KR20230076086A - Adhesive film for organic electronic device encapsulation with excellent panel adhesion at room temperature and long-term reliability, organic electronic device encapsulation material including the adhesive film and organic electronic device encapsulation method using the same - Google Patents

Abstract

Disclosed are an adhesive film for encapsulating an organic electronic device having excellent panel adhesion at room temperature and long-term reliability, an adhesive composition used therein, an encapsulant including the adhesive film, an encapsulation method using the same, and an organic electronic device encapsulated with the encapsulant do. The adhesive film for encapsulating an organic electronic device includes a buffer adhesive layer located on the side of the organic electronic device, and the buffer adhesive layer is tan (delta) obtained by dividing the loss modulus by the storage modulus of the buffer adhesive layer. The 25°C value is greater than or equal to 1.2 and less than 1.8.

Description

Adhesive film for organic electronic device encapsulation with excellent panel adhesion at room temperature and long-term reliability, encapsulant containing the adhesive film, and organic electronic device encapsulation method using the same {Adhesive film for organic electronic device encapsulation with excellent panel adhesion at room temperature and long-term reliability, organic electronic device encapsulation material including the adhesive film and organic electronic device encapsulation method using the same}

The present specification provides an adhesive film for encapsulating an organic electronic device having excellent panel adhesion at room temperature and long-term reliability, an adhesive composition used therein, an encapsulant including the adhesive film, an encapsulation method using the same, and an organic electronic device encapsulated with the encapsulant. It's about the device.

Specifically, in order to secure excellent room temperature panel adhesion and long-term reliability, by optimizing the rheological properties of composite materials, various physical properties such as adhesion, shear stress, resin flow, CTE (coefficient of thermal expansion), adhesion, and retention at room temperature are improved. An adhesive film for encapsulation of an organic electronic device capable of improving the manufacturing yield of an OLED panel, reducing manufacturing cost, and securing long-term reliability of a stable product, an adhesive composition used therein, an encapsulant containing the adhesive film, and encapsulation using the same It relates to a method and an organic electronic device sealed with the encapsulant.

Compared to conventional displays such as LCD, OLED, which is currently commercialized, has the advantage of having a simple structure due to self-luminescence and reducing the number of panel component parts by half, as well as various advantages such as colors close to natural colors, high contrast ratio, and reduced power consumption. Market needs are shifting to OLED.

However, OLED has a fatal problem of being vulnerable to moisture and gas, and various encapsulation technologies have been developed to overcome this problem.

Thin Film Encapsulation (TFE) is performed on small and medium-sized OLEDs such as smartphones. Thin film encapsulation (TFE) is a multi-layer structure in which an inorganic layer and an organic layer on a thin film formed by inkjet overlap each other, and the inorganic layer mainly prevents the inflow of oxygen or moisture to protect the OLED material. As a method of forming an inorganic layer for thin film encapsulation (TFE), there is a method using plasma CVD (PECVD) or ALD (Atomic Layer Deposition). It is being used.

On the other hand, a thin metal barrier layer for thin film encapsulation and an OLED panel are attached to a large display such as a TV, but an encapsulation adhesive film for OLED and an encapsulant containing the same are used to remove moisture and gas generated in the OLED panel. Currently being adopted, encapsulants and encapsulation technologies that prevent material deterioration due to moisture or oxygen have an important role in greatly influencing the lifespan or light emitting characteristics of OLED panels.

Although organic electronic device encapsulant technology has been developed, according to the research of the present inventors, in the case of the conventional organic electronic device encapsulant, the problem of deterioration of adhesion with the OLED panel at room temperature still occurred, resulting in non-adhesive areas. problems such as deterioration in long-term reliability, decrease in OLED panel manufacturing yield due to defects such as resin flow after bonding OLED panels, and deterioration in product reliability due to deterioration in adhesion during long-term storage of sealed products. It was found that several problems persisted.

In exemplary embodiments of the present invention, on one side, when manufacturing an organic electronic device such as an OLED panel, the adhesion between the organic electronic device and the adhesive layer of the adhesive film for encapsulation is excellent, resulting in the occurrence of adhesion bubbles, non-bonding areas, Adhesive film for encapsulation of organic electronic devices, which does not cause problems such as lifting, and has excellent manufacturing yield, adhesive composition used therein, organic electronic device encapsulant including the adhesive film, encapsulation method using the same, and encapsulation with the encapsulant It is intended to provide an organic electronic device.

In exemplary embodiments of the present invention, in another aspect, an adhesive film for encapsulating an organic electronic device having better long-term reliability by adjusting the properties of shear stress, CTE, resin flow, basic adhesion, and retention, and an adhesive used therein It is intended to provide a composition, an organic electronic device encapsulant including the corresponding adhesive film, an encapsulation method using the same, and an organic electronic device encapsulated with the encapsulant.

In exemplary embodiments of the present invention, an adhesive film for encapsulating an organic electronic device includes a buffer adhesive layer positioned on the organic electronic device side, and in order to secure adhesion to a panel at room temperature, the buffer adhesive layer has a storage modulus of the buffer adhesive layer. Provides an organic electronic device encapsulant film having excellent room temperature panel adhesion at 25 ° C. of Tan (delta) divided by Loss Modulus by (Storage Modulus) 1.2 or more and less than 1.8.

In an exemplary embodiment, the temperature (Tg) when Tan (delta) obtained by dividing the loss modulus by the storage modulus of the buffer adhesive layer is the maximum value is preferably 20 ° C to 27 ° C.

In an exemplary embodiment, the 25° C. viscosity of the buffer adhesive layer is preferably 11 to 300,000 Pa·S.

In an exemplary embodiment, it is preferable that the 25° C. viscosity of the entire adhesive layer including the moisture absorption adhesive layer positioned on the side of the buffer layer and the barrier layer such as the metal substrate is 150,000 to 550,000 Pa·S.

In an exemplary embodiment, in order to ensure stable long-term reliability, it is preferable that the value of the coefficient of thermal expansion (CTE) is 1000 ppm or less.

In an exemplary embodiment, in order to secure stable long-term reliability, the shear stress value measured at room temperature at a speed of 300 mm/min is preferably 3 kgf/φ6 mm or more.

In an exemplary embodiment, in order to ensure stable long-term reliability, a basic adhesive force value measured at a speed of 300 mm/min at room temperature is preferably 6 kgf/inch (about 25 mm) or more.

In an exemplary embodiment, in order to ensure stable long-term reliability, the adhesive strength after a thermal shock test in which 100 cycles of maintaining the temperature at -20 ° C for 30 minutes and then raising the temperature and maintaining the temperature at 60 ° C for 30 minutes is 66.7% or higher of the basic adhesive strength or 4 kgf /inch or more is preferred.

In an exemplary embodiment, in order to secure stable long-term reliability, it is preferable that the adhesive strength after a low temperature storage test in which it is left at -20 ° C for 1,000 hours is 66.7% or more of the basic adhesive strength or 4 kgf / inch or more.

In an exemplary embodiment, in order to secure stable long-term reliability, it is preferable that the adhesive strength after a high temperature storage test in which it is left at 60 ° C. for 1,000 hours is 66.7% or more of the basic adhesive strength or 4 kgf / inch or more.

In an exemplary embodiment, it is preferable that the adhesive strength after a high temperature and high humidity test in which a temperature of 85 ° C. and a humidity of 85% is left for 400 hours is 66.7% or more of the basic adhesive strength or 4 kgf / inch or more.

In an exemplary embodiment, in order to ensure stable long-term reliability, the adhesive strength after a high temperature and high humidity test in which a temperature of 60 ° C. and a humidity of 90% is left for 336 hours is 66.7% or higher of the basic adhesive strength or 4 kgf / inch or higher. It is preferable.

In an exemplary embodiment, the adhesive film includes a buffer adhesive layer and a moisture absorption adhesive layer, and the buffer adhesive layer is preferably a mixture of polyisobutylene and butyl rubber as a binder resin. Preference is given to using isobutylene alone.

In an exemplary embodiment, the adhesive layer of the adhesive film preferably includes two or more types of DCPD-based tackifiers having different softening points.

Exemplary embodiments of the present invention also provide an organic electronic device encapsulant comprising the above-described organic electronic device encapsulation adhesive film.

