Pressure sensitive adhesive film and method of manufacturing organic electronic device using the same

Abstract

Provided are a pressure-sensitive adhesive film and a method of manufacturing an organic electronic device using the same. The pressure-sensitive adhesive film that may effectively block moisture or oxygen penetrated into an organic electronic device from an external environment, and exhibit reliability under harsh conditions such as high temperature and high humidity and excellent optical characteristics is provided.

Claims

1. A pressure-sensitive adhesive film, comprising: a pressure-sensitive adhesive having an elastic portion (Ep) calculated by Equation 1 of 20 to 80%, wherein the pressure-sensitive adhesive film has a water vapor transmission rate in a thickness direction of 50 g/m.sup.2.Math.day or less:
Ep (unit: %)=100×σ2/σ1  [Equation 1] wherein σ1 is the maximum stress value measured when 50% strain is applied to the film by applying 200 gf of normal force with a parallel plate in a relaxation test mode at 80° C. using an advanced rheometric expression system (ARES) while a pressure-sensitive adhesive film is manufactured to have a thickness of 600 μm, and σ2 is a stress value measured after the film is maintained for 180 seconds while the strain is applied to the film.

2. The film according to claim 1, which has a gel content represented by Equation 2 of 50% or more:
Gel content (wt %)=B/A×100  [Equation 2] wherein A is a weight of the pressure-sensitive adhesive, and B is a dry weight of an insoluble content of the pressure-sensitive adhesive remaining after being dipped in toluene at 60° C. for 24 hours and filtered through a 200-mesh sieve (pore size of 200 μm).

3. The film according to claim 1, wherein the pressure-sensitive adhesive comprises a pressure-sensitive adhesive composition comprising an encapsulating resin and a multifunctional active energy ray-polymerizable compound.

4. The film according to claim 3, wherein the encapsulating resin is a copolymer of a diene and an olefin-based compound having one carbon-carbon double bond.

5. The film according to claim 3, wherein the active energy ray-polymerizable compound is a multifunctional acrylate.

6. The film according to claim 3, wherein the active energy ray-polymerizable compound satisfies Formula 1: ##STR00003## wherein R.sub.1 is hydrogen or an alkyl group having 1 to 4 carbon atoms, n is an integer of 2 or more, and X is a residue induced from a linear, branched or cyclic alkyl group having 3 to 30 carbon atoms.

7. The film according to claim 3, wherein the active energy ray-polymerizable compound is included at 5 to 30 parts by weight relative to 100 parts by weight of the encapsulating resin.

8. The film according to claim 3, wherein the pressure-sensitive adhesive composition further comprises a silane compound satisfying Formula 2: ##STR00004## wherein R.sub.1 is hydrogen or an alkyl group, R.sub.2 and R.sub.3 are each independently hydrogen, or a linear, branched or cyclic alkyl group, or R.sub.2 being linked with R.sub.3, thereby forming a cyclic alkyl group, R.sub.4, R.sub.5 and R.sub.6 are each independently hydrogen, an alkyl group or an alkoxy group, at least one of R.sub.4, R.sub.5 and R.sub.6 being an alkoxy group, and n is an integer of 1 or more.

9. The film according to claim 8, wherein the silane compound satisfying Formula 2 is included at 0.1 to 10 parts by weight relative to 100 parts by weight of the encapsulating resin.

10. The film according to claim 3, wherein the pressure-sensitive adhesive composition further comprises a tackifier.

11. The film according to claim 10, wherein the tackifier is included at 5 to 100 parts by weight relative to 100 parts by weight of the encapsulating resin.

12. The film according to claim 3, wherein the pressure-sensitive adhesive composition further comprises a radical initiator.

13. The film according to claim 1, wherein the pressure-sensitive adhesive comprises a moisture absorbent.

14. The film according to claim 1, which comprises a first layer having the pressure-sensitive adhesive and a second layer having a pressure-sensitive adhesive resin or an adhesive resin.

15. A product for encapsulating an organic electronic device, comprising: a substrate; an organic electronic element formed on the substrate; and the pressure-sensitive adhesive film according to claim 1 to encapsulate the organic electronic element.

16. A method of manufacturing an organic electronic device, comprising: applying the pressure-sensitive adhesive film of claim 1 to a substrate on which an organic electronic element is formed in order to cover the organic electronic element; and curing the pressure-sensitive adhesive film.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1 and 2 are cross-sectional views of pressure-sensitive adhesive films according to exemplary embodiments of the present invention;

(2) FIG. 3 is a cross-sectional view of a product for encapsulating an organic electronic device according to an exemplary embodiment of the present invention; and

(3) FIGS. 4 and 5 are planar views showing results of high temperature durability tests performed on pressure-sensitive adhesive films according to exemplary embodiments of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

(4) 1, 2: pressure-sensitive adhesive film

(5) 11: pressure-sensitive adhesive

(6) 12: first film

(7) 21: second film

(8) 3: organic electronic device

(9) 31: substrate

(10) 32: organic electronic element

(11) 33: pressure-sensitive adhesive or encapsulating layer

(12) 34: cover substrate

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

(13) Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the scope of the present invention is not limited to the following Examples.

