KR102097810B1 - Pressure-sensitive adhesive composition - Google Patents

Abstract

상기 화학식 1에서, R1은 수소 또는 탄소수 1 내지 12의 알킬기이고, R2는 탄소수 1 내지 12의 알킬렌기이되, 상기 알킬기 또는 알킬렌기는 아릴기, 히드록시기, 우레탄기, 케톤기, 또는 에스터기로 치환될 수 있고, R3 내지 R5 중 적어도 하나는 탄소수 1 내지 9의 알콕시기, 아릴옥시기 또는 할로겐이다.The pressure-sensitive adhesive composition according to the present invention, (meth) acrylic acid ester monomer (A) 85 parts by weight to 99.9 parts by weight, a copolymerizable monomer having a crosslinkable functional group (B) 0.1 parts by weight to 15 parts by weight, and represented by the following formula (1) It may include a copolymer having a polymerization unit derived from the compound (C) to be:
[Formula 1]

In Formula 1, R1 is hydrogen or an alkyl group having 1 to 12 carbon atoms, and R2 is an alkylene group having 1 to 12 carbon atoms, wherein the alkyl group or alkylene group is substituted with an aryl group, hydroxy group, urethane group, ketone group, or ester group. Can be, at least one of R3 to R5 is an alkoxy group having 1 to 9 carbon atoms, an aryloxy group, or halogen.

Description

Adhesive composition {PRESSURE-SENSITIVE ADHESIVE COMPOSITION}

The present application relates to an adhesive composition, an optical laminate, a polarizing plate and a display device.

Display devices include various optical films. For example, a liquid crystal display device (hereinafter referred to as "LCD device") generally includes a liquid crystal panel and an optical film injected between two transparent substrates. Examples of the optical film include a polarizing film, a retardation film, or a brightness enhancing film, and an adhesive for the optical film is required to laminate these optical films. In addition, an adhesive can also be used when the optical film is attached to an adherend such as a liquid crystal panel.

 When considering the use environment of the pressure-sensitive adhesive, the pressure-sensitive adhesive needs to maintain a high adhesion even under heat and / or moisture heat conditions. To this end, a coupling agent such as a silane coupling agent has been used, but a silane coupling agent having high volatility at high temperature is easily lost during the drying process of the product, thereby deteriorating the adhesive strength of the adhesive, bubbles at the adhesive interface, Or the peeling problem of the adhesive appeared. In addition, when a silane-based coupling agent is used, a curing agent may be additionally added. Such a curing agent includes a decrease in durability of the pressure-sensitive adhesive due to over-curing, an increase in durability over time due to further curing of the residual curing agent after drying, and an adhesive composition. It causes problems such as a decrease in storage stability of the coating solution. In addition, when a curing agent and a silane-based coupling agent are used together, some structures included in the silane-based coupling agent may cause chelating of the tin-based curing catalyst, thereby slowing the curing rate.

The object of the present application is to provide an adhesive composition having excellent adhesion even under heat and / or moisture heat conditions.

Another object of the present application is to provide a pressure-sensitive adhesive composition with a change in durability over time.

Another object of the present application is to provide an optical laminate, a polarizing plate, and / or a display device including an adhesive layer having excellent adhesion and suppressing change over time.

The pressure-sensitive adhesive composition according to an embodiment of the present application, (meth) acrylic acid ester monomer (A) 85 parts by weight to 99.9 parts by weight, a copolymerizable monomer having a crosslinkable functional group (B) 0.1 parts by weight to 15 parts by weight, and It may include a copolymer having a polymerization unit derived from the compound (C) represented by the formula (1).

 [Formula 1]

In Formula 1, R1 is hydrogen or an alkyl group having 1 to 12 carbon atoms, and R2 is an alkylene group having 1 to 12 carbon atoms, wherein the alkyl group or alkylene group is substituted with an aryl group, hydroxy group, urethane group, ketone group, or ester group. It may be, and at least one of R3 to R5 may be an alkoxy group having 1 to 9 carbon atoms, an aryloxy group, or halogen.

In one example, the compound (C) may be included in the range of 0.01 parts by weight to 2 parts by weight, relative to 100 parts by weight, including (meth) acrylic ester monomer (A) and a copolymerizable monomer (B) having a crosslinkable functional group. have.

In another example, the crosslinkable functional group may be a hydroxy group.

In another example, the pressure-sensitive adhesive composition may include a crosslinking agent having two or more functional groups capable of reacting with a crosslinkable functional group in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the copolymer.

