KR101644708B1 - Pressure Sensitive Adhesive Sheet - Google Patents

Abstract

The present invention relates to a pressure-sensitive adhesive sheet and a method of manufacturing an organic electronic device using the same. When the adhesive sheet is used to encapsulate the organic electronic device, when the protective film used for protecting the barrier film is peeled off or when the release film on the adhesive layer above the adhesive layer for adhering the barrier film to the organic electronic device is peeled off, It is possible to prevent the defective process. The present invention also provides a pressure-sensitive adhesive sheet capable of effectively preventing damage to the organic electronic device during the process and a method of manufacturing the organic electronic device using the same.

Description

[0001] Pressure Sensitive Adhesive Sheet [0002]

The present invention relates to a pressure-sensitive adhesive sheet, a method of manufacturing an organic electronic device using the same, and an organic electronic device.

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, there has been proposed a method of applying a moisture barrier film to effectively block penetration of oxygen or moisture from the outside into an organic electronic device such as an OLED.

However, the conventional barrier film for encapsulating OLEDs is composed of a single layer between two release films, which has a problem that the adhesive peeling property is extremely low. Particularly, as the size of the barrier film increases due to the large-sized OLED, the defective defect rate of the barrier film during the sealing process of the OLED increases. For example, when the protective film or the release film protecting the barrier film is peeled off, peeling failure occurs in which the peeling of the adhesive film occurs.

In order to solve this problem, attempts have been made to use a release film having merely different peeling properties, but it has not been solved by itself. Therefore, there is a need to develop a pressure-sensitive adhesive sheet for sealing that can effectively reduce moisture penetration while reducing damage to organic electronic devices, and at the same time, improve process defects that may occur in an OLED sealing process.

The present invention is characterized in that when the organic electronic device is encapsulated using the adhesive sheet, the protective film used for protecting the barrier film is peeled off or the release film on the adhesive layer above the adhesive layer for attaching the barrier film to the organic electronic device, The present invention also provides a pressure-sensitive adhesive sheet capable of effectively preventing deterioration in peeling, such as lifting, and effectively preventing damage to the organic electronic device in the peeling step, and a method for manufacturing an organic electronic device using the same.

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. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. And the scope of the present invention is not limited by the thickness, size, ratio or the like shown in the drawings.

The present invention relates to a pressure-sensitive adhesive sheet. In one example, the adhesive sheet can be applied to encapsulate an organic electronic device. Further, the pressure-sensitive adhesive sheet may have a multi-layer structure.

Exemplary adhesive sheets for encapsulating organic electronic devices include protective films; A barrier film formed on the protective film; An adhesive layer formed on the barrier film; And a release film formed on the adhesive layer. In one example, the pressure-sensitive adhesive sheet may satisfy the following general formula (1).

[Formula 1]

A? B

In the general formula (1), A represents the peeling force (peel rate: 0.3 m / min, peel angle: 180 DEG) between the adhesive layer and the release film in the state that the width of the adhesive sheet is 1 inch. In the above, B represents the peel force (peel rate: 0.3 m / min, peel angle: 180 DEG) between the protective film and the barrier film in the state that the width of the adhesive sheet is 1 inch. In the present specification, the peeling force A and the peeling force B may be peeling forces measured under the same measurement conditions such as the same peeling speed and peeling angle for the same adhesive sheet sample (same width). In one example, the pressure-sensitive adhesive sheet of the present invention controls the peeling force B between the protective film and the barrier film to be equal to or greater than the peeling force A between the pressure-sensitive adhesive layer and the release film, It is possible to minimize the damage of the organic electronic device while improving the process defects in which part of the organic electronic device is detached.

Further, in the specific embodiment of the present invention, the pressure-sensitive adhesive sheet may satisfy the following general formula (2).

[Formula 2]

2 gf / inch B - A 20 gf / inch

The peeling force B (peel rate: 0.3 m / min, peel angle: 180 DEG) between the protective film and the barrier film as described in the above-mentioned general formula 2 is the peeling force A m / min, peeling angle: 180 deg.). In one example, the difference between the peeling force B between the protective film and the barrier film and the peeling force A between the adhesive layer and the release film is 2 to 19 gf / inch, 3 to 18 gf / inch, 5 to 17 gf / inch, 5 to 15 gf / inch, 7 to 12 gf / inch, or 8 to 10 gf / inch.

