Polarizing film with pressure-sensitive adhesive layer, and optical device

Abstract

Provided are: a polarizing film with a pressure-sensitive adhesive layer, the polarizing film being capable of exhibiting both highly reliable antistatic properties and excellent corrosion resistance; and an optical device including the polarizing film with a pressure-sensitive adhesive layer.　A polarizing film with a pressure-sensitive adhesive layer according to an embodiment of the present invention comprises a pressure-sensitive adhesive layer and a polarizing film. The pressure-sensitive adhesive layer is made of a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition comprises a base polymer and an ionic compound, wherein the ionic compound comprises a cationic species and an anionic species, the anionic species being at least one anion selected from the group consisting of borate anions and dicyanamide anions.

Description

Polarizing film with pressure-sensitive adhesive layer and optical device

[0001] The present invention relates to a polarizing film with a pressure-sensitive adhesive layer, and also to an optical device including such a polarizing film with a pressure-sensitive adhesive layer.

[0002] A polarizing film with a pressure-sensitive adhesive layer is sometimes used as a member for constituting an optical member.

[0003] Optical components and polarizing films with pressure-sensitive adhesive layers as described above have high electrical insulation properties and generate static electricity due to friction or peeling. For example, if a voltage is applied to a liquid crystal while such static electricity remains, there is a risk that the orientation of the liquid crystal molecules may be lost or the liquid crystal panel may be damaged. Furthermore, the presence of static electricity may attract dust or reduce workability.

[0004] A technique has been reported in which an ionic compound is incorporated as an antistatic agent into the adhesive layer to impart antistatic properties to the adhesive film (for example, Patent Document 1).

[0005] However, when a polarizing film with a pressure-sensitive adhesive layer including a conventional antistatic agent-containing pressure-sensitive adhesive layer is used, for example, as a component for constituting an optical member, there is a problem that corrosion occurs in the electrode portion of the adherend. In particular, when an optical device including a polarizing film with a pressure-sensitive adhesive layer is used in a harsh environment such as a high-temperature, high-humidity environment, there is a problem that the above-mentioned corrosion occurs significantly. Furthermore, when a polarizing film with a pressure-sensitive adhesive layer is used in such a harsh environment, there is a problem that the reliability of the antistatic property decreases, and for example, the surface resistance value of the pressure-sensitive adhesive layer fluctuates.

[0006] Japanese Patent Application Laid-Open No. 2023-164531

[0007] An object of the present invention is to provide a polarizing film with a pressure-sensitive adhesive layer that can exhibit both highly reliable antistatic properties and excellent corrosion resistance, and an optical device that includes the polarizing film with a pressure-sensitive adhesive layer.

[0008] [1] A pressure-sensitive adhesive layer-attached polarizing film according to an embodiment of the present invention includes a pressure-sensitive adhesive layer and a polarizing film. The pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition includes a base polymer and an ionic compound. The ionic compound comprises a cation species and an anion species, and the anion species is at least one selected from the group consisting of a borate anion and a dicyanamide anion. [2] In the pressure-sensitive adhesive layer-attached polarizing film described in [1] above, the cation species may be at least one selected from the group consisting of an onium cation and a metal cation. [3] In the pressure-sensitive adhesive layer-attached polarizing film described in [1] or [2] above, the borate anion does not need to contain both elemental fluorine and elemental sulfur. [4] In the pressure-sensitive adhesive layer-attached polarizing film described in any one of [1] to [3] above, the base polymer may be at least one selected from an acrylic polymer, a polyol, and a urethane prepolymer. [5] In the pressure-sensitive adhesive layer-attached polarizing film described in [4] above, the base polymer may be an acrylic polymer, and the monomer components constituting the acrylic polymer may include at least one selected from the group consisting of a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms, and a (meth)acrylic acid ester having an OH group, and (meth)acrylic acid. [6] In the pressure-sensitive adhesive layer-attached polarizing film described in [4] above, the base polymer may be an acrylic polymer, and the monomer components constituting the acrylic polymer may include at least one selected from the group consisting of an amide group-containing monomer, an aromatic ring-containing (meth)acrylate, and a (meth)acrylic acid alkoxyalkyl ester. [7] In the pressure-sensitive adhesive layer-attached polarizing film described in any one of [1] to [6] above, the amount of the ionic compound per 100 parts by weight of the base polymer may be 0.001 to 30 parts by weight. [8] An optical device according to an embodiment of the present invention includes the pressure-sensitive adhesive layer-attached polarizing film described in any one of [1] to [7] above.

[0009] According to the present invention, it is possible to provide a polarizing film with a pressure-sensitive adhesive layer that can exhibit both highly reliable antistatic properties and excellent corrosion resistance, and an optical device that includes the polarizing film with a pressure-sensitive adhesive layer.

[0010] 1 is a schematic cross-sectional view of a polarizing film with a pressure-sensitive adhesive layer according to one embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of a pressure-sensitive adhesive film as an example of use of a pressure-sensitive adhesive layer that can be used in a polarizing film with a pressure-sensitive adhesive layer according to an embodiment of the present invention.

