate the sealing composition of the present invention for curing can be any known means, and is not particularly limited as long as the curing occurs by irradiation with ultraviolet light in the range of 200 to 400 nm. Preferably, a 395 nm LED is used as the ultraviolet light, from the viewpoint of preventing deterioration of the electronic device. The environment in which the ultraviolet light is irradiated can be any known means, and is not particularly limited as long as the sealing composition is cured by irradiation with ultraviolet light. Preferably, from the viewpoint of preventing deterioration of the electronic device and preventing the influence of oxygen in inhibiting curing, the ultraviolet light is irradiated in an inert gas environment. In particular, irradiation in a nitrogen or argon gas atmosphere is preferred.

[0125] <Physical Properties> The viscosity of the sealing composition of the present invention is preferably within a range of 3 to 30 mPa·s from the viewpoint of further improving the ejectability from an inkjet head, and the surface tension is preferably 15 mN / m or more and less than 45 mN / m from the viewpoint of further improving the ejectability from an inkjet head.

[0126] The viscosity of the sealing composition of the present invention can be determined by measuring the temperature change of the dynamic viscoelasticity of the sealing composition using, for example, various rheometers. In the present invention, these viscosities are values ​​obtained by the following method. The sealing composition of the present invention is set in a stress-controlled rheometer, Physica MCR300 (cone plate diameter: 75 mm, cone angle: 1.0°) manufactured by Anton Paar. Next, the sealing composition is heated to 100°C and cooled to 20°C under the conditions of a temperature decrease rate of 0.1°C / s, a strain of 5%, and an angular frequency of 10 radian / s, to obtain a temperature change curve of the dynamic viscoelasticity.

[0127] The sealing composition of the present invention may contain pigment particles. From the viewpoint of further improving the ejection properties from an inkjet head, the average particle size of the pigment particles when the sealing composition of the present invention contains a pigment is preferably within the range of 0.08 to 0.5 μm. Furthermore, the maximum particle size of the pigment particles is preferably within the range of 0.3 to 10 μm. The average particle size of the pigment particles in the present invention refers to a value determined by dynamic light scattering using a Datasizer Nano ZSP (manufactured by Malvern). Note that sealing compositions containing colorants have a high concentration, and light does not pass through this measuring instrument. Therefore, the sealing composition is diluted 200 times before measurement. The measurement temperature is room temperature (25°C).

[0128] The sealing composition of the present invention preferably has an Ohnesorge number (Oh) expressed by the following formula 1, calculated by the density ρ, the surface tension σ of the sealing composition, the viscosity μ of the sealing composition, and the nozzle diameter D0, in the range of 0.1 to 1. When the Ohnesorge number (Oh) is in the above range, the inkjet ejection properties and the ink droplet stabilization during flight are excellent.

[0129]

[0130] It is preferable to prepare the encapsulating composition of the present invention and provide a cured polymer having a Tg (glass transition temperature) 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 viewpoint of ensuring stability in the formation process of electronic devices, driving temperatures, and reliability tests.

[0131] [Method for producing a composition for encapsulating an electronic device] The method for producing a composition for encapsulating an electronic device of the present invention includes a step of preparing a solution of a photopolymerizable monomer and a photopolymerization initiator, followed by dehydration. The method preferably includes a degassing step after the solution preparation step. The method preferably includes a filtration step using a metal removal filter after the solution preparation step. After the solution preparation step, the dehydration step, degassing step, and filtration steps may be performed in any order, but the order of the solution preparation step, dehydration step, degassing step, and filtration steps is particularly preferred. Finally, a dehydration step may be added again, and the number of times each step is performed is not important. Hereinafter, each of the above steps will be described as the production method of the present invention.

[0132] In the liquid preparation step, the photopolymerizable monomer, the photopolymerization initiator, and other additives, if necessary, are mixed in a predetermined ratio and dissolved by stirring while heating. The heating temperature is preferably within a range of 50 to 80°C.

[0133] <Dehydration Step> In the dehydration step, the prepared solution is dehydrated. Dehydration allows the water content in the sealing composition to be adjusted, thereby improving the flexibility of the film. Distillation or molecular sieves can be used as a dehydration method, but in the present invention, distillation is preferred because it allows for a reduction in the metal content in the composition. As a result, it becomes easier to adjust the density of the sealing composition. Furthermore, since prolonged distillation at high temperatures can cause coloration in some sealing compositions, it is preferable to perform distillation at as low a temperature and as short a time as possible using vacuum distillation or thin-film distillation. The distillation temperature is preferably in the range of 60 to 80°C. The distillation time is preferably in the range of 1 to 30 hours. In vacuum distillation, it is preferable to perform the distillation under a pressure of 0.1 to 20 KPa. Furthermore, it is preferable to perform the distillation while bubbling with nitrogen or dry air.

