KR102235978B1 - Adhesive sheet for polarizing plate protecting film, polarizing plate comprising same and display device comprising same - Google Patents

Abstract

Adhesive film; And a polarizing plate protective film provided on the adhesive film, wherein the adhesive film includes an acrylate resin; Li-containing inorganic salt; Ionic liquid antistatic agents; And a composition containing polydimethylsiloxane or a cured product thereof, wherein the Li-containing inorganic salt contains 0.01 parts by weight or more and 0.12 parts by weight or less based on 100 parts by weight of the acrylate resin, and the acrylic substrate of the adhesive film It is intended to provide a pressure-sensitive adhesive sheet, a polarizing plate including the same, and a display device including the same, wherein the peeling force for the adhesive sheet satisfies Equation 1.

Description

Adhesive sheet for a polarizing plate protective film, a polarizing plate including the same, and a display device including the same {ADHESIVE SHEET FOR POLARIZING PLATE PROTECTING FILM, POLARIZING PLATE COMPRISING SAME AND DISPLAY DEVICE COMPRISING SAME}

The present application relates to an adhesive sheet for a polarizing plate protective film, a polarizing plate including the same, and a display device including the same.

Conventionally, a pressure-sensitive adhesive sheet having a high adhesive strength from the initial stage of adhesion has been known. In addition, when using such an adhesive sheet to fix a substrate, an adhesive sheet having sufficient adhesive strength to fix the substrate is selected.

On the other hand, in the movement or storage of various polarizing plates or articles, the work of covering the surface with protective articles such as protective tapes, protective sheets, and protective films to prevent intrusion of dust or moisture into the interior of the precision instrument and to protect the surface. This is done.

In the case of a protective film, an adhesive film is generally provided to adhere to a member or article to be protected. In the case of this adhesive film, it is necessary to have high re-peelability so as not to contaminate the member or article to be protected.

However, if the protective film is stored for a long time or exposed to a high temperature environment after attaching the protective film, the peeling force of the protective film may increase with respect to the target article. Accordingly, when the protective film is removed, the target article is contaminated. Material may be left behind.

Therefore, there is a need for development of a protective film having antistatic properties without changing the peeling force even during high temperature storage or long-term storage.

Japanese Patent Publication No. 2006-299283

The present application is to provide an adhesive sheet for a polarizing plate protective film, a polarizing plate including the same, and a display device including the same.

An exemplary embodiment of the present application is an adhesive film; And a polarizing plate protective film provided on the adhesive film, wherein the adhesive film includes an acrylate resin; Li-containing inorganic salt; Ionic liquid antistatic agents; And a composition containing polydimethylsiloxane or a cured product thereof, wherein the Li-containing inorganic salt contains 0.01 parts by weight or more and 0.12 parts by weight or less based on 100 parts by weight of the acrylate resin, and the acrylic substrate of the adhesive film It provides a pressure-sensitive adhesive sheet that satisfies the following formula 1 for peeling force.

[Equation 1]

5 <(B/A-1)*100 <60

In Equation 1 above,

The A means a peeling force (gf/in) measured after bonding one side of the adhesive film to an acrylic substrate and then storing at 23°C for 4 hours,

B means a peeling force (gf/in) measured after bonding one side of the adhesive film to an acrylic substrate and then storing at 60° C. for 3 days.

In another embodiment, the polarizer; An adhesive layer provided on one or both sides of the polarizer; A polarizer protective film provided on a surface of the adhesive layer opposite to a surface in contact with the polarizer; And an adhesive sheet according to an exemplary embodiment of the present application provided on a surface opposite to a surface of the polarizer protective film in contact with the adhesive layer, the opposite surface of the surface of the polarizer protective film in contact with the adhesive layer, and the It provides a polarizing plate in which one surface of the adhesive film of the adhesive sheet is in contact.

In another embodiment, a liquid crystal panel; A first polarizing plate provided on any one surface of the liquid crystal panel; And a second polarizing plate provided on the other side of the liquid crystal panel, wherein at least one of the first polarizing plate and the second polarizing plate includes a polarizing plate according to an exemplary embodiment of the present application. to provide.

Finally, a display device including a polarizing plate according to an exemplary embodiment of the present application is provided.

