U.S. patent application number 15/308537 was filed with the patent office on 2017-02-23 for pressure-sensitive adhesive composition.
The applicant listed for this patent is LG CHEM, LTD.. Invention is credited to Hyun Suk KIM, Jung Ok MOON, Se Woo YANG, Hyun Jee YOO.
Application Number | 20170051184 15/308537 |
Document ID | / |
Family ID | 56564373 |
Filed Date | 2017-02-23 |
United States Patent
Application |
20170051184 |
Kind Code |
A1 |
YOO; Hyun Jee ; et
al. |
February 23, 2017 |
PRESSURE-SENSITIVE ADHESIVE COMPOSITION
Abstract
Provided are a pressure-sensitive adhesive composition, an
encapsulation film including the same, an organic electronic device
including the same, and a method of manufacturing the organic
electronic device. Therefore, provided is the pressure-sensitive
adhesive composition, which can form a structure capable of
effectively blocking moisture or water entering the organic
electronic device from the outside, and have excellent
processability in a process of manufacturing a panel and excellent
heat retention under a high-temperature and high-humidity
condition.
Inventors: |
YOO; Hyun Jee; (Daejeon,
KR) ; KIM; Hyun Suk; (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: |
56564373 |
Appl. No.: |
15/308537 |
Filed: |
February 4, 2016 |
PCT Filed: |
February 4, 2016 |
PCT NO: |
PCT/KR2016/001269 |
371 Date: |
November 2, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09J 7/38 20180101; B32B
7/12 20130101; C08K 3/16 20130101; C09J 133/08 20130101; C09J
2203/326 20130101; C09J 2301/1242 20200801; C09J 7/10 20180101;
H01L 51/5237 20130101; H01L 51/5253 20130101; C08F 255/10 20130101;
C09J 151/04 20130101; B32B 15/20 20130101; C09J 7/381 20180101;
C09J 2301/302 20200801; C09J 4/06 20130101; C09J 7/28 20180101;
C09J 2301/312 20200801; C08K 5/01 20130101; H01L 51/5259 20130101;
B32B 27/36 20130101; C09J 2301/208 20200801; H01L 51/004 20130101;
B32B 2307/724 20130101; C09J 2400/10 20130101; H01L 51/448
20130101; B32B 37/12 20130101; B32B 2307/302 20130101; H01L 23/3135
20130101; C09J 123/22 20130101; H01L 51/56 20130101; B32B 2457/206
20130101; C08K 3/22 20130101; C09J 2423/00 20130101; H01L 23/28
20130101; Y02E 10/549 20130101; C08K 2003/3045 20130101; C09J
2301/40 20200801; H01L 51/107 20130101; B32B 37/1207 20130101; C09J
133/04 20130101; C08K 5/101 20130101; B32B 15/085 20130101; B32B
15/08 20130101; C09J 4/06 20130101; C08F 255/10 20130101; C08F
255/10 20130101; C08F 220/1812 20200201; C08F 255/10 20130101; C08F
220/1812 20200201 |
International
Class: |
C09J 7/02 20060101
C09J007/02; C09J 123/22 20060101 C09J123/22; H01L 51/00 20060101
H01L051/00; H01L 51/56 20060101 H01L051/56; H01L 51/52 20060101
H01L051/52; B32B 7/12 20060101 B32B007/12; C09J 133/08 20060101
C09J133/08 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 4, 2015 |
KR |
10-2015-0017620 |
Claims
1. A pressure-sensitive adhesive composition, comprising: a polymer
derived from butylene; and a compound satisfying Formula 1,
##STR00004## where T is a linear or branched alkyl group, alkenyl
group or alkynyl group having 6 to 30 carbon atoms, or
--U--[O--W]--O-Q, in which U and W are each independently an
alkylene group or alkylidene group, Q is an alkyl group, alkenyl
group, alkynyl group or aryl group, and n is a number from 0 to
10.
2. The composition of claim 1, wherein the polymer derived from
butylene is a homopolymer of a butylene monomer; a copolymer
copolymerizing a butylene monomer with a different monomer capable
of being polymerized therewith; a reactive oligomer using a
butylene monomer; or a mixture thereof.
3. The composition of claim 2, wherein the monomer capable of being
polymerized with the butylene monomer is isoprene, styrene or
butadiene.
4. The composition of claim 2, wherein the reactive oligomer using
the butylene monomer comprises a butylene polymer having a reactive
functional group, and the butylene polymer binds to a different
polymer having a reactive functional group.
5. The composition of claim 1, wherein the polymer derived from
butylene is comprised at 60 to 95 parts by weight, and the compound
satisfying Formula 1 is comprised at 5 to 40 parts by weight.
6. The composition of claim 1, further comprising: a
multifunctional active energy ray polymerizable compound satisfying
Formula 2, ##STR00005## where R.sub.1 is hydrogen or an alkyl group
having 1 to 4 carbon atoms, n is an integer of 2 or higher, and X
is a residue derived from a linear, branched or cyclic alkyl group
having 3 to 30 carbon atoms.
7. The composition of claim 6, wherein the polymer derived from
butylene is comprised at 50 to 90 parts by weight, the compound
satisfying Formula 1 is comprised at 5 to 35 parts by weight, and
the multifunctional active energy ray polymerizable compound of
Formula 2 is comprised at 5 to 25 parts by weight.
8. The composition of claim 1, further comprising: a tackifier.
9. The composition of claim 8, wherein the tackifier is a
hydrogenated cyclic olefin-based polymer.
10. The composition of claim 8, wherein the tackifier is comprised
at 5 to 100 parts by weight with respect to 100 parts by weight of
the polymer.
11. The composition of claim 1, further comprising: a radical
initiator.
12. The composition of claim 11, wherein the radical initiator is a
photoinitiator or thermal initiator.
13. The composition of claim 1, further comprising: a moisture
scavenger.
14. An encapsulation film, comprising: a pressure-sensitive
adhesive layer which comprises the pressure-sensitive adhesive
composition of claim 1 or a crosslinked product thereof.
15. The film of claim 14, wherein the pressure-sensitive adhesive
layer comprises a second layer comprising the pressure-sensitive
adhesive composition of claim 1 or a crosslinked product thereof
and a first layer comprising a pressure-sensitive adhesive resin or
an adhesive resin.
16. The film of claim 14, further comprising: a metal layer formed
on one surface of the pressure-sensitive adhesive layer.
17. The film of claim 16, wherein the metal layer has a thermal
conductivity of 50 W/mK or more.
