Adhesive composition

Abstract

Disclosed is related to an adhesive composition for encapsulating an organic electronic element and an organic electronic device comprising the same. The adhesive composition includes a curable compound having no carbon-carbon unsaturated group, a thermal initiator, and a photo-initiator. The adhesive composition can form a structure capable of effectively blocking moisture or oxygen introduced from the outside into the organic electronic device, thereby securing the lifetime of the organic electronic device, can realize a top emitting organic electronic device, and can prevent defects such as dark spots which may occur in the organic electronic device.

Claims

1. An adhesive composition for encapsulating an organic electronic element comprising: a first curable compound and either a second curable compound or a third curable compound, each curable compound having no carbon-carbon unsaturated group, a thermal initiator, and a photo-initiator, wherein the adhesive composition is in a liquid form at room temperature, wherein the adhesive composition has a Shore hardness (Shore A) of 20 to 60 as measured according to the standard of JIS K 6253 after pre-curing, wherein the thermal initiator is comprised in an amount of 0.01 to 0.45 parts by weight relative to 100 parts by weight of the curable compounds, wherein the photo-initiator is comprised in an amount of 0.01 to 0.45 parts by weight relative to 100 parts by weight of the curable compounds, wherein the first curable compound comprises a compound having a cyclic structure in its molecular structure, and wherein the second curable compound comprises a linear or branched aliphatic compound, and when present is provided in an amount of 5 to 60 parts by weight relative to 100 parts by weight of the first curable compound; and wherein the third curable compound comprises a compound containing at least one or more oxetane groups, and when present is provided in an amount of 5 to 60 parts by weight relative to 100 parts by weight of the first curable compound.

2. The adhesive composition for encapsulating an organic electronic element according to claim 1, wherein the pre-curing comprises irradiating the composition with ultraviolet of any one light quantity of 0.1 to 10 J/cm.sup.2 at any one wavelength in a range of 300 to 450 nm and any one intensity of 5 to 200 mW/cm.sup.2.

3. The adhesive composition for encapsulating an organic electronic element according to claim 1, wherein a curing rate of the composition after pre-curing is any one curing rate in a range of 10 to 90%.

4. The adhesive composition for encapsulating an organic electronic element according to claim 1, wherein the first curable compound and the second curable compound comprise at least one or more curable functional groups.

5. The adhesive composition for encapsulating an organic electronic element according to claim 4, wherein the curable functional group is at least one selected from a glycidyl group, an isocyanate group, a hydroxy group, a carboxyl group, an amide group, an epoxide group, a cyclic ether group, a sulfide group, an acetal group and a lactone group.

6. The adhesive composition for encapsulating an organic electronic element according to claim 4, wherein each curable compound is at least bifunctional or more.

7. The adhesive composition for encapsulating an organic electronic element according to claim 1, wherein the thermal initiator or the photo-initiator is a cationic initiator.

8. The adhesive composition for encapsulating an organic electronic element according to claim 1, further comprising a curing retardant.

9. The adhesive composition for encapsulating an organic electronic element according to claim 8, wherein the curing retardant is comprised in an amount of 0.01 to 10 parts by weight relative to 100 parts by weight of the curable compounds.

10. The adhesive composition for encapsulating an organic electronic element according to claim 1, wherein a light transmittance to visible light according to JIS K7105 standard after curing is 90% or more.

11. The adhesive composition for encapsulating an organic electronic element according to claim 1, wherein a haze measured according to the standard of JIS K7105 after curing is 5% or less.

12. The adhesive composition for encapsulating an organic electronic element according to claim 1, wherein a YI (yellow index) value according to ASTM D 1003 standard after curing is in a range of 0 to 2.0.

13. An organic electronic device comprising a substrate; an organic electronic element formed on the substrate; and a top encapsulating layer encapsulating the entire surface of said organic electronic element and comprising the adhesive composition according to claim 1.

14. The organic electronic device according to claim 13, further comprising a side encapsulating layer formed on the substrate so as to surround the side of the organic electronic element, wherein said side encapsulating layer and said top encapsulating layer are present on the same plane.

