KR102475814B1 - Pressure sensitive adhesive composition - Google Patents

Abstract

The present application relates to a pressure-sensitive adhesive composition and an optical laminate including the same. According to the present application, stable durability is ensured even at high temperatures, particularly at ultra-high temperatures of about 100 ° C. or higher, foaming in the pressure-sensitive adhesive layer is suppressed or prevented, and an optical laminate having excellent physical properties required for other optical laminates is provided. In addition, according to the present application, even when an adhesive is disposed adjacent to an electrode, an optical laminate in which corrosion of the electrode may be suppressed may be provided.

Description

Pressure-sensitive adhesive composition {PRESSURE SENSITIVE ADHESIVE COMPOSITION}

The present application relates to an optical laminate including an adhesive composition and an adhesive layer formed therefrom.

Various optical films such as polarizers are applied to various display devices such as LCD (Liquid Crystal Display) or OLED (Organic Light Emitting Diode). Such an optical film is generally attached to a display device with an adhesive. In this case, high reliability is required for the optical film and the pressure-sensitive adhesive. For example, optical films or adhesives used in navigation or vehicle displays are required to stably maintain performance even when maintained at very high temperatures for a long period of time.

A polarizing plate, which is a representative optical film, generally has a multilayer structure including a polarizer, which is an element exhibiting a polarization function, and a protective film that protects the polarizer. As a protective film for the polarizer, a so-called TAC (triacetyl cellulose)-based film is used. However, since the TAC film has high moisture permeability, moisture penetrates into the polarizer under high temperature and high humidity conditions, resulting in defects such as light leakage or warping. Due to this water permeation problem, a plan to replace the TAC film with a low moisture permeability film is being considered, but in the case of a low moisture permeability film having hydrophobicity, the adhesion between the adhesive and the substrate, that is, the keying force is low. have.

Meanwhile, in the case of a polarizing plate used in a vehicle display, an adhesive containing an acid monomer is used to secure cohesion through a reaction with a crosslinking agent and provide appropriate high-temperature reliability to the polarizing plate. Specifically, the acid-based monomer increases the hardness of the pressure-sensitive adhesive resin itself and increases the adhesive force due to the polarity of the acid-based monomer. However, the acid component may cause stains or touch defects by corroding, for example, the ITO of the LCD panel.

In addition, when a metal salt-containing conductive material is used in an adhesive to improve conductivity, since it is vulnerable to moisture, there is a problem in that visibility is reduced while a clouding phenomenon occurs.

One object of the present application is to address the problems of the prior art.

Another object of the present application is to provide an adhesive composition and an optical laminate.

The above and other objects of the present application can all be solved by the present application described in detail below.

In an example relating to the present application, the present application relates to an adhesive composition. The adhesive composition may be used to form an adhesive layer of an optical laminate including a polarizer. The adhesive composition and the adhesive layer provided according to the present application can solve the following problems of the prior art.

Specifically, when the low moisture permeability film forms an optical laminate together with the pressure-sensitive adhesive layer, the low moisture permeability and hydrophobicity of the low moisture permeability film easily cause foaming in the adhesive, especially under ultra-high temperature conditions of 100°C or higher. There are issues that cause it. That is, even when a low moisture permeability optical film is applied, a pressure-sensitive adhesive capable of suppressing foaming and providing stable durability is required.

As another problem, since the acrylic film has relatively difficult adhesion, adhesion between the polarizing plate having the low moisture permeability acrylic film and the pressure-sensitive adhesive, that is, keying force is not good. In particular, separation between the polarizing plate and the adhesive may occur under high temperature conditions, and when the polarizing plate is separated from the adherend, the adhesive is separated from the polarizer and remains on the adherend.

Considering these points, the pressure-sensitive adhesive composition of the present application is configured to improve adhesion, high-temperature durability, and keying force. More specifically, when the inventors of the present application use a pressure-sensitive adhesive composition containing a crosslinking agent of a specific structure and another crosslinking agent in a predetermined content range, the pressure-sensitive adhesive layer formed therefrom is resistant to deformation of adjacent structures (eg, low moisture permeability film or polarizer). As a result, even when the low moisture permeability optical film is applied to the optical laminate, it was confirmed that the foaming phenomenon can be suppressed or prevented while stably maintaining high-temperature durability.

The pressure-sensitive adhesive composition includes an adhesive polymer and at least two isocyanate compounds. Accordingly, the polymer may be included in the pressure-sensitive adhesive layer described below in a crosslinked state by a crosslinking agent such as an isocyanate compound. To this end, as will be described later, the adhesive polymer may include a crosslinkable or polar functional group-containing monomer unit.

In the present application, the pressure-sensitive adhesive composition simultaneously includes an aromatic isocyanate compound (B) and a non-aromatic isocyanate compound (C) as a crosslinking agent. The compound (C) is a compound derived from HDI (hexamethylene diisocyanate) and may have a structure described below. Specifically, the inventors of the present application have confirmed that the anchoring force can be improved by applying a compound (C) having a slower curing rate as a crosslinking agent in addition to an aromatic isocyanate compound such as TDI (toluene diisocyanate). Since the curing speed of the compound (C) is slow, the cohesive force of the pressure-sensitive adhesive itself may take longer to form, but the compound (C) can be used to improve the adhesion to the substrate as much as the slow curing speed, and as a result, the anchoring force of the pressure-sensitive adhesive layer is improved. has an effect on However, when only Compound (C) is used, there is a risk that the cohesive force of the pressure-sensitive adhesive itself may be excessively low. Therefore, it is preferable to use Compound (B) and Compound (C) in appropriate amounts.

Specifically, the pressure-sensitive adhesive composition may include aromatic isocyanate (B) as an isocyanate compound. The type of aromatic isocyanate compound is not particularly limited. For example, toluene diisocyanate (TDI), xylylene diisocyanate (XDI), bis(isocyanatoethyl)benzene, bis(isocyanatopropyl)benzene, bis(isocyanatobutyl)benzene, bis (Isocyanatomethyl)naphthalene, bis(isocyanatomethyl)diphenyl ether, phenylene diisocyanate, ethylphenylene diisocyanate, isopropylphenylene diisocyanate, dimethylphenylene diisocyanate, diethylphenylene diisocyanate, diisopropyl Phenylene diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate, biphenyl diisocyanate, toluidine diisocyanate, diphenylmethane diisocyanate (MDI), 3,3-dimethyldiphenylmethane-4,4-diisocyanate, bibenzyl- 4,4-diisocyanate, bis(isocyanatophenyl)ethylene, 3,3-dimethoxybiphenyl-4,4-diisocyanate, hexahydrobenzene diisocyanate, hexahydrodiphenylmethane-4,4-di Aromatic isocyanate compounds such as isocyanates may be used.

In addition, the pressure-sensitive adhesive composition includes an isocyanate compound (C) represented by Formula 1 below.

[Formula 1]

In Formula 1, R is a straight or branched chain alkyl or alkylene group having 1 to 10 carbon atoms, A1, A2 and A3 are each independently an alkylene group or an alkylidene group, m is an integer between 2 and 5, and , n is an integer between 2 and 10

In one example, R in Formula 1 may be an alkyl group having 1 to 4 carbon atoms, and may be, for example, a substituted or unsubstituted methyl, ethyl, propyl or butyl group according to the number of n.

In one example, in Chemical Formula 1, A1, A2, and A3 may each independently be an alkylene having 1 to 8 carbon atoms, and for example, may be methylene, ethylene, pentylene, hexylene, or octylene.