EXAMPLE 1

(14) A coating solution was prepared by adding 80 g of a butyl rubber as an encapsulating resin, 20 g of tricyclodecane dimethanol diacrylate (SR833S, Sartomer Company Inc.) as an active energy ray-polymerizable compound, 0.2 g of 3-methacryloxypropyl trimethoxysilane (Sigma-Aldrich Co. LLC.) as a silane compound, and 1 g of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure651, Ciba Specialty Chemicals Corporation) as a radical initiator, and diluting the mixture in toluene to have a solid content of approximately 20 wt %.

(15) The prepared solution was coated on a released surface of release PET, and dried in an oven at 100° C. for 5 minutes, thereby manufacturing a pressure-sensitive adhesive film including a pressure-sensitive adhesive having a thickness of 30 μm. Physical properties of the sample were measured after a UV ray was irradiated at 2 J/cm.sup.2 on the manufactured film.

EXAMPLE 2

(16) A coating solution was prepared by adding 50 g of a butyl rubber as an encapsulating resin, 35 g of a hydrogenated DCPD-based tackifier (SU-125, Kolon Industries, Inc.) as a tackifier, 15 g of tricyclodecane dimethanol diacrylate (SR833S, Sartomer Company Inc.) as an active energy ray-polymerizable compound, 0.2 g of 3-methacryloxypropyl trimethoxysilane (Sigma-Aldrich Co. LLC.) as a silane compound, and 1 g of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure651, Ciba Specialty Chemicals Corporation) as a radical initiator, and diluting the mixture in toluene to have a solid content of approximately 30 wt %. Here, a coating solution was prepared by adding 10 g of calcium oxide (Sigma-Aldrich Co. LLC.) ball-milled with 10 g of toluene to the above solution.

(17) The prepared solution was coated on a released surface of release PET, and dried in an oven at 100° C. for 5 minutes, thereby manufacturing a pressure-sensitive adhesive film having a thickness of 30 μm. Physical properties of the sample were measured after a UV ray was irradiated at 3 J/cm.sup.2 on the manufactured film.

EXAMPLE 3

(18) A coating solution was prepared by adding 60 g of a butyl rubber as an encapsulating resin, 30 g of a hydrogenated DCPD-based tackifier (SU-125, Kolon Industries, Inc.) as a tackifier, 10 g of tricyclodecane dimethanol diacrylate (SR833S, Sartomer Company Inc.) as an active energy ray-polymerizable compound, 0.2 g of 3-methacryloxypropyl trimethoxysilane (Sigma-Aldrich Co. LLC.) as a silane compound, and 1 g of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure651, Ciba Specialty Chemicals Corporation) as a radical initiator, and diluting the mixture in toluene to have a solid content of approximately 20 wt %.

(19) The prepared solution was coated on a released surface of release PET, and dried in an oven at 100° C. for 5 minutes, thereby manufacturing a pressure-sensitive adhesive film having a thickness of 30 μm. Physical properties of the sample were measured after a UV ray was irradiated at 2 J/cm.sup.2 on the manufactured film.

EXAMPLE 4

(20) A coating solution was prepared by adding 60 g of a butyl rubber as an encapsulating resin, 20 g of a hydrogenated DCPD-based tackifier (SU-125, Kolon Industries, Inc.) as a tackifier, 20 g of tricyclodecane dimethanol diacrylate (SR833S, Sartomer Company Inc.) as an active energy ray-polymerizable compound, 0.2 g of 3-methacryloxypropyl trimethoxysilane (Sigma-Aldrich Co. LLC.) as a silane compound, and 1 g of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure651, Ciba Specialty Chemicals Corporation) as a radical initiator, and diluting the mixture in toluene to have a solid content of approximately 20 wt %.

(21) The prepared solution was coated on a released surface of release PET, and dried in an oven at 100° C. for 5 minutes, thereby manufacturing a pressure-sensitive adhesive film having a thickness of 30 μm. Physical properties of the sample were measured after a UV ray was irradiated at 2 J/cm.sup.2 on the manufactured film.

COMPARATIVE EXAMPLE 1

(22) A pressure-sensitive adhesive film was manufactured by the same method as described in Example 1, except that polyisobutylene was used as an encapsulating resin, instead of a butyl rubber.

COMPARATIVE EXAMPLE 2

(23) A coating solution was prepared by adding 55 g of a butyl rubber as an encapsulating resin, 20 g of a hydrogenated DCPD-based tackifier (SU-125, Kolon Industries, Inc.) as a tackifier, 35 g of tricyclodecane dimethanol diacrylate (SR833S, Sartomer Company Inc.) as an active energy ray-polymerizable compound, 0.2 g of 3-methacryloxypropyl trimethoxysilane (Sigma-Aldrich Co. LLC.) as a silane compound, and 1 g of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure651, Ciba Specialty Chemicals Corporation) as a radical initiator, and diluting the mixture in toluene to have a solid content of approximately 20 wt %.

