JP2013157228A - Organic el device, and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL device in which warpage is reduced, even if the difference of linear expansion coefficient is large between a circuit substrate and a display substrate.SOLUTION: In the organic EL device including a substrate (H), a surface sealant, a substrate (L), and a shape holding layer in this order, an organic EL element is arranged on the substrate (H) or substrate (L). The substrate (H) has a linear expansion coefficient larger than that of the substrate (L), and the difference of linear expansion coefficient is 5×10cm/cm/°C or more. The shape holding layer contains a thermoplastic polymer having a softening point of 110°C or higher, and the difference of linear expansion coefficient between the shape holding layer and the substrate (H) is 160×10cm/cm/°C or less.

Description

  The present invention relates to an organic EL device and a method for manufacturing the organic EL device.

  The organic EL device is expected as a flat panel display because of advantages such as a wide viewing angle, a high response speed, and low power consumption. An organic EL device has an organic light emitting medium layer sandwiched between two transparent electrodes, and the organic light emitting medium layer emits light by injecting current from both electrodes.

  Since the total thickness of the two electrodes and the organic light emitting medium layer sandwiched between them is a thin film of about several hundreds of nanometers, the thickness of the organic EL device is the thickness of the substrate and the surface sealing for sealing the organic EL element. It can be formed only from the thickness of the stopper. Therefore, it is expected to be applied to small and thin displays such as mobile phones that are expected to be thin and lightweight, backlight members, flexible displays based on flexible plastics, and the like.

  However, when an organic EL device is made thin, warping of the organic EL device becomes remarkable. Therefore, in order to prevent warpage of the organic EL device, it has been proposed to bond a warpage prevention layer or an anti-curl layer to the substrate of the organic EL device via an adhesive layer (see Patent Documents 1 and 2). .

JP 2003-317937 A JP 2009-81123 A

  An organic EL device has a pair of substrates (for example, a circuit substrate and a display substrate) and a surface sealing material, but the difference between the linear expansion coefficient of the circuit substrate and the linear expansion coefficient of the display substrate may be large. For this reason, in the step of thermally curing the surface sealing material, warping or distortion occurs in the element due to the difference in the degree of expansion / contraction between the substrates and the curing of the sealing material. An object of the present invention is to provide an organic EL device with less warping even if the difference in linear expansion coefficient between a circuit board and a display substrate is large.

That is, the first of the present invention relates to the following organic EL device.
[1] A substrate (H), a surface sealing material, a substrate (L), and a shape retention layer are included in this order, and an organic EL element is disposed on the substrate (H) or the substrate (L). An organic EL device,
The linear expansion coefficient of the base material (L) is smaller than the linear expansion coefficient of the base material (H), and the linear expansion coefficient of the base material (H) and the linear expansion coefficient of the base material (L) And a difference of 5 × 10 ⁻⁶ cm / cm / ° C. or more,
The shape retention layer contains a thermoplastic polymer having a softening point of 110 ° C. or higher, and the difference between the linear expansion coefficient of the shape retention layer and the linear expansion coefficient of the substrate (H) is 160 × 10 ⁻⁶ cm / cm / An organic EL device having a temperature of ℃ or lower.
[2] The organic EL device according to [1], wherein the surface sealing material is a cured product of a thermosetting resin composition, and a curing temperature of the thermosetting resin composition is 50 to 150 ° C.
[3] The organic EL device according to [1] or [2], wherein the surface sealing material includes a cured product of one or more kinds of resins selected from the group consisting of epoxy resins and silicone resins.
[4] The thermoplastic polymer is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyamide, polycarbonate, polypropylene (PP), and polybutylene terephthalate (PBT). The organic EL device according to any one of [1] to [3], which is one or more selected resins.
[5] The organic EL device according to any one of [1] to [4], wherein the base material (H) has a linear expansion coefficient of 20 × 10 ^{−6 to} 180 × 10 ⁻⁶ cm / cm / ° C.
[6] The substrate (H) is one or more selected from the group consisting of aluminum, ester (co) polymers, cyclic olefin (co) polymers, and 4-methyl-1-pentene (co) polymers. The organic EL device according to any one of [1] to [5], comprising a polymer.
[7] The organic EL device according to any one of [1] to [6], wherein the base material (L) has a linear expansion coefficient of 1 × 10 ^{−6 to} 100 × 10 ⁻⁶ cm / cm / ° C.
[8] The organic EL device according to any one of [1] to [7], wherein the substrate (L) is glass, silicon, ester (co) polymer, polyimide, polycarbonate, or polyamide.

The second of the present invention relates to a method for producing an organic EL device shown below.
[9] A substrate (H), a thermosetting resin composition, a substrate (L), and a shape retention layer are included in this order, and an organic EL element is disposed on the substrate (H) or the substrate (L). A method for producing an organic EL device, comprising: a first step of preparing a structured body; and a second step of thermosetting the thermosetting resin composition,
The linear expansion coefficient of the base material (L) is smaller than the linear expansion coefficient of the base material (H), and the linear expansion coefficient of the base material (H) and the linear expansion coefficient of the base material (L) difference between is not less ^{5 × 10 -6 cm / cm /} ℃ or higher, the shape-retaining layer comprises a thermoplastic polymer above the softening point of 110 ° C., and the shape-retaining layer linear expansion coefficient between the base material (H ) Of the linear expansion coefficient is 160 × 10 ⁻⁶ cm / cm / ° C. or less.

The third of the present invention relates to the organic EL panel shown below.
[10] An organic EL panel comprising the organic EL device according to any one of [1] to [8].

  When the organic EL device of the present invention seals the organic EL element by thermosetting the surface sealant in spite of the difference between the linear expansion coefficients of the pair of substrates constituting the organic EL device being not less than a certain value. Warpage of the organic EL device is suppressed.