Further, in one example, the protective film may satisfy the following general formula (3).

[Formula 3]

13 gf / inch ≤ B ≤ 25 gf / inch

The peeling force B (peeling speed: 0.3 m / min, peeling angle: 180 deg.) Between the protective film and the barrier film may be 13 to 25 gf / inch as described in the general formula 3. [ In one example, the peel force B between the call film and the barrier film may be 14 to 24 gf / inch, 14 to 22 gf / inch, or 14 to 20 gf / inch.

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 pressure-sensitive adhesive sheet according to the present invention includes, for example, a protective film 1, a barrier film 2, an adhesive layer 3, and a release film 4 which are sequentially stacked from the bottom as shown in Fig. 1 .

The protective film (1) is formed for preventing scratching of the barrier film in the transfer step using the adsorption plate for fixing during the automation process. The release film (4) is formed on the adhesive layer It is a film that is peeled off to become. That is, when the adhesive sheet according to the embodiments of the present invention is ultimately applied to the encapsulation of the organic electronic device, the protective film 1 and the release film 4 are not included in the organic electronic device.

When the adhesive sheet is applied to the sealing process of the organic electronic device, the releasing film 4 and the protective film 1 are required to be peeled off. In this case, the releasing film 4 and the protective film 1 It is required to cleanly peel off without residue, and to reduce defects in which the barrier film 2 is lifted or partly separated.

Figs. 2 to 4 are cross-sectional views showing some processes for applying an adhesive sheet according to one example of the present invention to an organic electronic device encapsulating process. The steps shown in FIGS. 2 to 4 are sequentially performed. First, as shown in FIG. 2, the release film 4 is peeled from the adhesive sheet at room temperature to use the adhesive sheet of the present invention for encapsulation of organic electronic devices. Then, as the release film 4 is peeled off, the adhesive layer 3 contacting the outside is adhered to the base layer 5. Thereafter, the protective film 1 on the opposite side of the pressure sensitive adhesive sheet to which the substrate layer 5 is finally attached is peeled off at room temperature, and the pressure sensitive adhesive sheet is used in the sealing process of the organic electronic device.

As used herein, the term substrate layer 5 may be formed of glass or SiNx deposited glass, but is not limited thereto. Further, an organic electronic device may be formed on the base layer. In one example, the organic electronic device may be an organic light emitting diode.

In order to improve the peeling failure phenomenon in the pressure-sensitive adhesive sheet according to the embodiments of the present invention used in the peeling process, the peeling force A between the pressure-sensitive adhesive layer and the release film as shown in the general formula (1) (B) between the barrier film (1) and the barrier film (2). Thus, it is possible to prevent floating at the interface between the protective film (1) and the barrier film (2) during the step of peeling the release film (4).

As described above, the difference between the peeling force (B) between the protective film and the barrier film and the peeling force (A) between the adhesive layer and the release film can be 2 gf / inch to 20 gf / inch. In the case where the difference in peel force is less than 2 gf / inch, the barrier film may be lifted from the protective film on the adsorption plate, resulting in peeling failure. If the difference in peel strength exceeds 20 gf / inch, the releasing film 4 is removed and the adhesive layer 3 is adhered on the OLED base layer 5, The adhesive layer 3 may peel off from the base layer 5 or the interface between the barrier film 2 and the adhesive layer 3 may peel off. In this case, the organic electronic device formed on the base layer 5 may be damaged.

Further, in one example, the peel force B between the protective film and the barrier film may be 13 gf / inch to 25 gf / inch. After the releasing film 4 is removed and the adhesive layer 3 is adhered to the base layer 5 on which the organic electronic device is formed by controlling the peeling force as described above, 3 is peeled from the base layer 5 and the interface between the barrier film 2 and the adhesive layer 3 is peeled off.

