KR101373945B1 - Fast Curable Epoxy Adhesive Composition at Low Temperature and Encapsulation Method of Organic Electronic Device Using the Same - Google Patents

Abstract

Embodiments of the present invention relate to a low-temperature fast curing type epoxy adhesive composition, an adhesive film, an organic electronic device encapsulation product, and a method for encapsulating an organic electronic device, more specifically comprising an epoxy resin and a latent curing agent, 70 It is a low-temperature fast curing type epoxy adhesive composition that is used for encapsulation or encapsulation of organic electronic devices with a degree of curing of 90% or more at a temperature of 3 ° C. or more. A defect that may occur during encapsulation of organic electronic devices by providing low temperature fast curing properties. It provides a method of encapsulating an organic electronic device minimized.

Description

Fast Curable Epoxy Adhesive Composition at Low Temperature and Encapsulation Method of Organic Electronic Device Using the Same}

Embodiments of the present invention are directed to a method for encapsulating a low temperature fast curing type epoxy adhesive composition and an organic electronic device using the same.

An organic electronic device (OED) refers to an apparatus that includes an organic material layer that generates holes and electrons to generate an alternating current. Examples thereof include a photovoltaic device, a rectifier, A transmitter and an organic light emitting diode (OLED).

Organic light emitting diodes (OLEDs) among the organic electronic devices have lower power consumption, faster response speed, and are advantageous for thinning display devices or illumination. In addition, OLEDs are expected to be applied in various fields covering various portable devices, monitors, notebooks, and televisions because of their excellent space utilization.

In commercialization of OLEDs and expansion of applications, the main problem is durability. Organic materials and metal electrodes contained in OLEDs are very easily oxidized by external factors such as moisture. Thus, products containing OLEDs are highly sensitive to environmental factors. Accordingly, various methods have been proposed to effectively block penetration of oxygen or moisture from the outside into organic electronic devices such as OLEDs.

In addition to increasing the size and thickness of organic electronic devices, encapsulation materials that can effectively block the penetration of moisture and reduce damage to organic electronic devices can be provided while encapsulating organic electronic devices in a simpler process to provide structural advantages. Required.

Embodiments of the present invention provide a low temperature fast curing type epoxy adhesive composition, an adhesive film, an organic electronic device encapsulation product using the same, and a method of encapsulating an organic electronic device.

One embodiment of the present invention includes an epoxy resin and a latent curing agent having a water vapor transmission rate of 20 g / m ² · day or less in a cured state, and a curing degree of 90% or more within 3 hours at a temperature of 70 ° C. It provides a low temperature fast curing epoxy adhesive composition used for encapsulation or encapsulation of an organic electronic device (OED).

Another embodiment of the present invention provides an adhesive film encapsulating an organic electronic device, the adhesive film having an adhesive layer comprising the low temperature rapid curing epoxy adhesive composition.

In addition, another embodiment of the present invention is a substrate; An organic electronic device formed on the substrate; And an adhesive film comprising a cured product of the low temperature fast curing type epoxy adhesive composition encapsulating the organic electronic device so as to cover the entire surface of the organic electronic device.

In addition, the present invention comprises the steps of applying the adhesive film on the substrate on which the organic electronic device is formed, the adhesive layer of the adhesive film to cover the entire surface of the organic electronic device; And it provides a method of encapsulating an organic electronic device comprising the step of curing the adhesive layer.

Embodiments of the present invention are fast curing at 70 ℃, a relatively low temperature compared to the epoxy resin and a fast curing agent, but a latent curing agent at a slow temperature at room temperature, including the latent curing agent when applied to the encapsulation of the organic electronic device It is possible to minimize curling defects that may occur in the organic electronic device by reducing the thermal expansion due to the difference in the coefficient of thermal expansion and the shrinkage of the adhesive film generated during curing of the film. In addition, by encapsulating the organic electronic device in a film-type adhesive film at room temperature, it is possible to improve the life and durability of the organic electronic device compared to the liquid adhesive. In addition, the adhesive film provides a structural advantage of supporting and fixing the upper and lower substrates of the organic electronic device, thereby simplifying the organic electronic device sealing method and reducing the cost.

1 and 2 are cross-sectional views showing an adhesive film according to one example of the present invention.
3 is a cross-sectional view showing an encapsulation product of an organic electronic device according to one example of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known general functions or configurations will be omitted. In addition, the accompanying drawings are schematic for the purpose of better understanding of the present invention, and in order to more clearly describe the present invention, parts irrelevant to the description are omitted. It is shown, and the scope of the present invention is not limited by the thickness, size, ratio and the like shown in the drawings.

The epoxy adhesive composition according to one embodiment of the present invention is used for encapsulation or encapsulation of an organic electronic device, and includes an epoxy resin and a latent curing agent, and has low temperature fast curing properties. Specifically, rapid curing is performed at 70 ° C. to 90 ° C., which is relatively low temperature, compared to the epoxy resin and the conventional curing agent. However, at room temperature, a latent curing agent having a slow reaction rate is used. Unlike the epoxy adhesive composition, a degree of curing of 90% can be achieved within 3 hours at a relatively low temperature of 70 ° C.