[0011] In this specification, the expression "(meth)acrylic" means "acrylic and / or methacrylic", the expression "(meth)acrylate" means "acrylate and / or methacrylate", the expression "(meth)allyl" means "allyl and / or methallyl", and the expression "(meth)acrolein" means "acrolein and / or methacrolein". Furthermore, in this specification, the expression "acid (salt)" means "acid and / or its salt". Examples of salts include alkali metal salts and alkaline earth metal salts, and specific examples include sodium salts and potassium salts.

[0012] In this specification, the term "main component" means preferably 50% by weight to 100% by weight, more preferably 60% by weight to 100% by weight, even more preferably 70% by weight to 100% by weight, particularly preferably 80% by weight to 100% by weight, and most preferably 90% by weight to 100% by weight.

[0013] <<1. Overall Configuration>> A pressure-sensitive adhesive layer-attached polarizing film 100 according to one embodiment of the present invention has a polarizing film 10 and a pressure-sensitive adhesive layer 20, in this order, as shown in the schematic cross-sectional view of Fig. 1. In Fig. 1, an anchor layer 30 is provided between the polarizing film 10 and the pressure-sensitive adhesive layer 20, but the anchor layer 30 is an optional member and does not necessarily have to be provided. Any appropriate anchor layer can be adopted as the anchor layer as long as it does not impair the effects of the present invention.

[0014] A surface treatment layer 40 can be provided on the polarizing film 10 on the side opposite to the pressure-sensitive adhesive layer 20. Fig. 1 illustrates a case where the pressure-sensitive adhesive layer-attached polarizing film 100 has a surface treatment layer 40. Any appropriate surface treatment layer can be adopted as the surface treatment layer as long as it does not impair the effects of the present invention.

[0015] 1 , a release liner (sometimes referred to as a release sheet or separator) can be provided on the exposed surface of the pressure-sensitive adhesive layer 20 of the pressure-sensitive adhesive layer-attached polarizing film 100, and a surface protective film can be provided on the exposed surface of the polarizing film 10. Furthermore, each component can be appropriately provided with an easy-adhesion layer or subjected to various easy-adhesion treatments such as corona treatment and plasma treatment.

[0016] Examples of release liners include release liners in which the surface of a substrate (liner substrate) such as paper or plastic film is treated with silicone, and release liners in which the surface of a substrate (liner substrate) such as paper or plastic film is laminated with a polyolefin resin.

[0017] Examples of plastic films usable as liner substrates include polyethylene films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polybutylene terephthalate films, polyurethane films, and ethylene-vinyl acetate copolymer films.

[0018] The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, even more preferably 5 μm to 400 μm, and particularly preferably 10 μm to 300 μm.

[0019] The pressure-sensitive adhesive layer-attached polarizing film according to an embodiment of the present invention can be produced by any appropriate method as long as the effects of the present invention are not impaired. Examples of such methods include providing a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition on the surface of a polarizing film (or the surface of the anchor layer if an anchor layer is provided on the polarizing film), and examples include a method (transfer method) in which the pressure-sensitive adhesive composition is applied to a release-treated separator or the like, and heated or dried as necessary to form a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is transferred to the surface of a polarizing film (or the surface of the anchor layer if an anchor layer is provided on the polarizing film), and a method (direct method) in which the pressure-sensitive adhesive composition is applied to the surface of a polarizing film (or the surface of the anchor layer if an anchor layer is provided on the polarizing film), and the like, ... pressure-sensitive adhesive layer is formed.

[0020] Any appropriate conditions for the heating and drying may be adopted as long as the effects of the present invention are not impaired. Examples of the application method include a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, an air knife coater, a spray coater, a comma coater, a direct coater, a roll brush coater, and a die coater.

[0021] <<2. Pressure-sensitive adhesive layer and pressure-sensitive adhesive composition>> The pressure-sensitive adhesive layer may be a single layer or may be two or more layers. The pressure-sensitive adhesive layer is typically a single layer.

[0022] In one embodiment, the thickness of the pressure-sensitive adhesive layer is preferably 0.5 μm to 200 μm, more preferably 1 μm to 150 μm, even more preferably 5 μm to 100 μm, and particularly preferably 10 μm to 80 μm, in terms of being able to further exhibit the effects of the present invention.

[0023] Another embodiment of the thickness of the pressure-sensitive adhesive layer is preferably 0.5 μm to 100 μm, more preferably 1 μm to 50 μm, even more preferably 2 μm to 40 μm, and particularly preferably 3 μm to 30 μm, in terms of being able to further exhibit the effects of the present invention.

[0024] The pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition.

[0025] The PSA composition contains, as a base polymer, at least a portion of the monomer components (raw monomer components) that constitute the polymer (typically a crosslinked polymer) that will ultimately be contained as the main component in the PSA layer, provided that the raw monomer components do not include a crosslinking agent.

