KR102278234B1 - Adhesive composition, adhesive film using same, backplate film comprising adhesive film and plastic organic light emitting display comprising adhesive film - Google Patents

Abstract

The present application relates to an adhesive composition, an adhesive film including the same, a backplate film including the adhesive film, and a plastic organic light emitting display including the adhesive film.

Description

A pressure-sensitive adhesive composition, a pressure-sensitive adhesive film comprising the same, a backplate film comprising the pressure-sensitive adhesive film, and a plastic organic light emitting display comprising an adhesive film TECHNICAL FIELD }

The present application relates to an adhesive composition, an adhesive film including the same, a backplate film including the adhesive film, and a plastic organic light emitting display including the adhesive film.

Conventionally, instead of a pressure-sensitive adhesive sheet having a high adhesion from the initial adhesion, a temperature-variable pressure-sensitive adhesive having a low initial adhesion and an increased adhesion later has an advantage in that it is easy to perform operations such as rework or position refresh.

In the case of conventional temperature-variable adhesives, which have low initial adhesive strength and increase adhesive strength during heat treatment at 50°C or higher, a monomer with high glass transition temperature and tens of thousands of additives in molecular weight to resin with low glass transition temperature to increase adhesive strength during heat treatment and low initial adhesive strength. was used to implement the corresponding physical properties.

However, when a resin with a low glass transition temperature is used, the initial adhesive strength is not maintained during storage at room temperature, causing a problem that the adhesive strength continuously increases, and foreign substances from the adhesive are generated during the cutting of the adhesive-coated film. can cause problems. In addition, in the case of a temperature-variable pressure-sensitive adhesive, the stability of the product over time may be deteriorated, which may cause a problem in that variable characteristics are not continuously maintained.

Therefore, in consideration of this situation, it is necessary to develop an adhesive sheet that maintains initial adhesive strength and has excellent stability over time.

Japanese Patent Laid-Open No. 2006-299283

An object of the present application is to provide a plastic organic light emitting display including an adhesive composition, an adhesive film including the same, a backplate film including the adhesive film, and an adhesive film.

An exemplary embodiment of the present application is a first polymer; and a second polymer, wherein the first polymer comprises a (meth)acrylate-based resin and a first monomer having a glass transition temperature (Tg, glass transition temperature) of 50° C. or higher, and the second polymer provides a pressure-sensitive adhesive composition comprising a second monomer having a glass transition temperature of less than 40° C. and a siloxane monomer.

Another embodiment is, the substrate layer; And it provides an adhesive film comprising a pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition or a cured product thereof according to an exemplary embodiment of the present application on one surface on the base layer.

Another exemplary embodiment, the pressure-sensitive adhesive film according to the present application; and a protective film provided on the base film side of the adhesive film.

Finally, an exemplary embodiment of the present application, the pressure-sensitive adhesive film according to the present application; a plastic substrate provided on the pressure-sensitive adhesive sheet side of the pressure-sensitive adhesive film; and an organic light emitting layer provided on a surface opposite to the surface of the plastic substrate in contact with the pressure-sensitive adhesive film.

The pressure-sensitive adhesive composition according to an exemplary embodiment of the present application includes a first monomer having a glass transition temperature of 50° C. or higher in the first polymer, and a second monomer having a glass transition temperature of less than 40° C. and a siloxane monomer. The pressure-sensitive adhesive sheet produced using the pressure-sensitive adhesive composition in the future, including the polymer, can suppress an increase in initial adhesive strength when stored at room temperature (25° C.), and has excellent rework characteristics during misadhesion.

Accordingly, the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film according to an exemplary embodiment of the present application can suppress an increase in initial adhesive strength in a storage state at room temperature, thereby preventing a phenomenon in which foreign substances of the pressure-sensitive adhesive sheet remain on the adherend substrate during cutting .

In particular, the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film according to an exemplary embodiment of the present application includes a first monomer having a high glass transition temperature in the first polymer and has excellent stability over time at room temperature (25° C.) until a variable process, It has a characteristic capable of suppressing an increase in adhesive strength.

In addition, the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film including the pressure-sensitive adhesive composition according to the exemplary embodiment of the present application has excellent variable characteristics because the adhesive strength after heat treatment is increased compared to the initial adhesive strength after the heat treatment process.

In particular, the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film according to an exemplary embodiment of the present application includes a second monomer having a low glass transition temperature in the second polymer, and thus the peel force increase after the variable process is excellent, and thus the property of having excellent variable properties. will have

1 is a view showing a schematic laminated structure of an adhesive film according to an exemplary embodiment of the present application.
2 is a view showing a schematic laminated structure of a backplate film according to an exemplary embodiment of the present application.
3 is a diagram illustrating a schematic stacked structure of a plastic organic light emitting display according to an exemplary embodiment of the present application.