18. The film of claim 14, wherein the pressure-sensitive adhesive
layer has a water vapor transmission rate (WVTR) in a thickness
direction of 50 g/m.sup.2day or less, while formed to a thickness
of 100 .mu.m.
19. An organic electronic device, comprising: a substrate; an
organic electronic element formed on the substrate; and the
encapsulation film of claim 14, which encapsulates the entire
surfaces of the organic electronic element.
20. A method of manufacturing an organic electronic device,
comprising: applying the encapsulation film of claim 14 to a
substrate on which an organic electronic element is formed to cover
the entire surfaces of the organic electronic element; and curing
the encapsulation film.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 2015-0017620, filed on Feb. 4, 2015 with the Korean
Intellectual Property Office, the disclosure of which is herein
incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present application relates to a pressure-sensitive
adhesive composition, an encapsulation film including the same, an
organic electronic device (OED) including the same, and a method of
manufacturing an OED using the same.
[0004] 2. Discussion of Related Art
[0005] An OED is a device including an organic material layer in
which electric charges are exchanged using holes and electrons, and
the OED may be, for example, a photovoltaic device, a rectifier, a
transmitter, or an organic light emitting diode (OLED).
[0006] Among the OEDs, an OLED has a lower power consumption and a
higher response speed, and is advantageous to a thinner display
device or lighting than a conventional light source. Such an OLED
also has excellent space applicability, and is expected to be
applied to various fields including all kinds of portable devices,
monitors, notebook computers and TVs.
[0007] For commercialization and expanded use of the OLED, the most
critical problem is durability. Organic materials and metal
electrodes included in the OLED are very easily oxidized by an
external factor, for example, moisture. Therefore, a product
including an OLED is very sensitive to environmental factors. For
this reason, various methods have been suggested to effectively
prevent the permeation of oxygen or moisture into an OED such as an
OLED from the outside.
[0008] In Patent Document 1, an adhesive capsulation composition
film and an organic electroluminescent element are disclosed, and
the composition is a polyisobutylene (PIB)-based pressure-sensitive
adhesive, but has low processability and low reliability under a
high-temperature and high-humidity condition. In addition, in a
process of laminating large-scale flat panels, air bubbles are
enclosed between the panels, and therefore a uniform laminating
property may not be obtained.
[0009] Therefore, there is a demand for developing an encapsulant,
which allows an OED to ensure a demanded lifespan, effectively
prevents the permeation of moisture into the OED, maintains
reliability under a high-temperature and high-humidity condition,
and has an excellent laminating property, which is one of the
characteristics required during a process of manufacturing a
panel.
PRIOR ART
Patent Document
[0010] (Patent Document 1) Korean Unexamined Patent Application
Publication No. 2008-0088606
SUMMARY OF THE INVENTION
[0011] The present application provides a pressure-sensitive
adhesive composition which can form a structure capable of
effectively blocking moisture or oxygen entering an OED from the
outside, has excellent processability during a process of
manufacturing a panel and excellent heat retention under a
high-temperature and high-humidity condition, and an encapsulation
film.
[0012] Hereinafter, with reference to the accompanying drawings,
exemplary embodiments of the present application will be described
in further detail. In addition, to explain the present application,
detailed descriptions for known general functions or configurations
will be omitted. In addition, the accompanying drawings are
schematically provided to help in understanding the present
application. To more clearly explain the present application, parts
not relating to the explanation will be omitted, thicknesses are
exaggerated to clearly express several layers and regions. The
scope of the present application is not limited by thicknesses,
sizes, and ratios shown in the drawings.
[0013] The present application relates to a pressure-sensitive
adhesive composition. The pressure-sensitive adhesive composition
may be applied to encapsulate or capsulate an OED such as an
OLED.
[0014] The term "organic electronic device (OED)" used herein is a
product or device having a structure including an organic material
layer in which electric charges are exchanged using holes and
electrons between a pair of electrodes facing each other, and
examples of the OED may include, but the present application is not
limited to, a photovoltaic device, a rectifier, a transmitter, and
an OLED. In an exemplary embodiment of the present application, the
OED may be an OLED.
[0015] The pressure-sensitive adhesive composition of the present
application may be formed in an encapsulation film, for example,
which seals the entire surfaces of an organic electronic element of
the OED so as to protect the element from moisture or oxygen. Such
a pressure-sensitive adhesive composition may include a polymer
derived from butylene and a compound satisfying Formula 1 shown
below. The compound of Formula 1 may include a monofunctional
acrylate.
##STR00001##
[0016] In Formula 1, T may be a linear or branched alkyl group,
alkenyl group or alkynyl group. The alkyl, alkenyl group or alkynyl
group may have a linear or branched structure having 6 to 30, 7 to
25, 8 to 23, 9 to 20, 10 to 19, 6 to 17 or 6 to 11 carbon atoms.
Also, T may be --U--[O--W].sub.n--O-Q. Here, U and W are each
independently an alkylene group or alkylidene group, and Q is an
alkyl group, alkenyl group, alkynyl group or aryl group. Also, n is
a number from 0 to 10, and when n is 0, U may be directly linked to
--O-Q. Since the pressure-sensitive adhesive composition of the
present application includes both of a hydrophobic polymer and the
specific compound of Formula 1, when applied to encapsulation of
the organic electronic element, the composition can exhibit
excellent processability during the process of manufacturing a
panel and excellent heat retention under a high-temperature and
high-humidity condition.
[0017] In an exemplary embodiment, the composition may include 60
to 95 parts by weight of the polymer derived from butylene and 5 to
40 parts by weight of the compound satisfying Formula 1. In an
exemplary embodiment, the composition may include 60 to 90 parts by
weight of the polymer derived from butylene and 10 to 40 parts by
weight of the compound satisfying Formula 1, or 65 to 90 parts by
weight of the polymer derived from butylene and 10 to 35 parts by
weight of the compound satisfying Formula 1. In the present
application, as the contents of the components are adjusted in the
above-described ranges, an excellent moisture blocking property and
heat retention under a high-temperature and high-humidity condition
may be realized. The compound of Formula 1 may include, but is not
particularly limited to, n-octyl acrylate, iso-octyl acrylate,
iso-nonyl acrylate, lauryl acrylate, stearyl acrylate, isostearyl
acrylate, isodecyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate,
methoxytriethyleneglycol acrylate, or methoxypolyethyleneglycol
acrylate.
[0018] The term "alkyl group" used herein may be, unless
particularly defined otherwise, an alkyl group having 1 to 30, 1 to
25, 1 to 20, 1 to 16, 1 to 12, 1 to 8, or 1 to 4 carbon atoms. The
alkyl group may have a linear, branched or cyclic structure, and
may be arbitrarily substituted with at least one substituent.
