Adhesive composition

Abstract

Provided are an adhesive composition and an organic electronic device (OED) including the same, and more 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, and facilitates coating in the process of forming the encapsulation structure of the OED, thereby preventing the problem of flow of bubbles into the encapsulation structure or blocking of a coating nozzle and thus enhancing processability, and an OED including the same.

Claims

1. An adhesive composition for encapsulating an organic electronic element, comprising: an olefin-based resin having at least one reactive functional group, a curable resin; a reactive diluent of Chemical Formula 1, ##STR00002## where R.sub.1 is hydrogen or an alkyl group having 1 to 4 carbon atoms, n is an integer of 2 or higher, and X is a residue derived from a linear, branched or cyclic alkyl or alkenyl group having 3 to 30 carbon atoms, wherein a thixotropic index (T) according to General Equation 1 is in the range of 1.35 to 5,
T=V.sub.0.5/V.sub.5  [General Equation 1] where V.sub.0.5 is a viscosity of the adhesive composition measured using a Brookfield viscometer with an RV-7 spindle at a temperature of 25° C. and a rotational speed of 0.5 rpm, and V.sub.5 is a viscosity of the adhesive composition measured using a Brookfield viscometer with an RV-7 spindle at a temperature of 25° C. and a rotational speed of 5 rpm, wherein the olefin-based resin includes an isobutylene-based homopolymer or copolymer, and wherein the adhesive composition comprises the olefin-based resin, the curable resin and the reactive diluent in an amount of 60 to 70 parts by weight, 20 to 30 parts by weight and 10 parts by weight, respectively, and wherein the viscosity V.sub.0.5 is in the range of 100,000 to 1,000,000 cPs.

2. The adhesive composition of claim 1, further comprising: an inorganic filler.

3. The adhesive composition of claim 2, wherein the inorganic filler has a BET specific surface area in the range of 35 to 500 m.sup.2/g.

4. The adhesive composition of claim 2, wherein the inorganic filler is comprised at 0.1 to 20 parts by weight with respect to 100 parts by weight of the olefin-based resin.

5. The adhesive composition of claim 1, wherein the olefin-based-resin has a weight average molecular weight of 100,000 or less.

6. The adhesive composition of claim 1, wherein the at least one reactive functional group 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.

7. The adhesive composition of claim 1, wherein the curable resin comprises one or more curable functional groups.

8. The adhesive composition of claim 1, further comprising: an initiator or a curing agent.

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

10. The adhesive composition of claim 9, wherein the moisture absorbent is comprised at 5 to 100 parts by weight with respect to 100 parts by weight of the olefin-based resin.

11. 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 including the adhesive composition of claim 1.

12. The organic electronic device of claim 11, 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.

13. 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.

14. The adhesive composition of claim 1, wherein the viscosity V.sub.0.5 is in the range of 100,000 to 460,000 cPs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The FIGURE 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) As main components, an olefin-based resin, that is, an acid anhydride-modified polyisobutylene resin (BASF, Mn 1000 g/mol, Glissopal SA), curable resins, that is, an alicyclic epoxy resin (Tohto Kasei, ST-3000, epoxy equivalent weight: 230 g/eq, viscosity: 3000 cPs) and an epoxy acrylate (Sartomer, CN110), and reactive diluents, that is, a polybutadiene dimethacrylate (Sartomer, CN301) and 1,6-hexanediol diacrylate (HDDA) were put into a mixing vessel in a weight ratio of 70:10:10:6:4 (GlissopalSA:ST-3000:CN110:CN301:HDDA) at room temperature. As a radical initiator, 5 parts by weight of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure 651, Ciba) was put into the vessel with respect to 100 parts by weight of the main components, and as a heat-curing agent, 10 parts by weight of an imidazole-based curing agent (Shikoku, 2P4MZ) was put into the vessel with respect to 100 parts by weight of the main components. Also, 1 part by weight of fumed silica (Aerosil, Evonik, R805, particle size: 10˜20 nm, BET=150 m.sup.2/g) as an inorganic filler was put into the vessel with respect to 100 parts by weight of the main components. Meanwhile, 10 parts by weight of calcium oxide (CaO, Aldrich) as a moisture absorbent was further put into the vessel with respect to 100 parts by weight of the main components.