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

Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

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 otherwise stated.

An exemplary embodiment of the present application is a first polymer; and a second polymer, wherein the first polymer comprises a (meth)acrylate-based resin and a first monomer having a glass transition temperature (Tg, glass transition temperature) of 50° C. or higher, and the second polymer provides a pressure-sensitive adhesive composition comprising a second monomer having a glass transition temperature of less than 40° C. and a siloxane monomer.

In the present specification, the glass transition temperature is determined by using a differential scanning calorimeter (DSC, Mettler) to seal a sample of about 10 mg in a dedicated pan and heat it to a constant temperature environment. It is a measured value by plotting endothermic and calorific values according to temperature.

Specifically, the glass transition temperature is a nominal value described in literature, catalogs, etc., or a value calculated based on the following general formula (1) (Fox formula).

[General formula (1)]

1/Tg=W1/Tg1+W2/Tg2+ … +Wn/Tgn

In the general formula (1), Tg is the glass transition temperature of the polymer A (unit: K), Tgi (i = 1, 2, ... n) is the glass transition temperature when the monomer i forms a homopolymer (unit: K) : K) and Wi (i = 1, 2, ... n) represent the mass fraction of the monomer i in all the monomer components.

The general formula (1) is that polymer A is monomer 1, monomer 2, ... , means a calculation formula in the case of including n types of monomer components of the monomer n.

In the present application, that the first polymer and the second polymer include a monomer may mean a state in which a bond between the monomer and the monomer is formed.

In the present application, the glass transition temperature of the first monomer and the second monomer means the glass transition temperature value of the polymer when each monomer forms a single polymer, and can be measured as described above.

The pressure-sensitive adhesive composition according to an exemplary embodiment of the present application includes a first polymer and a second polymer, and the first polymer includes the (meth)acrylate-based resin and a first monomer having a glass transition temperature value of 50° C. or higher Accordingly, it is possible to provide an adhesive sheet capable of suppressing an increase in initial adhesive strength when stored at room temperature (25° C.) later.

Accordingly, the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film according to an exemplary embodiment of the present application can suppress an increase in initial adhesive strength in a storage state at room temperature, thereby preventing foreign substances of the pressure-sensitive adhesive sheet from remaining on the base layer during cutting .

In addition, the pressure-sensitive adhesive composition according to an exemplary embodiment of the present application includes a first polymer and a second polymer, and the second polymer includes a second monomer and a siloxane monomer having the glass transition temperature value of less than 40° C., at room temperature ( 25 ℃) storage stability over time, and after the heat treatment process, the adhesive strength after heat treatment is increased compared to the initial adhesive strength, so it has excellent variable characteristics.

The excellent variable properties mean that the difference between the initial adhesive strength and the late adhesive strength after a specific heat treatment process is large, and the change characteristics of the initial and late adhesive strength are particularly excellent, and further between the second polymers after the heat treatment process Since it has a stable arrangement, it has particularly excellent adhesion properties.

In an exemplary embodiment of the present application, the (meth)acrylate-based resin may include a (meth)acrylate-based resin having a weight average molecular weight of 400,000 g/mol to 2 million g/mol.

The weight average molecular weight is one of the average molecular weights for which the molecular weight is not uniform and the molecular weight of a certain polymer material is used as a reference, and is a value obtained by averaging the molecular weights of component molecular species of a polymer compound having a molecular weight distribution by weight fraction.

The weight average molecular weight may be measured through Gel Permeation Chromatography (GPC) analysis.

In the present specification, (meth) acrylate is meant to include both acrylate and methacrylate. The (meth)acrylate-based resin may be, for example, a copolymer of a (meth)acrylic acid ester-based monomer and a crosslinkable functional group-containing monomer.

The (meth)acrylic acid ester-based monomer is not particularly limited, but for example, an alkyl (meth)acrylate, and more specifically, a monomer having an alkyl group having 1 to 12 carbon atoms, pentyl (meth)acrylate, n-butyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethyl One or two or more of hexyl (meth)acrylate, dodecyl (meth)acrylate, and decyl (meth)acrylate may be included.

The crosslinkable functional group-containing monomer is not particularly limited, but may include, for example, one or two or more of a hydroxyl group-containing monomer, a carboxyl group-containing monomer, and a nitrogen-containing monomer.