The inventors of the present invention have recognized that there is a problem in that curling is poor according to the conventional encapsulation method of the organic electronic device when the organic electronic device uses the plastic substrate, unlike when the organic electronic device uses the glass substrate. Curing phenomena that can occur when the organic electronic device is encapsulated are irregular plastic curls, which causes poor manufacturing process of the organic electronic device. For example, curling is impossible to automatically transfer the organic electronic device, or computers and cameras. Using the to locate the organic electronic device, to recognize the numerical value of the automatic visual recognition for the preparation of the next process, or causes a problem when attaching the driving chip. The adhesive film for encapsulation of a conventional organic electronic device needs to be cured at a temperature of 100 ° C. or higher, and the above problems are caused by the difference in thermal expansion coefficient between layers and thermal stress caused by shrinkage of the adhesive film due to curing. Will occur.

Accordingly, embodiments of the present invention provide an epoxy adhesive composition that can be hardened at a low temperature in order to solve the problems of such a conventional adhesive film to overcome the thermal stress due to the shrinkage of the adhesive film due to the difference in the coefficient of thermal expansion between the curing and the curing. This minimizes curling defects that can occur in organic electronic devices using plastic substrates.

As used herein, the term " organic electronic device " refers to an article or apparatus having a structure including an organic material layer that generates alternating electric charges using holes and electrons between a pair of electrodes facing each other, But are not limited to, photovoltaic devices, rectifiers, transmitters, and organic light emitting diodes (OLEDs). In one example of the present invention, the organic electronic device may be an OLED.

The epoxy adhesive composition may be a curable hot melt adhesive composition. The curable hot-melt adhesive composition maintains a solid or semi-solid state at room temperature, and when applied with heat, fluidity can be adhered to the flat plate without bubbles. It means the adhesive composition of the form that can be fixed. Compositions according to embodiments of the present invention may have a viscosity at room temperature of 10 ⁶ dyne sec / cm ² or more, or 10 ⁷ dyne sec / cm ^{2 or} more. The term "room temperature" means a natural temperature that is not warmed or reduced, for example, about 15 ° C to 35 ° C, more specifically about 20 ° C to 25 ° C, and more specifically about 25 ° C. Can mean. The viscosity can be measured using an Advanced Rheological Expansion System (ARES). By adjusting the viscosity of the adhesive composition in the above range, in the process of encapsulation of the organic electronic device, it is possible to encapsulate the flat plate with smooth process uniformity and uniform thickness. Further, problems such as shrinkage and volatile gas which may be generated by hardening of the resin and the like can be greatly reduced, and physical or chemical damage to the organic electronic device can be prevented. As long as the adhesive maintains a solid or semi-solid state at room temperature, the upper limit of the viscosity is not particularly limited, and is controlled in the range of about 10 ⁹ dynesec / cm ² or less, for example, in consideration of processability and the like. can do.

The low temperature fast curing type epoxy adhesive composition has low temperature fast curing properties and stability at room temperature. The low temperature fast curing property refers to a property that cures rapidly even at a low heating temperature. The low temperature is 70 ° C to 90 ° C, and the temperature is lower than 100 ° C to 200 ° C, which is a temperature at which a general thermosetting adhesive is cured. It is to enable curing without causing problems due to deterioration in the curing step, such as a plastic substrate. Epoxy adhesive composition according to embodiments of the present invention is preferably not only having the low temperature fast curing properties as described above, but also stability at room temperature. That is, it is preferable to use a latent curing agent in the epoxy adhesive composition according to the embodiments of the present invention, since it should be maintained at a stable state because the reactivity is low at room temperature, and may further use a room temperature curing retardant. Room temperature stability in embodiments of the present invention means that the viscosity increase rate after 3 days at room temperature is within 10%, or 5%, the lower limit is not particularly limited, but may be 0% or more.

The epoxy resin that can be used in the embodiments of the present invention is not particularly limited as long as it can provide the above physical properties. For example, an epoxy resin having two or more epoxy reactors may be used. The epoxy resin having two or more epoxy reactors is a compound having two or more epoxy groups in a molecule, and in one embodiment of the present invention, which contains two or more epoxy reactors, an epoxy equivalent of 180 g / eq to 300 g / eq Epoxy resins can be used. By using an epoxy resin having an epoxy equivalent in the above range, properties such as low temperature fast curing and room temperature stability can be effectively maintained. Examples of such epoxy resins include bisphenol epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, and bisphenol S type epoxy resins; Trifunctional epoxy resin, tetrafunctional epoxy resin, and cresol novolak epoxy resin, a bisphenol A novolak epoxy resin, a kind of novolak epoxy resin such as phenol novolak epoxy resin, or a mixture of two or more kinds thereof may be mentioned.

As the epoxy resin, a thermosetting or photocurable resin may be used. The term " thermosetting resin " means a resin that can be cured through an appropriate heat application or aging process, and the term " photo-curing resin " means a resin that can be cured by irradiation with electromagnetic waves. The category of electromagnetic waves includes microwaves, infrared rays (IR), ultraviolet rays (UV), X-rays and γ-rays, as well as α-particle beams, proton beams, A particle beam such as a neutron beam and an electron beam, and the like. One example of the photocurable resin is a cationic photocurable resin. The cationic photocurable resin means a resin that can be cured by cationic polymerization or cation curing reaction induced by irradiation of electromagnetic waves. In addition, the epoxy resin may be a dual curable resin that includes both thermosetting and photocuring properties.

