KR102212139B1 - The temperature variable adhesive sheet and method for preparing adhesive sheet using the same - Google Patents

Abstract

The present specification provides a temperature-variable pressure-sensitive adhesive sheet and a method of manufacturing a temperature-variable pressure-sensitive adhesive sheet using the same.

Description

Temperature variable adhesive sheet and method of manufacturing temperature variable adhesive sheet using the same {THE TEMPERATURE VARIABLE ADHESIVE SHEET AND METHOD FOR PREPARING ADHESIVE SHEET USING THE SAME}

The present specification relates to a temperature-variable pressure-sensitive adhesive sheet and a method of manufacturing a temperature-variable pressure-sensitive adhesive sheet using the same.

An organic electronic device (OED) refers to a device including an organic material layer that generates an exchange of charges using holes and electrons, and examples thereof include a photovoltaic device, a rectifier, and And a transmitter and an organic light emitting diode (OLED).

Among the organic electronic devices, an organic light emitting diode (OLED) consumes less power, has a faster response speed, and is advantageous in reducing the thickness of a display device or lighting compared to a conventional light source. In addition, OLED has excellent space utilization, and is expected to be applied in various fields ranging from various portable devices, monitors, notebooks and TVs.

In the commercialization and expansion of OLED use, the most important problem is durability. Organic materials and metal electrodes included in OLEDs are very easily oxidized by external factors such as moisture. Therefore, products containing OLED are highly sensitive to environmental factors. Accordingly, various methods have been proposed to effectively block the penetration of oxygen or moisture from the outside into an organic electronic device such as OLED.

Patent Document 1 is an adhesive encapsulation composition film and an organic electroluminescent device, which is an adhesive based on PIB (polyisobutylene), which has poor processability and poor reliability under high temperature and high humidity conditions.

Accordingly, there is a need to develop an encapsulant having excellent optical properties and reworkability while securing a required life in an organic electronic device and effectively blocking moisture penetration, maintaining reliability under high temperature and high humidity conditions.

Republic of Korea Patent Publication No. 2008-0088606

In the present specification, to provide a temperature-variable pressure-sensitive adhesive sheet and a method of manufacturing a temperature-variable pressure-sensitive adhesive sheet using the same.

An exemplary embodiment of the present specification is an adhesive sheet in which a first adhesive layer and a second adhesive layer are sequentially provided on a barrier film,

The second adhesive layer includes at least one adhesive resin selected from olefin-based, urethane-based, acrylic-based, and silicone-based, and 50 parts by weight or more of an acetyltributyl citrate (ATBC) plasticizer based on 100 parts by weight of the adhesive resin and 80 parts by weight And polydimethylsiloxane (PDMS) 0.005 parts by weight or more and 0.5 parts by weight or less,

It provides a pressure-sensitive adhesive sheet having an initial adhesive strength of 200 gf/in or less between the second pressure-sensitive adhesive layer and the SUS304 substrate, and an adhesive strength of 400 gf/in or more after 20 minutes at 70°C and 5 atm.

Another exemplary embodiment of the present specification provides an organic electronic device encapsulation product including the above-described adhesive sheet.

Another exemplary embodiment of the present specification is preparing a barrier film; And

It provides a method of manufacturing a pressure-sensitive adhesive sheet comprising the step of forming the pressure-sensitive adhesive sheet on the barrier film.

In the present specification, the pressure-sensitive adhesive sheet according to an exemplary embodiment maintains the characteristics of a conventional pressure-sensitive adhesive sheet such as adhesive properties, and characteristically has an advantage of being able to rework in case of incorrect attachment due to low initial adhesive strength.

1 shows an adhesive sheet according to an exemplary embodiment of the present specification.

When a member is referred to herein as being “on” another member, this includes not only the case where a member is in contact with another member, but also the case where another member exists between the two members.

In the present specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

Hereinafter, the present specification will be described in more detail.

