JP2008010299A - Sealing film of inorganic el element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing film of an inorganic electroluminescence (EL) element which is a film for sealing the inorganic EL element, and has excellent moisture-proof and antifouling properties where air or the like does not remain especially in an inside with the inorganic EL element sealed. <P>SOLUTION: The sealing film of the inorganic EL element is characterized by that a ventilating passage formed by a plurality of recessed parts, which connect an end edge and other end edge, is formed on a surface of a thermal adhesive resin layer on an inorganic EL element side in the inside of the sealing film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a film for sealing an inorganic electroluminescence (EL) element. In particular, the present invention relates to a sealing film for an inorganic EL element that is excellent in moisture resistance and antifouling property, in which air or the like does not remain inside the sealed inorganic EL element.

As shown in FIG. 11, an electroluminescence (EL) element is usually a polymer EL substrate in which a transparent or semitransparent conductive layer 102, a polymer light emitting layer 103, and a cathode layer 1044 are sequentially laminated on a transparent substrate 101. 105 and two or more terminal electrodes 113 include a first multilayer sealing film 108 made of at least a transparent gas barrier film and a sealant, and a second multilayer sealing film 112 made of at least a metal foil and a sealant. It is vacuum-sealed in the sealing package.

  One end of the terminal electrode is in contact with either the conductive layer or the cathode layer of the polymer EL substrate, and the other end is exposed to the outside from the vacuum-sealed seal portion.

  Further, the electroluminescence (EL) element is an all-solid display unlike a liquid crystal display having high visibility due to self-coloring. And, it has advantages such as being hardly affected by temperature change and having a large viewing angle.

  For this reason, in recent years, it has been put to practical use as a pixel of a display device and a back light source of a liquid crystal display.

  The EL element includes an inorganic EL element and an organic EL element. As an inorganic EL element, for example, an EL layer is formed by sandwiching both surfaces of a light emitting layer in which manganese is added to zinc sulfide with a ferroelectric layer.

  As described above, this EL layer has a structure in which a strip-shaped transparent electrode is provided on one surface, a strip-shaped electrode is provided on the other surface, and a glass substrate is disposed on the strip-shaped transparent electrode side.

  In addition, the organic EL element is configured by laminating a hole injection layer made of diamine or the like on a light emitting layer made of an aluminum quinoline complex or the like to form an EL layer, and a strip-shaped transparent electrode on one surface of the EL layer It has a structure in which a booklet electrode is provided on the other surface and a glass substrate is arranged on the strip-like transparent electrode side.

  In addition, a light emitting layer in which an inorganic fluorescent material in which an activator such as manganese is added to zinc sulfide is dispersed in a transparent dielectric is interposed between two electrodes facing each other (the electrode on the light emitting surface side is a transparent electrode). Dispersion type formed by forming a laminated structure on a transparent substrate.

Alternatively, the light emitting layer made of an inorganic fluorescent material is sealed with two transparent inorganic insulators (dielectric layers) made of Si ₃ N ₄ , Al ₂ O _3, etc., and two electrodes (the light emitting surface side electrode is a transparent electrode) And a three-layer thin film type formed by forming a laminated structure interposed between them on a transparent substrate.

  And what the outer surface of these laminated structures is coat | covered with the fluorine-type polymer thin film which consists of a fluorine-containing copolymer which has a cyclic structure is known (for example, refer patent document 1).

  Furthermore, a weather-proof moisture-proof film (for example, see Patent Document 2) using a fluorine-based resin as a moisture-proof film base material for EL element coating and sealing excellent in moisture resistance, light resistance, and weather resistance is known.

  The weatherproof moisture-proof film 100 is formed of a laminated film in which a moisture-proof layer 133 is formed on at least one surface of a plastic film 131 as shown in FIG. The moisture-proof layer 133 is a layer having stretched polypropylene as a base material.

  The outermost layer 2 of the laminated film is formed of a fluorine resin coating film (A) or a coating film (B) containing a hydrolyzed partial condensate of organoalkoxysilane and a silyl group-containing vinyl resin. A sealant layer 4 for imparting adhesiveness is formed on the side of the plastic film 1 opposite to the outermost layer 2.

  However, the inorganic EL element as described above has a problem of deterioration of the characteristics of the light emitting layer due to the intrusion of moisture and a decrease in durability. For example, when moisture enters the EL element from the outside, the humidity is increased as the temperature increases due to operation energization. It vaporizes and expands, and peeling between the EL layer and the electrode occurs.

