THERMOSETTING RESIN COMPOSITION AND ENCAPSULATION FILM USING THE SAME

Abstract

The present disclosure relates to a thermosetting resin composition, an encapsulation film, and an organic electronic device comprising the same, which is capable of forming a structure that can block moisture or oxygen flowing into an organic electronic device from the outside, and is intended to implement heat resistance and durability of the organic electronic device under severe conditions such as high temperatures.

Claims

1. An encapsulation film, comprising: an encapsulation layer including an encapsulation resin containing an olefin-based resin having a thermosetting functional group, wherein the encapsulation layer has a concentration of chlorine ion residues of 1,000 ppm or less as measured by combustion ion chromatography (IC), and wherein the encapsulation layer has an elastic portion (Ep) of 46% or more as calculated by General Formula 1:
Ep (%)=100×σ.sub.2/σ.sub.1  [General Formula 1] wherein, σ.sub.1 is a stress value measured 1 second after applying a strain of 30% to a specimen, wherein the specimen is prepared by laminating the encapsulation layer to a film having a size of 20 cm×30 cm and a thickness of 600 μm, and then loaded by applying a normal force of 150 gf at 85° C. thereto in a stress relaxation mode with ARES (Advanced Rheometric Expansion System) using a parallel plate in a laminated state, and wherein σ.sub.2 is a stress value measured after maintaining a state of applying the strain to the specimen for 180 seconds.

2. The encapsulation film according to claim 1, wherein the encapsulation layer has a gel fraction of 70% or more as represented by General Formula 2:
Gel fraction (%)=(B/A)×100  [General Formula 2] wherein, A represents an initial mass of a specimen of the encapsulation layer, B represents a dry mass of an insoluble content of the specimen of the encapsulation layer that does not pass through a 200 mesh (pore size 200 μm) net when the specimen of the encapsulation layer is immersed in 70 g of toluene at 60° C. for 3 hours and then filtered through the 200 mesh.

3. The encapsulation film according to claim 1, wherein the encapsulation resin is a reaction product of a thermosetting resin composition comprising a peroxide (α), an acidic solution (β) and an olefin-based resin (γ), which comprises the olefin-based resin having a thermosetting functional group.

4. The encapsulation film according to claim 3, wherein a weight ratio (α/β) of the peroxide (α) to the acidic solution (β) satisfies a range of 200 or less, and wherein the peroxide (α) is contained in an amount of 1.2 parts by weight or more relative to 100 parts by weight of the olefin-based resin (γ).

5. The encapsulation film according to claim 1, wherein the olefin-based resin (γ) comprises a copolymer of diene and an olefin-based compound containing one carbon-carbon double bond.

6. The encapsulation film according to claim 1, wherein the thermosetting functional group comprises a hydroxyl group, a carboxyl group, an amino group or an epoxy group.

7. The encapsulation film according to claim 1, wherein the thermosetting functional group is derived from an unsaturated group in the olefin-based resin.

8. The encapsulation film according to claim 1, wherein the encapsulation resin has a weight average molecular weight of 100,000 to 2,000,000 g/mol.

9. The encapsulation film according to claim 1, wherein the encapsulation layer further comprises a curing agent.

10. The encapsulation film according to claim 9, wherein the curing agent is contained in an amount of 0.1 to 10 parts by weight relative to 100 parts by weight of the encapsulation resin.

11. The encapsulation film according to claim 9, wherein the curing agent comprises an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an aziridine-based crosslinking agent, a metal chelate-based crosslinking agent, an amine-based crosslinking agent or an amino resin-based crosslinking agent.

12. The encapsulation film according to claim 1, wherein the encapsulation layer further comprises a moisture adsorbent.

13. The encapsulation film according to claim 12, wherein the moisture adsorbent is a chemically reactive adsorbent.

14. The encapsulation film according to claim 12, wherein the moisture adsorbent is contained in a range of 20 to 200 parts by weight relative to 100 parts by weight of the encapsulation resin.

15. The encapsulation film according to claim 1, comprising a multi-layered encapsulation layer.

16. A method for producing an encapsulation film, comprising: producing an encapsulation resin comprising an olefin-based resin having a thermosetting functional group using a thermosetting resin composition including a peroxide (α), an acidic solution (β) and an olefin-based resin (γ), wherein the weight ratio (α/β) of the peroxide (α) to the acidic solution (β) satisfies a range of 200 or less, and wherein the peroxide (α) is included in an amount of 1.2 parts by weight or more relative to 100 parts by weight of the olefin-based resin (γ).