In addition, in the embodiments of the present invention, the epoxy resin, aromatic or aliphatic; Or a linear or branched epoxy resin may be used. For example, an epoxy resin containing a cyclic structure in a molecular structure can be used, and specifically, an epoxy resin containing an aromatic group (for example, a phenyl group) can be used. When the epoxy resin contains an aromatic group, the cured product has excellent thermal and chemical stability and exhibits a low moisture absorption amount, thereby improving the reliability of the organic electronic device encapsulation structure. Specific examples of the aromatic group-containing epoxy resin that can be used in the embodiments of the present invention include a biphenyl type epoxy resin, a dicyclopentadiene type epoxy resin, a naphthalene type epoxy resin, a dicyclopentadiene modified phenol type epoxy resin, and a cresol It may be one kind or a mixture of two or more of the epoxy resin, bisphenol epoxy resin, xylox epoxy resin, polyfunctional epoxy resin, phenol novolac epoxy resin, triphenol methane-type epoxy resin and alkyl-modified triphenol methane epoxy resin, It is not limited to this.

As the epoxy resin in the embodiments of the present invention, a silane-modified epoxy resin, for example, a silane-modified epoxy resin having an aromatic group may be used. When an epoxy resin having such a silane-modified structure and having a silane group is used, it is possible to maximize the adhesiveness with the glass substrate or the substrate inorganic material of the organic electronic device, and to improve the moisture barrier property, the durability and the reliability. The specific kind of the above epoxy resin is not particularly limited, and such a resin can be easily obtained from a place of purchase such as Kukdo Chemical.

The epoxy resin exhibits adhesion and moisture barrier properties by crosslinking between resins when cured with a matrix resin. The epoxy resin may have a water vapor transmission rate (WVTR) in a cured state of 20 g / m ² · day or less, or 10 g / m ² · day or less, and the lower limit thereof is not particularly limited, but 1 g / It may be m ² · day or more. The term "cured state" refers to a curable resin, when the epoxy resin is cured or crosslinked alone or through reaction with other components such as a curing agent or the like, and is used as an encapsulant to hold components such as moisture adsorbents and fillers, It means the state converted to the state which can exhibit the performance as a structural adhesive. In this invention, the said water vapor transmission rate is the water vapor transmission rate measured with respect to the thickness direction of the said hardened | cured material under 38 degreeC and 100% of relative humidity, after hardening an epoxy resin and making the hardened | cured material into the film form of thickness 80micrometer. The water vapor transmission rate is measured according to ASTM F1249.

By controlling the moisture permeability within the above range, it is possible to effectively suppress the penetration of moisture, moisture or oxygen into the organic electronic device encapsulation product.

In the present invention, the moisture permeability in the cured state of the resin is such that the lower the numerical value, the better the sealing structure is. The lower limit is not particularly limited.

The low temperature fast curing type epoxy adhesive composition of the present invention includes a curing agent capable of reacting with the epoxy resin to form a matrix such as a crosslinked structure, and such a curing agent may use a latent curing agent capable of performing a curing reaction at a low temperature. .

In the embodiments of the present invention, as the latent curing agent, an addition reactant such as an adduct of imidazole and epoxy may be used alone, or an imidazole curing agent having a solubility in a liquid imidazole curing agent or a solvent at room temperature. It can be used in combination with a curing retardant.

The latent curing agent may proceed with the curing reaction by reacting with the epoxy resin, the curing time at 70 ℃ 3 hours or less, room temperature stability of 3 days or more, to provide both low temperature fast curing properties and room temperature stability characteristics Can be.

The addition reactant of the imidazole and the epoxy is a latent curing agent, a compound obtained by high molecular weight by reacting an imidazole compound and an epoxy resin, and generally exhibits a low solubility at room temperature in an epoxy resin. In the case of such a latent hardener, when the amount of moisture in the composition increases, preservation stability decreases, so attention to handling of the epoxy resin composition is required. In addition to the epoxy resin, the addition reaction product may be used by adding acrylonitrile, ethylene oxide, or the like to an imidazole or amine compound.

According to another embodiment of the present invention, when using a general thermosetting curing agent, by using a room temperature curing retardant in combination, it is possible to provide an epoxy resin composition having both low temperature rapid curing and room temperature stability at the same time. Examples of such a thermosetting curing agent may be one kind or two or more kinds of various amine compounds, imidazole compounds, phenol compounds, phosphorus compounds, or acid anhydride compounds, but are not limited thereto.

As the room temperature curing retardant, for example, at least one selected from the group consisting of boric acid, phenylboric acid, salicylic acid, hydrochloric acid, sulfuric acid, oxamic acid, tetraphthalic acid, isophthalic acid, phosphoric acid, acetic acid, and lactic acid Can be used.

The latent curing agent may be included in 5 to 30 parts by weight based on 100 parts by weight of the epoxy resin, by controlling the content of the latent curing agent in the above range can adjust the curing rate and control the Tg of the cured resin.

When the room temperature curing retardant is used in combination, the room temperature curing retardant may be included in an amount of 5 to 20 parts by weight based on 100 parts by weight of the epoxy resin, and storage stability and curing rate may be controlled by using the above range.

In the present specification, unless otherwise specified, the unit " weight part " means a weight ratio between the respective components.

The adhesive composition of the present invention may further include a moisture adsorbent in addition to the epoxy resin and the latent curing agent. The term " moisture adsorbent " can be used to collectively refer to components capable of adsorbing or removing moisture or moisture introduced from the outside through moisture and chemical reaction, and is also referred to as a moisture-reactive adsorbent.