  When such peeling occurs, a voltage is not applied to the EL layer, and there is a concern that there will be a black spot defect without emitting light, and the environmental compatibility of fluororesins (such as environmental hormones).

  An inorganic EL element sealing film (for example, for obtaining an inorganic electroluminescence (EL) element that is highly reliable and moisture-proof and antifouling without using a fluorine-based resin having a concern for environmental compatibility) (See Patent Document 3).

  As shown in FIG. 13, the inorganic EL element sealing film 200 includes a photocatalytic film 300 in which a titanium oxide coat layer 122 is formed on one side of a polyester film base 121, and an inorganic oxide on one side of the polyester film base 123. The deposited thin film layer 124 and the gas barrier coating layer 125 are alternately and repeatedly laminated several times, and the sealant layer 126 is formed on the gas barrier coating layer 125 of the vapor deposition film formed so that the gas barrier coating layer 125 becomes the outermost layer. Is formed.

Prior art documents are shown below.
JP-A-4-355096 JP-A-8-187825 JP 2004-338201 A

  However, when the inorganic EL element sealing film of Patent Document 3 is sealed, there is a problem that air or the like remains in the sealed interior as in the conventional laminated sealing film such as Patent Document 1 or Patent Document 2. is there. The remaining air becomes air bubbles, causing unevenness in light emission, which hinders uniform display.

The present invention has been made in view of the above-described conventional problems, and the problem is that when sealing, no air or the like remains in the sealed interior, and the moisture-proof, An object of the present invention is to provide an inorganic EL element sealing film for obtaining a highly reliable inorganic electroluminescence (EL) element that is excellent in soiling and does not use a fluorine-based resin having a concern for environmental compatibility. To do.

In order to solve the above problems, the invention according to claim 1 of the present invention provides:
An inorganic EL element sealing film,
An inorganic EL element characterized in that an air passage by a plurality of concave portions is formed on the surface of the thermal adhesive resin layer on the inorganic EL element side inside the sealing film, and the edge is connected to another edge. It is a sealing film.

Next, the invention according to claim 2 of the present invention is as follows:
The inorganic EL element sealing film according to claim 1, wherein the air passages formed by the plurality of recesses are formed by an extruder.

  Since the sealing film of the inorganic EL element of this invention consists of the above structures, when vacuum-sealing, the air etc. in an inorganic EL element can be removed completely. In addition, it is possible to provide a sealing film for an inorganic electroluminescence (EL) element which can form a uniform indoor or outdoor display body such as a signboard or a sign without unevenness in light emission.

  In addition, it has excellent moisture resistance and antifouling properties, and also has excellent water vapor barrier properties, preventing moisture from entering the device from the outside, thereby preventing defects caused by vaporization and expansion of moisture inside the device. Generation can be prevented.

  The materials constituting the sealing film of the inorganic EL element of the present invention are excellent in environmental adaptability because they do not use a conventionally used fluorine resin or the like.

  When vacuum-sealing, it is easy to remove the vacuum. In addition, a highly reliable inorganic EL element can be obtained in which the vacuum sealing operation is efficiently, stably performed in a short time.

  The sealing film of the inorganic EL element of this invention is demonstrated in detail, referring drawings below along embodiment.

  FIG. 1 is a cross-sectional view showing a cross section of one embodiment of the structure of the sealing film of the inorganic EL element of the present invention. Moreover, FIG. 2 is sectional drawing which shows the cross section of another Example of a structure of the sealing film of the inorganic EL element of this invention.

  As shown in FIG. 1, the sealing film 1 of the inorganic EL element of this invention has the vapor deposition thin film layer 12 which consists of an inorganic oxide on the single side | surface of the plastic film base material 11. As shown in FIG.

  Further, a water-soluble polymer provided on the vapor-deposited thin film layer 12, (a) one or more metal alkoxides and / or hydrolysates thereof, or (b) an aqueous solution containing at least one of tin chloride or water / A sealant layer 14 is laminated on the outermost gas barrier coating layer 13 of the vapor deposition film 20 in which a gas barrier coating layer 33 formed by applying a coating agent mainly composed of an alcohol mixed solution and drying by heating is alternately and repeatedly laminated twice. Laminated material.

