TWI680169B - Adhesive composition and adhesive film - Google Patents

Abstract

The present invention provides an adhesive composition and an adhesive film using the same, wherein the adhesive composition does not react with iodine contained in a polarizer of a polarizing plate, and can suppress the fading of the polarizing plate. And excellent antistatic properties. The adhesive composition is an adhesive composition containing an adhesive polymer, a cross-linking agent, and an antistatic agent, wherein the adhesive polymer contains (A) an alkyl group having a carbon number of C1 to C14 ( A copolymer composition of at least one of alkyl (meth) acrylate monomers and other copolymerizable vinyl monomers, said antistatic agent containing a melting point of 25 ° C to 50 ° C and being solid at a temperature of 25 ° C An ionic compound, which is composed of a cation and an anion, and contains an organic iodine compound.

Description

Adhesive composition and adhesive film

The present invention relates to an adhesive composition with excellent antistatic performance and an adhesive film using the adhesive composition.

Conventionally, in optical components such as polarizing plates and retardation plates that constitute components of liquid crystal displays, surface protection films for temporarily protecting the surfaces of optical components, bonding between optical components, or optical components and other components The bonded film for bonding is used. These adhesive films are sometimes used only in the process of manufacturing optical components, and are sometimes incorporated in final products such as liquid crystal displays.

When the adhesive film is peeled from optical components such as polarizing plates and retardation plates, if static electricity occurs, the peeling static electricity accompanied by static electricity may affect the failure of the electrical control circuit of the liquid crystal display. Therefore, an adhesive layer is required. Has excellent antistatic performance.

In terms of excellent antistatic performance, as a method for imparting antistatic performance to a surface protective film, a method of mixing an antistatic agent into a substrate film, and the like have been proposed. As antistatic agents, for example, (a) quaternary ammonium salts, pyridinium salts, and various cationic antistatic agents having cationic groups such as first to third amine groups; (b) sulfonate groups and sulfate esters are disclosed Base, phosphate base, phosphonate base, etc. Anionic antistatic agents with anionic groups; (c) amphoteric antistatic agents such as amino acids and amino sulfates; (d) nonionic antistatic agents such as amino alcohols, glycerols, and polyethylene glycols (E) a polymer-type antistatic agent obtained by polymerizing the antistatic agent as described above (Patent Document 1).

In addition, in recent years, proposals have been made to include such an antistatic agent directly in the adhesive layer, instead of including the base film or coating the surface of the base film.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1]: Japanese Patent Application Laid-Open No. 11-070629

For polarizing plates used in liquid crystal displays and the like, a polyvinyl alcohol (PVA) layer containing iodine molecules (I ₂ ) is usually used as a polarizer, and resin films are used as protective layers on both sides (also sometimes referred to as a polarizer). As a polarizer protective film), the resin film is made of cellulose triacetate (TAC), COP (cycloolefin polymer), acryl, and polypropylene (PP). Materials with excellent optical properties (such as transparency). Furthermore, the resin film of the protective layer may also function as a retardation film.

In recent years, as the thickness of liquid crystal displays and the like has become thinner, thinner polarizers, TAC films, and the like, which are protective films constituting polarizers, have also tended to be thinner. By thinning a TAC film or the like, when an adhesive film having antistatic properties is bonded to a polarizing plate, ions in an additive component contained in the adhesive composition The effect of the interaction of the sexual compound with the iodine contained in the polarizer is manifested. As a result, the problem that the iodine compound is precipitated in the polarizer and the polarizing plate (polarizer) is discolored may occur.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an adhesive composition and an adhesive film using the same, wherein the adhesive composition is not contained in a polarizer of a polarizing plate. The iodine reacts to suppress the discoloration of the polarizing plate and has excellent antistatic properties.

In order to solve the above-mentioned problems, the technical idea of the present invention is that the adhesive composition of the present invention can obtain an excellent antistatic agent by using an ionic compound that is solid at a temperature of 25 ° C. and contains an organic iodine compound as an antistatic agent. In addition, when the adhesive layer is bonded to the polarizing plate, since the iodine contained in the polarizer of the polarizing plate does not react with the antistatic agent, the discoloration of the polarizing plate can be suppressed.