In another example, the pressure-sensitive adhesive composition may include 0.1 parts by weight to 10 parts by weight of an antistatic agent relative to 100 parts by weight of the copolymer.

In another example, the pressure-sensitive adhesive may have a gel fraction of 90% by weight or less after implementing a cross-linked structure.

The present application provides a pressure-sensitive adhesive composition that maintains adhesion even under heat- and / or heat-resistance conditions and has excellent light leakage prevention properties and reworkability. In addition, since the pressure-sensitive adhesive composition of the present application does not contain a silane-based coupling agent, it is possible to solve a problem of a decrease in adhesion due to use of a silane-based coupling agent or a bubble generation problem, and a decrease in durability of the pressure-sensitive adhesive due to use of an excessive amount of curing agent.

This application relates to an adhesive composition. In an example related to the present application, the pressure-sensitive adhesive composition may include a copolymer prepared by radical polymerization. In one example, the copolymer may mean a random copolymer in which monomers constituting the copolymer are randomly bound in the copolymer.

In one example, the copolymer contained in the pressure-sensitive adhesive composition of the present application includes (meth) acrylic acid ester monomer (A), a copolymerizable monomer having a crosslinkable functional group (B), and a compound represented by Formula 1 (C) It may have a polymerization unit derived from.

 [Formula 1]

In Formula 1, R1 is hydrogen or an alkyl group having 1 to 12 carbon atoms, and R2 is an alkylene group having 1 to 12 carbon atoms, wherein the alkyl group or alkylene group is substituted with an aryl group, hydroxy group, urethane group, ketone group, or ester group. It may be, and at least one of R3 to R5 may be an alkoxy group having 1 to 9 carbon atoms, an aryloxy group, or halogen.

In one example, the copolymer, (meth) acrylic acid ester monomer (A), a copolymerizable monomer having a crosslinkable functional group (B), and a monomer mixture comprising a compound (C) represented by the formula (1) Can be manufactured. Specifically, the copolymer (meth) acrylic acid ester monomer (A) 85 parts by weight to 99.9 parts by weight, a copolymerizable monomer having a crosslinkable functional group (B) 0.1 parts by weight to 15 parts by weight, and represented by the formula (1) Compound (C) may include a polymerization unit derived from 0.01 to 2 parts by weight. At this time, when the content of the compound (C) is 100 parts by weight by adding the content of the (meth) acrylic acid ester monomer (A) and the content of the copolymerizable monomer (B) having the crosslinkable functional group, the content based on this it means.

In the present specification, "the polymerization unit derived from a monomer is contained in the copolymer" may mean that the monomer undergoes a polymerization reaction to form a skeleton of the copolymer, for example, a main chain or a side chain. In addition, in this specification, "part by weight" may mean a weight ratio between each component. For example, (meth) acrylic acid ester monomer (A) 85 parts by weight to 99.9 parts by weight, a copolymerizable monomer having a crosslinkable functional group (B) 0.1 parts by weight to 15 parts by weight, and compound (C) 0.01 parts by weight to 2 Containing a polymerization unit derived from parts by weight, the weight ratio of the monomers input to prepare the copolymer is (A): (B) 85 to 99.9: 0.1 to 15, (A + B): In the case of (C), it may mean a case of 100: 0.01 to 2. When the range of the weight ratio is satisfied, the physical properties of the adhesive, for example, adhesive strength and durability, can be maintained excellent. In addition, when the copolymerizable monomer (B) having a crosslinkable functional group satisfies the weight ratio, it is possible to provide a sufficient crosslinking point for the copolymer contained in the adhesive composition together with the crosslinking agent described below.

In one example, the (meth) acrylic acid ester monomer (A) that can be used in the present application includes alkyl (meth) having an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, or 1 to 8 carbon atoms. An acrylate is exemplified. At this time, the alkyl group may be a straight chain, branched chain or cyclic. Such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) Acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, n-octyl (meth) acrylate, isobor Neil (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, etc. are exemplified, and one or more monomers may be used together.

In one example, as the copolymerizable monomer (B) having a crosslinkable functional group, a compound having a site that can be copolymerized with the (meth) acrylic acid ester monomer together with the crosslinkable functional group may be used. The types of monomers that can be used are not limited, and various types of copolymerizable monomers known in the adhesive field can be used. In one example, the copolymerizable monomer (B) having a crosslinkable functional group may have a hydroxy group or a carboxyl group. More specifically, as the copolymerizable monomer having a hydroxy group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl Hydroxyalkyl (meth) acrylates such as (meth) acrylate or 8-hydroxyoctyl (meth) acrylate, or 2-hydroxyethylene glycol (meth) acrylate or 2-hydroxypropylene glycol (meth) acrylic One or more of hydroxyalkylene glycol (meth) acrylates such as rate may be used, and (meth) acrylic acid, 2- (meth) acryloyloxy acetic acid, 3- (meth) as a copolymerizable monomer having a carboxyl group Acryloyloxy propyl acid, 4- (meth) acryloyloxy butyric acid, acrylic acid duplex, itaconic acid, maleic acid and maleic anhydride may be used. It is not limited thereto.