  On the surface of the sealant layer 14, air passages 15 are formed by a plurality of recesses that connect the end edge to the other end edge.

Moreover, although the example which laminated | stacked the said vapor deposition thin film layer and gas barrier film layer which consist of the said inorganic oxide twice alternately was shown, it is not limited to this Example, The vapor deposition thin film layer which consists of inorganic oxides And the gas barrier coating layer may be alternately and repeatedly laminated a plurality of times.

  And as shown in FIG. 2, the inorganic EL element sealing film 2 as another Example of this invention is the vapor deposition thin film which consists of inorganic oxides in the sealing film 1 of the inorganic EL element shown in FIG. The layer 12 and the gas barrier coating layer 13 are alternately and repeatedly laminated four times.

  Examples of the plastic film substrate 11 include those having transparency and sufficient dimensional stability, such as polyester film or nylon film, and polybutylene terephthalate. And what was arbitrarily extended | stretched to biaxial direction from viewpoints, such as heat resistance, is used. Of these, a polyester film is preferably used.

  Specific examples of the resin material for the nylon resin film of the stretched nylon film include polycaproamide (nylon 6), poly-ω-aminoheptanoic acid (nylon 7), poly-9-aminononanoic acid (nylon 9). ), Polyundecanamide (nylon 11), polylaurin lactam (nylon 12), polyethylenediamine adipamide (nylon 2,6), polytetramethylene adipamide (nylon 4,6), polyhexamethylenediadipamide ( Nylon 6,6), polyhexamethylene sebamide (nylon 6,10), polyhexamethylene dodecamide (nylon 6,12), polyoctamethylene adipamide (nylon 8,6), polydecamethylene adipamide (Nylon 10,6), polydecamethylene sebacamide (nylon 10,1 ), Polydodecamethylene dodecamide (nylon 12,12), meta-xylene diamine -6 nylon (MXD6) and the like.

  Examples of nylon copolymer resins include caprolactam / laurin lactam copolymer, caprolactam / hexamethylene diammonium adipate copolymer, laurin lactam / hexamethylene diammonium adipate copolymer, hexamethylene diammonium adipate / hexa. Examples include methylene diammonium sebacate copolymer, ethylene diammonium adipate / hexamethylene diammonium adipate copolymer, caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer, and the like.

  The resin material for the polyester resin film of the stretched polyester film includes polyethylene terephthalate (PET) resin as a homopolyester resin, polyethylene terephthalate structure based on the following copolymerized polyester resins such as terephthalic acid and ethylene glycol. Diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, diglycol as isophthalic acid, phthalic acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, etc. as dibasic acids Copolymers of polybutylene glycol and ethylene oxide adducts of bisphenol derivatives, such as polyethylene naphthalate (PEN) resin and polybutylene Such as terephthalate (PBT) resin can be mentioned.

  As the plastic film substrate 11 used for the sealing films 1 and 2 of the inorganic EL element of the present invention shown in FIG. 1 or 2, the stretched polyester or stretched nylon alone, or the stretched nylon based film alone A plastic film substrate 11 which is either a laminated film formed by laminating a laminated film or a laminated film of stretched nylon films is used.

In addition, the plastic film substrate 11 includes, as general additives, for example, ultraviolet absorbers, antistatic agents, plasticizers, flame retardants, lubricants, fireproofing agents, fungicides, pigments, fillers, and the like. Can be used. The addition amount can be arbitrarily added from a very small amount to several tens of percent depending on the purpose.

  In addition, plastic films are generally deteriorated or yellowed by ultraviolet rays having a wavelength of 400 nm or less. For this reason, an ultraviolet absorber can be kneaded and mixed with the plastic film substrate 11 to block ultraviolet rays, or an ultraviolet absorbing coating layer or the like can be provided within a range that does not impair the transparency of the film.

  Examples of the ultraviolet absorber include metal oxides such as titanium oxide, zinc oxide, cerium oxide, and zirconium oxide, organic substances such as salicylic acid derivatives, benzophenones, benzotriazoles, and substituted acrylonitriles, and nickel complexes. In the system, specifically, 2-methoxyhexyl paramethoxycinnamate, 2-ethylhexyl paradimethylaminobenzoate, oxybenzone, 2-ethylhexyl salicylate, cyanoacrylate, salicylate, and the like are preferably used.

