U.S. patent application number 16/119600 was filed with the patent office on 2019-01-17 for encapsulation film and organic electronic device comprising the same.
The applicant listed for this patent is LG CHEM, LTD.. Invention is credited to Ban Seok CHOI, Hyun Suk KIM, Seung Min LEE, Jung Ok MOON, Se Woo YANG, Hyun Jee YOO.
Application Number | 20190019987 16/119600 |
Document ID | / |
Family ID | 54059376 |
Filed Date | 2019-01-17 |
United States Patent
Application |
20190019987 |
Kind Code |
A1 |
CHOI; Ban Seok ; et
al. |
January 17, 2019 |
ENCAPSULATION FILM AND ORGANIC ELECTRONIC DEVICE COMPRISING THE
SAME
Abstract
Provided are an encapsulation film, an organic electronic device
comprising the same, and a method of manufacturing the organic
electronic device. When the organic electronic device is
encapsulated using the encapsulation film, an excellent moisture
barrier property may be realized, and as reflection or scattering
of light is prevented by absorbing and blocking internal or
external light, external defects of the organic electronic device
may be prevented.
Inventors: |
CHOI; Ban Seok; (Daejeon,
KR) ; YOO; Hyun Jee; (Daejeon, KR) ; KIM; Hyun
Suk; (Daejeon, KR) ; LEE; Seung Min; (Daejeon,
KR) ; MOON; Jung Ok; (Daejeon, KR) ; YANG; Se
Woo; (Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD. |
Seoul |
|
KR |
|
|
Family ID: |
54059376 |
Appl. No.: |
16/119600 |
Filed: |
August 31, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15116167 |
Aug 2, 2016 |
10096797 |
|
|
PCT/KR2015/001659 |
Feb 17, 2015 |
|
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16119600 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08J 5/18 20130101; B32B
2255/10 20130101; B32B 2255/20 20130101; H01L 51/5234 20130101;
H01L 51/5253 20130101; B32B 17/00 20130101; B32B 27/322 20130101;
H01L 2251/301 20130101; H01L 2251/5392 20130101; B32B 27/08
20130101; C08J 2471/12 20130101; B32B 7/06 20130101; B32B 2307/302
20130101; H01L 51/5243 20130101; B32B 27/32 20130101; B32B 27/36
20130101; B32B 15/095 20130101; H01L 51/529 20130101; B32B 15/082
20130101; H01L 51/5012 20130101; B32B 2307/40 20130101; C08J
2463/04 20130101; H01L 51/56 20130101; B32B 15/085 20130101; B32B
2250/03 20130101; H01L 51/5284 20130101; B32B 27/306 20130101; B32B
15/20 20130101; H01L 51/5259 20130101; B32B 27/304 20130101; C08L
63/00 20130101; H01L 51/0035 20130101; B32B 2255/205 20130101; C08J
2363/00 20130101; B32B 2255/26 20130101; B32B 2307/7246 20130101;
B32B 27/281 20130101; B32B 27/308 20130101; H01L 51/5218 20130101;
B32B 2307/416 20130101; B32B 2457/206 20130101; B32B 27/40
20130101; B32B 15/09 20130101; B32B 2307/748 20130101; H01L
2251/303 20130101 |
International
Class: |
H01L 51/52 20060101
H01L051/52; C08J 5/18 20060101 C08J005/18; C08L 63/00 20060101
C08L063/00; H01L 51/00 20060101 H01L051/00; H01L 51/50 20060101
H01L051/50; H01L 51/56 20060101 H01L051/56 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 18, 2014 |
KR |
10-2014-0018669 |
Jun 13, 2014 |
KR |
10-2014-0071989 |
Sep 29, 2014 |
KR |
10-2014-0130495 |
Claims
1. An encapsulation film for an organic electronic element,
comprising: a light absorbing region comprising an encapsulation
resin and a light absorbing material, and having a surface
resistance of 10.sup.11 .OMEGA./cm.sup.2 or more.
2. The film according to claim 1, wherein the light absorbing
region is formed in at least one outer peripheral part of the
encapsulation film.
3. The film according to claim 1, wherein the light absorbing
region is formed in an entire area of the encapsulation film.
4. The film according to claim 1, which has a haze of 40% to
90%.
5. The film according to claim 1, wherein the encapsulation resin
comprises an acrylic resin, an epoxy resin, a silicone resin, a
fluorine resin, a styrene resin, a polyolefin resin, a
thermoplastic elastomer, a polyoxyalkylene resin, a polyester
resin, a polyvinylchloride resin, a polycarbonate resin, a
polyphenylenesulfide resin, a polyamide resin or a mixture
thereof.
6. The film according to claim 1, wherein the encapsulation resin
comprises a curable resin.
7. The film according to claim 6, wherein the curable resin is a
heat-curable resin.
8. The film according to claim 6, wherein the curable resin
comprises at least one curable functional group selected from a
glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl
group, an amide group, an epoxide group, a cyclic ether group, a
sulfide group, an acetal group, and a lactone group.
9. The film according to claim 6, wherein the curable resin is an
epoxy resin comprising a cyclic structure in a molecular
structure.
10. The film according to claim 6, wherein the curable resin is a
silane-modified epoxy resin.
11. The film according to claim 1, wherein the light absorbing
material is a non-conductive material.
12. The film according to claim 1, wherein the light absorbing
material is at least one selected from the group consisting of
carbon black, carbon nanotube, fluorene, a phthalocyanine
derivative, a porphyrin derivative, and a triphenylamine
derivative.
13. The film according to claim 1, wherein the light absorbing
material is comprised at 0.01 to 50 parts by weight with respect to
100 parts by weight of the encapsulation resin.
14. The film according to claim 1, further comprising a moisture
absorbent.
15. The film according to claim 14, wherein the moisture absorbent
is at least one selected from the group consisting of
P.sub.2O.sub.5, Li.sub.2O, Na.sub.2O, BaO, CaO, MgO,
Li.sub.2SO.sub.4, Na.sub.2SO.sub.4, CaSO.sub.4, MgSO.sub.4,
CoSO.sub.4, Ga.sub.2(SO.sub.4).sub.3, Ti(SO.sub.4).sub.2,
NiSO.sub.4, CaCl.sub.2, MgCl.sub.2, SrCl.sub.2, YCl.sub.3,
CuCl.sub.2, CsF, TaF.sub.5, NbF.sub.5, LiBr, CaBr.sub.2,
CeBr.sub.3, SeBr.sub.4, VBr.sub.3, MgBr.sub.2, BaI.sub.2,
MgI.sub.2, Ba(ClO.sub.4).sub.2 and Mg(ClO.sub.4).sub.2.
16. The film according to claim 1, comprising: a light absorbing
layer comprising the light absorbing region; and a moisture barrier
layer.
17. The film according to claim 16, wherein the moisture barrier
layer has a water vapor transmission rate (WVTR) of 50 g/m.sup.2day
or less.
18. The film according to claim 1, further comprising: a metal
layer.
19. The film according to claim 18, wherein the metal layer has a
thermal conductivity of 50 W/mK or more.
20. The film according to claim 18, wherein the metal layer has a
reflectance of 15 to 90% in Specular Component Included SCI
measurement, or 15 to 80% in Specular Component Excluded SCE
measurement.
21. An organic electronic device, comprising: a substrate; an
organic electronic element comprising a transparent electrode layer
present on the substrate, an organic layer present on the
transparent electrode layer and comprising at least an emitting
layer, and a reflective electrode layer present on the organic
layer; and an encapsulation film encapsulating an entire surface of
the organic electronic element, and comprising a light absorbing
region having a surface resistance of 10.sup.11 .OMEGA./cm.sup.2 or
more.
22. The organic electronic device according to claim 21, wherein
the light absorbing region is formed in at least one outer
peripheral part of the encapsulation film.
23. The organic electronic device according to claim 21, wherein
the light absorbing region is formed in an entire area of the
encapsulation film.
24. The organic electronic device according to claim 21, wherein
the encapsulation film further comprises a metal layer.
25. A method of manufacturing an organic electronic device,
comprising: forming an organic electronic element comprising a
transparent electrode layer, an organic layer present on the
transparent electrode layer and comprising at least an emitting
layer and a reflective electrode layer present on the organic
layer, on a substrate; and applying the encapsulation film of claim
1 to the substrate on which the organic electronic element is
formed to encapsulate an entire surface of the organic electronic
element.
Description
BACKGROUND
1. Field of the Invention
[0001] The present invention relates to an encapsulation film, an
organic electronic device (OED) comprising the same, and a method
of manufacturing the OED.
2. Discussion of Related Art
[0002] An OED refers to a device including an organic material
layer generating an exchange of charges using holes and electrons.
Examples of the OEDs may include a photovoltaic device, a
rectifier, a transmitter, and an organic light emitting diode
(OLED).
[0003] In one exemplary embodiment, an OLED has less power
consumption and a higher response speed, and is advantageous in
forming a thinner display device or light than a conventional light
source. Since the OLED also has excellent space utilization, the
OLED is expected to be applied in various fields including all
types of portable devices, monitors, notebook computers and
TVs.