In the embodiment of the present invention, the pressure-sensitive adhesive layer has a storage elastic modulus at a temperature of 25 캜, a strain of 5% at a frequency of 1 Hz of 0.1 MPa to 10 MPa, 0.2 MPa to 8 MPa, 0.21 MPa to 6 MPa, 0.22 MPa to 4 MPa, 0.23 MPa to 2 MPa, 0.24 MPa to 1 MPa or 0.25 MPa to 0.8 MPa. When the pressure-sensitive adhesive layer has a too low storage elastic modulus at room temperature, the pressure-sensitive adhesive layer leaks to the side, thereby contaminating the release film, thereby increasing the initial peeling force. The present application can more effectively protect the device by sealing the organic electronic device using the adhesive layer having the storage elastic modulus within the above range. On the other hand, in the present application, the adhesive layer satisfying the storage elastic modulus has a high tack property, so that there is a high probability that the peeling failure occurs in the step of removing the release film in the automation process. The peeling failure can be suppressed through the above- .

Further, in the embodiment of the present invention, the pressure-sensitive adhesive layer has a loss coefficient (tan?) Of 5% strain at a temperature of 25 占 폚 at a frequency of 1 Hz of 0.2 to 0.6, 0.21 to 0.55, 0.22 to 0.5, 0.23 to 0.45, 0.4 or 0.25 to 0.39.

In this case, the loss coefficient tan? Has a value of the loss elastic modulus G '' / storage elastic modulus G '(G' / G ') and may be 0.6 or less. That is, when the flowability of the pressure-sensitive adhesive layer is increased, the pressure-sensitive adhesive layer may leak. Therefore, the pressure-sensitive adhesive layer is preferably 0.6 or less. However, if the loss factor is lower than 0.2, the pressure-sensitive adhesive layer may become too hard, so that it can not be effectively adhered to the base layer, which makes it unsuitable for use in sealing organic electronic elements.

In this specification, the storage elastic modulus and the loss elastic modulus were measured by using an ARES (Advanced Rheometric Expansion System) for a circular sample (diameter: 8 mm, thickness: 600 탆) 50 gf, and then changing the frequency from 0.1 Hz to 100 Hz under 5% strain conditions. In the above, the storage elastic modulus and the loss elastic modulus at a frequency of 1 Hz were measured.

The term " Advanced Rheometric Expansion System (ARES) " as used herein is a rheometer for evaluating viscoelastic properties such as viscosity, shear modulus, loss modulus and storage modulus of a material. The device is a mechanical measuring device that applies a dynamic and steady state to a specimen and can measure the transmission torque, which is the degree to which the specimen is resistant to the applied stress.

In one example, the adhesive layer may comprise a viscous resin. The tacky resin may be a thermoplastic elastomer tacky resin. As the elastomer, for example, an ester type thermoplastic elastomer, an olefin type elastomer, a silicone type elastomer, an acrylic type elastomer, or a mixture thereof can be used. As the olefinic thermoplastic elastomer, a polybutadiene resin, an elastomer or a polyisobutylene resin or an elastomer may be used. On the other hand, in the present application, the pressure-sensitive adhesive layer comprising the thermoplastic elastomer resin is suitable for sealing an organic electronic device in terms of moisture barrier properties or optical characteristics, but has a high tack property. Therefore, there is a high probability that the separation defect occurs in the process of removing the release film in the automation process. In this application, the separation failure can be suppressed through the above-described separation force relationship.

The polyisobutylene resin or elastomer may include a high molecular weight polyisobutylene resin. For example, the viscous resin may be a copolymer of an olefinic compound containing a diene and one carbon-carbon double bond. Here, the olefin compound may include isobutylene, propylene, ethylene or the like, and the diene may be a monomer capable of polymerizing with the olefin-based compound, and examples thereof include 1-butene, 2-butene, isoprene, . ≪ / RTI > That is, the adhesive resin of the present application includes, for example, a homopolymer of an isobutylene monomer; A copolymer obtained by copolymerizing an isobutylene monomer with another monomer capable of polymerization; Or a mixture thereof. In one example, the copolymer of an olefinic compound and a diene containing one carbon-carbon double bond may be a butyl rubber. By using a specific resin as described above, the water barrier property required according to the field to which the adhesive layer is applied in the present application can be satisfied.

The adhesive resin may be a base resin having a weight average molecular weight (Mw) to the extent that it can be formed into a film. In one example, the range of the weight average molecular weight to such an extent that molding into a film shape can range from about 30,000 to 2,000,000, 100,000 to 1,500,000, or 100,000 to 100,000. The term "weight average molecular weight" as used herein means a value converted to a standard polystyrene measured by GPC (Gel Permeation Chromatograph).