In order to solve the above problems, the present invention provides an adhesive composition, which is an adhesive composition containing an adhesive polymer, a cross-linking agent, and an antistatic agent, wherein the adhesive polymer contains an (A) alkyl group. The copolymer composition of at least one of the (meth) acrylic acid alkyl ester monomers having C1 to C14 and other copolymerizable vinyl monomers, as the antistatic agent, contains a melting point of 25 ° C to 50 ° C It is a solid ionic compound at a temperature of 25 ° C., and the ionic compound is composed of a cation and an anion, and contains an organic iodine compound.

The organic iodine compound is contained in either the cation or the anion, or is contained in both the cation and the anion. Medium is better.

The other copolymerizable vinyl monomer in the above-mentioned adhesive polymer is (B) at least one of a copolymerizable vinyl monomer containing a carboxyl group and a hydroxyl group and a vinyl-containing copolymerizable vinyl monomer, with respect to 100 It is preferable that the copolymer composition by weight contains 0.1 to 10 parts by weight of the ionic compound (C) and 0.01 to 5 parts by weight of a difunctional or higher isocyanate compound as a crosslinking agent as an essential component.

The other copolymerizable vinyl monomer in the adhesive polymer is at least one of aromatic monomers, and contains 0.1 to 10 parts by weight of (C) the ionicity based on 100 parts by weight of the copolymer composition. The compound and 0.01 to 5 parts by weight of a difunctional or higher isocyanate compound as a crosslinking agent are preferably used as essential components.

The present invention also provides an adhesive film having a surface resistivity of 1.0 × 10 ⁺¹² Ω / □ or less of an adhesive layer formed by laminating the adhesive composition on one side of a substrate.

In addition, the present invention also provides an adhesive film in which an adhesive film is formed on one side of a substrate using the aforementioned adhesive composition to form an adhesive layer, and the adhesive layer is adhered to the adherend through the adhesive layer at 70 ° C. After curing (maintenance) at 10 ° C for 10 days, the adhesive force of the adhesive layer is 1.5 ~ 10N / 25mm.

In addition, the present invention also provides an adhesive film in which an adhesive layer is formed on one side of a substrate using the adhesive composition.

In addition, the present invention also provides an adhesive film, wherein the adhesive layer is formed by using the above-mentioned adhesive composition on one side of the release film, and has a release film / adhesive layer / release film structure.

In addition, the present invention provides an adhesive layer, which is an adhesive layer formed by using the above adhesive composition, and is used for bonding a polarizing plate and a display panel.

In addition, the present invention provides a polarizing plate with an adhesive layer using the above-mentioned adhesive film.

In addition, the present invention also provides an adhesive layer for bonding a polarizing plate and a display panel, wherein the polarizing plate has a retardation film composed of a triacetate-based material or a COP-based material. The thickness is 40 μm or less, and the total thickness of the polarizing plate is 150 μm or less.

The present invention also provides a film for bonding a polarizing plate constituent material using the above-mentioned adhesive film.

Based on the present invention, it is possible to provide an adhesive composition and an adhesive film using the adhesive composition. With the adhesive composition, the adhesive performance is not impaired under durability conditions and the like, and the fading of the polarizer can be suppressed. Excellent antistatic performance. Therefore, the above-mentioned problems existing in the adhesive composition of the antistatic agent containing an ionic compound in the prior art can be solved.

Hereinafter, the present invention will be described based on preferred embodiments.

The adhesive composition of the present invention is an adhesive composition containing an adhesive polymer, a cross-linking agent, and an antistatic agent. The antistatic agent contains a melting point of 25 ° C to 50 ° C at a temperature of 25 ° C. Are solid ionic compounds, The ionic compound is composed of a cation and an anion, and contains an organic iodine compound.

The ionic compound of the present invention is preferably an ionic compound composed of an anion and a cation, and more preferably an ionic compound composed of an organic anion and an organic cation.

The organic iodine compound contained in the ionic compound of the present invention is an organic compound having a carbon-iodine bond (CI bond). Examples of the organic iodine compound may include organic iodides (the RI), iodosobenzoic acyl compound (iodosyl compound) (R-IO ), iodonium compounds (R ₂ I ⁺ X ^-) and the like. Here, R represents an organic group. X represents an anion with respect to an iodonium cation. The iodine in the organic iodine compound is preferably contained as a substituent in the ionic compound, and is preferably a monovalent monoatomic iodine group (chemical formula: I-, English name: iodo-). The iodine substituent may be contained in any part of an aliphatic group such as an alkyl group, an aromatic ring such as benzene, a heterocyclic ring such as pyridine or imidazole, and the like.