[0004] To expand commercialization and use of the OLED, the most
important problem is durability. Organic materials and metal
electrodes included in the OLED are very easily oxidized by
external factors such as moisture. In addition, when a display is
realized by applying the OLED, a part in which an electrical
connection is deposited on a outer peripheral part of the display,
and a part in which an electrical connection is not deposited on a
outer peripheral part of the display are included. In the
non-deposited part, internal or external light may be reflected or
scattered, and some parts seen bright from an outside cause a
external defect.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to providing an
encapsulation film which has an excellent moisture barrier property
and is capable of preventing a external defect of an OED by
absorbing and blocking internal or external light to prevent
reflection or scattering of the light, an OED having the same, and
a method of manufacturing an OED.
[0006] Hereinafter, exemplary embodiments of the present invention
will be described in further detail with respect to the
accompanying drawings. In addition, to explain the present
invention, related known detail description for a common function
or configuration is omitted. In addition, the accompanying drawings
are provided to help in understanding the present invention, and to
more clearly explain the present invention, parts not relating to
the description are omitted. To clearly express several layers and
regions in the drawing, thicknesses or sizes are exaggerated. The
scope of the present invention is not limited to thicknesses, sizes
and ratios represented in the drawings.
[0007] In one aspect, the present invention provides a film for
encapsulating an organic electronic element. The encapsulation film
of the present invention may be applied to encapsulate or capsulate
an entire area of the organic electronic element such as an
OLED.
[0008] The exemplary encapsulation film may include a light
absorbing region. In one example, the light absorbing region may
comprise an encapsulation resin and a light absorbing material. In
the present invention, the light absorbing region may mean a region
having a surface resistance of 10.sup.11 .OMEGA./cm.sup.2 or more
in the encapsulation film. In another exemplary embodiment of the
present invention, the encapsulation film may include a light
absorbing layer including a light absorbing region, which comprises
an encapsulation resin and a light absorbing material and has a
surface resistance of 10.sup.11 .OMEGA./cm.sup.2 or more; and a
moisture barrier layer. In another aspect, the present invention
provides an OED, which includes a substrate, an organic electronic
element present on the substrate and an encapsulation film having
the light absorbing region attached to an entire surface of the
organic electronic element. Meanwhile, the light absorbing region
may mean a region including a light absorbing material in a
thickness direction when the encapsulation film is formed in two or
more layers. That is, in this case, a part of the moisture barrier
layer may be defined as the light absorbing region, in addition to
a part of the light absorbing layer.
[0009] The term "OED" used herein means a product or device having
an element including an organic material layer generating an
exchange of charges using holes and electrons between a pair of
electrodes facing each other, and as an example, a photovoltaic
device, a rectifier, a transmitter and an OLED may be included, but
the present invention is not limited thereto. In one example of the
present invention, the OED may be an OLED.
[0010] The term "light absorbing layer" or "moisture barrier layer"
used herein may be an adhesive layer, a pressure-sensitive adhesive
layer or a curable pressure-sensitive adhesive layer, which forms
the encapsulation film. Accordingly, when needed, the encapsulation
film and the light absorbing layer and/or the moisture barrier
layer may be mutually used with the same meaning. Here, the term
"curable pressure-sensitive adhesive layer" used herein means a
type of adhesive layer which is maintained in a solid or semi-solid
state at room temperature to attach an adherend without bubbles due
to flowability generated when heated and tightly fix the adherend
using an adhesive after solidifying. In one exemplary embodiment,
the "light absorbing layer" means a layer including the light
absorbing region. In addition, in one exemplary embodiment, the
"moisture barrier layer" means a layer having a water vapor
transmission rate (WVTR) of 50 g/m.sup.2day or less, preferably 30
g/m.sup.2day or less, more preferably 20 g/m.sup.2day or less, and
further more preferably, 15 g/m.sup.2day or less. In the present
invention, the WVTR is a rate measured with respect to a thickness
direction of a crosslinked product or cured product at 38.degree.
C. and a relative humidity of 100% after an encapsulation resin
which will be described below is crosslinked or cured, and a
crosslinked product or a cured product is formed in a film shape
having a thickness of 80 .mu.m. In addition, the WVTR is measured
according to ASTM F1249. As the WVTR is controlled in the above
range, permeation of moisture, vapor or oxygen into an
encapsulation product of the OED may be effectively inhibited. In
the present invention, as a level of the WVTR of the encapsulation
film is lower, an encapsulation structure exhibits an excellent
performance. The lower limit of the WVTR may be, but is not
particularly limited to, for example, 0, 1 or 3 g/m.sup.2day. The
moisture barrier layer may include an encapsulation resin, and
further include a moisture absorbent. Components constituting the
moisture barrier layer, for example, the encapsulation resin or the
moisture absorbent, may be equal to or different from the
components constituting the light absorbing layer.
[0011] The term "encapsulation composition" used herein is a
component constituting the light absorbing layer or moisture
barrier layer of the encapsulation film. The encapsulation
composition may include an encapsulation resin, a light absorbing
material, a moisture absorbent, or other additives. In the light
absorbing layer and the moisture barrier layer of the encapsulation
film, types and contents of the components of the encapsulation
composition, excluding the light absorbing material, for example,
the encapsulation resin, the moisture absorbent, other additives or
a filler may be the same as or different from each other. Unless
particularly cited otherwise, description on the encapsulation
composition which will be described below corresponds to all of the
light absorbing layer and the moisture barrier layer of the
encapsulation film.
[0012] In one example, a structure of the encapsulation film is not
particularly limited. The encapsulation film has a single layer
structure or a multilayer structure including at least two layers.
In one example, when the encapsulation film has a single layer
structure, the above-described light absorbing layer may be
included, and when the encapsulation film has a multilayer
structure having at least two layers, the above-described light
absorbing layer and the moisture barrier layer may be included.
[0013] FIG. 1 is a cross-sectional view of an encapsulation film
according to the present invention. An exemplary encapsulation film
1 may include a light absorbing layer 2. In addition, as shown in
FIGS. 2 to 4, the encapsulation film 1 may have a multilayer
structure having at least two layers, and in this case, the
encapsulation film 1 may include at least one light absorbing layer
2. In one example, when the encapsulation film 1 has a single layer
structure as shown in FIG. 1, the light absorbing layer 2 may be
included. Specifically, when the encapsulation film 1 includes a
single layer structure, as shown in FIG. 1(a), the light absorbing
layer may include a light absorbing material 3, or as shown in FIG.
1(b), the light absorbing layer may include a light absorbing
material 3 and a moisture absorbent 5. In addition, as shown in
FIG. 2, when the encapsulation film 1 has a bilayer structure, a
light absorbing layer 2 and a moisture barrier layer 4 may be
included. When the encapsulation film has a multilayer structure, a
sequence of stacking a light absorbing layer and a moisture barrier
layer is not particularly limited. In addition, when the
encapsulation film has a multilayer structure including at least
three layers, the moisture barrier layer may have a multilayer
structure. When the moisture barrier layer has a multilayer
structure, the light absorbing layer may be disposed between the at
least two moisture barrier layers, or may be formed on one or both
surfaces of a structure in which at least two moisture barrier
layers are stacked. FIG. 3 shows that the light absorbing layer 2
is disposed between two moisture barrier layers 4 and 6, and one
(the moisture barrier layer 6) of the two moisture barrier layers
does not include a moisture absorbent 5 or includes a small amount
of the moisture absorbent 5 in consideration of being encapsulated
in contact with an organic electronic element. FIG. 4 shows that
the light absorbing layer 2 is formed on one surface of a structure
in which the two moisture barrier layers 4 and 6 are stacked, and
one (the moisture barrier layer 6) of the two moisture barrier
layers 4 and 6 does not include a moisture absorbent 5 or includes
a small amount of the moisture absorbent 5 in consideration of
being encapsulated in contact with an organic electronic element.
In addition, the encapsulation film may include at least two light
absorbing layers. In this case, two light absorbing layers may be
continuously stacked, and the moisture barrier layer may be
included between the two light absorbing layers.
[0014] In an exemplary embodiment of the present invention, the
encapsulation film may include a light absorbing region comprising
an encapsulation resin and a light absorbing material as described
above, and having a surface resistance of 10.sup.11
.OMEGA./cm.sup.2 or more. In the encapsulation film, a non-light
absorbing region, not the light absorbing region, may consist of
the same components as those constituting the light absorbing
region, except that a light absorbing material is not included.
[0015] When a display is realized using an OLED, a part of the
display in which an electrical connection is deposited on a side
surface thereof, and a part of the display in which an electrical
connection is not deposited are included. Accordingly, in the
non-deposited part, external light may be reflected or scattered,
and here, the light absorbing region of the encapsulation film
serves to absorb and block reflected or scattered light.
[0016] A part of the encapsulation film in which the light
absorbing region is formed is not particularly limited, but for
example, the light absorbing region may be formed in at least one
outer peripheral part of the encapsulation film. The term "outer
peripheral part" used herein means an edge. That is, the outer
peripheral part of the film may mean an edge of a circumference of
the film. In another exemplary embodiment, the light absorbing
region may be formed in an entire area of the encapsulation film.
