KR102452804B1 - Adhesive composition, adhesive film comprising same, manufacturing method of adhesive film and plastic organic light emitting display comprising same - Google Patents

Abstract

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

Description

A pressure-sensitive adhesive composition, an adhesive film comprising the same, a method for manufacturing an adhesive film, and a plastic organic light emitting display comprising the same

The present application relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film including the same, a method for manufacturing the pressure-sensitive adhesive film, and a plastic organic light emitting display including the same.

Recently, with the development of display-related technologies, display devices that can be deformed in the use stage, such as folding, rolling in a roll shape, or stretching like a rubber band, are being researched and developed. Since these displays can be deformed into various shapes, it is possible to satisfy both the demand for enlargement of the display in the use stage and the demand for miniaturization of the display for portability.

DESCRIPTION OF RELATED ART Conventionally, the adhesive sheet which has high adhesive force from an adhesion initial stage is known. In addition, when fixing the base material using such an adhesive sheet, an adhesive sheet having sufficient adhesive force to fix the base material is selected.

On the other hand, bubbles or unexpected foreign substances generated in the process of bonding the pressure-sensitive adhesive sheet to the substrate may be introduced, which is not preferable from the viewpoint of aesthetics or adhesiveness, and may require re-adhesion of the pressure-sensitive adhesive sheet. However, in the case of an adhesive sheet with high adhesive strength, such a re-adhesive operation is difficult.

Then, the technique of reducing such a bubble is devised. For example, there has been devised a technique for forming an uneven surface shape on an adhesive surface of a pressure-sensitive adhesive by using an embossed liner. In this case, even if air bubbles are mixed between the pressure-sensitive adhesives when the pressure-sensitive adhesive is bonded to the substrate, air easily flows out through the surface grooves of the pressure-sensitive adhesive, so that the air bubbles are easily removed without re-adhesiveness. However, the pressure-sensitive adhesive described above requires a certain thickness to form the grooves. In addition, when this pressure-sensitive adhesive is lightly adhered to the base material, the adhesive area becomes small due to the presence of grooves, which makes it easier to perform operations such as rework and position refresh, but sufficient adhesive force cannot be obtained. There is a possibility.

In order to strengthen the rework characteristics, recently, adhesive sheets are being developed in which the adhesive strength is kept low in the initial stage of the adhesive sheet, and the adhesive strength is increased after a specific process.

Therefore, in consideration of this situation, it is necessary to develop an adhesive sheet that can be used for a deformable display and can efficiently remove foreign substances and air bubbles between the adhesive sheet and the substrate while expressing the adhesive force required for fixing. do.

Japanese Patent Laid-Open No. 2006-299283

An object of the present application is to provide a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film including the same, a method for manufacturing the pressure-sensitive adhesive film, and a plastic organic light emitting display including the same.

An exemplary embodiment of the present application is a (meth) acrylate-based first polymer; a second polymer comprising at least one unit derived from a monomer represented by the following formula (1), and including a unit derived from a monomer represented by the following formula (2) or formula (3); And to provide a pressure-sensitive adhesive composition comprising a crosslinking agent.

[Formula 1]

[Formula 2]

[Formula 3]

In Formulas 1 to 3,

R ₁ is hydrogen; or a methyl group,

R ₂ is hydrogen; or an alkyl group,

R ₃ is a monofunctional acrylate,

m is an integer from 0 to 200,

n is an integer from 5 to 30;

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

Another embodiment is to prepare a base film; and applying and curing the pressure-sensitive adhesive composition according to the present application on one surface of the base film to form a pressure-sensitive adhesive sheet,

After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after standing at 23° C. for 2 hours is 100 gf/inch or less, and then after heat treatment at 50° C. for 20 minutes An object of the present invention is to provide a method for manufacturing an adhesive film having an adhesive strength of 300 gf/inch or more.

Finally, an exemplary embodiment of the present application is an adhesive film according to the present application; a plastic substrate provided on the adhesive sheet side of the 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 (meth)acrylate-based first polymer; and a second polymer comprising at least one unit derived from a monomer represented by Formula 1 and a unit derived from a monomer represented by Formula 2 or Formula 3 to form an adhesive sheet, When the pressure-sensitive adhesive sheet is initially adhered to the substrate, it is possible to provide a reworkable pressure-sensitive adhesive sheet having a low initial adhesive strength during erroneous attachment such as generation of bubbles and foreign substances.