The organic iodine compound is preferably contained in either the cation or the anion of the ionic compound, or is contained in both the cation and the anion. The ionic compound may be a combination of an organic anion having a CI bond and an organic or inorganic cation not having a CI bond, or a combination of an organic cation having a CI bond and an organic anion or inorganic anion having no CI bond. It is a combination of an organic anion having a CI bond and an organic cation having a CI bond.

Examples of the ionic compound having a melting point of 25 ° C. to 50 ° C. and a solid state at a temperature of 25 ° C. include a pyridinium cation, an imidazolium cation, a pyrimidine iron cation, a pyrazolium cation, a pyrrolium cation, and ammonium. Compounds such as nitrogen-containing cations such as cations, or phosphonium cations (phosphonium cations) and sulfonium cations (phosphonium cations). Specific examples thereof include hexafluorophosphate anion (PF ₆ ^-), thiocyanate (SCN ^-), alkylbenzene sulphonate ^{_{(RC 6 H 4 SO 3 -}} ), perchlorate (ClO ₄ ^-) , tetrafluoroborate (BF ₄ ^-), bis (fluorosulfonyl acyl) (PEI) root (FSI), bis (trifluoromethanesulfonyl acyl) (PEI) root (TFSI), triflate (TF ) And other inorganic or organic anion compounds. It is preferable to be solid at normal temperature (for example, 25 ° C). By selecting the chain length of the alkyl group, the position and number of the substituents, an ionic compound having a melting point of 25 ° C to 50 ° C can be obtained. The cation is preferably a 4th order nitrogen-containing onium cation, and examples include 1-alkylpyridinium (carbon atoms at the 2 to 6 position may or may not have a substituent), 4th order pyridinium cations, 1, Fourth-order imidazolium cations such as 3-dialkylimidazolium (carbon atoms at the 2, 4, and 5 positions may or may not have a substituent), and fourth-order ammonium cations such as tetraalkylammonium.

As the iodine-containing organic cation, as long as it is one or two or more organic cations such as pyridinium cation, imidazolium cation, pyrimidinium cation, pyrazole iron cation, pyrrolium cation, ammonium cation, phosphonium cation, and sulfonium cation. The I ^- substituent is sufficient, and examples thereof include pyridinium iodide, imidazolium iodide, pyrimidinium iodide, pyrazolium iodide, pyrrolidinium iodide, and alkylammonium iodide cations.

The iodine-containing organic anion may be any organic anion such as an aromatic sulfonic acid anion, an aliphatic sulfonic acid anion, or a carboxylic acid anion having one or two or more I ^- substituents. Examples thereof include an iodobenzenesulfonic acid anion. , Iodoalkanesulfonic acid anions, iodocarboxylic acid anions, and the like.

For the adhesive composition of the present invention, relative to 100 weight Part of the copolymer composition (base agent polymer) constituting the adhesive polymer, containing 0.1 to 10 parts by weight of an ion containing an organic iodine compound having a melting point of 25 ° C. to 50 ° C. and a solid at a temperature of 25 ° C. Sexual compounds are preferred. Since these ionic compounds have a low melting point and a long-chain alkyl group, it is presumed that they have high affinity with acrylic copolymers. Therefore, as the antistatic agent, an adhesive composition having excellent antistatic properties can be obtained.

As the adhesive polymer of the present invention, an acrylic copolymer (acrylic polymer) is preferred. In particular, the number of carbon atoms in the (A) alkyl group containing 50 parts by weight or more relative to 100 parts by weight of the copolymer composition is C1 to A copolymer of at least one of the C14 alkyl (meth) acrylate monomers is preferred.

Examples of the (A) alkyl (meth) acrylic acid alkyl ester monomer having a carbon number of C1 to C14 include butyl (meth) acrylate, isobutyl (meth) acrylate, and (meth) acrylic acid Amyl ester, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (formyl) (Nonyl) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, twelve (meth) acrylate Alkyl esters, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, and the like.