That is, when the encapsulation film is observed in a plan view,
the entire area of the encapsulation film may have a surface
resistance of 10.sup.11 .OMEGA./cm.sup.2 or more, or only at least
one outer peripheral part of the encapsulation film may have a
surface resistance of 10.sup.11 .OMEGA./cm.sup.2 or more. In the
present invention, when the film has a single layer structure, the
surface resistance may be a surface resistance measured with
respect to the light absorbing region of the single layer. In
addition, when the film has a multilayer structure, the surface
resistance may be a surface resistance measured in the multilayer
stacked structure including at least one light absorbing layer
and/or at least one moisture barrier layer. For example, the
above-described light absorbing region may be a region including a
light absorbing material, and having a surface resistance measured
with respect to a surface of the encapsulation film in contact with
the organic electronic element of 10.sup.11 .OMEGA./cm.sup.2 or
more. In addition, in one example, the upper limit of the surface
resistance of the encapsulation film according to the present
invention may be, but is not particularly limited to, for example,
10.sup.18 .OMEGA./cm.sup.2. The surface resistance may be, for
example, 10.sup.11 .OMEGA./cm.sup.2 or more, 10.sup.12
.OMEGA./cm.sup.2 or more, 10.sup.13 .OMEGA./cm.sup.2 or more,
10.sup.14 .OMEGA./cm.sup.2 or more or 10.sup.15 .OMEGA./cm.sup.2 or
more. As the range of the surface resistance is measured and
controlled, conductivity of the encapsulation film may be adjusted
in a suitable range. When the encapsulation film including a light
absorbing material is applied in encapsulation of the OED, when the
film has electric conductivity, abnormal driving of the OED is
induced. Accordingly, as a unit for adjusting conductivity of the
encapsulation film, the surface resistance may be measured to
control. The surface resistance may be measured by a conventional
method known in the art. For example, the surface resistance may be
measured according to a standard test method using a surface
resistance meter, MCP-HT450, manufactured by Mitsubishi Chemical
Corporation. In one example, for the measurement of the surface
resistance, a surface resistance of a light absorbing region of the
encapsulation film from which a releasing film is removed is
measured, and a value of the surface resistance is measured after
applying a voltage of 500 V for 1 minute at 23.degree. C. and 50%
R.H.
[0017] FIGS. 5 to 8 are plan views of an encapsulation film of the
present invention.
[0018] As described above, in the encapsulation film, as shown in
FIG. 5, a light absorbing region may be formed in an entire area of
the encapsulation film, but the present invention is not limited.
That is, when the encapsulation film is observed in the plan view,
as shown in FIGS. 6 to 8, the light absorbing region may be formed
in at least one outer peripheral part. That is, when a region of
the encapsulation film 1 in which a light absorbing material is
included is referred to as a light absorbing region or a first
region 10, and a region in which a light absorbing material is not
included is referred to as a non-light absorbing region or a second
region 11, the entire area of the encapsulation film may be the
first region 10. Alternatively, only one outer peripheral part of
the encapsulation film 1 may be the first region 10. Here, a
thickness of the outer peripheral part may be suitably adjusted.
That is, as shown in FIG. 6, one of four outer peripheral parts is
the first region 10, and the others may be the second regions 11.
Alternatively, as shown in FIG. 8, all four outer peripheral parts
may be the first regions 10. Here, a thickness of each outer
peripheral part may be suitably adjusted according to a field and
application to which the encapsulation film is applied by those of
ordinary skill in the art. In addition, the term "first region 10"
used herein may be used with the same meaning as the
above-described light absorbing region.
[0019] In an exemplary embodiment of the present invention, the
encapsulation film may have a haze of 40 to 90%, 55 to 85%, or 60
to 80%. The haze may be measured by a conventional method known in
the art, and when the film is formed in a single layer structure,
the haze may be measured to an entire area of the film, and when
the film is formed in a multilayer structure, the haze may be
measured to an entire area of the film having a multilayer stacked
structure. For example, the haze may be measured according to a JIS
K7105 standard test method using a haze meter. The haze value may
be controlled in a suitable range according to a desired use of the
encapsulation film by those of ordinary skill in the art. In
addition, the haze value may be controlled in the above-described
specific range by a method of adjusting a content or diameter of a
moisture absorbent or filler which will be described below. As the
haze vale is controlled to be maintained at 40% or more, it can be
confirmed that the moisture barrier performance is maintained
without a reaction of the moisture absorbent with moisture in the
air in the process of manufacturing a film.
[0020] In one example, the light absorbing region of the
encapsulation film may have a light transmittance of 15% or less
with respect to a visible light region. In the present invention,
when the film is formed in a single layer structure, the light
transmittance may be a light transmittance with respect to a
visible light region, which is measured in a thickness direction of
the light absorbing region. In addition, when the film is formed in
a multilayer structure, the light transmittance may be a light
transmittance measured in the multilayer stacked structure
including at least one light absorbing layer and/or at least one
moisture barrier layer. For example, when the encapsulation film
according to the present invention is observed in the plan view,
the above-described light absorbing region may be a region having a
light transmittance of 15% or less in a thickness direction of the
film having a stacked structure. In one example, the lower limit of
the light transmittance in the visible light region according to
the present invention may be, but is not particularly limited to,
0%. The light transmittance may be, for example, 0.2 to 15%, 0.5%
to 15%, 1% to 15%. 1% to 14%, 1% to 13%, 2% to 12%, 3% to 11%, or
3% to 10%. Particularly, when the display is realized using an
OLED, a part of the display in which an electrical connection is
deposited on a side surface, and a part in which an electrical
connection is not deposited are included. Accordingly, in the
non-deposited part, external light may be reflected or scattered,
and here, the encapsulation film serves to absorb and block
reflected or scattered light. In one example, the light
transmittance may be measured at 550 nm using an UV-Vis
spectrometer.
[0021] In the present invention, an encapsulation composition
constituting the light absorbing layer or moisture barrier layer
may be formed of a known material. For example, as described above,
the encapsulation composition constituting the light absorbing
layer may include the encapsulation resin and the light absorbing
material. In addition, a type or content of the light absorbing
material may be adjusted for the light absorbing region of the
encapsulation film to have the above range of surface resistance or
light transmittance by those of ordinary skill in the art.
[0022] In one exemplary embodiment of the present invention, a type
of the encapsulation resin constituting the encapsulation
composition is not particularly limited. The encapsulation resin
described herein may be included in all of the light absorbing
layer and the moisture barrier layer.
[0023] In one example, the encapsulation resin may be solid or
semi-solid, preferably solid, at room temperature. Here, when the
resin is solid or semi-solid at room temperature, the resin may not
have flowability at room temperature. For example, the "solid or
semi-solid at room temperature" used herein may mean that a
viscosity of a target at room temperature is approximately 10.sup.6
poise or more or approximately 10.sup.7 poise or more. Here, the
viscosity is measured at a strain of 5% and a frequency of 1 Hz
using an Advanced Rheometric Expansion System (ARES).
[0024] When the encapsulation resin is solid or semi-solid at room
temperature, it can be maintained in a film or sheet shape in an
uncured state. Accordingly, in encapsulation or capsulation of the
organic electronic element using the encapsulation film, physical
or chemical damage applied to the element may be prevented, and the
process may be smoothly performed. In addition, the addition of
bubbles during the encapsulation or capsulation of the organic
electronic element or the decrease in a life span of the element
may be prevented. The upper limit of the viscosity of the
encapsulation resin is not particularly limited, and may be
controlled in a range of approximately 10.sup.9 poise or less, for
example, in consideration of processability.
[0025] For example, the encapsulation resin may be an acrylic
resin, an epoxy resin, a silicone resin, a fluorine resin, a
styrene resin, a polyolefin resin, a thermoplastic elastomer, a
polyoxyalkylene resin, a polyester resin, a polyvinylchloride
resin, a polycarbonate resin, a polyphenylenesulfide resin, a
polyamide resin or a mixture thereof.
[0026] Here, the styrene resin may be, for example, a
styrene-ethylene-butadiene-styrene block copolymer (SEBS), a
styrene-isoprene-styrene block copolymer (SIS), an
acrylonitrile-butadiene-styrene block copolymer (ABS), an
acrylonitrile-styrene-acrylate block copolymer (ASA), a
styrene-butadiene-styrene block copolymer (SBS), a styrene-based
homopolymer or a mixture thereof. The olefin resin may be, for
example, a high density polyethylene-based resin, low density
polyethylene-based resin, polypropylene-based resin or a mixture
thereof. The thermoplastic elastomer may be, for example, an
ester-based thermoplastic elastomer, an olefin-based thermoplastic
elastomer or a mixture thereof. Here, as the olefin-based
thermoplastic elastomer, a polybutadiene resin or a polyisobutylene
resin may be used. As the polyoxyalkylene resin, for example, a
polyoxymethylene-based resin, polyoxyethylene-based resin or a
mixture thereof may be used. As the polyester resin, for example, a
polyethylene terephthalate-based resin, polybutylene
terephthalate-based resin or a mixture thereof may be used. As the
polyvinylchloride resin, for example, polyvinylidene chloride may
be used. In addition, a mixture of a hydrocarbon resin, for
example, hexatriacotane or paraffin may be used. As the polyamide
resin, for example, nylon may be used. As the acrylate resin, for
example, polybutyl(meth)acrylate may be used. As the silicone
resin, for example, polydimethylsiloxane may be used. In addition,
as the fluorine resin, a polytrifluoroethylene resin, a
polytetrafluoroethylene resin, polychlorotrifluoroethylene resin,
polyhexafluoropropylene resin, polyvinylidene fluoride, polyvinyl
fluoride, polyethylenepropylene fluoride or a mixture thereof may
be used.