Exemplary embodiments of the present invention provide a method of encapsulating an organic electronic device by encapsulating an organic electronic device with the organic electronic device encapsulant described above.

Exemplary embodiments of the present invention also provide an organic electronic device sealed with the organic electronic device encapsulant described above.

According to the exemplary embodiments of the present invention, adhesion between the organic electronic device and the encapsulant at room temperature is excellent, further stable long-term reliability can be obtained, and the organic electronic device manufacturing yield can be prevented from being lowered.

In other words, when organic electronic devices such as OLED panels are manufactured, if the adhesion between the organic electronic device and the adhesive layer of the adhesive film for encapsulation is poor, problems such as adhesion bubbles, unbonded parts, and lifting occur, resulting in a decrease in manufacturing yield. Insufficient properties such as shear stress, coefficient of thermal expansion (CTE), resin flow, basic adhesion, and retention can cause deterioration in the long-term reliability of the applied product. By improving these problems by optimizing the rheological properties of the composite material, it is possible to improve adhesion at room temperature, improve long-term reliability, and prevent a decrease in the yield of organic electronic devices.

1 is a schematic view showing each layer of an organic electronic device encapsulant according to an embodiment of the present invention.

In the present specification, adhesion or panel adhesion refers to adhesion when an encapsulant (or may be referred to as an encapsulation layer or an encapsulant film) is attached to an OLED panel or glass by applying pressure at room temperature. The encapsulant includes, for example, a moisture absorption adhesive layer and a buffer adhesive layer when viewed from the outermost surface, and may further include a barrier layer such as a metal substrate.

During bonding, the surface of the buffer adhesive layer is the side in contact with the organic electronic device, that is, the surface bonded to the OLED panel or glass. In the bonding process, there must be no bubbles, unbonded parts, and lifting during the initial bonding, and after bonding, the initial physical properties must be maintained without growing bubbles and bubble traps to determine that there is no problem in bonding.

In addition, when there is substantially no generation of air bubbles (bubbles in the initial stages of adhesion and advanced air bubbles after adhesion), and/or there are no problems with appearance defects such as foreign matter or dents, it can be determined that adhesion is very excellent.

Substantially no generation of the above air bubbles means that there are no air bubbles (0) from the beginning of coalescence or that the number of air bubbles at the beginning of coalescence is 100/m ² or less, but becomes 10/m ² or less after 72 hours.

In the present specification, reliability refers to the physical properties of whether or not the physical properties necessary for the normal operation of the applied panel, that is, the encapsulated product, are secured when the panel is driven in a state where the encapsulant film is embedded as a component in the display panel, for example, excellent panel adhesion, It means securing physical properties, including good adhesion, moisture and oxygen barrier properties, and no discoloration of the bezel of the OLED panel.

In this specification, long-term reliability refers to the physical properties of whether or not the above reliability is maintained even when the applied product (sealed product) is driven for more than a certain period of time in various environments (high temperature, high humidity, low temperature or rapid temperature change, etc.) do.

In the present specification, resin flow is a phenomenon in which an organic electronic device such as an OLED panel and an encapsulation adhesive layer located in the middle of a metal substrate are stretched in the horizontal direction by temperature and pressure and become larger than both substrates (organic electronic device and metal substrate) and protrude. it means. If the resin flow is large, contamination by organic matter may occur on the panel.

In the present specification, when a part "includes" a certain component, it means that it may further include other components, not excluding other components unless otherwise stated.

Hereinafter, exemplary implementations of the present invention will be described in detail with reference to the accompanying drawings.

Organic electronic device encapsulant of exemplary embodiments of the present invention, a buffer adhesive layer made of an adhesive composition and located on the organic electronic device side; and a moisture adsorption adhesive layer made of an adhesive composition, further including a moisture adsorbent, and positioned on a barrier layer side of a metal substrate. .

1 is a schematic diagram showing each layer of an organic electronic device encapsulant according to an embodiment of the present invention.

As shown in FIG. 1, the organic electronic device encapsulant [entire encapsulation layer 6] includes an organic electronic device encapsulation adhesive film [or encapsulation adhesive layer 5], and the adhesive film consists of two layers. In this case, the moisture absorption adhesive layer (1), which is an adhesive layer containing a moisture absorbent, is bonded to the metal substrate (3), and the buffer adhesive layer (2), which does not contain a moisture absorbent and protects the panel, is an organic electronic device such as an OLED panel (4). It is composed of a structure attached to the side.

When the organic electronic device encapsulant is bonded to the organic electronic device side such as the OLED panel, the side of the buffer adhesive layer (1) becomes the bonding surface with the organic electronic device side such as the OLED panel. adhesion failure may occur.

Accordingly, the present inventors evaluated various factors related to this according to the composition of the adhesive, and through a number of trials and errors over a long period of time, it was confirmed that adhesion and long-term reliability are related to rheological properties. Furthermore, it was confirmed that long-term reliability is better and product lifespan can be increased only when various physical properties such as modulus, viscosity, expansion coefficient, resin flow, shear stress, CTE, basic adhesion, and retention are additionally secured.

In exemplary embodiments, in order to have excellent room temperature adhesion, the storage modulus, which is an in-phase component of the dynamic modulus of the buffer adhesive layer 2, and the out-of-phase component, It was experimentally confirmed that Tan (delta), a ratio of Loss Modulus, of 1.2 or more and less than 1.8 at 25 ° C was excellent in adhesion.

In a non-limiting example, the Tan (delta) at 25 ° C is 1.20 or more, 1.21 or more, 1.22 or more, 1.23 or more, 1.24 or more, 1.25 or more, 1.26 or more, 1.27 or more, 1.28 or more, 1.29 or more, 1.30 or more, 1.31 1.32 or higher, 1.33 or higher, 1.34 or higher, 1.35 or higher, 1.36 or higher, 1.37 or higher, 1.38 or higher, 1.39 or higher, 1.40 or higher, 1.41 or higher, 1.42 or higher, 1.43 or higher, 1.44 or higher, 1.45 or higher, 1.46 or higher, 1.47 or higher, 1.48+, 1.49+, 1.50+, 1.51+, 1.52+, 1.53+, 1.54+, 1.55+, 1.56+, 1.57+, 1.58+, 1.59+, 1.60+, 1.61+, 1.62+, 1.63+, 1.64+ , 1.65 or more, 1.66 or more, 1.67 or more, 1.68 or more, 1.69 or more, 1.70 or more, 1.71 or more, 1.72 or more, 1.73 or more, 1.74 or more, 1.75 or more, or less than 1.80, 1.79 or less, 1.78 or less, 1.77 or less, 1.76 1.75 or less, 1.74 or less, 1.73 or less, 1.72 or less, 1.71 or less, 1.70 or less, 1.69 or less, 1.68 or less, 1.67 or less, 1.66 or less, 1.65 or less, 1.64 or less, 1.63 or less, 1.62 or less, 1.61 or less, 1.60 or less, 1.59 or less, 1.58 or less, 1.57 or less, 1.56 or less, 1.55 or less, 1.54 or less, 1.53 or less, 1.52 or less, 1.51 or less, 1.50 or less, 1.49 or less, 1.48 or less, 1.47 or less, 1.46 or less, 1.45 or less, 1.44 or less, 1.43 or less , 1.42 or less, 1.41 or less, 1.30 or less, 1.29 or less, 1.28 or less, 1.27 or less, 1.26 or less, 1.25 or less, 1.24 or less, 1.23 or less, 1.22 or less, 1.21 or less.

In relation to this, the definitions of storage modulus, loss modulus and Tan (delta) are as follows.

- Storage modulus G'=G*cos(delta)

- Loss modulus G”=G*sin(delta)

- Tan(delta)=G”/G'

- delta = phase difference between stress input and displacement response

- G = shear load

In exemplary embodiments, the temperature at which the maximum value of Tan(delta), which is the dynamic glass transition temperature (Tg) (ie, Tan'(delta)=0, which is the differential value of Tan(delta)), is the cementation temperature. It was confirmed that room temperature adhesion improves when it is close to room temperature, which is the time temperature. Therefore, it is appropriate that the temperature at the maximum value of Tan (delta) is located at 20 to 27 ° C.

In dynamic viscoelasticity, the temperature at the maximum value of Tan (delta) is Tg, which is the temperature at which molecular motion of the polymer chain becomes active, and at a temperature away from Tg, it means that the molecular resistance of the polymer increases.