17. The method for producing an encapsulation film according to claim 16, wherein the olefin-based resin (γ) reacts with the peroxide (α) for 6 hours to 40 hours during the producing step.

18. An organic electronic device, comprising: a substrate; an organic electronic element formed on the substrate; and the encapsulation film according to claim 1 encapsulating a top surface of the organic electronic element.

19. A method for manufacturing an organic electronic device, comprising: a step of applying the encapsulation film according to claim 1 to a substrate, on which an organic electronic element is formed, and cover the organic electronic element with the encapsulation film.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0117] FIGS. 1 and 2 are cross-sectional diagrams illustrating an encapsulation film according to one example of the present application.

[0118] FIG. 3 is a cross-sectional diagram illustrating an organic electronic device according to one example of the present application.

EXAMPLES

[0119] Hereinafter, the present disclosure will be described in more detail through examples according to the present disclosure and comparative examples not according to the present disclosure, but the scope of the present disclosure is not limited by the following examples.

[0120] <Encapsulation Resin>

Preparation Example 1

[0121] An isobutylene-isoprene rubber (IIR, Cenway IIR-532) having a weight average molecular weight of 570,000 g/mol was prepared and dissolved in toluene at about 20%.

[0122] In a 2 L reactor in which nitrogen gas is refluxed and a cooling device is installed for easy temperature control, 3 parts by weight of meta-chloroperoxybenzoic acid (mCPBA) relative to 100 parts by weight of the isobutylene-isoprene rubber was introduced thereto, and then stirred at 30° C. for 8 hours to perform an epoxidation reaction.

[0123] Subsequently, an aqueous hydrochloric acid solution prepared by dissolving 0.12 parts by weight of hydrochloric acid (HCl) relative to 100 parts by weight of the isobutylene-isoprene rubber in 1 part by weight of distilled water was introduced thereto, stirred at 30° C. for 1 hour, and then heated to 90° C. and stirred for 1 hour. Thus, a hydroxyl group-introduced isobutylene-isoprene rubber (IIR-OH IR), in which hydroxyl groups (thermosetting functional groups) were grafted to the isoprene units of the main chain, having a solid content of 26% and a weight average molecular weight (Mw) of 580,000 g/mol as an encapsulation resin was prepared.

Preparation Examples 2 to 12

[0124] Hydroxyl group-introduced isobutylene-isoprene rubbers (IIR-OH IRs) as the encapsulation resin were prepared in the same manner as in Preparation Example 1, except for parts by weight of meta-chloroperoxybenzoic acid (mCPBA), parts by weight of hydrochloric acid (HCl), epoxidation reaction times and weight average molecular weights shown in Table 1 below.

Comparative Preparation Examples 1 to 5

[0125] Hydroxyl group-introduced isobutylene-isoprene rubbers (IIR-OH IRs) as the encapsulation resin were prepared in the same manner as in Preparation Example 1, except for parts by weight of meta-chloroperoxybenzoic acid (mCPBA), parts by weight of hydrochloric acid (HCl), epoxidation reaction times and weight average molecular weights shown in Table 1 below.

[0126] Table 1 below summarizes the contents of the respective reactants according to Preparation Examples and Comparative Preparation Examples, which shows parts by weight of meta-chloroperoxybenzoic acid (mCPBA) and parts by weight of hydrochloric acid (HCl) introduced to form the aqueous hydrochloric acid solution, relative to 100 parts by weight of isobutylene-isoprene rubber (IIR), epoxidation reaction times, and weight average molecular weights of the hydroxyl group-introduced isobutylene-isoprene rubbers obtained from Preparation Examples and Comparative Preparation Examples.

TABLE-US-00001 TABLE 1 Epoxidation Weight average reaction time molecular weight mCPBA HCl (hour) (g/mol) Preparation 1 3 0.12 8 580,000 Example 2 2.5 0.08 8 570,000 3 2.5 0.08 8 570,000 4 2.5 0.04 12 570,000 5 2.5 0.04 12 570,000 6 2 0.02 12 560,000 7 2 0.08 12 560,000 8 2 0.08 12 580,000 9 1.5 0.01 24 570,000 10 1.5 0.08 12 570,000 11 1.5 0.08 24 570,000 12 1.5 0.08 24 570,000 Comparative 1 2.5 0.01 6 570,000 Preparation 2 1 0.01 6 570,000 Example 3 1 0.01 8 580,000 4 0.5 0.01 24 570,000 5 3 0.12 8 580,000