[0027] The above-listed resin may be grafted to, for example,
maleic anhydride, polymerized with another one of the listed resins
or a monomer for preparing a resin, or modified by a different
compound. As an example of the different compound, a
carboxyl-terminated butadiene-acrylonitrile copolymer may be
used.
[0028] In one example, the encapsulation resin of the encapsulation
composition may include a polyisobutylene-based resin. The
polyisobutylene-based resin may have a low WVTR and a low surface
energy due to hydrophobicity. Specifically, as the
polyisobutylene-based resin, for example, a homopolymer of an
isobutylene monomer; or a copolymer prepared by copolymerizing
another monomer polymerized with an isobutylene monomer. Here, the
another monomer polymerized with an isobutylene monomer may be, for
example, 1-butene, 2-butene, isoprene or butadiene. In one example,
the copolymer may be butyl rubber.
[0029] As a component for the encapsulation resin, a base resin
having a weight average molecular weight (Mw) capable of being
molded in a film shape may be used. In one example, a range of the
weight average molecular weight capable of being molded in a film
shape may be approximately 100,000 to 2,000,000, 100,000 to
1,500,000, or 100,000 to 1,000,000. The term "weight average
molecular weight" used herein means a conversion value with respect
to standard polystyrene measured by gel permeation chromatography
(GPC).
[0030] In addition, as the component for the encapsulation resin,
one or at least two of the above components may be used. When at
least two components are used, at least two different types of
resins, at least two resins having different weight average
molecular weights, or at least two different types of resins having
different weight average molecular weights may be used.
[0031] In still another exemplary embodiment, the encapsulation
resin according to the present invention may be a curable resin. A
specific type of the curable resin which can be used in the present
invention is not particularly limited, and for example, various
heat-curable or photocurable resins known in the art may be used.
The term "heat-curable resin" means a resin which can be cured
through a process of suitably applying heat or an aging process,
and the term "photocurable resin" means a resin which can be cured
by radiation of electromagnetic waves. In addition, the curable
resin may be a dual curable resin including all heat curing and
photocuring characteristics. In one example, the curable resin of
the present invention may be a heat-curable resin, not a
photocurable resin, in consideration that the encapsulation
composition is composed of the curable resin with a light absorbing
material which will be described below, but the present invention
is not limited thereto.
[0032] A specific type of the curable resin in the present
invention may be any type having the above-described
characteristics without particular limitation. For example, the
curable resin may have an adhesive characteristic by curing, and
may be a resin including at least one heat-curable functional group
such as a glycidyl group, an isocyanate group, a hydroxyl group, a
carboxyl group or an amide group, or a resin including at least one
functional group which can be cured by radiation of electromagnetic
waves such as an epoxide group, a cyclic ether group, a sulfide
group, an acetal group or a lactone group. In addition, a specific
type of the above-described resin may be an acryl resin, a
polyester resin, an isocyanate resin or an epoxy resin, but the
present invention is not limited thereto.
[0033] In the present invention, as the curable resin, an aromatic
or aliphatic, or linear, or branched epoxy resin may be used. In
one exemplary embodiment of the present invention, an epoxy resin
comprising at least two functional groups and having an epoxy
equivalent of 180 to 1,000 g/eq may be used. As the epoxy resin
having the above range of epoxy equivalent is used, properties of
the cured product such as adhesive performance and a glass
transition temperature may be effectively maintained. Such an epoxy
resin may be one or a mixture of at least two of a cresol novolac
epoxy resin, a bisphenol A-type epoxy resin, a bisphenol A-type
novolac epoxy resin, a phenol novolac epoxy resin, a
tetrafunctional epoxy resin, a biphenyl-type epoxy resin, a
triphenol methane-type epoxy resin, an alkyl-modified triphenol
methane epoxy resin, a naphthalene-type epoxy resin, a
dicyclopentadiene-type epoxy resin, and a dicyclopentadiene
modified phenol-type epoxy resin.
[0034] In the present invention, as the curable resin, an epoxy
resin including a cyclic structure in a molecular structure may be
used, or an epoxy resin including an aromatic group (for example, a
phenyl group) may be used. When the epoxy resin includes an
aromatic group, a cured product may have excellent thermal and
chemical stabilities, and exhibit a low moisture absorption amount,
and thus reliability of the encapsulation structure of the OED may
be enhanced. As a specific example of the epoxy resin comprising an
aromatic group which can be used in the present invention, one or a
mixture of at least two of a biphenyl-type epoxy resin, a
dicyclopentadiene-type epoxy resin, a naphthalene-type epoxy resin,
a dicyclopentadiene-modified phenol-type epoxy resin, a
cresol-based epoxy resin, a bisphenol-based epoxy resin, a
xylol-based epoxy resin, a multifunctional epoxy resin, a phenol
novolac epoxy resin, a triphenolmethane-type epoxy resin and an
alkyl-modified triphenolmethane epoxy resin may be used, but the
present invention is not limited thereto.
[0035] In the present invention, as the epoxy resin, a
silane-modified epoxy resin, or a silane-modified epoxy resin
having an aromatic group may be used. Likewise, when an epoxy resin
which has a silane group structurally modified by a silane is used,
an adhesive property to a glass substrate or an inorganic material
of the substrate of the OED may be maximized, and a moisture
barrier property or durability and reliability may be enhanced. A
specific type of the epoxy resin which can be used in the present
invention is not particularly limited, and such a resin may be
easily obtained from a manufacturer such as Kukdo Chemical, Co.,
Ltd.
[0036] In an exemplary embodiment of the present invention, a light
absorbing region of the encapsulation film may include a light
absorbing material, and the type or content of the light absorbing
material may be appropriately controlled by those of ordinary skill
in the art to satisfy the above-described range of the light
transmittance of the film.
[0037] The term "light absorbing material" used herein may be a
material which can absorb visible rays, for example, a pigment or a
dye.
[0038] In one example, the light absorbing material may be a
non-conductive material. When the encapsulation composition
including the light absorbing material is manufactured in a film
shape to be applied in encapsulation of the OED, if the film has
electric conductivity, a defect in driving of the OED is induced.
Accordingly, as a non-conductive material is used as a light
absorbing material, the surface resistance of the film may be
limited in the above-described range, a defect in driving of the
OED according to electric conductivity of the film may be
prevented.
[0039] The light absorbing material is not particularly limited,
but may be, for example, a pigment or a dye. In one example, the
light absorbing material may be any material capable of absorbing
light in an entire range of wavelength or a specific wavelength
range, and may be, but is not particularly limited to, for example,
carbon black, carbon nanotube, fluorene (C6), a phthalocyanine
derivative, a porphyrin derivative, a triphenylamine derivative or
a mixture thereof. In one example, the light absorbing material may
be included at 0.01 parts by weight or more, 0.01 to 50 parts by
weight, 0.6 to 40 parts by weight, 0.7 to 30 parts by weight, 0.8
to 20 parts by weight, 0.9 to 14 parts by weight, 1.0 to 13, or 1.0
to 12 parts by weight with respect to 100 parts by weight of the
encapsulation resin. As the light absorbing material is adjusted
within the above range, when the encapsulation composition is
applied to an OED, internal or external light may be effectively
absorbed and blocked to prevent reflection or scattering of the
light.
[0040] In yet another exemplary embodiment, the light absorbing
material may be adjusted to absorb a light source in a specific
wavelength range as needed.
[0041] The light absorbing layer or moisture barrier layer of the
encapsulation film of the present invention may include a moisture
absorbent as needed. The term "moisture absorbent" may include all
components which can adsorb or remove moisture or vapor permeated
from an external environment through a physical or chemical
reaction. That is, the moisture absorbent may be a moisture
reactive adsorbent, a physical adsorbent, or a mixture thereof.
[0042] The moisture reactive adsorbent adsorbs moisture or vapor by
a chemical reaction with vapor, moisture or oxygen permeated into
the encapsulation film. The permeation to the physical adsorbent
may be inhibited by extending a movement path of moisture or vapor
permeated into the encapsulation structure, and the physical
adsorbent may maximize a blocking property to moisture and vapor
through interaction with a matrix structure of the encapsulation
resin and the moisture reactive adsorbent
[0043] A specific type of the moisture absorbent which can be used
in the present invention is not particularly limited, and for
example, the moisture reactive adsorbent may be one or a mixture of
at least two of metal powders such as alumina, a metal oxide, a
metal salt, and phosphorus pentoxide (P.sub.2O.sub.5), and the
physical adsorbent may be silica, zeolite, titania, zirconia or
montmorillonite.