An exemplary embodiment of the present specification is an adhesive sheet in which a first adhesive layer and a second adhesive layer are sequentially provided on a barrier film, and the second adhesive layer is selected from olefin-based, urethane-based, acrylic-based, and silicone-based. Including at least one type of adhesive resin, and 50 parts by weight or more and 80 parts by weight or less of an acetyltributyl citrate (ATBC) plasticizer and 0.005 parts by weight or more and 0.5 parts by weight or less of polydimethylsiloxane (PDMS) based on 100 parts by weight of the adhesive resin It provides an adhesive sheet having an initial adhesive strength of 200 gf/in or less between the second adhesive layer and the SUS304 substrate, and an adhesive strength of 400 gf/in or more after 20 minutes at 70° C. and 5 atm.

According to the exemplary embodiment of the present specification, the barrier film may have a structure in which a base layer, a planarization layer, and a barrier layer are stacked.

According to the exemplary embodiment of the present specification, the first pressure-sensitive adhesive layer may be provided on the barrier layer of the barrier film.

The type of the base film used as the base layer is not particularly limited, and a known base film may be applied. For example, as the base film, various plastic films may be used. Plastic films include polyester film, acetate resin film, polyethersulfone film, polycarbonate film, polyamide film, polyimide film, polyolefin film, acrylic film, polyvinyl chloride film, polyvinylidene chloride film, polystyrene film, poly A vinyl alcohol film, a polyarylate film, or a polyphenylene sulfide film may be used. The thickness of the base film is also not particularly limited, and may be adjusted to an appropriate thickness in consideration of the use of the laminate. In general, the base film may have a thickness of 10 μm to 110 μm, 10 μm to 80 μm, 10 μm to 60 μm, or 10 μm to 30 μm.

In the pressure-sensitive adhesive sheet according to an exemplary embodiment of the present specification, the second pressure-sensitive adhesive layer includes one or more pressure-sensitive adhesive resins selected from olefin-based, urethane-based, acrylic-based, and silicone-based, and acetyltributyl citrate based on 100 parts by weight of the adhesive resin. It may contain 50 parts by weight to 80 parts by weight or less of the plasticizer, more preferably 55 parts by weight or more and 70 parts by weight or less. By adding a plasticizer to the curable composition, the viscosity or slump property of the curable composition, and mechanical properties such as hardness, tensile strength, and elongation of the cured product obtained by curing the curable composition can be adjusted.

In the pressure-sensitive adhesive sheet according to an exemplary embodiment of the present specification, the second pressure-sensitive adhesive layer includes one or more pressure-sensitive adhesive resins selected from olefin-based, urethane-based, acrylic-based and silicone-based, and 0.005 polydimethylsiloxane based on 100 parts by weight of the adhesive resin. It may be included in an amount of 0.5 parts by weight or more, and preferably 0.05 parts by weight or more and 0.1 parts by weight or less.

According to another exemplary embodiment of the present specification, BYK-377 (BYK) or OFX-0400 (Dow Corning) may be used as the polydimethylsiloxane.

By adding polydimethylsiloxane, low viscosity and plasticizing effects can be expected, low-temperature workability can be improved, and effects such as improvement of chinability on the surface of the cured product and control of mechanical properties can be expected.

In addition, when the content range of the plasticizer and the polydimethylsiloxane as described above is satisfied at the same time, the initial peeling force is low, and the variable property of increasing the peeling force after the variable is realized, and the reliability is also good.

In the adhesive sheet according to an exemplary embodiment of the present specification, the initial adhesive strength between the second adhesive layer and the SUS304 substrate may be 5 gf/in or more and 200 gf/in or less, preferably 15 gf/in or more and 150 gf/in or less. And, due to the low initial adhesive strength as described above, it is possible to rework in case of incorrect attachment.

In the pressure-sensitive adhesive sheet according to an exemplary embodiment of the present specification, the adhesive strength after 20 minutes at 70° C. and 5 atm after application of the second pressure-sensitive adhesive layer is 400 gf/in or more and 1500 gf/in or less, and preferably 500 gf /in or more and 1300 gf/in or less.

An autoclave may be used by heat treatment of the second adhesive layer at 70° C. and 5 atm. By performing the autoclave applying heat and pressure at the same time as described above, the compression efficiency can be increased.