In one example, the compound (C) may be a compound represented by Formula 1 below.

[Formula 1]

In Formula 1, R1 is hydrogen or an alkyl group having 1 to 12 carbon atoms, and R2 is an alkylene group having 1 to 12 carbon atoms, wherein the alkyl group or alkylene group is substituted with an aryl group, hydroxy group, urethane group, ketone group, or ester group. It may be, and at least one of R3 to R5 may be an alkoxy group having 1 to 9 carbon atoms, an aryloxy group, or halogen. In one example, in Chemical Formula 1, R1 is hydrogen, R2 is an alkylene group having 1 to 5 carbon atoms, and at least one of R3 to R5 may be an alkoxy group having 1 to 3 carbon atoms or a halogen group.

As the compound (C) represented by Formula 1, (meth) acryloxy alkyl trimethoxysilane, (meth) acryloxy alkyl triethoxysilane, (meth) acryloxy alkyl dimethoxysilane, (meth) acryloxy alkyl 1 selected from the group consisting of diethoxysilane, (meth) acryloxy alkyl trichlorosilane, (meth) acryloxy alkyl dichlorosilane, (meth) acryloxy alkyl trihydroxysilane and (meth) acryloxy alkyl dihydroxysilane. More than one species may be used, but is not limited thereto.

The copolymer of the present application may include a polymerization unit derived from the compound (C) represented by Chemical Formula 1, so that a separate silane coupling agent may not be used. Accordingly, it is possible to prevent a problem caused by the use of a silane-based coupling agent in the prior art, for example, a decrease in adhesion due to volatilization of the silane-based coupling agent or a bubble generation problem. In addition, since the pressure-sensitive adhesive composition of the present application that does not contain a silane-based coupling agent can reduce the content of the curing agent that was added together when using the silane-based coupling agent in the prior art, the problem of durability decrease due to the addition of excessive curing agent or coating composition of the pressure-sensitive adhesive composition Problems such as decreased storage stability can also be solved. Furthermore, excellent durability reliability, light leakage prevention performance and reworkability can be secured even in harsh conditions such as heat resistance (80 ° C temperature) and / or moisture heat (60 ° C temperature, 90% humidity).

In one example, the compound (C) represented by the formula (1), the content of the (meth) acrylic acid ester monomer (A) and the content of the copolymerizable monomer (B) having the crosslinkable functional group to 100 parts by weight At this time, it may have a content of 0.01 to 2 parts by weight based on this. When the content is less than 0.01 part by weight, the effect of adding the compound (C) represented by the formula (1) is negligible, and when it exceeds 2 parts by weight, there is a problem that the adhesion between the polarizing plate and the adhesive is lowered. In one example, the compound (C) represented by the formula (1) may be included within the above range, 1.5 parts by weight or less, 1.0 parts by weight or less, and 0.05 parts by weight or more.

If necessary, the copolymer may further include a polymerization unit derived from any comonomer (D). An acrylic monomer is mentioned as an example of such a comonomer. More specifically, (meth) acrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide, N-butoxy methyl (meth) acrylamide, N-vinyl pyrrolidone or N-vinyl caprolactam, etc. The same nitrogen-containing monomer; Styrene-based monomers such as styrene or methyl styrene; Glycidyl group-containing monomers such as glycidyl (meth) acrylate; Or carboxylic acid vinyl esters such as vinyl acetate. One or more comonomers may be selected. In one example, the comonomer (D), the amount of the (meth) acrylic acid ester monomer (A) and the content of the copolymerizable monomer (B) having the crosslinkable functional group, when mixing the monomer for the copolymer production In addition, when it is 100 parts by weight, it may be added in a range of 0.1 parts by weight to 15 parts by weight based on this.

The method for producing the copolymer is not particularly limited. For example, a copolymer can be prepared using free radical polymerization. At this time, the polymerization initiator used may be an azo-based initiator, peroxide-based initiator, redox-based initiator, etc., but is not limited thereto.