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

Example 2

(11) As main components, an olefin-based resin, that is, an acid anhydride-modified polyisobutylene resin (BASF, Mn 1000 g/mol, Glissopal SA), curable resins, that is, an alicyclic epoxy resin (Daicel, Celloxide 2021P, epoxy equivalent weight: 130 g/eq, viscosity: 250 cPs) and an epoxy acrylate (Sartomer, CN110), and reactive diluents, that is, a polybutadiene dimethacrylate (Sartomer, CN301) and 1,6-hexanediol diacrylate (HDDA) were put into a mixing vessel in a weight ratio of 70:10:10:6:4 (GlissopalSA:2021P:CN110:CN301:HDDA) at room temperature. As a radical initiator, 5 parts by weight of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure 651, Ciba) was put into the vessel with respect to 100 parts by weight of the main components, and 10 parts by weight of a photocationic initiator (Sa-apro, CPI-101A) 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: 10.Math.20 nm, BET=150 m.sup.2/g) was put into the vessel with respect to 100 parts by weight of the main components. Meanwhile, as a moisture absorbent, 10 parts by weight of calcium oxide (CaO, Aldrich) was further put into the vessel with respect to 100 parts by weight of the main components.

(12) A homogeneous composition solution was prepared by agitating the mixing vessel using a planetary mixing device (Kurabo Industries, KK-250s).

Example 3

(13) As main components, an olefin-based resin, that is, an acid anhydride-modified polyisobutylene resin (Glissopal SA), curable resins, that is, a urethane acrylate (Sartomer, CN9013) and an epoxy acrylate (Sartomer, CN110), and reactive diluents, that is, a polybutadiene dimethacrylate (Sartomer, CN301) and 1,6-hexanediol diacrylate (HDDA) were put into a mixing vessel in a weight ratio of 60:15:15:5:5 (Glissopal SA:CN9013:CN110:CN301:HDDA) at room temperature. As a radical initiator, 5 parts by weight of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure 651, Ciba) was put into the vessel with respect to 100 parts by weight of the main components. Also, as an inorganic filler, 7 parts by weight of fumed silica (Aerosil, Evonik, R805, particle size: 10˜20 nm, BET=150 m.sup.2/g) was put into the vessel with respect to 100 parts by weight of the main components. Meanwhile, as a moisture absorbent, 10 parts by weight of calcium oxide (CaO, Aldrich) was further put into the vessel with respect to 100 parts by weight of the main components.

(14) A homogeneous composition solution was prepared by agitating the mixing vessel using a planetary mixing device (Kurabo Industries, KK-250s).

Comparative Example 1

(15) An adhesive composition was prepared by the same method as described in Example 1, except that a polyisobutylene resin (BASF, B14) was used as an olefin-based resin.

Comparative Example 2

(16) An adhesive composition was prepared by the same method as described in Example 1, except that an olefin-based resin, that is, an acid anhydride-modified polyisobutylene resin (Glissopal SA), curable resins, that is, an alicyclic epoxy resin (Tohto Kasei, ST-3000) and an epoxy acrylate (Sartomer, CN110), and reactive diluents, that is, a polybutadiene dimethacrylate (Sartomer, CN301) and 1,6-hexanediol diacrylate (HDDA) as main components were put into a mixing vessel in a weight ratio of 30:30:30:6:4 (GlissopalSA:ST-3000:CN110:CN301:HDDA), and 3 parts by weight of an inorganic filler was put into the vessel with respect to 100 parts by weight of the main components.

Comparative Example 3

(17) An adhesive composition was prepared by the same method as described in Example 1, except that fumed silica (Aerosil, Evonik, RY 50, BET=30 m.sup.2/g) as an inorganic filler was put into the vessel.

Comparative Example 4

(18) An adhesive composition was prepared by the same method as described in Example 3, except that an olefin-based resin, that is, an acid anhydride-modified polyisobutylene resin (Glissopal SA), curable resins, that is, a urethane acrylate (Sartomer, CN9013) and an epoxy acrylate (Sartomer, CN110), and reactive diluents, that is, a polybutadiene dimethacrylate (Sartomer, CN301) and 1,6-hexanediol diacrylate (HDDA) as main components were put into a mixing vessel in a weight ratio of 60:10:10:5:15 (GlissopalSA:CN9013:CN110:CN301:HDDA), and 3 parts by weight of an inorganic filler was put into the vessel with respect to 100 parts by weight of the main components.