According to an exemplary embodiment of the present specification, the initial adhesive strength is 300mm with a TA (Texture Analyze) equipment after 20 minutes after removing the release film attached to the second adhesive layer and laminating the SUS304 substrate with a 1 inch long roll of 2 kg load. It can be measured at a speed of /min and an angle of 180 degrees.

According to an exemplary embodiment of the present specification, the adhesive strength after the autoclave is laminated on a SUS304 substrate with a roll of 1 inch in length and a load of 2 kg, and then autoclaved at a speed of 300 mm/min and a 180 degree angle with a TA (Texture Analyze) equipment. Peel force can be measured.

The pressure-sensitive adhesive sheet according to an exemplary embodiment of the present specification may have a moisture transmittance of 10 g/m ² ·24h or less. Within the above range, the pressure-sensitive adhesive sheet may implement a structure capable of stably protecting a device by effectively blocking moisture or oxygen penetrating from the outside. The lower the moisture permeability, the better the moisture barrier property can be, so the lower limit is not particularly limited, but may be, for example, 0 g/m ² ·24h.

In the present specification, the moisture transmittance in the thickness direction of the film-shaped layer can be measured in a state where a nylon mesh is attached to the film-shaped adhesive layer and placed at 100°F and 100% relative humidity, The moisture permeability can be measured according to the regulations in ASTM F1249.

According to the exemplary embodiment of the present specification, the first pressure-sensitive adhesive layer may include a copolymer of diene and an olefin-based compound including one carbon-carbon double bond.

Here, the olefin-based compound may include isobutylene, propylene, or ethylene, and the diene may be a monomer polymerizable with the olefin-based compound, for example, 1-butene, 2-butene, isoprene or butadiene. It may include. That is, a homopolymer of an isobutylene monomer; A copolymer obtained by copolymerizing an isobutylene monomer and another polymerizable monomer; Or a mixture of these and the like can be used. In one example, the copolymer of the olefin-based compound and dienes including one carbon-carbon double bond may be a butyl rubber.

By using a specific resin as described above, the moisture barrier property to be implemented in the present invention can be satisfied. In addition, the present invention can improve moisture resistance and heat resistance as compared to a conventional isobutylene polymer having low moisture permeability but also low heat resistance.

According to another exemplary embodiment of the present specification, the first pressure-sensitive adhesive layer may further include a tackifier and a curable resin.

The tackifier may be preferably a hydrogenated cyclic olefin-based polymer. As the tackifier, a hydrogenated petroleum resin obtained by hydrogenating a petroleum resin can be used, for example. Hydrogenated petroleum resins can be partially or fully hydrogenated and can also be mixtures of such resins. These tackifiers can be selected having good compatibility with the pressure-sensitive adhesive composition, excellent moisture barrier properties, and low organic volatile components. Specific examples of the hydrogenated petroleum resin include a hydrogenated terpene resin, a hydrogenated ester resin, or a hydrogenated dicyclopentadiene resin. The weight average molecular weight of the tackifier may be about 200 to 5,000. The content of the tackifier may be appropriately adjusted as necessary.

In the present specification, the term weight average molecular weight may mean a conversion value for standard polystyrene measured by GPC (Gel Permeation Chromatograph), and unless otherwise specified, the molecular weight of any polymer is the weight average molecular weight of the polymer. It can mean.

For example, the tackifier may be included in a ratio of 5 parts by weight to 100 parts by weight, 8 to 95 parts by weight, 10 parts by weight to 93 parts by weight, or 15 parts by weight to 90 parts by weight based on 100 parts by weight of the solid content of the pressure-sensitive adhesive composition. have.

The curable resin is, for example, cured to exhibit adhesive properties, and includes at least one thermosetting functional group such as a glycidyl group, an isocyanate group, a hydroxy group, a carboxyl group or an amide group, or an epoxide group , A cyclic ether group, a sulfide group, an acetal group, or a lactone group. It may include a curable resin including one or more functional groups curable by irradiation of electromagnetic waves. In addition, specific types of resins as described above may include acrylic resins, polyester resins, isocyanate resins, epoxy resins, etc., but are not limited thereto.

