Adhesive film

Abstract

The present invention relates to an adhesive composition, an adhesive film, a method of manufacturing the adhesive film and an organic electronic device (OED) that are used to encapsulate an organic electronic element. The adhesive composition can form an encapsulant layer having an excellent adhesive property, impact resistance, heat-protecting property and moisture blocking property, so that an OED that includes an element encapsulated with the adhesive composition can exhibit an excellent lifespan property and durability.

Claims

1. An adhesive film for encapsulating an organic electronic element, comprising an adhesive layer that is in a film or sheet shape and that comprises an adhesive composition, the adhesive composition comprises: a curable adhesive resin; a moisture absorbent; a filler, and a binder resin which is a rubber component, wherein the adhesive composition is in a solid or semi-solid phase at room temperature, and has a viscosity of 10.sup.6 poise or more at 25 C. when the curable adhesive resin is in a non-cured state, wherein the curable adhesive resin is an acrylic resin, a polyester resin, an isocyanate resin, or an epoxy resin, wherein the curable adhesive resin has a water vapor transmission rate in a thickness direction of 50 g/m.sup.2.Math.day or less under a state where the curable adhesive resin is cured to be in the shape of a film, and wherein the filler is at least one selected from the group consisting of clay, talc, silica, alumina, and titania.

2. The adhesive film for encapsulating an organic electronic element of claim 1, wherein the curable adhesive resin is a silane modified epoxy resin.

3. The adhesive film for encapsulating an organic electronic element of claim 2, wherein the silane modified epoxy resin is an aromatic epoxy resin to which a silane compound of the following Chemical Formula 1 is introduced, the silane compound being introduced in an amount of 0.1 to 10 parts by weight, relative to 100 parts by weight of the aromatic epoxy resin:
D.sub.nSiX.sub.(4-n)[Chemical Formula 1] where, D is a vinyl group, an epoxy group, an amino group, an acrylic group, a methacrylic group, a mercapto group, an alkoxy group, or an isocyanate group, or an alkyl group substituted with any one of the above-mentioned functional groups; X is hydrogen, an alkyl group, a halogen, an alkoxy group, an aryl group, an aryloxy group, an acyloxy group, an alkylthio group, or an alkyleneoxythio group; and n is a number from 1 to 3.

4. The adhesive film for encapsulating an organic electronic element of claim 3, wherein the aromatic epoxy resin is a bisphenol epoxy resin.

5. The adhesive film for encapsulating an organic electronic element of claim 1, wherein the moisture absorbent is an oxide or metallic salt.

6. The adhesive film for encapsulating an organic electronic element of claim 1, wherein the moisture absorbent is comprised in an amount of 1 to 100 parts by weight, relative to 100 parts by weight of the curable adhesive resin.

7. The adhesive film for encapsulating an organic electronic element of claim 1, wherein the moisture absorbent has a mean diameter of 1 to 20 m.

8. The adhesive film for encapsulating an organic electronic element of claim 1, wherein the filler is comprised in an amount of 1 to 50 parts by weight, relative to 100 parts by weight of the curable adhesive resin.

9. The adhesive film for encapsulating an organic electronic element of claim 1, further comprising 1 to 20 parts by weight of a curing agent, relative to 100 parts by weight of the curable adhesive resin.

10. The adhesive film for encapsulating an organic electronic element of claim 1, further comprising 0.01 to 10 parts by weight of a photopolymerization initiator, relative to 100 parts by weight of the curable adhesive resin.

11. The adhesive film for encapsulating an organic electronic element of claim 1, wherein the binder resin is comprised in an amount of 200 parts by weight or less, relative to 100 parts by weight of the curable adhesive resin.

12. The adhesive film for encapsulating an organic electronic element of claim 1, wherein the adhesive layer is in a solid or semi-solid phase at room temperature, and the curable adhesive resin that is comprised in the adhesive layer is in a non-cured state.

13. A method of manufacturing the adhesive film of claim 1, comprising forming an adhesive layer by molding an adhesive composition in a film or sheet shape.

14. The method of claim 13, wherein the adhesive composition is manufactured by dissolving or distributing the moisture absorbent in a solvent; grinding the dissolved or distributed moisture absorbent; and then mixing the ground moisture absorbent with a curable adhesive resin.

15. An organic electronic device, comprising: a substrate; an organic electronic element formed on the substrate; and an encapsulant layer that is the adhesive film of claim 1 in a cured state and that covers an entire surface of the organic electronic element.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 and FIG. 2 are diagrams showing an exemplified adhesive film.

(2) FIG. 3 is a diagram showing an exemplified organic electronic device.

BEST MODES OF THE INVENTION

(3) Hereinafter, the adhesive composition, and the like will be described in further detail with reference to the following Examples and Comparative Examples, but the range of the present invention is not limited to the following Examples.

(4) Physical properties were evaluated using the following methods in Examples and Comparative Examples.

(5) 1. Evaluation of Adhesive Strength

(6) Two sheets of 0.7 T glass plates were disposed at right angles so as to be in a T shape. An adhesive layer with a size of 5 mm40 mm (widthlength) that was manufactured from Examples or Comparative Examples was disposed on a contact site between the above two plates, and hot-pressed under a vacuum with a pressure of 2 kgf at 80 C. for 2 minutes, and then cured again at 100 C. for 3 hours. Then, strength at the point at which the adhered glass specimen having the T shape was separated by pressing one end side of the T-shaped glass specimen with a constant pressure using a tensile tester was measured, and the measured value was defined as an adhesive strength.