In one example, such a compound can be obtained by reacting, for example, a polyester-based polyol, an isocyanate, and a polyfunctional alcohol having two or more alcohol functional groups. The functional group of the polyfunctional alcohol undergoes a dehydration condensation reaction with polyester to form a three-dimensional structure. Preferably, the polyfunctional alcohol may have three or more reactive groups, and trimethylolpropane, trimethylolmethane, glycerin, or pentaerythritol may be exemplified as non-limiting examples of the polyfunctional alcohol.

Since the above compound has a relatively slow crosslinking rate, more crosslinking agents can be used to improve adhesion to the substrate, and can have elasticity (flexible characteristics) due to the unique structure as described above, resulting in improved anchoring power. is thought to contribute to

In one example, the pressure-sensitive adhesive composition may include 5 to 60 parts by weight of the isocyanate compound (C) represented by Formula 1 based on 100 parts by weight of the aromatic isocyanate (B). More specifically, the lower limit of the content of the isocyanate compound (C) is, for example, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, 10 parts by weight or more, 11 parts by weight or more, 12 parts by weight or more. It may be at least 13 parts by weight, at least 14 parts by weight or at least 15 parts by weight. And, the upper limit may be, for example, 55 parts by weight or less, 50 parts by weight or less, 45 parts by weight or less, or 40 parts by weight or less, and more specifically, 35 parts by weight or less, 34 parts by weight or less, 33 parts by weight or less. , 32 parts by weight or less, 31 parts by weight or less, 30 parts by weight or less, 29 parts by weight or less, 28 parts by weight or less, 27 parts by weight or less, 26 parts by weight or less, or 25 parts by weight or less. When the above content range is satisfied, anchoring power and durability of the desired adhesive may be secured.

In one example, the pressure-sensitive adhesive composition may further include a crosslinking agent other than isocyanate. The type of such crosslinking agent is not particularly limited, and a known crosslinking agent may be used. For example, an epoxy-based crosslinking agent, an aziridine-based crosslinking agent, and a metal chelate-based crosslinking agent may be used. Specifically, as the epoxy-based crosslinking agent, ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N', N'-tetraglycidyl ethylenediamine and glycerin diglycidyl At least one selected from the group consisting of cydyl ether may be used, and the aziridine-based crosslinking agent includes N,N-toluene-2,4-bis(1-aziridinecarboxamide), N,N'-diphenylmethane The group consisting of -4,4'-bis(1-aziridinecarboxamide), triethylene melamine, bisisoprotaloyl-1-(2-methylaziridine) and tri-1-aziridinylphosphine oxide At least one selected from may be used, and as the metal chelate-based crosslinking agent, a compound in which a multivalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium, and/or vanadium is coordinated with acetyl acetone or ethyl acetoacetate, etc. It can be used, but is not limited to those listed above.

In one example, the pressure-sensitive adhesive composition may include a crosslinking agent within a range of 0.1 to 5 parts by weight based on 100 parts by weight of the aromatic isocyanate (B). More specifically, the lower limit of the content of the crosslinking agent may be, for example, 0.2 parts by weight or more, 0.3 parts by weight or more, 0.4 parts by weight or more, or 0.5 parts by weight or more. And the upper limit may be, for example, 4 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less.

In one example, with regard to the amount of the total crosslinking agent used, the pressure-sensitive adhesive composition may include the crosslinking agent within a range of 0.001 part by weight to 10 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive polymer (A). For example, the pressure-sensitive adhesive composition may include crosslinking agents (B and C) within the range of 0.001 part by weight to 10 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive polymer (A). Alternatively, for example, the pressure-sensitive adhesive composition may include crosslinking agents (B, C, and D) within the range of 0.001 part by weight to 10 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive polymer (A). When the above range is satisfied, while maintaining the cohesive force of the pressure-sensitive adhesive appropriately, it is possible to prevent deterioration in durability reliability such as occurrence of peeling between layers or a lifting phenomenon.

The content ratio of the total crosslinking agent may be about 0.005 parts by weight or more, 0.01 parts by weight or more, 0.05 parts by weight or more, or 0.1 parts by weight or more in another example, and about 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less. It may be 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, 2 parts by weight or less, or 1.5 parts by weight or less.

In one example, the adhesive polymer may be an acrylic polymer. The term acrylic polymer has properties capable of forming an adhesive and may refer to a polymer containing an acrylic monomer unit as a main component. The term acrylic monomer may refer to a derivative of acrylic acid or methacrylic acid, such as acrylic acid, methacrylic acid or (meth)acrylic acid ester. In addition, being included as a main component in the above means that the ratio of the component is 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, It may mean a case of 80% or more, 85% or more, 90% or more, or 95% or more. In this case, the (weight) ratio of the components may be used in the same meaning as the content of the monomer used in forming the polymer. The upper limit of the ratio may be 100%. In addition, the unit contained in a polymer means the state in which a monomer forms the main chain and/or side chain of the said polymer through a polymerization reaction.

In one example, the adhesive polymer may include (1) an alkyl (meth)acrylate unit having an alkyl group having 4 or more carbon atoms, (2) an alkyl (meth)acrylate unit having an alkyl group having 3 or less carbon atoms, (3) an aromatic group-containing monomer units and (4) polar functional group-containing monomer units. Such a monomer composition enables the pressure-sensitive adhesive layer to exhibit excellent high-temperature durability while maintaining excellent properties such as reworkability, cutability, lifting and anti-foaming properties required for other pressure-sensitive adhesives.

In the above (1) unit, considering the cohesive force, glass transition temperature or adhesiveness of the pressure-sensitive adhesive, a unit of an alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms, for example, an alkyl group having 4 to 14 carbon atoms can be used Examples of the above alkyl (meth)acrylates include n-butyl (meth)acrylate, t-butyl (meth)acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate and tetra Decyl (meth)acrylate and the like may be exemplified, and one or two or more of the above may be applied. Generally, n-butyl acrylate or 2-ethylhexyl acrylate is used.

The ratio of the unit (1) in the polymer is not particularly limited, but may be in the range of about 50 to 70% by weight. The ratio may be about 85% by weight or less in another example.

As the unit (2), an alkyl (meth)acrylate unit having an alkyl group having 3 or less carbon atoms is used. Such a unit enables the adhesive to secure excellent durability and reliability at high temperatures. As the monomer capable of forming the unit, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate or isopropyl (meth)acrylate may be exemplified, and appropriate examples is methyl acrylate.

The unit (2) may be included in the polymer in an amount of about 15 to 45 parts by weight based on 100 parts by weight of the unit (1). Specifically, the lower limit of the ratio is, for example, 16 parts by weight or more, 17 parts by weight or more, 18 parts by weight or more, 19 parts by weight or more, 20 parts by weight or more, 21 parts by weight or more, 22 parts by weight or more, 23 parts by weight or more. It may be 24 parts by weight or more, 25 parts by weight or more, 26 parts by weight or more, 27 parts by weight or more, 28 parts by weight or more, 29 parts by weight or more, or 30 parts by weight or more. And the upper limit of the ratio, for example, 40 parts by weight or less, 39 parts by weight or less, 38 parts by weight or less, 37 parts by weight or less, 36 parts by weight or less, 35 parts by weight or less, 34 parts by weight or less, 33 parts by weight or less , 32 parts by weight or less, 31 parts by weight or less, or 30 parts by weight or less.