The pressure-sensitive adhesive sheet according to an exemplary embodiment of the present application includes an acrylate-based resin in the pressure-sensitive adhesive film; Li-containing inorganic salt; Ionic liquid antistatic agents; And it has excellent antistatic properties including polydimethylsiloxane, and has a characteristic that the physical properties of the polarizing plate protective film are stably implemented.

In particular, the pressure-sensitive adhesive sheet according to an exemplary embodiment of the present application has a characteristic that the peel force with respect to the acrylic substrate is maintained constant, and there is little variation in peel force with respect to the initial peel force even when stored at high temperature/long time.

1 is a diagram showing a laminated structure of an adhesive sheet according to an exemplary embodiment of the present application.
2 is a diagram showing a laminated structure of an adhesive sheet according to an exemplary embodiment of the present application.
3 shows a stacked structure of a polarizing plate according to an exemplary embodiment of the present application.
4 is a diagram illustrating a stacked structure of a liquid crystal display 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 can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

An exemplary embodiment of the present application is an adhesive film; And a polarizing plate protective film provided on the adhesive film, wherein the adhesive film includes an acrylate resin; Li-containing inorganic salt; Ionic liquid antistatic agents; And a composition containing polydimethylsiloxane or a cured product thereof, wherein the Li-containing inorganic salt contains 0.01 parts by weight or more and 0.12 parts by weight or less based on 100 parts by weight of the acrylate resin, and the acrylic substrate of the adhesive film It provides a pressure-sensitive adhesive sheet that satisfies the following Equation 1 for peeling force.

[Equation 1]

5 <(B/A-1)*100 <60

In Equation 1 above,

The A means a peeling force (gf/in) measured after bonding one side of the adhesive film to an acrylic substrate and then storing at 23°C for 4 hours,

B means a peeling force (gf/in) measured after bonding one side of the adhesive film to an acrylic substrate and then storing at 60° C. for 3 days.

1 shows a laminated structure of an adhesive sheet according to an exemplary embodiment of the present application. Specifically, the adhesive sheet 103 may have a structure laminated with a polarizing plate protective film 101 / adhesive film 102.

The adhesive film according to an exemplary embodiment of the present application is an acrylate-based resin; Li-containing inorganic salt; Ionic liquid antistatic agents; And polydimethylsiloxane has excellent antistatic properties, and physical properties of the polarizing plate protective film can be stably implemented. In addition, as the pressure-sensitive adhesive film has the above properties, it has the property that the peeling force with respect to the substrate to be adhered can be kept constant even at high temperature/long time storage.

In the exemplary embodiment of the present application, the acrylic substrate may be PMMA (Polymethyl methacrylate).

It was confirmed that the pressure-sensitive adhesive sheet according to an exemplary embodiment of the present application has particularly excellent stability over high temperature compared to the case where it is used for a PET (polyethylene terephthalate) substrate or a TAC (triacetyl cellulose) substrate, especially when used for an acrylic substrate.

In an exemplary embodiment of the present application, an adhesive sheet further comprising a release film is provided on a surface opposite to a surface of the adhesive film where the polarizing plate protective film contacts.

The release film is a layer for protecting an adhesive film having a very thin thickness, and refers to a transparent layer attached to one side of the adhesive film, and a film having excellent mechanical strength, thermal stability, moisture shielding property, isotropic property, and the like 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), etc. It may be used, but is not limited thereto if it is a commercially available silicone-treated release film.

2 shows a laminated structure of an adhesive sheet according to an exemplary embodiment of the present application. Specifically, the adhesive sheet 103 may have a structure laminated with a polarizing plate protective film 101 / adhesive film 102 / release film 104, and when used for a polarizing plate later, the release film 104 may be removed and used. .

In the exemplary embodiment of the present application, A refers to a peeling force (gf/in) measured after bonding an acrylic substrate with an opposite surface of the adhesive film to the surface in contact with the polarizing plate protective film and then storing at 23°C for 4 hours. And, the A was measured using a texture analyzer (Texture Analyzer (Stable Micro Systems)) at a 180° angle and a peeling speed of 30 m/min, and the adhesive sheet prepared according to the present invention was measured once with a 2 kg rubber roller. This is the value measured after reciprocating and attaching to an acrylic substrate and storing at 23°C for 4 hours.