Examples of the hydroxyl group-containing compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate ) acrylate, 8-hydroxyoctyl (meth)acrylate, 2-hydroxyethylene glycol (meth)acrylate, or 2-hydroxypropylene glycol (meth)acrylate.

Examples of the carboxyl group-containing compound include (meth)acrylic acid, 2-(meth)acryloyloxyacetic acid, 3-(meth)acryloyloxypropyl acid, 4-(meth)acryloyloxybutyric acid, acrylic acid double Sieve, itaconic acid, maleic acid, or maleic anhydride, etc. are mentioned.

Examples of the nitrogen-containing monomer include (meth)acrylonitrile, N-vinyl pyrrolidone or N-vinyl caprolactam.

At least one of vinyl acetate, styrene, and acrylonitrile may be further copolymerized with the (meth)acrylate-based resin from the viewpoint of improving other functionalities such as compatibility.

In an exemplary embodiment of the present application, the acrylate-based resin may have a glass transition temperature of less than 50° C., preferably less than 40° C., and may be -150° C. or higher.

In an exemplary embodiment of the present application, the first monomer may have a glass transition temperature of 50°C or higher, preferably 55°C or higher, and more preferably 60°C or higher.

In another exemplary embodiment, the first monomer may have a glass transition temperature of 150° C. or less, preferably 130° C. or less.

Examples of the first monomer include methyl methacrylate (MMA, methyl methacrylate), vinylpyrrolidone (VP, N-Vinylpyrrolidone), isobornyl acrylate, and isobornyl methacrylate (isobornyl). It may be selected from the group consisting of methacrylate), but is not limited thereto.

As the first monomer satisfies the glass transition temperature, it is possible to suppress an increase in the adhesive strength of the pressure-sensitive adhesive sheet at room temperature later, and to maintain the peeling force in a low state.

In an exemplary embodiment of the present application, the content of the first monomer having a glass transition temperature value of 50° C. or higher is 5 parts by weight or more and 40 parts by weight or less based on 100 parts by weight of the first polymer.

In another exemplary embodiment, the content of the first monomer having a glass transition temperature value of 50° C. or higher is 7 parts by weight or more and 35 parts by weight or less, preferably 10 parts by weight or more and 35 parts by weight based on 100 parts by weight of the first polymer. may be less than or equal to

By including the first monomer having the glass transition temperature range and the content in the first polymer, it is possible to form a pressure-sensitive adhesive sheet having a low initial adhesive strength, and also to suppress an increase in the initial room temperature adhesive strength during storage at room temperature Therefore, even if stored for a long time at room temperature, there is a characteristic that foreign substances of the adhesive sheet do not remain when the film is cut later.

In an exemplary embodiment of the present application, the weight average molecular weight of the second polymer including the second monomer and the siloxane monomer having the glass transition temperature value of less than 40° C. may be 50,000 g/mol or more and 200,000 g/mol or less.

The weight average molecular weight of the second polymer means the weight average molecular weight of the entire second polymer in which the glass transition temperature value is less than 40° C. and the second monomer and the siloxane monomer are polymerized.

In another exemplary embodiment, the weight average molecular weight of the second polymer comprising the second monomer and the siloxane monomer having a glass transition temperature of less than 40° C. is 50,000 g/mol or more and 150,000 g/mol or less, preferably It may be 50,000 g/mol or more and 130,000 g/mol or less.

When the second polymer has a weight average molecular weight within the above range, the stability over room temperature of the pressure-sensitive adhesive sheet included in the pressure-sensitive adhesive film may be particularly excellent, and variable properties may be maintained for a long time, and adhesive strength may also be excellent in the future.

In an exemplary embodiment of the present application, the second monomer may have a glass transition temperature of less than 40°C, preferably less than 35°C.

In another exemplary embodiment, the second monomer may have a glass transition temperature of -20°C or higher.

In an exemplary embodiment of the present application, the second monomer may be selected from the group consisting of butyl methacrylate (BMA, Butylmethacrylate) and ethylhexyl methacrylate (EHMA, Ethyl hexyl methacrylate), but is limited thereto no.

In an exemplary embodiment of the present application, the content of the second monomer having the glass transition temperature value of less than 40° C. may be 10 parts by weight or more and 80 parts by weight or less based on 100 parts by weight of the second polymer.

In another exemplary embodiment, the content of the second monomer having a glass transition temperature value of less than 40° C. is 20 parts by weight or more and 70 parts by weight or less, preferably 30 parts by weight or more and 60 parts by weight based on 100 parts by weight of the second polymer. may be less than or equal to

By including the second monomer having the glass transition temperature range and the content in the second polymer, when the pressure-sensitive adhesive film including the same is subsequently heat treated, the adhesive strength increase rate is increased compared to the initial adhesive strength, and thus has excellent variable properties. This is because, in the case of the second monomer satisfying the glass transition temperature, mobility is particularly excellent at a variable process temperature.