The proportion of the (A) alkyl (meth) acrylic acid alkyl ester monomer having a carbon number of C1 to C14 in 100 parts by weight of the copolymer composition is preferably 50 parts by weight or more.

Examples of the copolymerizable monomer copolymerized with the (A) alkyl (meth) acrylic acid alkyl ester monomer having a carbon number of C1 to C14 include vinyl groups and the like. Copolymerizable vinyl monomer of unsaturated polymerizable group. The copolymerizable vinyl monomer may have a hydroxyl group, an amino group, an amido group, an ether group, an aryl group, and the like as other functional groups. The functional group other than the polymerizable group may contain two or more in one molecule of each monomer.

Examples of the (B) hydroxyl-containing copolymerizable vinyl monomer include hydroxyl-containing (meth) acrylates such as hydroxyalkyl (meth) acrylate, and hydroxyl-containing copolymers such as hydroxyalkyl (meth) acrylamide. (Meth) acrylamide and the like. It is preferred that the hydroxy-containing copolymerizable vinyl monomer does not contain a carboxyl group.

Examples of the hydroxyl-containing (meth) acrylate include 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and (meth) ) 2-hydroxyethyl acrylate and the like.

Examples of the hydroxyl-containing (meth) acrylamide include N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, and N-hydroxyethyl (meth) acrylamine Amine, etc.

The ratio of the (B) hydroxyl-containing copolymerizable vinyl monomer in 100 parts by weight of the copolymer composition is preferably 0.1 to 10 parts by weight.

In the present invention, as the aryl group-containing copolymerizable vinyl monomer, in addition to the aryl group-containing (meth) acrylate, aromatic monomers such as styrene and methylstyrene may be mentioned.

Examples of the aryl-containing (meth) acrylate include benzyl (meth) acrylate, naphthyl (meth) acrylate, phenoxyethyl (meth) acrylate, and phenoxybutyl (meth) acrylate 2- (1-naphthyloxy) ethyl (meth) acrylate, 2- (2-naphthyloxy) ethyl (meth) acrylate, 6- (1-naphthyloxy) hexyl (meth) acrylate Ester, 6- (2-naphthyloxy) hexyl (meth) acrylate, 8- (1- Naphthyloxy) octyl ester, 8- (2-naphthyloxy) octyl (meth) acrylate, and the like. In order to obtain an adhesive layer with a high refractive index, it is preferable to mix at least one aromatic monomer.

Examples of copolymerizable vinyl monomers other than the above include: carboxyl-containing copolymerizable vinyl monomers such as (meth) acrylic acid; polyether group-containing copolymers such as polyalkylene glycol mono (meth) acrylate Copolymerizable vinyl monomers; nitrogen-containing copolymerizable vinyl monomers such as N-vinylpyrrolidone, (meth) acrylamide, and (meth) acrylonitrile.

In the present invention, the combination of copolymerizable vinyl monomers in the copolymer constituting the adhesive component is not particularly limited. First, a copolymer composed of at least one of an alkyl (meth) acrylate monomer having a carbon number of C1 to C14 and at least one of a hydroxyl-containing copolymerizable vinyl monomer may be mentioned. ; A copolymer composed of at least one of the alkyl (meth) acrylate monomers having a carbon number of C1 to C14 and at least one of other vinyl-containing copolymerizable vinyl monomers; In addition, at least one of alkyl (meth) acrylic acid alkyl monomers having a carbon number of C1 to C14, at least one of a hydroxyl-containing copolymerizable vinyl monomer, and other ethylene-containing monomers may also be mentioned. A copolymer composed of at least one of copolymerizable vinyl monomers based on a base; at least one of alkyl (meth) acrylic acid alkyl monomers having a carbon number of C1 to C14 and an aromatic monomer At least one composed of a copolymer. In addition, examples thereof include at least one of an alkyl (meth) acrylate monomer having a carbon number of C1 to C14, at least one of an aromatic monomer, and a hydroxyl-containing copolymerizable vinyl group. A copolymer composed of at least one of the monomers. In addition, at least one of alkyl (meth) acrylate monomers having a carbon number of C1 to C14 in the alkyl group may be mentioned. A copolymer composed of at least one of an aromatic monomer and at least one of other vinyl-containing copolymerizable vinyl monomers.