The pressure-sensitive adhesive composition according to the present invention may further include a crosslinking agent. As the crosslinking agent, a polyfunctional crosslinking agent compound having at least two functional groups capable of reacting with the crosslinkable functional group of the copolymer, for example, about 2 to 5, may be used. Therefore, the type of the multifunctional crosslinking agent can be selected in consideration of the type of crosslinkable functional group present in the copolymer. In one example, isocyanate crosslinking agents, ie compounds having two or more isocyanate groups, for example 2 to 5, can be used. Examples of the isocyanate crosslinking agent include diols such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoboron diisocyanate, tetramethylxylene diisocyanate, xylene diisocyanate, or naphthalene diisocyanate. An isocyanate compound or a compound obtained by reacting the diisocyanate compound with a polyol can be used. At this time, for example, trimethylol propane or the like can be used as the polyol.

The multifunctional crosslinking agent may be included in the pressure-sensitive adhesive composition in an amount of 0.01 to 10 parts by weight or 0.01 to 5 parts by weight based on 100 parts by weight of the copolymer. The ratio can be adjusted in consideration of the desired degree of crosslinking, cohesion, adhesion, and durability. If it is out of the above range, the rate of viscosity increase of the coating liquid is increased, and the stability of the coating liquid of the adhesive composition may not be good. At this time, the stability may mean an appropriate viscosity range required for bar coating or the like. For example, when the content of the crosslinking agent exceeds 10 parts by weight, when compared with the initial viscosity of the coating solution, the viscosity increase rate of the 24-hour reference viscosity may be 10% or more and stability of the coating solution may be deteriorated.

 The pressure-sensitive adhesive composition may further include an antistatic agent. As the antistatic agent, for example, an ionic compound can be used. As the ionic compound, an organic salt or an inorganic salt may be exemplified.

As the inorganic salt, for example, a metal salt containing a metal ion as a cation can be used. The metal salt may include, for example, alkali metal cations or alkaline earth metal cations. As the cation, lithium ion (Li +), sodium ion (Na +), potassium ion (K +), rubidium ion (Rb +), cesium ion (Cs +), beryllium ion (Be2 +), magnesium ion (Mg2 +), calcium ion (Ca2 +) ), Strontium ions (Sr2 +) and barium ions (Ba2 +), or the like, or may be exemplified, for example, lithium ions, sodium ions, potassium ions, magnesium ions, calcium ions and barium ions. As described above, lithium ions may be used in consideration of ion stability and mobility.

As the organic salt, for example, an ionic compound containing an organic cation can be used. As an organic cation, an onium cation can be illustrated. As used herein, the term onium cation refers to an ion that is positively charged with a structure in which at least some of the charges are localized to atoms such as nitrogen (N), phosphorus (P), and / or sulfur (S). can do. The onium cation may be a cyclic or acyclic compound, and in the case of a cyclic, an aromatic or non-aromatic compound. The onium cation may further include other atoms, such as oxygen or carbon atoms, in addition to the nitrogen, phosphorus and / or sulfur. The onium cation may be optionally substituted by a substituent such as halogen, alkyl group or aryl group. For example, the acyclic compound may include one or four or more substituents, and the substituents may be cyclic or acyclic substituents, aromatic or non-aromatic substituents.

As the organic salt, a liquid material at room temperature can be used. As used herein, the term "room temperature" refers to a natural temperature that is not in a heated or cooled state, for example, a temperature of about 10 ° C to about 30 ° C, about 15 ° C to about 30 ° C, about 23 ° C or about 25 ° C. Can mean Through the use of a substance present in the liquid phase at room temperature, while ensuring adequate antistatic properties, it is possible to maintain excellent optical properties, adhesive properties and workability of the pressure-sensitive adhesive. In addition, even when the pressure-sensitive adhesive is left or stored for a long period of time, precipitation of the ionic compound from the pressure-sensitive adhesive and changes over time such as optical transparency or pressure-sensitive adhesive properties of the pressure-sensitive adhesive can be prevented.

As anions included in ionic compounds such as inorganic salts or organic salts, PF6-, AsF-, NO2-, fluoride (F-), chloride (Cl-), bromide (Br-), iodide (I- ), Perchlorate (ClO4-), hydroxide (OH-), carbonate (CO32-), nitrate (NO3-), trifluoromethanesulfonate (CF3SO3-), sulfonate (SO4-), hexafluoro Phosphate (PF6-), methylbenzenesulfonate (CH3 (C6H4) SO3-), p-toluenesulfonate (CH3C6H4SO3-), tetraborate (B4O72-), carboxybenzenesulfonate (COOH (C6H4) SO3-), flow Romethanesulfonate (CF3SO2-), benzoate (C6H5COO-), acetate (CH3COO-), trifluoroacetate (CF3COO-), tetrafluoroborate (BF4-), tetrabenzyl borate (B (C6H5) 4- ) Or trispentafluoroethyl trifluorophosphate (P (C2F5) 3F3-) and the like.