In the exemplary embodiment of the present application, the siloxane monomer means a monomer containing silicon (Si) in the monomer.

In an exemplary embodiment of the present application, the second polymer provides an amount of 0.01 parts by weight or more and 10 parts by weight or less based on 100 parts by weight of the first polymer.

In another exemplary embodiment, the amount of the second polymer may be 0.1 to 8 parts by weight, preferably 1 to 7 parts by weight, based on 100 parts by weight of the first polymer.

When the second polymer has the above range with respect to the first polymer, the second polymer can stably and sufficiently cover the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet, so that the adhesive force before the heat treatment process can be maintained low. .

In an exemplary embodiment of the present application, the pressure-sensitive adhesive composition further comprises one or more selected from the group consisting of a solvent, a dispersant, a cross-linkable compound, a photoinitiator, a thermal initiator, a tackifier, and a silane coupling agent. provides

In particular, the silane coupling agent may be used for the reliability of heat-and-moisture resistance of the adhesive sheet.

According to an exemplary embodiment of the present specification, the cross-linkable compound is hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups, trimethyl Allpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, 2-trisacryloyloxymethylethylphthalic acid, propylene group Acidic modifications of propylene glycol di(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate with the number of a compound obtained by esterifying a polyhydric alcohol such as a mixture of pentaerythritol hexa(meth)acrylate (trade name: TO-2348, TO-2349, manufactured by Dong-A Synthetic Co., Ltd., Japan) with α,β-unsaturated carboxylic acid; a compound obtained by adding (meth)acrylic acid to a compound containing a glycidyl group, such as a trimethylolpropane triglycidyl ether acrylic acid adduct and a bisphenol A diglycidyl ether acrylic acid adduct; Ester compound of a compound having a hydroxyl group or an ethylenically unsaturated bond, such as a phthalic acid diester of β-hydroxyethyl (meth)acrylate and a toluene diisocyanate adduct of β-hydroxyethyl (meth)acrylate, and a polyhydric carboxylic acid , or adducts with polyisocyanates; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; and 9,9'-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, which may include one or more selected from the group consisting of, but not limited to, those known in the art. You can use common ones.

According to an exemplary embodiment of the present specification, the photoinitiator is a triazine-based compound, a biimidazole compound, an acetophenone-based compound, an O-acyloxime-based compound, a thioxanthone-based compound, a phosphine oxide-based compound, a coumarin-based compound, and a benzophenone It may be substituted with one or two or more substituents selected from the group consisting of non-based compounds.

Specifically, according to an exemplary embodiment of the present specification, the photoinitiator is 2,4-trichloromethyl-(4'-methoxyphenyl)-6-triazine, 2,4-trichloromethyl-(4'-methyl Toxystyryl)-6-triazine, 2,4-trichloromethyl-(piflonyl)-6-triazine, 2,4-trichloromethyl-(3',4'-dimethoxyphenyl)-6 -triazine, 3-{4-[2,4-bis(trichloromethyl)-s-triazin-6-yl]phenylthio}propanoic acid, 2,4-trichloromethyl-(4'-ethyl ratio triazine-based compounds such as phenyl)-6-triazine or 2,4-trichloromethyl-(4'-methylbiphenyl)-6-triazine; 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl biimidazole or 2,2'-bis(2,3-dichlorophenyl)-4,4',5 biimidazole-based compounds such as ,5'-tetraphenylbiimidazole; 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxye Toxy)-phenyl (2-hydroxy)propyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenyl acetophenone, 2-methyl-(4-methylthiophenyl)-2-mol Acetopes such as polyno-1-propan-1-one (Irgacure-907) or 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one (Irgacure-369) non-type compounds; O-acyloxime compounds such as Irgacure OXE 01 and Irgacure OXE 02 manufactured by Ciba Geigy; benzophenone compounds such as 4,4'-bis(dimethylamino)benzophenone or 4,4'-bis(diethylamino)benzophenone; thioxanthone-based compounds such as 2,4-diethyl thioxanthone, 2-chlorothioxanthone, isopropyl thioxanthone or diisopropyl thioxanthone; 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphine oxide or bis(2,6-dichlorobenzoyl)propyl phosphine oxide Phosphine oxide type compounds, such as; 3,3'-carbonylvinyl-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-benzoyl-7-(diethylamino)coumarin; 3-benzoyl-7-methoxy-coumarin or 10,10'-carbonylbis[1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-Cl] Coumarin-based compounds such as -benzopyrano[6,7,8-ij]-quinolizin-11-one may be used alone or two or more may be mixed, but the present invention is not limited thereto.