It can be understood that it is advantageous that the temperature at the maximum value of Tan (delta), which is dominated by the viscous region, which is the property of flowing sticky rather than the elasticity to return to its original shape, corresponds to the temperature at the time of bonding.

In a non-limiting example, the maximum value of the Tan (delta) is 20 ° C or more, 21 ° C or more, 22 ° C or more, 23 ° C or more, 24 ° C or more, 25 ° C or more, 26 ° C or more, or 27 ° C or less, 26 ° C It may be 25°C or less, 24°C or less, 23°C or less, 22°C or less, or 21°C or less.

If the temperature is less than 20 ° C, long-term reliability may be deteriorated, and if the temperature exceeds 27 ° C, the room temperature adhesion property is deteriorated, and a heating process may be required during adhesion.

In exemplary embodiments, in order to have excellent room temperature adhesion, the viscosity of the buffer adhesive layer 2 bonded to the side of an organic electronic device such as an OLED panel at 25° C. is in the range of 11 to 300,000 Pa·s. It is appropriate.

In non-limiting examples, the viscosity of the buffer adhesive layer 2 at 25° C. is 110,000 Pa s or more, 120,000 Pa s or more, 130,000 Pa s or more, 140,000 Pa s or more, 150,000 Pa s or more. 160,000 Pa s or more, 170,000 Pa s or more, 180,000 Pa s or more, 190,000 Pa s or more, 200,000 Pa s or more, 210,000 Pa s or more, 220,000 Pa s or more , 230,000 Pa s or more, 240,000 Pa s or more, 250,000 Pa s or more, 260,000 Pa s or more, 270,000 Pa s or more, 280,000 Pa s or more, 290,000 Pa s or more, or , 300,000 Pa s or less, 290,000 Pa s or less, 280,000 Pa s or less, 270,000 Pa s or less, 260,000 Pa s or less, 250,000 Pa s or less, 240,000 Pa s or less, 230,000 Pa s or less, 220,000 Pa s or less, 210,000 Pa s or less, 200,000 Pa s or less, 190,000 Pa s or less, 180,000 Pa s or less, 170,000 Pa s or less, 16 10,000 Pa·s or less, 150,000 Pa·s or less, 140,000 Pa·s or less, 130,000 Pa·s or less, or 120,000 Pa·s or less.

When the viscosity of the buffer adhesive layer is less than 110,000 Pa s, it has a low modulus, so the characteristics of protecting the organic electronic device from the outside deteriorate and long-term reliability deteriorates, and the viscosity of the buffer adhesive layer is 300,000 Pa s If it is exceeded, flowability at room temperature is lowered, and air traps between the adhesive surface and the adhesive layer may easily occur, resulting in deterioration in adhesion.

In exemplary embodiments, the 25 ° C viscosity of the entire adhesive layer including the buffer adhesive layer and the moisture absorption adhesive layer is appropriately in the range of 150,000 to 550,000 Pa·s.

In non-limiting examples, the viscosity of the entire adhesive layer at 25 ° C is 150,000 Pa s or more, 160,000 Pa s or more, 170,000 Pa s or more, 180,000 Pa s or more, 190,000 Pa s or more, 20 10,000 Pa s or more, 210,000 Pa s or more, 220,000 Pa s or more, 230,000 Pa s or more, 240,000 Pa s or more, 250,000 Pa s or more, 260,000 Pa s or more, 270,000 Pa s or more, 280,000 Pa s or more, 290,000 Pa s or more, 300,000 Pa s or more, 310,000 Pa s or more, 320,000 Pa s or more, 330,000 Pa s or more, 340,000 Pa s or more, 350,000 Pa s or more, 360,000 Pa s or more, 370,000 Pa s or more, 380,000 Pa s or more, 390,000 Pa s or more, 400,000 Pa s or more, 410,000 Pa s or more s or more, 420,000 Pa s or more, 430,000 Pa s or more, 440,000 Pa s or more, 450,000 Pa s or more, 460,000 Pa s or more, 470,000 Pa s or more, 480,000 Pa s 490,000 Pa s or more, 500,000 Pa s or more, 510,000 Pa s or more, 520,000 Pa s or more, 530,000 Pa s or more, 540,000 Pa s or more, 550,000 Pa s or more , 560,000 Pa s or more, 570,000 Pa s or more, 580,000 Pa s or more, 590,000 Pa s or more, or 600,000 Pa s or less, 590,000 Pa s or less, 580,000 Pa s or less or less, 570,000 Pa s or less, 560,000 Pa s or less, 550,000 Pa s or less, 540,000 Pa s or less, 530,000 Pa s or less, 520,000 Pa s or less, 510,000 Pa s or less , 500,000 Pa s or less, 490,000 Pa s or less, 480,000 Pa s or less, 470,000 Pa s or less, 460,000 Pa s or less, 450,000 Pa s or less, 440,000 Pa s or less, 430,000 Pa s or less, 420,000 Pa s or less, 410,000 Pa s or less, 400,000 Pa s or less, 390,000 Pa s or less, 380,000 Pa s or less, 370,000 Pa s or less, 36 10,000 Pa s or less, 350,000 Pa s or less, 340,000 Pa s or less, 330,000 Pa s or less, 320,000 Pa s or less, 310,000 Pa s or less, 300,000 Pa s or less, 290,000 Pa s or less, 280,000 Pa s or less, 270,000 Pa s or less, 260,000 Pa s or less, 250,000 Pa s or less, 240,000 Pa s or less, 230,000 Pa s or less, 220,000 Pa ·s or less, 210,000 Pa·s or less, 200,000 Pa·s or less, 190,000 Pa·s or less, 180,000 Pa·s or less, 170,000 Pa·s or less, or 160,000 Pa·s or less.

If the viscosity of the entire encapsulation adhesive layer is less than 150,000 Pa s, it has a low modulus, so there is a problem in that the characteristics of protecting the organic electronic device from the outside are deteriorated, and if the viscosity of the buffer adhesive layer exceeds 550,000 Pa s, room temperature The flowability in is lowered, and bubble traps between the adhesive layer and the adhesive layer can easily occur, resulting in deterioration in adhesion.

On the other hand, in exemplary embodiments, in order to secure basic reliability and long-term reliability of sealed products, a coefficient of thermal expansion (CTE) at 60 ° C. is required to be 1,000 ppm or less, preferably 10 to 1,000 ppm. .

In non-limiting examples, the coefficient of thermal expansion (CTE) value is 1000 ppm or less, 950 ppm or less, 900 ppm or less, 850 ppm or less, 800 ppm or less, 750 ppm or less, 700 ppm or less, 650 ppm or less, 600 ppm or less, 550 ppm or less, 540 ppm or less, 530 ppm or less , 520 ppm or less, 510 ppm or less, 500 ppm or less, 490 ppm or less, 480 ppm or less, 470 ppm or less, 460 ppm or less, 450 ppm or less, or 450 ppm or more, 460 ppm or more, 470 ppm or more, 480 ppm or more, 490 ppm or more, 500 ppm or more, 510 ppm or higher, 520 ppm or higher , 530 ppm or more, 540 ppm or more, 550 ppm or more, 600 ppm or more, 650 ppm or more, 700 ppm or more, 750 ppm or more, 800 ppm or more, 850 ppm or more, 900 ppm or more, or 950 ppm or more.

The coefficient of thermal expansion is the rate of expansion of the volume per unit volume according to the temperature. If it exceeds 1000 ppm, warpage of the panel may occur, and durability may be deteriorated when external temperature changes.

6mm 이상이 적합하다. 전단응력 값이 낮으면, 접착제의 응집력이 약한 것으로, 응집파괴가 쉽게 발생할 수 있다. In exemplary embodiments, the shear stress measured by a universal testing machine (UTM) at a speed of 300 mm per minute is 3 kg/min to ensure basic reliability and long-term reliability of the encapsulated product.

6 mm or more is suitable. If the shear stress value is low, the cohesive force of the adhesive is weak, and cohesive failure can easily occur.

6mm 이상, 3.5 kg/

6mm 이상, 4 kg/

6mm 이상, 4.5 kg/

6mm 이상, 5 kg/

6mm 이상, 5.5 kg/

6mm 이상, 6 kg/

6mm 이상일 수 있다.In a non-limiting example, the shear stress is 3 kg/

6 mm or more, 3.5 kg/

6 mm or more, 4 kg/

6 mm or more, 4.5 kg/

6 mm or more, 5 kg/

6 mm or more, 5.5 kg/

6 mm or more, 6 kg/

It may be 6 mm or more.