[0044] Here, specifically, the metal oxide may be lithium oxide
(Li.sub.2O), sodium oxide (Na.sub.2O), barium oxide (BaO), calcium
oxide (CaO) or magnesium oxide (MgO), and the metal salt may be,
but is not limited to, a sulfate such as lithium sulfate
(Li.sub.2SO.sub.4), sodium sulfate (Na.sub.2SO.sub.4), calcium
sulfate (CaSO.sub.4), magnesium sulfate (MgSO.sub.4), cobalt
sulfate (CoSO.sub.4), gallium sulfate (Ga.sub.2(SO.sub.4).sub.3),
titanium sulfate (Ti(SO.sub.4).sub.2) or nickel sulfate
(NiSO.sub.4); a metal halide such as calcium chloride (CaCl.sub.2),
magnesium chloride (MgCl.sub.2), strontium chloride (SrCl.sub.2),
yttrium chloride (YCl.sub.3), copper chloride (CuCl.sub.2), cesium
fluoride (CsF), tantalum fluoride (TaF.sub.5), niobium fluoride
(NbF.sub.5), lithium bromide (LiBr), calcium bromide (CaBr.sub.2),
cesium bromide (CeBr.sub.3), selenium bromide (SeBr.sub.4),
vanadium bromide (VBr.sub.3), magnesium bromide (MgBr.sub.2),
barium iodide (BaI.sub.2) or magnesium iodide (MgI.sub.2); or a
metal chlorate such as barium perchlorate (Ba(ClO.sub.4).sub.2) or
magnesium perchlorate (Mg(ClO.sub.4).sub.2), but the present
invention is not limited thereto.
[0045] In the present invention, the moisture absorbent such as the
metal oxide may be suitably processed, and mixed in the
composition. For example, depending on the type of the OED to which
the encapsulation film is applied, the encapsulating composition
may be formed in the form of a thin film having a thickness of 30
.mu.m or less, and in this case, a grinding process of the moisture
absorbent may be needed. To grind the moisture absorbent,
three-roll milling, bead milling or ball milling may be used.
[0046] The light absorbing layer or moisture barrier layer of the
encapsulation film of the present invention may include the
moisture absorbent at 0 to 100, 1 to 90, 5 to 80, or 10 to 60 parts
by weight with respect to 100 parts by weight of the encapsulation
resin. The moisture absorbent is an optional component, and thus
may not be included. However, as the content of the moisture
absorbent is controlled to 5 parts by weight or more, a cured
product may exhibit an excellent moisture and vapor blocking
property. In addition, as the content of the moisture absorbent is
controlled to 100 parts by weight or less, a thin film-type
encapsulation structure may be formed, and an excellent moisture
barrier property may be exhibited.
[0047] In the specification, unless particularly defined otherwise,
the unit "parts by weight" means a weight ratio between
components.
[0048] In an exemplary embodiment of the present invention, the
moisture absorbent may be suitably controlled according to a
structure for encapsulating an organic electronic element. For
example, in a layer in contact with the organic electronic element,
the moisture absorbent may be included at 0 to 20% based on the
total weight of the moisture absorbent in the encapsulation film.
For example, as shown in FIGS. 3 and 4, when the element is in
contact with one (the moisture barrier layer 6) of the two moisture
barrier layers 4 and 6, which are sequentially stacked, during the
encapsulation of the organic electronic element, the underlying
moisture barrier layer 6 may include 0 to 20% of the moisture
absorbent based on the total weight of the moisture absorbent, and
the upper moisture barrier layer 4 which is not in contact with the
organic electronic element may include 80 to 100% of the moisture
absorbent based on the total weight of the moisture absorbent.
[0049] The light absorbing layer or moisture barrier layer of the
encapsulation film of the present invention may include a filler,
and preferably, an inorganic filler when needed. The filler may
extend a movement path of moisture or vapor permeated into the
encapsulation structure to inhibit the permeation, and maximize a
blocking property to moisture and vapor through interaction with
the matrix structure of the encapsulation resin and the moisture
absorbent. A specific type of the filler which can be used in the
present invention may be, but is not particularly limited to, for
example, one or a mixture of at least two of clay, talc, and
silica.
[0050] In addition, in the present invention, to increase binding
efficiency to the filler and an organic binder, as the filler, a
product whose surface is treated with an organic material may be
used, or a coupling agent may be additionally added.
[0051] The light absorbing layer or moisture barrier layer of the
encapsulation film of the present invention may include the filler
at 0 to 50, 1 to 40, or 1 to 20 parts by weight with respect to 100
parts by weight of the encapsulation resin. In the present
invention, the filler is an optional component, and may not be
included in the encapsulation film. However, a content of the
filler is controlled to 1 part by weight or more, and thus an
encapsulation structure having an excellent moisture or vapor
blocking property and physical properties may be provided. In
addition, in the present invention, as the content of the filler is
controlled to 50 parts by weight or less, the encapsulation film
may be manufactured in a film shape, and even when the
encapsulation film is manufactured in a thin film, a cured product
may exhibit an excellent moisture barrier property.
[0052] The term "encapsulation structure" used herein may be the
above-described encapsulation film having a single layer or
multilayer structure, and may be a product for encapsulating an OED
including an encapsulation film encapsulating an entire surface of
the OED and an organic electronic element.
[0053] In addition, in one example, the encapsulation film may
further include a dispersant such that the light absorbing material
or the moisture absorbent may be uniformly dispersed. As the
dispersant which can be used herein, for example, a non-ionic
surfactant having affinity to a surface of the light absorbing
material, and compatibility with the encapsulation resin may be
used.
[0054] In one exemplary embodiment of the present invention, the
light absorbing layer or the moisture barrier layer of the
encapsulation film may further include a curing agent according to
a type of the encapsulation resin. For example, a curing agent
which can form a crosslinking structure by a reaction with the
above-described encapsulation resin, or an initiator which can
initiate a curing reaction of the resin may be further
included.
[0055] A suitable type of the curing agent may be selected and used
according to a type of the encapsulation resin or a type of a
functional group included in the resin.
[0056] In one example, when the encapsulation resin is an epoxy
resin, as a curing agent of the epoxy resin known in the art, for
example, one or at least two of an amine curing agent, an imidazole
curing agent, a phenol curing agent, a phosphorus curing agent, and
an acid anhydride curing agent may be used, but the present
invention is not limited thereto.
[0057] In one example, as the curing agent, an imidazole compound
which is a solid at room temperature, and having a melting point or
degradation temperature of 80.degree. C. or more may be used. Such
a compound may be, but is not limited to, for example, 2-methyl
imidazole, 2-heptadecyl imidazole, 2-phenyl imidazole,
2-phenyl-4-methyl imidazole, or 1-cyanoethyl-2-phenyl
imidazole.
[0058] A content of the curing agent may be selected according to,
for example, the type or ratio of the encapsulation resin. For
example, the curing agent may be included at 1 to 20, 1 to 10, or 1
to 5 parts by weight with respect to 100 parts by weight of the
encapsulation resin. However, the weight ratio may be changed
according to the type and ratio of the encapsulation resin or a
functional group of the resin, or a crosslinking density to be
realized.
[0059] When the encapsulation resin is a resin that may be cured by
radiation of active energy rays, as an initiator, for example, a
cationic photopolymerization initiator may be used.
[0060] As the cationic photopolymerization initiator, an onium
salt- or organometallic salt-series ionized cationic initiator, or
an organic silane- or latent sulfonic acid-series ionized cationic
photopolymerization initiator, or a non-ionized cationic
photopolymerization initiator may be used. The onium salt-series
initiator may be a diaryliodonium salt, a triarylsulfonium salt, or
an aryldiazonium salt, the organometallic salt-series initiator may
be iron arene, the organic silane-series initiator may be
o-nitrobenzyl triaryl silyl ether, triaryl silyl peroxide, or acyl
silane, and the latent sulfonic acid-series initiator may be
.alpha.-sulfonyloxy ketone or .alpha.-hydroxymethylbenzoin
sulfonate, but the present invention is not limited thereto.
[0061] In one example, as the cationic initiator, an ionized
cationic photopolymerization initiator may be used.
[0062] In addition, when the encapsulation resin is a resin which
can be cured by the radiation of active energy rays, as an
initiator, for example, a radical initiator may be used.
[0063] The radical initiator may be a photoinitiator or a thermal
initiator. A specific type of the photoinitiator may be suitably
selected in consideration of a curing speed and yellowing
probability. For example, the photoinitiator may be a benzoin-,
hydroxy ketone-, amino ketone-, or phosphine oxide-based
photoinitiator, and specifically, benzoin, benzoin methylether,
benzoin ethylether, benzoin isopropylether, benzoin n-butylether,
benzoin isobutylether, acetophenone, dimethylamino acetophenone,
2,2-dimethoxy-2-phenylacetophenone,
2,2-diethoxy-2-phenylacetophenone,
2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxy
cyclohexylphenylketone,
2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane-1-one,
4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone,
p-phenylbenzophenone, 4,4'-diethylamino benzophenone,
dichlorobenzophenone, 2-methyl anthraquinone, 2-ethylanthraquinone,
2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone,
2-ethylthioxanthone, 2-chlorothioxanthone,
2,4-dimethylthioxanthone, 2,4-diethylthioxanthone,
benzyldimethylketal, acetophenone dimethylketal, p-dimethylamino
benzoic acid ester,
oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], or
2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide.