The moisture reactive adsorbent chemically reacts with moisture, moisture, or oxygen introduced into the adhesive layer to adsorb moisture or moisture. The specific kind of moisture adsorbent that can be used in the embodiments of the present invention is not particularly limited. For example, in the case of the water reactive adsorbent, metal powder such as alumina, metal oxide, organometal oxide, metal salt or phosphorus pentoxide (P ₂ O ₅₎ may be mentioned one kind or as mixtures of two or more thereof, such as, there may be mentioned the case of the physical adsorbent, silica, zeolite, titania, zirconia, montmorillonite or the like.

Specific examples of the metal oxide include lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), barium oxide (BaO), calcium oxide (CaO) and magnesium oxide (MgO) Examples include lithium sulfate (Li ₂ SO _4), sodium sulfate (Na ₂ SO _4), calcium sulfate (CaSO _4), magnesium sulfate (MgSO _4), cobalt sulfate (CoSO _4), sulfate, gallium (Ga ₂ (SO _{4) 3),} titanium sulfate (Ti (SO _{4) 2)} or nickel sulfate (a sulfate such as NiSO _4), calcium chloride (CaCl _2), magnesium chloride (MgCl _2), strontium chloride (SrCl _2), chloride, yttrium (YCl ₃₎ , Cobalt chloride (CuCl ₂ ), cesium fluoride (CsF), tantalum fluoride (TaF ₅ ), niobium fluoride (NbF ₅ ), lithium bromide (LiBr), calcium bromide (CaBr ₂ ), cesium bromide (CeBr ₃ ) (SeBr _4), vanadium bromide (VBr _3), a metal halide such as magnesium bromide (MgBr _2), barium iodide (BaI _2), or magnesium iodide (MgI _2); Or metal chlorates such as barium perchlorate (Ba (ClO ₄ ) ₂ ) or magnesium perchlorate (Mg (ClO ₄ ) ₂ ), and the like.

In embodiments of the present invention, the moisture adsorbent, such as the metal oxide, etc., may be blended into the composition in a suitably processed state. For example, the thickness of the adhesive layer may be a thin film of 30 μm or less according to the type of organic electronic device to which the adhesive composition is to be applied, and in this case, a grinding process of the moisture absorbent may be required. For pulverizing the moisture adsorbent, a process such as a three-roll mill, a bead mill or a ball mill may be used. In addition, when the adhesive composition of the present invention is used for organic light emitting devices of the top emission type, the permeability of the adhesive layer itself becomes very important, and thus the size of the moisture adsorbent needs to be small. Therefore, the grinding process may be required even in such applications.

The adhesive composition may include a moisture adsorbent in an amount of 5 parts by weight to 50 parts by weight, or 10 parts by weight to 25 parts by weight with respect to 100 parts by weight of the epoxy resin. By controlling the content of the moisture adsorbent within the above range, it is possible to maximize the moisture barrier property within a range that does not damage the organic electronic device.

Adhesive composition according to embodiments of the present invention may include a filler, for example an inorganic filler. The filler can suppress the penetration by lengthening the movement path of moisture or moisture that penetrates into the encapsulation structure, and maximize the barrier to moisture and moisture through interaction with the matrix structure of the epoxy resin and the moisture adsorbent. have. Specific examples of the filler that can be used in the embodiments of the present invention are not particularly limited and include clay, talc, silica, barium sulfate, aluminum hydroxide, calcium carbonate, magnesium carbonate, zeolite, zirconia, titania or montmorillonite Or a mixture of two or more of them may be used.

In addition, in order to increase the coupling efficiency of the filler and the epoxy resin, a product surface-treated with an organic material may be used as the filler, or a coupling agent may be additionally added.

The adhesive composition may include a filler in an amount of 1 part by weight to 100 parts by weight, 1 part by weight to 50 parts by weight, or 5 parts by weight to 30 parts by weight, based on 100 parts by weight of the epoxy resin. By controlling the filler content to 1 part by weight or more, it is possible to provide a cured product having excellent moisture or moisture barrier properties and mechanical properties, and to prevent sedimentation of the moisture adsorbent. In addition, by controlling the filler content to 100 parts by weight or less, it is possible to manufacture in the form of a film, it is possible to provide a cured product exhibiting adhesive properties even when formed into a thin film.

The adhesive composition may further include an initiator capable of initiating a curing reaction of the epoxy resin, for example, a cationic photopolymerization initiator. The kind of the initiator, for example, the cationic photopolymerization initiator, which can be used in the embodiments of the present invention is not particularly limited, and for example, aromatic diazonium salts, aromatic iodine aluminum salts, aromatic sulfonium salts or iron-arene complexes Known cationic polymerization initiators such as and the like can be used, among which an aromatic sulfonium salt can be used, but is not limited thereto.

In this case, the content of the initiator may be, for example, 0.01 part by weight to 10 parts by weight, or 0.1 part by weight to 3 parts by weight based on 100 parts by weight of the epoxy resin. If the content of the cationic photopolymerization initiator is too small, there is a fear that sufficient curing will not proceed. If the content is too large, the content of the ionic substance after curing will increase to lower the durability of the adhesive, ) Is formed, which is disadvantageous from the viewpoint of optical durability, and corrosion may occur depending on the base material. Therefore, an appropriate content range can be selected in consideration of this point.

The epoxy adhesive composition may further include a high molecular weight resin. The high molecular weight resin may serve to improve moldability, such as when molding the composition into a film or sheet shape. In addition, it may serve as a high temperature viscosity regulator to control the flowability during the hot-melting process.