  In the inorganic system, titanium oxide and cerium oxide are preferably used, and zinc oxide is particularly preferable. These metal oxides have a particle size of 5 to 100 nm, preferably 10 to 50 nm.

  Also, in order to improve the adhesion when laminating other layers on this substrate, plasma utilizing corona treatment, low temperature plasma treatment, reactive ion etching (RIE) as a pretreatment on the laminated surface side of the substrate. Any treatment such as treatment, ion bombardment treatment, chemical treatment, and solvent treatment may be performed.

  The thickness of the plastic film substrate 11 is not particularly limited, but is preferably in the range of 12 to 50 μm.

  Next, the vapor-deposited thin film layer 12 made of an inorganic oxide in the sealing films 1 and 2 of the inorganic EL element of the present invention and the gas barrier coating layer 13 provided on the vapor-deposited thin film layer both function as gas barrier layers. It is. Hereinafter, each layer which forms the gas barrier layer in the sealing films 1 and 2 of the inorganic EL element of the present invention will be described in more detail.

  First, the vapor-deposited thin film layer 12 made of an inorganic oxide is made of a vapor-deposited film of an inorganic oxide such as aluminum oxide, silicon oxide, tin oxide, magnesium oxide, or a mixture thereof. And what is necessary is just the layer which has transparency and gas barrier properties, such as oxygen and water vapor | steam.

  Among the above, aluminum oxide, silicon oxide, magnesium oxide or a mixture thereof is particularly preferable. However, the vapor-deposited thin film layer 12 in the sealing films 1 and 2 of the inorganic EL element of the present invention is not limited to the inorganic oxide described above, and any material that meets the above conditions can be used.

  The optimum thickness of the vapor-deposited thin film layer 12 made of an inorganic oxide varies depending on the type and configuration of the inorganic compound used, but is generally in the range of 5 to 300 nm, and the value is appropriately selected. However, if the film thickness is less than 5 nm, a uniform film may not be obtained or the film thickness may not be sufficient, and the function as a gas barrier material may not be sufficiently achieved.

  On the other hand, when the film thickness exceeds 300 nm, flexibility cannot be maintained in the thin film, and the thin film may be cracked due to external factors such as bending and pulling after the film formation. Preferably, it exists in the range of 10-150 micrometers.

  As a method of forming the vapor-deposited thin film layer 12 made of an inorganic oxide on a polyester film substrate, it can be formed by a normal vacuum vapor deposition method. In addition, other thin film forming methods such as sputtering, ion plating, and plasma vapor deposition (CVD) can be used. However, considering productivity, the vacuum deposition method is the best at present.

  It is preferable to use an electron beam heating method, a resistance heating method, or an induction heating method as a heating means of the vacuum vapor deposition method, but an electron beam heating method is used in consideration of the wide selection of evaporation materials. It is preferable.

  Moreover, in order to improve the adhesiveness of the vapor deposition thin film layer 12 and the base material 11, and the denseness of the vapor deposition thin film layer, it is also possible to vapor-deposit using a plasma assist method or an ion beam assist method. In order to increase the transparency of the deposited film, reactive deposition in which various gases such as oxygen gas are blown may be used during the deposition.

  Next, the gas barrier coating layer 13 of the sealing films 1 and 2 of the inorganic EL element of the present invention will be described. The gas barrier coating layer 13 in the present invention is an aqueous solution or water / alcohol mixture containing at least one of a water-soluble polymer and (a) one or more metal alkoxides and / or hydrolysates or (b) tin chloride. It is formed using a coating agent mainly composed of a solution.

  For example, a solution in which a water-soluble polymer and tin chloride are dissolved in an aqueous (water or water / alcohol mixed) solvent, or a solution in which a metal alkoxide is directly or previously hydrolyzed is mixed. Adjust to make a solution. After coating this solution on the vapor deposition thin film layer 22 which consists of inorganic oxides, it heat-drys and forms.

  Each component contained in this coating agent will be described in more detail.

  Examples of the water-soluble polymer used in the coating agent in the present invention include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate and the like.

  In particular, gas barrier properties are most excellent when polyvinyl alcohol (hereinafter abbreviated as PVA) is used in the coating agent of the present invention. PVA here is generally obtained by saponifying polyvinyl acetate. Examples of the PVA include, but are not limited to, complete PVA in which only a few percent of acetic acid groups remain from a so-called partially saponified PVA in which several tens of percent of acetate groups remain.