In exemplary embodiments, in order to ensure basic reliability and long-term reliability of a sealed product, it is appropriate that the 180° basic adhesive strength measured by UTM at a speed of 300 mm per minute should exceed 6 kgf/inch. When the basic adhesive strength is as high as more than 6kgf/inch, it is easy to bond metal and panel and maintain long-term reliability of the product.

In non-limiting examples, the basic adhesion is 6.1 kgf / inch or more, 6.2 kgf / inch or more, 6.3 kgf / inch or more, 6.4 kgf / inch or more, 6.5 kgf / inch or more, 6.6 kgf / inch or more, 6.7 kgf / inch or more 6.8 kgf/inch or more, 6.9 kgf/inch or more, 7.0 kgf/inch or more, 7.1 kgf/inch or more, 7.2 kgf/inch or more, 7.3 kgf/inch or more, 7.4 kgf/inch or more, 7.5 kgf/inch or more, 7.6 kgf/inch or more, 7.7 kgf/inch or more, 7.8 kgf/inch or more, 7.9 kgf/inch or more, 8.0 kgf/inch or more, 8.1 kgf/inch or more, 8.2 kgf/inch or more, 8.3 kgf/inch or more, 8.4 kgf /inch or more, 8.5kgf/inch or more, 8.6kgf/inch or more, 8.7kgf/inch or more, 8.8kgf/inch or more, 8.9kgf/inch or more, 9.0kgf/inch or more, 9.1kgf/inch or more, 9.2kgf/inch 9.3 kgf/inch or more, 9.4 kgf/inch or more, 9.5 kgf/inch or more, 9.6 kgf/inch or more, 9.7 kgf/inch or more, 9.8 kgf/inch or more, 9.9 kgf/inch or more, 10.0 kgf/inch or more, 10.1kgf/inch or more, 10.2kgf/inch or more, 10.3kgf/inch or more, 10.4kgf/inch or more, 10.5kgf/inch or more, 10.6kgf/inch or more, 10.7kgf/inch or more, 10.8kgf/inch or more, 10.9kgf / inch or more, may be 11.0 kgf / inch or more.

In addition, in exemplary embodiments, in order to ensure stable long-term reliability, when the adhesive strength before low temperature, high temperature, thermal shock, high temperature and high humidity (accelerated life) test is 100%, the adhesive strength after the test is 66.7% or more (4 kgf / inch or more) this should be maintained The adhesive strength of 66.7% or more (more than 4kgf/inch) compared to the initial level must be maintained to secure the reliability of the sealed product in low and high temperatures, rapid temperature changes and accelerated life environments that may be encountered during transportation/storage/use.

In an exemplary embodiment, as described above, the organic electronic device encapsulant may include a buffer adhesive layer made of an adhesive composition; And a moisture adsorption adhesive layer further comprising a moisture adsorbent in the adhesive composition; And it may further include a barrier layer such as a metal substrate located on the side of the moisture absorption adhesive layer.

Since the above-described physical properties are determined according to the types and ratios of the components of the adhesive composition used in the adhesive layer, they can be adjusted through tests according to the types and ratios of the components of various compositions.

In an exemplary embodiment, the adhesive layer composition may include a polyolefin-based binder as a base resin, a tackifier, an acrylic monomer, and a photoinitiator.

In one exemplary embodiment, the polyolefin-based binder of the adhesive composition of the buffer adhesive layer may include at least one of polyisobutylene and butyl rubber having excellent water resistance, and preferably has a weight ratio of 9:1 to 2:8 can be included with

In one exemplary embodiment, the adhesive composition of the moisture absorption adhesive layer may use polyisobutylene alone.

In an exemplary embodiment, the molecular weight of the binder resin may be 100,000 to 2 million Mw, preferably 500,000 to 1.6 million Mw, more preferably 600,000 to 1.5 million Mw.

Here, the molecular weight means the weight average molecular weight, For example, the weight average molecular weight may be measured by a molecular weight measurement instrument such as GPC (Gel permeation chromatography), which is commonly used.

When the molecular weight is lower than 500,000 Mw, the property of binding the hygroscopic filler may deteriorate, the moisture barrier property of the adhesive film may deteriorate, and the adhesive strength may also deteriorate. When the molecular weight exceeds 1.6 million Mw, compatibility with other raw materials may be deteriorated and adhesion with OLED panels may be deteriorated.

In non-limiting examples, the molecular weight is 500,000 Mw or more, 600,000 Mw or more, 700,000 Mw or more, 800,000 Mw or more, 900,000 Mw or more, 1 million Mw or more, 1.1 million Mw or more, 1.2 million Mw or more, 130 It may be 10,000 Mw or more, 1.4 million Mw or more, or 1.5 million Mw or more. or 1.6 million Mw or less, 1.5 million Mw or less, 1.4 million Mw or less, 1.3 million Mw or less, 1.2 million Mw or less, 1.1 million Mw or less, 1 million Mw or less, 900,000 Mw or less, 800,000 Mw or less, 700,000 Mw Or less, it may be 600,000 Mw or less.

In an exemplary embodiment, the composition has a softening point of greater than or equal to 90°C and less than 150°C, or preferably 95°C to 140°C or 105°C to 140°C, more preferably 95°C to 135°C or 95°C to 125°C. Or 105 ℃ ~ 135 ℃ or 105 ℃ ~ 125 ℃ may further include a tackifier.

In non-limiting examples, the softening point is 90 ° C or higher, 91 ° C or higher, 92 ° C or higher, 93 ° C or higher, 94 ° C or higher, 95 ° C or higher, 96 ° C or higher, 97 ° C or higher, 98 ° C or higher, 99 ° C or higher, 100 °C or more, 101 °C or more, 102 °C or more, 103 °C or more, 104 °C or more, 105 °C or more, 106 °C or more, 107 °C or more, 108 °C or more, 109 °C or more, 120 °C or more, 121 °C or more, 122 °C or more , 123 ° C or more, 124 ° C or more, 125 ° C or more, 126 ° C or more, 127 ° C or more, 128 ° C or more, 129 ° C or more, 130 ° C or more, 131 ° C or more, 132 ° C or more, 133 ° C or more, 134 ° C or more, 135 °C or more, 136 °C or more, 137 °C or more, 138 °C or more, 139 °C or more, 140 °C or more, 141 °C or more, 142 °C or more, 143 °C or more, 144 °C or more, 145 °C or more, 146 °C or more, 147 °C or more , 148 ° C or higher, may be 149 ° C or higher. Alternatively, the softening point is less than 150 ° C, less than 149 ° C, less than 148 ° C, less than 147 ° C, less than 146 ° C, less than 145 ° C, less than 144 ° C, less than 143 ° C, less than 142 ° C, less than 141 ° C, less than 140 ° C, 139 °C or less, 138 °C or less, 137 °C or less, 136 °C or less, 135 °C or less, 134 °C or less, 133 °C or less, 132 °C or less, 131 °C or less, 130 °C or less, 129 °C or less, 128 °C or less, 127 °C or less , 126℃ or less, 125℃ or less, 124℃ or less, 123℃ or less, 122℃ or less, 121℃ or less, 120℃ or less, 119℃ or less, 118℃ or less, 117℃ or less, 116℃ or less, 115℃ or less, 114 °C or less, 113 °C or less, 112 °C or less, 111 °C or less, 110 °C or less, 109 °C or less, 108 °C or less, 107 °C or less, 106 °C or less, 105 °C or less, 104 °C or less, 103 °C or less, 102 °C or less , 101 ℃ or less, 100 ℃ or less, 99 ℃ or less, 98 ℃ or less, 97 ℃ or less, 96 ℃ or less, 95 ℃ or less, 94 ℃ or less, 93 ℃ or less, 92 ℃ or less, 91 ℃ or less can be used.

In a non-limiting example, the tackifier is 90 ° C. or more and less than 150 ° C., or preferably 95 ° C. to 140 ° C., more preferably petroleum hydrogenated DCPD (Dicyclopentadiene), which has excellent adhesive strength and water resistance, to enhance adhesive properties. One having a softening point of 95°C to 135°C may be used, and preferably two or more types having different softening points may be used. When two or more types with different softening points are used than when used alone, the physical properties expressed according to the softening point play a complementary role within a specific temperature range, which is preferable for strengthening properties such as adhesive strength, heat resistance, and cohesiveness.

