Adhesive composition

Abstract

Provided are an adhesive composition and an organic electronic device (OED) including the same, and particularly, an adhesive composition, which may form an encapsulation structure effectively blocking moisture or oxygen flowing into an OED from the outside, thereby ensuring the lifespan of the OED, realize a top-emission OED, and exhibit excellent adhesive durability and reliability, and an OED including the same.

Claims

1. An adhesive composition for encapsulating an organic electronic element, comprising: an olefin-based resin having a water vapor transmission rate (WVTR) of 50 g/m.sup.2.Math.day or less; a heat-curable resin; and a photocurable compound, wherein the olefin-based resin has a weight average molecular weight of less than 100,000, wherein the olefin-based resin, the heat-curable resin and the photocurable compound are comprises at 40 to 90 parts by weight, 5 to 50 parts by weight and 1 to 40 parts by weight, respectively, and wherein the adhesive composition is a solventless liquid at 25 C.

2. The adhesive composition of claim 1, wherein the olefin-based resin has one or more reactive functional groups having reactivity with the heat-curable resin.

3. The adhesive composition of claim 2, wherein the functional group having reactivity with the heat-curable resin is an acid anhydride group, a carboxyl group, an epoxy group, an amino group, a hydroxyl group, an isocyanate group, an oxazoline group, an oxetane group, a cyanate group, a phenol group, a hydrazide group or an amide group.

4. The adhesive composition of claim 1, wherein heat-curable resin comprises at least one heat-curable functional group.

5. The adhesive composition of claim 4, wherein the heat-curable functional group comprises an epoxy group, an isocyanate group, a hydroxyl group, a carboxyl group or an amide group.

6. The adhesive composition of claim 1, wherein the heat-curable resin is comprised at 10 to 70 parts by weight with respect to 100 parts by weight of the olefin-based resin.

7. The adhesive composition of claim 1, further comprising: a heat-curing agent.

8. The adhesive composition of claim 7, wherein the heat-curing agent is a latent curing agent.

9. The adhesive composition of claim 8, wherein the heat-curing agent is comprised at 1 to 30 parts by weight with respect to 100 parts by weight of the heat-curable resin.

10. The adhesive composition of claim 1, wherein the photocurable compound is a multifunctional active energy ray-polymerizable compound.

11. The adhesive composition of claim 1, wherein the photocurable compound is comprised at 10 to 100 parts by weight with respect to 100 parts by weight of the olefin-based resin.

12. The adhesive composition of claim 1, further comprising: a photoradical initiator at 0.1 to 20 parts by weight with respect to 100 parts by weight of the photocurable compound.

13. The adhesive composition of claim 1, further comprising: a moisture absorbent.

14. The adhesive composition of claim 13, wherein the moisture absorbent is included at 5 to 100 parts by weight with respect to 100 parts by weight of the olefin-based resin.

15. An organic electronic device, comprising: a substrate; an organic electronic element formed on the substrate; and a side encapsulation layer formed on a peripheral portion of the substrate to surround side surfaces of the organic electronic element, and comprising the adhesive composition of claim 1.

16. The organic electronic device of claim 15, further comprising: an entire encapsulation layer for covering the entire surface of the organic electronic element, wherein the entire encapsulation layer is present in the same plane as the side encapsulation layer.

17. A method of manufacturing an organic electronic device, comprising: applying the adhesive composition of claim 1 to a peripheral portion of a substrate on which an organic electronic element is formed to surround side surfaces of the organic electronic element; irradiating the adhesive composition with light; and heating the adhesive composition.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a cross-sectional view of an OED according to an exemplary embodiment of the present application.

EXPLANATION OF REFERENCE NUMERALS

(2) 1: adhesive

(3) 10: side encapsulation layer

(4) 11: entire encapsulation layer

(5) 21: substrate

(6) 22: cover substrate

(7) 23: organic electronic element

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

(8) Hereinafter, the present application will be described in further detail with reference to examples according to the present application and comparative examples not according to the present application, and the scope of the present application is not limited to the following examples.