[0064] A content of the initiator, like the curing agent, may be
changed according to the type and ratio of the encapsulation resin
or a functional group of the resin, or a crosslinking density to be
realized. For example, the initiator may be included at 0.01 to 10
parts by weight or 0.1 to 3 parts by weight with respect to 100
parts by weight of the encapsulation resin.
[0065] The light absorbing layer or moisture barrier layer of the
encapsulation film of the present invention may further include a
high molecular weight resin. When the encapsulation composition of
the present invention is molded in a film or sheet shape, the high
molecular weight resin may serve to improve moldability. In
addition, when a hot melting process is performed, the high
molecular weight resin may serve as a high temperature viscosity
controlling agent for controlling flowability.
[0066] A type of the high molecular weight resin which can be used
herein is not particularly limited as long as the resin has
compatibility with another component of the encapsulation resin. A
specific example of the high molecular weight resin which can be
used herein is a resin having a weight average molecular weight of
20,000 or more, for example, one or a mixture of at least two of a
phenoxy resin, an acrylate resin, a high molecular weight epoxy
resin, an ultra high molecular weight epoxy resin, a high polarity
functional group-containing rubber, and a high polarity functional
group-containing reactive rubber, but the present invention is not
limited thereto.
[0067] When the high molecular weight resin is included in the
encapsulation composition of the present invention, the content of
the resin is adjusted according to a desired physical property, and
is not particularly limited. For example, in the present invention,
the high molecular weight resin may be included at approximately
200 parts by weight or less, preferably 150 parts by weight or
less, and more preferably approximately 100 parts by weight or
less, with respect to 100 parts by weight of the encapsulation
resin. As the content of the high molecular weight resin of the
present invention is controlled to 200 parts by weight or less,
compatibility with each component of the resin composition may be
effectively maintained, and thus the resin may serve as an
adhesive.
[0068] In the encapsulation composition constituting the light
absorbing layer or moisture barrier layer according to the present
invention, various additives may be included according to a use, a
type of the encapsulation resin and a process of manufacturing an
encapsulation film which will be described below without affecting
the effect of the present invention, in addition to the
above-described components. For example, the encapsulation
composition may include a coupling agent, a crosslinking agent, a
curable material, a tackifier, a UV stabilizer or an antioxidant in
a suitable range of contents according to desired physical
properties. Here, the curable material may mean a material having a
heat-curable functional group and/or an active energy ray-curable
functional group separately included, other than the
above-described components constituting the encapsulation
composition. For example, the curable material may mean a compound
including at least two of functional groups which can participate
in polymerization by the radiation of active energy rays, for
example, a functional group including an ethylenically unsaturated
double bond such as an acryloyl group or a methacryloyl group, and
a functional group such as an epoxy group or an oxetane group.
[0069] In an exemplary embodiment of the present invention, the
encapsulation film may further include a metal layer, in addition
to the light absorbing layer or the moisture barrier layer. The
metal layer according to an exemplary embodiment of the present
invention may be transparent or opaque. The metal layer may be a
thin film-type metal foil, or a layer formed by depositing a metal
on a polymer base film. The metal layer may be formed of any
material that can have thermal conductivity and a moisture barrier
property without limitation. The metal layer may include any one of
a metal, a metal oxide, a metal nitride, a metal carbide, a metal
oxynitride, a metal oxyboride, and a mixture thereof. For example,
the metal layer may include an alloy prepared by adding at least
one metallic element or non-metallic element to one metal, for
example, an iron-nickel alloy or stainless steel (SUS). In
addition, in one example, the metal layer may include copper,
aluminum, nickel, silicon oxide, aluminum oxide, titanium oxide,
indium oxide, tin oxide, tin-indium oxide, tantalum oxide,
zirconium oxide, niobium oxide, and a mixture thereof. The metal
layer may be deposited by means of electrolysis, rolling,
evaporation, electron beam evaporation, sputtering, reactive
sputtering, chemical vapor deposition, plasma chemical vapor
deposition, or electron cyclotron resonance source plasma chemical
vapor deposition. In one exemplary embodiment of the present
invention, the metal layer may be deposited by reactive sputtering.
In one exemplary embodiment of the present invention, the
encapsulation film including the metal layer may prevent reflection
or scattering of external light in a non-deposited part of an
electrical connection of the OED by the metal layer using the light
absorbing region.
[0070] In one example, the metal layer may have a reflectance of 15
to 90, 18 to 88, or 20 to 86% in a specular component included
(SCI) measurement. In addition, the metal layer may have a
reflectance of 15 to 80, 18 to 75, 20 to 70, or 20 to 65% in a
specular component excluded (SCE) measurement. Here, the SCI
denotes total reflectance, and the SCE denotes an irregular
reflectance caused by scattering. The reflectance may be measured
by a known method in the art using, for example, the CM2006d
produced by Konika Minolta (measurement condition: any one of the
predetermined values from M/I+E, M/SCI, M/SCE, S/I+E, S/SCI and
S/SCE, any one of the predetermined values from UV 0 to 100%, any
one of the light sources from D65, D50, C, A, F2, F6, F7, F8, F10,
F11 and F12, and an observation view of 10.degree. or 2.degree.).
When the encapsulation film includes a metal layer, due to the
difference in reflectance between the electrical metal connection
of the OED and the metal layer, in the observation of the OED from
an external environment, the electrical connection is observed.
Particularly, when the light absorbing layer includes a moisture
absorbent or a filler, or the moisture barrier layer includes a
moisture absorbent or a filler, the light absorbing layer or the
moisture barrier layer serves as an intermediate layer in which
light is scattered. Accordingly, an effect of reducing a
reflectance of a polarizer formed on one surface of the OED is
degraded, and thus a part without the electrical metal connection
is seen blurred. Therefore, as described above, the encapsulation
film including the metal layer may prevent reflection or scattering
of external light from a non-deposited part of an electrical
connection of the OED by the metal layer using a light absorbing
region.
[0071] The metal layer may have a thermal conductivity of 50 W/mK
or more, 60 W/mK or more, 70 W/mK or more, 80 W/mK or more, 90 W/mK
or more, 100 W/mK or more, 110 W/mK or more, 120 W/mK or more, 130
W/mK or more, 140 W/mK or more, 150 W/mK or more, 200 W/mK or more,
or 250 W/mK or more. As the metal layer has the above-described
high thermal conductivity, heat generated at a contact interface in
a process of contacting the metal layer may be more rapidly
emitted. In addition, due to the high thermal conductivity, heat
accumulated in the operation of the OED is rapidly emitted to an
external environment, and thus a temperature of the OED may be
maintained lower, and the generation of a crack and a defect is
reduced.
[0072] The term "thermal conductivity" used herein is a degree of
an ability of a material to deliver heat through conduction, and a
unit may be W/mK. The unit shows the degree in which heat is
delivered from a material at the same temperature and distance, and
is a unit of heat (watt) with respect to the unit of a distance
(meter) and the unit of a temperature (Kelvin).
[0073] A structure of the encapsulation film of the present
invention may be, but is not particularly limited to, for example,
a structure including a base film or a releasing film (hereinafter,
also referred to as a "first film"); and the light absorbing layer
or the moisture barrier layer formed on the base film or the
releasing film.
[0074] The encapsulation film of the present invention may further
include a base film or a releasing film (hereinafter, also referred
to as a "second film") formed on the light absorbing layer or
moisture barrier layer.
[0075] A specific type of the first film which can be used in the
present invention is not particularly limited. In the present
invention, as the first film, for example, a polymer film generally
used in the art may be used. In the present invention, for example,
as the base or releasing film, a polyethyleneterephthalate film, a
polytetrafluoroethylene film, a polyethylene film, a polypropylene
film, a polybutene film, a polybutadiene film, a vinylchloride
copolymer film, a polyurethane film, an ethylene-vinyl acetate
film, an ethylene-propylene copolymer film, an ethylene-ethyl
acrylate copolymer film, an ethylene-methyl acrylate copolymer film
or a polyimide film may be used. In addition, one or both surfaces
of the base film or releasing film of the present invention may be
treated with suitable releasing treatment. As an example of a
releasing agent used in the releasing treatment for the base film,
an alkyd-, silicone-, fluorine-, unsaturated ester-, polyolefin- or
wax-based releasing agent may be used, and in terms of thermal
resistance, an alkyd-, silicone- or fluorine-based releasing agent
is preferably used, but the present invention is not limited
thereto.
[0076] In addition, a type of the second film which can be used in
the present invention (hereinafter, referred to as a "cover film")
is not particularly limited, either. For example, in the present
invention, as the second film, in the above-listed category of the
first film, the same or different type of film, compared to the
first film, may be used. In addition, in the present invention, the
second film may also be treated with a suitable releasing
treatment.
[0077] In the present invention, a thickness of the above-described
base film or releasing film (first film) may be, but is not
particularly limited to, suitably selected according to a use. For
example, the thickness of the first film in the present invention
may be approximately 10 to 500 .mu.m, and preferably 20 to 200
.mu.m. When the thickness is less than 10 .mu.m, the base film may
be easily deformed in a manufacturing process, and when the
thickness is more than 500 .mu.m, economic feasibility is
degraded.