When the softening point is less than 90° C., the moisture barrier properties of the adhesive film may deteriorate. The higher the softening point of the tackifier, the better the moisture barrier properties, but when the temperature is 150° C. or higher, the viscosity and modulus increase, and adhesion and adhesion may deteriorate.

In an exemplary embodiment, the content of the tackifier is greater than 20 parts by weight and less than 160 parts by weight, or preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder.

When the tackifier is contained in an amount of 20 parts by weight or less, a decrease in adhesive strength and a decrease in moisture barrier properties may occur, and a modulus of 160 parts by weight or more and a viscosity become too large, resulting in poor adhesion, and high adhesive strength, but may easily cause peeling between layers. there is.

In non-limiting examples, the tackifier is greater than 20 parts by weight, 30 parts by weight or more, 40 parts by weight or more, 50 parts by weight or more, 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, 90 parts by weight or more , 100 parts by weight or more, 110 parts by weight or more, 120 parts by weight or more, 130 parts by weight or more, 140 parts by weight or more, may be 150 parts by weight or more. Or the tackifier is less than 160 parts by weight, 150 parts by weight or less, 140 parts by weight or less, 130 parts by weight or less, 120 parts by weight or less, 110 parts by weight or less, 100 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less , 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, may be 30 parts by weight or less.

In one exemplary embodiment, the composition may include at least one of a monofunctional acrylic monomer and a multifunctional acrylic monomer.

In one exemplary embodiment, the monofunctional acrylic monomer is not particularly limited as long as it is a monofunctional acrylic monomer. In addition, the monofunctional acrylic monomer may be included in more than 5 parts by weight and less than 20 parts by weight based on 100 parts by weight of the binder. In the case of 5 parts by weight or less and 20 parts by weight or more compared to 100 parts by weight of the binder, a decrease in adhesive strength may occur.

In non-limiting examples, the monofunctional acrylic monomer is greater than 5 parts by weight, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, 10 parts by weight or more, 11 parts by weight or more, 12 parts by weight Or more, 13 parts by weight or more, 14 parts by weight or more, 15 parts by weight or more, 16 parts by weight or more, 17 parts by weight or more, 18 parts by weight or more, may be 19 parts by weight or more. Alternatively, the monofunctional acrylic monomer is less than 20 parts by weight, 19 parts by weight or less, 18 parts by weight or less, 17 parts by weight or less, 16 parts by weight or less, 15 parts by weight or less, 14 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less Or less, 11 parts by weight or less, 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, may be 6 parts by weight or less.

In a non-limiting example, the monofunctional acrylic monomer may be trimethylolpropane (EO)n triacrylate, caprolactone acrylate, or polypropylene glycol monomethacrylate. ), Cyclic trimethylolpropane formal Acrylate, Phenoxy benzyl Acrylate, 3,3,5-trimethyl cyclohexyl Acrylate , Isobornyl Acrylate, o-phenylphenol EO Acrylate, 4-tert-butylcyclohexyl acrylate, Benzyl Acrylate ), benzyl methacrylate, lauryl acrylate [Lauryl Acrylate (eg, LA-C12,13)], lauryl methacrylate [Lauryl Methacrylate (eg, LMA-C12,13)], tridecyl Tridecyl Acrylate, Lauryl Tetradecyl Methacrylate, Isodecyl Acrylate, Isodecyl Methacrylate, Phenol (EO) Acrylate Acrylate], Phenoxyethyl Methacrylate, Phenol (EO)2 Acrylate, Phenol (EO)4 Acrylate, Tetrahydrofurfuryl Acrylate (Tetrahydrofurfuryl Acrylate), Tetrahydrofurfuryl Methacrylate (Tetrahydrofurfuryl Methacrylate), Nonyl Phenol (PO)2 Acrylate [Nonyl Phenol (PO)2 Acrylate], Nonyl Phenol (EO)4 Acrylate [Nonyl Phenol (EO) )4 Acrylate], Nonyl Phenol (EO)8 Acrylate [Nonyl Phenol (EO)8 Acrylate], Ethoxy Ethoxy Ethyl Acrylate, Stearyl Acrylate, Stearyl Methacryl Late (Stearyl Methacrylate), methoxy polyethylene glycol methacrylate (Methoxy PEG Methacrylate, for example, Methoxy PEG 600 Methacrylate) may be used, but is not limited thereto.

In a non-limiting example, as the monofunctional acrylic monomer, an acrylate series having a relatively fast curing rate may be more preferable than a methacrylate series.

In an exemplary embodiment, the multifunctional acrylic monomer may be, for example, bifunctional, trifunctional, tetrafunctional, pentafunctional, or hexafunctional acrylic monomer, and in terms of water permeation rate, a bifunctional acrylic monomer is preferably used. can be used

The multifunctional acrylic monomer is included in an amount greater than 2.5 parts by weight and less than 15 parts by weight based on 100 parts by weight of the binder. Under the conditions of 2.5 parts by weight or less and 15 parts by weight or more, adhesive strength may decrease, and when it is 15 parts by weight or more, the viscosity becomes too large and the adhesion is poor, and interlayer peeling may easily occur.

In a non-limiting example, the multifunctional acrylic monomer is greater than 2.5 parts by weight, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight based on 100 parts by weight of the binder. Part or more, 9 parts by weight or more, 10 parts by weight or more, 11 parts by weight or more, 12 parts by weight or more, 13 parts by weight or more, may be 14 parts by weight or more. Alternatively, the polyfunctional acrylic monomer is less than 15 parts by weight, 14 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less, 11 parts by weight or less, 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less It may be 6 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, or 3 parts by weight or less.

In a non-limiting example, the multifunctional acrylic monomer is 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1 ,6-hexanediol (EO)n diacrylate [1,6-Hexanediol (EO)n Diacrylate], polypropylene glycol diacrylate (e.g. Polypropylene glycol 400 Diacrylate), 1,4-butanediol dimetha acrylate (1,4-Butanediol Dimethacrylate), polypropylene glycol (EO)6 dimethacrylate (e.g. Polypropylene glycol 700 (EO)6 Dimethacrylate), hydroxy pivalic acid neopentyl glycol Hydroxy pivalic acid neopentyl glycol Diacrylate, Bisphenol A (EO)10 Diacrylate, Bisphenol A (EO)10 Dimethacrylate, Neopentyl glycol dimethacrylate, Neopentyl glycol (PO)2 diacrylate, Tripropylene glycol diacrylate, Ethylene glycol dimethacrylate Ethylene glycol Dimethacrylate, Dipropylene glycol Diacrylate, Bisphenol A (EO)30 Diacrylate, Bisphenol A (EO)30 Dimethacrylate [Bisphenol A (EO)30 Dimethacrylate], Diethylene glycol Dimethacrylate, Triethylene glycol Diacrylate, Triethylene glycol Dimethacrylate, Tetraethylene Glycol Dimethacrylate [Tetraethylene glycol Dimethacrylate], Bisphenol A (EO)4 Diacrylate [Bisphenol A (EO)4 Diacrylate], Bisphenol A (EO)4 Dimethacrylate [Bisphenol A (EO)4 Dimethacrylate], Bisphenol A (EO)3 Diacrylate [Bisphenol A (EO)3 Diacrylate], Bisphenol A (EO)3 Dimethacrylate [Bisphenol A (EO)3 Dimethacrylate], 1,3-Butylene Glycol Dimethacrylate [1,3-Butylene glycol Dimethacrylate], Tricyclodecane dimethanol Diacrylate, Tetraethylene glycol Diacrylate, Polyethylene glycol Diacrylate (e.g. Polyethylene glycol 400 Diacrylate), polyethylene glycol dimethacrylate (e.g. Polyethylene glycol 400 Dimethacrylate, or Polyethylene glycol 200 Dimethacrylate, Polyethylene glycol 600 Dimethacrylate), polyethylene glycol diacrylate (e.g. Polyethylene glycol 200 Diacrylate, Polyethylene glycol 300 Diacrylate, Polyethylene glycol 600 Diacrylate), or bisphenol F (EO) 4 diacrylate [Bisphenol F (EO) 4 Diacrylate], but is not limited thereto.