[0134] <Degassing step> In the degassing step, the solution after preparation may be dehydrated, but it is particularly preferable to degas the solution after dehydration. Degassing is preferable because it can remove oxygen and nitrogen present in the gaps between the monomers and reduce the density of the sealing composition. In particular, degassing is preferable when bubbling with air, nitrogen, or the like is performed in the dehydration step, etc. Degassing methods using, for example, a hollow fiber membrane, vacuum, or ultrasonic waves are preferred.

[0135] When hollow fiber membranes are used, it is preferable to degas using a degassing module while reducing the pressure. The hollow fiber degassing module may be either an external reflux type or an internal reflux type. From the viewpoint of favorable degassing efficiency and processing flow rate, the external reflux type is preferred. As a commercially available hollow fiber degassing module, for example, "SEPAREL PF-001D" (manufactured by DIC Corporation) can be used.

[0136] When ultrasonic waves are used, for example, an ultrasonic vibrator that generates ultrasonic waves is provided in a degassing tank. Then, the ultrasonic vibrator is driven with the sealing composition placed in the tank, thereby irradiating the sealing composition with ultrasonic waves. The ultrasonic vibrator may be provided inside the degassing tank to directly irradiate the sealing composition. Alternatively, the ultrasonic vibrator may be provided outside the degassing tank to indirectly irradiate the sealing composition through the wall of the tank or other liquid.

[0137] When a sealing composition is irradiated with ultrasonic waves, the sealing composition vibrates, causing so-called cavitation, in which gas dissolved in the sealing composition gathers and precipitates as bubbles. The bubbles precipitated by cavitation rise to the surface of the sealing composition and leave the sealing composition, reducing the amount of gas dissolved in the sealing composition.

[0138] The oscillation frequency and irradiation energy of the ultrasonic waves can be appropriately set depending on the composition, viscosity, etc. of the sealing composition. Furthermore, it is preferable to create a vacuum in addition to the ultrasonic waves, since this allows for efficient degassing. Specifically, a vacuum pump is connected to a tank or container containing the sealing composition, and a vacuum of 1.5 kPa or less is created, causing air bubbles to rise to the surface and be expelled from the sealing composition.

[0139] <Step of filtering through a metal removal filter> In the step of filtering through a metal removal filter, the prepared solution may be filtered through a metal removal filter to remove metals, but it is particularly preferable to filter the solution after degassing. Filtration may be performed multiple times. It is also preferable to reduce or increase pressure so that the solution passes through the metal removal filter. Examples of commercially available metal removal filters include "IR-DA47-SCPD (manufactured by 3M)" and "MIR-DA47-APP (manufactured by 3M)." It is preferable to use multiple types of filters that remove different metals in combination. Note that "IR-DA47-SCPD (manufactured by 3M)" can remove Na, and "MIR-DA47-APP (manufactured by 3M)" can remove Al and Fe.

[0140] [Electronic Device Sealing Film Forming Method] The electronic device sealing film forming method of the present invention is a method for forming a sealing film using the electronic device sealing composition of the present invention described above, and includes the steps of forming an inorganic protective layer (first sealing layer) on an electronic device by a vapor phase method, and forming an organic protective layer (second sealing layer) by applying the electronic device sealing composition on the inorganic protective layer. Furthermore, it is preferable to include the step of forming a second inorganic protective layer (third sealing layer) containing silicon nitride, silicon oxide, or silicon oxynitride on the organic protective layer by a vapor phase method, in order to further improve the sealing performance of the electronic device. Hereinafter, the inorganic protective layer will also be referred to as the "first sealing layer," the organic protective layer will also be referred to as the "second sealing layer," and the second inorganic protective layer on the organic protective layer will also be referred to as the "third sealing layer."

[0141] <First sealing layer forming step> In the first sealing layer forming step, a first sealing layer is formed on an electronic device by a gas phase method. Examples of the gas phase method include sputtering (e.g., magnetron cathode sputtering, planar magnetron sputtering, bipolar AC planar magnetron sputtering, bipolar AC rotating magnetron sputtering, and other reactive sputtering methods), vapor deposition (e.g., resistance heating vapor deposition, electron beam vapor deposition, ion beam vapor deposition, and plasma-assisted vapor deposition), thermal CVD, catalytic chemical vapor deposition (Cat-CVD), capacitively coupled plasma CVD (CCP-CVD), photo-assisted CVD, plasma-enhanced CVD (PECVD), epitaxial growth, and chemical vapor deposition methods such as atomic layer deposition (ALD). Among these, ALD and CVD are preferred as gas phase methods.

[0142] The first sealing layer contains silicon nitride (SiNx), silicon oxynitride (SiNOx), or silicon oxide (SiOx). In a specific example of forming the first sealing layer, the pressure inside the chamber is reduced, and silane (SiH ４ ), ammonia (NH ３ ), hydrogen (H ２ The thickness of the first sealing layer is preferably in the range of 10 to 1000 nm, and more preferably in the range of 100 to 500 nm, for example.