[0078] In the present invention, a thickness of the second film is
not particularly limited, either. In the present invention, for
example, the thickness of the second film may be set the same as
the first film. In the present invention, in consideration of
processability, the thickness of the second film may be set
relatively smaller than that of the first film.
[0079] A thickness of the light absorbing layer or the moisture
barrier layer included in the encapsulation film of the present
invention is not particularly limited, and may be suitably selected
according to the following condition in consideration of a use to
which the film is applied. The thickness of the light absorbing
layer or moisture barrier layer included in the encapsulation film
of the present invention may be approximately 5 to 200 .mu.m, and
preferably 10 to 150 .mu.m.
[0080] In the present invention, a method of manufacturing the
encapsulation film is not particularly limited. For example, the
encapsulation film may be manufactured by a method including a
first operation of coating a base film or a releasing film with a
coating solution including the above-described encapsulation
composition; and a second operation of drying the coating solution
coated in the first operation.
[0081] A method of stacking a light absorbing layer or a moisture
barrier layer is not particularly limited. For example, the light
absorbing layer or the moisture barrier layer formed on a separate
releasing film may be laminated, thereby forming an encapsulation
film having a multilayer structure, and a moisture barrier layer
may be directly formed on the light absorbing layer, or vice
versa.
[0082] In the method of manufacturing an encapsulation film of the
present invention, a third operation of additionally pressing a
base film or a releasing film on the coating solution dried in the
second operation may be further included.
[0083] The first operation of the present invention is to prepare a
coating solution by dissolving or dispersing the above-described
encapsulation composition in a suitable solvent. In this operation,
a content of the encapsulation resin included in the coating
solution may be suitably controlled according to a desired moisture
barrier property and film moldability.
[0084] A type of the solvent used in the preparation of the coating
solution in the present invention is not particularly limited.
However, when a drying time of the solvent is excessively long, or
drying at a high temperature is needed, problems in workability or
durability of the encapsulation film may occur, and thus a solvent
having a volatilization temperature of 100.degree. C. or less is
preferably used. In the present invention, in consideration of film
moldability, a small amount of a solvent having a volatilization
temperature in the above range or more may be mixed. An example of
the solvent which can be used in the present invention, one or a
mixture of at least two of methylethylketone (MEK), acetone,
toluene, dimethylformamide (DMF), methylcellosolve (MCS),
tetrahydrofuran (THF) or N-methylpyrrolidone (NMP) may be used, but
the present invention is not limited thereto.
[0085] In the first operation of the present invention, a method of
coating a base film or a releasing film with the coating solution
may be, but is not particularly limited to, for example, a known
method such as knife coating, roll coating, spray coating, gravure
coating, curtain coating, comma coating or lip coating.
[0086] The second operation of the present invention is to form a
light absorbing layer or a moisture barrier layer by drying the
coating solution coated in the first operation. That is, in the
second operation of the present invention, the light absorbing
layer or the moisture barrier layer may be formed by drying and
removing the solvent by heating the coating solution coated on the
film. Here, a drying condition is not particularly limited, and for
example, the drying may be performed at 70 to 200.degree. C. for 1
to 10 minutes.
[0087] In the method of manufacturing an encapsulation film of the
present invention, after the second operation, a third operation of
pressing an additional base film or releasing film on the light
absorbing layer or moisture barrier layer formed on the film may be
further performed.
[0088] The third operation of the present invention may be
performed by pressing an additional releasing film or base film
(cover film or second film) on the light absorbing layer or
moisture barrier layer formed by coating the film with the coating
solution and drying the coated layer though hot roll lamination or
pressing.
[0089] In addition, as shown in FIG. 9, the present invention
relates to an OED including a substrate 21; an organic electronic
element 23 including a transparent electrode layer present on the
substrate, an organic layer present on the transparent electrode
layer and including at least an emitting layer and a reflective
electrode layer present on the organic layer; and the encapsulation
film 1 encapsulating an entire surface of the organic electronic
element 23, and having a light absorbing region having a surface
resistance of 10.sup.11 .OMEGA./cm.sup.2 or more.
[0090] The organic layer may be formed in various structures
further including various functional layers known in the art as
long as including an emitting layer. A layer which can be included
in the organic layer may be an electron injection layer, a hole
blocking layer, an electron transport layer, a hole transport
layer, and a hole injection layer.
[0091] Various materials and methods of forming the same known in
the art may be used to form a hole or electron injection electrode
layer and an organic layer, for example, an emitting layer, an
electron injection or transport layer, or a hole injection or
transport layer, but the present invention is not limited
thereto.
[0092] The organic electronic element 23 of the present invention
may be an OLED.
[0093] In one example, the OED according to the present invention
may be a bottom-emitting OED.
[0094] The OED may further include a protective film protecting the
organic electronic element between the encapsulation film and the
organic electronic element.
[0095] In addition, the OED may include an encapsulation film
further including a metal layer, and in this case, a cover
substrate which will be described below may be omitted.
[0096] In yet another embodiment of the present invention, a method
of manufacturing an OED includes forming an organic electronic
element including a transparent electrode layer, an organic layer
present on the transparent electrode layer and including at least
an emitting layer and a reflective electrode layer present on the
organic layer on a substrate; and applying the above-described
encapsulation film to the substrate on which the organic electronic
element is formed to encapsulate an entire surface of the organic
electronic element.
[0097] The operation of applying the encapsulation film to the OED
may be performed by hot roll lamination, hot pressing or vacuum
pressing of the encapsulation film, but the present invention is
not particularly limited thereto.
[0098] The operation of applying the encapsulation film to the OED
may be performed at 50 to 90.degree. C., and then curing may be
performed thereon by heating at a temperature range of 70 to
110.degree. C. or radiating UV rays.
[0099] FIG. 9 is a cross-sectional view of an OED according to an
exemplary embodiment of the present invention.
[0100] According to the method of manufacturing an OED in the
present invention, for example, a transparent electrode is formed
on the substrate 21 such as a glass or a film by vacuum deposition
or sputtering, and an organic material layer is formed on the
transparent electrode. The organic material layer may include a
hole injection layer, a hole transport layer, an emitting layer, an
electron injection layer and/or an electron transport layer.
Subsequently, a second electrode is further formed on the organic
material layer. Afterward, the above-described encapsulation film 1
is applied to an upper portion of an OED 23 on the substrate 21 to
entirely cover the OED 23. Here, the method of applying the
encapsulation film 1 is not particularly limited, and may be
heating, pressing or autoclaving a cover substrate 22 (e.g., a
glass or a polymer film) to which the encapsulation film 1 of the
present invention is previously transferred, for example, on the
OED 23 formed on the substrate 21. In this operation, for example,
when the encapsulation film 1 is transferred to the cover substrate
22, the encapsulation film 1 may be transferred to the cover
substrate 22 through a vacuum press or a vacuum laminator while
heated, after a base or releasing film formed on the film may be
delaminated. In this operation, when curing of the encapsulation
film 1 is performed in a predetermined range or more, a cohesive
strength or an adhesive strength of the encapsulation film 1 may be
decreased, and thus a process temperature may be controlled at
approximately 100.degree. C. or less, and a process time may be
controlled within 5 minutes. Similarly, even when the cover
substrate 22 to which the encapsulation film 1 is transferred is
applied to the OED 23 through thermal pressing, a vacuum press or a
vacuum laminator may be used. A temperature condition in this
operation may be set as described above, and a process time may be
set within 10 minutes.
[0101] In addition, in the present invention, an additional curing
process may be performed on the encapsulation film to which the OED
is pressed, and such a curing process (main curing) may be
performed, for example, in a heating chamber or a UV chamber, and
preferably a heating chamber. A condition of the main curing may be
suitably selected in consideration of stability of the OED.
[0102] However, the above-described manufacturing process is merely
an example to encapsulate the OED of the present invention, and the
process sequence or process condition may be changed without
limitation. For example, in the present invention, a sequence of
the transferring and pressing processes may be changed into
transferring the encapsulation film 1 of the present invention to
the OED 23 on the substrate 21, and pressing the cover substrate
22. In addition, a protective layer may be formed on the OED 23,
the encapsulation film may be applied to the protective layer, and
then curing may be performed thereon without the cover substrate
22.
Effect
[0103] When an OED is encapsulated using an encapsulation film
according to exemplary embodiments of the present invention, an
excellent moisture barrier property can be realized, and as
reflection or scattering of light is prevented by absorbing and
blocking internal or external light, external defects of the OED
can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0104] FIGS. 1 to 4 are cross-sectional views of an encapsulation
film according to an exemplary embodiment of the present
invention;
[0105] FIGS. 5 to 8 are plan views of an encapsulation film
according to an exemplary embodiment of the present invention;
and
[0106] FIG. 9 is a cross-sectional view of an OED according to an
exemplary embodiment of the present invention.