[0127] <Encapsulation Layer>

Example 1

[0128] 0.81 parts by weight of an isocyanate-based curing agent (Asahi Kasei, Duranate™ TKA-100), 0.7 parts by weight of a tin catalyst (DBTDL) as a reaction accelerator, and 3.1 parts by weight of acetylacetone (Sigma-Aldrich) as a curing retardant were introduced, relative to 100 parts by weight of the hydroxyl group-introduced isobutylene-isoprene rubber obtained according to Preparation Example 1 of the encapsulation resin, and additionally a calcium oxide (CaO) dispersion was mixed so that the amount of calcium oxide (CaO) was 110 parts by weight as a moisture adsorbent, and the solid content was made with toluene to be 14 wt %, thereby preparing a thermosetting resin composition.

[0129] The thermosetting resin composition was applied to the release surface of a release PET and dried in an oven at 130° C. for 3 minutes and 30 seconds to prepare an encapsulation layer with a thickness of 40 μm.

Examples 2 to 12

[0130] Encapsulation layers were prepared in the same manner as in Example 1, except for parts by weight of the curing agent shown in Table 2 below relative to 100 parts by weight of the respective hydroxyl group-introduced isobutylene-isoprene rubbers obtained according to Preparation Examples 2 to 12.

Comparative Examples 1 to 5

[0131] Encapsulation layers were prepared in the same manner as in Example 1, except for parts by weight of the curing agent shown in Table 2 below relative to 100 parts by weight of the respective hydroxyl group-introduced isobutylene-isoprene rubbers obtained according to Comparative Preparation Examples 1 to 5.

[0132] Table 2 below shows the weight parts of the added curing agent in Examples 2 to 12 and Comparative Examples 1 to 5, relative to 100 parts by weight of the respective hydroxyl group-introduced isobutylene-isoprene rubbers obtained according to Preparation Examples 1 to 12 and Comparative Preparation Examples 1 to 5.

TABLE-US-00002 TABLE 2 Curing agent Preparation 1 0.81 Example 2 0.81 3 2.43 4 0.81 5 2.43 6 0.81 7 0.81 8 2.43 9 0.81 10 0.81 11 0.81 12 2.43 Comparative 1 0.81 Preparation 2 0.81 Example 3 0.81 4 0.81 5 0

Comparative Example 6

[0133] To a butyl rubber (Cenway IIR-532) as an encapsulation resin, a hydrocarbon resin (SU-525) as a tackifier was mixed in a weight ratio of 53:47, and 15 parts by weight of a bifunctional acrylate (TCDDA, tricyclodecane dimethanol diacrylate) and 3 parts by weight of a Ni dispersion as a bright spot inhibitor were mixed, relative to 100 parts by weight of the butyl rubber and the tackifier. As a radical initiator, 2,2-dimethoxy-1,2-diphenylethan-1-one (Irgacure 651, Ciba) was introduced thereto in an amount of 0.2 parts by weight relative to the difunctional acrylate, and additionally a calcium oxide (CaO) dispersion was mixed so that the amount of calcium oxide (CaO) was 75 parts by weight as a moisture adsorbent, based on 100 parts by weight of the butyl rubber, the tackifier, the difunctional acrylate and the radical initiator in total, and the mixture was diluted with toluene so that the solid content was 36 wt %, thereby preparing an encapsulation layer solution.

[0134] The encapsulation layer solution was applied to the release surface of a release PET, and dried at 130 for 3 minutes in a dryer machine to form an encapsulation layer having a thickness of 40 μm, and then irradiated with light energy of 1.5 J/cm.sup.2 UV-A to prepare a photocured product.

Experimental Example 1—Concentration of Chlorine Ion Residues

[0135] 0.1 g of each of the encapsulation layers prepared in Examples and Comparative Examples was prepared, and the concentration of chlorine ion residues was measured by combustion ion chromatography (C-IC).