In addition, the pressure-sensitive adhesive sheet may provide a pressure-sensitive adhesive sheet having excellent variable performance in which adhesive strength with a substrate increases after a specific process.

In particular, in the pressure-sensitive adhesive composition, when the n value of the monomer represented by Formula 1 has a value of 5 or more, it is possible to provide an adhesive sheet having particularly excellent variable performance.

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 diagram illustrating a laminated structure of an adhesive film including a release film according to an exemplary embodiment of the present application.

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

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.

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 several different forms and is not limited to the embodiments described herein.

An exemplary embodiment of the present application is a (meth) acrylate-based first polymer; a second polymer comprising at least one unit derived from a monomer represented by the following formula (1), and including a unit derived from a monomer represented by the following formula (2) or formula (3); And to provide a pressure-sensitive adhesive composition comprising a crosslinking agent.

[Formula 1]

[Formula 2]

[Formula 3]

In Formulas 1 to 3,

R ₁ is hydrogen; or a methyl group,

R ₂ is hydrogen; or an alkyl group,

R ₃ is a monofunctional acrylate,

m is an integer from 0 to 200,

n is an integer from 5 to 30;

In the exemplary embodiment of the present application, R ₁ may be hydrogen.

In the exemplary embodiment of the present application, R ₁ may be a methyl group.

In an exemplary embodiment of the present application, R ₂ Is hydrogen; Or it may be an alkyl group having 1 to 30 carbon atoms.

In an exemplary embodiment of the present application, R ₃ is a functional group having a (meth)acryl group, and the functional group having a (meth)acrylic group may mean a (meth)acryl group itself, and also a functional group (meth) It means that it has an acrylic group and may further include other organic groups.

In the exemplary embodiment of the present application, R ₃ may be represented by the following formula (4).

[Formula 4]

In Formula 4,

R ₄ is hydrogen or an alkyl group,

x is an integer greater than or equal to 0.

In an exemplary embodiment of the present application, R ₄ Is hydrogen; Or it may be an alkyl group having 1 to 30 carbon atoms.

In another exemplary embodiment, R ₄ Is hydrogen; Or it may be an alkyl group having 1 to 10 carbon atoms.

In another exemplary embodiment, R ₄ Is hydrogen; or a methyl group.

In an exemplary embodiment of the present application, x may be an integer of 0 or more, preferably an integer of 0 or more and 100 or less, and more preferably an integer of 0 or more and 50 or less.

In the exemplary embodiment of the present application, m may be an integer of 0 to 200.

In another exemplary embodiment, m may be an integer of 0 or more and 200 or less, preferably an integer of 0 or more and 190 or less, and more preferably an integer of 0 or more and 150 or less.

In an exemplary embodiment of the present application, n may be an integer of 5 to 30.

In another exemplary embodiment, n may be an integer of 5 to 30, preferably an integer of 5 to 28, more preferably an integer of 5 to 25.

When n has the above range, the alkyl part of the unit derived from the monomer represented by Formula 1 has a long chain alkyl group structure, and in this case, a short chain alkyl group having a small number of carbon atoms It has particularly excellent characteristics of changing the initial and late adhesion strength than the monomers having it, and has a more stable arrangement between the monomers after the heat treatment process, so that the late adhesion characteristics are particularly excellent.

In addition, when the alkyl moiety of the unit derived from the monomer represented by Formula 1 has a cyclic form, the arrangement of the monomers is not constant compared to the case of the present invention having a chain form, so that the adhesive properties are not good. will have

In particular, in the case of the unit derived from the monomer represented by the formula (1), as the chain of the alkyl moiety has a specific n value or more range, the adhesive strength change characteristic is excellent, and it has a stable arrangement between the monomers, so that the adhesive characteristic is excellent. can That is, the second polymer exhibits a melting temperature (Tm) behavior, and is particularly excellent in the change characteristics of the initial and late adhesion strength, and has a more stable arrangement between the monomers after the heat treatment process, so that the adhesion characteristic is particularly excellent. .

In an exemplary embodiment of the present application, the unit derived from the monomer represented by Formula 1 included in the second polymer may be one type.

In the exemplary embodiment of the present application, there may be one or more units derived from the monomer represented by Formula 1 included in the second polymer.

In an exemplary embodiment of the present application, the unit derived from the monomer represented by Formula 1 included in the second polymer may be one or more and three or less.

In the exemplary embodiment of the present application, there may be two types of units derived from the monomer represented by Formula 1 included in the second polymer.