In addition, the thermal initiator may use one known in the art.

As the solvent, a commonly used organic solvent may be used, and a polar aprotic solvent may be used, and specifically, methylethly ketone, toluene, or ethyl acetate solvent may be used.

In an exemplary embodiment of the present application, the substrate layer; And it provides an adhesive film comprising a pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition or a cured product thereof on one surface on the base layer.

In the exemplary embodiment of the present application, the base layer is PET (polyethylene terephthalate), polyester, PC (polycarbonate), PI (polyimide), PEN (polyethylene naphthalate), PEEK (polyether ether ketone), PAR ( polyarylate), polycylicolefin (PCO), polynorbornene, polyethersulphone (PES), and cycloolefin polymer (COP).

In another exemplary embodiment, the base film may be polyethylene terephthalate (PET).

The laminated structure of the adhesive film can be seen in FIG. 1 , and specifically, it has a structure in which the base layer 101 and the adhesive sheet 102 are sequentially laminated.

In an exemplary embodiment of the present application, the pressure-sensitive adhesive sheet may include the pressure-sensitive adhesive composition according to the exemplary embodiment of the present application as it is.

In an exemplary embodiment of the present application, the pressure-sensitive adhesive sheet may include a cured product of the pressure-sensitive adhesive composition according to the exemplary embodiment of the present application.

In an exemplary embodiment of the application, there is provided an adhesive film further comprising a release film on the opposite surface of the surface in contact with the base layer of the adhesive sheet.

As the release film, a hydrophobic film may be used, and as a layer for protecting a very thin pressure-sensitive adhesive sheet, it refers to a transparent layer attached to one surface of the pressure-sensitive adhesive sheet, and a film excellent in mechanical strength, thermal stability, moisture shielding property, isotropy, etc. can be used For example, acetate-based, polyester-based, polyethersulfone-based, polycarbonate-based, polyamide-based, polyimide-based, polyolefin-based, cycloolefin-based, polyurethane-based and acrylic resin films such as triacetyl cellulose (TAC) can be used, but is not limited thereto if it is a commercially available silicone-treated release film.

In an exemplary embodiment of the present application, the thickness of the base layer is 10 μm or more and 150 μm or less, preferably 15 µm or more and 150 µm or less, and more preferably 20 µm or more and 150 µm or less.

In addition, the substrate layer is preferably transparent. The meaning that the base layer is transparent here means that the light transmittance of visible light (400-700 nm) is 80% or more.

When the base layer has the above range, the laminated pressure-sensitive adhesive film has a property capable of being thinned.

In an exemplary embodiment of the present application, the thickness of the pressure-sensitive adhesive sheet is 1 μm or more and 50 μm may be below.

In another exemplary embodiment, the thickness of the pressure-sensitive adhesive sheet is 3 μm or more and 50 μm or less, preferably 5 µm or more and 50 µm or less, more preferably 10 µm or more and 45 µm may be below.

When the thickness of the pressure-sensitive adhesive sheet is within the above range, the rework property is excellent during mis-attachment, and in particular, when the pressure-sensitive adhesive sheet is removed, foreign substances are not left.

In an exemplary embodiment of the present application, the thickness of the adhesive film is 11 μm or more and 200 μm It provides the following adhesive films.

In another exemplary embodiment, the thickness of the adhesive film is 15 μm or more and 190 μm or less, preferably 15 µm or more and 180 µm or less, more preferably 20 µm or more and 180 µm may be below.

Since the pressure-sensitive adhesive film has the above range, the thickness as a back plate is suitable when applied to a plastic organic light emitting display in the future, and the rework property is excellent when mis-attached, and in particular, when removing the pressure-sensitive adhesive sheet, foreign substances are It has a characteristic that does not remain.

In an exemplary embodiment of the present application, the initial adhesive strength after bonding the opposite side of the side in contact with the base layer of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate) and leaving it at 23° C. for 2 hours is 100 gf/inch or less, and the After heat treatment at 60° C. and leaving for 20 minutes, the late adhesive strength may be 500 gf/inch or more.

The initial adhesive force means the adhesive force after bonding the opposite side of the surface in contact with the base layer of the adhesive sheet to stainless steel (SUS304 substrate) and leaving it at 23° C. for 2 hours, and the late adhesive strength is the adhesive strength of the adhesive sheet. After bonding the opposite surface of the surface in contact with the base layer to stainless steel (SUS304 substrate), it means the adhesive force after storage at 23° C. for 2 hours, heat treatment at 60° C. and leaving it for 20 minutes.