The type of high molecular weight resin that can be used in the embodiments of the present invention is not particularly limited as long as it has compatibility with other components such as the epoxy resin. Specific examples of the high molecular weight resin that can be used include resins having a weight average molecular weight of 20,000 or more such as phenoxy resin, acrylate resin, high molecular weight epoxy resin, ultra high molecular weight epoxy resin, high polarity functional group- A high polarity functional group-containing reactive rubber, and the like, but is not limited thereto.

When the high molecular weight resin is included in the composition of the present invention, the content is not particularly limited to be adjusted according to the desired physical properties. For example, in the present invention, the high molecular weight resin may be included in an amount of about 200 parts by weight or less, 150 parts by weight or less, or about 10 to 100 parts by weight or less based on 100 parts by weight of the epoxy resin. By controlling the content of the high molecular weight resin to 200 parts by weight or less, it can effectively maintain the compatibility with each component of the resin composition, it can also serve as an adhesive.

The composition according to the embodiments of the present invention may also contain additional fillers for improving the durability of the cured product, mechanical strength, coupling agents for improving adhesion, plasticizers, UV stabilizers and antioxidants, without affecting the effects of the present invention. The same additive may additionally be included.

Other embodiments of the present invention also relate to an adhesive film encapsulating an organic electronic device having an adhesive layer comprising the above-mentioned low temperature fast curing epoxy adhesive composition.

The structure of the adhesive film according to the embodiments of the present invention is not particularly limited as long as it includes the above adhesive layer. For example, a substrate film or a release film (hereinafter also referred to as " first film "; And a structure including the adhesive layer formed on the base film or the release film. The adhesive film may further include a base film or release film (hereinafter sometimes referred to as " second film ") formed on the adhesive layer.

1 and 2 are cross-sectional views of adhesive films according to one example of the present invention. As shown in FIG. 1, the adhesive film according to embodiments of the present invention may include an adhesive layer 22 formed on a base film or a release film 21.

In another aspect of the present invention, as shown in FIG. 2, the adhesive film may further include a base film or a release film 23 formed on the adhesive layer 22. For example, a gas barrier layer for a flexible display implementation may be placed on one side of the substrate film. However, the adhesive film shown in the drawings is only an aspect of the present invention. The adhesive film according to the embodiments of the present invention may have a form including a composition of the present invention without a supporting substrate and an adhesive layer that maintains a solid or semi-solid state at room temperature, In some cases, it may be formed in the form of a double-sided adhesive film.

The specific kind of the first film that can be used in the embodiments of the present invention is not particularly limited. As the first film, for example, a general polymer film in this field can be used. Examples of the substrate or release film include a polyethylene terephthalate film, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polyvinyl chloride film, a polyurethane film, Acetate film, an ethylene-propylene copolymer film, an ethylene-ethyl acrylate copolymer film, an ethylene-methyl acrylate copolymer film, or a polyimide film. In addition, a suitable mold release treatment may be performed on one or both sides of the base film or release film of the present invention. Examples of the releasing agent used in the releasing treatment of the base film include an alkyd type, a silicone type, a fluorine type, an unsaturated ester type, a polyolefin type or a wax type. Among them, an alkyd type, a silicone type or a fluorine type releasing agent can be used from the viewpoint of heat resistance , But is not limited thereto.

Also, the kind of the second film (hereinafter sometimes referred to as " cover film ") that can be used in the embodiments of the present invention is not particularly limited either. For example, as the second film, within the scope exemplified in the first film described above, the same or different kinds of the first film may be used. In addition, the second film may also be subjected to appropriate mold release treatment.

The thickness of the base film or the release film is not particularly limited and may be appropriately selected depending on the application to which it is applied. For example, the thickness of the first film may be about 10 탆 to 500 탆, or about 20 탆 to 200 탆. If the thickness is less than 10 mu m, the base film may be easily deformed during the manufacturing process. If the thickness exceeds 500 mu m, the economical efficiency is lowered.

The thickness of the second film is also not particularly limited. For example, the thickness of the second film may be set to be the same as that of the first film. Further, the thickness of the second film may be set to be relatively thin in comparison with the first film in consideration of the processability and the like.

The thickness of the adhesive layer included in the adhesive film according to embodiments of the present invention is not particularly limited and can be appropriately selected in accordance with the following conditions in consideration of the application to which the film is applied. The adhesive layer may be, for example, about 5 탆 to 200 탆, or about 5 탆 to 100 탆. The thickness of the adhesive layer can be adjusted in consideration of embedding properties, fairness and economical efficiency when used as an encapsulant of an organic electronic device.

In the embodiments of the present invention, the method for producing such an adhesive film is not particularly limited. For example, a first step of coating a coating solution containing a composition of an adhesive layer on a base film or a release film; And a second step of drying the coating liquid coated in the first step. In the method for producing an adhesive film as described above, a third step of additionally pressing the base film or the release film on the coating liquid dried in the second step may be further performed.

The first step is to prepare a coating solution by dissolving or dispersing the above-described composition in a suitable solvent. In this process, the content of the epoxy resin and the like contained in the coating liquid may be appropriately controlled according to the desired moisture barrier properties and film formability.

The kind of the solvent used for preparing the coating liquid is not particularly limited. However, when the drying time of the solvent is excessively long or when drying at a high temperature is required, a problem may arise in terms of workability or durability of the adhesive film, so that a solvent having a volatilization temperature of 100 ° C or lower can be used. In view of film formability and the like, a small amount of a solvent having a volatilization temperature higher than the above range may be mixed and used. Examples of such solvents include methyl ethyl ketone (MEK), acetone, toluene, dimethylformamide (DMF), methyl cellosolve (MCS), tetrahydrofuran (THF) or N-methylpyrrolidone (NMP) Or a mixture of two or more kinds thereof, but is not limited thereto.