[0026] When the base polymer is a polymer of all of the raw material monomer components, this base polymer may be referred to as a "complete polymer." However, a complete polymer does not necessarily mean that the polymerization conversion rate (the ratio of the amount of raw material monomer components used in polymerization to the total amount of raw material monomer components) is 100% by weight, and the polymerization conversion rate is preferably 85% by weight to 100% by weight, but may also be 90% by weight to 100% by weight, 95% by weight to 100% by weight, or 98% by weight to 100% by weight.

[0027] When the base polymer is a polymer of a portion of the raw monomer components, this base polymer may be referred to as a "partial polymer." The partial polymer may typically be in a syrup-like state (a viscous liquid) mixed with raw monomer components (unreacted monomer components) that have not been partially polymerized. This syrup-like mixture of the partial polymer and the unreacted monomer components may be referred to as a "monomer syrup." The polymerization conversion rate in the partial polymer is preferably 1% by weight or more and less than 85% by weight, and may be 1% by weight to 70% by weight, 3% by weight to 60% by weight, 3% by weight to 50% by weight, 5% by weight to 40% by weight, or 5% by weight to 35% by weight.

[0028] The PSA composition contains a base polymer and an ionic compound. The base polymer may be of only one type or may contain two or more types of ionic compounds.

[0029] Any appropriate base polymer may be used as the base polymer as long as it does not impair the effects of the present invention. Preferably, the base polymer is at least one selected from the group consisting of an acrylic polymer, a polyol, and a urethane prepolymer.

[0030] Representative embodiments in which the base polymer is an acrylic polymer include an embodiment in which the base polymer is an acrylic polymer (A) and an embodiment in which the base polymer is an acrylic polymer (B). The acrylic polymer (A) and the acrylic polymer (B) will be described in detail later.

[0031] In an embodiment in which the base polymer is an acrylic polymer (A), the pressure-sensitive adhesive composition is expressed as an acrylic pressure-sensitive adhesive composition (A), a pressure-sensitive adhesive formed from the acrylic pressure-sensitive adhesive composition (A) is expressed as an acrylic pressure-sensitive adhesive (A), and a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive formed from the acrylic pressure-sensitive adhesive composition (A) is expressed as an acrylic pressure-sensitive adhesive layer (A).

[0032] In an embodiment in which the base polymer is an acrylic polymer (B), the pressure-sensitive adhesive composition is expressed as an acrylic pressure-sensitive adhesive composition (B), a pressure-sensitive adhesive formed from the acrylic pressure-sensitive adhesive composition (B) is expressed as an acrylic pressure-sensitive adhesive (B), and a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive formed from the acrylic pressure-sensitive adhesive composition (B) is expressed as an acrylic pressure-sensitive adhesive layer (B).

[0033] In an embodiment in which the base polymer is a polyol, the pressure-sensitive adhesive composition is expressed as a urethane-based pressure-sensitive adhesive composition (C), the pressure-sensitive adhesive formed from the urethane-based pressure-sensitive adhesive composition (C) is expressed as a urethane-based pressure-sensitive adhesive (C), and the pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive formed from the urethane-based pressure-sensitive adhesive composition (C) is expressed as a urethane-based pressure-sensitive adhesive layer (C).

[0034] In an embodiment in which the base polymer is a urethane prepolymer, the pressure-sensitive adhesive composition is expressed as a urethane-based pressure-sensitive adhesive composition (D), the pressure-sensitive adhesive formed from the urethane-based pressure-sensitive adhesive composition (D) is expressed as a urethane-based pressure-sensitive adhesive (D), and the pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive formed from the urethane-based pressure-sensitive adhesive composition (D) is expressed as a urethane-based pressure-sensitive adhesive layer (D).

[0035] Generally, known urethane polymers include "prepolymer-type urethane polymers" produced by reacting a urethane prepolymer with a polyfunctional isocyanate compound, and "one-shot-type urethane polymers" produced by directly reacting a polyol with a polyfunctional isocyanate compound without using a urethane prepolymer. Urethane prepolymers are typically obtained by reacting a polyol with a polyfunctional isocyanate compound, and have hydroxyl groups at the molecular terminals.

[0036] The urethane polymer contained in the urethane-based pressure-sensitive adhesive (C) is typically a one-shot urethane polymer. The one-shot urethane polymer may be of only one type, or may be of two or more types. The one-shot urethane polymer is obtained by reacting a polyol (not a urethane prepolymer) as a base polymer with a polyfunctional isocyanate compound. Therefore, when the urethane polymer is a one-shot urethane polymer, the urethane-based pressure-sensitive adhesive composition that forms the urethane-based pressure-sensitive adhesive typically contains a polyol (not a urethane prepolymer) as a base polymer.

[0037] The urethane polymer contained in the urethane-based pressure-sensitive adhesive (D) is typically a prepolymer-type urethane polymer. The prepolymer-type urethane polymer may be of only one type, or may be of two or more types. The prepolymer-type urethane polymer is obtained by reacting a urethane prepolymer as a base polymer with a polyfunctional isocyanate compound. Therefore, when the urethane polymer is a prepolymer-type urethane polymer, the urethane-based pressure-sensitive adhesive composition that forms the urethane-based pressure-sensitive adhesive typically contains a urethane prepolymer as a base polymer.