EXAMPLE 1

(9) A polyisobutylene resin (DAELIM, PB2400, Mn=2,400 g/mol, Mw=4,300 g/mol) as an olefin-based resin, an alicyclic epoxy resin (Mitsubishi Chemical, YX8000, epoxy equivalent weight: 205 g/eq, viscosity: 18500 cPs) as a heat-curable resin and trimethylol propane triacrylate (Sartomer, SR351) as a photocurable compound were put into a mixing vessel in a weight ratio of 60:30:10 (PB2400:YX8000:SR351) at room temperature. As a radical initiator, 1 part by weight of bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (Irgacure 819, BASF) was put into the vessel with respect to 100 parts by weight of the main components (the olefin-based resin, the heat-curable resin and the photocurable compound), as a heat-curing agent, 5 parts by weight of an imidazole-based curing agent (2P4MZ, 2-phenyl-4-methylimidazole, Shikoku) was put into vessel with respect to 100 parts by weight of the main components, and 1 part by weight of an epoxy silane (glycidyloxypropyl trimethoxysilane, KBM403, Shinetsu) was put into the vessel with respect to 100 parts by weight of the main components. Also, as an inorganic filler, 3 parts by weight of fumed silica (Aerosil, Evonik, R805, particle size: about 1020 nm) was put into the vessel with respect to 100 parts by weight of the main components. Meanwhile, as a moisture absorbent, 20 parts by weight of calcium oxide (CaO, Aldrich, particle size: 15 m) was further put into the vessel with respect to 100 parts by weight of the main components.

(10) A homogeneous composition solution was prepared in the mixing vessel using a planetary mixer (Kurabo Industries, KK-250s).

EXAMPLE 2

(11) An adhesive composition was prepared by the same method as described in Example 1, except that an acid anhydride-modified polyisobutylene (BASF, Glissopal SA, Mn 1000 g/mol, Mw=970 g/mol) was used as an olefin-based resin, the olefin-based resin, a heat-curable resin and a photocurable compound were put into a mixing vessel in a weight ratio of 70:20:10, and 25 parts by weight of a moisture absorbent and 2 parts by weight of an inorganic filler were put into the mixing vessel.

EXAMPLE 3

(12) An adhesive composition was prepared by the same method as described in Example 2, except that 30 parts by weight of a moisture absorbent was put into a mixing vessel.

EXAMPLE 4

(13) An adhesive composition was prepared by the same method as described in Example 1, except that an acid anhydride-modified polyisobutylene (BASF, Glissopal SA, Mn 1000 g/mol) as an olefin-based resin, an aromatic epoxy resin (DIC, Epiclon 850, epoxy equivalent weight: 184 g/eq, viscosity: 11000 cPs) as a heat-curable resin and trimethylol propane triacrylate (Sartomer, SR351) as a photocurable compound were put into a mixing vessel in a weight ratio of 60:30:10 (PB2400:Epiclon 850:SR351).

COMPARATIVE EXAMPLE 1

(14) An alicyclic epoxy resin (Mitsubishi Chemical, YX8000, epoxy equivalent weight: 205 g/eq, viscosity: 18500 cPs) and an aromatic epoxy resin (DIC, Epiclon 850, epoxy equivalent weight: 184 g/eq, viscosity: 11000 cPs) were put into a mixing vessel in a weight ratio of 50:50 (YX8000:Epiclon850) at room temperature. 5 parts by weight of an imidazole-based curing agent (2P4MZ, 2-phenyl-4-methylimidazole, Shikoku) as a heat-curing agent was put into the vessel with respect to 100 parts by weight of the main components (the alicyclic epoxy resin and the aromatic epoxy resin), and 1 part by weight of an epoxy silane (glycidyloxypropyl trimethoxysilane, KBM403, Shinetsu) was put into the vessel with respect to 100 parts by weight of the main components. Also, 3 parts by weight of fumed silica (Aerosil, Evonik, R805, particle size: 1020 nm) as an inorganic filler was put into the vessel with respect to 100 parts by weight of the main components. Meanwhile, 20 parts by weight of calcium oxide (CaO, Aldrich, particle size: 15 m) as a moisture absorbent was further put into the vessel with respect to 100 parts by weight of the main components.

(15) A homogeneous composition solution was prepared in the mixing vessel using a planetary mixer (Kurabo Industries, KK-250s).