The initial adhesive strength and the late adhesive strength are measured by reciprocating the adhesive sheet prepared by the present invention once with a 2 kg rubber roller and attaching it to a stainless steel (SUS304 mirror substrate), followed by a texture annealer at a 180° angle and a peeling rate of 1800 mm/min. (Texture analyzer (Stable Micro Systems) was used for measurement.

In another exemplary embodiment, the initial adhesive strength after bonding the opposite side of the surface in contact with the base layer of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate) and leaving it at 23° C. for 2 hours is 100 gf/inch or less, preferably 95 gf/inch or less, more preferably 85 gf/inch or less.

In another embodiment, the initial adhesive strength after bonding the opposite side of the surface in contact with the base layer of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate) and leaving it at 23° C. for 2 hours is 5 gf/inch or more, preferably It may be 10 gf/inch or more, more preferably 15 gf/inch or more.

In an exemplary embodiment of the present application, the late adhesive strength may be 500 gf/inch or more, preferably 600 gf/inch or more, and more preferably 650 gf/inch or more.

In another exemplary embodiment, the late adhesive force may be 3000 gf/inch or less, preferably 2800 gf/inch or less, and more preferably 2500 gf/inch or less.

In another exemplary embodiment, the late adhesive force may be 500 gf / inch or more and 3000 gf / inch or less.

In another exemplary embodiment, the late adhesive force may be 500 gf/inch or more and 2000 gf/inch or less.

In another exemplary embodiment, the late adhesive force may be 500 gf/inch or more and 1000 gf/inch or less.

In an exemplary embodiment of the present application, the late adhesive force/the initial adhesive force satisfies a value of 5 or more and 100 or less.

It can be confirmed that the pressure-sensitive adhesive sheet according to the present application has very excellent variable properties with the value of the late adhesive force/the initial adhesive force.

In an exemplary embodiment of the present application, the pressure-sensitive adhesive sheet and the base layer may be laminated in plurality.

In the present application, the pressure-sensitive adhesive film may be prepared by applying the pressure-sensitive adhesive composition on the base layer with a bar coater.

An exemplary embodiment of the present application is an adhesive film according to the present application; and a protective film provided on the substrate layer side of the adhesive film.

An exemplary embodiment of the present application is an adhesive film according to the present application; and a protective film provided on one side of the pressure-sensitive adhesive film, wherein the pressure-sensitive adhesive film includes a base layer and an adhesive sheet, and a protective film is provided on the opposite side of the surface of the base layer in contact with the pressure-sensitive adhesive sheet. An object of the present invention is to provide a back plate film.

The laminated structure of the backplate film can be seen in FIG. 2 . Specifically, it has a laminated structure of an adhesive film 103 and a protective film 104 , and more specifically, the adhesive sheet 103 is composed of a base layer 101 and an adhesive sheet 102 , and It can be seen that one side of the backplate film 105 is bonded to the protective film 104 .

In the film for back play, the protective film serves to protect the adhesive film during transport or process of the back plate film. When the back plate film is later used in a plastic organic light emitting display, the protective film may be removed. can

In an exemplary embodiment of the present application, the protective film may include a protective substrate; and an adhesive layer.

The protective substrate may be the same as that of the substrate layer.

The adhesive layer is not limited thereto, as long as it can adhere the protective substrate and the substrate layer, and a commercially available general adhesive layer may be used.

An exemplary embodiment of the present application is an adhesive film according to the present application; a plastic substrate provided on the pressure-sensitive adhesive sheet side of the pressure-sensitive adhesive film; and an organic light emitting layer provided on a surface opposite to the surface of the plastic substrate in contact with the pressure-sensitive adhesive film.

An exemplary embodiment of the present application is an adhesive film according to the present application; a plastic substrate provided on one surface of the adhesive film; and an organic light emitting layer provided on a surface opposite to the surface in contact with the pressure-sensitive adhesive film of the plastic substrate, wherein the pressure-sensitive adhesive film includes a base layer and an pressure-sensitive adhesive sheet, and the base layer of the pressure-sensitive adhesive sheet An object of the present invention is to provide a plastic organic light emitting display in which a plastic substrate is provided on a surface opposite to the contact surface.

In an exemplary embodiment of the present application, there is provided a plastic organic light emitting display comprising a protective film provided on the side of the base layer of the adhesive film.