It is a figure explaining a mode that curvature generate | occur | produces in the conventional organic EL device. It is a figure explaining the mechanism which suppresses generation | occurrence | production of the curvature of the organic EL device of this invention.

  The organic EL device of the present invention includes a base material (H), an organic EL element, a surface sealing material that is a cured thermosetting resin that covers the organic EL element, a base material (L), and a shape maintaining layer. And have.

1. Substrate (H) The substrate (H) is a member on which an organic EL element can be disposed. Although a base material (H) may be transparent or non-transparent, it is transparent when taking out the light from an organic light emitting layer through a base material (H).

The linear expansion coefficient of the base material (H) may be larger than the linear expansion coefficient of the base material (L), specifically, 5 × 10 ⁻⁶ cm / cm higher than the linear expansion coefficient of the base material (L). It may be larger than / ° C.

Further, the difference between the linear expansion coefficient of the substrate (H) and the linear expansion coefficient of the shape-retaining layer is 160 × 10 ⁻⁶ cm / cm / ° C. or less, preferably 100 × 10 ⁻⁶ cm / cm / ° C. Hereinafter, 50 × 10 ⁻⁶ cm / cm / ° C. or less is more preferable. Either the linear expansion coefficient of the substrate (H) or the linear expansion coefficient of the shape-retaining layer may be larger.

The linear expansion coefficient of the substrate (H) is preferably 20 × 10 ⁻⁶ cm / cm / ° C. to 180 × 10 ⁻⁶ cm / cm / ° C. The measurement of the linear expansion coefficient of a base material (H) is based on ASTM E-831, for example, can be measured by TMA method. Let the linear expansion coefficient of a base material (H) be the average value of the linear expansion coefficient in the range of 25-100 degreeC.

  The thickness of the substrate (H) is preferably 5 to 300 μm. Moreover, it is preferable that the tensile elasticity modulus of a base material (H) is 10-500 Mpa.

  The specific material of the substrate (H) is not particularly limited, but is preferably an aluminum foil or an organic polymer; examples of preferable organic polymers include ester (co) polymers, cyclic olefin (co) polymers, One or more polymers selected from the group consisting of 4-methyl-1-pentene (co) polymers are included. The (co) polymer referred to in the present application includes both homopolymers and copolymers. Specifically, the 4-methyl-1-pentene (co) polymer is a copolymer of 4-methyl-1-pentene, which is a homopolymer of 4-methyl-1-pentene, and 4-methyl-1-pentene. It includes both polymerizable compounds, such as copolymers with α-olefins.

2. About organic EL element The shape and material of an organic EL element should just be an organic EL element normally used, and are not specifically limited. The organic EL element is disposed on the substrate (H) or the base material (L), and is usually disposed on the base material (L) which is not easily thermally deformed to form an electrode layer or the like described later. An organic EL element is formed by laminating one electrode layer, an organic EL layer, and the other electrode layer from the substrate (L) side. One electrode layer is, for example, an anode transparent electrode layer (made of ITO, IZO, or the like), and the other electrode layer is, for example, a cathode reflective electrode layer (made of aluminum, silver, or the like). The electrode layer and the organic EL layer may be formed by vacuum deposition, sputtering, or the like.

  The organic EL device may include a functional layer other than the organic EL layer; examples of the other functional layer include a hole transport layer, a hole injection layer, an electron transport layer, and an electron injection layer. It is. The organic EL element may be a top emission type or a bottom emission type.

3. About surface sealing material A surface sealing material is a member which covers the organic EL element arrange | positioned at a base material, normally a base material (L), Comprising: It consists of hardened | cured material of a thermosetting resin composition. The thermosetting resin composition is preferably an epoxy resin composition or a silicone resin composition, and more preferably an epoxy resin composition. When extracting light from the organic light emitting layer through the substrate (L), the surface sealing material is required to have high transparency.

  The epoxy resin composition constituting the thermosetting resin composition includes (A) a composition containing a high molecular weight epoxy resin and (B) a curing accelerator, and (C) a low molecular weight epoxy resin and (B) curing. A composition comprising an accelerator is preferred, and may optionally contain (D) a silane coupling agent, (E) a solvent, and other components, (A) a high molecular weight epoxy resin and (C) low Compositions containing both molecular weight epoxy resins can also be used.

(A) High molecular weight epoxy resin The (A) high molecular weight epoxy resin that can be contained in the thermosetting resin composition is an epoxy resin having a weight average molecular weight of 2 × 10 ³ to 1 × 10 ⁵ , and has a weight. The average molecular weight is preferably 3 × 10 ³ to 8 × 10 ⁴ , more preferably 4 × 10 ^{3 to} 6 × 10 ⁴ . The weight average molecular weight can be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance under the following conditions.
Equipment: GPC-101, manufactured by SHODEX
Developing solvent: Tetrahydrofuran Standard polystyrene: PS-1 made by VARIAN (molecular weight 580-7,500,000), PS-2 made by VARIAN (molecular weight 580-377,400)

(A) The epoxy equivalent of the high molecular weight epoxy resin is preferably 500 to 1 × 10 ⁴ g / eq, more preferably 600 to 9000 g / eq, considering the crosslinking density of the epoxy resin composition. preferable.

  (A) Preferred examples of the high molecular weight epoxy resin include a resin containing a bisphenol skeleton in the main chain because low moisture permeability can be realized. More preferably, bisphenol and epichlorohydrin are monomers. A resin contained as a component, more preferably an oligomer thereof.