DESCRIPTION OF REFERENCE NUMERALS
[0107] 1: encapsulation film
[0108] 2: light absorbing layer
[0109] 3: light absorbing material
[0110] 4, 6: moisture barrier layer
[0111] 5: moisture absorbent
[0112] 10: first region (light absorbing region)
[0113] 11: second region (non-light absorbing region)
[0114] 21: substrate
[0115] 22: cover substrate
[0116] 23: organic electronic element
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0117] Hereinafter, exemplary embodiments of the present invention
will be described in detail with reference to Examples according to
the present invention and Comparative Examples not according to the
present invention. However, the scope of the present invention is
not limited to the embodiments which will be disclosed below.
Example 1
[0118] A carbon black dispersed solution was prepared by adding
carbon black (#2600 Mitsubishi Carbon black) having a primary
particle size of approximately 20 nm or less as a light absorbing
material and methylethylketone (MEK) as a solvent in a solid
concentration of 10 wt %. Meanwhile, a moisture absorbent solution
was prepared by adding 100 g of calcined dolomite as a moisture
absorbent and MEK as a solvent in a solid concentration of 50 wt
%.
[0119] 200 g of a silane-modified epoxy resin (KSR-177, Kukdo
Chemical Co., Ltd.) and 150 g of a phenoxy resin (YP-50, Tohto
Kasei Co., Ltd.) were added to a reactor at room temperature, and
diluted with MEK. A solution for a light absorbing layer was
prepared by adding 4 g of an imidazole (Shikoku Chemicals
Corporation) as a curing agent to the homogenized solution, and
stirring the resulting solution at a high speed for 1 hour. The
solution for a light absorbing layer was prepared by adding the
previously prepared moisture absorbent solution to the solution to
have a content of calcined dolomite of 30 parts by weight with
respect to 100 parts by weight of an encapsulation resin of a light
absorbing layer, adding the carbon black dispersed solution to have
a carbon black content of 10 parts by weight with respect to 100
parts by weight of the encapsulation resin of the light absorbing
layer, and mixing the solutions.
[0120] An encapsulation film was manufactured by forming the light
absorbing layer having a thickness of 20 .mu.m by coating a
releasing surface of a releasing PET film with the solution of the
light absorbing layer and drying the coated solution at 130.degree.
C. for 3 minutes.
Example 2
[0121] A carbon black dispersed solution was prepared by adding
carbon black (#2600 Mitsubishi Carbon black) having a primary
particle size of approximately 20 nm or less as a light absorbing
material and MEK as a solvent in a solid concentration of 10 wt
%.
[0122] 200 g of a silane-modified epoxy resin (KSR-177, Kukdo
Chemical Co., Ltd.) and 150 g of a phenoxy resin (YP-50, Tohto
Kasei Co., Ltd.) were added to a reactor at room temperature, and
diluted with MEK. A solution for a light absorbing layer was
prepared by adding 4 g of an imidazole (Shikoku Chemicals
Corporation) as a curing agent to the homogenized solution, and
stirring the resulting solution at a high speed for 1 hour. The
solution for a light absorbing layer was prepared by adding and
mixing the previously prepared carbon black dispersed solution to
the resulting solution to have a carbon black content of 10 parts
by weight with respect to 100 parts by weight of an encapsulation
resin of a light absorbing layer.
[0123] Meanwhile, a moisture absorbent solution was prepared by
adding 100 g of calcined dolomite as a moisture absorbent and MEK
as a solvent at a solid content of 50 wt %.
[0124] 200 g of a silane-modified epoxy resin (KSR-177, Kukdo
Chemical Co., Ltd.) and 150 g of a phenoxy resin (YP-50, Tohto
Kasei Co., Ltd.) were added to a reactor at room temperature, and
diluted with MEK. A solution for a moisture barrier layer was
prepared by adding 4 g of an imidazole (Shikoku Chemicals
Corporation) as a curing agent to the homogenized solution, and
stirring the resulting solution at a high speed for 1 hour. The
previously prepared moisture absorbent solution was added to the
solution to have a content of calcine dolomite of 30 parts by
weight with respect to 100 parts by weight of the encapsulation
resin of a moisture barrier layer.
[0125] A moisture barrier layer having a thickness of 20 .mu.m was
formed by coating a releasing surface of a releasing PET film with
the solution of the moisture barrier layer, and drying the
resulting surface at 130.degree. C. for 3 minutes. According to the
same method as described above, a light absorbing layer having a
thickness of 10 .mu.m was formed by coating a releasing surface of
a releasing PET film with the solution of the light absorbing
layer, and drying the resulting surface at 130.degree. C. for 3
minutes. The moisture barrier layer and the light absorbing layer
were laminated, thereby manufacturing an encapsulation film having
a bilayer structure including the moisture barrier layer and the
light absorbing layer.
Example 3
[0126] A moisture barrier layer having a thickness of 20 .mu.m was
formed by coating a releasing surface of a releasing PET film with
the solution of the moisture barrier layer prepared in Example 2,
and drying the resulting surface at 130.degree. C. for 3 minutes.
According to the same method as described above, a light absorbing
layer having a thickness of 5 .mu.m was formed by coating a
releasing surface of a releasing PET film with the solution of the
light absorbing layer prepared in Example 2, and drying the
resulting surface at 130.degree. C. for 3 minutes.
[0127] The moisture barrier layer and the light absorbing layer
were laminated to have a triple layer structure including the light
absorbing layer/moisture barrier layer/light absorbing layer,
thereby manufacturing an encapsulation film.
Example 4
[0128] An encapsulation film was manufactured by the same method as
described in Example 1, except that a carbon black dispersed
solution was added to have a carbon black content of 1 part by
weight with respect to 100 parts by weight of an encapsulation
resin of a light absorbing layer.
Example 5
[0129] An encapsulation film was manufactured by the same method as
described in Example 2, except that a moisture absorbent was added
to have a content of 10 parts by weight with respect to 100 parts
by weight of an encapsulation resin.
Comparative Example 1
[0130] An encapsulation film was manufactured by the same method as
described in Example 1, except that carbon black (#3030B,
Mitsubishi Carbon black, approximately 55 nm) having conductivity
was added as a carbon black at 15 parts by weight with respect to
100 parts by weight of an encapsulation resin.
Comparative Example 2
[0131] An encapsulation film was manufactured by the same method as
described in Example 2, except that carbon black (#3030B,
Mitsubishi Carbon black, approximately 55 nm) having conductivity
was added as a carbon black at 10 parts by weight with respect to
100 parts by weight of an encapsulation resin.
Comparative Example 3
[0132] An encapsulation film was manufactured by the same method as
described in Comparative Example 2, except that a moisture
absorbent was added at 5 parts by weight with respect to 100 parts
by weight of an encapsulation resin.
[0133] 1. Measurement of Light Transmittance and Haze
[0134] A light transmittance of a light absorbing region of the
film manufactured above was measured at 550 nm using an UV-Vis
spectrometer. When the film was manufactured in a single layer
structure, the light transmittance was measured on the light
absorbing region of a light absorbing layer in a thickness
direction, and when the film was manufactured in a multilayer
structure, the light transmittance was measured on the light
absorbing region in a thickness direction in a state in which a
plurality of layers were stacked.
[0135] In addition, a haze was measured according to a JIS K7105
standard test method using a haze meter. The haze was measured on
an entire area of the light absorbing layer when the film was
manufactured in a single layer structure, and measured on an entire
area in a state in which a plurality of layers were stacked when
the film was manufactured in a multilayer structure.
[0136] 2. Measurement of Surface Resistance
[0137] A surface resistance was measured on the light absorbing
region of the film manufactured in the Examples or Comparative
Examples according to a standard test method using an MCP-HT450
surface resistance meter manufactured by Mitsubishi Chemical
Corporation. The surface resistance was measured on the light
absorbing region of the encapsulation film from which a releasing
film was removed, and measured after 500 V of voltage was applied
for 1 minute at 23.degree. C. and 50% R.H. The surface resistance
was measured on the light absorbing region of the light absorbing
layer when the film was manufactured in a single layer structure,
and measured on the light absorbing region in a state in which a
plurality of layers were stacked when the film was manufactured in
a multilayer structure.
[0138] 3. Defect in Driving of Panel
[0139] An OED panel was manufactured by thermal-laminating the
encapsulation film manufactured in the Examples or Comparative
Examples between a TFT on which an organic electronic element was
deposited and a glass. Here, the encapsulation film was attached
such that the light absorbing layer was in contact with a TFT
surface. When power was supplied to the panel manufactured as
described above, and a short occurred or a bright dot was
generated, it was represented as O, and when a short did not occur
or a bright dot was not generated, it was represented as X.
TABLE-US-00001 TABLE 1 Light Surface Defect in transmittance
resistance driving (%) Haze(%) (.OMEGA./cm.sup.2) of panel Example
1 0.5 88 10.sup.13 X Example 2 3 76 10.sup.14 X Example 3 3.5 74
10.sup.12 X Example 4 15 80 10.sup.13 X Example 5 2.8 44 10.sup.13
X Comparative 0 Impossible to 10.sup.10 .largecircle. Example 1
measure Comparative 4 74 10.sup.8.sup. .largecircle. Example 2
Comparative 3.8 34 10.sup.8.sup. .largecircle. Example 3
* * * * *