[0143] <Second sealing layer forming step> The second sealing layer forming step forms a second sealing layer by applying the sealing composition of the present invention onto the first sealing layer. Specifically, the second sealing layer forming step includes a step of applying the sealing composition onto the first sealing layer (application step) and curing the resulting coating film by ultraviolet irradiation under a nitrogen atmosphere. The second sealing layer forming step may also include a step of modifying the coating film by irradiating it with vacuum ultraviolet light.

[0144] (Coating step) Any appropriate method can be adopted as a method for coating the sealing composition. Examples of the coating method include spin coating, roll coating, flow coating, inkjet coating, spray coating, printing, dip coating, casting, bar coating, and gravure printing. Among these, the inkjet method is preferred because it allows fine patterning, which is required for sealing electronic devices such as organic EL elements, to be performed on demand.

[0145] Known inkjet methods can be used. Inkjet methods are broadly divided into drop-on-demand methods and continuous methods, and either can be used. Drop-on-demand methods include electro-mechanical conversion methods (e.g., single-cavity type, double-cavity type, bender type, piston type, shear-mode type, shared-wall type, etc.), electro-thermal conversion methods (e.g., thermal inkjet type, bubble jet (registered trademark) type, etc.), electrostatic suction methods (e.g., electric field control type, slit jet type, etc.), and discharge methods (e.g., spark jet type, etc.). From the standpoint of inkjet head cost and productivity, it is preferable to use an electro-mechanical conversion type or electro-thermal conversion type head. Note that a method of dropping droplets (e.g., coating liquid) using an inkjet method is sometimes called an "inkjet method."

[0146] The sealing composition is preferably applied in a nitrogen atmosphere.

[0147] (Curing Treatment Step) In the curing treatment step, after the coating step, the obtained coating film is irradiated with ultraviolet light in a nitrogen gas atmosphere. The illuminance of the ultraviolet light on the coating film surface is 10 to 500 mW / cm. ２ It is preferable to cure the composition by irradiating the composition for 1 to 100 seconds within the range of 1 to 100 seconds, but this is not a limitation. As the ultraviolet light, it is preferable to use an LED with a wavelength of 395 nm in order to prevent deterioration of the electronic device.

[0148] (Modification Treatment Step) The modification treatment step may include a step of irradiating the resulting coating film with vacuum ultraviolet light in a nitrogen atmosphere after the coating step to perform a modification treatment. The modification treatment refers to a conversion reaction of polysilazane to silicon oxide or silicon oxynitride. The modification treatment is similarly performed in a nitrogen atmosphere or under reduced pressure, such as in a glove box. The modification treatment in the present invention can be performed using a known method based on the conversion reaction of polysilazane. In the present invention, a conversion reaction using plasma, ozone, or ultraviolet light, which can perform a conversion reaction at low temperature, is preferred. Conventionally known methods for plasma and ozone can be used. In the present invention, the second sealing layer according to the present invention is preferably formed by providing the above-mentioned coating film and modifying it by irradiating it with vacuum ultraviolet light (also referred to as VUV) having a wavelength of 200 nm or less.

[0149] 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. The entire second sealing layer may be modified, 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.

[0150] In the step of modifying the coating film by irradiating it with vacuum ultraviolet rays, the illuminance of the vacuum ultraviolet rays on the surface of the coating film is 30 to 200 mW / cm ２ The illuminance is preferably in the range of 50 to 160 mW / cm. ２ It is more preferable that the irradiance of the vacuum ultraviolet light is within the range of 30 mW / cm. ２ By setting the intensity to 200 mW / cm or more, the modification efficiency can be sufficiently improved. ２The following is preferable because it can significantly reduce the rate of damage to the coating film and also reduce damage to the substrate.

[0151] The irradiation energy of vacuum ultraviolet rays on the coating film surface is 1 to 10 J / cm ２ From the viewpoint of barrier properties and moist heat resistance for maintaining the desiccant function, the amount of irradiation energy is preferably in the range of 3 to 7 J / cm. ２ It is more preferable that the range is within the range of

[0152] A rare gas excimer lamp is preferably used as the light source for the vacuum ultraviolet light. Vacuum ultraviolet light is absorbed by oxygen, which tends to reduce the efficiency of the vacuum ultraviolet light irradiation process. Therefore, it is preferable to perform the vacuum ultraviolet light irradiation in a state where the oxygen concentration is as low as possible. That is, the oxygen concentration during vacuum ultraviolet light irradiation is preferably in the range of 10 to 10,000 ppm. The oxygen concentration is more preferably in the range of 50 to 5,000 ppm, even more preferably in the range of 80 to 4,500 ppm, and most preferably in the range of 100 to 1,000 ppm.

[0153] The modification treatment can also be carried out in combination with a heat treatment. The heating conditions are preferably a temperature in the range of 50 to 300°C, more preferably 60 to 150°C, and a time of preferably 1 second to 60 minutes, more preferably 10 seconds to 10 minutes. By combining the heat treatment, the dehydration condensation reaction during modification is promoted, and the modified product can be formed more efficiently.