In the present invention, as the curable resin, aromatic or aliphatic; Alternatively, a linear or branched epoxy resin may be used. In one embodiment of the present invention, an epoxy resin containing two or more functional groups and having an epoxy equivalent of 180 g/eq to 1,000 g/eq may be used. By using an epoxy resin having an epoxy equivalent in the above range, properties such as adhesion performance and glass transition temperature of the cured product can be effectively maintained. Examples of such epoxy resins include cresol novolac epoxy resin, bisphenol A type epoxy resin, bisphenol A type novolac epoxy resin, phenol novolac epoxy resin, tetrafunctional epoxy resin, biphenyl type epoxy resin, triphenol methane type Epoxy resins, alkyl-modified triphenol methane epoxy resins, naphthalene-type epoxy resins, dicyclopentadiene-type epoxy resins, or dicyclopentadiene-modified phenol-type epoxy resins, or a mixture of two or more kinds thereof.

According to the exemplary embodiment of the present specification, the second pressure-sensitive adhesive layer may include a pressure-sensitive adhesive composition including at least one selected from olefin-based, urethane-based, acrylic-based, and silicone-based adhesive polymers.

In the present specification, the acrylic polymer may mean a polymer including an acrylic monomer as a polymerization unit. In the present specification, the term polymerization unit may mean a form in which a certain monomer forms a part of an adhesive polymer through a polymerization reaction.

In the above, the acrylic monomer means acrylic acid, methacrylic acid, or a derivative thereof. The acrylic polymer may be included as a main component in the pressure-sensitive adhesive layer.

The term main component herein includes 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, or 95% or more of the component by weight. Means the case. In the above, the upper limit of the weight ratio of the main component is not particularly limited, and may be, for example, less than 100%.

According to the exemplary embodiment of the present specification, the polymer included in the pressure-sensitive adhesive composition may include a polymerization unit of an alkyl (meth)acrylate, a hard comonomer, and a crosslinkable monomer.

In the above, alkyl (meth)acrylate is the main component of the polymer, and therefore the weight ratio of the polymerized unit in the polymer is 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more , 85% or more, 90% or more, or 95% or more.

As the alkyl (meth)acrylate, a single polymer having a glass transition temperature of -80°C to -30°C can be used. In the present specification, the term glass transition temperature of a single polymer may mean a glass transition temperature of a homopolymer prepared using a corresponding monomer. Any type of alkyl (meth)acrylate may be used as long as the glass transition temperature of the single polymer is within the above range. For example, an alkyl (meth)acrylate having an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms may be used. In the above, the alkyl group may be linear, branched or cyclic. Such monomers include n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, sec-butyl (meth)acrylate, pentyl ( Meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate or Lauryl (meth) acrylate and the like may be exemplified, and one or more of the above may be selected and used.

In the present specification, the term (meth)acrylic means acrylic or methacrylic.

In the present specification, the term hard comonomer refers to a monomer that can be copolymerized with the alkyl (meth)acrylate, and the glass transition temperature of the single polymer of the monomer is in the range of 85°C to 130°C. . The single polymer glass transition temperature of the hard comonomer may be 125°C or less, 120°C or less, 115°C or less, or about 110°C or less in another example. Such comonomers include isobornyl (meth)acrylate, vinyl pyrrolidone, hydroxyalkylacrylamide (in the above, the number of carbon atoms of the alkyl is 1 to 4), tertiarylbutyl (meth) acrylate acrylate), dihydrodicyclopentadienyl acrylate (DCPA, dihydrodicyclopentadienyl acrylate), N-vinylformamide (VFA, N-vinylformamide), cyclohexyl (meth)acrylate (CHMA, cyclohexyl methacrylate), acrylamide, benzyl (Meth)acrylate, tert-butyl acrylate, iso-butyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, cyclopropyl acrylate, cyclobutyl acrylate, N,N-dimethyl (meth )Acrylamide, N,N-diphenyl methacrylamide, N-(n-dodecyl)methacrylamide, 1-hexadecyl methacrylate, 2-methoxyethyl methacrylate, methyl methacrylate, N- Naphthyl acrylate, 2-phenoxyethyl methacrylate, phenyl (meth)acrylate, 2-phenylethyl (meth)acrylate, n-propyl methacrylate, styrene, methyl acrylate, dicyclopentanyl methacrylate (dicyclopentanyl) ester, N-vinyl caprolactam, N-hydroxyethyl acrylamide, and the like may be exemplified, but are not limited thereto.