In the exemplary embodiment of the present application, B means peeling force (gf/in) measured after 3 days storage at 60° C. after bonding the opposite side of the adhesive film to the surface in contact with the polarizing plate protective film and the acrylic substrate And, the B was measured using a texture analyzer (Texture Analyzer (Stable Micro Systems)) at a 180° angle and a peeling speed of 30 m/min, and the adhesive sheet prepared according to the present invention was measured once with a 2 kg rubber roller. This is the value measured after reciprocating and attaching to an acrylic substrate and storing at 60°C for 3 days.

In the exemplary embodiment of the present application, A may be 10 gf/in or more and 80 gf/in or less.

In another exemplary embodiment, A is 15 gf/in or more and 80 gf/in or less, preferably 20 gf/in or more and 70 gf/in or less, more preferably 50 gf/in or more and 70 gf/in or less Can be

In the exemplary embodiment of the present application, B may be 50 gf/in or more and 100 gf/in or less.

In another exemplary embodiment, the B is 55 gf/in or more and 95 gf/in or less, preferably 60 gf/in or more and 95 gf/in or less, more preferably 65 gf/in or more and 95 gf/in or less Can be

In the present application, since the values of A and B have the above range, even when the polarizing plate protective film is removed from the substrate to be protected, contamination of the substrate to be protected does not occur.

In particular, since A and B have a value that satisfies the above [Equation 1], after bonding the polarizing plate protective film to the substrate to be protected, the peeling force is maintained constant even at high temperature/long time storage.

In the exemplary embodiment of the present application, the Li-containing inorganic salt may include 0.01 parts by weight or more and 0.1 parts by weight or less based on 100 parts by weight of the acrylate-based resin.

In another exemplary embodiment, the Li-containing inorganic salt is 0.01 parts by weight or more and 0.1 parts by weight or less, preferably 0.02 parts by weight or more and 0.1 parts by weight or less, more preferably 0.05 parts by weight based on 100 parts by weight of the acrylate resin. It may include parts by weight or more and 0.1 parts by weight or less.

When the Li-containing inorganic salt contains the weight part in the acrylate-based resin, the peeling force (gf/in) measured after storage at 23° C. for 4 hours on the acrylic substrate of the adhesive film may be kept low, Accordingly, it has a property that can be reused in case of mis-attachment.

In the exemplary embodiment of the present application, the Li-containing inorganic salt may be LiTFSI (trifluoromethane) sulfonimide lithium salt (LiTFSI).

In an exemplary embodiment of the present application, the polydimethylsiloxane provides a pressure-sensitive adhesive sheet containing 0.1 parts by weight or more and 0.8 parts by weight or less based on 100 parts by weight of the acrylate-based resin.

In another exemplary embodiment, the polydimethylsiloxane is 0.1 parts by weight or more and 0.8 parts by weight or less, preferably 0.2 parts by weight or more and 0.8 parts by weight or less, more preferably 0.3 parts by weight based on 100 parts by weight of the acrylate resin. It may contain more than 0.7 parts by weight or less.

When the polydimethylsiloxane is included in the acrylate-based resin in the weight part, the antistatic property is particularly excellent, and thus the amount of static electricity generated when the adhesive film is peeled off is small.

In an exemplary embodiment of the present application, the ionic liquid antistatic agent provides a pressure-sensitive adhesive sheet containing 0.1 parts by weight or more and 0.8 parts by weight or less based on 100 parts by weight of the acrylate-based resin.

In another exemplary embodiment, the ionic liquid antistatic agent is 0.1 parts by weight or more and 0.8 parts by weight or less, preferably 0.2 parts by weight or more and 0.8 parts by weight or less, more preferably 0.3 parts by weight based on 100 parts by weight of the acrylate-based resin. It may contain more than 0.7 parts by weight or less.

When the ionic liquid antistatic agent contains the weight part in the acrylate resin, the antistatic property is excellent even when the content of the inorganic salt containing Li is small, and thus the amount of static electricity generated when the adhesive film is peeled off is reduced. Will have.

In the exemplary embodiment of the present application, the ionic liquid antistatic agent may be an organic salt having an ammonium compound.