In a non-limiting example, as the multifunctional acrylic monomer, an acrylate based monomer having a relatively fast curing speed may be more preferable than a methacrylate based monomer.

In an exemplary embodiment, the composition may further include a photoinitiator. The photoinitiator generates free radicals and is not particularly limited in type, and products that react to a short wavelength of 200 nm to a long wavelength of 400 nm can be widely used.

For example, photoinitiators include benzoin methyl ether, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide, α,α-methoxy-α-hydride Roxyacetophenone, 2-benzoyl-2-(dimethylamino)-1-[4-(4-morphonyl)phenyl]-1-butanone, 2,2-dimethoxy-2-phenylacetophenone, oxime ester system It may include one or more selected from the group consisting of and the like. Also, for example, it may be 1-Hydroxy-cyclohexyl-phenyl-ketone or Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide, preferably Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (common name TPO). can

During UV irradiation, free radicals are generated to react to the double bond of acrylate, which itself participates in the reaction and causes photocuring, so the content ratio with acrylate can be calculated, but the content ratio to the binder usage can be determined.

In an exemplary embodiment, the photoinitiator is used in an amount greater than 5 parts by weight and less than 20 parts by weight based on 100 parts by weight of the binder. If it is less than 5 parts by weight, the crosslinking density is low, so adhesive strength, moisture barrier properties, and long-term reliability all decrease. If the content is more than 20 parts by weight, poor film appearance may occur due to overcuring and uncured residues, and long-term reliability may also decrease. there is.

In non-limiting examples, the photoinitiator is greater than 5 parts by weight, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, 10 parts by weight or more, 11 parts by weight or more, 12 parts by weight or more, 13 It may be 14 parts by weight or more, 15 parts by weight or more, 16 parts by weight or more, 17 parts by weight or more, 18 parts by weight or more, or 19 parts by weight or more. Or the photoinitiator is less than 20 parts by weight, 19 parts by weight or less, 18 parts by weight or less, 17 parts by weight or less, 16 parts by weight or less, 15 parts by weight or less, 14 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less, 11 It may be less than 10 parts by weight, less than 9 parts by weight, less than 8 parts by weight, less than 7 parts by weight, or less than 6 parts by weight.

In an exemplary embodiment, calcium oxide powder may be used for the moisture absorbing adhesive layer to absorb moisture and/or oxygen, and high-purity nickel may be additionally used to prevent occurrence of black spots on the panel during long-term operation.

On the other hand, exemplary embodiments of the present invention also provide a method for manufacturing an organic electronic device encapsulant comprising the step of forming the above-described adhesive film for encapsulation on a barrier layer such as a metal substrate.

In an exemplary embodiment, the method is to coat an adhesive composition that does not contain a moisture absorbent on a first release film (heavy release film), heat dry and cure, and then laminate a second release film (light release film). providing a pre-adhesive film having a buffer adhesive layer interposed therebetween;

After coating an adhesive composition containing a moisture absorbent on a third release film (light-peel release film), drying and curing by heating, removing the second release film (light-peel release film) from the first pre-adhesive film and exposed providing an adhesive film comprising a moisture absorption adhesive layer and a buffer adhesive layer by thermally laminating the surface; and

It may include; removing the third release film (light release film) from the adhesive film and providing an encapsulant by laminating the exposed surface with a barrier layer such as invar or a metal substrate such as aluminum.

Exemplary embodiments of the present invention also provide a method of encapsulating an organic electronic device by encapsulating an organic electronic device with the organic electronic device encapsulant described above.

Exemplary embodiments of the present invention also provide an organic electronic device sealed with the organic electronic device encapsulant described above.

Exemplary embodiments of the present invention are described in more detail through the following examples. Embodiments disclosed herein are illustrated for purposes of explanation only, and embodiments of the present invention may be implemented in various forms and should not be construed as being limited to the embodiments described herein.

Examples and comparative examples to be described later were prepared and evaluated corresponding to Experiments 1 to 8. The detailed evaluation contents of the said test are as follows.

[Experiment 1. Adhesion]

After preparing a sample by laminating the moisture absorption adhesive layer (1) side of the adhesive layer (3) with the metal substrate (3) at a temperature of 100 ° C with a roll laminator, the OLED panel and laminating equipment are used on the buffer adhesive layer (2) side. It was bonded at room temperature. After bonding, the bonding state after 72 hours was analyzed with the naked eye and non-destructive testing equipment for comprehensive evaluation. In the bonding process, it was determined that there was no problem in bonding when there were no bubbles, unbonded parts, and lifting during the initial bonding, and the initial physical properties were maintained without growing bubbles and bubble traps after bonding.

Specifically, after 72 hours after OLED panel bonding, when analyzed with the naked eye and non-destructive inspection equipment, if the bubble generation is excellent at 10/m ² or less, the bonding property is evaluated as O, and after 72 hours, the bubble generation is 10 /m ² In the case of exceeding, the adhesion property was evaluated as X.

In addition, in addition to air bubbles, when visually observed immediately after bonding, foreign matter and dents are absent, or even if there are, foreign matter, dents, or foreign matter and dent size (maximum length) achieve excellent appearance characteristics of 25 μm or less confirmed that it does.

[Experiment 2. Measurement of viscosity and modulus]

After laminating the moisture absorption adhesive layer (1) and the buffer adhesive layer (2) at a temperature of 60 ° C. to prepare the encapsulation adhesive layer (5), after removing the release film on both sides of the film, it is laminated to a thickness of 600 ~ 1000um, 10mm After punching to a size of x 10mm, analysis was performed under Oscillation Temp Ramp conditions at a heating rate of 5°C per minute from 0°C to 120°C with TA's ARES-G2 Rheometer analyzer. The strain was 0.1%, the frequency was 15 rad/s, and the rest was measured according to general analysis conditions. The viscosity and modulus of the buffer adhesive layer (2) were measured in the same manner as above except for using a specimen in which a single film of the buffer adhesive layer (2) was laminated at 600 to 1000 μm.

[Experiment 3. CTE (coefficient of thermal expansion) measurement]

After removing the release film on both sides of the laminated film of the moisture absorption adhesive layer (1) and the buffer adhesive layer (2) at a temperature of 60 ℃, the encapsulation adhesive layer (5) laminated to a thickness of 600 ~ 1000um, the size of 6mm x 10mm After punching, the CTE was measured with a TMA-SDTA-1 analyzer from Mettler Toledo at a temperature increase rate of 5 ° C per minute from 25 ° C to 100 ° C under the conditions of 0.01 N in tension mode, and the CTE at 60 ° C was measured as a standard. Other conditions were measured according to the standards of ASTM E831.

[Experiment 4. Shear stress measurement]

After laminating the moisture absorption adhesive layer (1) and the buffer adhesive layer (2) at a temperature of 60 ° C. to prepare the sealing adhesive layer (5), the film is punched out in a circular shape with a diameter of 6 mm, and then the moisture absorption adhesive layer (1) is released After removing the film, the entire encapsulation layer (6) is prepared by bonding the moisture absorption adhesive layer and the cleaned metal substrate (3) with heat at 100 ° C, and then cut into a width of 1 inch x length of 140 mm, and then the opposite side, the buffer adhesive layer (2) After removing the release film, laminating to 75mmx125mm Alkali free glass at room temperature, shear stress was evaluated by pulling the entire encapsulation layer (6) at 300mm/min using a universal testing machine (UTM, AGS-1KNX, SHIMADZU) .

[Experiment 5. Basic adhesion measurement]

After removing the release film of the water absorption adhesive layer (1), the film of the encapsulation adhesive layer (5), in which the moisture absorption adhesive layer (1) and the buffer adhesive layer (2) are laminated at a temperature of 60 ° C, is heated to 100 ° C. After bonding with heat and cutting to a width of 1 inch x length of 140 mm to prepare the entire encapsulation layer (6), after removing the release film of the buffer adhesive layer (2), which is the opposite side, laminating to 75 mm x 125 mm Alkali free glass at room temperature, all-purpose material Using a tester (UTM, AGS-1KNX, SHIMADZU Co.), the entire encapsulation layer (6) was bent at 180 ° and peeled at 300 mm / min to evaluate the adhesive strength.