[0038] The content of the base polymer in the pressure-sensitive adhesive composition can be any appropriate content ratio, depending on the type of base polymer used, the type of ionic compound, etc., as long as the effects of the present invention are not impaired. The content of the base polymer in the pressure-sensitive adhesive composition, calculated as solid content, is preferably 1 wt% to 99.9 wt%, may be 5 wt% to 99.9 wt%, 10 wt% to 99.9 wt%, 20 wt% to 99.9 wt%, 30 wt% to 99.9 wt%, 40 wt% to 99.9 wt%, 50 wt% to 99.9 wt%, 60 wt% to 99.9 wt%, 65 wt% to 99.9 wt%, 70 wt% to 99.9 wt%, or may be 75 wt% to 99.9 wt%.

[0039] The content of the ionic compound in the pressure-sensitive adhesive composition may be any appropriate content ratio, depending on the type of base polymer and the type of ionic compound used, as long as the effects of the present invention are not impaired. In order to further exhibit the effects of the present invention, the content of the ionic compound in the pressure-sensitive adhesive composition is preferably 0.001 to 3,000 parts by weight, may be 0.001 to 2,000 parts by weight, may be 0.001 to 1,000 parts by weight, may be 0.001 to 500 parts by weight, may be 0.001 to 300 parts by weight, may be 0.001 to 100 parts by weight, may be 0.001 to 50 parts by weight, may be 0.001 to 300 parts by weight, may be 0.001 to 100 parts by weight, may be 0.001 to 50 parts by weight, or may be 0.001 to 30 parts by weight, relative to 100 parts by weight of the base polymer.

[0040] In one embodiment, the content of the ionic compound in the PSA composition is more preferably 0.001 to 10 parts by weight, even more preferably 0.005 to 7 parts by weight, particularly preferably 0.01 to 5 parts by weight, and most preferably 0.05 to 3 parts by weight, relative to 100 parts by weight of the base polymer.

[0041] In another embodiment, the content of the ionic compound in the PSA composition is more preferably 0.001 to 20 parts by weight, even more preferably 0.001 to 10 parts by weight, particularly preferably 0.01 to 10 parts by weight, and most preferably 0.05 to 10 parts by weight, relative to 100 parts by weight of the base polymer. This embodiment may be, for example, a content suitable for a PSA composition that forms a PSA constituting the PSA layer in an optical laminate including a polarizing film and a PSA layer (i.e., a polarizing film with a PSA layer according to an embodiment of the present invention).

[0042] As described above, typical examples of the pressure-sensitive adhesive composition according to the embodiment of the present invention include the acrylic pressure-sensitive adhesive composition (A), the acrylic pressure-sensitive adhesive composition (B), the urethane pressure-sensitive adhesive composition (C), and the urethane pressure-sensitive adhesive composition (D).

[0043] The acrylic pressure-sensitive adhesive composition (A) contains an acrylic polymer (A) as a base polymer and an ionic compound. The acrylic pressure-sensitive adhesive composition (A) will be described in detail later.

[0044] The acrylic pressure-sensitive adhesive composition (B) contains an acrylic polymer (B) as a base polymer and an ionic compound. The acrylic pressure-sensitive adhesive composition (B) will be described in detail later.

[0045] The urethane-based pressure-sensitive adhesive composition (C) contains a polyol as a base polymer and an ionic compound. The urethane-based pressure-sensitive adhesive composition (C) will be described in detail later.

[0046] The urethane-based pressure-sensitive adhesive composition (D) contains a urethane prepolymer as a base polymer and an ionic compound. The urethane-based pressure-sensitive adhesive composition (D) will be described in detail later.

[0047] <2-1. Ionic Compound> The PSA composition contains an ionic compound. The ionic compound comprises a cationic species and an anionic species. Any appropriate ionic compound can be used as such an ionic compound as long as it does not impair the effects of the present invention.

[0048] The ionic compound may be an ionic liquid, which means a molten salt (ionic compound) that is liquid at 25°C.

[0049] In terms of being able to exhibit the effects of the present invention, the anion species is preferably at least one selected from the group consisting of borate anion and dicyanamide anion. By employing at least one selected from the group consisting of borate anion and dicyanamide anion as the anion species, the effects of the present invention can be exhibited.

[0050] Examples of borate anions include bis(oxalate)borate, bis(mandelato)borate, bis(salicylato)borate, bis(malonato)borate, bis(succinato)borate, bis(glutolato)borate, and bis(adipato)borate. Of these, bis(oxalate)borate represented by the following chemical formula (A) is preferred in that it can further exhibit the effects of the present invention.

[0051]

[0052] The borate anion preferably does not contain at least one selected from the group consisting of fluorine and sulfur, and more preferably does not contain both fluorine and sulfur. By employing a borate anion that does not contain at least one selected from the group consisting of fluorine and sulfur (preferably does not contain both fluorine and sulfur) as the anion species, the effects of the present invention can be more effectively exhibited.

[0053] In the borate anion, an oxygen atom is preferably directly bonded to a boron atom, which can exert the effect of further increasing the electrical conductivity.

