News Column

Patent Issued for Adhesive Film and Method of Encapsulating Organic Electrode Device Using the Same

June 18, 2014

By a News Reporter-Staff News Editor at Journal of Engineering -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Yoo, Hyun Jee (Daejeon, KR); Cho, Yoon Gyung (Daejeon, KR); Shim, Jung Sup (Daejeon, KR); Lee, Suk Chin (Daejeon, KR); Jeong, Kwang Jin (Chungbuk, KR); Chang, Suk Ky (Daejeon, KR), filed on May 2, 2013, was published online on June 3, 2014.

The patent's assignee for patent number 8742411 is LG Chem, Ltd. (Seoul, KR).

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates to an adhesive film and a method of encapsulating an organic electronic device (OED) using the same.

"An organic electronic device (OED) refers to a device including an organic material layer that generates an alternating current with electric charges through the combination of holes and electrons, and examples of the OED may include a photovoltaic device, a rectifier, a transmitter and an organic light emitting diode (OLED).

"Among the OEDs, the OLED has low power consumption and rapid response time and is desirable in manufacturing a thin display or lighting device, compared to a conventional light source. Also, the OLED is expected to be applied to various fields such as a variety of portable devices, monitors, notebook computers and televisions due to its excellent space accessibility.

"Durability is one of the most important problems to be solved in order to commercialize an OLED and expand its use. An organic material and metal electrode included in the OLED are easily oxidized by external factors such as moisture. Thus, a product including the OLED is highly sensitive to environmental factors. Accordingly, a variety of methods have been proposed to effectively prevent oxygen or moisture from penetrating into an OED such as an OLED from the external environments.

"A method of processing a metal can or a glass into a cap shape having a groove and loading the groove with a powdery dehumidifying agent to absorb moisture or manufacturing a metal can or a glass in the form of a film and sealing the film using a double-sided adhesive tape has been used in the art.

"Japanese Patent Laid-Open Publication No. Hei9-148066 discloses an organic EL element including a stacked body having a structure in which an organic light emitting layer made of an organic compound is arranged between a pair of facing electrodes, an airtight container configured to protect the stacked body from the air, and a drying unit such as an alkaline metal oxide or an alkaline earth metal oxide arranged in the airtight container. However, such an organic EL element has problems in that the entire thickness of a display device is increased due to a shape of the airtight container, it is vulnerable to physical impacts due to the presence of the internal space, and its heat radiation property is poor when it is manufactured on a large scale.

"U.S. Pat. No. 6,226,890 discloses a method of desiccating an electronic device including a desiccant layer formed using a desiccant and a binder, wherein the desiccant includes solid particle having a particle size of 0.1 to 200 .mu.m. However, the desiccant layer has insufficient moisture absorption capacity. When a curable resin in a cured state does not meet a water vapor transmission rate (WVTR) of 50 g/m.sup.2day or less due to the characteristics of the binder surrounding a moisture absorbent, the curable resin does not exert sufficient performance because its moisture apposition rate actually increases during an acceleration test.

"In order to solve these problems, Korean Patent Publication No. 2007-0072400 discloses an organic EL element. When an epoxy sealant includes a moisture absorbent, the epoxy sealant serves to chemically absorb moisture passed into the organic EL element and slow moisture penetration into the organic EL element. However, physical damage may be caused to the organic EL element due to volume expansion caused by reaction of the moisture absorbent with moisture. Also, when a metal oxide is used as the moisture absorbent, the metal oxide may react with moisture to generate a strongly basic substance, which causes chemical damage to a passivation layer and a cathode layer.

"Therefore, there is a demand for development of an encapsulation material capable of effectively preventing penetration of moisture and also reducing damage to an OED."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "The present invention is directed to providing an adhesive film, and a product and method of encapsulating an organic electronic device (OED) using the same.

"One aspect of the present invention provides an adhesive film for encapsulating an OED. Here, the adhesive film includes a curable hot-melt adhesive layer including a curable resin and moisture absorbent, the curable hot-melt adhesive layer includes a first region coming in contact with the OED upon encapsulation of the OED, and a second region not coming in contact with the OED, and the moisture absorbent is present at contents of 0 to 20% and 80 to 100% in the first and second regions, respectively, based on the total weight of the moisture absorbent in the adhesive layer.

"Another aspect of the present invention provides a product for encapsulating an OED including a substrate, an OED formed on the substrate and an adhesive film for encapsulating the OED. Here, a first region of an adhesive layer of the adhesive film covers the OED.

"Still another aspect of the present invention provides a method of encapsulating an OED. Here, the method includes applying the adhesive film to a substrate having the OED formed therein so that a first region of an adhesive layer of the adhesive film can cover the OED and curing the adhesive layer."

For additional information on this patent, see: Yoo, Hyun Jee; Cho, Yoon Gyung; Shim, Jung Sup; Lee, Suk Chin; Jeong, Kwang Jin; Chang, Suk Ky. Adhesive Film and Method of Encapsulating Organic Electrode Device Using the Same. U.S. Patent Number 8742411, filed May 2, 2013, and published online on June 3, 2014. Patent URL:

Keywords for this news article include: LG Chem Ltd., Nanotechnology, Organic Electronic, Emerging Technologies.

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Source: Journal of Engineering

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