The method of applying the coating liquid as described above to the base film or the release film in the first step is not particularly limited, and examples thereof include a knife coat, a roll coat, a spray coat, a gravure coat, a curtain coat, a comma coat or a lip coat A known method can be used without limitation.

The second step is to dry the coating solution coated in the first step, to form an adhesive layer. That is, in the second step, the coating liquid applied to the film is heated to dry and remove the solvent, whereby an adhesive layer can be formed. The drying conditions are not particularly limited. For example, the drying may be performed at a temperature of 70 to 150 캜 for 1 to 10 minutes.

In the method of manufacturing the adhesive film, a third step of pressing the additional base film or the release film on the adhesive layer formed on the film may be further performed after the second step. Such a third step may be carried out by coating the film and then pressing the additional release film or the base film (cover film or second film) on the dried adhesive layer by a hot roll laminate or a pressing process. At this time, the third step may be performed by hot roll lamination in terms of the possibility and efficiency of the continuous process, wherein the process is performed at a temperature of about 10 캜 to 100 캜 at a pressure of about 0.1 kgf / cm ² to 10 kgf / cm < ² >.

3 is a cross-sectional view illustrating an encapsulation product of an organic electronic device according to an exemplary embodiment of the present disclosure. Another embodiment of the present invention includes a substrate 31; An organic electronic device (33) formed on the substrate (31); And an adhesive film 32 including a cured product of the above-described composition for encapsulating the organic electronic device 33 to cover the entire surface of the organic electronic device 33. Here, covering the front surface of the organic electronic device 33 means that the adhesive film 32 is attached to the entire surface of the organic electronic device 33 without any gap (all surfaces not in contact with the substrate such as the top, side, etc.) .

The organic electronic device encapsulation product may further include a second substrate (cover substrate) 34 on the adhesive film 32, wherein the adhesive film 32 is bonded to the second substrate 34 And serves to adhere the substrate 31. Adhesive composition according to embodiments of the present invention, has an excellent moisture barrier properties, excellent optical properties, and serves as a structural adhesive for fixing and supporting the substrate and the cover substrate to provide an adhesive film acting as an encapsulation layer can do.

The organic electronic device 33 may be, for example, an organic light emitting diode.

The organic electronic device encapsulation product may further include a protective film (not shown) for protecting the organic electronic device 33 between the adhesive film 32 and the organic electronic device 33.

The organic electronic device encapsulation product according to the present invention has the advantage of simplifying the manufacturing process and reducing the process cost, and can be used regardless of the design method of the organic electronic device, and can provide excellent mechanical durability to the organic electronic device. There is an advantage to that.

In another embodiment of the present invention, there is provided a method of manufacturing an organic electronic device, comprising the steps of: applying an adhesive layer of the above-mentioned adhesive film to a substrate on which an organic electronic device is formed to cover the front surface of the organic electronic device; And a step of curing the adhesive layer.

The step of applying the adhesive film to the organic electronic device may be performed by a hot roll laminate, a hot press, or a vacuum press method of an adhesive film, and is not particularly limited.

The applying of the adhesive film to the organic electronic device may be performed at a temperature of 50 ° C. to 70 ° C., and the curing step may be performed by heating to a temperature range of 70 ° C. to 90 ° C. or by irradiating UV. have.

It is also possible to add a step of attaching the adhesive film so as to be in contact with glass or metal which is an additional sealing material.

The sealing method of the organic electronic device includes forming a transparent electrode on a substrate such as a glass or a polymer film by vacuum deposition or sputtering, and forming an organic material layer on the transparent electrode. The organic material layer may include a hole injecting layer, a hole transporting layer, a light emitting layer, an electron injecting layer, and / or an electron transporting layer. Then, a second electrode is further formed on the organic material layer. The adhesive film described above is then applied to cover all of the organic electronic devices on top of the organic electronic device on the substrate. The method of applying the adhesive film is not particularly limited and may be applied to an organic electronic device formed on a substrate, for example, a cover substrate (e.g., a glass or a polymer Film) can be applied by heating, pressing or the like. In this step, for example, when the adhesive film is transferred onto the cover substrate, the substrate or the release film formed on the film is peeled off by using the above-mentioned adhesive film, and then heat is applied to the vacuum press or vacuum laminate Or the like can be transferred onto the cover substrate. In this process, when the curing reaction of the adhesive film is made in a certain range or more, the adhesive force or the adhesive force of the adhesive film may decrease, so that the process temperature may be controlled to about 70 ° C. to 90 ° C., and the process time may be controlled within 5 minutes. Similarly, a vacuum press or a vacuum laminator can be used when the cover substrate onto which the adhesive film is transferred is heated and pressed onto the organic electronic device. The temperature condition at this stage can be set as described above, and the process time can be within 10 minutes.

Further, an additional curing process may be performed on the adhesive film to which the organic electronic device is pressed. This curing process (final curing) may be performed, for example, in a heating chamber or a UV chamber. The conditions for the final curing can be appropriately selected in consideration of the stability of the organic electronic device and the like.