As the unit (3), a unit of an aromatic group-containing monomer, for example, a unit of a (meth)acrylate-based monomer having an aromatic ring is used.

The type of aromatic group-containing monomer capable of forming such a unit is not particularly limited, and for example, a monomer represented by the following formula (2) may be exemplified.

[Formula 2]

In Formula 2, R1 represents hydrogen or alkyl, A represents alkylene, n represents an integer in the range of 0 to 3, Q represents a single bond, -O-, -S- or alkylene, and P represents represents an aromatic ring.

In Formula 2, a single bond means a case in which atomic groups on both sides are directly bonded without intervening separate atoms.

In Formula 2, R1 may be, for example, hydrogen or alkyl having 1 to 4 carbon atoms, or may be hydrogen, methyl or ethyl.

In the definition of Formula 2, A may be an alkylene having 1 to 12 or 1 to 8 carbon atoms, for example, methylene, ethylene, hexylene or octylene.

In Formula 2, n may be, for example, a number within the range of 0 to 2, or 0 or 1.

In Formula 2, Q may be a single bond, -O- or -S-.

In Formula 2, P is a substituent derived from an aromatic compound, and may be, for example, a functional group derived from an aromatic ring having 6 to 20 carbon atoms, such as phenyl, biphenyl, naphthyl, or anthracenyl.

In Formula 2, the aromatic ring may be optionally substituted with one or more substituents, and specific examples of the substituents include halogen or alkyl, halogen or alkyl having 1 to 12 carbon atoms, chlorine, bromine, methyl, ethyl, propyl , butyl, nonyl or dodecyl, but is not limited thereto.

Specific examples of the compound of Formula 2 include phenoxy ethyl (meth)acrylate, benzyl (meth)acrylate, 2-phenylthio-1-ethyl (meth)acrylate, 6-(4,6-dibromo-2 -Isopropyl phenoxy)-1-hexyl (meth)acrylate, 6-(4,6-dibromo-2-sec-butyl phenoxy)-1-hexyl (meth)acrylate, 2,6-di Bromo-4-nonylphenyl (meth)acrylate, 2,6-dibromo-4-dodecyl phenyl (meth)acrylate, 2-(1-naphthyloxy)-1-ethyl (meth)acrylate , 2-(2-naphthyloxy)-1-ethyl (meth)acrylate, 6-(1-naphthyloxy)-1-hexyl (meth)acrylate, 6-(2-naphthyloxy)-1 -Hexyl (meth)acrylate, 8-(1-naphthyloxy)-1-octyl (meth)acrylate and 8-(2-naphthyloxy)-1-octyl (meth)acrylate or one or more of them. mixing, but is not limited thereto.

The unit (3) may be included in the polymer in an amount of about 10 to 40 parts by weight based on 100 parts by weight of the unit (1). Specifically, the lower limit of the ratio is, for example, 11 parts by weight or more, 12 parts by weight or more, 13 parts by weight or more, 14 parts by weight or more, 15 parts by weight or more, 16 parts by weight or more, 17 parts by weight or more, 18 parts by weight or more. Or more, it may be 19 parts by weight or more or 20 parts by weight or more. And, the upper limit of the ratio is, for example, 35 parts by weight or less, 34 parts by weight or less, 33 parts by weight or less, 32 parts by weight or less, 31 parts by weight or less, 30 parts by weight or less, 29 parts by weight or less, 28 parts by weight or less , 27 parts by weight or less, 26 parts by weight or less, or 25 parts by weight or less.

As the unit (4), a unit of a monomer having a hydroxy group or a carboxyl group as a polar functional group may be used. If necessary, these units may serve to impart cohesive force or the like through a reaction with a crosslinking agent or the like described later. As the monomer having a polar functional group in order to secure appropriate high-temperature reliability, etc., a hydroxyalkyl (meth)acrylate having a hydroxyalkyl group having 3 to 6 carbon atoms or a carboxyl group-containing monomer can be used.

As the hydroxyalkyl (meth)acrylate having a hydroxyalkyl group having 3 to 6 carbon atoms, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate or 6-hydroxy Hexyl (meth)acrylate and the like can be exemplified, and in one example, 4-hydroxybutyl (meth)acrylate can be used.

Examples of the carboxyl group-containing monomer include (meth)acrylic acid, 2-(meth)acryloyloxy acetic acid, 3-(meth)acryloyloxy propyl acid, 4-(meth)acryloyloxy butyric acid, and acrylic acid duplex. , itaconic acid, maleic acid, maleic anhydride, and the like can be exemplified, and acrylic acid can be generally applied.

However, when the pressure-sensitive adhesive layer is used adjacent to an electrode such as ITO (Indium Tin Oxide), if a large amount of carboxyl groups are included in the pressure-sensitive adhesive layer, corrosion of the electrode may be caused and the performance of the device may be adversely affected. Therefore, a component having a carboxyl group is not applied, or the upper limit of the application rate needs to be limited.

The unit (4) may be included in the polymer in an amount of about 0.5 to 5 parts by weight based on 100 parts by weight of the unit (1). In another example, the ratio may be about 1.0 parts by weight or more or 1.5 parts by weight or more, or about 5 parts by weight or less, 4.5 parts by weight or 4.0 parts by weight or less. In particular, when the (4) unit is a carboxyl group-containing monomer unit, the ratio is about 4.5 parts by weight or less, about 4 parts by weight or less, about 3.5 parts by weight or less, about 3 parts by weight or less, based on 100 parts by weight of the unit (1). parts by weight or less, about 2.5 parts by weight or less or 2 parts by weight or less.

By including the units of the above-mentioned monomers in the adhesive polymer and adjusting the ratio if necessary, stable durability at high temperatures is secured in the adhesive layer, other physical properties required for the adhesive layer are stably maintained, and adjacent to the electrode Even when disposed, corrosion of the corresponding electrode may not be caused.

If necessary, the adhesive polymer may further contain other known units in addition to the above-mentioned units.

The adhesive polymer can be prepared by a known polymerization method applying the above-mentioned monomers.

The pressure-sensitive adhesive composition may further include a conductive material (D). The conductive material may include an organic salt (a material containing an organic cation or a salt capable of providing it). That is, the conductive material used in the present application may be a material that does not contain a metal salt.

For example, when an optical laminate including a polarizer, a protective film, and an adhesive is used, the polyvinyl alcohol-based polarizer formed through underwater stretching has moisture. When the moisture moves toward the pressure-sensitive adhesive, the metal salt having high hydrophilicity tends toward the polarizer having relatively high moisture, and accordingly, a clouding phenomenon may occur at the interface between adjacent layers. This clouding phenomenon may occur equally when external moisture is dropped or dripped on any surface of the adhesive. However, since organic salts that do not contain metal salts are more hydrophobic than metal salts, they are less concentrated in water, and as a result, cloudiness can be suppressed.

In one example, the conductive material may be a compound containing an onium salt containing nitrogen, sulfur, or phosphorus as a cation component. If it is an onium salt, the type of cation is not particularly limited.