[0019] Also, the term "alkenyl group" or "alkynyl group" used
herein may be, unless particularly defined otherwise, an alkenyl or
alkynyl group having 2 to 20, 2 to 16, 2 to 12, 2 to 8, or 2 to 4
carbon atoms. The alkenyl or alkynyl group may be linear, branched
or cyclic. Also, the alkenyl group may be arbitrarily substituted
with at least one substituent.
[0020] Also, the term "alkylene group" or "alkylidene group" used
herein may be, unless particularly defined otherwise, an alkylene
or alkylidene group having 2 to 30, 2 to 25, 2 to 20, 2 to 16, 2 to
12, 2 to 10, or 2 to 8 carbon groups. The alkylene group or an
alkylidene group may be linear, branched or cyclic. Also, the
alkylene or alkylidene group may be arbitrarily substituted with at
least one substituent.
[0021] The term "aryl group" used herein may be, unless
particularly defined otherwise, a monovalent residue derived from a
compound including a structure in which benzene is included or two
or more benzenes are condensed or coupled, or a derivative thereof.
The aryl group may have 6 to 22, preferably 6 to 16, and more
preferably 6 to 13 carbon atoms, and may be, for example, a phenyl
group, a phenylethyl group, a phenylpropyl group, a benzyl group, a
tolyl group, a xylyl group or a naphthyl group.
[0022] The term "polymer derived from butylene" may mean that one
or more polymerization units of the polymer are derived from
butylene. Since the polymer derived from butylene has a very low
polarity, is transparent and almost has no influence of corrosion,
when used as an encapsulant or sealant, the polymer may exhibit an
excellent moisture blocking property and durability and
reliability.
[0023] In the present application, also, the polymer derived from
butylene may be a homopolymer of a butylene monomer; a copolymer
formed by copolymerizing a butylene monomer with a different
polymerizable monomer; a reactive oligomer using a butylene
monomer; or a mixture thereof. The polymer derived in the present
application refers that a polymer is formed with a unit of
polymerized monomers. The butylene monomer may include, for
example, 1-butene, 2-butene or isobutylene.
[0024] The butylene monomer or the different monomer capable of
being polymerized with a derivative may include, for example,
isoprene, styrene or butadiene. When the copolymer is used,
physical properties such as processability and a crosslinking
degree may be maintained, and therefore, when applied to the OED,
thermal resistance of the pressure-sensitive adhesive itself may be
ensured.
[0025] Also, the reactive oligomer using a butylene monomer may
include a butylene polymer having a reactive functional group. The
oligomer may have a weight average molecular weight of 500 to 5000.
Also, the butylene polymer may be linked to a different polymer
having a reactive functional group. The different polymer may be an
alkyl (meth)acrylate, but the present application is not limited
thereto. The reactive functional group may be a hydroxyl group, a
carboxyl group, an isocyanate group or a nitrogen-containing group.
Also, the reactive oligomer and the different polymer may be
crosslinked by a multifunctional crosslinking agent, which may be
one or more selected from the group consisting of an isocyanate
crosslinking agent, an epoxy crosslinking agent, an aziridine
crosslinking agent and a metal chelate crosslinking agent.
[0026] In an exemplary embodiment, the polymer derived from
butylene of the present application may be a copolymer of diene and
an olefin-based compound including one carbon-carbon double bond.
Here, the olefin-based compound may include butylene, and the diene
may be a monomer capable of being polymerized with the olefin-based
compound, for example, isoprene or butadiene. For example, the
copolymer of the olefin-based compound including a carbon-carbon
double bond and diene may be butyl rubber.
[0027] In the present application, the polymer may have a certain
weight average molecular weight (MW) so that a pressure-sensitive
adhesive composition can be molded in a film shape. For example,
the polymer may have a weight average molecular weight of about
10,000 to 2,000,000, 10,000 to 1,000,000, 10,000 to 500,000 or
10,000 to 300,000. In the present application, the term "weight
average molecular weight" is a value converted with respect to
standard polystyrene measured by gel permeation chromatography
(GPC). However, the above-described weight average molecular weight
does not necessarily have a resin component. For example, even when
the molecular weight of the resin component is not enough to form a
film, a separate binder resin may be blended in the
pressure-sensitive adhesive composition. The term polymer and the
resin component may have the same meaning as each other.
[0028] In an exemplary example of the present application, the
pressure-sensitive adhesive composition may further include a
multifunctional active energy ray polymerizable compound, which can
be polymerized by irradiation with an active energy ray. The active
energy ray polymerizable compound may satisfy Formula 2.
##STR00002##
[0029] In Formula 2, R.sub.1 is hydrogen or an alkyl group having 1
to 4 carbon atoms, n is an integer of 2 or higher, and X is a
residue derived from a linear, branched or cyclic alkyl group
having 3 to 30 carbon atoms.
[0030] The active energy ray polymerizable compound satisfying
Formula 2 particularly has an excellent compatibility with the
polymer of the present application, and therefore can satisfy
reliability under a high-temperature and high-humidity condition.
For example, the active energy ray polymerizable compound may
realize a pressure-sensitive adhesive composition having an
excellent moisture blocking property and excellent reliability
under a high-temperature and high-humidity condition, along with
the above-described polymer derived from butylene.
[0031] The active energy ray polymerizable compound may refer to a
compound including two or more functional groups capable of
participating in a polymerization reaction by irradiation with an
active energy ray, for example, functional groups including an
ethylene-like unsaturated double bond such as an acryloyl or
methacryloyl group, and functional groups such as an epoxy or
oxetane group.
[0032] As described above, the active energy ray polymerizable
compound may satisfy Formula 2 as follows.
##STR00003##
[0033] In Formula 2, R.sub.1 is hydrogen or an alkyl group having 1
to 4 carbon atoms, n is an integer of 2 or higher, and X is a
residue derived from a linear, branched or cyclic alkyl group
having 3 to 30 carbon atoms. Here, when X is a residue derived from
a cyclic alkyl group, X may be a residue derived from a cyclic
alkyl group having 3 to 30, 6 to 28, 8 to 22, or 12 to 20 carbon
atoms. Also, when X is a residue derived from a linear alkyl group,
X may be a residue derived from a linear alkyl group having 3 to
30, 6 to 25, or 8 to 20 carbon atoms. Also, when X is a residue
derived from a branched alkyl group, X may be a residue derived
from a branched alkyl group having 3 to 30, 5 to 25, or 6 to 20
carbon atoms.