The ratio of the antistatic agent may be adjusted in consideration of the desired antistatic property, etc., and in one example, 0.1 parts by weight to 10 parts by weight, 0.1 parts by weight to 9 parts by weight, 0.1 parts by weight to 100 parts by weight of the copolymer 8 parts by weight, 0.5 parts by weight to 7 parts by weight, 0.5 parts by weight to 6 parts by weight, 0.5 parts by weight to 5 parts by weight or 1 part by weight to about 4 parts by weight may be included in the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition according to the present application, by adjusting the content of the antistatic agent to be included within the above-described range, it is possible to secure excellent properties of the antistatic ability.

The pressure-sensitive adhesive composition may further include a tackifier. Examples of the tackifier include hydrocarbon resins or hydrogenated products thereof, rosin resins or hydrogenated products thereof, rosin ester resins or hydrogenated products thereof, terpene resins or hydrogenated products thereof, terpene phenol resins or hydrogenated products thereof, polymerized rosin resins, or Polymerized rosin ester resins, and the like, but may be used by mixing one or more of them, but is not limited thereto. The tackifier may be included in the adhesive composition in an amount of 100 parts by weight or less, compared to 100 parts by weight of the copolymer.

In addition, the pressure-sensitive adhesive composition may further include at least one additive selected from the group consisting of curing agents, ultraviolet stabilizers, antioxidants, colorants, reinforcing agents, fillers, antifoaming agents, surfactants, and plasticizers.

In addition, in the pressure-sensitive adhesive composition, a gel fraction after implementing a crosslinked structure may be 90% by weight or less. The gel fraction can be calculated by the following general formula (1).

[Formula 1]

Gel fraction (%) = B / A × 100

In the general formula 1, A is the mass of the pressure-sensitive adhesive composition embodying a cross-linked structure, B is immersed in ethyl acetate at room temperature for 72 hours while the pressure-sensitive adhesive composition of mass A is put in a mesh having a size of 200 mesh. It shows the dry mass of the insoluble matter collected after the preparation.

By maintaining the gel fraction below 90% by weight, it is possible to maintain excellent workability, durability reliability and reworkability. The lower limit of the gel fraction is not particularly limited, and may be, for example, 0% by weight. However, the fact that the gel fraction is 0% by weight does not mean that crosslinking did not proceed at all in the pressure-sensitive adhesive composition. For example, in the pressure-sensitive adhesive composition having a gel fraction of 0% by weight, the pressure-sensitive adhesive composition or cross-linking with no crosslinking proceeded to some extent, but the degree of crosslinking was low, so that the gel could not be maintained in the mesh of the size of the 200 mesh. Leakage may also be included.

The pressure-sensitive adhesive composition can be used for various purposes. Typical applications include, but are not limited to, application to optical films and the like. The application to the optical film in the above may mean, for example, a pressure-sensitive adhesive composition that can be used for the purpose of attaching optical films or their laminates to other parts, such as liquid crystal panels, or between optical films.

This application also relates to an adhesive optical member. The adhesive optical member may include an optical film and an adhesive layer formed on at least one surface of the optical film. In the above, the pressure-sensitive adhesive layer is formed by the above-described pressure-sensitive adhesive composition, and may include, for example, the pressure-sensitive adhesive composition having a crosslinked structure.

The type of the optical film that may be included in the adhesive optical member is not particularly limited, and examples thereof include a polarizing plate, a polarizer, a polarizer protective film, a protective film of an optical film, a retardation film, a viewing angle compensation film, or a brightness enhancing film. You can. In this specification, the terms polarizer and polarizer refer to objects that are distinguished from each other. That is, the polarizer refers to a film, sheet, or element itself that exhibits a polarization function, and the polarizer refers to an optical element 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.

In one example, a carboxyl group may be present on the surface of the optical film included in the optical member. In this case, the pressure-sensitive adhesive layer may be attached to the surface where the carboxyl group is present. Through such a structure, adhesion between the epoxy or aziridine compound present in the pressure-sensitive adhesive layer and the carboxyl group may improve.

The carboxyl group may be naturally present on the surface depending on the type of the optical film. In another example, the carboxyl group on the surface of the optical film may be introduced by corona treatment. Therefore, a corona treatment layer may exist between the optical film of the optical member and the adhesive layer, and the adhesive layer may be attached to the corona treatment layer.