That is, the second polymer may be a homopolymer having one type of unit derived from the monomer represented by Formula 1 included in the second polymer, and a copolymer having one or more units derived from the monomer represented by Formula 1 above. (copolymer).

In the exemplary embodiment of the present application, when the second polymer includes one type of unit derived from the monomer represented by Formula 1, n in Formula 1 provides a pressure-sensitive adhesive composition that is 14 or more.

In another exemplary embodiment, when the second polymer includes one unit derived from the monomer represented by Formula 1, n in Formula 1 may be 14 or more, 30 or less, preferably 25 or less can

In the exemplary embodiment of the present application, when the second polymer includes two types of units derived from the monomer represented by Formula 1, n of one monomer represented by Formula 1 is 5 or more, and the other The n of the monomer may be 14 or more.

In another exemplary embodiment, when the second polymer includes two types of units derived from the monomer represented by Formula 1, n of one monomer represented by Formula 1 is 5 or more and 30 or less, the other one n of the monomer may be 14 or more and 30 or less.

In the exemplary embodiment of the present application, when the unit derived from the monomer represented by Formula 1 is a copolymer of one or more types, n in Formula 1 may satisfy an integer value of 5 or more. That is, compared to the case of a homopolymer in which the unit derived from the monomer represented by Chemical Formula 1 is one type, when it has a copolymer form, the range of the n value of Chemical Formula 1 is wider even if it is distributed later. It has the characteristics that the variable properties of the film can be expressed.

When the second polymer is a copolymer, it includes a unit derived from the monomer represented by Formula 1 having a long alkyl chain, so that the monomer represented by Formula 1 may be further included. Since the length of the alkyl chain of the unit derived from

In an exemplary embodiment of the present application, the glass transition temperature (Tg, glass transition) of the second polymer provides a pressure-sensitive adhesive composition that is less than 40 ℃.

In another exemplary embodiment, the glass transition temperature (Tg, glass transition) of the second polymer is less than 40 ℃, preferably provides a pressure-sensitive adhesive composition that is less than 35 ℃.

In another exemplary embodiment, the glass transition temperature (Tg, glass transition) of the second polymer is -200 ℃ or more, and provides a pressure-sensitive adhesive composition that is preferably -150 ℃ or more.

As the pressure-sensitive adhesive composition according to an exemplary embodiment of the present application includes a second polymer having a glass transition temperature in the above range including at least one unit derived from the monomer represented by Formula 1 in the pressure-sensitive adhesive composition, it is included later Since the initial adhesive strength of the adhesive sheet is low, it is initially adhered to the substrate to be adhered and has a feature that can provide a reworkable adhesive film in the event of erroneous adhesion such as generation of bubbles and foreign substances.

In an exemplary embodiment of the present application, the (meth)acrylate-based first polymer may have a weight average molecular weight of 100,000 g/mol to 5 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 weight of the molecular species of the component molecular weight of the 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, as 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 monomer 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 monomer include (meth)acrylic acid, 2-(meth)acryloyloxyacetic acid, 3-(meth)acryloyloxypropyl acid, 4-(meth)acryloyloxybutyric acid, acrylic acid duplex, itaconic acid, maleic acid, or maleic anhydride; and the like.

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 (meth)acrylate-based first polymer may have a glass transition temperature value of 0° C. or less.

In another exemplary embodiment, the glass transition temperature value of the (meth)acrylate-based first polymer is -110°C or more and 0°C or less, preferably -100°C or more and 0°C or less, more preferably -90°C. It may be more than 0°C or less.

When the glass transition temperature value of the (meth)acrylate-based first polymer is within the above range, the adhesive strength increases during a subsequent heat treatment process. When the glass transition temperature (Tg) of the first polymer is greater than 0° C., it is difficult for the polymer to flow, and the increase in adhesive strength may decrease over time.

In the present specification, the glass transition temperature is determined by using a differential scanning calorimeter (DSC, Mettler), and when a sample of about 10 mg is sealed in a dedicated pan and heated to a constant temperature environment, the endothermic heat of the material due to the phase change occurs and the calorific value measured by plotting the calorific value according to the 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 above general formula (1), Tg is the glass transition temperature of polymer A (unit: K), Tgi (i = 1, 2, ... n) is the glass transition temperature (unit: n) when the monomer i forms a homopolymer. : 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 an exemplary embodiment of the present application, the acrylic first polymer may include 50 to 80 parts by weight of an alkyl acrylate, 5 to 40 parts by weight of an alkyl methacrylate, and 1 to 30 parts by weight of a hydroxyalkyl acrylate.