(7) 2. Calcium Test

(8) Calcium (Ca) was deposited on a glass substrate in a size of 8 mm8 mm100 nm (widthlengththickness). Then, the adhesive layers manufactured from Examples and Comparative Examples were transferred to a cover glass, the cover glass was laminated on the calcium on the glass substrate to have a bezel of 3 mm, hot-pressed at 80 C. for 2 minutes using a vacuum press, and then cured at 100 C. for 3 hours to form an encapsulant layer and prepare a specimen. Then, while the specimen was maintained in a constant temperature and humidity chamber at 80 C. and 90% relative humidity, the time to change the end of the calcium deposition part to be transparent due to an oxidation was measured.

Example 1

(9) 70 g of CaO (available from Aldrich Co., Ltd.) as a moisture absorbent was added to methylethyl ketone at a concentration of 30 weight % to prepare a moisture absorbent solution. In addition, 18 g of nano clay (CLOISITE 93A, available from Southern Clay Products) as a filler was added to methylethyl ketone at a concentration of 30 weight % to prepare a filler solution. Then, each solution was introduced into a ball mill process and subjected to milling for about 24 hours. 200 g of a silane modified epoxy resin (KSR-177, available from KUKDO Chemical Co., Ltd.) and 150 g of a phenoxy resin (YP-50, available from Dongdo Chemicals Corporation) were added to a reactor at room temperature and diluted with methylethyl ketone to an appropriate concentration, nitrogen was replaced in the reactor, and then the solution was homogenized. The moisture absorbent and filler solution that went through the ball mill process were added to the homogenized solution, and 4 g of an imidazole curing agent (available from Shikoku Chemicals Corporation) was added, and stirred for 1 hour at a high speed. The stirred solution was filtered through a filter with a hole size of 20 m, and then the filtered solution was applied on a release film with a thickness of 50 m using a comma coater. The applied coating solution was dried in a drier at 120 C. for 5 minutes to form an adhesive layer that had a thickness of about 20 m and maintained a solid phase at room temperature. The manufactured adhesive layer was laminated to a release film with the same material as in the release film using a laminator to manufacture an adhesive film with the structure as shown in FIG. 2.

Example 2

(10) 53 g of CaO (available from Aldrich Co., Ltd.) as a moisture absorbent was added to methylethyl ketone at a concentration of 30 weight % to prepare a moisture absorbent solution. In addition, 10 g of nano clay (CLOISITE 93A, available from Southern Clay Products) as a filler was added to methylethyl ketone at a concentration of 30 weight % to prepare a filler solution. Each solution was introduced into a ball mill process and subject to milling for about 24 hours. In addition, 200 g of a silane modified epoxy resin (KSR-177, available from KUKDO Chemical Co., Ltd.) and 150 g of a phenoxy resin (YP-50, available from Dongdo Chemicals Corporation) were added to a reactor at room temperature and diluted with methylethyl ketone; nitrogen was replaced in the reactor, and then the prepared solution was homogenized. The milled moisture absorbent and filler solution were added to the homogenized solution, and 4 g of an imidazole curing agent (available from Shikoku Chemicals Corporation) was added and stirred for 1 hour at a high speed. Then, the stirred solution was filtered through a filter having a hole size of 20 m, and an adhesive film was obtained by the same method as in Example 1.

Comparative Example 1

(11) An adhesive film was manufactured using the same method as in Example 1, except that the moisture absorbent and the filler solution were not added.

Comparative Example 2

(12) An adhesive film was manufactured using the same method as in Comparative Example 1, except that as a moisture absorbent solution, a solution prepared by adding 70 g of CaO (available from Aldrich Co., Ltd.) to methylethyl ketone at a concentration of 30 weight % was milled in a ball mill process for about 24 hours, and then the solution was further added.

Comparative Example 3

(13) An adhesive film was manufactured using the same method as in Comparative Example 1, except that as a filler solution, the solution prepared by adding 35 g of nano clay (CLOISITE 93A, available from Southern Clay Products) to methylethyl ketone at a concentration of 30 weight % was milled in a ball mill process for about 24 hours, and then the solution was further added.

(14) The above-measured results were shown in the following Table 1:

(15) TABLE-US-00001 TABLE 1 Adhesive Strength (gf/cm.sup.2) Ca test results Example 1 600 400 hours Example 2 700 340 hours Comparative Example 1 350 24 hours Comparative Example 2 400 260 hours Comparative Example 3 700 120 hours

(16) As shown in the results of Table 1, Examples according to the present invention exhibited excellent adhesive strength to a glass plate. In addition, when deposited calcium was encapsulated, it was shown that it may effectively suppress an inflow of moisture, humidity, and the like from the outside.

(17) However, Comparative Example 1 without the moisture absorbent and filler did not have an adhesive strength and did not block moisture. Also, for Comparative Example 2 without the filler, it was shown that an adhesive strength was greatly decreased and a moisture-blocking property was not satisfactory. In addition, for Comparative Example 3 without the moisture absorbent, the moisture blocking property was greatly decreased.

EXPLANATION OF MARKS

(18) 1, 2: Adhesive Film

(19) 11: Adhesive Layer

(20) 12: First Film

(21) 21: Second Film

(22) 3: OED

(23) 31: Substrate

(24) 32: Organic Electronic Element

(25) 33: Encapsulant Layer

(26) 34: Cover Substrate