[0154] Examples of heat treatment methods include a method in which the substrate is brought into contact with a heating element such as a heat block and the coating film is heated by thermal conduction, a method in which the atmosphere is heated by an external heater such as a resistance wire, and a method using light in the infrared region such as an IR heater. These methods are not particularly limited. In addition, a method that can maintain the smoothness of the coating film containing a silicon compound may be appropriately selected.

[0155] <Third sealing layer forming step> In the third sealing layer forming step, a third sealing layer is formed on the second sealing layer by a vapor phase method. As with the vapor phase method used in the first sealing layer forming step, examples of the vapor phase method include sputtering (e.g., magnetron cathode sputtering, planar magnetron sputtering, bipolar AC planar magnetron sputtering, bipolar AC rotating magnetron sputtering, and other reactive sputtering methods), vapor deposition (e.g., resistance heating vapor deposition, electron beam vapor deposition, ion beam vapor deposition, plasma-assisted vapor deposition, and other methods), thermal CVD, catalytic chemical vapor deposition (Cat-CVD), capacitively coupled plasma CVD (CCP-CVD), photo-assisted CVD, plasma-enhanced CVD (PE-CVD), epitaxial growth, and chemical vapor deposition methods such as atomic layer deposition (ALD). Among these, ALD and CVD are preferred as the vapor phase methods.

[0156] The third sealing layer contains silicon nitride (SiNx), silicon oxynitride (SiNOx), or silicon oxide (SiOx). In a specific example of forming the third sealing layer, the pressure in the chamber is reduced, and silane (SiH ４ ), ammonia (NH ３ ), hydrogen (H ２ 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, for example.

[0157] As described above, a conductive film for a touch sensor may be formed after the sealing film is formed. The conductive film may be formed of a metal compound film such as ITO (indium tin oxide) or IZO (indium zinc oxide). The conductive film may be formed of a highly flexible graphene film, 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). The conductive film may be formed of a multi-metal laminate film such as an Al film / Ti film / Al film.

[0158] [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 includes an inorganic protective layer (first sealing layer) containing silicon nitride, silicon oxide, or silicon oxynitride, and an organic protective layer (second sealing layer) using the electronic device sealing composition described above. Such an electronic device sealing film of the present invention is formed by the electronic device sealing film forming method described above. That is, the organic protective layer (second sealing layer) is formed using the electronic device sealing composition described above. Furthermore, it is preferable that a second inorganic protective layer (third sealing layer) containing silicon nitride, silicon oxide, or silicon oxynitride is formed by a vapor phase method on the organic protective layer (second sealing layer).

[0159] In the electronic device sealing film of the present invention, the density of the organic protective layer (second sealing layer) at 25° C. is 0.85 to 1.08 g / cm ３ The organic protective layer (second sealing layer) preferably contains at least a monomer having an average number of oxygen atoms in one molecule of 2.5 to 3.0 or a monomer having 3 or less double bonds in one molecule.

[0160] <First sealing layer> The first sealing layer is a layer formed on an electronic device by the vapor phase method described above. Specifically, the first sealing layer contains silicon nitride, silicon oxide (silicon monoxide, silicon dioxide, etc.), or silicon oxynitride.

[0161] The second sealing layer is provided adjacent to the first sealing layer and is formed by applying the sealing composition onto the first sealing layer, and therefore contains a polymer made of a specific photopolymerizable monomer contained in the sealing composition.

[0162] As a method for detecting whether the second sealing layer contains the polymer, various conventionally known analytical methods, such as chromatography, infrared spectroscopy, ultraviolet-visible spectroscopy, nuclear magnetic resonance analysis, X-ray diffraction, mass spectroscopy, and X-ray photoelectron spectroscopy, can be used.

[0163] The third sealing layer is a layer formed adjacent to the second sealing layer by the vapor deposition method described above. Specifically, like the first sealing layer, the third sealing layer contains silicon nitride, silicon oxide (silicon monoxide, silicon dioxide, etc.), or silicon oxynitride.

[0164] [Electronic Device] In the method for forming an electronic device sealing film and the electronic device sealing film of the present invention, examples of the electronic device to be sealed include organic EL elements, LED elements, and liquid crystal display elements (LCDs). Examples of the electronic device include thin film transistors, touch panels, electronic paper, and solar cells (PV). From the viewpoint of more efficiently achieving the effects of the present invention, organic EL elements, solar cells, and LED elements are preferred, and organic EL elements are particularly preferred.

[0165] <Organic EL element> The organic EL element employed as the electronic device according to the present invention may be a bottom-emission type, i.e., an element configured to extract light from the transparent substrate side. Specifically, the bottom-emission type is configured by laminating a transparent electrode serving as a cathode, a light-emitting functional layer, and a counter electrode serving as an anode, in this order, on a transparent substrate. Alternatively, the organic EL element according to the present invention may be a top-emission type, i.e., an element configured to extract light from the transparent electrode serving as a cathode side, opposite the substrate. Specifically, the top-emission type is configured by providing a counter electrode serving as an anode on the substrate side, and laminating a light-emitting functional layer and a transparent electrode serving as a cathode, in this order, on the surface of the counter electrode.

