Encapsulating composition

Abstract

The present application relates to an encapsulating composition, a method for preparing the same and an organic electronic device comprising the same, and provides an encapsulating composition which can effectively block moisture or oxygen introduced into an organic electronic device from the outside to secure the lifetime of the organic electronic device, is possible to realize a top emission type organic electronic device, is applicable to an inkjet method, can provide a thin display and can control moisture content to prevent damage to the element.

Claims

1. An encapsulating composition for encapsulating an organic electronic device (OED) comprising: an epoxy compound, and a compound having an oxetane group in a range of 45 parts by weight to 145 parts by weight relative to 100 parts by weight of the epoxy compound, wherein the compound having an oxetane group has a weight average molecular weight in a range of 150 to 1,000 g/mol and a boiling point in a range of 90 to 270° C., wherein the encapsulating composition is a solventless composition and a composition configured for inkjet process, wherein the encapsulating composition has a viscosity in a range of 1 to 46 cPs as measured by Brookfield's DV-3 at a temperature of 25° C., a torque of 90% and a shear rate of 100 rpm, and wherein the composition has a moisture content of 1000 ppm or less according to a Karl Fischer coultometric titration method for 100 mg of the composition.

2. The encapsulating composition according to claim 1, wherein after curing, the amount of volatile organic compounds measured after maintaining 50 mg of the cured product at 110° C. for 30 minutes using Purge & Trap-gas chromatography/mass spectrometry, is less than 100 ppm.

3. The encapsulating composition according to claim 1, wherein the epoxy compound has at least bifunctionality or more.

4. The encapsulating composition according to claim 1, wherein the epoxy compound comprises a compound having a cyclic structure in its molecular structure and/or a linear or branched aliphatic compound.

5. The encapsulating composition according to claim 4, wherein the compound having a cyclic structure in its molecular structure has ring constituent atoms in the molecular structure in a range of 3 to 10.

6. The encapsulating composition according to claim 4, wherein the linear or branched aliphatic compound is comprised in a range of 20 parts by weight or more and less than 205 parts by weight relative to 100 parts by weight of the compound having a cyclic structure.

7. The encapsulating composition according to claim 1, further comprising a surfactant.

8. The encapsulating composition according to claim 7, wherein the surfactant comprises a polar functional group.

9. The encapsulating composition according to claim 7, wherein the surfactant comprises a fluorine-based compound.

10. The encapsulating composition according to claim 7, wherein the surfactant is comprised in an amount of 0.01 parts by weight to 10 parts by weight relative to 100 parts by weight of the epoxy compound.

11. The encapsulating composition according to claim 1, further comprising a photoinitiator.

12. The encapsulating composition according to claim 11, wherein the photoinitiator is comprised in an amount of 1 to 15 parts by weight relative to 100 parts by weight of the epoxy compound.

13. A method for preparing the encapsulating composition of claim 1, comprising steps of: removing moisture from a solventless encapsulating composition without any photoinitiator; and mixing a photoinitiator with the encapsulating composition.

14. The method according to claim 13, wherein the moisture removal step comprises heating and cooling the encapsulating composition or mixing an inert gas therewith.

15. The method according to claim 13, wherein the moisture removal step proceeds at a constant pressure.

16. The method according to claim 15, wherein the moisture removal step proceeds in a state where the pressure is constantly maintained at any one pressure of 0.5 to 2 atm.

17. The method according to claim 15, wherein the constant pressure has an error range of −0.5 to 0.5 atm.

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

19. A method for manufacturing an organic electronic device comprising a step of forming an organic layer on a substrate in which an organic electronic element is formed on its upper part, so that the encapsulating composition of claim 1 seals the entire surface of the organic electronic element.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIGS. 1 and 2 are cross-sectional views showing an organic electronic device according to one example of the present invention.

EXPLANATION OF REFERENCE NUMERALS

(2) 3: organic electronic device 31: substrate 32: organic electronic element 33: organic layer 34: inorganic layer 35: protective layer 36: sealing structure 37: encapsulation film 38: cover substrate

BEST MODE

(3) Hereinafter, the present invention will be described in more detail through 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 compound (Celloxide 2021P, Daicel Corp.) and an aliphatic epoxy compound (DE203, HAJIN CHEM TECH) as epoxy compounds, an oxetane group-containing compound (OXT-221 from TOAGOSEI) and a fluorine-based surfactant (F552 from DIC) were each introduced into a mixing vessel in a weight ratio of 23.8:28.7:37.5:1.0 (Celloxide2021P:DE203:OXT-221:F552) at room temperature.

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

(6) The composition ink is subjected to a moisture removal step. In the mixing vessel, nitrogen sparging is started for the prepared encapsulating composition, and the temperature is raised to 85° C. through a circulator to continue the sparging for 3 hours. Thereafter, the circulator is cooled to room temperature.

(7) To the encapsulating composition, a photoinitiator (I290) was mixed at a ratio of 5 parts by weight to prepare a uniform encapsulating composition ink.

Example 2

(8) An encapsulating composition was prepared in the same manner as in Example 1, except that in the mixing vessel, the nitrogen sparging was started for the prepared encapsulating composition and the temperature was raised to 85° C. through a circulator to continue the sparging for 1 hour.