The hard comonomer may be included in the polymer in a ratio of 5 to 50 parts by weight based on 100 parts by weight of the alkyl (meth)acrylate. In another example, the ratio may be 7 parts by weight or more, 9 parts by weight or more, or 10 parts by weight or more. In another example, the ratio may be 45 parts by weight or less, 40 parts by weight or less, or 38 parts by weight or less. Under such a ratio, the pressure-sensitive adhesive layer may exhibit appropriate peel strength characteristics.

According to an exemplary embodiment of the present specification, the crosslinkable monomer may be a monomer having a crosslinkable functional group, and if it is capable of providing a crosslinkable functional group to the polymer produced by polymerization with the alkyl (meth)acrylate monomer, special Can be selected without limitation.

According to an exemplary embodiment of the present specification, the pressure-sensitive adhesive composition may include a monomer having a crosslinkable functional group.

According to an exemplary embodiment of the present specification, the crosslinkable functional group may be any one or more selected from the group consisting of a hydroxy group, an isocyanate group, a glycidyl group, an epoxy group, an amine group, and a carboxyl group.

The monomer having a hydroxy group is, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth) ) Hydroxyalkyl (meth)acrylate such as acrylate or 8-hydroxyoxyl (meth)acrylate; Hydroxypolyalkylene glycol (meth)acrylate such as hydroxy polyethylene glycol (meth)acrylate or hydroxypolypropylene glycol (meth)acrylate; Hydroethyl acrylate; There may be such as, but is not limited thereto.

The monomer having a carboxy group is, for example, beta-carboxyethyl acrylate, (meth)acrylic acid, 2-(meth)acryloyloxy acetic acid, and 3-(meth)acryloyloxy propyl acid. , 4-(meth)acryloyloxy butyric acid, acrylic acid duplex, itaconic acid, maleic acid, maleic anhydride, and the like, but are not limited thereto.

The monomer having an amine group is, for example, 2-aminoethyl (meth)acrylate, 3-aminopropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate or N,N-dimethylaminopropyl There may be (meth)acrylate, etc., but is not limited thereto.

Among the monomers having various crosslinkable functional groups, an appropriate type may be selected in consideration of a desired glass transition temperature of the acrylic polymer or reactivity with a crosslinking agent described below.

According to an exemplary embodiment of the present specification, the crosslinkable functional group may be selected without limitation, as long as it can cause a crosslinking reaction with a crosslinking agent to be described later at a temperature in the range of, for example, about 50°C to 300°C.

According to an exemplary embodiment of the present specification, based on 100 parts by weight of the polymer, 55 to 95 parts by weight of the alkyl (meth)acrylate, 1 to 30 parts by weight of a hard comonomer, and 1 to 40 parts by weight of a crosslinkable monomer may be included. .

According to an exemplary embodiment of the present specification, the pressure-sensitive adhesive composition includes a crosslinking agent.

According to another exemplary embodiment of the present specification, a pressure-sensitive adhesive composition having physical properties suitable for application to a foldable display may be provided, including a crosslinking agent having a functional group capable of reacting with a crosslinkable functional group contained in the polymer.

Specifically, the crosslinking agent is at least one selected from the group consisting of an alkoxy silane group, a carboxyl group, an acid anhydride group, a vinyl ether group, an amine group, a carbonyl group, an isocyanate group, an epoxy group, an aziridinyl group, a carbodiimide group and an oxazoline group. It may contain a functional group. The type of the functional group may vary depending on the type of the crosslinkable functional group contained in the polymer or other mechanisms for implementing the crosslinked structure.

