Pressure-sensitive adhesive composition

Abstract

The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive film including the same, and provides a pressure-sensitive adhesive composition and a pressure-sensitive adhesive film which may prevent damage to an element from moisture contained in the composition, ionic substances, and other foreign substances, and effectively block electrochemical corrosion, thereby improving a lifetime and durability of an organic electronic device.

Claims

1. A pressure-sensitive adhesive composition, comprising a pressure-sensitive adhesive resin and satisfying the following Equations 1 and 2:
X≤1000 ppm  [Equation 1]
Y≤250 ppm,  [Equation 2] wherein X in Equation 1 is an amount of volatile organic compounds which is measured by preparing a film with the composition, maintaining 50 mg of the film sample at 80° C. for 30 minutes, and using purge and trap-gas chromatography/mass spectrometry, and Y in Equation 2 is an amount of ionic substances contained in the composition, which is obtained by preparing a film with the composition, and measuring 50 mg of the film sample according to ASTM D 7359:2008, wherein the pressure-sensitive adhesive composition further comprises a tackifier resin having an acid value of 1 KOH mg/g or less.

2. The pressure-sensitive adhesive composition of claim 1, wherein a moisture content of a film sample formed of the pressure-sensitive adhesive composition is 0.01 wt % or more, and the moisture content of the film sample is measured according to ASTM D3451-06 (2012) after preparing a film with the pressure-sensitive adhesive composition, and maintaining 50 mg of the film sample under conditions of 25° C. and a relative humidity of 50% for 24 hours.

3. The pressure-sensitive adhesive composition of claim 1, wherein the ionic substance is halogen ions.

4. The pressure-sensitive adhesive composition of claim 1, wherein the pressure-sensitive adhesive resin is a styrene-based resin, a polyolefin-based resin, a thermoplastic elastomer, a polyoxyalkylene-based resin, a polyester-based resin, a polyvinyl chloride-based resin, a polycarbonate-based resin, a polyphenylene sulfide-based resin, a hydrocarbon mixture, a polyamide-based resin, an acrylate-based resin, an epoxy-based resin, a silicone-based resin, a fluorine-based resin, or a mixture thereof.

5. The pressure-sensitive adhesive composition of claim 1, wherein the pressure-sensitive adhesive resin has a halogen ion content of less than 300 ppm when measured according to ASTM D 7359:2008.

6. The pressure-sensitive adhesive composition of claim 1, further comprising an organic solvent of which a boiling point is 100° C. or less.

7. The pressure-sensitive adhesive composition of claim 1, further comprising a photoinitiatior.

8. The pressure-sensitive adhesive composition of claim 7, wherein the photoinitiatior is a photo-radical initiator.

9. The pressure-sensitive adhesive composition of claim 1, wherein the tackifier resin is included at 5 to 100 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive resin.

10. The pressure-sensitive adhesive composition of claim 1, further comprising a silane coupling agent at less than 2 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive resin.

11. A pressure-sensitive adhesive film comprising the pressure-sensitive adhesive composition of claim 1.

12. An organic electronic device, comprising: a substrate; an organic electronic element formed on the substrate; and the pressure-sensitive adhesive film of claim 11 encapsulating the organic electronic element.

13. The organic electronic device of claim 12, wherein the organic electronic element is an organic light emitting diode.

14. A method of preparing an organic electronic device, comprising applying the pressure-sensitive adhesive film of claim 11 on a substrate on which an organic electronic element is formed to cover the organic electronic element.

15. The pressure-sensitive adhesive composition of claim 1, further comprising a polyfunctional acrylate.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The drawing is a cross-sectional view illustrating an encapsulating product of an organic electronic device according to an embodiment of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

(2) 12: adhesive film 21: substrate 22: cover substrate 23: organic electronic element

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

(3) Hereinafter, the present invention will be described in detail in conjunction with exemplary examples according to the present invention and comparative examples not according to the present invention, but the scope of the present invention is not intended to be limited to the examples described below, and it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.

Example 1

(4) 90 g of polyisobutylene (Mw 340 k, Cl 10 ppm>), 10 g of a tackifier resin (H-DCPD-based, s.p. 125° C., volatile 0.5 wt %>), 6 g of an acrylate (trimethylolpropane triacrylate), and 0.5 g of a photoinitiatior (2,2-dimethoxy-1,2-diphenylethan-1-one) were added with toluene such that solid fractions were generated at 20%, and stirred to prepare a coating solution.