15. A method for manufacturing an organic electronic device comprising steps of: applying the adhesive composition of claim 1 on a substrate, on which an organic electronic element is formed, to encapsulate the entire surface of said organic electronic element; irradiating said adhesive composition with light; and applying heat to said adhesive composition.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The drawing is a cross-sectional view showing an organic electronic device according to one example of the present invention.

EXPLANATION OF REFERENCE NUMERALS

(2) 10: side encapsulating layer 11: top encapsulating layer 21: substrate 22: cover substrate 23: organic electronic element

BEST MODE

(3) Hereinafter, the present invention will be described in more detail with reference to Examples according to the present invention and Comparative Examples not complying with the present invention, but the scope of the present invention is not limited by the following examples.

Example 1

(4) An alicyclic epoxy resin (Celloxide 2021P from Daicel) and an oxetane compound (OXT-221 from TOXOSEI) as curable compounds were introduced into a mixing vessel at a weight ratio of 70:30 (Celloxide2021P: OXT-221) at room temperature. 0.10 parts by weight of a photo-cationic initiator (BASF, Irgacure 290) and 0.03 parts by weight of a thermal cationic initiator (CXC-1612), relative to 100 parts by weight of the curable compounds, were introduced into the vessel.

(5) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Example 2

(6) An alicyclic epoxy resin (Celloxide 2021P from Daicel) and neopentyl glycol diglycidyl ether (TCI, NGDE) as curable compounds were introduced into a mixing vessel at a weight ratio of 75:25 (Celloxide 2021P: NGDE) at room temperature. 0.20 parts by weight of a photo-cationic initiator (BASF, Irgacure 290) and 0.12 parts by weight of a thermal cationic initiator (CXC-1612), relative to 100 parts by weight of the curable compounds, were introduced into the vessel. Furthermore, 0.1 parts by weight of a curing retardant (18-crown-6-ether), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(7) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Example 3

(8) An adhesive composition was prepared in the same manner as in Example 1, except that an alicyclic epoxy resin (Celloxide 2021P from Daicel) and an oxetane compound (OXT-221 from TOAGOSEI Co., Ltd.) as curing compounds were introduced into a mixing vessel at a weight ratio of 75:25 (Celloxide 2021P: OXT-221) at room temperature and 0.05 parts by weight of a photo-cationic initiator (BASF, Irgacure 290) and 0.10 parts by weight of a thermal cationic initiator (CXC-1612) were introduced into the vessel.

Example 4

(9) An alicyclic epoxy resin (Celloxide 2021P from Daicel) and neopentyl glycol diglycidyl ether (TCI, NGDE) as curable compounds were introduced into a mixing vessel at a weight ratio of 80:20 (Celloxide 2021P: NGDE) at room temperature. 0.10 parts by weight of a photo-cationic initiator (BASF, Irgacure 290) and 0.15 parts by weight of a thermal cationic initiator (CXC-1821), relative to 100 parts by weight of the curable compounds, were introduced into the vessel. Furthermore, 0.1 parts by weight of a curing retardant (18-crown-6-ether), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(10) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Example 5

(11) Alicyclic epoxy resins Celloxide 2021P (Daicel) and Celloxide 8000 (Daicel) as curable compounds were introduced into a mixing vessel at a weight ratio of 70:30 (Celloxide 2021P: Celloxide 8000) at room temperature. 0.05 parts by weight of a photo-cationic initiator (BASF, Irgacure 290) and 1.0 part by weight of a thermal cationic initiator (CXC-1821), relative to 100 parts by weight of the curable compounds, were introduced into the vessel. Furthermore, 0.12 parts by weight of a curing retardant (18-crown-6-ether), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(12) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Comparative Example 1