[0034] The term "residue derived from an alkyl group" used herein
may refer to a residue of a specific compound, for example, an
alkyl group. In one example, in Formula 2, when n is 2, X may be an
alkylene group. Also, when n is 3 or higher, two or more hydrogens
are released from an alkyl group of X, and may be bound to a
(meth)acryloyl group of Formula 2.
[0035] The multifunctional active energy ray polymerizable compound
capable of being polymerized by the radiation of an active energy
ray may be used without limitation as long as satisfying Formula 2.
For example, the compound may be 1,4-butanediol di(meth)acrylate,
1,3-butylene glycol di(meth)acrylate, 1,6-hexanediol
di(meth)acrylate, 1,8-octanediol di(meth)acrylate,
1,12-dodecanediol di(meth)acrylate, neopentyl glycol
di(meth)acrylate, dicyclopentanyl di(meth)acrylate,
cyclohexane-1,4-dimethanol di(meth)acrylate, tricyclodecane
dimethanol (meth)diacrylate, dimethylol dicyclopentane
di(meth)acrylate, neopentyl glycol-modified trimethylpropane
di(meth)acrylate, adamantane di(meth)acrylate, trimethylolpropane
tri(meth)acrylate, or a mixture thereof.
[0036] As the multifunctional active energy ray polymerizable
compound, for example, a compound having a molecular weight of less
than 1,000 and including two or more functional groups may be used.
In this case, the molecular weight may refer to a weight average
molecular weight or a conventional molecular weight. A ring
structure included in the multifunctional active energy ray
polymerizable compound may be any one of a carbocyclic structure, a
heterocyclic structure, a monocyclic structure or a multicyclic
structure.
[0037] In an exemplary embodiment, the composition may include 50
to 90 parts by weight of the polymer derived from butylene, 5 to 35
parts by weight of the compound satisfying Formula 1, and 5 to 25
parts by weight of the multifunctional active energy ray
polymerizable compound of Formula 2. In an exemplary embodiment,
the pressure-sensitive adhesive composition may include the polymer
derived from butylene, the compound satisfying Formula 1 and the
multifunctional active energy ray polymerizable compound of Formula
2 in a weight ratio of 50 to 85 parts by weight, 5 to 30 parts by
weight and 10 to 25 parts by weight; or 60 to 85 parts by weight,
10 to 30 parts by weight and 2 to 20 parts by weight, respectively.
In the present application, as the contents of the components are
adjusted in the above ranges, an excellent moisture blocking
property and heat retention under a high-temperature and
high-humidity condition may be realized.
[0038] In an exemplary embodiment, the pressure-sensitive adhesive
composition may further include a tackifier, which is preferably a
hydrogenated cyclic olefin-based polymer. As the tackifier, for
example, a hydrogenated petroleum resin obtained by hydrogenating a
petroleum resin may be used. The hydrogenated petroleum resin may
be partially or completely hydrogenated, or a mixture of such
resins may be used. For the tackifier, one having a high
compatibility with a pressure-sensitive adhesive composition, an
excellent moisture blocking property, and a low content of an
organic volatile component may be selected. As a specific example
of the hydrogenated petroleum resin, a hydrogenated terpene-based
resin, a hydrogenated ester-based resin or a hydrogenated
dicyclopentadiene-based resin may be used. A weight average
molecular weight of the tackifier may be about 200 to 5,000. The
content of the tackifier may be suitably adjusted as necessary. For
example, a content of the tackifier may be selected by considering
the compatibility with a polymer, and according to an example,
based on 100 parts by weight of the polymer, the tackifier may be
included at 5 to 100 parts by weight, 8 to 95 parts by weight, 10
to 93 parts by weight or 15 to 90 parts by weight.
[0039] In an exemplary embodiment of the present application, the
pressure-sensitive adhesive composition may further include a
radical initiator capable of inducing the polymerization reaction
of the above-described active energy ray polymerizable compound.
The radical initiator may be a photoinitiator or thermal initiator.
A specific type of the photoinitiator may be suitably selected by
considering a curing rate and yellowing probability. For example, a
benzoin-based, hydroxy ketone-based, amino ketone-based or
phosphine oxide-based photoinitiator may be used, 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-hydroxycyclohexyl
phenylketone,
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'-diethylaminobenzophenone,
dichlorobenzophenone, 2-methylanthraquinone, 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 may be used.
[0040] The radical initiator may be included at 0.2 to 20 parts by
weight, 0.5 to 18 parts by weight, 1 to 15 parts by weight, or 2 to
13 parts by weight with respect to 100 parts by weight of the
active energy ray polymerizable compound. Therefore, a reaction of
the active energy ray polymerizable compound may be effectively
induced, and degradation of the physical properties of the
pressure-sensitive adhesive composition due to a component
remaining after curing may be prevented.
[0041] The pressure-sensitive adhesive composition may further
include a moisture scavenger when needed. The term "moisture
scavenger" may refer to a material capable of removing moisture or
vapor permeated into an encapsulation film that will be described
later by a chemical reaction therewith. Specifically, the
pressure-sensitive adhesive composition may be applied to
encapsulate an OED, when formed in a film.
[0042] For example, the moisture scavenger may be present to be
uniformly dispersed in the pressure-sensitive adhesive composition
or a pressure-sensitive adhesive layer that will be described
later. Here, the uniformly dispersed state may mean a state in
which the moisture scavenger is present even in any part of the
pressure-sensitive adhesive composition or the pressure-sensitive
adhesive layer at the same or substantially the same density. As
the moisture scavenger, for example, a metal oxide, a sulfate or an
organic metal oxide may be used. Specifically, as an example of the
sulfate, magnesium sulfate, sodium sulfate or nickel sulfate may be
used, and as an example of the organic metal oxide, aluminum oxide
octylate may be used. Here, a specific example of the metal oxide
may be phosphorous pentoxide (P.sub.2O.sub.5), lithium oxide
(Li.sub.2O), sodium oxide (Na.sub.2O), barium oxide (BaO), calcium
oxide (CaO) or magnesium oxide (MgO), and an example of the metal
salt may be 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), or 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 perchloride (Ba(ClO.sub.4).sub.2) or magnesium
perchloride (Mg(ClO.sub.4).sub.2), but the present application is
not limited thereto. As the moisture scavenger that can be included
in the pressure-sensitive adhesive composition, one or two or more
of the above-described components may be used. In an exemplary
embodiment, when the two or more of the above-described components
are used as the moisture scavenger, calcined dolomite may be
used.