In the present invention, the copolymerizable vinyl monomer is preferably a monomer having at least one functional group such as a hydroxyl group as a functional group capable of reacting with a crosslinking agent. The acrylic copolymer preferably does not contain a carboxyl group-containing copolymerizable vinyl monomer and contains a hydroxyl group-containing copolymerizable vinyl monomer. As the functional group-containing monomer, only a hydroxyl-containing copolymerizable vinyl monomer may be used.

The crosslinking agent of the present invention is preferably a difunctional or higher isocyanate compound. The difunctional or higher isocyanate compound may be at least one or two or more selected from polyisocyanate compounds having at least two isocyanate (NCO) groups in one molecule. Polyisocyanate compounds include classifications of aliphatic isocyanates, aromatic isocyanates, acyclic isocyanates, and alicyclic isocyanates, and may be any of them. The difunctional isocyanate compound may be an isocyanate group-containing polyurethane compound produced by reacting a diisocyanate compound with a diol compound.

Examples of the trifunctional or higher isocyanate compounds include biuret-modified or isocyanurate-modified bifunctional isocyanate compounds (compounds having two NCO groups in one molecule), and Adducts (polyol modified products) and the like of trivalent or higher polyhydric alcohols (compounds having at least three or more OH groups in one molecule) such as methylolpropane (TMP) or glycerol. As the difunctional or higher isocyanate compound, only a trifunctional isocyanate compound or only a difunctional isocyanate compound may be used. In addition, a trifunctional isocyanate compound and a difunctional isocyanate compound may be used in combination.

In addition, as a difunctional or higher isocyanate compound, Examples: tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, etc. Bifunctional isocyanate compounds, and trifunctional or higher isocyanate compounds composed of their modifications (adducts, biurets, isocyanurates, etc.).

It is preferable that the adhesive composition of the present invention contains a difunctional or higher isocyanate compound as a crosslinking agent in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the copolymer composition.

In the adhesive composition of the present invention, as a component other than the above, a cross-linking catalyst such as a metal chelate compound, a cross-linking inhibitor such as a keto-enol tautomer compound, a surfactant, and curing promotion can be appropriately blended. Agents, plasticizers, fillers, curing inhibitors, processing aids, anti-aging agents, antioxidants and other well-known additives. These may be used alone or in combination of two or more.

The adhesive layer of the present invention can be formed using the adhesive composition of the present invention. After an adhesive layer is interposed therebetween and adhered to the adherend and aged at 70 ° C for 10 days, the adhesive force of the adhesive layer is 1.5 ~ 10N / 25mm. Examples of the adherend include optical glass plates such as alkali-free glass.

In the pressure-sensitive adhesive layer formed by laminating the pressure-sensitive adhesive composition on one surface of a substrate, the surface resistivity of the pressure-sensitive adhesive layer is preferably 1.0 × 10 ⁺¹² Ω / □ or less. If the surface resistivity of the adhesive layer is large, the performance of releasing static electricity generated by charging during peeling is poor. Therefore, by making the surface resistivity sufficiently small, it is possible to reduce the peeling static voltage caused by static electricity generated when the adhesive layer is peeled from the adherend, and to suppress the influence on the electrical control circuit and the like of the adherend.

The adhesive film of the present invention can be produced by forming the adhesive layer of the present invention on one side of a substrate or a release film.

As a base film for forming an adhesive layer or a release film (separator) for protecting an adhesive surface, a resin film such as a polyester film can be used.

For the base film, the surface of the resin film opposite to the side where the adhesive layer is formed can be protected with a silicone-based, fluorine-based release agent or coating agent, or silica particles. The antifouling treatment may be an antistatic treatment by applying or mixing an antistatic agent.

The release film is subjected to a release treatment with a silicone-based, fluorine-based release agent, or the like on the surface to be bonded to the adhesive surface of the adhesive layer.

A mold release film / adhesive layer / release film can be formed by laminating the release film-treated surfaces on both sides of one adhesive layer. In this case, by peeling the release films on both sides sequentially or simultaneously to expose the adhesive surface, it is possible to adhere to optical components such as optical films. Examples of the optical film include a polarizing film, a retardation film, an anti-reflection film, an anti-glare film, an ultraviolet absorbing film, an infrared absorbing film, an optical compensation film, and a brightness enhancement film.