The crosslinking agent containing the carboxy group is, for example, o-phthalic acid, isophthalic acid, terephthalic acid, 1,4-dimethylterephthalic acid, 1,3-dimethylisophthalic acid, 5-sulfo-1,3-dimethylisophthalic acid, 4, 4-biphenyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, norbornenedicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid Or aromatic dicarboxylic acids such as phenylindanedicarboxylic acid; Aromatic dicarboxylic acid anhydrides such as phthalic anhydride, 1,8-naphthalenedicarboxylic anhydride or 2,3-naphthalenedicarboxylic anhydride; Alicyclic dicarboxylic acids such as hexahydrophthalic acid; Alicyclic dicarboxylic acid anhydrides such as hexahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, or 1,2-cyclohexanedicarboxylic anhydride; Or oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, suberic acid, maleic acid, chloromaleic acid, fumaric acid, dodecanoic acid, pimelic acid, citraconic acid, glutaric acid, itaconic acid, etc. And aliphatic dicarboxylic acids.

The crosslinking agent containing the acid anhydride group is, for example, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, oxydiphthalic dianhydride, and diphenylsulfone tetracarboxylic dianhydride. , Diphenyl sulfide tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, perylene tetracarboxylic dianhydride, or naphthalene tetracarboxylic dianhydride.

The crosslinking agent containing the vinyl ether group, for example, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, propylene glycol divinyl Ether, dipropylene glycol divinyl ether, tripropylene glycol divinyl ether, neopentyl glycol divinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, glycerin divinyl ether, trimethylol Propanedivinyl ether, 1,4-dihydroxycyclohexanedivinyl ether, 1,4-dihydroxymethylcyclohexanedivinyl ether, hydroquinonedivinyl ether, ethylene oxide modified hydroquinonedivinyl ether, ethylene oxide modified Resorcindivinyl ether, ethylene oxide modified bisphenol A divinyl ether, ethylene oxide modified bisphenol S divinyl ether, glycerin trivinyl ether, sorbitol tetravinyl ether, trimethylolpropane trivinyl ether, pentaerythritol trivinyl ether, pentaeryte Lithol tetravinyl ether, dipentaerythritol hexavinyl ether, dipentaerythritol polyvinyl ether, ditrimethylolpropane tetravinyl ether or ditrimethylolpropane polyvinyl ether.

The crosslinking agent containing the amine group may include, for example, aliphatic diamines such as ethylenediamine or hexamethylenediamine; Alicyclic diamines such as 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexyl, diaminocyclohexane or isophoronediamine Ryu; Alternatively, there may be aromatic diamines such as xylenediamine.

The crosslinking agent containing the isocyanate group is, for example, 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2, 4-tolylenediisocyanate, 2,6-tolylenediisocyanate, 4,4'-toluidinediisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanatebenzene, dianicidindiisocyanate, 4, 4'-diphenylether diisocyanate, 4,4',4''-triphenylmethane triisocyanate, ω,ω-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4- Dimethylbenzene, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylene diisocyanate, xylylene diisocyanate or xylylene diisocyanate, etc. Aromatic polyisocyanates of; Trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butalene diisocyanate, dodecamethylene diisocyanate or 2 Aliphatic polyisocyanates such as ,4,4-tramethylhexamethylene diisocyanate; Or 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexanediisocyanate, 1,4-cyclohexanediisocyanate, methyl-2,4- Alicyclic polyisocyanates such as cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate, 4,4'-methylenebis(cyclohexylisocyanate) or 1,4-bis(isocyanatemethyl)cyclohexane, etc., or There may be a reaction product of one or more of the above polyisocyanates and polyols.

The crosslinking agent containing the epoxy group is, for example, ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N,N,N,N'-tetraglycidyl-1,3- Xylenediamine, or glycerin diglycidyl ether.

According to an exemplary embodiment of the present specification, the pressure-sensitive adhesive composition includes the crosslinking agent, and may perform a crosslinking reaction with a crosslinkable functional group included in the polymer.

According to an exemplary embodiment of the present specification, the crosslinking agent may be included in the composition in a range of 0.001 to 5 parts by weight based on 100 parts by weight of the polymer.