[0054] Dicyanamide anion is (CN)N - It is an anion represented by the formula:

[0055] As the cation species, any appropriate cation can be used as long as it does not impair the effects of the present invention. In terms of being able to further exhibit the effects of the present invention, such a cation is preferably at least one selected from the group consisting of onium cations and metal cations.

[0056] As the onium cation, any appropriate onium cation can be adopted as long as it does not impair the effects of the present invention. In terms of being able to further exhibit the effects of the present invention, such onium cation is preferably at least one selected from ammonium cations (nitrogen-containing onium cations), sulfonium cations (sulfur-containing onium cations), and phosphorus-containing onium cations (phosphonium cations), and more preferably ammonium cations (nitrogen-containing onium cations).

[0057] The onium cation has, for example, at least one selected from the group consisting of cation structures represented by general formulas (1) to (4). The cation structures represented by general formulas (1) to (3) are cation structures that can be contained in the above-mentioned ammonium cation (nitrogen-containing onium cation). The cation structure represented by general formula (4) is a cation structure that can be contained in the above-mentioned sulfonium cation (sulfur-containing onium cation) and phosphorus-containing onium cation (phosphonium cation).

[0058] In general formula (1), R a represents a hydrocarbon group having 4 to 20 carbon atoms, which may contain a heteroatom; R b and R c are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and may contain a heteroatom. However, when the nitrogen atom contains a double bond, R c There is no.

[0059] In general formula (2), R d represents a hydrocarbon group having 2 to 20 carbon atoms, which may contain a heteroatom; R e , R f , and R gare the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, which may contain a heteroatom.

[0060] In general formula (3), R h represents a hydrocarbon group having 2 to 20 carbon atoms, which may contain a heteroatom; R i , R j , and R k are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, which may contain a heteroatom.

[0061] In general formula (4), Z represents a nitrogen atom, a sulfur atom, or a phosphorus atom, and R l , R m , R n , and R o are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms, which may contain a heteroatom. However, when Z is a sulfur atom, R o There is no.

[0062] Examples of the cation structure represented by general formula (1) include a pyridinium cation structure, a pyrrolidinium cation structure, a piperidinium cation structure, a cation structure having a pyrroline skeleton, and a cation structure having a pyrrole skeleton.

[0063] Specific examples of cationic species having a cationic structure represented by general formula (1) include cations such as 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-octyl-4-methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, and 1,1-dimethylpyrrolidinium cation. pyrrolidinium cation; 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1 pyrrolidinium cations such as 1-ethyl-1-heptylpyrrolidinium cation, 1,1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, and 1,1-dibutylpyrrolidinium cation; 1-propylpiperidinium cation, 1-pentylpiperidinium cation, 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidinium cation, and the like; piperidinium cations such as 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1-propyl-1-butylpiperidinium cation, 1,1-dimethylpiperidinium cation, 1,1-dipropylpiperidinium cation, and 1,1-dibutylpiperidinium cation;Examples include 2-methyl-1-pyrroline cation; 1-ethyl-2-phenylindole cation; 1,2-dimethylindole cation; 1-ethylcarbazole cation; and cations such as these further having at least one group selected from the group consisting of a vinyl group (CH═CH— group) and an allyl group (CH═CH—CH— group).

[0064] Among these, in terms of further exhibiting the effects of the present invention, preferred are pyridinium cations such as 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, and 1-octyl-4-methylpyridinium cation; 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl ... and 1-ethyl-1 pyrrolidinium cations such as 1-hexylpyrrolidinium cation and 1-ethyl-1-heptylpyrrolidinium cation; piperidinium cations such as 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, and 1-propyl-1-butylpiperidinium cation; cations such as these cations further having at least one selected from the group consisting of a vinyl group (CH═CH— group) and an allyl group (CH═CH—CH— group);and more preferably, a 1-hexylpyridinium cation, a 1-ethyl-3-methylpyridinium cation, a 1-butyl-3-methylpyridinium cation, a 1-octyl-4-methylpyridinium cation, a 1-methyl-1-propylpyrrolidinium cation, a 1-methyl-1-propylpiperidinium cation, or a cation further having at least one selected from the group consisting of a vinyl group (CH═CH— group) and an allyl group (CH═CH—CH— group);

[0065] Examples of the cation structure represented by general formula (2) include an imidazolium cation structure, a tetrahydropyrimidinium cation structure, and a dihydropyrimidinium cation structure.

[0066] Specific examples of cationic species having a cationic structure represented by general formula (2) include, for example, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, imidazolium cations such as imidazolium cation, 1-tetradecyl-3-methylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, and 1-hexyl-2,3-dimethylimidazolium cation; 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-trimethyl-1,4 tetrahydropyrimidinium cations such as 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,5-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,3-dimethyl-1,4-dihydropyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium cation, dihydropyrimidinium cations such as 1,2,3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium cation, and 1,2,3,4-tetramethyl-1,6-dihydropyrimidinium cation; and cations which further have at least one selected from the group consisting of a vinyl group (CH═CH— group) and an allyl group (CH═CH—CH— group).