Meaning that the acrylic first polymer contains 50 to 80 parts by weight of an alkyl acrylate, 5 to 40 parts by weight of an alkyl methacrylate, and 1 to 30 parts by weight of a hydroxyalkyl acrylate, an alkyl acrylate monomer, an alkyl methacrylate It means that the monomer and the hydroxyalkyl acrylate monomer are polymerized in the above weight ratio.

In the exemplary embodiment of the present application, the acrylic first polymer may include 50 to 80 parts by weight of an alkyl acrylate, preferably 55 to 80 parts by weight, and more preferably 60 to 70 parts by weight.

In the exemplary embodiment of the present application, the acrylic first polymer may include 5 to 40 parts by weight of alkyl methacrylate, preferably 7 to 35 parts by weight, and more preferably 10 to 30 parts by weight.

In the exemplary embodiment of the present application, the acrylic first polymer may include 1 to 30 parts by weight of hydroxyalkyl acrylate, preferably 5 to 25 parts by weight, and more preferably 5 to 20 parts by weight.

The alkyl acrylate and alkyl methacrylate are monomers having an alkyl group having 1 to 12 carbon atoms, pentyl (meth) acrylate, n-butyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylic rate, hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate and decyl (meth) acrylate It may include one or more than one of them.

Examples of the hydroxyalkyl acrylate include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, 8-hydroxyoctyl acrylate, 2 -Hydroxyethylene glycol acrylate, 2-hydroxypropylene glycol acrylate, etc. are mentioned.

In the exemplary embodiment of the present application, the content of the second polymer may be 0.1 parts by weight to 20 parts by weight based on 100 parts by weight of the first polymer.

In another exemplary embodiment, the content of the second polymer may include 0.5 to 17 parts by weight, preferably 1 to 13 parts by weight, based on 100 parts by weight of the first polymer.

When the first polymer and the second polymer are in the above weight ratio range, rework is easy due to a low initial adhesive strength when bonding to an adherend substrate, and has a high adhesive strength after a heat treatment process.

In the exemplary embodiment of the present application, the content of the unit derived from the monomer represented by Formula 2 or Formula 3 may include 1 part by weight to 70 parts by weight based on 100 parts by weight of the second polymer.

In another exemplary embodiment, the content of the unit derived from the monomer represented by Formula 2 or 3 is 1 part by weight to 50 parts by weight, preferably 1 part by weight to 30 parts by weight, based on 100 parts by weight of the second polymer. may include

In another exemplary embodiment, the content of the unit derived from the monomer represented by Formula 2 may include 1 part by weight to 50 parts by weight, preferably 1 part by weight to 30 parts by weight, based on 100 parts by weight of the second polymer. can

In an exemplary embodiment of the present application, the content of the unit derived from the monomer represented by Formula 1 may include 30 parts by weight to 99 parts by weight based on 100 parts by weight of the second polymer.

In another exemplary embodiment, the content of the unit derived from the monomer represented by Formula 1 may include 35 parts by weight to 95 parts by weight, preferably 35 parts by weight to 90 parts by weight, based on 100 parts by weight of the second polymer. can

When the content of the unit derived from the monomer represented by Formula 1 and the unit derived from the monomer represented by Formula 2 with respect to the second polymer has the above range, rework with low initial adhesion when bonding to an adherend substrate ( It is easy to rework) and has the effect of having high adhesive strength after the heat treatment process.

The second polymer may further include at least one unit derived from the monomer represented by Formula 1 and a monomer other than a unit derived from the monomer represented by Formula 2, wherein the monomer is the above-described (meth)acryl. rate may be included.

In an exemplary embodiment of the present application, the pressure-sensitive adhesive composition may further include one or more selected from the group consisting of a solvent, a dispersant, a photoinitiator, a thermal initiator, and a tackifier.

In an exemplary embodiment of the present application, the crosslinking agent may include a crosslinking compound, and the crosslinking agent may use an isocyanate-based crosslinking agent, and those known in the art may be used.

According to an exemplary embodiment of the present specification, the crosslinkable 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 a 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 Corporation of 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 Ciba Geigy's Irgacure OXE 01 and Irgacure OXE 02; 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.

Toluene may be used as the solvent, but is not limited thereto as long as it can dissolve a specific material, and a general organic solvent may be used accordingly.