Example 3

(9) An alicyclic epoxy compound (Celloxide 2021P, Daicel Corp.) and an aliphatic epoxy compound (DE203, HAJIN CHEM TECH) as epoxy compounds, an oxetane group-containing compound (OXT-221 from TOAGOSEI) and a fluorine-based surfactant (F552 from DIC) were each introduced into a mixing vessel in a weight ratio of 23.8:28.7:37.5:1.0 (Celloxide2021P:DE203:OXT-221:F552) at room temperature.

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

(11) The composition ink is subjected to a moisture removal step. In the mixing vessel, the prepared encapsulating composition is heated and dried under a reduced pressure condition.

(12) Thereafter, to the encapsulating composition, a photoinitiator (I290) was mixed at a ratio of 5 parts by weight to prepare a uniform encapsulating composition ink.

Example 4

(13) An encapsulating composition was prepared in the same manner as in Example 3, except that in the moisture removal step, it was distilled and purified under a reduced pressure condition.

Comparative Example 1

(14) An encapsulating composition was prepared in the same manner as in Example 1, except that no moisture removal step was performed.

Comparative Example 2

(15) An alicyclic epoxy compound (Celloxide 2021P, Daicel Corp.) and an aliphatic epoxy compound (DE203, HAJIN CHEM TECH) as epoxy compounds, an oxetane group-containing compound (OXT-221 from TOAGOSEI), a photoinitiator (I290) and a fluorine-based surfactant (F552 from DIC) were each introduced into a mixing vessel in a weight ratio of 23.8:28.7:37.5:5.0:1.0 (Celloxide2021P:DE203:OXT-221:I290:F552) at room temperature.

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

(17) The composition ink is subjected to a moisture removal step. In the mixing vessel, nitrogen sparging is started for the prepared encapsulating composition, and the temperature is raised to 85° C. through a circulator to continue the sparging for 3 hours. Thereafter, the circulator is cooled to room temperature.

Comparative Example 3

(18) An alicyclic epoxy compound (Celloxide 2021P, Daicel Corp.) and an aliphatic epoxy compound (DE203, HAJIN CHEM TECH) as epoxy compounds, an oxetane group-containing compound (OXT-221 from TOAGOSEI) and a fluorine-based surfactant (F552 from DIC) were each introduced into a mixing vessel in a weight ratio of 23.8:28.7:37.5:1.0 (Celloxide2021P:DE203:OXT-221:F552) at room temperature, and the mixture was diluted with 2-butoxyethanol as a solvent so that the epoxy compounds were about 90% by weight to prepare a coating solution.

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

(20) The composition ink is subjected to a moisture removal step. In the mixing vessel, nitrogen sparging is started for the prepared encapsulating composition, and the temperature is raised to 85° C. through a circulator to continue the sparging for 3 hours. Thereafter, the circulator is cooled to room temperature.

(21) To the encapsulating composition, a photoinitiator (I290) was mixed at a ratio of 5 parts by weight to prepare a uniform encapsulating composition ink.

Comparative Example 4

(22) An encapsulating composition was prepared in the same manner as in Comparative Example 3, except that no moisture removal step was performed.

(23) Physical properties in Examples and Comparative Examples were evaluated in the following manner.

(24) 1. Moisture Content Measurement

(25) The moisture content of the encapsulating compositions prepared in Examples and Comparative Examples was measured by using Karl Fischer titrators-831 KF Coulometer-coulometric from Metrohm. The moisture content was measured using Karl Fischer coulometric titration for 100 mg of the composition. Also, the measurement was performed at a temperature of 25° C., performed in an airtight container and adjusted to an equivalent point of 50 mV within an appropriate speed range of 0.3 to 2240 μg/min.

(26) 2. Outgas Measurement

(27) The encapsulating compositions prepared in Examples and Comparative Examples were each cured by irradiation with UV of 1 J/cm.sup.2 at an intensity of 1000 mW/cm.sup.2, and 50 mg of each sample of the cured products was maintained at 110° C. for 30 minutes using Purge & Trap-gas chromatography/mass spectrometry and then the amount of volatile organic compounds was measured. The measurement was performed using a Purge & Trap sampler (JAI JTD-505 III)-GC/MS (Agilent 7890b/5977a) instrument. It was represented as O in the case where the measured amount was 100 ppm or less, as Δ in the case where it was 500 ppm or less and as X in the case where it was more than 500 ppm.

(28) 4. Dark Spot Measurement

(29) The encapsulating compositions prepared in Examples and Comparative Examples were each applied on an organic electronic element on which an inorganic vapor deposition layer (chemical vapor deposition layer) was formed. Thereafter, it was irradiated with UV of 1 J/cm.sup.2 at an intensity of 1000 mW/cm.sup.2 to be subjected to curing. The cured organic layer was allowed to stand at a temperature of 85° C. and an environment of 85% R.H. for 300 hours, and then the emission type was observed. It was classified as O in the case of no dark spot by foreign materials, as Δ in the case where 1 to 2 dark spots were observed and as X in the case where 3 or more dark spots were much generated and thus light emitting was impossible.

(30) TABLE-US-00001 TABLE 1 Moisture content (ppm) Outgas Dark spot Example 1 98 ◯ ◯ Example 2 532 ◯ Δ Example 3 120 Δ Δ Example 4 210 Δ Δ Comparative Example 1 1004 ◯ X Comparative Example 2 not not not measurable measurable measurable Comparative Example 3 669 X X Comparative Example 4 1512 X X

(31) In Comparative Example 2, partial curing progressed during the heating and cooling, and the experiment was not carried out.