As the cation, N-ethyl-N,N-dimethyl-N-propylammonium, N,N,N-trimethyl-N-propylammonium, N-methyl-N,N,N-tributylammonium, N-ethyl- N,N,N-tributylammonium, N-methyl-N,N,N-trihexylammonium, N-ethyl-N,N,N-trihexylammonium, N-methyl-N,N,N-trioctyl quaternary ammonium compounds such as ammonium or N-ethyl-N,N,N-trioctylammonium; phosphoniums or derivatives thereof such as tetraalkyl phosphoniums; pyridinium or its derivatives; tetrahydropyridinium or its derivatives; dihydropyridinium or its derivatives; imidazolium or its derivatives; A compound containing a pyrroline skeleton or a derivative thereof; compounds or derivatives thereof containing a pyrrole skeleton; imidazolinium or derivatives thereof such as 1-ethyl-3-methylimidazolinium and the like; pyrazolium or its derivatives; trialkylsulfonium or its derivatives; pyrolidinium or derivatives thereof such as 1-methyl-1-propyl pyrrolidinium; or piperidinium or derivatives thereof such as 1-methyl-1-propyl piperidinium; etc. can be exemplified. At this time, the alkyl group included in the cation may be substituted with an alkoxy group, a hydroxy group, an alkynyl group, or an epoxy group.

In one example, the cation of the conductive material may be a compound represented by Formula 3 below.

[Formula 3]

In Formula 3, R ₁ to R ₄ each independently represent hydrogen, alkyl, alkoxy, alkenyl or alkynyl.

Alkyl or alkoxy in Formula 3 may be alkyl or alkoxy having 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. In addition, the alkyl or alkoxy may be straight-chain, branched-chain or cyclic alkyl or alkoxy, and may be optionally substituted with one or more substituents.

In Formula 3, alkenyl or alkynyl may be an alkenyl or alkynyl having 2 to 20 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms. In addition, the alkenyl or alkynyl may be a straight-chain, branched-chain or cyclic alkenyl or alkynyl, and may be optionally substituted with one or more substituents.

When alkyl, alkoxy, alkenyl or alkynyl in the definition of Formula 3 is substituted with one or more substituents, examples of substituents include hydroxy, alkyl, alkoxy, alkenyl, alkynyl, cyano, thiol, amino, aryl or heteroaryl; and the like, but are not limited thereto.

In one example, R ₁ to R ₄ in Formula 3 may each independently be an alkyl group, and may be, for example, a straight or branched chain having 1 to 12 carbon atoms.

In one example, R ₁ to R ₄ in Formula 3 each independently represent a straight or branched chain alkyl having 1 to 12 carbon atoms, but R ₁ to R ₄ may not correspond to alkyl having the same number of carbon atoms. In this case, within the scope of Formula 3, the case where R ₁ to R ₄ are all alkyl groups of the same number of carbon atoms is excluded. When all of R ₁ to R ₄ are alkyl having the same number of carbon atoms, the probability that the compound exists in a solid phase at room temperature may increase.

In another example, in Formula 3, R ₁ is an alkyl having 1 to 3 carbon atoms, and R ₂ to R ₄ may each independently be an alkyl having 4 to 20 carbon atoms, 4 to 15 carbon atoms, or 4 to 10 carbon atoms. When a conductive material containing cations as described above is used, it is advantageous to secure adhesion to a substrate as well as antistatic property.

Anions included in ionic compounds include PF ₆ ^- , AsF ^- , NO ₂ ^- , fluoride (F ^- ), chloride (Cl ^- ), bromide (Br ^- ), iodide (I ^- ), perchlorate (ClO ₄ ^- ), hydroxide (OH ^- ), carbonate (CO ₃ ^2- ), nitrate (NO ₃ ^- ), trifluoromethanesulfonate (CF ₃ SO ₃ ^- ), sulfonate (SO ₄ ^- ), Hexafluorophosphate (PF ₆ ^- ), methylbenzenesulfonate (CH ₃ (C ₆ H ₄ )SO ₃ ^- ), p-toluenesulfonate (CH ₃ C ₆ H ₄ SO ₃ ^- ), tetraborate (B ₄ O ₇ ^{2 -} ), carboxybenzenesulfonate (COOH(C ₆ H ₄ )SO ₃ ^- ), trifluoromethanesulfonate (CF ₃ SO ₂ ^- ), benzonate (C ₆ H ₅ COO ^- ), acetate ( CH ₃ COO ^- ), trifluoroacetate (CF ₃ COO ^- ), tetrafluoroborate (BF ₄ ^- ), tetrabenzylborate (B(C ₆ H ₅ ) ₄ ^- ) or trispentafluoroethyl trifluoro Phosphate (P(C ₂ F ₅ ) ₃ F ₃ ^- ) and the like may be exemplified.

In another example, an anion represented by Formula B below or bisfluorosulfonylimide may be used as the anion.

[Formula B]

[X(YO _m R _f ) _n ] ^-

In Formula B, X is a nitrogen atom or a carbon atom, Y is a carbon atom or a sulfur atom, R _f is a perfluoroalkyl group, m is 1 or 2, and n is 2 or 3.

In Formula B, when Y is carbon, m is 1, when Y is sulfur, m is 2, when X is nitrogen, n is 2, and when X is carbon, n can be 3.

The anion or bis(fluorosulfonyl)imide of Formula B exhibits high electronegativity due to a perfluoroalkyl group (R _f ) or a fluorine group, and also includes a unique resonance structure, forming a weak bond with a cation At the same time, it has hydrophobicity. Therefore, it is possible to impart high antistatic properties even with a small amount while exhibiting excellent compatibility with other components.

R _f in Formula B may be a perfluoroalkyl group having 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, in which case the perfluoroalkyl group is linear, branched or cyclic. can have a type structure. The anion of Formula B may be a sulfonylmethide-based, sulfonylimide-based, carbonylmethide-based, or carbonylimide-based anion, specifically, tristrifluoromethanesulfonylmethide anion, bistrifluoromethane Sulfonylimide anion, bisperfluorobutanesulfonylimide anion, bispentafluoroethanesulfonylimide anion, tristrifluoromethanecarbonylmethide anion, bisperfluorobutanecarbonylimide anion, or It may be one type or a mixture of two or more types, such as bispentafluoroethanecarbonylimide anion.

In one example, the composition may include 0.1 to 5 parts by weight of the organic salt-containing conductive material (D) based on 100 parts by weight of the acrylic polymer (A). Specifically, the organic salt-containing conductive material is 0.2 parts by weight or more, 0.3 parts by weight or more, 0.4 parts by weight or more, 0.5 parts by weight or more, 0.6 parts by weight or more, 0.7 parts by weight or more, 0.8 parts by weight or more, 0.9 parts by weight or more, 1.0 parts by weight or more, 1.1 parts by weight or more, 1.2 parts by weight or more, 1.3 parts by weight or more, 1.4 parts by weight or more, or 1.5 parts by weight or more. The upper limit of the content of the organic salt-containing conductive material is not particularly limited, but may be, for example, 4.5 parts by weight or less, 4.0 parts by weight or less, 3.5 parts by weight or less, 3.0 parts by weight or less, 2.5 parts by weight or less, or 2.0 parts by weight or less. .

The pressure-sensitive adhesive composition may further include other necessary known additives in addition to the above components. Examples of such additives include coupling agents such as silane coupling agents, tackifiers, and ultraviolet stabilizers; antioxidants; colorants; reinforcing agent; filler; antifoam; Surfactants; photopolymerizable compounds such as polyfunctional acrylates; And one or more selected from the group consisting of plasticizers may be exemplified, but is not limited thereto.

In another aspect of the present application, the present application relates to an optical stack. The optical laminate includes an optical element and an adhesive layer formed on one or both surfaces of the optical element. If necessary, a release film may be attached to the pressure-sensitive adhesive layer formed on one or both surfaces of the optical element.