The adhesive layer may further comprise a tackifier. As the tackifier, for example, a hydrogenated petroleum resin obtained by hydrogenating a petroleum resin can be used. The hydrogenated petroleum resin may be partially or fully hydrogenated and may be a mixture of such resins. Such a tackifier may be selected to have good compatibility with the tackifier resin and excellent water barrier properties. Specific examples of the hydrogenated petroleum resins include hydrogenated terpene resins, hydrogenated ester resins, and hydrogenated dicyclopentadiene resins. The weight average molecular weight of the tackifier may be from about 200 to about 5,000. The content of the tackifier can be appropriately adjusted for the control of peel strength and viscoelasticity as described above. For example, the tackifier may be added in an amount of 5 parts by weight to 65 parts by weight, 10 parts by weight to 60 parts by weight, 15 parts by weight to 55 parts by weight, 15 parts by weight to 50 parts by weight, or 15 parts by weight To 45 parts by weight of the pressure-sensitive adhesive layer.

In the present application, the unit "parts by weight" means the weight ratio. By adjusting the weight ratio as described above, it is possible to effectively maintain physical properties such as initial adhesion, durability and peel strength of the adhesive layer.

Further, the adhesive layer may comprise a polyfunctional acrylate. The polyfunctional acrylate may be at least one selected from the group consisting of trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (Meth) acrylate, trimethylolpropane tri (meth) acrylate, trifunctional urethane (meth) acrylate, tris (meth) acryloxyethylisocyanurate, diglycerin tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (metha) acrylate, dipentaerythritol penta (Meth) acrylate, tricyclodecane dimethanol diacrylate, dicyclopentadiene di (meth) acrylate, ethylene glycol di And urethane (meth) may be at least one selected from the group consisting of acrylate. The multifunctional acrylate may be included in an amount of 5 to 40 parts by weight, 8 to 30 parts by weight, 10 to 25 parts by weight, 10 to 20 parts by weight or 10 to 18 parts by weight based on 100 parts by weight of the adhesive resin have. By including the polyfunctional acrylate in the above range, a crosslinking structure in an appropriate range can be formed, and the above peel force relationship and the viscoelastic characteristics of the adhesive layer can be satisfied.

Further, the tacky resin may include a copolymerizable monomer having at least one crosslinkable functional group. The copolymerizable monomer having a crosslinkable functional group may be at least one selected from the group consisting of a hydroxyl group-containing comonomer, a carboxyl group-containing comonomer and a nitrogen-containing comonomer. By including the copolymerizable monomer having a crosslinkable functional group as a polymerized unit of the adhesive resin, the wettability of the adhesive layer to the base layer can be increased and the adhesion to the base layer can be improved.

In an embodiment of the present invention, the pressure-sensitive adhesive layer may further comprise a multifunctional crosslinking agent which crosslinks the pressure-sensitive adhesive resin. The polyfunctional crosslinking agent may be an isocyanate compound, an epoxy compound, an aziridine compound or a metal chelate compound. In consideration of the kind of the crosslinkable functional group contained in the resin, one or two or more crosslinking agents You can choose. Examples of the isocyanate compound include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate, and naphthalene diisocyanate, An addition reaction product of an isocyanate compound and a polyol, and the like. As the polyol, trimethylolpropane or the like may be used. Examples of the epoxy compound include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylol propane triglycidyl ether, N, N, N ', N'-tetraglycidylethylenediamine or glycerin diglycidyl ether And aziridine compounds such as N, N'-toluene-2,4-bis (1-aziridine carboxamide), N, N'-diphenylmethane- 1-aziridinylphosphine oxide or the like such as bis (1-aziridine carboxamide), triethylene melamine, bisisopropanoyl-1- (2-methyl aziridine) Can be used. As the metal chelate compound, there can be used a compound in which the polyvalent metal exists in a state of being poured into acetylacetone, ethyl acetate or the like. As the polyvalent metal, there can be used aluminum, iron, zinc, tin, , Magnesium or vanadium, and the like.