[0166] Representative examples of the structure of an organic EL device are shown below: (i) anode / hole injection transport layer / light-emitting layer / electron injection transport layer / cathode (ii) anode / hole injection transport layer / light-emitting layer / hole blocking layer / electron injection transport layer / cathode (iii) anode / hole injection transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron injection transport layer / cathode (iv) anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (v) anode / hole injection layer / hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode (vi) anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode Furthermore, the organic EL device may have a non-light-emitting intermediate layer. The intermediate layer may be a charge generation layer or may have a multi-photon unit structure.

[0167] For an overview of organic EL elements applicable to the present invention, see, for example, JP-A-2013-157634, JP-A-2013-168552, JP-A-2013-177361, JP-A-2013-187211, JP-A-2013-191644, JP-A-2013-191804, JP-A-2013-225678, JP-A-2013-235994, and JP-A-2013-243234. Examples of the configurations described in JP-A-2013-243236, JP-A-2013-242366, JP-A-2013-243371, JP-A-2013-245179, JP-A-2014-003249, JP-A-2014-003299, JP-A-2014-013910, JP-A-2014-017493, JP-A-2014-017494, and the like can be given.

[0168] <Substrate> Specifically, glass or a resin film is preferably used as the substrate for the organic EL element. When flexibility is required, a resin film is preferably used as the substrate. Hereinafter, the substrate may also be referred to as a support substrate, base, substrate, support, etc. The substrate may be transparent or opaque. In the case of a so-called bottom emission type in which light is extracted from the substrate side, the substrate is preferably transparent.

[0169] Preferred resins include substrates containing thermoplastic resins such as polyester resins, methacrylic resins, methacrylic acid-maleic acid copolymers, polystyrene resins, transparent fluororesins, polyimides, fluorinated polyimide resins, polyamide resins, polyamideimide resins, polyetherimide resins, cellulose acylate resins, polyurethane resins, polyether ether ketone resins, polycarbonate resins, alicyclic polyolefin resins, polyarylate resins, polyethersulfone resins, polysulfone resins, cycloolefin copolymers, fluorene ring-modified polycarbonate resins, alicyclic polycarbonate resins, fluorene ring-modified polyester resins, and acryloyl compounds. These resins can be used alone or in combination of two or more.

[0170] The substrate is preferably made of a heat-resistant material. Specifically, a substrate having a linear expansion coefficient of 15 ppm / K to 100 ppm / K and a glass transition temperature (Tg) of 100°C to 300°C is used. This substrate meets the requirements for electronic component applications and laminate films for displays. That is, when the sealing film of the present invention is used for these applications, the substrate may be exposed to processes at 150°C or higher. In this case, if the linear expansion coefficient of the substrate exceeds 100 ppm / K, the substrate dimensions will not be stable when subjected to processes at such temperatures. Therefore, thermal expansion and contraction can lead to problems such as deterioration of barrier properties or inability to withstand thermal processes. If the linear expansion coefficient is less than 15 ppm / K, the film may crack like glass, resulting in poor flexibility.

[0171] The Tg and linear expansion coefficient of the substrate can be adjusted by additives, etc. More preferred specific examples of thermoplastic resins that can be used as the substrate include polyethylene terephthalate (PET: 70°C), polyethylene naphthalate (PEN: 120°C), polycarbonate (PC: 140°C), alicyclic polyolefins (e.g., Zeonor (registered trademark) 1600 manufactured by Zeon Corporation: 160°C), polyarylate (PAr: 210°C), polyethersulfone (PES: 220°C), polysulfone (PSF: 190°C), cycloolefin copolymers (CO C: compound described in JP 2001-150584 A: 162°C), polyimide (for example, Neoprim (registered trademark) manufactured by Mitsubishi Gas Chemical Company, Inc.: 260°C), fluorene ring-modified polycarbonate (BCF-PC: compound described in JP 2000-227603 A: 225°C), alicyclic modified polycarbonate (IP-PC: compound described in JP 2000-227603 A: 205°C), acryloyl compound (compound described in JP 2002-80616 A: 300°C or higher), etc. The temperature in parentheses indicates Tg.

[0172] Since the electronic device according to the present invention is an electronic device such as an organic EL element, the substrate is preferably transparent. That is, the light transmittance is usually 80% or more, preferably 85% or more, and more preferably 90% or more. The light transmittance can be calculated by measuring the total light transmittance and the amount of scattered light using an integrating sphere light transmittance measuring device according to the method described in JIS K7105:1981, and subtracting the diffuse transmittance from the total light transmittance.