An exemplary embodiment of the present application is a base film; And it is provided on one surface on the base film, to provide an adhesive film comprising a pressure-sensitive adhesive composition or a cured product according to the present application comprising a pressure-sensitive adhesive sheet.

In an exemplary embodiment of the present application, the initial adhesive force after bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate) at 23° C. for 2 hours is 100 gf/inch or less, and then It provides an adhesive film having a late adhesive strength of 300 gf/inch or more after heat treatment at 50° C. for 20 minutes.

The initial adhesive force and the late adhesive force were measured using a texture analyzer (Texture analyzer (Stable Micro Systems)) at a 180° angle and a peeling speed of 300 mm/min, and the adhesive sheet according to the present invention was measured by 1 inch. After cutting to size, it was attached to a stainless steel (SUS304) substrate by reciprocating once with a 2 kg rubber roller, and then measured for each.

That is, the initial adhesive strength is measured by cutting the adhesive sheet according to the present invention to a size of 1 inch, and then attaching it to a stainless steel (SUS304) substrate by reciprocating it once with a 2 kg rubber roller and leaving it at 23° C. for 2 hours, then at an angle of 180° and peeling at a peeling rate of 300 mm/min, meaning a value measured using a texture analyzer (Stable Micro Systems).

After the adhesive sheet according to the present invention is cut to a size of 1 inch, the adhesive sheet is attached to a stainless steel (SUS304) substrate by reciprocating once with a 2 kg rubber roller, and left at 23° C. for 2 hours, and then at 50° C. After 20 minutes of heat treatment at 180° angle and peeling speed of 300 mm/min, it is peeled off, and means the value measured using a texture analyzer (Stable Micro Systems).

In an exemplary embodiment of the present application, the initial adhesive force after bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to a stainless (SUS304) substrate at 23° C. for 2 hours is 100 gf/inch or less, preferably may be 90 gf/inch or less, more preferably 85 gf/inch or less.

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

In an exemplary embodiment of the present application, after bonding the opposite surface of the surface in contact with the base film of the pressure-sensitive adhesive sheet to a stainless (SUS304) substrate, leaving it at 23°C for 2 hours, and then heat-treating it at 50°C for 20 minutes The post adhesive strength after 2 hours may be 300 gf/inch or more, preferably 400 gf/inch or more, and more preferably 500 gf/inch or more.

In another exemplary embodiment, the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet is left at 23° C. for 2 hours after bonding to a stainless steel (SUS304) substrate, and then after heat treatment at 50° C. for 20 minutes 2 The post adhesion after time may be 3000 gf/inch or less, preferably 2800 gf/inch or less, and more preferably 2500 gf/inch or less.

The pressure-sensitive adhesive film according to the present application includes one or more units derived from the monomer represented by Formula 1 in the pressure-sensitive adhesive sheet as described above, so that even after 2 hours at room temperature (23° C.), the adhesive strength is constantly at a low level. It is characterized in that since it has a property to be maintained, no dirt remains even if it is removed during misadhesion, and the adhesive strength with the substrate to be adhered is increased by increasing the adhesive force through a specific process thereafter.

In an exemplary embodiment of the present application, the stainless steel substrate is a SUS304 substrate, a substrate corresponding to a surface type called No. 8, a polished surface with high gloss and reflective function, and a buff is rotated with an abrasive of #800 or higher It is a substrate having a surface made by grinding and polishing.

In an exemplary embodiment of the present application, the late adhesive force is 3 times or more and 100 times or less, preferably 5 times or more and 100 times or less, more preferably 10 times or more and 100 times or less of the initial adhesive force. do.

In an exemplary embodiment of the present application, the thickness of the pressure-sensitive adhesive sheet is 3 μm or more and 500 μm or less, preferably 5 µm or more and 400 µm or less, and more preferably 7 µm or more and 200 µm or less.

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 behind.

In the exemplary embodiment of the present application, the base film 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).

In an exemplary embodiment of the present application, the thickness of the base film is 25 μm or more and 300 μm or less, preferably 30 µm or more and 270 µm or less, and more preferably 40 µm or more and 250 µm or less.

In addition, it is preferable that the said base film is transparent. The meaning that the base film here is transparent shows that the light transmittance of visible light (400 nm - 700 nm) is 80% or more.

When the thickness of the base film 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 adhesive film is 110 μm or more and 700 μm It provides the following adhesive films.

In another exemplary embodiment, the thickness of the pressure-sensitive adhesive film is 120 μm or more and 600 μm or less, preferably 125 µm or more and 550 µm or less, more preferably 130 µm or more and 500 µm may be below.