[0067] Among these, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1-tetradecyl-3-methylimidazolium cation, and 1-tetradecyl-3-methylimidazolium cation are preferred, as they can more effectively exhibit the effects of the present invention. imidazolium cations such as 1-ethyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, and cations which further contain at least one selected from the group consisting of a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group). More preferred are 1-ethyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, and cations which further contain at least one selected from the group consisting of a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group).

[0068] Examples of the cation structure represented by general formula (3) include a pyrazolium cation structure and a pyrazolinium cation structure.

[0069] Specific examples of the cationic species having the cationic structure represented by general formula (3) include pyrazolium cations such as a 1-methylpyrazolium cation, a 3-methylpyrazolium cation, a 1-ethyl-2-methylpyrazolinium cation, a 1-ethyl-2,3,5-trimethylpyrazolium cation, a 1-propyl-2,3,5-trimethylpyrazolium cation, and a 1-butyl-2,3,5-trimethylpyrazolium cation; pyrazolinium cations such as a 1-ethyl-2,3,5-trimethylpyrazolinium cation, a 1-propyl-2,3,5-trimethylpyrazolinium cation, and a 1-butyl-2,3,5-trimethylpyrazolinium cation; and cations in which these cations further have at least one selected from the group consisting of a vinyl group (CH═CH— group) and an allyl group (CH═CH—CH— group).

[0070] Examples of the cation structure represented by general formula (4) include a tetraalkylammonium cation structure, a trialkylsulfonium cation structure, a tetraalkylphosphonium cation structure, and structures in which a part of the alkyl groups is substituted with an alkenyl group, an alkoxyl group, or an epoxy group.

[0071] Specific examples of the cation species having the cation structure represented by general formula (4) include, for example, tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, triethylmethylammonium cation, tributylethylammonium cation, trimethylpropylammonium cation, trimethyldecylammonium cation, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N,N-dimethyl-N-ethyl-N-propylammonium cation, N,N-dimethyl-N-ethyl-N-butylammonium cation, N,N-dimethyl-N-ethyl-N-pentylammonium cation, N,N-dimethyl-N-ethyl-N-hexylammonium cation, N,N-dimethyl-N-ethyl-N-heptylammonium cation, N,N-dimethyl-N-ethyl-N-nonylammonium cation, N,N -dimethyl-N,N-dipropylammonium cation, N,N-diethyl-N-propyl-N-butylammonium cation, N,N-dimethyl-N-propyl-N-pentylammonium cation, N,N-dimethyl-N-propyl-N-hexylammonium cation, N,N-dimethyl-N-propyl-N-heptylammonium cation, N,N-dimethyl-N-butyl-N-hexylammonium cation, N,N-diethyl-N-butyl-N-heptylammonium cation, N,N-dimethyl-N-pentyl-N-hexylammonium ammonium cation, N,N-dimethyl-N,N-dihexylammonium cation, trimethylheptylammonium cation, N,N-diethyl-N-methyl-N-propylammonium cation, N,N-diethyl-N-methyl-N-pentylammonium cation, N,N-diethyl-N-methyl-N-heptylammonium cation, N,N-diethyl-N-propyl-N-pentylammonium cation, triethylpropylammonium cation, triethylpentylammonium cation, triethylheptylammonium cation, N,Tetraalkylammonium cations such as N-dipropyl-N-methyl-N-ethylammonium cation, N,N-dipropyl-N-methyl-N-pentylammonium cation, N,N-dipropyl-N-butyl-N-hexylammonium cation, N,N-dipropyl-N,N-dihexylammonium cation, N,N-dibutyl-N-methyl-N-pentylammonium cation, N,N-dibutyl-N-methyl-N-hexylammonium cation, trioctylmethylammonium cation, and N-methyl-N-ethyl-N-propyl-N-pentylammonium cation; trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, and the like. trialkylsulfonium cations such as tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation; and cations in which these cations further have at least one selected from the group consisting of a vinyl group (CH═CH— group) and an allyl group (CH═CH—CH— group).

[0072] As the metal cation, any appropriate metal cation can be used as long as it does not impair the effects of the present invention. In terms of being able to further exhibit the effects of the present invention, such metal cation is preferably an alkali metal cation such as a Li cation, a Na cation, or a K cation.

[0073] The ionic compound may be a compound consisting of the above-described cation species and at least one anion species selected from the group consisting of borate anion and dicyanamide anion.In terms of being able to further exhibit the effects of the present invention, the ionic compound may preferably be a compound consisting of a combination of pyridinium cation and borate anion, a compound consisting of a combination of pyridinium cation and dicyanamide anion, a compound consisting of a combination of imidazolium cation and borate anion, a compound consisting of a combination of imidazolium cation and dicyanamide anion, a compound consisting of a combination of metal cation and borate anion, or a compound consisting of a combination of metal cation and dicyanamide anion, and more preferably Examples of suitable cation exchangers include 1-butyl-3-methylpyridinium bis(oxalate)borate, 1-butyl-3-methylpyridinium dicyanamide, 1-ethyl-3-methylimidazolium bis(oxalate)borate, 1-ethyl-3-methylimidazolium dicyanamide, 1-hexyl-3-methylimidazolium bis(oxalate)borate, 1-hexyl-3-methylimidazolium dicyanamide, 1-octyl-3-methylimidazolium bis(oxalate)borate, 1-octyl-3-methylimidazolium dicyanamide, lithium bis(oxalate)borate, and lithium dicyanamide.