(24) The prepared solution was coated on a released surface of release PET, and dried in an oven at 100° C. for 5 minutes, thereby manufacturing a pressure-sensitive adhesive film having a thickness of 30 μm. Physical properties of the sample were measured after a UV ray was irradiated at 2 J/cm.sup.2 on the manufactured film.

COMPARATIVE EXAMPLE 3

(25) A coating solution was prepared by adding and homogenizing 60 g of 2-ethylhexylacrylate (Sigma-Aldrich Co. LLC.), 30 g of butyl acrylate (Sigma-Aldrich Co. LLC.) and 10 g of hydroxyethylacrylate (Sigma-Aldrich Co. LLC.) as acrylic monomers, and 3 g of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure651, Ciba Specialty Chemicals Corporation) as a radical initiator.

(26) The prepared solution was coated on a released surface of release PET, thereby forming a pressure-sensitive adhesive film having a thickness of 30 μm. Physical properties of the sample were measured after a UV ray was irradiated at 2 J/cm.sup.2 on the manufactured film.

(27) 1. Elastic Portion (Ep Measurement)

(28) Values of the maximum stress σ1 were measured by laminating the pressure-sensitive adhesive films manufactured by Examples 1 to 4 and Comparative Examples 1 to 3 to have a thickness of 600 μm (pressure-sensitive adhesive layer: 600 μm), applying approximately 200 gf of normal force with a parallel plate in a relaxation test mode at 80° C. using an advanced rheometric expression system (ARES; ARES-G2 produced by TA Instruments.) to apply 50% of strain to the film. A value of stress σ2 was additionally measured at the time of 180 seconds after the strain-applied film was maintained for 180 seconds, and then Ep according to Equation 1 was calculated.
Ep (unit: %)=100×σ2/σ1  [Equation 1]

(29) During the measurement, it was careful that there was no bubble when loading the pressure-sensitive adhesive film.

(30) 2. Gel Content
Gel content (wt %)=B/A×100

(31) Here, A is a mass of the pressure-sensitive adhesive, and B is a dry mass of an insoluble content of the pressure-sensitive adhesive remaining after the pressure-sensitive adhesive was dipped in toluene at 60° C. for 24 hours and filtered through a 200-mesh sieve (pore size: 200 μm).

(32) 3. Water Vapor Transmission Rate (WVTR)

(33) A resin composition was prepared by dissolving the resin used in Example or Comparative Example in a solvent. The resin composition was applied to a base film (release polyester film) having a thickness of 38 μm. Subsequently, the composition was dried at 110° C. for 10 minutes, thereby forming a film-type pressure-sensitive adhesive layer having a thickness of 100 μm, and then 2 J/cm.sup.2 of a UV ray was irradiated. Afterward, the base film was peeled, and then a WVTR of the film-type layer was measured in a thickness direction, while a nylon mesh was attached to the film-type pressure-sensitive adhesive layer and the layer was maintained at 100° F. and a relative humidity of 100%. The WVTR was measured according to a specification of ASTM F1249.

(34) 4. Evaluation of Reliability

(35) (1) A sample was prepared by laminating the film manufactured in Example or Comparative Example on a barrier film (serving as a cover substrate), laminating the resulting product on a glass substrate, and pressure and heat-compressing the resulting product using an autoclave at 50° C. and 5 atm. Afterward, the sample was maintained in a constant temperature and constant humidity chamber at 85° C. and a relative humidity of 85% for approximately 500 hours, and observed whether lifting, bubbles or hazes were generated at an interface between a glass substrate and a pressure-sensitive adhesive layer. When being viewed with the naked eye, at the interface between the glass substrate and the pressure-sensitive adhesive layer, if at least one lifting, bubble or haze was generated, it was represented as X, and if no lifting, bubble or haze was generated, it was represented as O.

(36) (2) A sample was manufactured by the same method, except that a polarizing plate was further laminated on a barrier film in a method of evaluating reliability at 85° C. and a relative humidity of 85%, and observed to check whether lifting or bubbles were generated at an interface between a glass substrate and a pressure-sensitive adhesive while being maintained in a 80° C. chamber for approximately 500 hours. When being viewed with a naked eye, if there was at least one lifting or bubble at the interface between the glass substrate and the pressure-sensitive adhesive layer, it was represented as X, and if there was no lifting or bubble, it was represented as O.

(37) TABLE-US-00001 TABLE 1 High temperature High temperature WVTR & high humidity reliability Ep Gel (g/m.sup.2 .Math. reliability (85° (80° C., Polar- (%) (%) day) C., 85% RH) izing plate) Example1 25 51 4 ◯ ◯ Example2 35 59 4 ◯ ◯ Example3 45 67 4 ◯ ◯ Example4 72 80 5 ◯ ◯ Compar- 16 0 4 ◯ X ative Ex- ample1 Compar- 84 85 4 X X ative Ex- ample2 Compar- 50 80 >500 X ◯ ative Ex- ample3