Since the pressure-sensitive adhesive film has the above range, it has a suitable thickness when applied to a plastic organic light emitting display in the future, and has a characteristic that adhesive strength does not decrease when applied to a display.

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

In an exemplary embodiment of the present application, it provides an adhesive film that further comprises a release film on the opposite side of the surface in contact with the base film of the adhesive sheet.

To include a release film on one surface of the pressure-sensitive adhesive sheet means that the release film is provided on the opposite side of the surface of the pressure-sensitive adhesive sheet in contact with the base film.

In an exemplary embodiment of the present application, the release film may be a hydrophobic film, and as a layer for protecting a very thin pressure-sensitive adhesive sheet, refers to a transparent layer attached to one surface of the pressure-sensitive adhesive sheet, mechanical strength, thermal stability , a film having excellent moisture barrier properties, 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 triacetylcellulose (TAC) may be used, but is not limited thereto, as long as it is a commercially available silicone-treated release film.

2 is a diagram illustrating a laminated structure of an adhesive film including a release film according to an exemplary embodiment of the present application. Specifically, it can be seen that the adhesive film 40 has a structure in which the base film 10 / the adhesive sheet 20 / the release film 30 are sequentially stacked.

All of the release film may be removed when applied to a display.

In an exemplary embodiment of the present application, the step of preparing a base film; and applying and curing the pressure-sensitive adhesive composition according to the present application on one surface of the base film to form a pressure-sensitive adhesive sheet,

After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after standing at 23° C. for 2 hours is 100 gf/inch or less, and then after heat treatment at 50° C. for 20 minutes An object of the present invention is to provide a method for manufacturing an adhesive film having an adhesive strength of 300 gf/inch or more.

In an exemplary embodiment of the present application, after the step of forming the pressure-sensitive adhesive sheet on one surface on the base film, there is provided a method of manufacturing the pressure-sensitive adhesive film further comprising the step of drying the pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive sheet may be formed by coating the above-described pressure-sensitive adhesive composition on the base film and drying, then covering the release sheet again on the coated surface and aging it at 40° C. for 2 days or more.

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

An exemplary embodiment of the present application is an adhesive film according to the present application; a plastic substrate provided on the adhesive sheet side of the 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 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 several different forms and is not limited to the embodiments described herein.

< production example >

< production example 1> polymerization of the first polymer

For Examples 1 to 3 and Comparative Examples 1 to 5, ethylhexyl acrylate (EHA, Ehylhexylacrylate) / methyl methacrylate (MMA, Methylmethacrylate) / hydroxyethyl acrylate (HEA, hydroxyethylacrylate) was 65/ After being added to ethyl acetate (EA, Ethyl Acetate) in a weight ratio of 20/15, azobisisobutyronitrile (AIBN), a thermal polymerization initiator, was added, and a (meth)acrylate-based resin having a weight average molecular weight of 1 million g/mol was prepared.

< production example 2> polymerization of the second polymer

After the material having the second polymer composition and weight ratio of Table 1 was added to toluene, AIBN (azobisisobutyronitrile), a thermal polymerization initiator, was added to prepare a polymer having a weight average molecular weight of 60,000 g/mol.

In Table 1 below, FM0721 is a monofunctional polysiloxane manufactured by Chisso, and FM0721 is a (meth)acrylate in which polysiloxane is present.

In Table 1 below, BYK-377 and OFX-0400 have a structure used as a general additive, and products of BYK and DOW were used, respectively.

FM0721 has a structure containing polymerizable (meth)acrylate and can react with other monomers, but the structures of BYK-377 and OFX-0400 are simple additives that cannot be polymerized.

< production example 3> Preparation of pressure-sensitive adhesive composition

After adding 1 part by weight of an isocyanate crosslinking agent (Samyoung Ink Co., Ltd. DR7030HD) to 100 parts by weight of the (meth)acrylate-based resin prepared in Preparation Example 1, the polymer prepared in Preparation Example 2 was prepared in Table 1 below. After adding in a proportion by weight of , the pressure-sensitive adhesive composition was prepared by diluting it with a toluene solution so that the solid content was 20%.