The tin chloride used for the coating agent may be stannous chloride (SnCl ₂ ), stannic chloride (SnCl ₄ ), or a mixture thereof. These tin chlorides may be anhydrous or hydrated.

Further, the metal alkoxide is a compound represented by a general formula, M (OR) n (M: metal such as Si, Ti, Al, Zr, or alkyl group such as R: CH ₃ or C ₂ H ₅ ). Specific examples include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ], triisopropoxyaluminum [Al (O-2′-C ₃ H ₇ ) ₃ ], and among others, tetraethoxysilane and triisosilane. Propoxyaluminum is preferable because it is relatively stable in an aqueous solvent after hydrolysis.

  As long as the gas barrier property of the coating agent is not impaired, known additives such as isocyanate compounds, silane coupling agents, dispersants, stabilizers, viscosity modifiers, and colorants can be added as necessary.

  For example, the isocyanate compound added to the coating agent is preferably one having two or more isocyanate groups in the molecule. For example, monomers such as tolylene diisocyanate, triphenylmethane triisocyanate, tetramethylxylene diisocyanate, and polymers and derivatives thereof can be mentioned.

  For the coating method of the coating agent, conventionally known means such as a dipping method, a roll coating method, a screen printing method, a spray method, a gravure printing method and the like that are usually used can be used.

  In addition, the thickness of the coating varies depending on the type of coating agent, the processing machine, and the processing conditions. When the thickness after drying is 0.01 μm or less, a uniform coating film may not be obtained and sufficient gas barrier properties may not be obtained.

  Further, when the thickness exceeds 50 μm, there is a problem because cracks are likely to occur in the film. It is preferably in the range of 0.01 to 50 μm, more preferably in the range of 0.1 to 10 μm.

  Next, the sealant layer 14 in the sealing films 1 and 2 of the inorganic EL element of the present invention is made of a resin that can be sealed by heat sealing when sealing the inorganic EL element, and is provided as an adhesive layer.

  The sealant layer 14 is an adhesive thermoplastic resin that can be heat-sealed, and may be any material that can be melted by heat and fused to each other, such as low-density polyethylene, medium-density polyethylene, and high-density polyethylene. , Linear (linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer Polyolefin resins such as ethylene-propylene copolymer, methylpentene polymer, polyethylene or polypropylene, and unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc. It is possible to use acid-modified polyolefin resins modified with Kill.

  Of these, modified polyethylene resins such as ionomers are particularly desirable from the viewpoint of adhesion to the EL extraction electrode. The thickness is determined according to the purpose, but it needs to be at least 1/2 the thickness of the EL extraction electrode, and is generally in the range of 15 to 200 μm.

  The sealant layer 14 can be formed by a dry lamination method in which bonding is performed using an adhesive such as a two-component curable urethane resin, a non-solvent lamination method in which bonding is performed using a solventless adhesive, or a resin is melted by heating. Any known method such as an extrusion lamination method of extruding and pasting in a curtain shape can be used.

  And it can laminate | stack by any well-known method, and the sealing films 1 and 2 of the inorganic EL element of this invention can be obtained, but the film for sealing of the inorganic EL element of this invention can be cheaply and made into the minimum processing process. For production, an extrusion lamination method in which a resin is heated and melted and extruded into a curtain shape is preferable.

A sealant layer 14 is further laminated on the laminated material in which the vapor deposition thin film layer 12 and the gas barrier coating layer 13 are laminated on the plastic substrate 11 by the extrusion lamination method. At the same time, the edge and other edges are formed on the surface of the sealant layer 14. A ventilation path 15 is formed by a plurality of recesses connecting the end edges.

  And the surface shape of the ventilation path 15 by a recessed part may be cross shape, as shown in FIG. Moreover, as shown in FIG. 6, it may be a diagonal line shape and the shape is not specifically limited. The cross section is shown in FIG. 4 (cross section taken along line AA ′ in FIG. 3) or FIG. 5 (cross section taken along line BB ′ in FIG. 3) and FIG. 7 (cross section taken along line CC ′ in FIG. 6). A recess is formed on the surface.

  Further, the air passage 15 formed by a plurality of recesses formed on the surface of the sealant layer 14 connects the edge of the surface of the sealant layer 14 to the other edge as shown in FIGS. A path 15 is formed.