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

(20) 1. Measurement of Viscosity and Thixotropic Index

(21) Viscosities of the adhesive compositions prepared in the examples and comparative examples were measured using a Brookfield viscometer, RVDV−II+Pro, as follows:

(22) The measurement was conducted on the prepared adhesive composition at a temperature of 25° C. and a rotational speed of 0.5 rpm. Specifically, viscosity V.sub.0.5 was measured with respect to a torque at an RV-7 spindle of the Brookfield viscometer. Also, viscosity V.sub.5 was measured with respect to a torque at an RV-7 spindle of the Brookfield viscometer under conditions of a temperature of 25° C. and a rotational speed of 5 rpm.

(23) From the viscosity measured as described above, a thixotropic index (TI) was calculated according to General Equation 1.
T=V.sub.0.5/V.sub.5  [General Equation 1]

(24) 2. Coating Property

(25) A coating property was examined by applying the adhesive composition solution prepared in each of the examples and the comparative examples to side surfaces of a 0.7T soda lime glass in a tetragonal shape having a size of 150 mm×150 mm using a Musashi 200DS apparatus (needle number: #18, dispensing speed: 10/mm/sec). When there were no bubbling and blocking of a nozzle of the apparatus in coating, it was denoted as O, when bubbles were generated during coating or the composition was widely diffused, thereby losing the original shape after coating, it was denoted as Δ, and when a large amount of bubbles during coating or coating was ceased by blocking a nozzle, it was denoted as X.

(26) 3. Precipitation Stability

(27) Precipitation stabilities of the adhesive compositions of the examples and the comparative examples were evaluated as follows. The prepared adhesive composition was mixed and defoamed, injected into a syringe, and left at 25° C. for 3 days. Afterward, the coating was performed to evaluate if the inorganic filler was precipitated in a lower portion of the syringe. When an upper layer and a lower layer were coated with the same amount of the inorganic filler and there was no blocking of a nozzle, it was denoted as O, and when a nozzle was blocked during coating and the upper layer is more transparent than the lower layer, it was denoted as X.

(28) 4. Thermal Resistance and Moisture Resistance

(29) The adhesive composition solution prepared in each of the examples and the comparative examples was applied to side surfaces of a 0.7T soda lime glass in a tetragonal shape having a size of 150 mm×150 mm using a Musashi 200DS apparatus. Afterward, the coated glass was laminated with the same type of a glass, thereby preparing a sample. The adhesive composition was irradiated with light (a metal halide lamp) in the UV-A wavelength range at a dose of 3 J/cm.sup.2, and heated in an oven at 100° C. for 3 hours (in Examples 2 and 3 and Comparative Example 4, irradiated with light at a dose of 5 J/cm.sup.2). Then, the sample was maintained in a constant temperature and humidity chamber at 85° C. and relative humidity of 85% for about 1000 hours.

(30) In the measurement of thermal resistance, when there were no change in a coated region and on the side surfaces of the coated region, it was denoted as O, and when there was an empty space in the coated region, it was denoted as X.

(31) In the measurement of moisture resistance, when there was no lifting in a moisture-permeated part, it was denoted as O, and when the moisture-permeated part was lifted from the glass, it was denoted as X.

(32) 5. Compatibility

(33) Compatibility was evaluated with respect to the adhesive compositions of the examples and the comparative examples. Phase separation was examined after the prepared adhesive composition was left in a vessel at 25° C. for 3 days. When phase separation did not occur in the composition, it was denoted as O, when partial phase separation occurred, it was denoted as A, and when phase separation occurred into two layers, it was denoted as X.

(34) TABLE-US-00001 TABLE 1 Thermal Viscosity Precip- resistance/ Thixotropic (0.5 rpm) Coating itation water Compati- index (TI) cPs property stability resistance bility Example 1 1.6 280,000 ◯ ◯ ◯/◯ ◯ Example 2 1.4 120,000 ◯ ◯ ◯/◯ ◯ Example 3 3.1 450,000 ◯ ◯ ◯/◯ ◯ Comparative 1.1 470,000 X ◯ X/X X Example 1 Comparative 1.3 220,000 ◯ ◯ ◯/X Δ Example 2 Comparative 1.1 170,000 X ◯ ◯/◯ ◯ Example 3 Comparative 1.3 89,000 Δ X X/◯ ◯ Example 4