The adhesive film of the present invention can be used in the bonding of various optical films for peripheral components of liquid crystal displays including polarizing plates, various optical films for touch panels, various optical films for electronic paper, and various optical films for organic EL.

In addition, the above-mentioned adhesive layer can be laminated on at least one side of these optical films to produce an optical film with an adhesive layer. Specifically, "optical film / adhesive layer / optical film", "optical film / adhesive layer / release film", "optical film / adhesive layer", "optical film / adhesive layer / optical film" / Adhesive layer / optical film "," optical film / "Adhesive layer / optical film / adhesive layer / release film", "release film / adhesive layer / optical film / adhesive layer / release film", etc.

For example, in the case of "optical film / adhesive layer / release film", in the case of having an adhesive layer protected by a release film, peeling off the release film exposes a film like "optical film / adhesive layer" The adhesive layer is bonded to other optical films to obtain a structure such as "optical film / adhesive layer / optical film" using the adhesive layer for interlayer bonding.

The adhesive film of the present invention is suitable for bonding a polarizing plate and a display panel. Examples of the display panel include a liquid crystal panel and an organic EL panel. The adhesive film of the present invention can be suitably used as an adhesive layer of a polarizing plate with an adhesive layer. As a constituent material of the polarizing plate, a retardation film having a retardation of λ / 4 or λ / 2 can be used. The adhesive layer of this invention can be used for bonding a retardation film and a polarizing plate. Examples of the retardation film include triacetate-based materials such as TAC, and COP-based materials. The polarizing plate may have a configuration such as “a retardation film / a polarizer / a retardation film”. In this case, the thickness can be reduced compared to a case where the retardation film is further attached to the polarizer of the “protective layer / polarizer / protective layer”. A protective film that can be removed by peeling may be provided on both sides or one side of the polarizing plate.

According to the present invention, even if an adhesive film is bonded to a polarizing plate, it is possible to suppress deterioration in polarization characteristics due to the release of iodine molecules contained in a polarizer. From the viewpoint of reducing the thickness of the polarizing plate, the thickness of the retardation film is preferably 40 μm or less, and two or more polarizing plate protective films or retardation films laminated on both sides of the polarizing plate and a layer included therebetween. The total thickness (the total thickness of the polarizing plate) is 150 μm or less. Between two or more polarizer protective films or retardation films, in addition to a polarizer composed of an iodine-containing PVA layer, etc., Contains adhesive layer, etc. The total thickness of the polarizing plate may be the thickness of a part assembled in a final product such as a liquid crystal display (except for the thickness of an unassembled part), or may not include a polyester protective film or the like.

[Example]

Hereinafter, the present invention will be specifically described based on examples.

<Manufacture of acrylic copolymer>

[Example 1]

In a reaction apparatus including a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction pipe, nitrogen was introduced, and the air in the reaction apparatus was replaced with nitrogen. Then, 100 parts by weight of butyl acrylate and 3.0 parts by weight of 6-hydroxyhexyl acrylate were added to the reaction apparatus, and a solvent (ethyl acetate) was simultaneously added. Then, azobisisobutyronitrile as a polymerization initiator was added dropwise over 2 hours and allowed to react at 65 ° C. for 6 hours to obtain an acrylic copolymer solution used in Example 1.

[Examples 2 to 4 and Comparative Examples 1 to 3]

Except that the composition of each monomer was adjusted as described in (A) and (B) in Table 1, the same operation as in the acrylic copolymer solution used in Example 1 described above was performed to obtain Example 2 used. ~ 4 and the acrylic copolymer solutions in Comparative Examples 1 ~ 3.

<Manufacture of an adhesive composition and an adhesive film>

[Example 1]

To the acrylic copolymer solution of Example 1 manufactured as described above, 2.0 parts by weight of 1-nonylpyridinium 2-iodobenzenesulfonate was added and stirred, and then 1.0 part by weight of Coronate HX (hexamethylene Diisocyanate compound, isocyanurate), and stirred to obtain the adhesive composition of Example 1. This adhesive composition was coated on a release film composed of a silicone resin-coated polyethylene terephthalate (PET) film, and then dried at 90 ° C to remove the solvent to obtain an adhesive. An adhesive sheet having a layer thickness of 25 μm.