  (A) Although all the monomer components of the high molecular weight epoxy resin may be bisphenol and epichlorohydrin; some of the monomer components may be compounds (comonomer components) other than bisphenol and epichlorohydrin. Examples of the comonomer component include dihydric or higher polyhydric alcohols (for example, divalent phenol and glycol). By using a part of the monomer component as a compound (comonomer component) other than bisphenol and epichlorohydrin, the molecular weight can be controlled to a desired value.

(A) Preferred examples of the high molecular weight epoxy resin include a resin having a repeating structural unit represented by the following general formula (1).

In the general formula (1), X represents a single bond, a methylene group, an isopropylidene group, —S— or —SO ₂ —. In the general formula (1), the structural unit in which X is a methylene group is a bisphenol F type structural unit; the structural unit in which X is an isopropylidene group is a bisphenol A type structural unit. n is the repeating number of the structural unit represented by the general formula (1), and is an integer of 2 or more.

In the general formula (1), P is the substitution number of the substituents _{R 1,} is an integer of 0-4. From the viewpoint of heat resistance and low moisture permeability, P is preferably 0. Each R ₁ is independently an alkyl group having 1 to 5 carbon atoms, and is preferably a methyl group.

  A bisphenol F-type repeating structural unit in which X in the general formula (1) is a methylene group and a bisphenol A-type repeating structural unit in which X in the general formula (1) is an isopropylidene group are contained in one molecule. More preferred are oligomers. When the oligomer contains a bisphenol A-type repeating structural unit, the viscosity of the high molecular weight epoxy resin composition can be increased. On the other hand, the steric hindrance is reduced when the oligomer contains a repeating structural unit of the bisphenol F type. Thereby, a some phenylene group becomes easy to orientate and the water vapor transmission rate of the hardened | cured material of an epoxy resin composition can be made low.

  Bisphenol F-type repeating structure contained in one molecule relative to the total number of bisphenol A-type repeating structural units (A) and bisphenol F-type repeating structural units (F) contained in one molecule of the oligomer The ratio of the number of units (F); {(F / A + F) × 100} is preferably 50% or more, and more preferably 55% or more. By including many bisphenol F-type repeating structural units, the moisture permeability of the cured product of the epoxy resin composition can be reduced.

  (A) Content of high molecular weight epoxy resin is 100-2000 with respect to 100 mass parts in total of (B) hardening accelerator mentioned later, (C) low molecular weight epoxy resin, and (D) silane coupling agent. It is preferable to set it as a mass part, More preferably, it is 210-2000 mass part, More preferably, it is 250-1200 mass part. (A) If the content ratio of the high molecular weight epoxy resin is too high, the fluidity of the composition at the time of thermocompression bonding to the heat-bonded material is lowered, so that a gap is easily formed between the materials. On the other hand, when the content ratio of the (A) high molecular weight epoxy resin is too low, not only the shape retention of the epoxy resin composition containing it is low, but also the moisture resistance of the cured product is low.

  Moreover, when an epoxy resin composition contains the below-mentioned (C) low molecular weight epoxy resin, content of (A) high molecular weight epoxy resin is with respect to 100 mass parts of (C) low molecular weight epoxy resin. 100 to 1500 parts by mass, more preferably 120 to 1200 parts by mass. (C) By setting the content ratio of the low molecular weight epoxy resin and (A) high molecular weight epoxy resin in the above range, the epoxy resin composition does not decrease the fluidity when thermocompression bonding to the heat-bonded material. The shape stability of the product can be increased, and a cured product with low moisture permeability can be provided.

(B) Hardening accelerator The hardening accelerator contained in the epoxy resin composition which comprises a thermosetting resin composition has the function to accelerate hardening while starting hardening of an epoxy resin. Examples of the curing accelerator include imidazole compounds, amine compounds, and acid anhydrides. Examples of imidazole compounds include 2-ethyl-4-methylimidazole and the like; examples of amine compounds include trisdimethylaminomethylphenol and the like. Examples of acid anhydrides include aromatic acid anhydrides that are colored, and therefore aliphatic (aromatic hydrogenated) acid anhydrides are preferred. Examples of acid anhydrides contained in the sealant include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, trimellitic anhydride, hexachloroendomethylenetetrahydrophthalic anhydride, benzophenone tetracarboxylic anhydride, etc. It is. An aliphatic acid anhydride having high transparency is hexahydrophthalic anhydride or methylhexahydrophthalic anhydride. (B) The curing accelerator may be a Lewis base compound.

  (B) The molecular weight of the curing accelerator is preferably 80 to 800, more preferably 100 to 500, and still more preferably 120 to 250. (B) When the molecular weight of the curing accelerator is less than 80, the volatility becomes high, and bubbles may be generated in the epoxy resin composition when the epoxy resin composition is thermally cured. On the other hand, when the molecular weight is more than 800, the flowability of the epoxy resin composition may decrease when the epoxy resin composition is thermally cured, and the diffusibility of the curing accelerator in the epoxy resin composition may further decrease. It may be difficult to obtain sufficient curability.

  (B) Content of hardening accelerator is 0.1-100 mass parts with respect to a total of 100 mass parts of (A) high molecular weight epoxy resin and the below-mentioned (C) low molecular weight epoxy resin. preferable. In particular, when an acid anhydride is added, it is preferable to adjust the equivalent ratio of “acid anhydride group / epoxy group” to 0.8 to 1.2 from the viewpoint of curability and the like. On the other hand, when the curing accelerator is an imidazole compound or an amine compound, 0.1 to 5 parts per 100 parts by mass in total of (A) high molecular weight epoxy resin and (C) low molecular weight epoxy resin described later. If it is within the range of parts by mass, the transparency becomes higher, which is preferable.