The multifunctional crosslinking agent is used in an amount of 0.01 to 10 parts by weight, 0.1 to 9.5 parts by weight, 0.5 to 9 parts by weight, 1 part by weight to 8.5 parts by weight, 1.5 parts by weight to 8 parts by weight, 2 parts by weight To 8 parts by weight or from 2.5 parts by weight to 8 parts by weight in the adhesive layer. The crosslinking degree can be controlled by including the polyfunctional crosslinking agent in a specific range, and the adhesion can be lowered in relation to the releasing film by increasing the degree of crosslinking.

In one embodiment of the present application, the multifunctional acrylate of the adhesive layer may form a Semi-Interpenetrating Polymer Network (hereinafter, Semi-IPN) together with the adhesive resin.

As used herein, the term " Semi-IPN " includes at least one polymer network and at least one linear or branched polymer, wherein at least a portion of the linear or branched polymer is permeable to the polymeric crosslinked structure Structure. The Semi-IPN can be distinguished from the IPN structure in that the linear or branched polymer can theoretically be separated from the polymeric crosslinked structure without loss of chemical bonding.

In one embodiment, the crosslinked structure may be a crosslinked structure formed by application of heat, a crosslinked structure formed by irradiation of an active energy ray, or a crosslinked structure formed by aging at room temperature. The term " active energy ray " as used herein includes alpha-particle beams, proton beams, as well as microwaves, infrared (IR), ultraviolet A particle beam such as a neutron beam or an electron beam, and the like, and may be typically an ultraviolet ray or an electron beam. By introducing the above-mentioned Semi-IPN structure, it is possible to increase the mechanical properties such as the processing performance of the adhesive layer, control the elastic modulus through crosslinking, and achieve high moisture barrier performance and excellent panel lifetime. In addition, through the crosslinked structure, adhesion with the substrate layer on which the organic electronic device is formed can be improved while satisfying an appropriate modulus of elasticity and facilitating peeling in relation to the release film, and effectively used for encapsulating organic electronic devices .

The adhesive layer may further include a radical initiator that can induce polymerization of the polyfunctional acrylate. The radical initiator may be a photoinitiator or an initiator. The specific kind of the photoinitiator can be appropriately selected in consideration of the curing rate and the possibility of yellowing. For example, benzoin, hydroxy ketone, amino ketone or phosphine oxide photoinitiators can be used. Specific examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether , Benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethyl anino acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy- Methyl-1 - [4- (methylthio) phenyl] -2-morpholino-propane-1-one, 1-hydroxycyclohexyl phenyl ketone, (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethyl anthraquinone, 2-t-butyl anthraquinone, 2-aminoanthraquinone, thioxanthone, 2-ethylthioxanthone, 2- - dimethylthio Diethyl thioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamino benzoic acid ester, oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] Propanone] and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide can be used.

The radical initiator may be included in an amount of 0.01 to 20 parts by weight or 0.05 to 10 parts by weight based on 100 parts by weight of the polyfunctional acrylate. This can effectively induce the reaction of the polyfunctional acrylate and prevent the deterioration of the properties of the pressure-sensitive adhesive layer due to the remaining components after curing.

In an embodiment of the present invention, the adhesive layer may have a gel content of 50% to 70% represented by the following general formula (4).

[Formula 4]

Gel content (%) = Y / X x 100

In the general formula (4), X is the mass of the adhesive layer, Y is the mass of the adhesive layer, which is immersed in toluene for 3 hours at 60 ° C, filtered through a 200 mesh screen, Min. ≪ / RTI > Specifically, the gel content may preferably be 55% to 70% or 60% to 70%. By adjusting the degree of crosslinking of the adhesive layer as described above, it is possible to simultaneously satisfy the peeling force for the release film of the adhesive layer and the adhesive force to the base layer. For example, when the gel content is less than 50%, peeling of the adhesive layer may occur, and when the gel content is more than 70%, the adhesive force to the base layer may be reduced and the organic electronic element encapsulation can not be effectively performed.

The specific type of the release film that can be used in the present invention is not particularly limited. As the release film in the present invention, for example, a general polymer film in this field can be used. In the present invention, for example, the release film layer may be a polyethylene terephthalate film, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polyvinyl chloride film, An ethylene-vinyl 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, appropriate mold release treatment may be performed on one side or both sides of the release film of the present invention. Examples of the releasing agent used in the releasing treatment of the releasing film include an alkyd type, a silicone type, a fluorine type, an unsaturated ester type, a polyolefin type, a wax type and the like. Among them, an alkyd type, a silicone type or a fluorine type releasing agent is preferably used from the viewpoint of heat resistance But is not limited thereto.