Corona treatment is a treatment method that increases wettability on a surface to be treated by electric discharge of a high frequency, and can be performed, for example, by irradiating a surface to be treated with corona generated by applying a high-frequency high voltage between two electrodes. A functional group such as a hydroxy group or a carboxyl group may be introduced to the surface. The method of performing the corona treatment is not particularly limited, and general methods in this field can be used without limitation.

The present application is also a polarizer; And an adhesive layer formed on one surface of the polarizer. In the above, the pressure-sensitive adhesive layer is formed by the above-described pressure-sensitive adhesive composition, and may include, for example, the pressure-sensitive adhesive composition having a crosslinked structure.

The type of the polarizer included in the polarizing plate is not particularly limited, and for example, a general type known in the field, such as a polyvinyl alcohol-based polarizer, can be employed without limitation.

The polarizer is a functional film that can extract only light that vibrates in one direction from incident light while vibrating in various directions. Such a polarizer may be, for example, a form in which a dichroic dye is adsorbed and oriented in a polyvinyl alcohol-based resin film. The polyvinyl alcohol-based resin constituting the polarizer can be obtained, for example, by gelling a polyvinyl acetate-based resin. In this case, the polyvinyl acetate-based resin that can be used may include a copolymer of vinyl acetate and other monomers copolymerizable therewith, as well as a homopolymer of vinyl acetate. Examples of monomers copolymerizable with vinyl acetate include, but are not limited to, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having ammonium groups, or mixtures of two or more. no. The gelation degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be further modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. In addition, the degree of polymerization of the polyvinyl alcohol-based resin may be about 1,000 to 10,000 or 1,500 to 5,000.

The polarizer stretches (ex. Uniaxially stretches) the polyvinyl alcohol-based resin film as described above, dyes the polyvinyl alcohol-based resin film with a dichroic dye, adsorbs the dichroic dye, and adsorbs the dichroic dye. The prepared polyvinyl alcohol-based resin film may be prepared through a process of treating with a boric acid aqueous solution and a process of washing with water after treating with a boric acid aqueous solution. In the above, as the dichroic dye, iodine or dichroic organic dye may be used.

The polarizing plate may further include a protective film attached to one side or both sides of the polarizer, and in this case, the pressure-sensitive adhesive layer may be formed on one side of the protective film. The type of the protective film is not particularly limited, and for example, cellulose-based films such as TAC (Triacetyl cellulose); Polyester film such as polycarbonate film or PET (poly (ethylene terephthalet)); Polyether sulfone-based films; Alternatively, a polyethylene film, a polypropylene film, a resin having a cyclo-based or norbornene structure, a polyolefin-based film produced using an ethylene-propylene copolymer, or the like, or a film having a laminated structure of two or more layers may be used, and more preferable For example, a cellulose-based film such as TAC can be used.

For example, in the structure in which the protective film is present as described above, an amine group, a carboxyl group, or a hydroxyl group may be present on the surface of the protective film, and an adhesive layer may be attached to the surface. In one example, in the polarizing plate, between the polarizer and the pressure-sensitive adhesive layer, there is a polarizer protective film having a hydroxyl group on the surface, and the pressure-sensitive adhesive layer may be attached to the surface of the protective film having the hydroxyl group.

The amine group, the carboxyl group or the hydroxyl group, as described above, the nature of the material, the protective film itself may be included, or may be introduced by corona treatment or the like. Accordingly, in the polarizing plate, a polarizer protective film having a corona-treated layer on the surface exists between the polarizer and the adhesive layer, and the adhesive layer may be attached to the corona-treated layer. The method of forming the corona treatment layer on the protective film is not particularly limited.

The polarizing plate may further include at least one functional layer selected from the group consisting of a protective layer, a reflective layer, an anti-glare layer, a retardation plate, a wide viewing angle compensation film and a brightness enhancing film.

The method of forming the pressure-sensitive adhesive layer on the polarizing plate or the optical member in the present application is not particularly limited, and for example, a method of directly coating and curing the pressure-sensitive adhesive composition to implement a crosslinked structure, or release treatment of a release film After coating and curing the pressure-sensitive adhesive composition on the surface to form a cross-linked structure, a method of transferring it may be used.

The method of coating the pressure-sensitive adhesive composition is not particularly limited, and for example, a method of applying the pressure-sensitive adhesive composition by a conventional means such as a bar coater may be used.