(C) Low molecular weight epoxy resin It is preferable that the epoxy resin composition which comprises a thermosetting resin composition contains (C) low molecular weight epoxy resin. (C) The low molecular weight epoxy resin is an epoxy resin having a weight average molecular weight of 100 to 1200, and preferably a weight average molecular weight of 200 to 1100. The weight average molecular weight is measured in the same manner as described above. By blending the epoxy resin composition with a low molecular weight epoxy resin having a weight average molecular weight in the above range, the fluidity of the epoxy resin composition when thermosetting the epoxy resin composition can be enhanced. The adhesion to the heat-bonded material can be improved.

  (C) The epoxy equivalent of the low molecular weight epoxy resin is preferably 80 to 300 g / eq, and more preferably 100 to 200 g / eq. The amount of hydrogen bonding of the epoxy resin composition containing the low molecular weight epoxy resin having an epoxy equivalent weight within the above range is increased.

  (C) The low molecular weight epoxy resin is preferably a phenol type epoxy resin, and more preferably a divalent or higher valent epoxy type compound or an oligomer containing a phenol derivative and epichlorohydrin as monomer components. .

Examples of the bivalent or higher phenol type epoxy compound include a bisphenol type epoxy compound, a phenol novolac type epoxy compound, a cresol novolak type epoxy compound, and the like. Examples of the bisphenol type epoxy compound include a compound represented by the general formula (2). X in following general formula (2), _{R 1} and p are the same as X, _{R 1} and P in the general formula (1).

  Examples of oligomeric phenol derivatives containing a phenol derivative and epichlorohydrin as monomer components include bisphenol, hydrogenated bisphenol, phenol novolac, cresol novolac, and the like.

  (C) Preferred examples of the low molecular weight epoxy resin include a bisphenol type epoxy compound or an oligomer having bisphenol and epichlorohydrin as monomer components. More preferably, in the general formula (1), the number of repetitions is as follows. n is an oligomer having 2-4. Such an oligomer has a high affinity with a high molecular weight epoxy resin. (C) The repeating structural unit contained in the low molecular weight epoxy resin may be the same as or different from the repeating structural unit contained in the (A) high molecular weight epoxy resin.

  (C) The content of the low molecular weight epoxy resin is 1 to 100 parts by mass with respect to 100 parts by mass in total of (A) high molecular weight epoxy resin, (B) curing accelerator, and (D) silane coupling agent. Is preferable, and more preferably 5 to 50 parts by mass. (C) By making the content rate of a low molecular weight epoxy resin into the said range, the fluidity | liquidity of the composition when thermosetting an epoxy resin composition is improved, and also the sclerosis | hardenability of an epoxy resin composition can also be made favorable.

(D) Silane coupling agent The silane coupling agent may be contained in the epoxy resin composition which comprises a thermosetting resin composition. The silane coupling agent is preferably 1) a silane coupling agent having an epoxy group, or 2) a silane coupling agent having a functional group capable of reacting with an epoxy group. Reacting with an epoxy group means an addition reaction with an epoxy group. An epoxy resin composition containing a silane coupling agent has high adhesion to the substrate when used as a surface sealing agent for organic EL. Moreover, the silane coupling agent which has an epoxy group or has a functional group which can react with an epoxy group reacts with the epoxy resin in an epoxy resin composition. Therefore, the silane coupling agent is also preferable in that a low molecular weight component does not remain in the cured product of the sheet-like epoxy composition.

  1) The silane coupling agent having an epoxy group is a silane coupling agent containing an epoxy group such as a glycidyl group. Examples thereof include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxy). (Cyclohexyl) ethyltrimethoxysilane and the like.

  2) Functional groups capable of reacting with epoxy groups include amino groups such as primary amino groups and secondary amino groups; carboxyl groups and the like, and groups that can be converted into functional groups capable of reacting with epoxy groups (for example, Methacryloyl group, isocyanate group, etc.). Examples of the silane coupling agent having a functional group capable of reacting with such an epoxy group include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3- Aminopropylmethyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- ( 1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane or 3- (4-methylpiperazino) propyltrimethoxysilane, trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, And γ-isocyanatopropyltriethoxysilane Etc. are included.

  Other silane coupling agents can also be included. Examples of other silane coupling agents include vinyltriacetoxysilane and vinyltrimethoxysilane. One of these silane coupling agents may be used alone, or two or more thereof may be used in combination.

  The molecular weight of the silane coupling agent is preferably 80 to 800. If the molecular weight of the silane coupling agent exceeds 800, the fluidity when thermocompression bonding the epoxy resin composition is lowered, and the adhesion may be lowered.

  The content of the silane coupling agent is preferably 0.05 to 30 parts by mass, more preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the epoxy resin composition, and 0.3 More preferably, it is 10 mass parts.

(E) Solvent The epoxy resin composition constituting the thermosetting resin composition may contain a solvent from the viewpoint of uniformly mixing the components (A) to (D) described above. The solvent particularly has a function of uniformly dispersing or dissolving the high molecular weight epoxy resin. The solvent may be various organic solvents, aromatic solvents such as toluene and xylene; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ether, dibutyl ether, tetrahydrofuran, dioxane, ethylene glycol monoalkyl ether, Ethers such as ethylene glycol dialkyl ether, propylene glycol or dialkyl ether; aprotic polar solvents such as N-methylpyrrolidone, dimethylimidazolidinone and dimethylformaldehyde; esters such as ethyl acetate and butyl acetate It is. In particular, a ketone solvent (a solvent having a keto group) such as methyl ethyl ketone is more preferable because it easily dissolves a high molecular weight epoxy resin.

(F) Other optional components The epoxy resin composition constituting the thermosetting resin composition further contains optional components such as other resin components, fillers, modifiers, stabilizers and the like within a range not impairing the effects of the invention. can do. Examples of other resin components include polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene-styrene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine series Oligomer, silicon oligomer and polysulfide oligomer are included. These 1 type can be contained individually or in combination of multiple types.