In the present invention, the thickness of the release film as described above is not particularly limited, and can be appropriately selected according to the application to which it is applied. For example, in the present invention, the thickness of the film may be about 10 탆 to 500 탆, or about 20 탆 to 200 탆. If the thickness is less than 10 탆, deformation of the base layer film may easily occur during the manufacturing process, and if it exceeds 500 탆, the economical efficiency is lowered.

The thickness of the pressure-sensitive adhesive layer of the present invention is not particularly limited and may be suitably selected in consideration of the application to which it is applied.

The present invention also relates to a method of manufacturing an organic electronic device.

The present invention provides a method for producing a pressure sensitive adhesive sheet, comprising: peeling a release film from the above-mentioned pressure sensitive adhesive sheet; Laminating the adhesive layer to a substrate layer in which the organic electronic device is formed so as to contact the organic electronic device; And a step of peeling the protective film.

In the above step, in the step of peeling the release film, the peeling force A between the adhesive layer and the release film and the peeling force B between the protective film and the barrier film may satisfy the following general formula 2 as described above.

[Formula 2]

2 gf / inch B - A 20 gf / inch

Further, in the above step of peeling the protective film, the peeling force B between the protective film and the barrier film may satisfy the following general formula 3 as described above.

[Formula 3]

13 gf / inch ≤ B ≤ 25 gf / inch

The present invention also relates to organic electronic devices. The organic electronic device comprising: a substrate; An organic electronic device formed on a substrate; And an adhesive layer formed to seal the front surface of the organic electronic device and having a storage elastic modulus of 0.1 MPa to 10 MPa at a temperature of 25 ° C and a strain of 5% at a frequency of 1 Hz. The organic electronic device may further include a cover substrate formed on the adhesive layer.

In one example, the adhesive layer has a loss factor (tan?) Of 0.2 to 0.6, 0.21 to 0.55, 0.22 to 0.5, 0.23 to 0.45, 0.24 to 0.4 or less at a temperature of 25 deg. 0.25 to 0.39. The method of measuring the storage elastic modulus and the loss coefficient is as described above.

The organic electronic device may be, for example, an organic light emitting device. In one example, the organic electronic device may be a top emission organic light emitting device.

The adhesive layer can be formed as a structural encapsulating layer that efficiently fixes and supports the substrate and the cover substrate while exhibiting excellent moisture barrier properties and optical characteristics in an organic electronic device.

In addition, the sealing layer encapsulates the front surface of the organic electronic device, so that the region where the light is emitted can exhibit excellent transparency, whereby the shape of the organic electronic device such as top emission or bottom emission A stable encapsulation structure can be realized irrespective of the size.

The term sealing layer in this specification may mean an adhesive layer covering both the top and side surfaces of the organic electronic device.

When the organic electronic device is encapsulated using the adhesive sheet according to the embodiments of the present invention, the release film on the adhesive layer on the adhesive layer for peeling off the protective film used for protecting the barrier film or for adhering the barrier film to the organic electronic device It is possible to prevent the defective process such as lifting of the barrier film during peeling, thereby preventing the defective process and preventing the organic electronic device from being damaged during the process.

1 is a cross-sectional view showing an adhesive sheet according to one example of the present invention.
Figs. 2 to 4 are cross-sectional views showing some processes for applying an adhesive sheet according to one example of the present invention to an organic electronic device encapsulating process.

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.

75 parts by weight of B80 / B10 (BASF) blended in a ratio of 2: 1 as a PIB resin, 25 parts by weight of SU90 (Kolon Chemical) as a tackifying resin, and TMPTA 0.1 parts by weight of Ir651 (Ciba) as a photoinitiator relative to 100 parts by weight of a polyfunctional acrylate was added to the mixture, followed by high-speed mixing for 1 hour to prepare an adhesive layer solution.

The adhesive layer solution prepared above was applied to the releasing surface of the releasing PET using a comma coater, dried in a dryer at 130 캜 for 5 minutes, and irradiated with UV to produce a pressure-sensitive adhesive layer having a thickness of 40 탆.