In the exemplary embodiment of the present application, the ionic liquid antistatic agent includes at least one cation selected from the group consisting of Pyridinium-based, Ammonium-based, Pyrrolidinium-based, Imidazolium-based, and Phosphonium-based; And at least one anion selected from the group consisting of _{BF 4} , PF _{6 and TFSI.}

In the exemplary embodiment of the present application, the ionic liquid antistatic agent may be FC-4400 of 3M.

Each component and content of the adhesive film can be detected by component analysis. Specifically, after dissolving the adhesive film in a solvent for analysis, the acrylate resin and the ionic liquid antistatic agent are analyzed through Gas Chromatography (GC) analysis. Component analysis is possible, Si components such as polydimethylsiloxane can be analyzed by NMR analysis, and inorganic salts containing Li can be analyzed by ICP (Inductively Coupled Plasma) analysis.

Ethanol, toluene, etc. may be used as the solvent for analysis, and the type is not limited as long as the adhesive film can be dissolved.

In the exemplary embodiment of the present application, the polarizing plate protective film is PET (polyethylene terephthalate), polyester, PC (polycarbonate), PI (polyimide), PEN (polyethylene naphthalate), PEEK (polyether ether ketone), PAR (polyarylate), PCO (polycylicolefin), polynorbornene (polynorbornene), PES (polyethersulphone) and COP (cycloolefin polymer) may be selected from the group consisting of.

In the exemplary embodiment of the present application, the thickness of the polarizing plate protective film is 10 μm or more and 1000 μm Hereinafter, preferably, it may be 15 µm or more and 500 µm or less, and more preferably 20 µm or more and 150 µm or less.

When the polarizing plate protective film has the above range, the adhesion to the polarizer protective film may be excellent, and the antistatic characteristics may be particularly excellent when the polarizer protective film is used after being adhered to the polarizer.

In the exemplary embodiment of the present application, the thickness of the adhesive film is 3 μm or more and 500 μm It provides an adhesive sheet which is the following.

In the exemplary embodiment of the present application, the thickness of the adhesive film is 3 μm or more and 250 μm Hereinafter, preferably, it may be 5 µm or more and 150 µm or less, and more preferably 7 µm or more and 50 µm or less.

When the thickness of the pressure-sensitive adhesive film is within the above range, the adhered substrate is not contaminated even when the high-temperature/long-time pressure-sensitive adhesive film is attached to the adhered substrate, and in particular, when removing the pressure-sensitive adhesive film, foreign matter is not left.

In the exemplary embodiment of the present application, the acrylate-based resin may include a (meth)acrylate-based resin having a weight average molecular weight of 100,000 g/mol to 5 million g/mol.

The weight average molecular weight is one of average molecular weights whose 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 can 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 monomer is not particularly limited, but examples thereof include 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 Hexyl (meth) acrylate, dodecyl (meth) acrylate, and may include one or two or more of decyl (meth) acrylate.

The crosslinkable functional group-containing monomer is not particularly limited, but may include, for example, one or more of a hydroxy 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, and 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, and acrylic acid. Sieve, itaconic acid, maleic acid, or maleic anhydride.

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 resin is an acrylic polymer containing a monomer having a functional group -OH provides a pressure-sensitive adhesive sheet.

In the exemplary embodiment of the present application, the adhesive film may further include at least one selected from the group consisting of a dispersant, a photoinitiator, a thermal initiator, a curing agent, a curing catalyst, a curing retardant, and a tackifier.

In the exemplary embodiment of the present application, the adhesive film may further include a curing agent, a curing catalyst, and a curing retardant.

In the exemplary embodiment of the present application, the curing agent may include at least one selected from the group consisting of HDI Trimer, HMDI (Hexamethylene diisocyanate), TDI (Toluene diisocyanate), IPDI (Isophorone diisocyanate), and XDI (Xylylene diisocyanate). It can be, but not limited to these, general ones known in the art may be used.

In the exemplary embodiment of the present application, the curing catalyst may include at least one selected from the group consisting of Iron (3) Acetylacetonate, DBTDL (Dibutyltin dilaurate), and Aluminum Acetylacetonate, but is not limited thereto, General ones known in the field can be used.

In the exemplary embodiment of the present application, the curing retardant may be Acetylacetone, but is not limited thereto, and general ones known in the art may be used.