  Examples of the filler include glass beads, styrene polymer particles, methacrylate polymer particles, ethylene polymer particles, and propylene polymer particles. The filler may be a combination of a plurality of types.

  Examples of the modifier include polymerization initiation aids, anti-aging agents, leveling agents, wettability improvers, surfactants, plasticizers, and the like. You may use these in combination of multiple types. Examples of the stabilizer include ultraviolet absorbers, preservatives, and antibacterial agents. The modifier may be a combination of a plurality of types.

(Curability of thermosetting resin composition)
The curing rate of the thermosetting resin composition is preferably higher to some extent. This is to improve workability when bonding to the heat-bonded material. “Cure quickly” means, for example, curing within 120 minutes under heating conditions (50 to 100 ° C.).

  Whether or not the thermosetting resin composition has been cured may be determined by confirming whether or not the resin composition has been gelled by curing on a hot plate. Whether the resin composition is cured may be determined from the conversion rate of the epoxy group. The conversion rate of the epoxy group can be determined from the reduction rate of the epoxy group in the IR spectrum by measuring the IR spectrum of the resin composition before the curing reaction and after the curing reaction. The curability of the resin composition is controlled by adjusting the content of the curing accelerator.

  The curing temperature of the thermosetting resin composition is not particularly limited as long as it is a temperature at which the organic EL element to be sealed is not easily deteriorated, and can be appropriately set or is usually 50 to 150 ° C., 60 It is often set in a range of ˜130 ° C.

  Although the thickness of the surface sealing material of the surface sealing material of the organic EL device of this invention is not specifically limited, For example, it is 1-100 micrometers.

The linear expansion coefficient of the surface sealing material is preferably in the range of 10 to 200 × 10 ⁻⁶ cm / cm / ° C. When there is a linear expansion coefficient in the range, the cured product of the surface sealing agent and the substrate are difficult to peel off.

  The surface sealing material of the organic EL device of the present invention is a cured product of a thermosetting resin composition. Typically, the thermosetting resin composition is disposed so as to cover the organic EL element disposed on the substrate (L), and the laminate obtained by further laminating the base material (H) and the shape retention layer. The body is obtained by heating at the curing temperature of the thermosetting resin composition. The curing temperature is preferably 50 to 100 ° C. If the thermosetting resin composition is to be cured at a temperature higher than 100 ° C., the workability deteriorates, so that a gap is easily formed, or the organic EL element is adversely affected by heating. On the other hand, if the thermosetting resin composition is cured at a temperature lower than 50, the curing may be insufficient.

4). About base material (L) A base material (L) is a base material laminated | stacked on the surface sealing material in the organic EL device. The linear expansion coefficient of the base material (L) is lower than the linear expansion coefficient of the base material (H), more specifically, 5 × 10 ⁻⁶ cm / cm / ° C. than the linear expansion coefficient of the base material (H). More than low. The linear expansion coefficient of the substrate (L) is preferably in the range of 1 × 10 ⁻⁶ cm / cm / ° C. to 100 × 10 ⁻⁶ cm / cm / ° C., and 5 × 10 ⁻⁶ cm / cm / ° C. More preferably, it is in the range of ˜30 × 10 ⁻⁶ cm / cm / ° C.

  Although the specific material of the substrate (L) is not particularly limited, it is preferably an inorganic substance, such as an inorganic substance such as glass or silicon, an ester copolymer (PET, PEN, PBT, etc.), polyimide, polycarbonate, Resins such as polyamide are exemplified. The thickness of the substrate (L) is preferably 0.1 to 1 mm from the viewpoint of thinning and durability of the organic EL device.

5. About shape retention layer A shape retention layer is a member laminated | stacked on the base material (L), and the shape retention layer and the base material (L) may be affixed through the adhesion layer or the contact bonding layer. In addition, only a shape retention layer or a film including a shape retention layer and an adhesive layer or an adhesive layer is also referred to as a “shape retention film”.

The difference between the linear expansion coefficient of the shape retention layer and the linear expansion coefficient of the substrate (H) is preferably 160 × 10 ⁻⁶ cm / cm / ° C. or less. When it is in the above range, the warp of the organic EL device caused by thermosetting can be suppressed by a warp suppressing mechanism described later.

  The shape retention layer contains a thermoplastic polymer; the softening point of the thermoplastic polymer is preferably equal to or higher than the curing temperature of the aforementioned thermosetting resin, and is usually preferably 110 ° C. or higher. Examples of thermoplastic polymers contained in the shape-retaining layer include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyamide, polycarbonate, polypropylene (PP) and polybutylene terephthalate (PBT). ) Etc. are included.

  The thickness of the shape-retaining layer is 100 to 500 μm from the viewpoint of thinning the organic EL device and workability when the shape-retaining layer is bonded to the substrate (L), and from suppressing warpage and distortion of the device. It is preferable.

  As above-mentioned, the shape retention layer and the base material (L) may be affixed through the adhesion layer or the contact bonding layer. Examples of the adhesive layer include polyvinyl alcohol adhesives, acrylic adhesives, polyester adhesives, epoxy adhesives, and the like.

Manufacturing method of organic EL device The manufacturing method of the organic EL device of the present invention is a main surface side of a base material (L) on which a thermosetting resin composition and an organic EL element which are cured and become a surface sealing material are not disposed. The above-mentioned shape retention layer is disposed, and the substrate (H), the thermosetting resin composition, the substrate (L), and the shape retention layer are included in this order, and the substrate (H) or substrate (L ) After preparing the structure on which the organic EL element is disposed, the method includes heating the structure to cure the thermosetting resin composition that becomes the surface sealing material.