The laminated structure of the plastic organic light emitting display can be seen in FIG. 3 . Specifically, the protective film 104; adhesive film 103; plastic substrate 106; and a laminated structure of the organic light emitting layer 107 , and more specifically, the laminated structure of the plastic organic light emitting display in which the adhesive sheet 102 of the adhesive film 103 and the plastic substrate 106 are bonded.

The protective film may be removed from the laminated structure of the plastic organic light emitting display.

As the plastic substrate, polyimide (PI) may be used.

The organic light emitting layer may be selected from the group consisting of an organic photoelectric device, an organic transistor, an organic solar cell, an organic light emitting device, and a micro LED device.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

< manufacturing example >

Components and weight ratios of the pressure-sensitive adhesive compositions used in Examples and Comparative Examples of the present application are described in Table 1 below.

first polymer second polymer Furtherance
(weight ratio) parts by weight Example 1 EHA/MMA/HEA
(65/20/15) FM0721:BMA
=2:8 5 Example 2 EHA/MMA/VP/HEA (65/20/10/5) FM0721: EHMA/MMA
=2:4:4 5 Example 3 EHA/MMA/VP/HEA (65/20/10/5) FM0721:EHMA/BMA/MMA
=2:2:2:4 5 Comparative Example 1 EHA/HEA (75/15) FM0721: EHMA/MMA
=2:4:4 5 Comparative Example 2 EHA/MMA/VP/HEA (65/15/5/15) FM0721:MMA
=2:8 5

In Table 1, EHA means ethylhexylacrylate, MMA means methylmethacrylate, VP means vinylpyrrolidone (N-Vinylpyrrolidone), and BMA means butyl methacrylate ( Butylmethacrylate) and EHMA means ethyl hexyl methacrylate, respectively.

In Table 1, parts by weight of the second polymer are shown based on 100 parts by weight of the first polymer.

As the monofunctional polysiloxane in Table 1, FM-0721 manufactured by Chisso was used.

With respect to the pressure-sensitive adhesive composition having the composition and weight ratio of Table 1, after lamy the pressure-sensitive adhesive composition prepared in Table 1 on the SUS304 substrate, the adhesive force values measured under the following conditions are shown in Table 2 below.

adhesiveness initial adhesion
(gf/in) Late Adhesion
(gf/in) Example 1 81 642 Example 2 61 728 Example 3 73 651 Comparative Example 1 210 760 Comparative Example 2 32 54

1. Initial Adhesion: One of the films prepared in Examples 1 to 3 and Comparative Examples 1 and 2 was laminated on a SUS304 substrate by reciprocating it once with a 2 kg rubber roller, and then left at 23° C. for 2 hours. The film on the SUS304 substrate was measured using a texture analyzer (Texture Analyzer (Stable Micro Systems)) at an angle of 180° and a peeling rate of 300 mm/min.

2. Late adhesive strength: One adhesive sheet of the films prepared in Examples 1 to 3 and Comparative Examples 1 and 2 was laminated on a SUS304 substrate by reciprocating once with a 2 kg rubber roller, and then heat treatment process at 60° C. and 20 minutes After standing, the film from the SUS304 substrate was measured using a texture analyzer (Stable Micro Systems) at an angle of 180° and a peeling rate of 300 mm/min.

As can be seen from Table 2, in the case of the pressure-sensitive adhesive sheet including the pressure-sensitive adhesive composition (Examples 1 to 3) according to an exemplary embodiment of the present application, it was confirmed that the initial adhesive force was maintained low. In addition, as can be seen from Table 2, it was confirmed that the late adhesive strength was significantly increased compared to the initial adhesive strength.

This means that the variable characteristics are very good, and when applied to a foldable display, a process of partially removing the adhesive sheet is required, and accordingly, it is necessary to have low initial adhesive strength and low initial adhesive strength for leaving, and adhesion after the removal process Since the adhesive force with the substrate should be increased, it was confirmed that the adhesive film according to the present application was excellent for application to a foldable display.

In addition, in the case of the pressure-sensitive adhesive film according to the present application, it can be confirmed that the initial adhesive strength is maintained low without increasing, which means that the stability over time is excellent.

Specifically, in Examples 1 to 3, including the first monomer having a high glass transition temperature in the first polymer, the adhesion at room temperature is formed low until the variable process, and the stability over time is excellent, so that the increase in adhesion can be suppressed have characteristics. In addition, the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film according to an exemplary embodiment of the present application includes a second monomer having a low glass transition temperature in the second polymer, and thus the peel force increase after the variable process is excellent, and thus the property of having excellent variable properties. will have

On the other hand, in the case of Comparative Example 1, although some of the variable properties are implemented, the degree is insignificant, and in particular, the first polymer does not contain a first monomer having a high glass transition temperature, so that the initial adhesive strength is very increased. can be checked It was confirmed that such a pressure-sensitive adhesive sheet is not suitable because a residue is left on the substrate to be adhered during the partial removal process of the pressure-sensitive adhesive sheet.