However, the above-described manufacturing process is merely an example for encapsulating the organic electronic device, and the process order, process conditions, and the like can be freely modified. For example, the order of the transfer and the pressing process may be changed by first transferring the adhesive film to the organic electronic device on the substrate and then pressing the cover substrate. Alternatively, after a protective layer is formed on the organic electronic device, an adhesive film may be applied and the cover substrate may be omitted and cured.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples, but the scope of the present invention is not limited by the following examples.

Example  One

50 g of CaO (Aldrich) as a water adsorbent was added to methyl ethyl ketone at a concentration of 30 wt% to prepare a water adsorbent solution, and the solution was milled for 24 hours by a ball mill process. Separately, 200 g of bisphenol epoxy resin (RE-310, Nippon Kayaku) and 150 g of phenoxy resin (YP-50, Hwado Chemical) were added to the reactor at room temperature, and diluted with methyl ethyl ketone. Thereafter, the inside of the reactor was replaced with nitrogen, and the prepared solution was homogenized. A water adsorbent solution prepared in advance was added to the homogenized solution, and 40 g of imidazole-epoxy adduct (PN-40, Ajinomoto) as a curing agent was added thereto, followed by rapid stirring for 1 hour.

The stirred solution was filtered through a filter having a hole size of 20 μm. Subsequently, the filtered solution was applied on a release PET having a thickness of 50 μm using a comma coater and dried at 110 ° C. for 1 minute in a dryer to prepare an adhesive film having an adhesive layer having a thickness of 20 μm. Thereafter, the prepared adhesive film was laminated on a cover release film of the same material as the release film using a laminator to obtain an adhesive film for sealing an organic electronic device.

Example  2

Instead of 200 g of bisphenol epoxy resin (RE-310, Nippon Kayaku) used in Example 1, 100 g of silane-modified epoxy resin (KSR177, Kukdo Chemical) and 100 g of tetrafunctional bisphenol epoxy resin (HP-4710, DIC) were used. Example 1 except that 40 g of imidazole-epoxy adduct (P0505, Shikoku Chemical) and 20 g of epoxy-phenol boric ester (L-07N) were used instead of 40 g of rho imidazole-epoxy adduct (PN-40, Ajinomoto) In the same manner as in the above, an adhesive film for sealing an organic electronic device was obtained.

Example  3

Instead of 200 g of bisphenol epoxy resin (RE-310, Nippon Kayaku) used in Example 1, 150 g of silane-modified epoxy resin (KSR177, Kukdo Chemical) and 50 g of cycloaliphatic epoxy resin (Celloxide 2021P, Daicel Chemical) were used. An organic electronic device was encapsulated in the same manner as in Example 1 except that 10 g of triarylsulfonium hexafluoro phosphate salt (Aldrich), a UV cationic photoinitiator, was used instead of 40 g of imidazole-epoxy adduct (PN-40, Ajinomoto). The adhesive film for was obtained.

Comparative Example  One

Except for using 200 g of the acrylic modified resin (KR-628, Kukdo Chemical) instead of 200 g of the bisphenol epoxy resin (RE-310, Nippon Kayaku) used in Example 1 was carried out in the same manner as in Example 1 for encapsulating organic electronic devices An adhesive film was obtained.

Comparative Example  2

Example 1 except that 40g of 2-ethyl-4-methylimidazole (2E4MZ, Shikoku Chemical) was used as a curing agent instead of 40g of the imidazole-epoxy adduct (PN-40, Ajinomoto) used in Example 1 above. In the same manner, an adhesive film for sealing an organic electronic device was obtained.

Experimental Example

1. Calcium test

Calcium (Ca) was deposited on the glass substrate in the size of 8 mm x 8 mm x 100 nm (width x length x thickness). Subsequently, the cover glass on which the adhesive layers prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were transferred was laminated on calcium on the glass substrate so that the bezel was 3 mm, and a vacuum press was applied. Using, heat pressing at 70 ° C. for 2 minutes, curing at 70 ° C. for 3 hours to form an encapsulation layer, and prepared specimens. In the case of Example 3, after heating and pressing for 2 minutes at 70 ℃, UV of 5mW / cm ² intensity was irradiated for about 5 minutes, and cured after 1 hour at 70 ℃. While maintaining the specimen in a constant temperature and humidity chamber at 80 ° C. and 90% relative humidity, the time at which the end of the calcium deposited portion was oxidized and changed transparently was measured.

The measurement results as described above are summarized in Table 1 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Invisibility start time (h) <205 <250 <220 <40 <155

2. Moisture permeability , Hardness and room temperature stability test

After curing the epoxy resin (except adsorbent) used in Examples 1-3 and Comparative Examples 1-2, the cured product was made into a film shape having a thickness of 80 μm, the thickness of the cured product under 38 ° C. and 100% relative humidity. The moisture vapor permeability was measured according to ASTM F1249 with respect to the direction. In addition, the exothermic peak due to the curing reaction was confirmed by DSC analysis, and a sample cured for 3 hours at 70 ° C. was prepared to confirm the degree of curing, and the exothermic peak of the uncured powder was confirmed. In addition, after confirming the stability of the room temperature using a viscoelasticity measuring instrument at room temperature for 3 days after comparing the degree of change in viscosity as shown in Table 2 the results.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Water vapor permeability (g / m ² · day) 18 10 13 240 27 Hardness (%) 91 93 - 66 72 Room temperature stability (%) 8 6 One 35 42