  In the manufacturing method of the organic EL device of the present invention, the organic EL element is not disposed or is not planned to be disposed before curing the thermosetting resin composition that is cured to be a surface sealing material. The shape retention layer described above may be disposed on the main surface side of the material (L). Specifically, the following methods can be considered. 1) After placing the shape-retaining layer on the substrate (L), the organic EL element is placed on the substrate (L). 2) After the organic EL element is placed, the shape-retaining layer is placed on the substrate (L). 3) After the organic EL element is disposed and cured and covered with a thermosetting resin composition that becomes a surface sealing material, the organic EL element of the substrate (L) is not disposed. 4) The organic EL element is disposed on the surface side, and the organic EL element is covered with a thermosetting resin composition that is cured and becomes a surface sealing material. Is prepared, and then “a base material (H), a thermosetting resin composition serving as a surface sealing material, an organic EL element, a laminate of the base material (L)” is prepared, and then the base material (L) is prepared. A shape retention layer is disposed.

  Among these, from the viewpoint of production efficiency and the like, a first step of forming an organic EL element on the substrate (L) and a thermosetting resin composition that cures the organic EL element to become a surface sealant. The second step of covering and the base material (H) are overlapped in order of the base material (H), the thermosetting resin composition covering the organic EL element, the organic EL element, and the base material (L). 3 and the 4th process of sticking the shape maintenance film which has a shape maintenance layer on the principal surface side in which the organic EL element of a substrate (L) is not formed, and thermosetting the thermosetting resin composition The manufacturing method of an organic EL device including the fifth step is preferable. In particular, a method of covering the organic EL element after laminating the base material (H) and the thermosetting resin composition sheet is preferable.

Regarding the warpage suppression of the organic EL device of the present invention The organic EL device of the present invention is a thermosetting resin that is thermoset despite the large difference in the linear expansion coefficient between the substrate (H) and the substrate (L). When the surface sealing material is formed, warpage of the organic EL device is suppressed.

  This warpage suppressing mechanism will be described with reference to FIGS. 1A to 1C and FIGS. 1A to 1C are diagrams showing a process for manufacturing an organic EL device in which a substrate (H), a surface sealing material made of a cured product of a thermosetting resin composition layer, and a substrate (L) are laminated. is there. 2A to C, a substrate (H), a surface sealing material made of a cured product of a thermosetting resin composition layer, a substrate (L), an adhesive layer or an adhesive layer, and a shape maintaining layer are laminated. It is a figure which shows the process which manufactures another organic EL device. 1A to 1C and 2A to 2C, the organic EL element is omitted.

  FIG. 1A shows a laminate in which a substrate (H), an uncured thermosetting resin composition layer, and a substrate (L) are laminated. An organic EL element is disposed between the substrate (H) and the substrate (L), but is omitted in FIG. 2A. Let D1 be the thickness of the uncured thermosetting resin composition layer. Further, the width of the laminated body is L1.

  FIG. 1B is a diagram showing a state in which the laminate shown in FIG. 1A is heated to cure the uncured thermosetting resin composition layer. Since the base material (H) has a large expansion rate, the base material (H) expands during heating, and its width becomes L2. On the other hand, since the expansion coefficient of the substrate (L) is low, the base material (L) is less likely to expand during heating, and its width L1 'does not change much from L1. The thickness of the thermosetting resin composition layer is D2 (D2 <D1), and the side length of the thermosetting resin composition layer is D3 (D1 <D3).

  FIG. 1C is a diagram illustrating a state in which the stacked body heated in FIG. 1B is cooled. Since the cured thermosetting resin composition tends to maintain its shape, the laminate is warped with the central portion of the substrate (H) as a recess. Thus, the conventional organic EL device may be warped.

  In contrast, in FIG. 2A, a substrate (H), an uncured thermosetting resin composition layer, a substrate (L), an adhesive layer or an adhesive layer, and the shape-retaining layer of the present invention are laminated. The resulting laminate is shown. Further, an organic EL element is disposed between the substrate (H) and the substrate (L), but is omitted in FIG. 2A. Let D1 be the thickness of the uncured thermosetting resin composition layer. Further, the width of the laminated body is L1.

  FIG. 2B is a diagram showing a state in which the laminate shown in FIG. 2A is heated to cure the uncured thermosetting resin composition layer. Since the base material (H) has a large expansion rate, the base material (H) expands during heating, and its width becomes L2. Similarly, since the expansion rate of the shape retention layer is close to the expansion rate of the substrate (H), the shape retention layer also expands during heating and its width increases. Further, the thickness of the thermosetting resin composition layer is D2 (D2 <D1), and the side length D3 of the thermosetting resin composition layer is (D1 <D3). On the other hand, since the expansion coefficient of the substrate (L) is low, the base material (L) is less likely to expand during heating, and its width L1 'does not change much from L1.

  FIG. 2C is a diagram illustrating a state in which the laminated body heated in FIG. 2B is cooled. By cooling, the substrate (H) shrinks and its width tends to return from L2 to L1, so the laminate of the substrate (H) / sealant (cured) / substrate (L) is the center of the substrate (H). Stress A is generated to warp so that the portion becomes a recess.

  On the other hand, since the shape retention layer contracts by cooling and the width thereof tends to be reduced, a stress B is generated which tends to warp so that the central portion of the substrate (L) becomes a concave portion. The present invention is characterized in that the stress A is canceled out by the stress B. That is, when the stress A is offset by the stress B, the cured thermosetting resin composition layer is deformed, the thickness returns to D1, and the organic EL device is not warped.