[0136] Measurement was performed after equipment stabilization, and was performed using IC (Dionox' ICS-5000DP) and AQF (Mitsubishi's AQF-2100H), where the standard material and the sample were set to the following IC conditions to perform a quantitative analysis. [0137] Combustion temperature: Inlet temperature 900° C., Outlet temperature 1,000° C. [0138] Gas flow rate: Ag gas 200 mL/min, 02 gas 400 mL/min [0139] Main column: Dionex IonPac AS18 analytical (4 mm×250 mm) [0140] Guard column: Dionex IonPac AG18 guard (4 mm×50 mm) [0141] Eluent: 30.5 mM KOH [0142] Eluent flow rate: 1 mL/min [0143] Sample injection volume: 20 μL [0144] Detector: Suppressed Conductivity Detector [0145] SRS current: 76 mA [0146] Isocratic/Gradient condition: Isocratic

Experimental Example 2—Elastic Portion Test

[0147] After laminating each of the encapsulation layers prepared in Examples and Comparative Examples to a size of 20×30 cm and a thickness of 600 μm to prepare a film specimen, a normal force of about 150 gf was applied at 85° C. using a parallel plate by means of ARES (Advanced Rheometric Expansion System, TA's ARES-G2) in the stress relaxation (relaxation test) mode to apply a strain of 30% to the specimen, and then the maximum stress value was measured several times with an interval of 1 second, whereby the average value σ.sub.1 was measured. In addition, after maintaining the state where the strain was applied to the specimen for 180 seconds, σ.sub.2, the stress value measured at 180 seconds, was additionally measured and the elastic portion (Ep, unit: %) according to the following general formula 1 was calculated.

Ep (%)=100×σ.sub.2/σ.sub.1  [General Formula 1]

[0148] In the above measurement, it must be noted that there are no air bubbles when loading the pressure-sensitive adhesive film between the flat plates.

Experimental Example 3—Gel Fraction Test

[0149] For each of the encapsulation layers of Examples and Comparative Examples, 0.3 to 0.4 g of the encapsulation layer (initial weight: A) was collected, and the encapsulation layer was immersed in 70 g of toluene at 60° C. for 3 hours. Thereafter, the gel portion was filtered with a 200-mesh wire net (weight of wire net: M), and then dried in an oven at 125° C. for 1 hour. After measuring the combined weight (G) of the gel and the wire net, the gel fraction (unit: %) was calculated according to the following general formula 2 from the gel fraction (unit: %) the dry mass (B=G-M) of the insoluble content of the encapsulation layer that did not pass through the net.

Gel content (%)=(B/A)×100  [General Formula 2]

Experimental Example 4—Measurement of Storage Elastic Modulus

[0150] For each of the encapsulation layers of Examples and Comparative Examples above, dynamic viscoelasticity was measured according to JIS K7244-4 (frequency 1 Hz, temperature increase rate 2° C./min), and storage elastic modulus (unit: Pa) at 85° C. in the shear mode was calculated.

Experimental Example 5—High-Temperature Reliability Evaluation

[0151] For each of the encapsulation layers prepared in Examples and Comparative Examples, a metal layer was laminated thereon to prepare a film sample. The film sample was bonded together on a glass substrate (0.5 T) and stored at 85° C. and 85% relative humidity for 900 hours, and it was evaluated whether the encapsulation film was lifted or bubbles were generated (oblique bubble phenomenon) according to panel warpage on the substrate. It was classified in the case without film sample lifting or bubble occurrence as O, and it was classified in the case with lifting or bubble occurrence as X.

[0152] Table 3 below summarizes the experimental results of Experimental Examples 1 to 5.

TABLE-US-00003 TABLE 3 Con- centration Storage of chlorine Elastic Gel elastic High- ion residues portion fraction modulus temperature (ppm) (Ep, %) (%) (Pa) reliability Example 1 997 82 94 161,548 ◯ 2 735 84 96 168,124 ◯ 3 735 85 97 159,101 ◯ 4 640 68 91 143,669 ◯ 5 640 84 96 165,481 ◯ 6 475 77 92 132,939 ◯ 7 580 78 92 159,190 ◯ 8 580 81 94 193,475 ◯ 9 375 53 91 122,971 ◯ 10 480 65 91 138,975 ◯ 11 479 81 89 152,113 ◯ 12 479 83 90 156,630 ◯ Com- 1 570 45 92 119,990 X parative 2 1137 83 95 116,291 ◯ Example 3 235 9 1 98,990 X 4 115 8 1 85,760 X 5 1035 — 0 unmeasurable X 6 338 24 60 109,854 X

[0153] Although the present disclosure was described with reference to the above examples, it will be understood by those skilled in the relevant technical field that the present disclosure can be variously modified and changed within the range without departing from the ideas and regions of the present disclosure as described in the following claims.