The adhesive composition prepared in Preparation Example 3 was coated to a thickness of 15 μm on a polyethylene terephthalate (PET) film (T91455) treated with MPI’s double-sided anti-static (AS), and both-sided static electricity prevention (Anti-static, AS) After applying the treated polyethylene terephthalate (Polyethylene terephthalate, PET) (RF12AS), aging at 40 ℃ 2 days (Aging) to prepare a pressure-sensitive adhesive sheet.

first polymer
(weight ratio) second polymer Monomer (weight ratio) Jungnangbu Example 1 EHA/MMA/HEA
(65/20/15) Vinyl stearate/FM-0721
(80/20) 5 Example 2 EHA/MMA/HEA
(65/20/15) Vinyl palmitate/FM-0721
(80/20) 5 Example 3 EHA/MMA/HEA
(65/20/15) Vinyl decanoate/Vinyl stearate/FM-0721
(20/60/20) 5 Comparative Example 1 EHA/MMA/HEA
(65/20/15) BYK-377 0.1 Comparative Example 2 EHA/MMA/HEA
(65/20/15) OFX-0400 0.1 Comparative Example 3 EHA/MMA/HEA
(65/20/15) Vinyl butyrate/FM-0721
(80/20) 5 Comparative Example 4 EHA/MMA/HEA
(65/20/15) Vinyl Hexanoate/FM-0721
(80/20) 5 Comparative Example 5 EHA/MMA/HEA
(65/20/15) Vinyl neo-decanoate/Vinyl stearate/FM-0721
(20/60/20) 5

The results of measuring the initial adhesive force (gf/inch) and the later adhesive force (gf/inch) of Examples 1 to 3 and Comparative Examples 1 to 5 are shown in Table 2 below.

Initial adhesion (gf/inch) Late Adhesion (gf/inch) Example 1 71 1683 Example 2 75 1512 Example 3 83 1538 Comparative Example 1 95 172 Comparative Example 2 98 188 Comparative Example 3 85 170 Comparative Example 4 91 188 Comparative Example 5 118 254

In Table 2, the initial adhesive force and the later adhesive force were measured using a texture analyzer (Stable Micro Systems, Inc.) at a 180° angle and a peeling rate of 300 mm/min, and the adhesive sheet prepared by the present invention was subjected to 2 kg rubber After attaching to a stainless steel (SUS304) substrate by reciprocating with a roller, measurements were made after the initial 2 hours and 2 hours after the heat treatment. The initial adhesive strength was measured after cutting the adhesive sheet according to the present invention to a size of 1 inch. , attached to a stainless steel (SUS304) substrate by reciprocating with a 2kg rubber roller and left at 23℃ for 2 hours, peeled at a 180° angle and at a peeling rate of 300mm/min, using a texture analyzer (Stable Micro Systems) was measured using

After the adhesive sheet according to the present invention is cut to a size of 1 inch, the adhesive sheet is attached to a stainless steel (SUS304) substrate by reciprocating once with a 2 kg rubber roller, and left at 23° C. for 2 hours, and then at 50° C. After 20 minutes of heat treatment in a , peeling at an angle of 180° and a peeling rate of 300 mm/min after 2 hours was measured using a texture analyzer (Stable Micro Systems).

As can be seen from Table 2, the alkyl part of the unit derived from the monomer represented by Chemical Formula 1 according to the present application has a long chain alkyl group structure, and in this case, a short chain with a small number of carbon atoms. It was confirmed that the change characteristics of the initial and late adhesion strength were particularly superior to those of the monomer having an alkyl group. After the heat treatment process, a more stable arrangement between the monomers is obtained, so that the adhesive property is particularly excellent.

Specifically, in Examples 1 and 2 of Table 2, the n value of the monomer represented by Formula 1 included in the second polymer has a value of 5 or more, and in Example 3 of Table 2, the first agent 2 When the monomer represented by Formula 1 contained in the polymer is in the form of a copolymer of two or more types, in the case of Examples 1 to 3, the glass transition temperature (Tg) value of the second polymer is less than 40° C. have a value

Compared to the case of Comparative Examples 3 and 4 (a homomonomer having an n value of less than 5) and Comparative Example 5 (when the monomer has a unit amount not corresponding to Chemical Formula 1) in Table 2, Example 1 according to the present application In the case of 3 to 3, it was confirmed that the variable characteristics were excellent, and accordingly, the initial adhesive strength of the adhesive sheet was low, so that it was initially adhered to the adherend substrate and reworked when erroneous adhesion such as bubbles and foreign matter generated, and heat was applied. After the treatment process, it was confirmed that the adhesive strength with the substrate to be adhered was high.