In the exemplary embodiment of the present application, the curing agent may include 1 part by weight or more and 10 parts by weight or less, preferably 3 parts by weight or more and 8 parts by weight or less based on 100 parts by weight of the acrylate-based resin.

In the exemplary embodiment of the present application, the curing catalyst may include 0.01 parts by weight or more and 1 part by weight or less, preferably 0.03 parts by weight or more and 0.1 parts by weight or less based on 100 parts by weight of the acrylate-based resin.

In the exemplary embodiment of the present application, the curing retardant may include 5 parts by weight or more and 15 parts by weight or less, preferably 5 parts by weight or more and 10 parts by weight or less based on 100 parts by weight of the acrylate-based resin.

When the curing agent, the curing catalyst, and the curing retardant according to the present application are included in the above content range, the peel force characteristic, which is the required physical property of the pressure-sensitive adhesive sheet, can be met, and the pot life can be properly secured. The pot life refers to a time for mixing a curing agent or a solvent and maintaining a usable state in using the adhesive film.

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 Propylene glycol di(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate with the number of 2 to 14 Compounds obtained by esterifying polyhydric alcohols such as a mixture of pentaerythritol hexa(meth)acrylate (TO-2348, TO-2349, manufactured by Dong-A Synthetic Japan as a brand name) with α,β-unsaturated carboxylic acid; Compounds obtained by adding (meth)acrylic acid to a compound containing a glycidyl group such as trimethylolpropane triglycidyl ether acrylic acid adduct and bisphenol A diglycidyl ether acrylic acid adduct; An ester compound of a compound having a hydroxyl group or 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, and is not limited thereto and 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 benzope. It may be substituted with one or two or more substituents selected from the group consisting of non-based compounds.

Specifically, according to the exemplary embodiment of the present specification, the photoinitiator is 2,4-trichloromethyl-(4'-methoxyphenyl)-6-triazine, 2,4-trichloromethyl-(4'-me Toxystyryl)-6-triazine, 2,4-trichloromethyl-(pipelonyl)-6-triazine, 2,4-trichloromethyl-(3',4'-dimethoxyphenyl)-6 -Triazine, 3-{4-[2,4-bis(trichloromethyl)-s-triazine-6-yl]phenylthio}propanoic acid, 2,4-trichloromethyl-(4'-ethyl ratio Triazine 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 Oxy)-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-based compounds; O-acyloxime compounds such as Irgacure OXE 01 and Irgacure OXE 02 of Ciba Geigy; Benzophenone compounds such as 4,4'-bis(dimethylamino)benzophenone or 4,4'-bis(diethylamino)benzophenone; Thioxanthone compounds such as 2,4-diethyl thioxanthone, 2-chloro thioxanthone, 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 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, etc. may be used alone or in combination of two or more, but are not limited thereto.

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

In an exemplary embodiment of the present application, a polarizer; An adhesive layer provided on one or both sides of the polarizer; A polarizer protective film provided on a surface of the adhesive layer opposite to a surface in contact with the polarizer; And an adhesive sheet according to an exemplary embodiment of the present application provided on a surface opposite to a surface of the polarizer protective film in contact with the adhesive layer, the opposite surface of the surface of the polarizer protective film in contact with the adhesive layer, and the It provides a polarizing plate in which one surface of the polarizing plate protective film of the pressure-sensitive adhesive sheet is in contact.

Figure 3 relates to a polarizing plate 108 according to an exemplary embodiment of the present application, specifically, a polarizer 107 / adhesive layer 106 / polarizer protective film 105 / adhesive film 102 / polarizing plate protective film 101 ) Represents a sequentially stacked structure. 3 is a structure in which one surface of the polarizer 107 is laminated, and an adhesive layer 106/polarizer protective film 105/adhesive film 102 on the opposite surface of the surface in contact with the adhesive layer 106 of the polarizer 107 )/Polarizing plate protective film 101 may be further stacked sequentially.

In the exemplary embodiment of the present application, the polarizer is not particularly limited, and a polarizer well known in the art, for example, a film made of polyvinyl alcohol (PVA) containing iodine or a dichroic dye is used.