The type of optical element included in the optical stack is not particularly limited, and may be various types of elements used in a display device. For example, the optical element may include a polarizing plate, a polarizer, a polarizer protective film, a retardation film, a viewing angle compensation film, or a luminance enhancing film. In this specification, the terms polarizer and polarizer refer to objects that are distinct from each other. A polarizer refers to a film, sheet, or device itself that exhibits a polarizing function, and a polarizer refers to an optical device including other elements together with the polarizer. As other elements that may be included in the optical element together with the polarizer, a polarizer protective film or a retardation layer may be exemplified, but is not limited thereto.

The optical element of the present application may include at least a so-called low moisture permeability optical film. In this application, the term low moisture permeability optical film is an optical film having low moisture permeability, for example, a water vapor transmission rate (WVTR) measured for 24 hours at a temperature of 37 ° C. and a relative humidity of 88.5 ± 0.5%. It means an optical film of about 100 g/m ² ·day or less. In one example, the moisture permeability is about 95 g/m ² day or less, 90 g/m ² day or less, 85 g/m ² day or less, 80 g/m ² day or less, 75 g/m ² day or less or less, 70 g/m ² day or less, 65 g/m ² day or less, 60 g/m ² day or less, 55 g/m ² day or less, 50 g/m 2 day or less, 45 g/m ² day or less m ² day or less, 40 g/m ² day or less, 35 g/m ² day or less, 30 g/m ² day or less, 25 g/m ² day or less, 20 g/m ² day or less , 15 g/m ² ·day or less, 10 g/m ² ·day or less, 8 g/m ² ·day or less, or 6 g/m ² ·day. The lower limit of the moisture permeability is not particularly limited, but is about 0.01 g/m ² day or more, 0.1 g/m ² day or more, 0.5 g/m ² day or more, 1 g/m ² day or more, 1.5 g /m ² day or more, 2 g/m ² day or more, 2.5 g/m ² day or more, 3 g/m ² day or more, 3.5 g/m ² day or more, 4 g/m ² day or more or more or 4.5 g/m ² ·day or more. The thickness of the optical film having the moisture permeability is not particularly limited. That is, an optical film having a thickness generally applied as an optical film and exhibiting the moisture permeability at that thickness may be applied to the optical element of the present application. In one example, the thickness of the optical film may be in the range of about 10 to 100 μm. The moisture permeability can be measured according to a method known in the art. As a representative standard for measuring moisture permeability, ASTM F1249 or ISO15506-3 is known, and the moisture permeability of the present application may be measured according to an appropriate method among the above.

Various types are known as the type of optical film with low moisture permeability as described above, for example, a polyester film such as a cycloolefin polymer (COP) film or an acrylic film or a poly(ethylene terephthalate) (PET) film. It can be. These films are usually hydrophilic, that is, hydrophobic films, than TAC films, which are widely used as protective films.

The low moisture permeability films as described above may be used as a protective film of a polarizer or as a material such as a retardation film.

In the case of using the low moisture permeability film and the organic salt-containing conductive material, it is possible to effectively suppress cloudiness. For example, when an optical laminate is used that sequentially includes a polarizer, a TAC-based protective film having high moisture permeability, and an adhesive, the polyvinyl alcohol-based polarizer formed through underwater stretching has moisture. The moisture easily migrates to the TAC-based protective film having high moisture permeability or penetrates the TAC-based protective film. At the same time, the metal salt-containing conductive material tends to the watery side. Accordingly, cloudiness occurs at interfaces between adjacent layers. However, the low moisture permeability film can suppress the movement of moisture, and as described above, since the organic salt-containing conductive material has a hydrophobicity compared to the metal salt-containing conductive material, cloudiness can be suppressed.

In one example, the low moisture permeability film used in the device of the present application may be an acrylic film. In the case of a commercially available TAC film, the water vapor transmission rate (WVTR) measured as described above is about 100 g/m ² ·day or more, and the water vapor transmission rate of the acrylic film is about 5 to 35 g/m ² ·day. As described above, the acrylic film has poorer anchoring power than other films, but in the present application using the above-described adhesive, the durability and anchoring power of the optical laminate can be improved even when the acrylic film is used.

When such a low moisture permeability film forms an optical laminate together with an adhesive layer, foaming is likely to occur in the adhesive due to the low moisture permeability and hydrophobicity of the film. is triggered Considering these points, it is necessary to improve the adhesion between the pressure-sensitive adhesive and the substrate, that is, keying force.

The pressure-sensitive adhesive having the above structure according to the present application may suppress foaming while stably maintaining durability even when the optical film having low moisture permeability as described above is applied. Specifically, since the pressure-sensitive adhesive is formed from a cross-linking agent-containing composition containing a cross-linking agent having a specific structure in a specific amount, it can react sensitively to deformation of adjacent components (eg, a low moisture permeability film or polarizer). Therefore, compared to a conventional adhesive optical laminate including a low moisture permeability film, lifting, peeling, or foaming between adjacent layers is suppressed, and as a result, the anti-light leakage properties of the polarizing plate can be further improved.

A typical example of an optical element including the film having low moisture permeability as described above is a polarizing plate. Such a polarizing plate may include the low moisture permeability optical film together with a polarizer exhibiting a polarizing function, and the low moisture permeability optical film may be included in the polarizing plate as a protective film or a retardation film for the polarizer. Accordingly, in one example according to the present application, the polarizing plate may include a polarizer and the low moisture permeability optical film formed on one surface of the polarizer.

In the structure of the polarizing plate, the low moisture permeability optical film may be formed on only one surface of the polarizer, or the low moisture permeability optical film may be formed on both sides of the polarizer. When formed on only one surface, an optical film may not exist, another optical functional layer may exist, or an optical film having high moisture permeability may exist on the other surface. When the low moisture permeability optical film is formed only on one side of the polarizer, the low moisture permeability optical film described below may be located closer to the pressure-sensitive adhesive layer described later than the polarizer. For example, the optical laminate may sequentially include a polarizer, a low moisture permeability film, and an adhesive layer.

Polarizers that can be included in the optical laminate of the present application are basically not particularly limited. For example, as a polarizer, a polyvinyl alcohol polarizer can be used. The term polyvinyl alcohol polarizer may mean, for example, a polyvinyl alcohol (hereinafter referred to as PVA)-based resin film including an anisotropic absorbent material such as iodine or a dichroic dye. Such a film can be produced by including an anisotropic absorbent material in a polyvinyl alcohol-based resin film and orienting it by stretching or the like. Examples of the polyvinyl alcohol-based resin include polyvinyl alcohol, polyvinyl formal, polyvinyl acetal, or a saponified product of ethylene-vinyl acetate copolymer. The degree of polymerization of the polyvinyl alcohol-based resin may be about 100 to 5,000 or about 1,400 to 4,000, but is not limited thereto.

Such a polyvinyl alcohol polarizer can be manufactured, for example, by at least performing a dyeing process, a crosslinking process, and an stretching process on a PVA-based film. In the dyeing process, the crosslinking process, and the stretching process, each treatment bath of a dyeing bath, a crosslinking bath, and a stretching bath is used, and a treatment liquid according to each process may be used for each treatment bath.