[0043] Such a moisture scavenger may be controlled in a suitable
size according to use. In an exemplary embodiment, an average
particle size of the moisture scavenger may be controlled to about
10 to 15000 nm. The moisture scavenger having a size in the above
range may be easily stored since a reaction speed of the moisture
scavenger with moisture is not so fast, and effectively remove
moisture without damage to an element to be encapsulated.
[0044] A content of the moisture scavenger may be suitably selected
by considering a desired blocking property without particular
limitation.
[0045] The pressure-sensitive adhesive composition may also include
a moisture blocker when needed. The term "moisture blocker" used
herein may be a material that has no reactivity with moisture or
can prevent or interfere with the movement of moisture or vapor in
a film. As the moisture blocker, one or two or more of clay, talc,
needle-like silica, plate-like silica, porous silica, zeolite,
titania and zirconia may be used. Also, a surface of the moisture
blocker may be treated with an organic modifier to facilitate
penetration of an organic material. Such an organic modifier may
be, for example, dimethyl benzyl hydrogenated tallow quaternary
ammonium, dimethyl hydrogenated tallow quaternary ammonium, methyl
tallow bis-2-hydroxyethyl quaternary ammonium, dimethyl
hydrogenated tallow 2-ethylhexyl quaternary ammonium, dimethyl
dehydrogenated tallow quaternary ammonium or a mixture thereof.
[0046] A content of the moisture blocker may be suitably selected
by considering a desired blocking property without particular
limitation.
[0047] In addition to the above-described components, various
additives may be included in the pressure-sensitive adhesive
composition according to its use and process of manufacturing a
pressure-sensitive adhesive film that will be described later. For
example, the pressure-sensitive adhesive composition may include a
curable material, a crosslinking agent, or a filler in a suitable
range of content according to a desired physical property.
[0048] The present application also relates to an encapsulation
film. The encapsulation film may include the above-described
pressure-sensitive adhesive composition or a pressure-sensitive
adhesive layer including a crosslinked product thereof.
[0049] In an exemplary embodiment, the pressure-sensitive adhesive
layer may have a single layer structure or multilayer structure
having two or more layers. When the pressure-sensitive adhesive
layer is formed with two or more layers, the composition of each
layer of the pressure-sensitive adhesive layer may be the same as
or different from each other. For example, the encapsulation film
may include a second layer including the above-described
pressure-sensitive adhesive layer and a first layer including a
pressure-sensitive adhesive resin or adhesive resin. The
pressure-sensitive adhesive resin included in the first layer may
be the same as or different from the above-described polymer, and
may be suitably selected by a purpose of those of ordinary skill in
the art. Also, each of the first and second layers may or may not
include the moisture scavenger.
[0050] In an exemplary embodiment, the adhesive resin included in
the first layer may be cured to have an adhesive property, and may
include a curable resin having one or more thermally-curable
functional groups such as a glycidyl group, an isocyanate group, a
hydroxyl group, a carboxyl group or an amide group, or one or more
functional groups capable of being cured by irradiation with
electromagnetic waves, for example, an epoxide group, a cyclic
ether group, a sulfide group, an acetal group or a lactone group.
Also, a specific type of the resin may be, but is not limited to,
an acryl resin, a polyester resin, an isocyanate resin or an epoxy
resin.
[0051] In the present application, as the curable resin, an
aromatic or aliphatic epoxy resin; or a linear or branched epoxy
resin may be used. In an exemplary embodiment of the present
application, the curable resin containing two or more functional
groups may be an epoxy resin having an epoxy equivalent of 180 to
1,000 g/eq. By using the epoxy resin having the above range of
equivalent, properties such as an adhesion performance and a glass
transition temperature of a cured product may be effectively
maintained. As an example of the epoxy resin, one 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, or a mixture of at least two thereof may
be used.
[0052] In an exemplary embodiment of the present application, the
first layer or the second layer may include other components such
as the above-described active energy ray polymerizable compound, a
radical initiator, a tackifier, a moisture scavenger, a moisture
blocker, a dispersant or a silane compound as well as the
above-described resin, and the components of the first and second
layers may be the same as or different from each other. Also, the
second layer may include a curable material, a curing agent, or a
filler in a suitable range of content depending on a desired
physical property. Meanwhile, the content of the moisture scavenger
may be controlled depending on a damage of the element by
considering the fact that the encapsulation film is applied in
encapsulating the organic electronic element. For example, a small
amount of or no moisture scavenger may be included in the layer in
contact with the element. In an exemplary embodiment, the second
layer in contact with the element may include the moisture
scavenger at 0 to 20% of the total mass of the moisture scavenger
contained in the encapsulation film. Also, the first layer not in
contact with the element may include the moisture scavenger at 80
to 100% of the total mass of the moisture scavenger contained in
the encapsulation film.
[0053] A sequence of stacking the second layer and the first layer
additionally stacked is not particularly limited. For example, the
second layer may be formed on the first layer, or on the contrary,
the first layer may be formed on the second layer. Also, the
encapsulation film may be composed of three or more layers. For
example, two or more of the first layers may be included, or two or
more of the second layers may be included.
[0054] In an exemplary embodiment, the first layer may have an
elastic portion calculated by General Equation 1 of 30 to 80%, and
the second layer may have an elastic portion calculated by General
Equation 2 of 8 to 40%.
Ep(unit:%)=100.times..sigma.2/.sigma.1 [General Equation 2]
[0055] In General Equation 2, .sigma.1 is the maximum stress value
measured when 30% of stain is applied to the film by applying a
normal force of about 200 gf at 85.degree. C. using a parallel
plate having a diameter of 8 mm in a stress relaxation test mode of
an advanced rheometric expansion system (ARES) while the
pressure-sensitive adhesive layer is formed to a thickness of 600
.mu.m, and .sigma.2 is a stress value measured after the state in
which the strain is applied to the film is maintained for 180
seconds. Specifically, the pressure-sensitive adhesive layer is
first formed to a thickness of 600 .mu.m, and a stress relaxation
test mode of the advanced rheometric expansion system (ARES) is
used. Here, a normal force of about 200 gf is applied at 85.degree.
C. using a parallel plate having a diameter of 8 mm. .sigma.1 is
the maximum stress value measured when 30% of strain is applied to
the film, and .sigma.2 is a stress value measured after the state
in which the strain is applied to the film is maintained for 180
seconds.
[0056] As described above, the encapsulation film may be applied to
encapsulate or capsulate the OED such as an OLED. The encapsulation
film exhibiting the value (Ep) range may be formed in an
encapsulating or capsulating structure with excellent durability
without generating air bubbles under a high temperature durability
test condition when applied to an encapsulation or capsulation
process. In an exemplary embodiment, the encapsulation film may be
used, as will be described later, to form the encapsulating or
capsulating structure covering the top and side surfaces of an
element of the OED.