  The interval between the air passages 15 formed by the recesses is preferably 1 to 10 mm or less and about 2 to 6 mm. And the width | variety of the ventilation path 15 is formed in about 0.001 mm-5 mm. Further, the depth of the air passage 15 is about 0.001 to 0.02 mm, preferably about 0.005 to 0.001 mm.

  The air passage 15 formed by a plurality of recesses on the surface of the sealant layer 14 can be formed by a single stamping laminator as shown in FIG.

  As shown in FIG. 8, the single embossing laminator includes a first unwinding portion 21 and a second unwinding portion 22, an anchor coating portion 23 for applying an anchor agent, and drying for drying the applied anchor agent. A section 24, a press roll 25, and a cooling roll 26 are provided.

  And the cooling roll part 27 and the extrusion machine 29 which fuse | melts the thermoplastic resin which laminates and forms the laminated material 28 and the sealant layer 14 which were drawn | fed out from the 1st winding part 21 above the cooling roll part 27, and carries out film-forming fall. The T die 11 connected to the extruder 29 is provided.

  Furthermore, a winding portion 31 is provided on which a winding material 32 that is a sealing film for an inorganic EL element of the present invention, in which the sealant layer 14 is laminated on the laminated material, is wound.

  Further, as shown in FIG. 9, the laminated material 28 fed out from the first unwinding portion 21 is coated with an anchor agent or the like at the anchor coating portion 23 and further dried at the drying portion 24. . Then, the thermoplastic resin melted from the T-die 30 of the extruder 29 provided above the cooling roll unit 27 drops in the direction of the cooling roll unit 27 and is laminated on the laminated material 28.

  At the same time, the surface of the sealant layer 14 is recessed by the cooling roll 12 provided on the outer peripheral surface with the press roll 25 and the plate 33 having a plurality of protrusions formed in the shape as shown in FIG. A ventilation path 15 is formed. Then, it is cooled and taken up by the take-up unit 31.

  The plate on which the plurality of convex portions provided on the outer peripheral surface of the cooling roll 12 is formed is made of copper, a metal such as aluminum or magnesium, an alloy thereof, a nylon resin, a fluororesin, or the like.

A plate using a metal such as copper, aluminum, or magnesium, or an alloy thereof, nylon resin, or fluororesin is formed by applying an uneven portion by mechanical engraving or corrosion processing.

  A pattern such as a pattern is formed by applying uneven portions to the surface of a metal such as copper, aluminum, magnesium, or an alloy thereof by mechanical engraving or corrosion.

  Hereinafter, the sealing film of the inorganic EL element of the present invention will be described in more detail with specific examples, but is not limited thereto.

<Example 1>
As shown in FIG. 10, the laminate material used for the sealing film of the inorganic EL element of the present invention uses a biaxially stretched polyester film (PET) having a thickness of 100 μm for the plastic substrate 11, and one of the laminated materials. On the surface, vapor-deposited thin film layers 12 and gas barrier coating layers 13 made of an inorganic oxide having a thickness of 12 μm were alternately formed twice, and further, an ethylene / vinyl acetate copolymer (EVA) having a thickness of 50 μm was formed on the surface. ) Was used to form the sealant layer 14 to produce the outer film 60.

  The surface shape of the sealant layer 14 was formed with an air passage 15 having a cross-shaped recess as shown in FIG. And the space | interval of the ventilation path 15 by a recessed part was formed in 10 mm, depth 0.001mm, and width 1mm.

  Next, a 75 μm thick biaxially stretched polyester film (PET) is used for the plastic substrate 17, and a 25 μm thick ethylene / vinyl acetate copolymer (EVA) is used on one side thereof, The sealant layer 18 was formed, and the front film 50 was produced.

<Example 2>
In Example 1, the outer side film 60 and the front side film 50 were produced in the same manner as in Example 1 except that the surface shape of the sealant layer 14 was formed with the air passage 15 by the oblique line-shaped recesses as shown in FIG. .

<Example 3>
In Example 1, an outer film 60 and a front film 50 were prepared in the same manner as in Example 1 except that the space between the air passages 15 by the recesses of the sealant layer 14 was 5 mm.

<Example 4>
In Example 2, an outer film 60 and a front film 50 were prepared in the same manner as in Example 2 except that the space between the air passages 15 by the recesses of the sealant layer 14 was 5 mm.