  The organic EL device of the present invention can be a member of an organic EL panel. The organic EL panel includes: a substrate on which an organic EL element is disposed; a substrate that is paired with a display substrate; a surface sealing material that is interposed between the display substrate and the counter substrate and seals the organic EL element. Have. A surface sealing material in which a space formed between an organic EL element and a sealing substrate is filled is referred to as a surface sealing type organic EL panel.

(Synthesis Example 1)
Prime Polypro F107BV (Prime Polymer Co., Ltd. polypropylene) was prepared as a raw material for the shape retention layer. As a raw material of an adhesive layer, the brand name NOTIO PN3560 (Mitsui Chemicals Co., Ltd. make, MFR4g / 10min (ASTM D1238 conformity, measurement temperature 230 degreeC) was prepared.

Method for forming co-pressing pressure-sensitive adhesive layer The raw materials for the shape-retaining layer and the pressure-sensitive adhesive layer were introduced into each extruder equipped with a full-flight screw and melt-kneaded. A two-layer structure in which the extrusion temperature of the shape-retaining layer and the pressure-sensitive adhesive layer is 230 ° C., two layers of molten resin are laminated in a multi-layer die and co-extruded, and the shape-retaining layer and the pressure-sensitive adhesive layer are sequentially laminated. A film was obtained. A separator (manufactured by Tosero Co., Ltd., trade name SP-PET) was further laminated on the pressure-sensitive adhesive layer of the obtained laminated film, and then slit and wound into a predetermined width to produce a shape-retaining film F4.
(Synthesis Example 2)
<Method for synthesizing adhesive layer>
150 parts by weight of deionized water in a polymerization reactor, 0.5 part by weight of 4,4′-azobis-4-cyanovaleric acid [manufactured by Otsuka Chemical Co., Ltd., trade name: ACVA] as a polymerization initiator, acrylic acid 52.25 parts by weight of butyl, 25 parts by weight of methyl methacrylate, 15 parts by weight of methacrylic acid-2-hydroxyethyl, 6 parts by weight of methacrylic acid, 1 part by weight of acrylamide, polyoxyethylene nonylphenyl ether (of ethylene oxide) as a water-soluble comonomer An average value of the added mole number; about 20) In which a polymerizable 1-propenyl group is introduced into a benzene ring of an ammonium salt of a sulfate ester [Daiichi Kogyo Seiyaku Co., Ltd .: trade name: Aqualon HS-20] 0 .75 parts by weight was added, and emulsion polymerization was carried out at 70 ° C. for 9 hours with stirring to obtain an acrylic resin water emulsion. This was neutralized with 14 wt% aqueous ammonia to obtain an adhesive polymer emulsion (adhesive main ingredient) containing 40 wt% solid content. 100 parts by weight of the resulting pressure-sensitive adhesive main agent emulsion (pressure-sensitive adhesive polymer concentration: 40% by weight) was collected, and further adjusted to pH 9.3 by adding 14% by weight aqueous ammonia. Next, a pressure-sensitive adhesive coating is prepared by adding 4.0 parts by weight of an aziridine-based cross-linking agent [trade name: Chemitite PZ-33, manufactured by Nippon Shokubai Chemical Co., Ltd.] and 5 parts by weight of diethylene glycol monobutyl ether. A liquid was obtained.

<Method for producing base film>
Polyester-based stretched film [manufactured by Toyobo Co., Ltd., trade name: Toyobo Ester Film, brand: E7180, thickness: 50 μm] is selected, and ethylene-vinyl acetate having a thickness of 70 μm as a low elastic modulus resin layer on one surface thereof Copolymer (Mitsui / Dupont Polychemical Co., Ltd., brand: EVAFLEX P-1905 (EV460) film was laminated. In this case, in order to increase the adhesion between the layers of these multilayer films, corona discharge was applied to both layers. The surface of the ethylene-vinyl acetate copolymer film on which the pressure-sensitive adhesive layer is formed was subjected to corona discharge treatment.

<Adhesion method of adhesive layer and substrate film>
The adhesive coating solution of (Synthesis Example 2) is applied to the die coater on the surface on which the release treatment of the 38 μm thick polyethylene terephthalate film (release film) having a silicone treatment (release treatment) on one surface is performed. And dried to form an adhesive layer having a thickness of 10 μm. The surface of the base film on the side subjected to the corona treatment was bonded and pressed by a dry laminator, and the pressure-sensitive adhesive layer was transferred to the surface on the side subjected to the corona treatment. After the transfer, the film was heated at 60 ° C. for 48 hours, and then cooled to room temperature to obtain a shape-retaining film F5.

  An epoxy resin varnish (epoxy A) having the following composition was prepared. To the flask, 0.8 parts by mass of jER4005P (Mitsubishi Chemical Co., Ltd.), 0.2 parts by mass of YL983U (weight average molecular weight 398, manufactured by Mitsubishi Chemical Co., Ltd.), and 0.43 parts by mass of methyl ethyl ketone were added. Dissolved with stirring. To this solution, 0.001 part by weight of KBM-403 (3-glycidoxypropyltrimethoxysilane, molecular weight 236, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.01 part by weight of IBMI 12 (manufactured by Mitsubishi Chemical Corporation) were added. Then, the mixture was stirred at room temperature to prepare an epoxy resin composition (solid content concentration 70% by mass).

  The prepared epoxy resin composition was coated on a PET film (Purex A53, Teijin DuPont Films, Inc., 38 μm), which was release-treated using a coating machine, so that the dry thickness was 40 μm. It dried at 40 degreeC for 2 hours, and obtained the solid sheet-like epoxy resin composition at room temperature (about 25 degreeC). Furthermore, a PET film (Purex A31 manufactured by Teijin DuPont Films, Ltd.) subjected to release treatment as a protective film was thermocompression bonded onto the sheet-like epoxy resin composition to obtain a sealing sheet. In addition, a protective film is peeled off suitably and the sheet-like epoxy resin composition surface is exposed and used.