[0057] The term "advanced rheometric expansion system (ARES)" is a
rheometer evaluating viscoelastic properties such as viscosity,
shear modulus, loss factor and storage modulus of a material. The
instrument is a mechanical measuring device that can apply dynamic
and normal states to a sample and measure a transfer torque to an
extent that the sample is resistant to the stress applied as
described above.
[0058] In an exemplary embodiment, the encapsulation film of the
present application may be directly attached to a metal layer on
the first layer of the pressure-sensitive adhesive layer. The term
"directly attached" used herein may mean that there is no layer
between two layers. Also, the second layer may be attached to a
substrate on which an element is formed to entirely seal the
element. That is, the second layer may be directly attached to the
substrate.
[0059] In an exemplary embodiment, the value Ep calculated by
General Equation 2 as described above of the first layer of the
exemplary encapsulation film may be 30 to 80%, 30 to 75% or 30 to
70%. Also, the value Ep calculated by General Equation 2 as
described above of the second layer may be 8 to 40%, 10 to 40% or
20 to 40%. In the present application, the adhesive durability and
reliability of the first layer may be excellently maintained by
controlling the Ep value within the above range by considering that
the first layer is directly attached to the metal layer. Also, in
the present application, the lamination quality between the
substrate and the encapsulation film of the second layer may be
achieved by controlling the Ep value within the above range. The
value of the elastic portion of the first layer according to the
present application may be the same as or higher than the value of
the elastic portion of the second layer, but the present
application is not limited thereto.
[0060] In an exemplary embodiment of the present application, the
first layer may have a probe tack force measured according to ASTM
D2979 within a range of 50 to 500 gf, and specifically, the first
layer may have a probe tack force of 60 to 450 gf or 70 to 400 gf.
Also, the second layer may have a probe tack force measured
according to ASTM D2979 within a range of 3 to 100 gf, and
specifically, the second layer may have a probe tack force of 3 to
90 gf.
[0061] Also, while formed to a thickness of 100 .mu.m, the
pressure-sensitive adhesive layer of the encapsulation film
according to the present application may have a water vapor
transmission rate (WVTR) of 50, 40, 30, 20 or 10 g/m.sup.2day or
less, which is measured in a thickness direction of the film at
100.degree. F. and a relative humidity of 100%. As the composition
or crosslinking condition of the pressure-sensitive adhesive are
adjusted to have such a WVTR, when the pressure-sensitive adhesive
is applied to the encapsulation or capsulation structure of the
electronic device, the encapsulation or capsulation structure may
effectively block moisture or oxygen permeated from the outside and
thus stably protect the element. As the WVTR is lower, a more
excellent moisture blocking property may be exhibited, and
therefore, the lower limit may be, but is not particularly limited
to, for example, 0 g/m.sup.2day.
[0062] In an exemplary embodiment of the present application, the
encapsulation film may further include a metal layer. The metal
layer according to an exemplary embodiment of the present
application may be transparent or opaque. The metal layer may be
formed by depositing metal on a thin metal foil or a polymer base
film. For the metal layer, any material having thermal conductivity
and a moisture blocking property may be used 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 blend thereof. For example, the metal layer may
include an alloy of two or more metals, for example, an iron-nickel
alloy. Also, in one example, the metal layer may include a metal
oxide such as silicon oxide, aluminum oxide, titanium oxide, indium
oxide, tin oxide, tin indium oxide, tantalum oxide, zirconium
oxide, niobium oxide or a blend thereof. The metal layer may be
deposited using a means for electrolysis, rolling, heated
evaporation, electron beam evaporation, sputtering, reactive
sputtering, chemical vapor deposition, plasma chemical vapor
deposition or electron cyclotron resonance plasma source chemical
vapor deposition. In one exemplary embodiment of the present
application, the metal layer may be deposited by reactive
sputtering.
[0063] Preferably, 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. Due to the high thermal
conductivity, heat generated at a laminating interface in a process
of laminating the metal layer may be more rapidly emitted. Also,
because of the high thermal conductivity, heat accumulated in the
operation of the OED may be quickly emitted to an outside, and thus
a temperature of the OED itself may be maintained lower, and cracks
and defects may be reduced.
[0064] The term "thermal conductivity" used herein may be a degree
of the ability to transfer heat by conduction, and the unit may be
W/mK. The unit is a degree of heat transmission of a material at
the same temperature and distance, and refers to the unit (watt) of
heat with respect to the unit (meter) of a distance and the unit
(kelvin) of a temperature.
[0065] The pressure-sensitive adhesive layer of the exemplary
encapsulation film may satisfy General Equation 1 shown below.
Also, the above-described metal layer may be further included.
d.ltoreq.1 mm [General Equation 1]
[0066] In General Equation 1, d is a creeping distance of the
pressure-sensitive adhesive layer creeped behind when a sample
prepared by forming the pressure-sensitive adhesive layer having a
thickness of 50 .mu.m on one surface of a metal base is attached to
a glass in an adhesive area of 1 cm.times.1 cm, and 500 g of a
weight is loaded to the metal base at 85.degree. C. for 1 hour.
Here, the metal base may be formed of copper, aluminum, nickel,
invar or stainless steel (SUS). In detail, the surface of the
pressure-sensitive adhesive layer of the laminate sample including
the pressure-sensitive adhesive layer and the metal base may be
attached to the glass in an area of 1 cm.times.1 cm, and a weight
may be loaded to the metal base as described above. The creeping
distance of the pressure-sensitive adhesive layer may be measured
in a distance of the movement of the metal base. In the general
equation, d may be 1 mm or less, for example, 990 .mu.m or less,
950 .mu.m or less, 800 .mu.m or less, 700 .mu.m or less, 600 .mu.m
or less, or 400 .mu.m or less.
[0067] Also, in one example, the pressure-sensitive adhesive layer
of the encapsulation film of the present application may have a
Mooney viscosity (.eta.*) of 5000 to 10.sup.7 Pas measured by a
shear stress using a planar jig having a diameter of 8 mm at a
strain of 5%, a frequency of 1 Hz and any one temperature point in
the range of 30 to 150.degree. C. The Mooney viscosity may be
measured by a known method, for example, an ARES (TA). The range of
the viscosity may be, for example, 5,000 to 10.sup.7 Pas, 5,000 to
10.sup.6 Pas or 5,000 to 5.times.10.sup.5 Pas. The metal layer may
be further included on one surface of the pressure-sensitive
adhesive layer satisfying the viscosity range. The
pressure-sensitive adhesive layer satisfying the viscosity range
may include the above-described compound of Formula 1 or active
energy ray polymerizable compound.