Then, prepare a polyethylene terephthalate (PET) film with antistatic treatment and antifouling treatment on one side, and transfer the adhesive sheet to the polyethylene terephthalate (PET) film. On the side opposite to the surface subjected to antistatic treatment and antifouling treatment, a PET film / adhesive layer / release film (PET coated with silicone resin) Film) ". The adhesive film of Example 1 having a laminated structure.

[Examples 2 to 4 and Comparative Examples 1 to 3]

Except that the composition of the additives was adjusted as described in "Crosslinking Agent" and (C) in Table 2, the same operation as in the adhesive film of Example 1 was carried out to obtain Examples 2 to 4 and Comparative Examples 1 to 3 adhesive film.

In Table 1, all the numerical values in parentheses represent numerical values of the weight ratios of the respective components obtained by setting the total amount of the group (A) to 100 parts by weight. The group (A) is composed of an alkyl (meth) acrylate monomer or an aromatic monomer having a carbon number of C1 to C14. Group (B) is composed of a copolymerizable vinyl monomer containing a hydroxyl group or a carboxyl group. Group (C) is composed of ionic compounds.

In addition, the compound names corresponding to the abbreviations of the respective components used in Table 1 are shown in Table 2. Here, Coronate (registered trademark) HX, Coronate HL and Coronate L are trade names of Japan Polyurethane Industry Co., Ltd.

<Test method and evaluation>

After the adhesive films of Examples 1 to 4 and Comparative Examples 1 to 3 were aged at 23 ° C and 50% RH for 7 days, the release film (PET film coated with silicone resin) was peeled to make the adhesive The agent layer was exposed and used as a sample for measuring surface resistivity.

Furthermore, the adhesive film with the exposed adhesive layer was bonded to the surface of the polarizing plate through the adhesive layer, and then it was used as a sample for measuring the adhesive force.

<Surface resistivity>

After aging and before attaching the polarizer, peel off the release film (PET film coated with silicone resin) to expose the adhesive layer. Use resistivity meter HirestaUP-HT450 (Mitsubishi Chemical Analytech Co., Ltd.), and the surface resistivity (Ω / □) of the adhesive layer was measured.

<Adhesion>

After the adhesive layer (film) was bonded to the polarizing plate, the polarizing plate with the adhesive layer was bonded to alkali-free glass (trade name: "Eagle XG") manufactured by Corning Incorporated. Then, it was left to stand at 70 ° C for 10 days, and then taken out to room temperature for 1 hour, and then the adhesion force (N / 25mm) when the sample was peeled at 180 ° at a tensile speed of 300mm / min was measured. .

<Fading properties>

After the adhesive layer film was bonded to the polarizing plate, the polarizing plate with the adhesive layer was bonded to alkali-free glass (trade name: "Eagle XG") manufactured by Corning Incorporated. Then, after leaving it for 100 hours in an environment of 85 ° C. and a relative humidity of 85%, it was taken out and left at room temperature for 1 hour, and the discoloration of the polarizing plate was observed. The evaluation target criteria are as follows: when the polarizing plate is not discolored, the evaluation is "○"; when the polarizing plate is partially discolored, the evaluation is "△"; in the case where the polarizing plate was discolored, the evaluation was "×".

The evaluation results are shown in Table 3. In the surface resistivity, “mE + n” is used to express “m × 10 ^{+ n} ” (where m is an arbitrary real number and n is a positive integer).

The types of polarizing plates are as follows.

Polarizing plate A (total thickness: 135 μm; retardation film: TAC with 40 μm thickness)

Polarizing plate B (total thickness: 115 μm; retardation film: TAC with 25 μm thickness)

Polarizing plate C (total thickness: 90 μm; retardation film: TAC with 20 μm thickness)

Polarizer D (total thickness: 135 μm; retardation film: COP with 40 μm thickness)

Polarizing plate E (total thickness: 180 μm; retardation film: TAC with 80 μm thickness)

For the adhesive films of Examples 1 to 4, the surface resistivity was low, the adhesive force was appropriate, and no discoloration occurred even when the polarizing plate was thin. That is, at the same time, all of the following performance requirements are satisfied: (1) the adhesion performance is not damaged under durability conditions, etc .; (2) the fading of the polarizing plate can be suppressed; and (3) the antistatic property is excellent.