[Experiment 6. Measurement of retention force]

In order to measure the retention power of low-temperature preservation, high-temperature preservation, thermal shock, and high-temperature and high-humidity (accelerated life) environments, after leaving it in the chamber or constant temperature and humidity chamber below, the adhesive force of the specimen (same structure as the basic adhesive force measurement specimen) was measured. It was evaluated in the same way as the basic adhesive force measurement method.

- Low-temperature preservation test: left for 1000 hours in a freezing chamber at -20 ° C

- High-temperature preservation test: left in a high-temperature chamber at 60 ° C for 1000 hours

- Thermal shock test: 100 cycles of being left in a -20°C freezing chamber for 30 minutes, moving to a high-temperature chamber at 60°C, and then leaving it for 30 minutes are repeated.

- High temperature and high humidity test 1 (accelerated lifespan 1): left for 336 hours in a constant temperature and humidity chamber at 60℃ and 90% temperature and humidity

- High-temperature and high-humidity test 2 (accelerated lifespan 2): left for 400 hours in a constant temperature and humidity chamber at 85℃ and 85% temperature and humidity

[Experiment 7. Resin flow]

After removing the release film on both sides of the buffer adhesive layer (2), laminate them to prepare a sample with a thickness of 80±8um, punch out a 6mm circular shape, place the sample in the center between two sheets of 100mm x 100mm Alkali free glass, and incubate at room temperature. It was combined with a roll press. After pressing for 150 seconds at a pressure of 0.4 kg/cm ² on a flat press at 60° C., the change in diameter before/after was measured.

[Manufacture of encapsulant film (common)]

After blending and dispersing the compositions of Examples and Comparative Examples, the mixed solution was degassed after filtering to prepare a coating solution. Using a slot die or comma coater, apply the coating solution of the moisture absorption adhesive layer (1) and the buffer adhesive layer (2) respectively, heat-treat the solvent, dry it, and then irradiate UV with a light amount of 500mJ based on the 365nm wavelength band to cure it made it

When the evaluation of individual physical properties of the moisture absorption adhesive layer (1) or the buffer adhesive layer (2) was required, the physical properties of each film were analyzed, and the For physical property analysis, after removing the release film in the direction of the adhesive side of the filmed moisture absorption adhesive layer (1) and buffer adhesive layer (2), they are laminated with a roll laminator at a temperature of 60 ° C to produce an encapsulation adhesive layer (5). did

In order to evaluate adhesion, the release film on the surface of the moisture absorption adhesive layer (1) of the sealing adhesive layer (3) is removed, and the entire sealing layer (6) sample is prepared by laminating with the metal substrate (3) at a temperature of 100 ° C using a roll laminator, , After removing the release film on the opposite side, the side of the buffer adhesive layer (2) was laminated at room temperature using an OLED panel and automated lamination equipment.

[Examples and Comparative Examples]

[Example 1]

In Example 1, based on 100 weight of a binder in which polyisobutylene and butyl rubber are mixed at a weight ratio of 7:3, two types of tackifiers (DCPD) with softening points of 90 ° C and 125 ° C are A buffer adhesive layer (2 ) prepared 10 μm, mixed with 100% polyisobutylene binder, and using an adhesive composition containing CaO (calcium oxide) powder having a particle size of 2 to 4 μm based on D50 so that the rest was 44 wt% of the total solid content in the same composition as above Thus, a 40 μm water absorption adhesive layer (1) was prepared.

Each layer is mixed/dispersed with a coating solution dissolved in an organic solvent, then coated using a slot die coater or comma coater, then the solvent is removed, and after irradiation with a light amount of 500mJ based on the UV 365nm wavelength range, the two layers are It was thermally laminated at a temperature of 60° C. to form an encapsulation adhesive layer 5 including a buffer adhesive layer and a moisture absorption adhesive layer.

[Example 2]

An encapsulation adhesive layer 5 was prepared with the same composition as in Example 1, except that the weight ratio of the binder polyisobutylene and butyl rubber of the buffer adhesive layer 2 was set to 9:1.

[Example 3]

An encapsulation adhesive layer 5 was prepared with the same composition as in Example 1, except that the weight ratio of the binder polyisobutylene and butyl rubber of the buffer adhesive layer 2 was set to 2:8.

[Example 4]

An encapsulation adhesive layer 5 was prepared with the same composition as in Example 1, except that the size of CaO of the moisture absorption adhesive layer 1 was changed to 1-2 μm based on D50.

[Comparative Example 1]

The same composition as in Example 1, except that the mixed weight ratio of the binder polyisobutylene and butyl rubber of the buffer adhesive layer (2) was changed to 1:9, and the tackifier was increased from 80 parts by weight to 90 parts by weight. An encapsulation adhesive layer 5 was prepared.

[Comparative Example 2]

An encapsulation adhesive layer 5 was prepared with the same composition as in Example 1, except that butyl rubber was used as the binder for the moisture absorption adhesive layer 1 and the buffer adhesive layer 2.

[Comparative Example 3]

Based on 100 weight of a binder in which polyisobutylene and butyl rubber are mixed at a weight ratio of 4:6, two types of tackifiers (DCPD) with softening points of 90 ℃ and 125 ℃ are 3: 7 Mixed 80 parts by weight of the mixture, 30 parts by weight of a molecular weight (Mw) of 6 to 70,000 bifunctional urethane acrylic oligomer (Hydrogenated Polybutadiene backbone), 9 parts by weight of a bifunctional acrylic monomer (TCDDA), 5 parts by weight of a phosphorus-based photoinitiator (TPO) mixed A buffer adhesive layer (2) of 10 μm was prepared with the adhesive composition, and based on 100 weight of a binder in which polyisobutylene and butyl rubber were mixed at a weight ratio of 4: 6, 200 parts by weight of softening point 90 ° C. A tackifier (DCPD), 25 parts by weight of a molecular weight (Mw) of 6 to 70,000 bifunctional urethane acrylic oligomer (Hydrogenated Polybutadiene backbone), 5 parts by weight of a bifunctional acrylic monomer (TCDDA), 4 parts by weight of a phosphorus-based photoinitiator (TPO) are mixed A moisture absorption adhesive layer (1) of 40 μm was prepared using an adhesive composition in which CaO (calcium oxide) powder having a particle size of 3 μm was added to the composition so that the total solid content was 43 wt%.

Each layer is mixed/dispersed with a coating solution dissolved in an organic solvent, then coated using a slot die coater or comma coater, then the solvent is removed, and after irradiation with a light amount of 500mJ based on the UV 365nm wavelength range, the two layers are It was thermally laminated at a temperature of 60° C. to form an encapsulation adhesive layer 5 including a buffer adhesive layer and a moisture absorption adhesive layer.

[Comparative Example 4]

Based on 100 weight of polyisobutylene binder, 90 parts by weight of a mixture of two kinds of tackifiers (DCPD) with softening points of 90 ℃ and 125 ℃ in a 5: 5 ratio, 20 parts by weight of bifunctional acrylic monomer (TCDDA) , 10 μm of the buffer adhesive layer (2) was prepared with an adhesive composition in which 3 parts by weight of a phosphorus-based photoinitiator (TPO) was mixed, and based on 100 parts by weight of a polyisobutylene binder, 120 parts by weight of a tackifier with a softening point of 90 ° C. ( DCPD), 10 parts by weight of a bifunctional acrylic monomer (TCDDA), and 2 parts by weight of a phosphorus-based photoinitiator (TPO). Using an adhesive composition in which CaO (calcium oxide) powder with a particle size of 3 um was added so that 43 wt% of the total solid content was mixed. A 40 μm water absorption adhesive layer (1) was prepared.

Each layer is mixed/dispersed with a coating solution dissolved in an organic solvent, then coated using a slot die coater or comma coater, then the solvent is removed, and after irradiation with a light amount of 500mJ based on the UV 365nm wavelength range, the two layers are It was thermally laminated at a temperature of 60° C. to form an encapsulation adhesive layer 5 including a buffer adhesive layer and a moisture absorption adhesive layer.

On the other hand, the sealing adhesive layer 5 including the moisture adsorption adhesive layer 1 and the buffer adhesive layer 2 of the above examples and comparative examples was prepared as a specimen of the entire sealing layer 6 to fit the structure of each experiment 1 to 8 described above. Each was prepared and evaluated, and the results are shown in the table below.