The polarizer vibrates in various directions and exhibits a characteristic capable of extracting only light vibrating in one direction from incident light. This property can be achieved by stretching iodine-absorbed poly vinyl alcohol (PVA) with strong tension. For example, more specifically, swelling of swelling by immersing a PVA film in an aqueous solution, dyeing with a dichroic material imparting polarization to the swollen PVA film, and stretching the dyed PVA film ) To form a polarizer through a stretching step of arranging the dichroic dye materials side by side in a stretching direction, and a complementary color step of correcting the color of the PVA film after the stretching step. However, the polarizing plate of the present invention is not limited thereto.

The adhesive that can be used is not particularly limited as long as it is known in the art. For example, there are water-based adhesives, one- or two-component polyvinyl alcohol (PVA)-based adhesives, polyurethane-based adhesives, epoxy-based adhesives, styrene butadiene rubber-based (SBR-based) adhesives, or hot melt adhesives. It is not limited to these examples.

In the exemplary embodiment of the present application, the polarizer protective film is a cycloolefin polymer (COP)-based film, an acrylic film, a triacetylcellulose (TAC)-based film, a cycloolefin copolymer (COC)-based film, a polynorbornene (PNB)-based film, and a PET (polyethylene)-based film. terephtalate)-based film may be made of any one or more.

In another embodiment, the polarizer protective film may be an acrylic film.

In an exemplary embodiment of the present application, a display device including the polarizing plate is provided.

The display device includes a touch panel, a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display (LCD), and a thin film transistor. Liquid Crystal Display, LCD-TFT).

Another exemplary embodiment of the present specification provides a liquid crystal display device including the polarizing plate.

The liquid crystal display may include a liquid crystal panel; A first polarizing plate provided on any one surface of the liquid crystal panel; And a second polarizing plate provided on the other side of the liquid crystal panel, wherein at least one of the first polarizing plate and the second polarizing plate includes a polarizing plate according to an exemplary embodiment of the present application. to provide.

4 is a diagram illustrating a stacked structure of a liquid crystal display 111 according to an exemplary embodiment of the present application. Specifically, a first polarizing plate in which a polarizer 107 / adhesive layer 106 / polarizer protective film 105 / adhesive film 102 / polarizing plate protective film 101 are sequentially stacked on one surface of the liquid crystal panel 109 is It is a stacked structure, and a second polarizing plate 110 is stacked on a surface of the liquid crystal panel 109 opposite to the surface in contact with the polarizer 107. Likewise, the second polarizing plate may have a structure in which a polarizer 107 / an adhesive layer 106 / a polarizer protective film 105 / an adhesive film 102 / a polarizing plate protective film 101 are sequentially stacked.

In the exemplary embodiment of the present application, the liquid crystal panel is an IPS (In Plane Switching) mode liquid crystal panel, a VA (Vertical Alignment) mode liquid crystal panel, a FFS (Fringe Field Switching) mode liquid crystal panel, or a TN (Twisted Nematic) mode liquid crystal panel. It may be, but is not limited thereto.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

< Manufacturing example >

(1) Preparation of pressure-sensitive adhesive composition

An acrylic polymer solution having a solid content concentration of about 40% was prepared by copolymerizing 2-ethylhexyl acrylate and 2-hydroxylethyl acrylate at a weight ratio of 95:5. Ethyl acetate was used as a solvent.

And, compared to 100 parts by weight of the solid content of the acrylic polymer solution, 5 parts by weight of an isocyanate compound (HDI trimer, product name: DR750HD), 7.5 parts by weight of a curing retardant (acetylacetone) and an iron compound having diketonate as a ligand (Fe(III) Acetylacetonete) 0.05 parts by weight, and an inorganic salt containing Li of Examples 1 to 3 and Comparative Examples 1 to 4 of Table 1, an ionic liquid antistatic agent, and a weight part of polydimethylsiloxane were uniformly blended to prepare a pressure-sensitive adhesive composition.

Li-containing inorganic salt
(Part by weight) Ionic liquid antistatic agent
(Part by weight) Polydimethylsiloxane
(Part by weight) Example 1 LiTFSI
(0.05) FC-4400
(0.5) PDMS
(0.5) Example 2 LiTFSI(0.07) FC-4400
(0.5) PDMS
(0.5) Example 3 LiTFSI(0.1) FC-4400
(0.5) PDMS
(0.5) Comparative Example 1 LiTFSI(0.15) FC-4400
(0.5) PDMS
(0.5) Comparative Example 2 LiTFSI(0.2) FC-4400
(0.5) PDMS
(0.5) Comparative Example 3 LiTFSI(0.2) FC-4400
(0.5) PDMS
(One) Comparative Example 4 LiTFSI(0.0.5) - -

In Table 1, the LiTFSI and FC-4400 are products of 3M's Li-containing inorganic salt and an ionic liquid antistatic agent, and the PDMS used Momentive's L-7200.