It is preferable from the viewpoint of performing a uniform coating process that the multifunctional crosslinking agent included in the pressure-sensitive adhesive composition in the coating process is controlled so that the crosslinking reaction of the functional group does not proceed, and through this, the crosslinking agent crosslinks in the curing and aging process after the coating operation. It is possible to improve the cohesive force of the pressure-sensitive adhesive by forming a structure, and improve the adhesion properties and cuttability.

In addition, it is preferable to perform the coating process after sufficiently removing bubble-inducing components such as volatile components or reaction residues inside the pressure-sensitive adhesive composition, and accordingly, the crosslink density or molecular weight of the pressure-sensitive adhesive is too low, resulting in poor elastic modulus and high temperature. Bubbles existing between the glass plate and the adhesive layer become large, thereby preventing a problem of forming a scattering body therein.

The present application also relates to a display device such as an LCD. The display device may include, for example, the aforementioned optical member or polarizing plate. When the display device is an LCD, the device may include a liquid crystal panel and the polarizing plate or optical member attached to one or both surfaces of the liquid crystal panel. The polarizing plate or the optical member may be attached to the liquid crystal panel by the above-described pressure-sensitive adhesive. As a liquid crystal panel applied to an LCD, for example, a panel of a passive matrix method such as a twisted nematic (TN) type, a super twisted nematic (STN) type, a ferroelectic (F) type, or a polymer dispersed (PD) type; An active matrix panel such as a two-terminal or three-terminal type; All well-known panels, such as an in-plane switching (IPS) panel and a vertical alignment (VA) panel, can be applied.

Other configurations of the display device, for example, types of upper and lower substrates such as color filter substrates or array substrates in LCDs are not particularly limited, and configurations known in this field can be employed without limitation.

Hereinafter, the pressure-sensitive adhesive composition of the present application will be described in detail through Examples and Comparative Examples. However, the scope of the present application is not limited by the examples presented below.

One. Coating properties  evaluation

When the adhesive polarizing plate was prepared using the coating liquid prepared in Examples and Comparative Examples, the viscosity was rapidly changed within 24 hours after the coating liquid was prepared, and whether the coating liquid was uniformly coated when coated on a flat plate.

<Evaluation criteria>

A: There is no increase in viscosity, and coating properties are uniform

B: There is a slight increase in viscosity, and the uniformity of the coating is partially reduced.

C: Viscosity rise is high, coating is impossible or very non-uniform

2. Heat resistance durability evaluation

The polarizing plates prepared in Examples and Comparative Examples were cut to a width of about 180 mm and a length of about 320 mm to prepare specimens, and attached to 19-inch commercial panels. Then, the panel is stored in an autoclave (50 ° C. and 5 atmospheres) for about 20 minutes to prepare a sample. After the prepared sample was maintained at 80 ° C for 500 hours, the occurrence of bubbles and peeling was observed with the naked eye and evaluated based on the following criteria.

<Evaluation criteria>

A: No bubbles and peeling were observed

B: Air bubbles and / or peeling occurred slightly.

C: Air bubbles and / or peeling occurrences were remarkably observed.

3. Moist heat  Durability evaluation

The polarizing plates prepared in Examples and Comparative Examples were cut to a width of about 180 mm and a length of about 320 mm to prepare specimens, and attached to 19-inch commercial panels. Then, the panel is stored in an autoclave (50 ° C. and 5 atmospheres) for about 20 minutes to prepare a sample. After the prepared sample was maintained at a temperature of 60 ° C. and a relative humidity of 90% for 500 hours, the occurrence of bubbles and peeling was visually observed to evaluate the following criteria.

<Evaluation criteria>

A: No bubbles and peeling were observed

B: Air bubbles and / or peeling occurred slightly.

C: Air bubbles and / or peeling occurrences were remarkably observed.

Manufacturing example  1: Preparation of random copolymer (A1)

In a 1 L reactor in which nitrogen gas was refluxed and a cooling device was installed to facilitate temperature control, 197 g of n-butyl acrylate (BA), 3 g of 4-hydroxybutyl acrylate (HBA), and 3-methacryloxy propyl trime 0.3 g of methoxy silane (MPTMS) was added, and 275 g of ethyl acetate (EAc) was added as a solvent. Subsequently, for oxygen removal, nitrogen gas was purged for about 60 minutes, and 0.1 g of AIBN (Azobisisobutyronitrile) as a reaction initiator was added while maintaining the temperature at 65 ° C. and reacted for about 8 hours to prepare a copolymer.

Manufacturing example  2 to 5: Preparation of random copolymers (A2, A3, B1 and B2)

Copolymers were prepared under the same conditions as in Preparation Example 1, except that they were adjusted as shown in Table 1 below.