When the content of the crosslinking agent exceeds 5 parts by weight or less than 0.001 parts by weight, the desired storage modulus cannot be achieved at a temperature of -20°C.

According to an exemplary embodiment of the present specification, the pressure-sensitive adhesive composition is a known additional component other than the aforementioned polymer and crosslinking agent, for example, an antistatic agent, a tackifier resin, a curing agent, a UV stabilizer, an antioxidant, a colorant, a reinforcing agent, a filler, an antifoaming agent, an interface It may further include an activator or a plasticizer.

The structure of the pressure-sensitive adhesive sheet is illustrated in FIG. 1. Referring to FIG. 1, a first adhesive layer 300 and a second adhesive layer 200 are formed on a barrier film including a base layer 600, a planarization layer 500, and a barrier layer 400, and the second A release film 100 is formed on the pressure-sensitive adhesive layer 200.

According to an exemplary embodiment of the present specification, an organic electronic device encapsulation product including the above-described adhesive sheet may be provided.

The organic electronic device encapsulation product includes: a substrate; An organic electronic device formed on the substrate; And a pressure-sensitive adhesive sheet encapsulating both the front surface, for example, upper and side surfaces of the organic electronic device.

The organic electronic device may be, for example, an organic light emitting device.

The organic electronic device encapsulation product may be an OLED panel.

In order to manufacture the organic electronic device, for example, it may include applying the above-described adhesive sheet to a substrate on which the organic electronic device is formed to cover the organic electronic device.

According to an exemplary embodiment of the present specification, the step of preparing a barrier film; And it can provide a pressure-sensitive adhesive sheet manufacturing method comprising the step of forming the aforementioned pressure-sensitive adhesive sheet on the barrier film.

Hereinafter, examples will be described in detail in order to describe the present specification in detail. However, the embodiments according to the present specification may be modified in various forms, and the scope of the present specification is not construed as being limited to the embodiments described below. The embodiments of the present specification are provided to more completely describe the present specification to those of ordinary skill in the art.

Manufacturing example

A pressure-sensitive adhesive composition containing 46 parts by weight of ethyl acrylate (EA), 30 parts by weight of methyl acrylate (MA), 14 parts by weight of methyl methacrylate (MMA) and 10 parts by weight of acrylic acid (AA) based on 100 parts by weight of the pressure-sensitive adhesive composition Was prepared.

Example 1

To the pressure-sensitive adhesive composition prepared as described above, acetyltributyl citrate was added as a plasticizer, and polydimethylsiloxane (BYK-377, BYK) was added to prepare a pressure-sensitive adhesive composition. The plasticizer was added in an amount of 60 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition, and polydimethylsiloxane was added in an amount of 0.05 parts by weight.

The pressure-sensitive adhesive composition was applied on a silicone release-treated polyethylene terephthalate (PET) film in 15 μm, and dried at 120° C. for 3 minutes to form a second pressure-sensitive adhesive layer.

Thereafter, an adhesive sheet was formed by laminating with the first adhesive layer (LBFL-LX, LG Chem) formed on the barrier film.

Example 2

A pressure-sensitive adhesive sheet was formed in the same manner as in Example 1, except that the content of the plasticizer was added in 55 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition to prepare the pressure-sensitive adhesive composition.

Example 3

A pressure-sensitive adhesive sheet was formed in the same manner as in Example 2, except that the content of polydimethylsiloxane was added in an amount of 0.01 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition to prepare a pressure-sensitive adhesive composition.

Example 4

A pressure-sensitive adhesive sheet was formed in the same manner as in Example 3, except that the polydimethylsiloxane was changed to OFX-04000 (Dow Corning).

Example 5

Adhesion in the same manner as in Example 1, except that the content of the plasticizer was added in an amount of 50 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition and 0.5 parts by weight of the polydimethylsiloxane based on 100 parts by weight of the pressure-sensitive adhesive composition. A sheet was formed.