(2) Preparation of adhesive sheet

The pressure-sensitive adhesive composition prepared in the composition and content of Table 1 was bar-coated on one side of PET (poly(ethylene terephthalate)) and dried at 120° C. for 1 minute. Immediately after drying, the release film was laminated and cured at 40° C. for 48 hours to prepare an adhesive sheet including an adhesive film having a thickness of 15 μm.

Peeling force A (gf/in) and peeling force B (gf /in), peel force change rate, ESD, and the results of measuring contamination are shown in Table 2 below.

A
(gf/in) B
(gf/in) Peel force change rate
(%) ESD
(Kv) Contamination Example 1 60 68 13 0.07 OK Example 2 61 73 19 0.07 OK Example 3 64 91 42 0.12 OK Comparative Example 1 72 128 77 0.13 OK Comparative Example 2 79 149 88 0.12 OK Comparative Example 3 65 88 35 0.16 NG Comparative Example 4 82 98 19 1.34 OK

1. Peel force A (gf/in): After laminating the prepared pressure-sensitive adhesive sheet on an acrylic substrate, the measured peel force (gf/in) was measured after storage at 23° C. for 4 hours.

2. Peeling force B (gf/in): It refers to the peeling force (gf/in) measured after laminating the prepared adhesive sheet on an acrylic substrate and then storing it at 60° C. for 3 days.

3. ESD (Electrostatic Discharge): ESD is a peeling voltage measured when peeling the protective film. It was measured using the STATIRON DZ-4 model of SHISHIDO, and the measurement distance from the sample was fixed at 3cm. The peeling speed of the pressure-sensitive adhesive sheet is 30 m/min and the peeling angle is 180°, which means a peeling electrification voltage (Kv) generated while peeling the pressure-sensitive adhesive sheet from the acrylic substrate.

4. Contamination: The adhesive sheet prepared on an acrylic substrate was laminated and left at 50° C. for more than one day, and Black Tape was laminated on the opposite side of the adhesive sheet to ensure visibility of contamination evaluation. Then, the pressure-sensitive adhesive sheet was repeatedly peeled/attached from the acrylic substrate to artificially mix air bubbles, and then left at room temperature for one or more days. After the pressure-sensitive adhesive sheet containing air bubbles was heat-treated at 50° C. for 3 hours, it was visually checked for contamination. If the bubble mark was not observed with the naked eye, it was marked as OK, and if the bubble mark was observed with the naked eye, it was classified as NG.

The peeling force A refers to the peeling force (gf/in) measured after bonding the opposite surface of the adhesive film to the surface in contact with the polarizing plate protective film and the acrylic substrate and stored at 23°C for 4 hours, and A is 180° It was measured using a texture analyzer (Stable Micro Systems) at an angle and a peel rate of 30 mm/min, and the adhesive sheet prepared according to the present invention was reciprocated once with a 2 kg rubber roller and attached to an acrylic substrate. This is the value measured after storage at 23°C for 4 hours.

The peeling force B refers to the peeling force (gf/in) measured after bonding the opposite surface of the adhesive film to the surface in contact with the polarizing plate protective film and the acrylic substrate and stored at 60° C. for 3 days, and B is 180° It was measured using a texture analyzer (Stable Micro Systems) at an angle and a peel rate of 30 mm/min, and the adhesive sheet prepared according to the present invention was reciprocated once with a 2 kg rubber roller and attached to an acrylic substrate. It is a value measured after storage at 60℃ for 3 days.

As can be seen from Table 2, the adhesive film according to an exemplary embodiment of the present application includes an acrylate resin in the adhesive film; Li-containing inorganic salt; Ionic liquid antistatic agents; And by including the polydimethylsiloxane, it was confirmed that the peeling force at the time of attaching to the substrate to be adhered (acrylic substrate) is kept constant even after storage at high temperature/long time. Specifically, it was confirmed that the rate of change for the peel force B was 50% or less with respect to the peel force A.