(13) An alicyclic epoxy resin (Celloxide 2021P from Daicel) and an oxetane compound (OXT-221 from TOXOSEI) as curable compounds were introduced into a mixing vessel at a weight ratio of 60:40 (Celloxide2021P: OXT-221) at room temperature. 0.3 parts by weight of a thermal cationic initiator (CXC-1612), relative to 100 parts by weight of the curable compounds, was introduced into the vessel. Furthermore, 0.02 parts by weight of a curing retardant (18-crown-6-ether), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(14) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Comparative Example 2

(15) An alicyclic epoxy resin (Celloxide 2021P from Daicel) and an oxetane compound (OXT-221 from TOXOSEI) as curable compounds were introduced into a mixing vessel at a weight ratio of 80:20 (Celloxide 2021P: OXT-221) at room temperature. 0.20 parts by weight of a photo-cationic initiator (BASF, Irgacure 290), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(16) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Comparative Example 3

(17) An alicyclic epoxy resin (Celloxide 2021P from Daicel) and an oxetane compound (OXT-221 from TOXOSEI) as curable compounds were introduced into a mixing vessel at a weight ratio of 70:30 (Celloxide2021P: OXT-221) at room temperature. 1.0 part by weight of a photo-cationic initiator (BASF, Irgacure 290) and 0.05 parts by weight of a thermal cationic initiator (CXC-1612), relative to 100 parts by weight of the curable compounds, were introduced into the vessel. Furthermore, 0.02 parts by weight of a curing retardant (18-crown-6-ether), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(18) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Comparative Example 4

(19) At room temperature, alicyclic epoxy resins Celloxide 2021P (Daicel) and Celloxide 8000 (Daicel) as curable compounds were introduced into a mixing vessel at a weight ratio of 80:20 (Celloxide2021P: Celloxide 8000). 0.5 parts by weight of a photo-cationic initiator (MIDORI, DTS-200) and 0.5 parts by weight of a thermal cationic initiator (CXC-1821), relative to 100 parts by weight of the curable compounds, were introduced into the vessel.

(20) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Comparative Example 5

(21) An alicyclic epoxy resin Celloxide 2021P (Daicel) and a bisphenol A epoxy resin (Kukdo Chemical Co., Ltd., YD-128) as curable compounds were introduced into a mixing vessel at a weight ratio of 80:20 (Celloxide2021P: YD-128) at room temperature. 0.1 parts by weight of a photo-cationic initiator (BASF, Irgacure 290) and 0.15 parts by weight of a thermal cationic initiator (CXC-1821), relative to 100 parts by weight of the curable compounds, were introduced into the vessel. Furthermore, 0.10 parts by weight of a curing retardant (18-crown-6-ether), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(22) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Comparative Example 6

(23) An alicyclic epoxy resin (Celloxide 2021P from Daicel) and neopentyl glycol diglycidyl ether (TCI, NGDE) as curable compounds were introduced into a mixing vessel at a weight ratio of 50:50 (Celloxide 2021P: NGDE) at room temperature. 0.20 parts by weight of a photo-cationic initiator (BASF, Irgacure 290) and 0.12 parts by weight of a thermal cationic initiator (CXC-1612), relative to 100 parts by weight of the curable compounds, were introduced into the vessel. Furthermore, 0.10 parts by weight of a curing retardant (18-crown-6-ether), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(24) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

Comparative Example 7

(25) An alicyclic epoxy resin Celloxide 2021P (Daicel) and an oxetane compound (OXT-221 from TOAGOSEI) as curable compounds were introduced into a mixing vessel at a weight ratio of 55:45 (Celloxide2021P: OXT-221) at room temperature. 0.20 parts by weight of a photo-cationic initiator (BASF, Irgacure 290) and 0.12 parts by weight of a thermal cationic initiator (CXC-1612), relative to 100 parts by weight of the curable compounds, were introduced into the vessel. Furthermore, 0.10 parts by weight of a curing retardant (18-crown-6-ether), relative to 100 parts by weight of the curable compounds, was introduced into the vessel.

(26) In the mixing vessel, a uniform composition solution was prepared using a planetary mixer (Kurabo, KK-250s).

(27) The physical properties in Examples and Comparative Examples were evaluated in the following manner.