[0173] The substrates described above may be unstretched films or stretched films. The substrates can be produced by conventional methods. The methods for producing these substrates may be appropriately selected from those described in paragraphs "0051" to "0055" of International Publication No. 2013 / 002026.

[0174] The surface of the substrate may be subjected to various known treatments for improving adhesion, such as corona discharge treatment, flame treatment, oxidation treatment, or plasma treatment, or may be subjected to a combination of the above treatments as necessary.The substrate may also be subjected to an easy-adhesion treatment.

[0175] The substrate may be a single layer or a laminated structure of two or more layers. When the substrate has a laminated structure of two or more layers, the substrates may be the same type or different types.

[0176] The thickness of the substrate according to the present invention (total thickness when it has a laminated structure of two or more layers) is preferably 10 to 200 μm, more preferably 20 to 150 μm.

[0177] In the case of a film substrate, it is preferable that the film substrate has a gas barrier layer.

[0178] The gas barrier layer for the film substrate may have a water vapor permeability of 0.01 g / m or less, measured according to JIS K 7129-1992, and may have a water vapor permeability of 0.01 g / m or less, or a water vapor permeability of 0.01 g / m or less, measured according to JIS K 7129-1992. ２ The barrier film is preferably a film having a life of 24 hours or less. The measurement conditions are 25±0.5°C and a relative humidity of (90±2)% RH. Furthermore, the oxygen permeability measured by a method in accordance with JIS K 7126-1987 is 1×10 －３ mL / m ２ ・24h・atm or less, water vapor permeability is 1 x 10 －３ g / m ２ It is preferable that the film has high gas barrier properties of 24 hours or less.

[0179] The material for forming the gas barrier layer may be any material that has the function of preventing the penetration of substances that cause deterioration of the element, such as moisture and oxygen, etc. Examples of such materials that can be used include silicon monoxide, silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, and silicon oxycarbide.

[0180] 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, or silicon oxycarbide, the layer is preferably formed from an inorganic material by a sputtering method (e.g., magnetron cathode sputtering, planar magnetron sputtering, bipolar AC planar magnetron sputtering, bipolar AC rotary magnetron sputtering, etc.), a vapor deposition method (e.g., resistance heating vapor deposition, electron beam vapor deposition, ion beam vapor deposition, plasma-assisted vapor deposition, etc.), a thermal CVD method, catalytic chemical vapor deposition (Cat-CVD), capacitively coupled plasma CVD (CCP-CVD), photo-CVD, plasma CVD (PE-CVD), epitaxial growth, atomic layer deposition (ALD), reactive sputtering, or other chemical vapor deposition method.

[0181] The inorganic gas barrier layer can be formed by applying a coating liquid containing an inorganic precursor such as polysilazane or tetraethyl orthosilicate (TEOS) onto a support, and then modifying the coating by irradiating with vacuum ultraviolet light, etc. Alternatively, the inorganic gas barrier layer can be formed by film metallization techniques such as metal plating on a resin substrate or bonding a metal foil to a resin substrate.

[0182] The inorganic gas barrier layer may also include an organic layer containing an organic polymer, i.e., the inorganic gas barrier layer may be a laminate of an inorganic layer containing an inorganic material and an organic layer.

[0183] The organic layer can be formed, for example, by applying an organic monomer or organic oligomer to a resin substrate to form a layer, followed by polymerization and, if necessary, crosslinking using, for example, an electron beam device, a UV light source, a discharge device, or other suitable device. The organic layer can also be formed, for example, by flash evaporation and vapor deposition of a radiation-crosslinkable organic monomer or organic oligomer, followed by forming a polymer from the organic monomer or organic oligomer. Coating efficiency can be improved by cooling the resin substrate.

[0184] Examples of the method for applying the organic monomer or organic oligomer include roll coating (e.g., gravure roll coating), spray coating (e.g., electrostatic spray coating), etc. Examples of the laminate of an inorganic layer and an organic layer include the laminates described in WO 2012 / 003198 and WO 2011 / 013341.

[0185] In the case of a laminate of an inorganic layer and an organic layer, the thicknesses of the layers may be the same or different. The thickness of the inorganic layer is preferably in the range of 3 to 1,000 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.

[0186] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In the following examples, unless otherwise specified, operations were carried out at room temperature (25°C). Furthermore, unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively.

[0187] [Monomer] The photopolymerizable monomers used to prepare the encapsulating composition are as shown in the table below. The number of oxygen atoms (number of O atoms) per molecule and the number of double bonds per molecule for each monomer are also shown in the table below.

[0188]

[0189] [Additives such as photopolymerization initiators] Additives such as photopolymerization initiators used in preparing the sealing composition are as shown in the table below.

[0190]

[0191] [Preparation of Sealing Compositions 1 to 27] Sealing compositions 1 to 27 were obtained by the following procedure. (1) Preparation of Solution: Each photopolymerizable monomer and additive were mixed to obtain formulations A to K shown in Tables III and IV below, and the mixture was placed in a brown bottle. This was then stirred on a hot plate at 60°C for 3 hours to dissolve the additives.