In the dyeing process, the anisotropic absorbent material may be adsorbed and/or oriented on the PVA-based film. This dyeing process may be performed together with the stretching process. Dyeing may be performed by immersing the film in a solution containing an anisotropic absorbent material, for example, an iodine solution. As the iodine solution, for example, an aqueous solution in which iodine ions are contained by iodine and an iodide compound as a solubilizing agent may be used. Examples of the iodide compound include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, or titanium iodide. The concentration of iodine and/or iodide ions in the iodine solution can be adjusted in consideration of the optical properties of a desired polarizer, and such an adjustment method is known. In the dyeing process, the temperature of the iodine solution is usually 20 ° C to 50 ° C, 25 ° C to 40 ° C, and the immersion time is usually 10 seconds to 300 seconds or 20 seconds to 240 seconds, but is not limited thereto.

A crosslinking process performed in the manufacturing process of the polarizer may be performed using, for example, a crosslinking agent such as a boron compound. The order of the crosslinking process is not particularly limited, and may be performed together with, or separately from, the dyeing and/or stretching process, for example. A crosslinking process may be performed several times. As the boron compound, boric acid or borax may be used. The boron compound can be generally used in the form of an aqueous solution or a mixed solution of water and an organic solvent, and boric acid aqueous solution is usually used. The concentration of boric acid in the aqueous solution of boric acid may be selected within an appropriate range in consideration of the degree of crosslinking and the resulting heat resistance. An iodide compound, such as potassium iodide, can be contained also in boric acid aqueous solution etc.

The crosslinking process may be performed by immersing the PVA-based film in an aqueous solution of boric acid or the like. In this process, the treatment temperature is usually in the range of 25 ° C. or higher, 30 ° C. to 85 ° C., or 30 ° C. to 60 ° C., and the treatment time is usually 5 seconds to 800 seconds or 8 seconds to 500 seconds.

The stretching step is generally performed by uniaxial stretching. Such stretching may be performed together with the above dyeing and/or crosslinking process. The stretching method is not particularly limited, and, for example, a wet stretching method may be applied. In such a wet stretching method, it is common to carry out stretching after dyeing, for example, but stretching may be carried out together with crosslinking, and may be carried out multiple times or in multiple stages.

An iodide compound such as potassium iodide may be contained in the treatment solution applied to the wet stretching method, and the light blocking rate may be controlled by adjusting the ratio in this process. In the stretching, the treatment temperature is usually in the range of 25 ° C. or more, 30 ° C. to 85 ° C., or 50 ° C. to 70 ° C., and the treatment time is usually 10 seconds to 800 seconds or 30 seconds to 500 seconds, but is not limited thereto. .

In the stretching process, the total stretching ratio may be adjusted in consideration of orientation characteristics, etc., and the total stretching ratio may be 3 to 10 times, 4 to 8 times, or 5 to 7 times based on the original length of the PVA-based film. , but is not limited thereto. In the above, the total draw ratio may mean the cumulative draw ratio including the draw in each step, in the case of accompanying drawing in a swelling step other than the drawing step. This total stretching ratio may be adjusted to an appropriate range in consideration of orientation, processability of the polarizer, or the possibility of stretching and cutting.

In the manufacturing process of the polarizer, a swelling process may be performed before performing the above process in addition to the above dyeing, crosslinking and stretching. By swelling, stains and antiblocking agents on the surface of the PVA-based film can be washed, and also there is an effect of reducing non-uniformity such as uneven coloring.

Water, distilled water or pure water may be used in the swelling process. The main component of the treatment liquid is water, and if necessary, an iodide compound such as potassium iodide or an additive such as a surfactant, or a small amount of alcohol or the like may be included. Even in this process, the above-described light blocking rate may be controlled by adjusting process variables.

The treatment temperature in the swelling process is usually about 20 ° C to 45 ° C or 20 ° C to 40 ° C, but is not limited thereto. Since swelling deviations can cause dyeing deviations, the process parameters can be adjusted so that the occurrence of these swelling deviations is suppressed as much as possible.

If necessary, appropriate stretching may be performed even in the swelling process. The stretching ratio may be about 6.5 times or less, 1.2 to 6.5 times, 2 to 4 times, or 2 to 3 times based on the original length of the PVA-based film. Stretching in the swelling process can be controlled to keep the stretching in the stretching process performed after the swelling process small, and can be controlled so that the stretching breakage of the film does not occur.

During the manufacturing process of the polarizer, metal ion treatment may be performed. Such a treatment is performed, for example, by immersing the PVA-based film in an aqueous solution containing a metal salt. Through this, it is possible to contain metal ions in the planar. In this process, it is possible to adjust the color tone of the PVA-based polarizer by adjusting the type or ratio of metal ions. As the metal ion that can be applied, metal ions of transition metals such as cobalt, nickel, zinc, chromium, aluminum, copper, manganese, or iron may be exemplified. have.

In the process of manufacturing the polarizer, a cleaning process may be performed after dyeing, crosslinking, and stretching. This cleaning process may be performed with an iodine compound solution such as potassium iodide. In this process, the above-described light blocking rate may be controlled through the concentration of the iodide compound in the solution or the treatment time of the cleaning process. Therefore, the concentration of the iodide compound and the treatment time with the solution may be adjusted in consideration of the light blocking rate. However, the cleaning process may be performed using water.

The washing with water and the washing with an iodine compound solution may be combined, and a solution containing liquid alcohol such as methanol, ethanol, isopropyl alcohol, butanol or propanol may also be used.

After passing through these processes, a drying process may be performed to manufacture a polarizer. In the drying process, for example, it may be performed at an appropriate temperature for an appropriate time in consideration of the moisture content required for the polarizer, and these conditions are not particularly limited.

In one example, a polyvinyl alcohol polarizer including a potassium component such as potassium ion and a zinc component such as zinc ion may be used as the polarizer in order to secure durability of the optical laminate, particularly high-temperature reliability. When a polarizer containing these components is used, it is possible to provide an optical laminate stably maintaining durability even under high-temperature conditions, particularly ultra-high-temperature conditions of 100° C. or higher.

The ratio of the potassium and zinc components may be further adjusted. For example, the ratio (K/Zn) of the potassium component (K) and the zinc component (Zn) included in the polyvinyl alcohol polarizer may be within the range of 0.2 to 6 in one example. In other examples, the ratio (K/Zn) may be about 0.4 or more, 0.6 or more, 0.8 or more, 1 or more, 1.5 or more, 2 or more, or 2.5 or more, and may be 5.5 or less, about 5 or less, about 4.5 or less, or about 4 or less. have.

In addition, the ratio of the potassium component included in the polyvinyl alcohol polarizer may be about 0.1 to 2% by weight. The ratio of the potassium component may be about 0.15% by weight or more, about 0.2% by weight or more, about 0.25% by weight or more, about 0.3% by weight or more, about 0.35% by weight or more, 0.4% by weight or more, or about 0.45% by weight or more in another example. And, about 1.95% by weight or less, about 1.9% by weight or less, about 1.85% by weight or less, about 1.8% by weight or less, about 1.75% by weight or less, about 1.7% by weight or less, about 1.65% by weight or less, about 1.6% by weight or less, About 1.55% or less, about 1.5% or less, about 1.45% or less, about 1.4% or less, about 1.35% or less, about 1.3% or less, about 1.25% or less, about 1.2% or less, about 1.15 up to about 1.1%, up to about 1.05%, up to about 1%, up to about 0.95%, up to about 0.9%, or up to about 0.85% by weight.

In one example, the ratio of the potassium component and the zinc component may be included to satisfy Equation A below.