A barrier film (I-component OBF0501) and a barrier film protective film (Nitto Denko Co., RP301) were laminated on the adhesive layer to produce a multi-layered adhesive sheet.

Example  2.

A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1, except that the PIP resin and the tackifying resin Su90 content ratio were adjusted to 7: 3.

Example  3.

A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1, except that 20 parts by weight of TMPTA (MI Corporation) was used as the polyfunctional acrylate, based on 100 parts by weight of the resin.

Comparative Example  One.

A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1, except that the multifunctional acrylate and the photoinitiator were not added.

Comparative Example  2.

A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1, except that the PIP resin and the tackifying resin, Su90, were adjusted to a ratio of 6: 4.

Experimental Example

One. Peel force  A and B

The protective film was fixed at a constant temperature and humidity condition under the condition that the width of the measurement sample of the pressure-sensitive adhesive sheet prepared in Examples and Comparative Examples was 1 inch, and then the releasing film was pressed at a speed of 0.3 m / min using a TA (texture analyzer) , And the peel force A was measured by peeling at an angle of 180 degrees (ASTM 3330).

After removing the release film, the adhesive layer was adhered to the substrate layer, and then the protective film was peeled off at a rate of 0.3 m / min and a 180 degree angle using a TA instrument to measure the peeling force B (ASTM 3330 strain) .

2. Come  %

The pressure-sensitive adhesive layer prepared in Examples and Comparative Examples was sampled at a predetermined portion and weighed, and then placed in toluene and stored in an oven at 60 ° C for 3 hours. After that, it is filtered through a wire mesh (200 mesh) and dried in an oven at 130 ° C for 1 hour to remove toluene contained in the sample filtered through the wire mesh. Calculate the weight of the existing adhesive layer and the weight of the portion not dissolved in toluene.

[Formula 4]

Gel content (%) = Y / X x 100

In the general formula (4), X is the mass of the adhesive layer, Y is the mass of the adhesive layer, which is immersed in toluene for 3 hours at 60 ° C, filtered through a 200 mesh screen, Min. ≪ / RTI >

3. Measurement of storage modulus and loss factor

The pressure-sensitive adhesive layers prepared according to Examples and Comparative Examples were prepared as a circular sample (diameter: 8 mm, thickness: 600 μm). The circular sample was set to have an axial force of 50 gf (vertical force) at a temperature of 25 캜 by using a parallel plate of ARES (Advanced Rheometric Expansion System, TA ARES-G2) The storage elastic modulus and the loss elastic modulus at 1 Hz were measured while varying the frequency from 0.1 Hz to 100 Hz under the strain of 100%.

The loss factor, tan δ, was calculated from the loss elastic modulus G '' / storage elastic modulus G '(G''/G').

3. Missing phenomenon  And peeling failure

The exfoliation of the pressure-sensitive adhesive means a phenomenon in which the pressure-sensitive adhesive is escaped in the cross-sectional direction due to the viscoelastic property of the pressure-sensitive adhesive, so that there is no adhesion between the films or the release film is not removed. The pressure-sensitive adhesive sheets prepared according to Examples and Comparative Examples were observed at a magnification of 60 at a magnification of 60 by a handy type microscope. X was shown when there was no exfoliation, and 0 when exfoliation was observed.

The pressure sensitive adhesive sheet prepared according to Examples and Comparative Examples was placed on a vacuum plate, and the release film was removed. When the releasing film is peeled off, (1) between the protective film and the barrier film, or (2) when the releasing film is not peeled off, the peeling failure is indicated. When the protective film is removed after attaching the adhesive layer to the base layer GLASS after removing the release film, the interface between the base layer and the adhesive layer is peeled off or the interface between the barrier film and the adhesive layer is peeled off Peeling failure. [Delta] in the case where the peeling failure occurred in one of the cases of X, the peeling failure, and the peeling failure of 2 or more occurred.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Peel force B 15 15 15 15 15 Peel strength A 6 6.5 2 23 14 Gel% 66 65 75 0 40 Modulus (Mpa) 0.3 0.29 0.4 0.15 0.19 tan δ 0.25 0.3 0.2 0.65 0.62 Missing phenomenon X X X O O Poor peeling X X △ O O

As described above, the dropout phenomenon can mean the phenomenon that the adhesive layer flows along the cut surface. Therefore, in the case of a pressure-sensitive adhesive sheet having a multilayer structure, each layer may adhere to each other due to separation of the adhesive layer, and the film may not peel off even if the release-peeling value is low in the release-

In Comparative Example 1, the peeling force A is higher than the peeling force B, so that the peeling force between the protective film and the barrier film increases, and the adhesive layer and the release film are not peeled off. In the case of Comparative Example 2, since the storage elastic modulus is low and the tan delta value is high, soft properties are obtained, so that the adhesive layer dropout phenomenon occurs. When the release film is peeled from the adhesive layer, The adhesive layer and the release film are not peeled off.