Since the adhesive films of Comparative Examples 1 and 3 do not contain organic iodination, It is an ionic compound of the compound, and therefore cannot suppress the discoloration of the polarizing plate.

Since the adhesive film of Comparative Example 2 does not contain an ionic compound, it has high surface resistivity and does not have antistatic properties. In addition, it may be because the copolymer of the adhesive component is obtained by copolymerizing a carboxyl-containing copolymerizable vinyl monomer. After being adhered to an adherend and aged at 70 ° C for 10 days, the adhesive is adhered. The adhesive force of the agent layer becomes very strong.

As such, the adhesive films of Comparative Examples 1 to 3 failed to satisfy all of the following performance requirements at the same time: (1) the adhesive performance was not impaired under durability conditions, etc .; (2) the fading of the polarizing plate was suppressed; (3) the resistance Excellent static electricity.

Claims (12)

An adhesive composition is an adhesive composition containing an adhesive polymer, a cross-linking agent, and an antistatic agent, characterized in that the adhesive polymer contains (A) alkyl groups having carbon numbers of C1 to C14 A copolymer composition of at least one of (meth) acrylic acid alkyl ester monomers and other copolymerizable vinyl monomers. The antistatic agent contains a melting point of 25 ° C to 50 ° C and is solid at a temperature of 25 ° C. An ionic compound consisting of a cation and an anion and containing an organic iodine compound having a carbon iodine bond (CI bond). The adhesive composition according to item 1 of the patent application scope, wherein the organic iodine compound is contained in either the cation or the anion, or is contained in both the cation and the anion. The adhesive composition as described in claim 1 or 2, wherein the other copolymerizable vinyl monomer of the adhesive polymer is (B) a copolymerizable vinyl monomer having no carboxyl group and having a hydroxyl group, and At least one of vinyl-containing copolymerizable vinyl monomers contains 0.1 to 10 parts by weight of the ionic compound (C) and 0.01 to 5 parts by weight of the copolymer composition based on 100 parts by weight of the copolymer composition. A difunctional or higher isocyanate compound as a crosslinking agent is an essential component. The adhesive composition according to item 1 or 2 of the scope of patent application, wherein the other copolymerizable vinyl monomer of the adhesive polymer is at least one kind of aromatic monomer, relative to 100 parts by weight of the copolymer. The composition contains, as essential components, 0.1 to 10 parts by weight of the ionic compound (C) and 0.01 to 5 parts by weight of a difunctional or higher-functional isocyanate compound as a crosslinking agent. An adhesive film, characterized in that, on one side of a substrate, an adhesive layer formed by laminating the adhesive composition described in any one of claims 1 to 4 of the patent application scope, and the surface resistivity of the adhesive layer It is 1.0 × 10 ⁺¹² Ω / □ or less. An adhesive film is characterized in that an adhesive film of an adhesive layer is formed on one side of a substrate using the adhesive composition described in any one of claims 1 to 4, and the adhesive is interposed therebetween. After the adhesive layer is adhered to the adherend, and after aging at 70 ° C for 10 days, the adhesive force of the adhesive layer is 1.5 ~ 10N / 25mm. An adhesive film is characterized in that an adhesive layer is formed on one side of a substrate by using the adhesive composition described in any one of claims 1 to 4. An adhesive film, characterized in that, on one side of a release film, an adhesive layer is formed by using the adhesive composition described in any one of claims 1 to 4, and has a release film / adhesion Composition of the agent layer / release film. An adhesive layer is an adhesive layer formed by using the adhesive composition described in any one of claims 1 to 4 for applying a polarizing plate and a display panel. A polarizing plate with an adhesive layer uses the adhesive film described in item 8 of the scope of patent application. The adhesive layer described in item 9 of the scope of patent application is an adhesive layer for bonding the polarizing plate and the display panel described in item 9 of the scope of patent application, and the polarizer has a triacetate-based material. Or a COP-based material, the thickness of the retardation film is 40 μm or less, and the total thickness of the polarizing plate is 150 μm or less. A film for bonding polarizing plate constituent materials, which uses the adhesive film described in item 8 of the scope of patent application.