[Formula A]

0.70 to 0.95 = 1/(1+Q×d/R)

In Equation A, Q is the ratio (K/Zn) of the molar mass of the potassium component (K, 39.098 g/mol) and the molar mass of the zinc component (Zn, 65.39 g/mol) contained in the polyvinyl alcohol polarizer, and d Is the thickness of the polyvinyl alcohol polarizer before stretching (㎛) / 60㎛, R is the weight ratio (K, unit: weight%) of the potassium component contained in the polyvinyl alcohol polarizer and the weight ratio of the zinc component (Zn, unit: weight %) is the ratio (K/Zn).

By including potassium and zinc components in the polarizer in the form described above, it may be possible to provide a polarizer having excellent reliability at high temperatures.

The thickness of the polarizer as described above is not particularly limited, and may be formed to an appropriate thickness depending on the purpose. Typically, the thickness of the polarizer may be in the range of 5 μm to 80 μm, but is not limited thereto.

The optical laminate may include an adhesive layer formed on one or both surfaces of the optical element. This pressure-sensitive adhesive layer contains an adhesive polymer. The pressure-sensitive adhesive layer may include the pressure-sensitive adhesive polymer as a main component. That is, the ratio of the adhesive polymer to the total weight of the pressure-sensitive adhesive layer is 55% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, 75% by weight or more, 80% by weight or more, 85% by weight or more. Or it may be 90% by weight or more. The upper limit of the ratio is not particularly limited, and may be, for example, 100% by weight or less, about 98% by weight or less, or 95% by weight or less. As described above, the pressure-sensitive adhesive polymer may be included in the pressure-sensitive adhesive layer in a crosslinked state by a crosslinking agent.

The properties of the pressure-sensitive adhesive layer may be controlled to secure excellent durability under high temperature conditions, particularly at ultra-high temperatures of 100° C. or higher, and to suppress or prevent foaming even when applied with an optical film having low moisture permeability.

This application also relates to a display device including the optical laminate as described above. The device may include, for example, a display panel to which the optical laminate is attached via the above-mentioned pressure-sensitive adhesive layer. In the above, the type of display panel is not particularly limited, and may be, for example, a known LCD panel or OLED panel. In addition, the position where the optical laminate is attached to the panel may also follow a known method.

According to the present application, it is possible to provide an optical laminate having stable durability even at a high temperature, particularly at a very high temperature of about 100° C. or higher, and having excellent anchoring power, thereby suppressing foaming. In addition, according to the present application, even when disposed adjacent to an electrode, an optical laminate that does not cause corrosion of the electrode may be provided.

Although the present application is specifically described through the following examples, the scope of the present application is not limited by the following examples.

< Example One: Peel force , high temperature durability, anchoring power and ITO Corrosiveness Assessment>

Evaluation items and evaluation method

One. Peel force ( gf /25mm)

Each of the adhesive polarizers prepared in Examples and Comparative Examples was cut to have a horizontal length of 25 mm and a vertical length of 200 mm to prepare specimens, and were attached to a glass plate through an adhesive layer of the specimen. At 1 hour after specimen attachment, the peel force was measured while peeling the adhesive polarizer at a peel angle of 90 ° and a peel speed of 300 mm/min.

2. High temperature durability (high temperature reliability)

Each of the adhesive polarizers prepared in Examples and Comparative Examples was cut to have a horizontal length of about 140 mm and a vertical length of about 90 mm to prepare a specimen, and then 5 kg/cm ² on a glass substrate. Attached with pressure. The attachment was performed in a clean room so that no bubbles or foreign substances were generated. Subsequently, the prepared sample was maintained in an autoclave for 15 minutes at 50°C and 5 kg/cm ² .

After maintaining the sample at a temperature of about 100° C. for about 500 hours, durability was evaluated according to the following criteria.

<Evaluation Criteria>

O: Bubbles and peeling are not observed

△: Bubbles are generated, and peeling is partially observed

X: Air bubbles and peeling were severely observed

3. anchoring power (missing) evaluation

Keying force is a physical quantity that reflects the adhesion between the pressure-sensitive adhesive layer and the base material. Each of the pressure-sensitive adhesive layers prepared in Examples and Comparative Examples and attached to the release film was laminated on a polarizing plate, aged for 7 days under constant temperature and humidity conditions (23 ° C. 50% relative humidity), and anchoring power for the sample. was evaluated. Specifically, after removing the release film of the pressure-sensitive adhesive layer from the sample, an Americal Tapel adhesive tape having a width of about 50 mm was attached to the pressure-sensitive adhesive layer of the sample, and when the adhesive tape was separated from the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer adhered to the polarizing plate. The remaining amount was visually confirmed and evaluated. The weaker the keying force, the more the pressure-sensitive adhesive layer separates from the polarizing plate, which is an adherend, and is transferred to the pressure-sensitive adhesive tape during evaluation, and accordingly, a lot of vacancy of the pressure-sensitive adhesive is confirmed in the pressure-sensitive adhesive layer positioned on the polarizing plate. As described above, when there is a lot of vacancy, it can be seen that the anchoring force is weak.

<Evaluation Criteria>

◎: No empty space observed in the pressure-sensitive adhesive layer on the polarizing plate

○: The area of empty space observed in the pressure-sensitive adhesive layer located on the polarizing plate is 10% or less of the total area of the pressure-sensitive adhesive layer

△: The area of the empty space observed in the pressure-sensitive adhesive layer located on the polarizing plate is within the range of 10 to 30% of the total area of the pressure-sensitive adhesive layer

X: The area of the empty space observed in the pressure-sensitive adhesive layer located on the polarizing plate is 30% or more of the total area of the pressure-sensitive adhesive layer

4. ITO corrosion

Each of the pressure-sensitive adhesive compositions prepared in Examples and Comparative Examples was laminated on a 40 μm-thick TAC (Triacetyl cellulose) film, and the pressure-sensitive adhesive layer was aged for 7 days under constant temperature and humidity conditions (23° C. 50% relative humidity). was manufactured. A commercially available ITO (Indium Tin Oxide) film is cut to a horizontal length of about 50 mm and a vertical length of about 30 mm to prepare a specimen, and on top of that, each end of the horizontal direction has a width of about 10 mm. silver paste was applied. Subsequently, the pressure-sensitive adhesive layer was cut to have a horizontal length of about 40 mm and a vertical length of about 30 mm, and was attached to an end portion of the silver paste at an interval of about 5 mm to prepare a specimen. After preserving the prepared ITO film for 250 hours under high temperature and high humidity conditions (85° C. 85% relative humidity), the rate of change in resistance compared to before initial input was evaluated with a wire resistance meter (Hioki 3244-60 card hitester).

<Evaluation Criteria>

◎: resistance change rate is less than 40%

○: Resistance change rate is within the range of 40 to 100%

△: resistance change rate within the range of 100 to 180%

X: resistance change rate is 180% or more

Example and comparative example

Example One

(1) Preparation of adhesive polymer

n-butyl acrylate (n-BA), benzyl acrylate (BzA), methyl acrylate (MA) and acrylic acid (AA) were mixed in a 1 L reactor with a reflux of nitrogen gas and a cooling device for easy temperature control. It was added at a weight ratio of 64:15:20:1 (n-BA:BzA:MA:AA), and 100 parts by weight of ethyl acetate (EAc) was added as a solvent. Subsequently, nitrogen gas was purged for 1 hour to remove oxygen, and then 0.03 parts by weight of azobisisobutyronitrile (AIBN) diluted in ethyl acetate at a concentration of 50% by weight was added as a reaction initiator and reacted for 8 hours to obtain a weight average A copolymer (A) having a molecular weight (Mw) of about 1.65 million was prepared.