[0068] The encapsulation film may further include a base film or
release film (hereinafter, probably referred to as a "first film"),
and have a structure in which the pressure-sensitive adhesive is
formed on the base or release film. Also, the structure may further
include a base or release film formed on the pressure-sensitive
adhesive (hereinafter, also referred to as a "second film").
[0069] FIGS. 1 and 2 are cross-sectional views of an encapsulation
film according to an exemplary embodiment of the present
application.
[0070] As shown in FIG. 1, the encapsulation film of the present
application may include a pressure-sensitive adhesive layer 12 and
a metal layer 13, which are formed on a base film or release film
11. Also, FIG. 2 shows the pressure-sensitive adhesive layer 12
including a first layer 12a and a second layer 12b.
[0071] A specific type of the first film capable of being used in
the present application is not particularly limited. In the present
application, as the first film, for example, a general polymer film
used in the art may be used. In the present application, for
example, as the base or release film, a polyethyleneterephthalate
film, a polytetrafluoroethylene film, a polyethylene film, a
polypropylene film, a polybutene film, a polybutadiene film, a
vinyl chloride copolymer film, a polyurethane film, an
ethylene-vinyl acetate film, an ethylene-propylene copolymer film,
an ethylene-acrylic acid ethyl copolymer film, an ethylene-acrylic
acid methyl copolymer film or a polyimide film may be used. Also,
one or both surfaces of the base film or release film of the
present application may be treated with a suitable releasing
treatment. As an example of a releasing agent used for the
releasing treatment of the base film, an alkyde-, silicon-,
fluorine-, unsaturated ester-, polyolefin- or wax-based agent may
be used, and for the thermal resistance, an alkyde-, silicon- or
fluorine-based releasing agent may be used, but the present
application is not limited thereto.
[0072] In the present application, the thickness of the base film
or release film (the first film) is not particularly limited, and
may be suitably selected according to use. For example, in the
present application, the thickness of the first film may be about
10 to 500 .mu.m, and preferably about 20 to 200 .mu.m. When the
thickness is less than 10 .mu.m, the base film may be easily
deformed in the manufacturing process, and when the thickness is
more than 500 .mu.m, economic feasibility is reduced.
[0073] A thickness of the pressure-sensitive adhesive layer
included in the encapsulation film of the present application is
not particularly limited, and may be suitably selected according to
the following condition by considering the use of the film. The
thickness of the pressure-sensitive adhesive layer may be about 5
to 200 .mu.m, and preferably about 5 to 100 .mu.m. When the
thickness of the pressure-sensitive adhesive layer is less than 5
.mu.m, a sufficient adhesive property may not be ensured, and a
rate of the loss of a moisture blocking ability during the process
may be increased. When the thickness is more than 200 .mu.m, it is
difficult to ensure processability, a space exposed to the side
surface may expand so that the moisture blocking property may be
degraded, the thermal resistance may be degraded, and the economic
feasibility may be deceased.
[0074] The present application also relates to a method of
manufacturing an encapsulation film. The exemplary encapsulation
film may be manufactured by molding the pressure-sensitive adhesive
layer in a film or sheet shape.
[0075] In an exemplary embodiment, the method may include applying
a coating solution including a component constituting the
above-described pressure-sensitive adhesive layer to a base or
release film in a sheet or film shape, and drying the applied
coating solution.
[0076] The coating solution may be prepared by dissolving or
dispersing the component of each pressure-sensitive adhesive layer
described above in a suitable solvent. In an exemplary embodiment,
the pressure-sensitive adhesive layer may be prepared by dissolving
or dispersing the moisture scavenger or filler in a solvent when
needed, and mixing the moisture scavenger or filler with an
encapsulation resin after grinding.
[0077] A type of the solvent used in the preparation of the coating
solution is not particularly limited. However, when a dry time of
the solvent is too much longer or drying at a high temperature is
needed, problems in terms of workability or durability of the
encapsulation film may occur, and therefore a solvent having a
volatile temperature of 150.degree. C. or less may be used. In
consideration of film moldability, a small amount of a solvent
having the above range or more of a volatilizing temperature may be
mixed. As the solvent, one or two or more of methylethylketone
(MEK), acetone, toluene, dimethylformamide (DMF), methylcellosolve
(MCS), tetrahydrofuran (THF), xylene and N-methylpyrrolidone (NMP)
may be used, but the present application is not limited
thereto.
[0078] A method of applying the coating solution to the base or
release film is not particularly limited, and thus may be, for
example, a known coating method such as knife coating, roll
coating, spray coating, gravure coating, curtain coating, comma
coating or lip coating.
[0079] The applied coating solution is dried, the solvent is
volatilized, and thus a pressure-sensitive adhesive layer may be
formed. The drying may be performed, for example, at 70 to
150.degree. C. for 1 to 10 minutes. The drying condition may be
changed by considering the used solvent.
[0080] A method of stacking a first layer and a second layer is not
particularly limited. For example, the first layer and the second
layer, which are formed on respective release films, may be
laminated, thereby forming a multi-layered encapsulation film, or
the second layer may be formed directly on the first layer and vice
versa.
[0081] After drying, a metal layer may be formed on the
pressure-sensitive adhesive layer. A method of forming the metal
layer may be a technique known in the art. For example, the metal
layer may be formed of metal foil, or formed by depositing a metal
on a polymer base. For example, the metal layer may be formed by
electrolysis or rolling.
[0082] The present application also relates to an OED. The OED may
include a substrate; an organic electronic element formed on the
substrate; and an encapsulation film encapsulating entire surfaces,
for example, all of the top and side surfaces of the organic
electronic element. The encapsulation film may include a
pressure-sensitive adhesive layer containing a pressure-sensitive
adhesive composition in a crosslinked state. Also, the
encapsulation film may further include a metal layer formed on the
pressure-sensitive adhesive layer.
[0083] Here, the organic electronic element may be, for example, an
organic light emitting element.
[0084] Also, the present application relates to a method of
manufacturing an OED. The OED may be manufactured using, for
example, the encapsulation film.
[0085] The pressure-sensitive adhesive layer may be formed for a
structure exhibiting an excellent moisture blocking property in the
OED, and effectively fixing and supporting the substrate and the
metal layer.
[0086] In addition, the pressure-sensitive adhesive layer may be
formed to be stable regardless of a type of the OED, for example, a
top emission or bottom emission type.
[0087] The term "pressure-sensitive adhesive layer" used herein may
be a pressure-sensitive adhesive covering all of the top and side
surfaces of the organic electronic element.