[0074] The ionic compound may be commercially available or synthesized by any suitable method. For example, the ionic liquid may be synthesized by the halide method, hydroxide method, acid ester method, complex formation method, neutralization method, or the like, as described in "Ionic Liquids - The Frontline and Future of Development" (published by CMC Publishing).

[0075] <2-2. Acrylic Pressure-Sensitive Adhesive Composition (A)> One embodiment of the pressure-sensitive adhesive composition is an acrylic pressure-sensitive adhesive composition (A). The acrylic pressure-sensitive adhesive composition (A) contains an acrylic polymer (A) as a base polymer and an ionic compound. As the ionic compound, the ionic compounds described in the section <2-1. Ionic Compounds> can be used.

[0076] <2-2-a. Acrylic Polymer (A)> The acrylic polymer (A) may be a complete polymer or a partial polymer.

[0077] When the acrylic polymer (A) is a complete polymer, the acrylic polymer (A) may be typically an acrylic polymer prepared by solution polymerization using a thermal polymerization initiator. In this case, the acrylic pressure-sensitive adhesive (A) may typically be formed by a crosslinking reaction of an acrylic pressure-sensitive adhesive composition (A) containing the acrylic polymer (A).

[0078] When the acrylic polymer (A) is a partial polymer, the acrylic polymer (A) may typically be an acrylic polymer (typically an acrylic partial polymer) prepared by polymerization (typically partial polymerization) using a photopolymerization initiator. In this case, the acrylic pressure-sensitive adhesive (A) may typically be formed by a photocuring reaction of a photocurable acrylic pressure-sensitive adhesive composition containing the acrylic polymer (A).

[0079] The content of the acrylic polymer (A) in the acrylic pressure-sensitive adhesive composition (A), calculated as solid content, is preferably 1 wt % to 99.999 wt %, optionally 5 wt % to 99.999 wt %, optionally 10 wt % to 99.999 wt %, optionally 20 wt % to 99.999 wt %, optionally 30 wt % to 99.999 wt %, optionally 40 wt % to 99.999 wt %, optionally 50 wt % to 99.999 wt %, optionally 60 wt % to 99.999 wt %, optionally 65 wt % to 99.99 wt %, optionally 70 wt % to 99.9 wt %, optionally 75 wt % to 99.9 wt %, or optionally 78 wt % to 99.9 wt %.

[0080] As the acrylic polymer (A), any appropriate acrylic polymer can be used as long as it does not impair the effects of the present invention.

[0081] The weight-average molecular weight of the acrylic polymer (A) can be any appropriate weight-average molecular weight that can further exhibit the effects of the present invention. When the acrylic polymer (A) is a complete polymer, the weight-average molecular weight of the acrylic polymer (A) is preferably 300,000 to 2,500,000, more preferably 350,000 to 2,000,000, even more preferably 400,000 to 1,800,000, and particularly preferably 500,000 to 1,500,000. When the acrylic polymer (A) is a partial polymer, the weight-average molecular weight of the acrylic polymer (A) can be any appropriate weight-average molecular weight depending on the polymerization conversion rate.

[0082] The acrylic polymer (A) is typically an acrylic polymer formed by polymerization of all or part of raw material monomer components. The acrylic polymer (A) is preferably an acrylic polymer formed by polymerization of all or part of raw material monomer components including (component a) a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms, and (component b) at least one selected from the group consisting of (meth)acrylic acid esters and (meth)acrylic acid having an OH group, in order to further enhance the effects of the present invention. Typically, the monomer components constituting the acrylic polymer (A) preferably include (component a) a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms, and (component b) at least one selected from the group consisting of (meth)acrylic acid esters and (meth)acrylic acid having an OH group.

[0083] The above-mentioned "acrylic polymer formed by polymerization of raw material monomer components" may be an acrylic polymer as a complete polymer formed by polymerization of all of the raw material monomer components, or may be an acrylic polymer as a partial polymer formed by polymerization of a portion of the raw material monomer components.

[0084] The component a and the component b may each independently be one type or two or more types.

[0085] Examples of (meth)acrylic acid alkyl esters (component a) in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms include n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate. Among these, in terms of being able to further exhibit the effects of the present invention, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and n-octyl (meth)acrylate are preferred, and n-butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate are more preferred.

[0086] Examples of the at least one (component b) selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid include (meth)acrylic acid esters having an OH group such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Among these, hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate, and (meth)acrylic acid are preferred, and hydroxyethyl acrylate, hydroxybutyl acrylate, and acrylic acid are more preferred, in terms of being able to further exhibit the effects of the present invention.