A glass substrate (Matsunami cover glass, 50 × 70 mm, thickness No. 1 (150 μm)) was used as the base material (L). A 50 nm SiO ₂ film was formed by sputtering on one surface of a cycloolefin polymer sheet (Zeonor film ZF14, manufactured by Nippon Zeon Co., Ltd., 100 μm) to obtain a substrate (H). Sputter deposition of SiO ₂ film is carried out by placing a SiO ₂ target on a sputtering thin film forming apparatus (ULVAC, model JSP-8000) and pre-sputtering (condition: gas Ar (15 sccm), 4.7 × 10 ⁻¹ ). Pa, RF output 300 W, time 120 seconds, room temperature), and then sputter deposition (conditions: gas Ar (15 sccm), 4.7 × 10 ⁻¹ Pa, RF output 300 W, time 2500 seconds, room temperature) .

In accordance with the laminated structure shown in Table 2 and Table 3, glass substrate (thickness 150 μm) / sheet-shaped epoxy resin composition (thickness 40 μm) / substrate (H) as shape retention layer / substrate (L) Was obtained in this order. To increase the adhesive strength where the substrate (H) a sheet-like epoxy resin composition, bonding the side formed by laminating a SiO ₂ film of the base material (H) in a sheet-like epoxy resin composition. In Example 4, the shape-retaining film F4 was used as the shape-retaining film, and in Example 5, the shape-retaining film F5 was used as the shape-retaining film. The size of the laminated body was a rectangular parallelepiped having a length of 50 mm and a width of 70 mm. In addition, what the sheet-like epoxy resin composition (thickness 40 micrometers) pinched | interposed between a base material (L) and a base material (H) respond | corresponds to the surface sealing material as used in this application.

  After measuring the thickness T1 of the obtained laminate, the laminate was heated at 80 ° C. for 3 hours to thermally cure the sheet-like epoxy resin composition. Thereafter, the laminate was cooled to 25 ° C., and the laminate was placed on a horizontal plate. The distance between the upper surface of the horizontal plate and the corners of the laminate was measured for each of the four corners to determine an average value T2. Next, the warpage amount T3 was calculated by subtracting T1 from T2.

  As shown in Table 2, although the linear expansion coefficient between the substrate (H) and the substrate (L) is large, the average warpage amount is suppressed to 2 mm or less by providing the shape retention layer. Recognize. And when it does not have a shape retention layer like the comparative example 1 shown by Table 3, or a shape retention layer is a thermosetting resin like the comparative example 2, an average curvature amount will be 4 mm or more. I understand that.

Since the amount of warpage of the organic EL device of the present invention is suppressed, the destruction of the organic EL element is reduced and further thinning is possible.

Claims (10)

An organic EL device including a base material (H), a surface sealing material, a base material (L), and a shape-retaining layer in this order, and an organic EL element is disposed on the base material (H) or the base material (L) Because
The linear expansion coefficient of the base material (L) is smaller than the linear expansion coefficient of the base material (H), and the linear expansion coefficient of the base material (H) and the linear expansion coefficient of the base material (L) And a difference of 5 × 10 ⁻⁶ cm / cm / ° C. or more,
The shape retention layer contains a thermoplastic polymer having a softening point of 110 ° C. or higher, and the difference between the linear expansion coefficient of the shape retention layer and the linear expansion coefficient of the substrate (H) is 160 × 10 ⁻⁶ cm / cm / An organic EL device having a temperature of ℃ or lower.   The organic EL device according to claim 1, wherein the surface sealing material is a cured product of a thermosetting resin composition, and a curing temperature of the thermosetting resin composition is 50 to 150 ° C.   The organic EL device according to claim 1, wherein the surface sealing material includes a cured product of one or more kinds of resins selected from the group consisting of epoxy resins and silicone resins.   The thermoplastic polymer is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyamide, polycarbonate, polypropylene (PP) and polybutylene terephthalate (PBT). The organic EL device according to any one of claims 1 to 3, wherein the organic EL device is one or more kinds of resins. The organic EL device according to claim 1, wherein the base material (H) has a linear expansion coefficient of 20 × 10 ^{−6 to} 180 × 10 ⁻⁶ cm / cm / ° C.   The substrate (H) contains one or more polymers selected from the group consisting of aluminum, ester (co) polymers, cyclic olefin (co) polymers, and 4-methyl-1-pentene (co) polymers. The organic EL device according to any one of claims 1 to 5. The linear expansion coefficient of the base material (L) is 1 × 10 ^{−6 to} 100 × 10 ⁻⁶ cm / cm / ° C. The organic EL device according to claim 1.   The organic EL device according to any one of claims 1 to 7, wherein the substrate (L) is glass, silicon, an ester (co) polymer, polyimide, polycarbonate, or polyamide. A base material (H), a thermosetting resin composition, a base material (L), and a shape retention layer are included in this order, and an organic EL element is disposed on the base material (H) or the base material (L). A first step of preparing a structure;
A second step of thermosetting the thermosetting resin composition;
A method for producing an organic EL device, comprising:
The linear expansion coefficient of the base material (L) is smaller than the linear expansion coefficient of the base material (H), and the linear expansion coefficient of the base material (H) and the linear expansion coefficient of the base material (L) difference between is not less ^{5 × 10 -6 cm / cm /} ℃ or higher, the shape-retaining layer comprises a thermoplastic polymer above the softening point of 110 ° C., and the shape-retaining layer linear expansion coefficient between the base material (H ) Of the linear expansion coefficient is 160 × 10 ⁻⁶ cm / cm / ° C. or less. An organic EL panel comprising the organic EL device according to claim 1.

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