Table 1 below shows the results of rheological properties related to adhesion.

division panel adhesion
Viscosity of the buffer adhesive layer at 25°C
(10 ⁴ Pa·s) Tan(δ) of Buffer Adhesion Layer 25℃
Buffer adhesive layer Tan (δ) maximum point temperature (℃)
Viscosity of the entire adhesive layer at 25°C
(10 ⁴ Pa·s)
resin
flow
(mm)
Example 1 O 18.5 1.42 23 39.9 6.5 Example 2 O 19.1 1.31 23 45.1 6.4 Example 3 O 16.3 1.58 22 32.5 6.7 Example 4 O 20.4 1.44 24 48 6.4 Comparative Example 1 X 10.1 1.80 28 56 7.1 Comparative Example 2 X 6.5 1.82 14 14 7.9 Comparative Example 3 X 4.8 1.19 15.3 61 8.8 Comparative Example 4 X 35.1 1.85 28 58 8.2

Table 2 below shows physical property results related to long-term reliability.

division CTE
(ppm) shear stress
(kgf
/φ6mm) basic adhesion
(kgf
/inch)
Retention ability after thermal shock
(kgf
/inch)
Low temperature (-20℃) retention ability
(kgf
/inch)
High temperature (60℃) holding power
(kgf
/inch)
60℃90% holding power
(kgf
/inch)
85℃85% holding power
(kgf
/inch)
Example 1 490 5.5 10.1 8.9 10.2 6.8 6.3 5.3 Example 2 450 5.1 8.7 7.7 8.7 6.1 6.1 5.3 Example 3 520 3.8 7.1 7.1 7.0 6.2 5.9 5.4 Example 4 480 5.6 10.2 9.1 10.3 6.8 5.5 6.4 Comparative Example 1 1080 2.9 4.3 3.7 3.9 3.9 3.7 3.1 Comparative Example 2 1820 2.8 4.1 3.6 3.3 3.6 3.5 2.8 Comparative Example 3 3860 2.7 5.9 3.9 3.6 2.9 2.5 2.1 Comparative Example 4 2100 2.9 6.0 5.0 3.9 3.2 3.1 2.9

Unlike the moisture and gas barrier properties of general polymers or organic materials, the glass and metal substrates 3 theoretically have zero air permeability, so moisture and gas do not penetrate into the large area of the front and rear surfaces. The OLED encapsulation adhesive layer (5) between the glass and the metal substrate (3) serves to delay moisture permeation on the side of the OLED, which is vulnerable to moisture, and forms a layer between the OLED glass (OLED panel side (4)) and the metal substrate (3). It serves to bond the layers. In the bonding process, which is the initial process of bonding them, it was determined that there was no problem in bonding when there were no bubbles, unbonded parts, and lifting during the initial bonding, and the initial physical properties were maintained without growing bubbles and bubble traps after bonding.

The rheological properties affecting the cohesion and the physical properties related to the long-term reliability were confirmed through various experiments.

For good room temperature bonding, the room temperature viscosity of the buffer adhesive layer is 110,000 to 300,000 Pa S, and the viscosity of the entire adhesive layer is 150,000 to 550,000 Pa S. When the 25°C value of delta) was 1.2 or more and less than 1.8, it was possible to secure good room temperature adhesion. It can be seen that the room temperature adhesion is advantageous when the viscosity to flow is slightly greater than the elasticity to maintain the shape.

In addition, the maximum value of Tan (delta), which can be considered as the rheological glass transition temperature (Tg), was 20 ~ 27 ℃, which was found to be advantageous as it was closer to room temperature. Resin flow is also considered to be related to adhesion.

As in the examples, the composition having high basic adhesive strength and shear stress has a thermal shock, low temperature, high temperature, high temperature and high humidity reliability (temperature 60 ℃, humidity 90% accelerated life evaluation, temperature 85 ℃, humidity 85% accelerated life evaluation) at least 4 kgf / inch retention could be obtained. Since the composition with a higher coefficient of thermal expansion (CTE) increases with temperature change, long-term reliability seems to be inferior.

Although non-limiting and exemplary implementations of the present invention have been described above, the technical idea of the present invention is not limited to the accompanying drawings or the above description. It is obvious to those skilled in the art that various types of modifications are possible within the scope of the technical spirit of the present invention, and also, these types of modifications will fall within the scope of the claims of the present invention.

Claims (17)

As an adhesive film for encapsulating organic electronic devices,
It includes a buffer adhesive layer located on the organic electronic device side,
The buffer adhesive layer has an organic electronic device sealing adhesive film, characterized in that the 25 ℃ value of Tan (delta) divided by the loss modulus (Loss Modulus) by the storage modulus (Storage Modulus) of the buffer adhesive layer is 1.2 or more and less than 1.8.
According to claim 1,
An adhesive film for encapsulating an organic electronic device, characterized in that the temperature when the Tan (delta) obtained by dividing the Loss Modulus by the Storage Modulus of the buffer adhesive layer is the maximum value is 20 ° C to 27 ° C.
According to claim 1,
An adhesive film for encapsulating an organic electronic device, characterized in that the viscosity of the buffer adhesive layer at 25 ° C is 11 to 300,000 Pa S.
According to claim 1,
The adhesive film is an adhesive film for sealing an organic electronic device, characterized in that the 25 ℃ viscosity of the entire adhesive layer including the buffer adhesive layer and the moisture absorption adhesive layer is 15 ~ 550,000 Pa · S.
According to claim 1,
The adhesive film is an adhesive film for encapsulating an organic electronic device, characterized in that the coefficient of thermal expansion (CTE) value is 1000ppm or less.
According to claim 1,
The adhesive film is an adhesive film for sealing an organic electronic device, characterized in that the shear stress value measured at room temperature at a speed of 300mm / min is 3kgf / φ6mm or more.
According to claim 1,
The adhesive film is an adhesive film for encapsulating an organic electronic device, characterized in that the basic adhesive strength value measured at room temperature at a speed of 300mm / min is 6kgf / inch or more.
According to claim 1,
The adhesive film is for organic electronic device encapsulation, characterized in that the adhesive strength after a thermal shock test of 100 cycles in which the temperature is raised and maintained at 60 ° C for 30 minutes after maintaining at -20 ° C for 30 minutes is at least 66.7% of the basic adhesive strength or at least 4 kgf / inch. adhesive film.
According to claim 1,
The adhesive film is an adhesive film for encapsulating an organic electronic device, characterized in that the adhesive strength after a low temperature storage test left at -20 ° C for 1,000 hours is 66.7% or more of the basic adhesive strength or 4 kgf / inch or more.
According to claim 1,
The adhesive film is an organic electronic device sealing adhesive film, characterized in that the adhesive strength after a high temperature storage test left at 60 ℃ for 1,000 hours is 66.7% or more of the basic adhesive strength or 4 kgf / inch or more.
According to claim 1,
The adhesive film has an adhesive strength of 66.7% or more of the basic adhesive strength or 4 kgf / inch or more of the basic adhesive strength after a high-temperature, high-humidity test left at a temperature of 85 ° C. and a humidity of 85% for 400 hours. Adhesive film for encapsulation.
According to claim 1,
The adhesive film has an adhesive strength of 66.7% or more of the basic adhesive strength or 4 kgf / inch or more of the basic adhesive strength after a high-temperature, high-humidity test in which the adhesive film is left at a temperature of 60 ° C. and a humidity of 90% for 336 hours. Adhesive film for sealing.
According to claim 1,
The adhesive film is composed of an adhesive layer including a buffer adhesive layer and a moisture absorption adhesive layer,
The buffer adhesive layer uses a mixture of polyisobutylene and butyl rubber as a binder resin,
An adhesive film for sealing an organic electronic device, characterized in that the moisture absorption adhesive layer uses only polyisobutylene as a binder resin.
According to claim 1,
The adhesive film for encapsulating an organic electronic device, characterized in that the adhesive layer contains two or more types of DCPD-based tackifiers having different softening points.
An organic electronic device encapsulant comprising the adhesive film for encapsulating an organic electronic device according to any one of claims 1 to 14.
A method of encapsulating an organic electronic device, wherein the organic electronic device is encapsulated with the organic electronic device encapsulant of claim 15.
An organic electronic device characterized in that it is sealed with the organic electronic device encapsulant of claim 15.

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