[0088] FIG. 3 is a schematic diagram of an exemplary OED, in which
an organic electronic element is an organic light emitting
element.
[0089] To manufacture the OED, for example, applying the
above-described encapsulation film to the substrate on which the
organic electronic element is formed to cover the entire surfaces
of the organic electronic element; and curing the encapsulation
film may be used.
[0090] The term "curing" used herein may refer to preparation of a
pressure-sensitive adhesive by crosslinking the pressure-sensitive
adhesive composition of the present application through heating or
UV irradiation.
[0091] In detail, the organic electronic element may be formed by
forming a transparent electrode on a glass or polymer film used as
a substrate through vacuum deposition or sputtering, forming a
light emitting organic material layer, for example, consisting of a
hole transport layer, an emitting layer and an electron transport
layer on the transparent electrode, and further forming an
electrode layer thereon. Subsequently, the pressure-sensitive
adhesive layer of the encapsulation film is disposed to cover the
entire surfaces of the organic electronic element of the substrate,
which has gone through the above-described process.
[0092] In an exemplary embodiment, as shown in FIG. 3, a product
for encapsulating an OED may be disposed such that the
pressure-sensitive adhesive layer 12 of the encapsulation film is
disposed to be in contact with an OED 22 and a substrate 21. Also,
the metal layer 13 may be disposed on the pressure-sensitive
adhesive layer 12.
Effect
[0093] The present application provides a pressure-sensitive
adhesive composition, which can form a structure for effectively
blocking moisture or oxygen entering an OED from the outside and
has an excellent heat retention under a high-temperature and
high-humidity condition, and an encapsulation film including the
same.
BRIEF DESCRIPTION OF THE DRAWINGS
[0094] FIGS. 1 and 2 are cross-sectional views of an encapsulation
film according to an exemplary embodiment of the present
application; and
[0095] FIG. 3 is a cross-sectional view of an OED according to an
exemplary embodiment of the present application.
EXPLANATION OF REFERENCE NUMERALS
[0096] 11: base film or release film [0097] 12: pressure-sensitive
adhesive layer [0098] 12a: first layer [0099] 12b: second layer
[0100] 13: metal layer [0101] 21: substrate [0102] 22: organic
electronic device
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0103] Hereinafter, the present application will be described in
further detail with reference to examples according to the present
application and comparative examples not according to the present
application, and the scope of the present application is not
limited to the examples as follows.
Example 1
[0104] A coating solution was prepared by adding 50 g of butyl
rubber (Br068, EXXON) as a polymer derived from butylene, 24 g of a
hydrogenated hydrocarbon resin (Eastotac H-100L) as a tackifier, 15
g of a monofunctional acrylate, i.e., 2-(2-ethoxyethoxy)ethyl
acrylate as the compound of Formula 1, 10 g of trimethylolpropane
triacrylate as a multifunctional active energy ray polymerizable
compound and 1 g of 2,2-dimethoxy-1,2-diphenylethane-1-one
(Irgacure 651, Ciba) as a radical initiator, and diluting the
resultant mixture with toluene to have a solid content of about 15
wt %.
[0105] An encapsulation film was formed by forming a
pressure-sensitive adhesive layer to a thickness of 50 .mu.m by
coating a release surface of a release PET with the prepared
solution and drying the coated product in an oven at 100.degree. C.
for 15 minutes, and laminating the pressure-sensitive adhesive
layer with a copper film having a thickness of 20 .mu.m. Physical
properties of the film sample irradiated with UV rays at 2
J/cm.sup.2 were measured.
Example 2
[0106] An encapsulation film was formed by the same method as
described in Example 1, except that the compound of Formula 1 was
replaced with stearyl acrylate.
Example 3
[0107] An encapsulation film was formed by the same method as
described in Example 1, except that the compound of Formula 1 was
replaced with lauryl acrylate.
Example 4
[0108] An encapsulation film was formed by the same method as
described in Example 1, except that the compound of Formula 1 was
replaced with isodecyl acrylate.
Comparative Example 1
[0109] An encapsulation film was formed by the same method as
described in Example 1, except that the compound of Formula 1 was
not included.
Comparative Example 2
[0110] An encapsulation film was formed by the same method as
described in Example 1, except that the compound of Formula 1 was
replaced with lauryl methacrylate.
Comparative Example 3
[0111] An encapsulation film was formed by the same method as
described in Example 1, except that the compound of Formula 1 was
replaced with isobornyl acrylate.
Experimental Example 1
Non-Lamination of Panel
[0112] The pressure-sensitive adhesive layer having a thickness of
50 .mu.m and a size of 14 cm.times.9 cm, which was formed in any
one of Examples and Comparative Examples, was attached to the
center of a 0.7 T glass having a size of 150 cm.times.10 cm using a
roll laminator. A glass having the same size as the prepared
specimen was laminated through vertical pressing using a vacuum
laminator at 25 to 100.degree. C. and a vacuum degree of 100 pa
under a pressure of 0.5 MPa. A laminating property was determined
by the degree of non-lamination or bubble generation on the entire
surfaces of a pressure-sensitive adhesive, and thus when
non-lamination or generation of at least one bubble having a
diameter of 3 mm or more occurred, it was determined as a
lamination failure.
Experimental Example 2
Creeping Distance
[0113] A sample prepared by forming the pressure-sensitive adhesive
layer prepared in any one of Examples and Comparative Examples on
one surface of a metal base having a thickness of 50 .mu.m was
attached to a glass at an adhesive area of 1 cm.times.1 cm, 500 g
of a weight was loaded to the metal base in a gravity direction at
85.degree. C. for 1 hour, and then a creeping distance of the
pressure-sensitive adhesive layer was measured. Here, as the metal
base, copper was used. When the weight was loaded, the case in
which the adhesive area was all creeped, the thus the sample was
detached was determined as a failure.
TABLE-US-00001 TABLE 1 85.degree. C. retention, creeping Lamination
or non- distance (.mu.m) lamination of panel Example 1 0 X Example
2 960 X Example 3 500 X Example 4 100 X Comparative failed
Lamination failed Example 1 Comparative failed X Example 2
Comparative failed Lamination failed Example 3
[0114] Since Comparative Examples 1 and 3 did not include the
compound of Formula 1, it is shown that the heat retention is
decreased at high temperature, and panel lamination is failed.
Also, in Comparative Example 2, lauryl methacrylate is included in
the pressure-sensitive adhesive composition, and a UV curing rate
is delayed due to a steric hindrance effect of a methyl group,
resulting in degradation of thermal resistance.
* * * * *