(28) 1. Viscosity Measurement

(29) Viscosities of the adhesive compositions prepared in Examples and Comparative Examples were measured using RVDV-II+Pro as a Brookfield viscometer (LV type) as follows.

(30) For the prepared adhesive composition, it was measured at a temperature of 25° C. and a rotation speed of 100 rpm. Specifically, the viscosity was measured according to torque at the RV-63 spindle of Brookfield viscometer. In the measurement, when the viscosity was 200 cps or less, the application proceeded easily.

(31) 2. Pot Life Measurement

(32) 40 g of each adhesive composition prepared in Examples and Comparative Examples was sealed and immersed in a glass vial bottle, and then allowed to stand in an oven at 35° C. to measure the viscosity every 24 hours and the time at which the viscosity became 1.5 times the initial viscosity was recorded. In the measurement, the case where the pot life was at least 90 hours or more was set as the stability passage standard.

(33) 3. Shore Hardness Measurement

(34) The adhesive compositions prepared in Examples and Comparative Examples were each applied to a thickness of 0.3 T, then irradiated with UV of 1 J/cm.sup.2 at a wavelength of 365 nm and an intensity of 50 mW/cm.sup.2, and after one minute, the Shore hardness (Shore A) was measured according to the standard of JIS K 6253.

(35) 4. Panel High Temperature and High Humidity Test

(36) The adhesive compositions prepared in Examples and Comparative Examples were each applied to an organic electronic element on which an inorganic vapor-deposited film (chemical vapor deposition film) was formed. Thereafter, the composition was irradiated with UV of 1 J/cm.sup.2 at an intensity of 50 mW/cm.sup.2, and the curing was carried out by applying heat at 100° C. for 30 minutes. The cured encapsulating layer was allowed to stand in an environment with a temperature of 85° C. and 85% R.H. for 1000 hours, and then the luminescence shape was observed. It was classified as O in the case of no dark spot growth due to foreign substances, Δ in the case where progressive dark spots of foreign substance part were observed and X in the case where progressive dark spots of foreign substance and other dark spots part occurred.

(37) 5. Measurement of Yellow Index

(38) The adhesive compositions prepared in Examples and Comparative Examples were each applied between non-alkali glasses (0.7 T), and then irradiated with UV of 1 J/cm.sup.2 at an intensity of 50 mW/cm.sup.2 and heated at 100° C. for 30 minutes to form an encapsulating layer having a thickness of 100 μm.

(39) The YI (yellow index) value was measured according to ASTM D 1003 standard using a COH 400 transmittance meter from Nippon Denshoku.

(40) 5. Out Gas Measurement

(41) The adhesive compositions prepared in Examples and Comparative Examples were each immersed in a head space vial, then irradiated with UV of 1 J/cm.sup.2 at an intensity of 50 mW/cm.sup.2, and the photo-cured vial was placed in a head space sampler and subjected to GC mass analysis under heat curing conditions (at 100° C. for 30 minutes). The area for each component in the sample was converted to the weight relative to toluene as the reference material, and then divided by the weight of the sample to calculate the out gas content.

(42) TABLE-US-00001 TABLE 1 High temperature and high Viscosity Pot life Hardness humidity test YI Out gas Example 1  87 cps 149 hours 43 ◯ 0.75 50 ppm 2 105 cps  99 hours 53 ◯ 0.78 32 ppm 3 101 cps 118 hours 41 ◯ 0.73 81 ppm 4 164 cps 102 hours 39 ◯ 0.81 43 ppm 5 156 cps  34 hours 47 ◯ 4.8 40 ppm Comparative 1  54 cps  78 hours not measurable X 0.88 251 ppm  Example 2  92 cps 490 hours 58 Δ 0.91 77 ppm 3 156 cps 158 hours 96 ◯ 4.2 29 ppm 4 131 cps  20 hours 90 Δ 3.5 21 ppm 5 5,200 cps   151 hours 45 Δ 4.7 20 ppm 6  38 cps 180 hours 15 X 0.78 421 ppm  7  46 cps  80 hours 62 X 0.73 150 ppm