(5) The prepared solution was applied onto a release surface of a release PET film using a comma coater, and dried at 100° C. for 30 minutes, and then a pressure-sensitive adhesive film having a thickness of 50 μm was formed.

Example 2

(6) A pressure-sensitive adhesive film was prepared in the same method as Example 1 except that a content of the photoinitiatior (2,2-dimethoxy-1,2-diphenylethan-1-one) was changed to 0.2 g, and the drying time was set to 10 minutes.

Comparative Example 1

(7) A pressure-sensitive adhesive film was prepared in the same method as Example 1 except that a tackifier resin (SU90; Kolon Industries, Inc.) in which volatile organic compounds (VOCs) were detected through purge and trap-gas chromatography/mass spectrometry at 2 wt % or more during drying at 150° C. for 1 hour were used, and the drying time was set to 10 minutes.

Comparative Example 2

(8) A pressure-sensitive adhesive film was prepared in the same method as Example 1 except that a tackifier resin product having an acid value of 5 KOH mg/g (REAGEM 5110; Parchem fine & specialty chemicals) was used, and the drying time was set to 10 minutes.

Comparative Example 3

(9) A pressure-sensitive adhesive film was prepared in the same method as Example 1 except that a butyl rubber having a content of chlorine ions of 300 ppm or more as measured according to ASTM D 7359:2008 was used, and the drying time was set to 10 minutes.

Experimental Example 1: Total Volatile Organic Compounds (VOC) Measurement

(10) Measurement device: Purge & Trap sampler-GC/MSD system (P & T: JAI JTD-505III, GC/MS: Agilent 7890B/5977A)

(11) Samples coated with the films were weighed to approximate 50 mg, passed through purge and trap at 80° C. for 30 minutes, and a total amount of VOCs was measured through GC-MS. The measured volatilization amount was quantified using toluene as a standard reagent.

Experimental Example 2: Ionic Substance (Trace Element) and Acid Value Measurement

(12) Preprocessing of the samples weighed to about 50 mg and having films applied thereto was performed according to EN 50267-2-1 & 502672-2, a trace element was measured according to ASTM D 7395:2008, and an acid value was measured according to a method of ASTM D 974.

(13) Evaluation Method: Dark Spot

(14) An element available for a lighting test was deposited on a glass substrate. After the pressure-sensitive adhesive film on a coated sheet was heat laminated on the glass substrate for encapsulating, the film was vacuum-pressed for 3 minutes at a pressure of 5 kg/cm.sup.2 while being heated at 80° C. on the substrate. The pressed sample was thermally cured at 100° C. for 2 hours in an oven. The thermally cured sample was observed under conditions of a constant temperature and humidity of 85° C. and 85% RH, and checked for dark spots. Through an observation for 300 hours, it was checked whether or not dark spots were generated on the sample.

(15) Evaluation Method: Wire Corrosion, Bubble Formation and Damage to TFT

(16) An element was deposited on a glass substrate. After the coated adhesive film on a sheet was heat laminated on the glass substrate for encapsulating, the film was vacuum-pressed for 3 minutes at a pressure of 5 kg/cm.sup.2 while being heated at 80° C. on the substrate. The pressed sample was thermally cured at 100° C. for 2 hours in an oven. After applying the pressure-sensitive adhesive film on the organic electronic element as described above, the film was checked with the naked eye for wire corrosion, bubbles, and damage to the TFT.

(17) TABLE-US-00001 TABLE 1 Ionic VOCs substances Etc. (wire corrosion (ppm) (ppm) Dark spot and bubbles) Example 1 89 59 None Good Example 2 59 79 None Good Comparative 1400 166 None Bubbles formed on Example 1 pressing/curing Comparative 230 269 Generated Wire corrosion Example 2 Comparative 156 341 Generated Damage to TFT Example 3

(18) In Example 1 in which the resin having a low content of halogen ions, and a tackifier resin having a low amount of VOCs and low acid value were used, VOCs and ionic substances were both effectively suppressed. On the other hand, in Comparative Example 1 using the tackifier resin in which a great amount of VOCs was detected, or in Comparative Example 2 using the tackifier resin having an acid value of 5 KOH mg/g, a great amount of VOCs or ionic substances was generated, resulting in generation of bubbles or wire corrosion. Further, in Comparative Example 3 in which the butyl rubber having a Cl content of 300 ppm or more was used, a great amount of ionic substances was generated, and thereby damage to the TFT was determined.