As described above, since the peel force change rate has a value of 50% or less, it is easy to remove the adhesive sheet including the polarizing plate protective film according to the present application, and it has the characteristic that contaminants of the adhesive do not remain in the polarizer protective film of the polarizer. I could confirm.

In addition, as can be seen in Table 2, in the case of Comparative Example 4 in which the ionic liquid antistatic agent and polydimethylsiloxane were not contained, it was confirmed that the ESD value was higher than that of Examples 1 to 3 in which the ESD value was 1.34 Kv and 0.5 Kv or less. Accordingly, in the case of the pressure-sensitive adhesive composition of Comparative Example 4, it was confirmed that the amount of static electricity generated during peeling of the pressure-sensitive adhesive sheet was greater than that of Examples 1 to 3.

101: polarizing plate protective film
102: adhesive film
103: adhesive sheet
104: release film
105: polarizer protective film
106: adhesive layer
107: polarizer
108: polarizer
109: liquid crystal panel
110: second polarizing plate
111: liquid crystal display

Claims (13)

Adhesive film; And
A polarizing plate protective film provided on the adhesive film;
To the adhesive sheet containing
The adhesive film is an acrylate resin; Li-containing inorganic salt; Ionic liquid antistatic agents; And a composition comprising polydimethylsiloxane or a cured product thereof,
The Li-containing inorganic salt contains 0.01 parts by weight or more and 0.12 parts by weight or less based on 100 parts by weight of the acrylate-based resin,
0.1 parts by weight or more and 0.8 parts by weight or less of the polydimethylsiloxane based on 100 parts by weight of the acrylate-based resin,
The pressure-sensitive adhesive sheet of the pressure-sensitive adhesive film satisfies the following equation 1:
[Equation 1]
5 <(B/A-1) * 100 <60
In Equation 1 above,
The A refers to a peel force (gf/in) measured after bonding one side of the adhesive film to an acrylic substrate and then storing at 23°C for 4 hours,
B means a peeling force (gf/in) measured after bonding one side of the adhesive film to an acrylic substrate and then storing at 60° C. for 3 days. The method according to claim 1,
An adhesive sheet further comprising a release film on a surface opposite to the surface of the adhesive film in contact with the polarizing plate protective film. The method according to claim 1,
The B is 50 gf/in or more and 100 gf/in or less. The method according to claim 1,
The pressure-sensitive adhesive sheet that the ionic liquid antistatic agent is contained in an amount of 0.1 parts by weight or more and 1 part by weight or less based on 100 parts by weight of the acrylate-based resin. The method according to claim 1,
The thickness of the adhesive film is 3 μm or more and 500 μm The adhesive sheet which is the following The method according to claim 1,
The thickness of the polarizing plate protective film is 10 μm or more and 1000 μm The adhesive sheet which is the following. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive film further comprises at least one selected from the group consisting of a dispersant, a photoinitiator, a thermal initiator, a curing agent, a curing catalyst, a curing retardant, and a tackifier. The pressure-sensitive adhesive sheet according to claim 1, wherein the acrylate-based resin is an acrylic polymer containing a monomer whose functional group is -OH. delete The method according to claim 1,
The pressure-sensitive adhesive sheet that the ionic liquid antistatic agent is an organic salt having an ammonium compound. Polarizer;
An adhesive layer provided on one or both sides of the polarizer;
A polarizer protective film provided on a surface of the adhesive layer opposite to a surface in contact with the polarizer; And
A polarizing plate comprising the adhesive sheet of any one of claims 1 to 8 and 10 provided on a surface opposite to the surface of the polarizer protective film where the adhesive layer contacts,
A polarizing plate in which a surface opposite to a surface of the polarizer protective film in contact with the adhesive layer and one surface of the adhesive film of the adhesive sheet are in contact with each other. Liquid crystal panel; A first polarizing plate provided on any one surface of the liquid crystal panel; And a second polarizing plate provided on the other side of the liquid crystal panel,
At least one of the first polarizing plate and the second polarizing plate includes the polarizing plate according to claim 11. A display device comprising the polarizing plate according to claim 11.

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