Comparative Example 1

A pressure-sensitive adhesive sheet was formed in the same manner as in Example 1, except that the content of the plasticizer was added in an amount of 40 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition, and polydimethylsiloxane (BYK-377) was not added.

Comparative Example 2

A pressure-sensitive adhesive sheet was formed in the same manner as in Example 1, except that the content of the plasticizer was added in an amount of 40 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition.

Comparative Example 3

A pressure-sensitive adhesive sheet was formed in the same manner as in Example 1, except that the content of polydimethylsiloxane (BYK-377) was added in an amount of 0.7 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition.

Initial adhesion, adhesion after heat treatment, reworkability, and reliability of the pressure-sensitive adhesive sheets according to Examples and Comparative Examples were measured and described in Table 1 below.

After laminating the adhesive sheets according to the Examples and Comparative Examples on the SUS304 substrate, the initial adhesive strength was measured after leaving for 20 minutes. Thereafter, as the adhesive force after heat treatment, the adhesive force was measured after autoclaving treatment at 70° C. and 5 atm for 20 minutes.

When evaluating the reworkability, when the adhesive sheet was attached and peeled again after 5 minutes, it was marked as OK if the adhesive was removed from the substrate without remaining, and NG if the adhesive residue remained.

In addition, when evaluating the reliability, it is OK if there is no lift or bubbles at the interface between the substrate and the pressure-sensitive adhesive layer after maintaining a constant temperature and humidity chamber of 85 ℃ and 85% relative humidity for 500 hours after the autoclave treatment, and the case of occurrence is indicated as NG. I did.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Initial adhesion
(gf/in) 32 49 86 79 20 680 350 15 Adhesion after heat treatment
(gf/in) 892 998 1230 1200 630 890 560 250 responsibility OK OK OK OK OK OK OK NG Reworkability OK OK OK OK OK NG NG OK

According to Examples 1 to 5 of Table 1, it can be seen that the initial adhesive strength is low and reworkability is excellent, the adhesive strength after heat treatment is high, and the moisture permeability is low, thus satisfying reliability.

According to Comparative Examples 1 and 2 of Table 1, it can be seen that the initial adhesive strength is high, so that rework characteristics are not implemented.

According to Comparative Example 3 of Table 1, it can be seen that the reliability is not satisfied.

100: release film
200: second adhesive layer
300: first adhesive layer
400: barrier layer
500: planarization layer
600: base layer

Claims (7)

As an adhesive sheet comprising a first adhesive layer and a second adhesive layer sequentially on a barrier film,
The second pressure-sensitive adhesive layer includes at least one pressure-sensitive adhesive resin selected from olefin-based, urethane-based, acrylic-based and silicone-based, and 55 parts by weight or more of an acetyltributyl citrate (ATBC) plasticizer based on 100 parts by weight of the adhesive resin. And polydimethylsiloxane (PDMS) 0.005 parts by weight or more and 0.5 parts by weight or less,
The initial adhesive strength between the second pressure-sensitive adhesive layer and the SUS304 substrate is 15 gf/in or more and 150 gf/in or less, and the pressure-sensitive adhesive sheet having an adhesive strength of 400 gf/in or more after 20 minutes under conditions of 70°C and 5 atm. The pressure-sensitive adhesive sheet of claim 1, wherein the barrier film has a structure in which a base layer, a planarization layer, and a barrier layer are stacked. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive sheet has a water transmittance (WVTR) of 10 g/m ² ·24 h or less. The pressure-sensitive adhesive sheet according to claim 1, wherein the first pressure-sensitive adhesive layer includes a pressure-sensitive adhesive composition comprising a copolymer of diene and an olefin-based compound including one carbon-carbon double bond. The pressure-sensitive adhesive sheet according to claim 4, wherein the pressure-sensitive adhesive composition further comprises a tackifier and a curable resin. An organic electronic device encapsulation product comprising the pressure-sensitive adhesive sheet according to any one of claims 1 to 5. Preparing a barrier film; And
A method of manufacturing a pressure-sensitive adhesive sheet comprising the step of forming the pressure-sensitive adhesive sheet according to any one of claims 1 to 5 on the barrier film.

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