Pressure-sensitive adhesive composition, pressure-sensitive adhesive film, and method of manufacturing organic electronic device using the same

Abstract

Provided are a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film, and a method of manufacturing an organic electronic device using the same. The pressure-sensitive adhesive composition 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, and a pressure-sensitive adhesive film including the same are provided.

Claims

1. A pressure-sensitive adhesive composition comprising an encapsulating resin comprising a copolymer of a diene and an olefin-based compound haying one carbon-carbon double bond, a tackifier and an active energy rav-polymerizable compound included at 5 to 18 parts by weight relative to 100 parts by weight of the encapsulating resin, wherein the active energy ray-polymerizable compound satisfies Formula 1: ##STR00003## where 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 inducted from a linear, branched, or cyclic alkyl group having 3 to 30 carbon atoms, wherein the pressure sensitive adhesvie composition has a gel content represented by Equation 1 of 50% or more, a micro gel content represented by Equation 2 of 3% or less, and a water vapor transmission rate in a thickness direction while being formed in a film having a thickness of 100 m of 50 g/m.sup.2, day or less:
Gel content (wt %)=B/A100 [Equation 1]
Micro gel content (wt %)=C/A100 [Equation 2] wherein in Equations 1 and 2, A is a mass of the pressure-sensitive adhesive composition, in Equation 1, B is a dry mass of an insoluble content of the pressure-sensitive adhesive composition remaining after being dipped in toluene at 60 C. for 24 hours and filtered through a 200-mesh sieve (pore size of 200 m), and in Equation 2, C is a dry mass of an insoluble content of the pressure-sensitive adhesive composition remaining after being dipped in toluene at 60 C. for 24 hours, primarily filtered through a 200-mesh sieve (pore size: 200 m), and secondarily filtered through a 1000-mesh sieve (pore size: 5 m).

2. The composition according to claim 1, which has a gel content represented by Equation 1 of 50 to 99%.

3. The composition according to claim 1, which has a light transmittance of 85% or more with respect to a visible-ray region while being formed in a film.

4. The composition according to claim 1, which has a haze of 3% or less while being formed in a film.

5. The composition according to claim 1, further comprising: a radical initiator.

6. The composition according to claim. 1, further comprising: a moisture absorbent.

7. A pressure-sensitive adhesive film, comprising a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer comprises the pressure-sensitive adhesive composition of claim 1 or a crosslinked product thereof.

8. The pressure-sensitive adhesive film according to claim 7, wherein the film comprises a first layer having the pressure-sensitive adhesive layer and a second layer having a pressure-sensitive adhesive resin or an adhesive resin.

9. The pressure-sensitive adhesive film according to claim 7, which has a light transmittance of 85% or more with respect to a visible-ray region.

10. The pressure-sensitive adhesive film according to claim 7, which has a haze of 3% or less.

11. An organic electronic device, comprising: a substrate; an organic electronic element formed on the substrate; and the pressure-sensitive adhesive film according to claim 7 encapsulate the organic electronic element.

12. A method of manufacturing an organic electronic device, comprising: applying the pressure-sensitive adhesive film of claim 7 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;

(3) FIG. 4 is a diagram showing results of a reliability test of a pressure-sensitive adhesive film according to Example 1 of the present invention; and

(4) FIG. 5 is a diagram showing results of a reliability test of a pressure-sensitive adhesive film according to Comparative Example 1 of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

(5) 1, 2: pressure-sensitive adhesive film 11: pressure-sensitive adhesive layer 12: first film 21: second film 3: organic electronic device 31: substrate 32: organic electronic element 33: pressure-sensitive adhesive layer or encapsulating layer 34: cover substrate

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

(6) 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

(7) A coating solution was prepared by adding 90 g of a butyl rubber (LANXESS, BUTYL 301) as an encapsulating resin, 10 g of a hydrogenated DCPD-based tackifier resin (SU-90, Kolon) as a tackifier, 15 g of tricyclodecane dimethanol diacrylate (M262, Miwon) as an active energy ray-polymerizable compound, and 1 g of 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure651, Ciba) as a radical initiator, and diluting the mixture in toluene to have a solid content of approximately 15 wt %.

(8) The prepared solution was coated on a released surface of release PET, and dried in an oven at 100 C. for 15 minutes, thereby manufacturing a pressure-sensitive adhesive film including a pressure-sensitive adhesive layer having a thickness of 20 m. 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

(9) A pressure-sensitive adhesive film was manufactured by the same method as described in Example 1, except that 60 g of a butyl rubber (LANXESS, BUTYL 301) and 30 g of polyisobutylene (including 25 g of BASF, B80, and 5 g of B15) were used as encapsulating resins.

Example 3

(10) A pressure-sensitive adhesive film was manufactured by the same method as described in Example 1, except that CaO (Aldrich) was added as a moisture absorbent at 20 parts by weight relative to 100 parts by weight of a butyl rubber and a tackifier resin.

Comparative Example 1

(11) A pressure-sensitive adhesive film was manufactured by the same method as described in Example 1, except that 80 g of polyisobutylene (BASF, B80) was used as an encapsulating resin, 2-hydroxyethyl acrylate (HEA, Aldrich) was added, and isophorone diisocyanate (IPDI, Aldrich) was added.