[0192]

[0193]

[0194] (2) Dehydration The prepared compositions were dehydrated under the conditions shown in Tables V to VIII below. (2a) Distillation Vacuum distillation was performed at a pressure of 20 kPa or less at the distillation temperature (dehydration temperature) and time shown in Tables V to VIII below. Distillation was performed while bubbling with nitrogen. (2b) Molecular sieve 10% by mass of molecular sieve 3A (manufactured by Shinwa Chemical Industry Co., Ltd.) was added to the prepared compositions, and the mixture was allowed to stand at room temperature (25°C) for 36 hours while stirring every 12 hours. The supernatant was then collected as the dehydrated composition. Note that distillation using molecular sieves is abbreviated as "MS" in the tables below.

[0195] (3) Degassing The dehydrated composition was degassed under reduced pressure using a hollow fiber degassing module "SEPAREL PF-001D (manufactured by DIC Corporation)."

[0196] (4) Filtration with a Metal Removal Filter The degassed composition was filtered with a metal removal filter "IR-DA47-SCPD (manufactured by 3M)" (for removing Na), and then further filtered with a metal removal filter "MIR-DA47-APP (manufactured by 3M)" (for removing Al and Fe). In this manner, sealing compositions 1 to 27 were obtained.

[0197] The resulting sealing composition was subjected to the following measurements and evaluations. <Measurement of density of uncured sealing composition> The sealing composition was placed in a 10 ml volumetric flask. The mass of the sealing composition was measured using a precision electronic balance with a minimum display of 0.001 g (1 mg), and the density at 25°C was calculated.

[0198] <Measurement of Density of Cured Film> The sealing composition was applied to a PET film to a thickness of about 50 to 100 μm. ２ The cumulative light intensity under these conditions is 1.5 J / cm ２ The coating was cured by irradiating it with ultraviolet light having a wavelength of 395 nm (MZ 240 mm 395 nm UVLED manufactured by IST Corporation) so that the density of the cured film at 25°C was measured by the underwater displacement method described in JIS-K-7112 after peeling it from the PET film.

[0199] <Moisture Content> To measure the moisture content of the sealing composition, Aquamicron AX and Aquamicron CXU (manufactured by Mitsubishi Chemical Corporation) were used as Karl Fischer solutions. Furthermore, a Karl Fischer trace moisture analyzer CA-200 (manufactured by Mitsubishi Chemical Analytech Co., Ltd.) was used as the measuring device. The measurement environment was a dry room at 20°C with a dew point of -50°C.

[0200] <Latency> The sealing composition was placed in an inkjet printer cartridge and maintained at 25°C. Droplets of the sealing composition were ejected from the nozzle of the inkjet printer. After that, the ejection was interrupted for a certain period of time without capping, and then droplets of the sealing composition were ejected again. The ejection state was photographed with a high-speed camera, and the time from when the droplets were ejected from the nozzle to when they landed on the substrate was measured. The distance from the nozzle to the substrate was also measured. The change in ejection velocity before and after the interruption was calculated from the time to when the droplets landed and the distance. The interruption time was varied as follows: 5 seconds, 10 seconds, 15 seconds, 30 seconds, 50 seconds, 75 seconds, 100 seconds, 300 seconds, 500 seconds, 750 seconds, and 1000 seconds. The change in the time from when the droplets were ejected to when they landed before and after the interruption, i.e., the maximum interruption time at which the droplet velocity changed by 3% or less, was defined as the latency.

[0201] <Contents of Al, Fe, and Na> The contents of Al, Fe, and Na in the sealing composition were measured using a CP optical emission spectrometer SPS3520UV (Hitachi). The total contents of each element are shown in the table below.

[0202] <Slope of Spectral Transmission Spectrum> The spectral transmission spectra of sealing compositions 5 and 23 to 27 were measured using a spectrophotometer V650 (manufactured by JASCO Corporation). The transmittance at 650 nm was normalized to 100%. A tangent line was drawn at 450 nm to the normalized spectral curve, and the slope of the tangent line was determined (see FIGS. 1 and 2).

[0203] [Evaluation] <Wrinkle-like defects> Silicon nitride (SiNx) was formed to a thickness of 500 nm on a 50 mm x 50 mm glass substrate by a plasma CVD method. Then, a coating film of a sealing composition was formed to a thickness of 10 μm by an inkjet method in a nitrogen environment. This coating film was then irradiated with 300 mW / cm under a nitrogen environment. ２ The cumulative light intensity under these conditions is 1.5 J / cm ２ The coating was cured by UV irradiation to obtain a measurement sample. The glass substrate was placed face down under an optical microscope, and wrinkle defects were observed and evaluated in the entire 50 mm x 50 mm area using transmission mode at 1000x magnification according to the following criteria: (Criteria) S: No wrinkle defects were observed. A: 1 to 5 wrinkle defects were observed, but it was determined that this did not affect visibility. B: 6 to 10 wrinkle defects were observed, but it was determined that the coating was usable. C: 11 to 14 wrinkle defects were observed, but it was determined that the coating was usable for low-cost products. D: 15 or more wrinkle defects were observed, and it was determined that the coating was not usable.