10: base film
20: adhesive sheet
30: release film
40: adhesive film

Claims (19)

(meth)acrylate-based first polymer;
a second polymer comprising at least one unit derived from a monomer represented by the following formula (1), and including a unit derived from a monomer represented by the following formula (2) or formula (3); and
crosslinking agent;
A pressure-sensitive adhesive composition comprising:
[Formula 1]

[Formula 2]

[Formula 3]

In Formulas 1 to 3,
R ₁ is hydrogen; or a methyl group,
R ₂ is hydrogen; or an alkyl group,
R ₃ is a monofunctional acrylate,
m is an integer from 0 to 200,
n is an integer from 5 to 30; The method according to claim 1,
The second polymer is a pressure-sensitive adhesive composition comprising at least one unit derived from the monomer represented by the formula (1) and a unit derived from the monomer represented by the formula (2). The method according to claim 1,
When the second polymer includes one type of unit derived from a monomer represented by Formula 1, n in Formula 1 is 14 or more. The method according to claim 1,
The glass transition temperature (Tg, glass transition) of the second polymer is less than 40 ℃ pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition of claim 1, wherein the content of the second polymer is 0.1 parts by weight to 20 parts by weight based on 100 parts by weight of the first polymer. The pressure-sensitive adhesive composition according to claim 1, wherein the content of the unit derived from the monomer represented by Formula 2 or Formula 3 is 1 part by weight to 70 parts by weight based on 100 parts by weight of the second polymer. The pressure-sensitive adhesive composition according to claim 1, wherein the content of the unit derived from the monomer represented by Formula 1 is 30 parts by weight to 99 parts by weight based on 100 parts by weight of the second polymer. The method according to claim 1, wherein the (meth) acrylate-based first polymer is based on 100 parts by weight of the first polymer.
50 to 80 parts by weight of an alkyl acrylate;
5 to 40 parts by weight of an alkyl methacrylate, and
A pressure-sensitive adhesive composition comprising 1 to 30 parts by weight of hydroxyalkyl acrylate. The pressure-sensitive adhesive composition of claim 1, wherein the pressure-sensitive adhesive composition further comprises at least one selected from the group consisting of a solvent, a dispersant, a photoinitiator, a thermal initiator, and a tackifier. base film; and
A pressure-sensitive adhesive sheet provided on one surface of the base film and comprising the pressure-sensitive adhesive composition according to any one of claims 1 to 9 or a cured product thereof;
An adhesive film comprising a. The pressure-sensitive adhesive film of claim 10, further comprising a release sheet on a surface opposite to the surface of the pressure-sensitive adhesive sheet in contact with the base film. The method according to claim 10, wherein the initial adhesive strength after bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate) at 23°C for 2 hours is 100 gf/inch or less, and then 20 at 50°C An adhesive film having a post-adhesive strength of 300 gf/inch or more after a minute heat treatment. The adhesive film according to claim 12, wherein the late adhesive force is 3 times or more and 100 times or less of the initial adhesive force. The method according to claim 10, wherein the pressure-sensitive adhesive sheet has a thickness of 3 μm or more and 500 μm The adhesive film which is the following. The method according to claim 10, wherein the thickness of the base film is 25 μm or more and 300 μm The adhesive film which is the following. The method according to claim 10, wherein the base film is PET (polyethylene terephthalate), polyester (polyester), PC (polycarbonate), PI (polyimide), PEN (polyethylene naphthalate), PEEK (polyether ether ketone), PAR (polyarylate), PCO (polycylicolefin), polynorbornene (polynorbornene), PES (polyethersulphone), and COP (cycloolefin polymer) will be selected from the group consisting of an adhesive film. preparing a base film; and
Forming a pressure-sensitive adhesive sheet by applying and curing the pressure-sensitive adhesive composition according to any one of claims 1 to 9 on one surface of the base film;
A method for producing an adhesive film comprising:
After bonding the opposite side of the surface in contact with the base film of the pressure-sensitive adhesive sheet to stainless steel (SUS304 substrate), the initial adhesive strength after standing at 23°C for 2 hours is 100 gf/inch or less, and then after heat treatment at 50°C for 20 minutes A method for producing an adhesive film having an adhesive strength of 300 gf/inch or more. 18. The method of claim 17,
After the step of forming the pressure-sensitive adhesive sheet on one surface on the base film, the method for producing an adhesive film further comprising the step of drying the pressure-sensitive adhesive sheet. The adhesive film according to claim 10;
a plastic substrate provided on the adhesive sheet side of the 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.

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