Comparative Example 2

(12) A pressure-sensitive adhesive film was manufactured by the same method as described in Example 1, except that polybutadiene dimethacrylate (CN301, Sartomer) was used as an active energy ray-polymerizable compound.

Comparative Example 3

(13) A pressure-sensitive adhesive film was manufactured by the same method as described in Example 1, except that a content of an active energy ray-polymerizable compound was changed to 3 g.

Comparative Example 4

(14) A pressure-sensitive adhesive film was manufactured by the same method as described in Example 1, except that a content of an active energy ray-polymerizable compound was changed to 0 g.

Comparative Example 5

(15) A coating solution (pressure-sensitive adhesive composition) was prepared by mixing 99 parts by weight of n-butyl acrylate and 1 part by weight of 2-hydroxyethyl methacrylate, and blending a multifunctional epoxy compound (trimethylolpropane triglycidylether), a cationic photoinitiator (triarylsulfonium hexafluoroantimonate), and -glycidoxypropyl trimethoxy silane in an acryl pressure-sensitive adhesive having a molecular weight (Mw) of approximately 1,800,000, and diluting the mixture at a suitable concentration. A pressure-sensitive adhesive layer was formed to have a thickness of approximately 50 m by coating and drying the prepared coating solution on a release-treated surface of a polyethyleneterephthalate (PET) film on which release treatment was performed, and forming a crosslinking structure by irradiating a UV ray.

Comparative Example 6

(16) A pressure-sensitive adhesive film was manufactured by the same method as described in Example 1, except that 80 g of polyisobutylene (BASF, B80) was used as an encapsulating resin instead of a butyl rubber, and 15 g of fumed silica (R812, Evonik) was added.

(17) Hereinafter, physical properties were evaluated by the following methods in the Examples and Comparative Examples.

(18) 1. Gel Content
Gel content (wt %)=B/A100

(19) Here, A is a weight of the pressure-sensitive adhesive composition, and B is a dry weight of an insoluble content of the pressure-sensitive adhesive composition remaining after the pressure-sensitive adhesive composition was dipped in toluene at 60 C. for 24 hours and filtered through a 200-mesh sieve (pore size: 200 m). In Comparative Example 5, ethyl acetate was used instead of toluene.

(20) 2. Micro Gel Content
Micro gel content (wt %)=C/A100

(21) Here, A is a weight of the pressure-sensitive adhesive composition, and C is a dry weight of the pressure-sensitive adhesive composition remaining after the pressure-sensitive adhesive composition was dipped in toluene at 60 C. for 24 hours, primarily filtered through a 200-mesh sieve (pore size: 200 m), and secondarily filtered through a 1000-mesh sieve (pore size: 5 m). In Comparative Example 5, ethyl acetate was used instead of toluene.

(22) In addition, the micro gel could be detected using a 5 m syringe. For example, when the pressure-sensitive adhesive composition was primarily filtered through a 200-mesh sieve (pore size: 200 m) and passed through a 5 m syringe, the pressure-sensitive adhesive composition having a micro gel content of more than 3% represented by Equation 2 did not pass since a syringe was clogged due to a micro gel (having a size of approximately 100 nm to 20 m) present in the composition. When the composition was not filtered, it was represented as X in Table 1. On the other hand, when there was almost no or no micro gel, the composition passed through the syringe (represented as O in Table 1), and the micro gel content represented in Equation 2 was detected at 3% or less. In addition, through morphological analysis, the presence of the micro gel could be actually confirmed.

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

(24) A resin composition was prepared by dissolving the resin used in

(25) Example or Comparative Example in a solvent. The resin composition was applied to a base film having a thickness of 38 m (release polyester film, RS-21G, SKC). Subsequently, the composition was dried at 110 C. for 10 minutes, thereby forming a film-type layer having a thickness of 100 m. Afterward, the base film was peeled, and then a WVTR of the film-type layer was measured in a thickness direction, while the layer was maintained at 100 F. and a relative humidity of 100%. The WVTR was measured according to a specification of ASTM F1249.

(26) 4. Evaluation of Reliability

(27) (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 between glass substrates, 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.

(28) (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 layer 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.

(29) 5. Measurement of Light Transmittance and Haze

(30) A light transmittance of the pressure-sensitive adhesive film manufactured as described above was measured at 550 nm using a UV-Vis spectrometer, and a haze of the pressure-sensitive adhesive film was measured using a haze meter according to a standard test method of JIS K7105.

(31) TABLE-US-00001 TABLE 1 High temperature High temperature Micro gel & high humidity reliability /X reliability 80 C., Light Gel (5 m WVTR 85 C. Polarizing transmittance Haze % % syringe) g/m.sup.2 .Math. day 85% RH plate % Example 1 74 0 4 90 0.2 Example 2 51 0 4 90 0.2 Example 3 85 0 6 Comparative 55 4.1 X 4 X 90 2.7 Example 1 Comparative 0 0 5 X X 90 0.3 Example 2 Comparative 43 0 4 X 90 0.2 Example 3 Comparative 0 0 4 X X 90 0.1 Example 4 Comparative 83 0 >500 90 0.2 Example 5 Comparative 0 0 4 X 89 1.6 Example 6