1: Protective film
2: barrier film
3: Adhesive layer
4: release film
5: Base layer

Claims (17)

Protective film; A barrier film formed on the protective film; An adhesive layer formed on the barrier film and having a storage elastic modulus of 0.1 MPa to 10 MPa at a temperature of 25 DEG C and a strain of 5% at a frequency of 1 Hz; And a release film formed on the adhesive layer,
An adhesive sheet for encapsulating organic electronic devices satisfying the following general formula (1):
[Formula 1]
A? B
In the general formula (1), A represents the peeling force (peel rate: 0.3 m / min, peeling angle: 180 DEG) between the adhesive layer and the release film in the state that the width of the adhesive sheet is 1 inch, (Peel rate: 0.3 m / min, peel angle: 180 DEG) between the protective film and the barrier film in the state that the width of the adhesive sheet is 1 inch. The pressure-sensitive adhesive sheet according to claim 1, which satisfies the following general formula (2):
[Formula 2]
2 gf / inch B - A 20 gf / inch The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer has a loss coefficient (tan?) Of 0.2 to 0.6 at a temperature of 25 占 폚 and a strain of 5% at a frequency of 1 Hz. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer comprises a thermoplastic elastomer adhesive resin. The pressure-sensitive adhesive sheet according to claim 4, wherein the viscous resin is a polyisobutylene resin. 5. The pressure-sensitive adhesive sheet according to claim 4, wherein the pressure-sensitive adhesive layer further comprises a tackifier. The pressure-sensitive adhesive sheet according to claim 6, wherein the tackifier is a hydrogenated terpene resin, a hydrogenated ester resin, a hydrogenated dicyclopentadiene resin, or a mixture thereof. The pressure-sensitive adhesive sheet according to claim 6, wherein the tackifier is contained in an amount of 5 to 65 parts by weight based on 100 parts by weight of the tackifier resin. 5. The pressure-sensitive adhesive sheet according to claim 4, wherein the pressure-sensitive adhesive layer further comprises a polyfunctional acrylate. 10. The thermosetting resin composition according to claim 9, wherein the polyfunctional acrylate is selected from the group consisting of trimethylol propane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) (Meth) acrylate, trimethylolpropane tri (meth) acrylate, trifunctional urethane (meth) acrylate, tris (meth) acryloxyethylisocyanurate, diglycerin tetra Acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol tetra (metha) acrylate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, tricyclodecane dimethanol diacrylate, dicyclopentadiene di (meth) acrylate, ethylene glycol di ) Acrylate and urethane (meth) acrylate. The pressure-sensitive adhesive sheet according to claim 9, wherein the multifunctional acrylate is contained in an amount of 5 to 40 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin. The adhesive sheet of claim 9, wherein the multifunctional acrylate forms a semi-interpenetrating polymer network (Semi-IPN) with the tackifier resin. The pressure-sensitive adhesive sheet according to claim 9, wherein the pressure-sensitive adhesive layer further comprises a radical initiator. The pressure-sensitive adhesive sheet according to claim 13, wherein the radical initiator is contained in an amount of 0.01 to 20 parts by weight based on 100 parts by weight of the polyfunctional acrylate. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer has a gel content of 50% to 70% according to the following general formula (4):
[Formula 4]
Gel content (%) = Y / X x 100
In the general formula (4), X is the mass of the adhesive layer, Y is the mass of the adhesive layer, which is immersed in toluene for 3 hours at 60 ° C, filtered through a 200 mesh screen, Min. Peeling the release film from the adhesive sheet of claim 1;
Laminating the adhesive layer to a substrate layer in which the organic electronic device is formed so as to contact the organic electronic device; And
And peeling off the protective film. delete

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