In addition, in the case of Comparative Example 2, although the initial adhesive force is maintained low, it can be confirmed that the variable characteristics are not implemented. This is because the second polymer does not contain a second monomer with a low glass transition temperature value, so variable properties are not implemented, which is advantageous for some removal processes of the pressure-sensitive adhesive sheet, but is not suitable because adhesive strength with the substrate to be adhered is not maintained thereafter. was able to confirm

101: substrate layer
102: adhesive sheet
103: adhesive film
104: protective film
105: back plate film
106: plastic substrate
107: organic light emitting layer

Claims (16)

a first polymer; and
A pressure-sensitive adhesive composition comprising a second polymer,
The first polymer includes a (meth)acrylate-based resin and a first monomer having a glass transition temperature value (Tg, glass transition temperature) of 50° C. or higher,
wherein the second polymer comprises a second monomer having a glass transition temperature value of less than 40° C. and a siloxane monomer;
The pressure-sensitive adhesive composition of the second polymer is included in an amount of 0.1 parts by weight or more and 10 parts by weight or less based on 100 parts by weight of the first polymer. The pressure-sensitive adhesive composition according to claim 1, wherein the weight average molecular weight of the second polymer including the second monomer and the siloxane monomer having a glass transition temperature value of less than 40°C is 50,000 g/mol or more and 200,000 g/mol or less. The pressure-sensitive adhesive composition according to claim 1, wherein the content of the first monomer having a glass transition temperature value of 50°C or higher is 5 parts by weight or more and 40 parts by weight or less based on 100 parts by weight of the first polymer. delete The pressure-sensitive adhesive composition according to claim 1, wherein the content of the second monomer having a glass transition temperature of less than 40° C. is 20 parts by weight or more and 80 parts by weight or less based on 100 parts by weight of the second polymer. The method according to claim 1,
The first monomer is methyl methacrylate (MMA, methyl methacrylate), vinylpyrrolidone (VP, N-Vinylpyrrolidone), isoboronyl acrylate (isobornyl acrylate) and isobornyl methacrylate A pressure-sensitive adhesive composition selected from the group consisting of. The method according to claim 1,
The second monomer is a pressure-sensitive adhesive composition selected from the group consisting of butyl methacrylate (BMA, Butylmethacrylate) and ethylhexyl methacrylate (EHMA, Ethyl hexyl methacrylate). The pressure-sensitive adhesive composition according to claim 1, further comprising at least one selected from the group consisting of a solvent, a dispersant, a crosslinking compound, a photoinitiator, a thermal initiator, a tackifier, and a silane coupling agent. substrate layer; and
A pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition of any one of claims 1 to 3 and 5 to 8 or a cured product thereof on one surface on the base layer;
An adhesive film comprising a. 10. The method of claim 9,
The base layer is PET (polyethylene terephthalate), polyester, PC (polycarbonate), PI (polyimide), PEN (polyethylene naphthalate), PEEK (polyether ether ketone), PAR (polyarylate), PCO (polycylicolefin), poly An adhesive film comprising at least one selected from the group consisting of norbornene, polyethersulphone (PES), and cycloolefin polymer (COP). The adhesive film of claim 9, wherein the pressure-sensitive adhesive sheet has a thickness of 1 μm or more and 50 μm or less. The adhesive film according to claim 9, wherein the thickness of the base layer is 10 μm or more and 150 μm or less. The method according to claim 9, After bonding the opposite surface of the surface in contact with the base layer of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after leaving at 23 ° C. for 2 hours is 100 gf/inch or less, and then at 60 ° C. An adhesive film having a late adhesive strength of 500 gf/inch or more after heat treatment and leaving for 20 minutes. The adhesive film according to claim 9; and
a protective film provided on the substrate layer side of the adhesive film;
A back plate film comprising a. The adhesive film according to claim 9;
a plastic substrate provided on the pressure-sensitive adhesive sheet side of the pressure-sensitive adhesive film; and
an organic light emitting layer provided on a surface opposite to the surface of the plastic substrate in contact with the pressure-sensitive adhesive film;
A plastic organic light emitting display comprising a. 16. The method of claim 15,
A plastic organic light emitting display comprising a protective film provided on the side of the base layer of the adhesive film.

Images