<Comparative Example 1>
In Example 1, an outer film 60 and a front film 50 were prepared in the same manner as in Example 1 except that the distance between the air passages 15 formed by the concave portions of the sealant layer 14 was 20 mm.

<Comparative example 2>
In Example 2, an outer film 60 and a front film 50 were prepared in the same manner as in Example 2 except that the distance between the air passages 15 by the recesses of the sealant layer 14 was 20 mm.

<Comparative Example 3>
In Example 1, an outer film 60 and a front film 50 were prepared in the same manner as in Example 1 except that the air passage 15 formed by the concave portion of the sealant layer 14 was not formed.

<Evaluation>
The outer film 60 and the front film 50 obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were vacuum-sealed with an inorganic EL element at 140 ° C. for 30 seconds using a flat plate press. The occurrence state was visually observed. The results are shown in Table 1.

表１は実施例１〜４および比較例１〜３で得られた外側のフィルム６０と表側のフィルム５０で無機ＥＬ素子を真空封止した際の、気泡の発生状態を目視した結果を記す。

Table 1 shows the result of visual observation of the bubble generation state when the inorganic EL element was vacuum sealed with the outer film 60 and the front film 50 obtained in Examples 1 to 4 and Comparative Examples 1 to 3.

<Evaluation results>
In Examples 1 to 4, when the distance between the air passages 15 by the recesses of the sealant layer 14 is 10 mm or less, the generation state of bubbles when the inorganic EL element is vacuum-sealed is not visually observed, but in Comparative Examples 1 and 2 of 20 mm Bubbles are visually observed. The generation of bubbles is visually observed even in the case where the air passage 15 is not formed by the recess.

  The sealing film for inorganic EL elements of the present invention can be used as a sealing film for inorganic EL elements, as well as other optical barrier materials.

It is sectional drawing which shows the cross section of one Example of the sealing film of the inorganic EL element of this invention. It is sectional drawing which shows the cross section of other Example of the sealing film of the inorganic EL element of this invention. It is a top view which shows the plane of one Example of the shape of the ventilation path 15 by the recessed part formed in the surface of the sealant layer of the sealing film of the inorganic EL element of this invention. FIG. 4 is a schematic cross-sectional view showing a cross section taken along line AA ′ of FIG. 3. It is a cross-sectional schematic diagram which shows the BB 'line cross section of FIG. It is a top view which shows the plane of one Example of the shape of the ventilation path by the recessed part formed in the surface of the sealant layer of the sealing film of the inorganic EL element of this invention. It is a top view which shows the plane of one Example of the shape of the ventilation path by the recessed part formed in the surface of the sealant layer of the sealing film of the inorganic EL element of this invention. It is explanatory drawing for demonstrating one Example which forms the ventilation path 15 by the recessed part formed in the surface of the sealant layer of the sealing film of the inorganic EL element of this invention. It is the schematic explanatory drawing which expanded a part of FIG. It is explanatory drawing for demonstrating the Example of the sealing film of the inorganic EL element of this invention. It is explanatory drawing for demonstrating sealing of an inorganic EL element. It is sectional drawing which shows the cross section of the sealing film of the conventional inorganic EL element. It is sectional drawing which shows the cross section of the sealing film of the conventional inorganic EL element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sealing film of inorganic EL element of this invention 2 ... Sealing film of inorganic EL element of this invention 11 ... Plastic base material layer 12 ... Deposition layer 13 ... Gas barrier coating layer 14 ... Sealant layer 15 ... Air flow path by recessed part 16 ... convex part 17 ... plastic substrate layer 18 ... sealant layer 21 ... first unwinding part 22 ... second unwinding part 23 ... anchor coating part 24 ... drying part 25 ... press roll 26 ... cooling roll 27 ... cooling part 28 ... Laminated material 29 ... Extruder 30 ... T die 31 ... Winding part 32 ... Winding paper of sealing film of inorganic EL element 33 ... Plate 50 ... Front side film 60 ... Outer film

Claims (2)

An inorganic EL element sealing film,
An inorganic EL element characterized in that an air passage by a plurality of concave portions is formed on the surface of the thermal adhesive resin layer on the inorganic EL element side inside the sealing film, and the edge is connected to another edge. Sealing film.   The sealing film for an inorganic EL element according to claim 1, wherein an air passage formed by the plurality of recesses is formed by an extruder.

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