[0204] <Scratches> The measurement sample observed for wrinkle defects was placed on a large glass plate with the cured film side facing down, and slowly pushed from the side of the sample at a speed of about 2 cm / sec, sliding it 10 cm. After sliding, the sample was placed under an optical microscope with the glass substrate facing down, and scratches (abrasions) over the entire 50 mm x 50 mm area were observed and evaluated in reflection mode at 500x magnification according to the following criteria. (Criteria) S: No scratches were observed. A: 1 to 3 scratches were observed, but it was determined that there was no impact on visibility. B: 4 to 7 scratches were observed, but it was determined that the sample was usable. C: 8 to 10 scratches were observed, but it was determined that the sample was usable for low-cost products. D: 11 or more scratches were observed, and it was determined that the sample was not usable for practical use.

[0205]

[0206]

[0207]

[0208]

[0209] As shown by the above results, it was found that the sealing composition of the present invention can prevent the occurrence of scratches and wrinkle-like defects in the sealing film, compared to the sealing composition of the comparative example.

Claims

1. An electronic device sealing composition for inkjet printing, comprising a photopolymerizable monomer and a photopolymerization initiator, wherein the photopolymerizable monomer is a (meth)acrylate, and the density of the uncured sealing composition at 25°C is 0.85 to 1.08 g / cm ３ and the water content measured by the Karl Fischer method is 100 ppm by mass or less.

2. The composition for electronic device sealing for ink jet printing according to claim 1, wherein the water content is 5 ppm by mass or more.

3. The electronic device sealing composition for inkjet use according to claim 1, wherein when the inkjet ejection of the sealing composition is interrupted and then ejected again, the latency at which the change in droplet speed before and after the ejection is interrupted is ±3% or less is 20 seconds or more.

4. The density of the uncured sealing composition at 25°C is 0.94 to 1.05 g / cm ３ The composition for electronic device encapsulation for ink jet application according to claim 1 , wherein the range is 5. The electronic device sealing composition for inkjet use according to claim 1, wherein the total content of each of the elements aluminum (Al), iron (Fe), and sodium (Na) contained in the sealing composition is 1 mass ppm or less with respect to the total amount of the sealing composition.

6. The composition for sealing electronic devices for ink jet printing according to claim 1, wherein the average number of oxygen atoms contained in one molecule of all of said photopolymerizable monomers is 2.5 or more and 3.0 or less.

7. The electronic device sealing composition for inkjet use according to claim 1, wherein, when the spectral transmission spectrum of the sealing composition is measured, a light transmittance vs. light wavelength peak curve is obtained by normalizing the transmittance at a transmitted light wavelength of 650 nm to 100%, and the slope of the tangent at a wavelength of 450 nm is within the range of 2.5 to 5.0% / nm.

8. The composition for sealing electronic devices for inkjet printing according to claim 1, wherein all of the photopolymerizable monomers contain 30% by mass or more of monomers having 3 or less double bonds in one molecule.

9. A method for producing a composition for sealing electronic devices according to any one of claims 1 to 8, comprising the steps of preparing a solution of the photopolymerizable monomer and the photopolymerization initiator, and then dehydrating the solution.

10. The method for producing a composition for sealing electronic devices according to claim 9, further comprising a degassing step after the step of preparing the composition.

11. The method for producing a composition for sealing electronic devices according to claim 9, further comprising a step of filtering the composition through a metal removal filter after the step of preparing the composition.

12. An electronic device sealing film for sealing an electronic device, comprising: an inorganic protective layer containing silicon nitride, silicon oxide or silicon oxynitride; and an organic protective layer formed using the electronic device sealing composition according to any one of claims 1 to 8.

13. The density of the organic protective layer at 25° C. is 0.85 to 1.08 g / cm ３ The electronic device sealing film according to claim 12 .

14. The electronic device sealing film according to claim 12, wherein the organic protective layer contains at least a monomer having an average number of oxygen atoms in one molecule of 2.5 to 3.0, or a monomer having 3 or less double bonds in one molecule.

15. A method for forming a sealing film using the composition for electronic device sealing according to any one of claims 1 to 8, comprising the steps of: forming an inorganic protective layer on an electronic device by a vapor phase method; and forming an organic protective layer by applying the composition for electronic device sealing on the inorganic protective layer.

16. The method for forming an electronic device sealing film according to claim 15, further comprising a step of forming a second inorganic protective layer containing silicon nitride, silicon oxide or silicon oxynitride by a vapor phase method on the organic protective layer.

17. The method for forming an electronic device sealing film according to claim 15, wherein an ink-jet method is used in the step of forming the organic protective layer.

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