As can be seen above, the adhesive films of Examples 1 to 3 according to the embodiments of the present invention control moisture permeability of the resin to 20 g / m ² · day or less, thereby resisting moisture resistance of the encapsulation product of the organic electronic device. Curing of the organic electronic device by controlling so that the curing degree is 90% or more within 3 hours at a temperature of 70 ° C. or lower, and the room temperature stability is 3 days or more with a viscosity increase rate of 10% or less after 3 days of standing at room temperature. The defect can be minimized to ensure fairness. However, when the moisture permeability, the curing degree under the process conditions, or the room temperature stability is poor as in the comparative example, it can be confirmed that the effective encapsulation of the organic electronic device is not achieved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be appreciated that other embodiments are possible. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

21, 23: base film or release film
22: Adhesive layer
31: substrate
32: Adhesive film
33: organic electronic device
34: second substrate (cover substrate)

Claims (23)

An encapsulation of an organic electronic device containing an epoxy resin having a moisture permeability of 20 g / m ² · day or less in a cured state and a latent curing agent, having a degree of curing of 90% or more within 3 hours at a temperature of 70 ° C. or less, and having a room temperature stability of 3 days or more. Or low temperature rapid curing epoxy adhesive compositions used for encapsulation. According to claim 1, wherein the room temperature stability is the viscosity increase after 3 days at room temperature is 10% or less Low temperature fast curing epoxy adhesive composition. The low temperature rapid curing epoxy adhesive composition according to claim 1, wherein the epoxy resin comprises a liquid epoxy resin having an equivalent weight of 300 or less including two or more functional groups. The low temperature of claim 1, wherein the latent curing agent is a liquid imidazole compound or a combination of an imidazole compound having a solubility in a solvent and a room temperature curing retardant, or an addition reactant of epoxy and imidazole alone, or a combination of a curing retardant. Fast curing epoxy adhesive composition. The low temperature rapid curing epoxy adhesive composition according to claim 4, wherein the latent curing agent has a curing time of 70 hours or less and 3 hours or less, and a room temperature stability of 3 days or more. The low temperature fast curing type epoxy adhesive composition according to claim 1, wherein the latent curing agent is included in an amount of 5 to 30 parts by weight based on 100 parts by weight of the epoxy resin. The low temperature fast curing type epoxy adhesive composition according to claim 4, wherein the curing retardant is included in an amount of 5 to 20 parts by weight based on 100 parts by weight of the epoxy resin. The low temperature rapid curing epoxy adhesive composition of claim 1, wherein the epoxy adhesive composition further comprises a moisture reactive adsorbent. The low temperature rapid curing epoxy adhesive composition according to claim 8, wherein the moisture reactive adsorbent is alumina, metal oxide, organometal oxide, metal salt or phosphorus pentoxide. The method of claim 8, wherein the water reactive adsorbent is P ₂ O ₅ , Li ₂ O, Na ₂ O, BaO, CaO, MgO, Li ₂ SO ₄ , Na ₂ SO ₄ , CaSO ₄ , MgSO ₄ , CoSO ₄ , Ga _{2 (SO 4) 3, Ti} (SO 4) 2, NiSO 4, CaCl 2, MgCl 2, SrCl 2, YCl 3, CuCl 2, CsF, TaF 5, NbF 5, LiBr, CaBr 2, CeBr 3, SeBr 4 At least one selected from the group consisting of VBr ₃ , MgBr ₂ , BaI ₂ , MgI ₂ , Ba (ClO ₄ ) ₂ and Mg (ClO ₄ ) ₂ . The low temperature fast curing type epoxy adhesive composition according to claim 8, wherein the moisture adsorbent is included in an amount of 5 parts by weight to 50 parts by weight with respect to 100 parts by weight of the epoxy resin. The low temperature rapid curing epoxy adhesive composition of claim 1, wherein the epoxy adhesive composition further comprises a filler. The low temperature rapid curing epoxy adhesive composition according to claim 12, wherein the filler is at least one selected from the group consisting of clay, talc, silica, barium sulfate, aluminum hydroxide, calcium carbonate, magnesium carbonate, zeolite, zirconia, titania or montmorillonite. The low temperature fast curing type epoxy adhesive composition according to claim 12, wherein the filler is included in an amount of 1 to 50 parts by weight based on 100 parts by weight of the epoxy resin. The low temperature rapid curing epoxy adhesive composition of claim 1, wherein the epoxy adhesive composition further comprises an initiator. The low temperature rapid curing epoxy adhesive composition of claim 1, wherein the epoxy adhesive composition further comprises a high molecular weight resin. An adhesive film for encapsulating an organic electronic device having an adhesive layer comprising the low temperature fast curing epoxy adhesive composition according to any one of claims 1 to 16. Board; An organic electronic device formed on the substrate; And an adhesive film comprising a cured product of the composition according to any one of claims 1 to 16, wherein the organic electronic device is encapsulated to cover the entire surface of the organic electronic device. The organic electronic device encapsulation product of claim 18, further comprising a second substrate on the adhesive film, wherein the adhesive film adheres the second substrate to the substrate. Applying the adhesive film according to claim 17 to a substrate having an organic electronic device formed thereon such that the adhesive layer of the adhesive film covers the entire surface of the organic electronic device; And curing the adhesive layer. The method of claim 20, wherein applying the adhesive film to the organic electronic device is performed by hot roll lamination, hot pressing, or vacuum pressing of the adhesive film. The method of claim 20, wherein applying the adhesive film to the organic electronic device is performed at a temperature of 50 ° C. to 90 ° C. 21. The method of claim 21, wherein the curing step is performed by heating to 50 ° C. to 70 ° C. or irradiating UV.

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