COMPARATIVE EXAMPLE 2

(16) An adhesive composition was prepared by the same method as described in Comparative Example 1, except that a polyisobutylene resin (DAELIM PB2400, Mn=2,400 g/mol) as an olefin-based resin, instead of an aromatic epoxy resin, and an alicyclic epoxy resin (Mitsubishi Chemical, YX8000, epoxy equivalent weight: 205 g/eq, viscosity: 18500 cPs) as a heat-curable resin were put into a mixing vessel in a weight ratio of 70:30 (PB2400:YX8000).

COMPARATIVE EXAMPLE 3

(17) A polyisobutylene resin (DAELIM PB2400, Mn=2,400 g/mol) as an olefin-based resin and trimethylol propane triacrylate (Sartomer, SR351) as a photocurable compound were put into a mixing vessel in a weight ratio of 70:30 (PB2400:SR351) at room temperature. As a radical initiator, 1 part by weight of bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (Irgacure 819, BASF) was put into the vessel with respect to 100 parts by weight of the main components (the olefin-based rein and the photocurable compound), and 1 part by weight of an epoxy silane (glycidyloxypropyl trimethoxysilane, KBM403, Shinetsu) was put into the vessel with respect to 100 parts by weight of the main components. Also, as an inorganic filler, 3 parts by weight of fumed silica (Aerosil, Evonik, R805, particle size 1020 nm) was put into the vessel with respect to 100 parts by weight of the main components. Meanwhile, as a moisture absorbent, 20 parts by weight of calcium oxide (CaO, Aldrich, particle size: 15 m) was further put into the vessel with respect to 100 parts by weight of the main components.

(18) A homogeneous composition solution was prepared in the mixing vessel using a planetary mixer (Kurabo Industries, KK-250s).

(19) Hereinafter, physical properties in the examples and comparative examples were evaluated by the following methods.

(20) 1. Adhesive Durability and Reliability at High Temperature and High Humidity

(21) The adhesive composition prepared in each one of the examples and the comparative examples was injected into a syringe, defoamed, applied to a peripheral portion (edge) of a glass substrate, and laminated with a cover substrate. Subsequently, the coated adhesive composition was irradiated with light in the UV-A wavelength range at a dose of 5 J/cm.sup.2 and heated at 100 C. for 3 hours, resulting in preparing a specimen. Afterward, the specimen was maintained in a constant temperature and humidity chamber at 85 C. and 85% for about 100 hours, and observed whether or not to have lifting, bubbles or haze at an interface between the glass substrate and the adhesive. With the naked eye, when at least one lifting, bubbles or haze was observed at the interface between the glass substrate and the adhesive, it was denoted as X, when lifting, bubbles or haze was partially observed, it was denoted as A, and when there was no lifting, bubbles or haze, it was denoted as O.

(22) 2. Evaluation of Accelerating Lifespan of Element

(23) A calcium test was performed to indirectly evaluate the lifespan of an OELD to which one of the adhesive compositions in the examples and the comparative examples under accelerating conditions. In detail, seven spots of calcium (Ca) each having a size of 5 mm5 mm and to a thickness of 100 nm were deposited on a glass substrate having a size of 100 mm100 mm, the adhesive composition prepared in the example or the exemplary embodiment was applied to coat a peripheral portion (edge) of the substrate 3 mm apart from the calcium-deposited portion using a dispenser, and each of the calcium-deposited portions on the substrate was laminated with a cover glass and pressed so that the adhesive composition had a thickness of 3 mm, and then irradiated with light in the UV-A wavelength range at a dose of 5 J/cm.sup.2. Afterward, the substrate was cured in a high temperature dryer at 100 C. for 3 hours, and the encapsulated calcium (Ca) specimen was cut into pieces in a size of 14 mm14 mm. The obtained specimens were maintained in a constant temperature and humidity chamber in an environment of 85 C. and 85% R.H. for 1000 hours. Here, when the calcium-deposited portion was a little eroded by an oxidation reaction caused by moisture permeation, it was denoted as X, some of the calcium-deposited portions were eroded, it was denoted as , and when there was no change in the calcium-deposited portions, it was denoted as O.

(24) TABLE-US-00001 TABLE 1 High temperature high Evaluation of humidity adhesive accelerating durability and reliability lifespan of element Example1 Example2 Example3 Example4 Comparative X X Example1 Comparative X Example2 Comparative X X Example3