(2) Preparation of pressure-sensitive adhesive composition

Based on 100 parts by weight of the solid content of the copolymer (A) prepared in (1) above, 0.8 parts by weight of toluene diisocyanate (TDI) (trade name T-706BB), derived from hexamethylene isocyanate (HDI) represented by the following formula 1-1 Di-n-butyltin dilaurate (di-n- A butyltin dilaurate)-based catalyst (C-700, Hannong Chemical) was blended at about 0.001 part by weight based on 100 parts by weight of the solid content of the copolymer (A), and additionally, 1.5 parts by weight of a conductive additive (FC4400A diluted to 70%) and a crosslinking delay After blending acetyl acetone as an agent in an amount of about 1 part by weight based on 100 parts by weight of the solid content of the copolymer (A), diluted to an appropriate concentration and uniformly mixed, the coating solution is coated on a release paper and dried to a thickness of 22 μm. A uniform pressure-sensitive adhesive layer of was prepared.

[Formula 1-1]

(2) Manufacture of polarizer

A poly(vinyl alcohol) film (Nippon Synthesis, M2004) having a thickness of about 30 μm was immersed in a dye solution at 30 ° C. containing 0.05% by weight of iodine and 1.5% by weight of potassium iodide for 60 seconds. It was dyed and treated. Subsequently, the dyed PVA film was immersed in a crosslinking solution containing 0.5% by weight of boron and 3.0% by weight of potassium iodide at 30° C. for 60 seconds to perform crosslinking treatment. Thereafter, the crosslinked PVA film was stretched at a stretch ratio of 5.5 times using an inter-roll stretching method. The stretched PVA film was washed by being immersed in ion-exchanged water at 30°C for 20 seconds, and then immersed in a solution containing 1.5% by weight of zinc nitrate and 4.0% by weight of potassium iodide at 30°C for 10 seconds. Thereafter, the PVA film was dried at a temperature of 80° C. for 200 seconds to prepare a polarizer. The potassium content in the prepared polarizer was about 0.47% by weight, and the zinc content was about 0.17% by weight. Subsequently, on one side of the polarizer, the water vapor transmission rate (WVTR) measured for 24 hours at 37 ° C. A polarizing plate was prepared by attaching an acrylic film of about 15 g/m ² ·day with an adhesive, and attaching a TAC (triacetyl cellulose) film, a known polarizer protective film, to the other side with an adhesive.

(4) optics of the laminate (adhesive polarizer) Produce

The prepared pressure-sensitive adhesive layer was adhered to the acrylic film surface of the polarizing plate to prepare an adhesive polarizing plate (optical laminate).

comparative example 1 to 9

As shown in Table 2 below, a pressure-sensitive adhesive composition, a polarizing plate, and a pressure-sensitive adhesive polarizing plate were prepared in the same manner as in Example 1, except that the type and content of the crosslinking agent were different. For reference, Table 1 compares the NCO content contained in the HDI-based crosslinking agent used in each Example and Comparative Example.

[Table 1]

[Table 2]

[Table 3]

< Example 2: cloudy shape evaluation>

Example and comparative example

Example 2

An adhesive polarizing plate was prepared in the same manner as in Example 1, and a release film was attached to the surface of the adhesive exposed to the outside.

Comparative Example 9

An adhesive polarizer was prepared in the same manner, except that LiTFSi (Lithium bis(trifluoromethanesulfonyl)imide) was used instead of FC-4400 in the adhesive composition.

One side of the release film was peeled off from the adhesive polarizer prepared in Example 2 and Comparative Example 9, and distilled water droplets were dropped on the pressure-sensitive adhesive layer exposed after the release film was peeled off, respectively. In addition, it was visually evaluated whether or not a cloudiness phenomenon in which the dropped distilled water droplets become cloudy was generated.

As a result of visual evaluation, Example 2 did not cause cloudiness, whereas the surface of the adhesive polarizer of Comparative Example 9 showed cloudiness.

Claims (16)

Acrylic polymer (A) having a polar functional group;
aromatic isocyanates (B);
An isocyanate compound (C) represented by the following formula (1); and
Pressure-sensitive adhesive composition comprising organic salt-containing conductive material (D):
[Formula 1]

However, in Formula 1, R is an alkyl group having 1 to 10 carbon atoms, A1, A2 and A3 are each independently an alkylene group or an alkylidene group, m is an integer between 2 and 5, and n is 2 to 10 is an integer between The method of claim 1, wherein the polymer (A) is an alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms, an alkyl (meth)acrylate having an alkyl group having 3 or less carbon atoms, an aromatic group-containing monomer, and a polar functional group-containing monomer. A pressure-sensitive adhesive composition comprising a. The pressure-sensitive adhesive composition according to claim 1, comprising 5 to 60 parts by weight of the isocyanate compound (C) represented by Formula 1 based on 100 parts by weight of the aromatic isocyanate (B). The pressure-sensitive adhesive composition according to claim 1, which comprises 0.001 part by weight to 10 parts by weight of the aromatic isocyanate (B) and the isocyanate compound (C) represented by Formula 1 based on 100 parts by weight of the polymer (A). The pressure-sensitive adhesive composition according to claim 1, further comprising an epoxy-based crosslinking agent, an aziridine-based crosslinking agent, or a metal chelate-based crosslinking agent. The pressure-sensitive adhesive composition according to claim 2, comprising 15 to 45 parts by weight of an alkyl (meth)acrylate having an alkyl group having 3 or less carbon atoms based on 100 parts by weight of the alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms. . The pressure-sensitive adhesive composition according to claim 2, wherein the aromatic group-containing monomer is represented by Formula 2 below:
[Formula 2]

In Formula 2, R1 represents hydrogen or alkyl, A represents alkylene, n represents an integer in the range of 0 to 3, Q represents a single bond, -O-, -S- or alkylene, and P represents represents an aromatic ring. The pressure-sensitive adhesive composition according to claim 2, wherein the aromatic group-containing monomer is contained in an amount of 10 to 40 parts by weight based on 100 parts by weight of the alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms. The pressure-sensitive adhesive composition according to claim 2, wherein the monomer having a polar functional group is a hydroxyalkyl (meth)acrylate having a hydroxyalkyl group having 3 to 6 carbon atoms or a carboxyl group-containing monomer. The pressure-sensitive adhesive composition according to claim 2, comprising 0.5 to 5 parts by weight of the monomer having the polar functional group based on 100 parts by weight of the alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms. The pressure-sensitive adhesive composition according to claim 1, comprising 0.1 to 5 parts by weight of the organic salt-containing conductive material (D) based on 100 parts by weight of the acrylic polymer (A). An optical element comprising an optical film having a moisture permeability of 100 g/m ² ·day or less measured after storage at 37° C. and 88.5±0.5% relative humidity for 24 hours; and
An optical laminate having a pressure-sensitive adhesive layer formed on one surface of the optical element and containing a cured product of the pressure-sensitive adhesive composition according to claim 1. The optical laminate according to claim 12, wherein the optical film having a water vapor transmission rate of 100 g/m ² ·day or less is an acrylic film. 13. The optical stack according to claim 12, wherein the optical element is a polarizing plate. 15. The method of claim 14, wherein the polarizing plate comprises: a polarizer; and an optical film formed on one side of the polarizer and having the moisture permeability. An optical laminate according to any one of claims 12 to 15; and a display panel attached to the optical laminate through the pressure-sensitive adhesive layer of the laminate.