Example  One

Preparation of coating solution (adhesive composition)

100 parts by weight of the block copolymer (A1) prepared in Preparation Example 1, 0.1 parts by weight of a crosslinking agent (Coronate L, manufactured by NPU, Japan) and 0.1 parts by weight of a dibutyltin dilaurate (DBTDL) as a curing catalyst were mixed, and ethyl acetate (ethyl) as a solvent. acetate) to prepare a coating solution (adhesive composition) by adjusting the coating solid content to be about 18% by weight.

Preparation of adhesive polarizing plate

The prepared coating solution was coated on a release treatment surface of release PET (poly (ethylene terephthalate)) (MRF-38, manufactured by Mitsubishi) having a thickness of 38 µm, which was molded to release the thickness after drying to about 23 µm. In the oven for about 3 minutes. After drying, the WV (Wide View) liquid crystal layer coated on one side of the polarizing plate (TAC / PVA / TAC laminated structure: TAC = triacetyl cellulose, PVA = polyvinyl alcohol-based polarizing film) WV liquid crystal layer on the release PET on the The formed coating layer was laminated to prepare an adhesive polarizing plate.

Example  2 to 4 and Comparative example  1 to 4

In preparing the pressure-sensitive adhesive composition (coating liquid), the pressure-sensitive adhesive composition (coating liquid) and the pressure-sensitive adhesive polarizing plate were prepared under the same conditions as in Example 1, except that each component and ratio were adjusted as shown in Table 4 below.

Table 3 below shows the evaluation results of the physical properties of the respective Examples and Comparative Examples.

Claims (13)

(Meta) acrylic acid ester monomer (A) derived from 85 parts by weight to 99.9 parts by weight, a copolymerizable monomer having a crosslinkable functional group (B) 0.1 parts by weight to 15 parts by weight, and compound (C) represented by the following formula (1) Copolymers having polymerized units; And a pressure-sensitive adhesive composition comprising a solvent,
The composition does not contain a silane-based coupling agent,
The ratio of the compound (C) represented by the formula (1) is 0.01 parts by weight to 2 parts by weight, compared to 100 parts by weight, including the (meth) acrylic acid ester monomer (A) and the copolymerizable monomer (B) having the crosslinkable functional group. Within the scope of wealth,
The crosslinkable functional group is a hydroxy group,
The composition is an adhesive composition further comprising a crosslinking agent that is a compound having two or more isocyanate groups capable of reacting with the crosslinkable functional group:
[Formula 1]

In Formula 1, R1 is hydrogen or an alkyl group having 1 to 12 carbon atoms, and R2 is an alkylene group having 1 to 12 carbon atoms, wherein the alkyl group or alkylene group is substituted with an aryl group, hydroxy group, urethane group, ketone group, or ester group. Can be, at least one of R3 to R5 is an alkoxy group having 1 to 9 carbon atoms, an aryloxy group, or halogen. delete delete delete The pressure-sensitive adhesive composition of claim 1, wherein the crosslinking agent is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the copolymer. The compound (C) represented by Formula 1 is (meth) acryloxy alkyl trimethoxysilane, (meth) acryloxy alkyl triethoxysilane, (meth) acryloxy alkyl dimethoxysilane, ( With (meth) acryloxy alkyl diethoxysilane, (meth) acryloxy alkyl trichlorosilane, (meth) acryloxy alkyl dichlorosilane, (meth) acryloxy alkyl trihydroxysilane and (meth) acryloxy alkyl dihydroxysilane At least one adhesive composition selected from the group consisting of. The pressure-sensitive adhesive composition of claim 1, further comprising an antistatic agent. The pressure-sensitive adhesive composition of claim 7, wherein the antistatic agent is included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the copolymer. The pressure-sensitive adhesive composition according to claim 1, wherein the gel fraction after implementing the crosslinked structure is 90% by weight or less. Optical film; And an adhesive layer formed on one side or both sides of the optical film and having an adhesive layer formed from the adhesive composition of claim 1. Polarizing film; And it is present on one or both sides of the polarizing film, the adhesive polarizing plate having an adhesive layer formed from the adhesive composition of claim 1. The pressure-sensitive adhesive polarizing plate according to claim 11, wherein the pressure-sensitive adhesive composition is included in the pressure-sensitive adhesive layer in a state in which a crosslinked structure is implemented. A display device comprising the adhesive optical laminate of claim 10 or the adhesive polarizing plate of claim 11 attached to one or both sides of a liquid crystal panel.