[0087] The raw material monomer components may contain a copolymerizable monomer (component c) other than components a and b. The copolymerizable monomer (component c) may be of one type or two or more types. Examples of such copolymerizable monomers (component c) include (meth)acrylic acid alkyl esters having an alkyl group containing 1 to 3 carbon atoms, carboxyl group-containing monomers (excluding (meth)acrylic acid), amide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, cyano group-containing monomers, heterocycle-containing monomers (however, those that also fall under the category of amide group-containing monomers are not included in heterocycle-containing monomers), sulfonic acid group-containing monomers, phosphate group-containing monomers, imide group-containing monomers, isocyanate group-containing monomers, (meth)acrylic acid esters having an alicyclic hydrocarbon group, aromatic ring-containing (meth)acrylates, (meth)acrylic acid alkoxyalkyl esters, vinyl esters, aromatic vinyl compounds, olefins and dienes, vinyl ethers, and vinyl chloride.

[0088] Examples of (meth)acrylic acid alkyl esters in which the alkyl group has 1 to 3 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate.

[0089] Examples of carboxyl group-containing monomers (excluding (meth)acrylic acid) include itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and acid anhydrides thereof (for example, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride).

[0090] The amide group-containing monomer is a compound that contains an amide group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of such amide group-containing monomers include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol-N-propane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, and N-hydroxymethyl(meth)acrylamide. (meth)acrylamide-based monomers such as methyloxyethyl(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, and mercaptoethyl(meth)acrylamide; N-(meth)acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and (meth)acryloylpyrrolidine; and N-vinyl group-containing lactam-based monomers such as N-vinyl-2-pyrrolidone and N-vinyl-ε-caprolactam.

[0091] Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate.

[0092] Examples of epoxy group-containing monomers include glycidyl (meth)acrylate and methylglycidyl (meth)acrylate.

[0093] An example of the cyano group-containing monomer is (meth)acrylonitrile.

[0094] Examples of heterocycle-containing monomers include N-vinylpiperidone, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, vinylpyridine, vinylpyrimidine, and vinyloxazole.

[0095] An example of the sulfonic acid group-containing monomer is sodium vinyl sulfonate.

[0096] An example of the phosphate group-containing monomer is 2-hydroxyethyl acryloyl phosphate.

[0097] Examples of imide group-containing monomers include cyclohexylmaleimide and isopropylmaleimide.

[0098] An example of an isocyanate group-containing monomer is 2-methacryloyloxyethyl isocyanate.

[0099] Examples of the (meth)acrylic acid ester having an alicyclic hydrocarbon group include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate.

[0100] Examples of aromatic ring-containing (meth)acrylates include phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, phenoxybenzyl (meth)acrylate (e.g., m-phenoxybenzyl (meth)acrylate), thiophenoxybenzyl (meth)acrylate, and benzyl benzyl (meth)acrylate.

[0101] Examples of (meth)acrylic acid alkoxyalkyl esters include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate.

[0102] Examples of vinyl esters include vinyl acetate and vinyl propionate.

[0103] Examples of aromatic vinyl compounds include styrene and vinyltoluene.

[0104] Examples of olefins and dienes include ethylene, butadiene, isoprene, and isobutylene.

[0105] Examples of vinyl ethers include vinyl alkyl ethers.

[0106] As the copolymerizable monomer (component c), in terms of being able to further exhibit the effects of the present invention, preferably, the copolymerizable monomer (component c) is a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 1 to 3 carbon atoms, an amide group-containing monomer, a heterocycle-containing monomer, an aromatic ring-containing (meth)acrylate, or an alkoxyalkyl (meth)acrylic acid ester, and more preferably, the copolymerizable monomer is an amide group-containing monomer, a heterocycle-containing monomer, an aromatic ring-containing (meth)acrylate, or an alkoxyalkyl (meth)acrylic acid ester.

[0107] That is, as component c, in order to further exhibit the effects of the present invention, preferably at least one selected from the group consisting of an amide group-containing monomer, an aromatic ring-containing (meth)acrylate, and a (meth)acrylic acid alkoxyalkyl ester is used. Therefore, in order to further exhibit the effects of the present invention, composition (A) preferably contains at least one selected from the group consisting of an amide group-containing monomer, an aromatic ring-containing (meth)acrylate, and a (meth)acrylic acid alkoxyalkyl ester. In other words, the monomer component constituting the acrylic polymer (A) preferably contains at least one selected from the group consisting of an amide group-containing monomer, an aromatic ring-containing (meth)acrylate, and a (meth)acrylic acid alkoxyalkyl ester.

[0108] As the amide group-containing monomer, in terms of being able to more effectively exhibit the effects of the present invention, more preferred examples include N-(meth)acryloyl heterocyclic monomers and N-vinyl group-containing lactam monomers, and particularly preferred examples include N-(meth)acryloylmorpholine and N-vinyl-2-pyrrolidone.

[0109] As the aromatic ring-containing (meth)acrylate, benzyl (meth)acrylate and phenoxybenzyl (meth)acrylate (for example, m-phenoxybenzyl (meth)acrylate) are preferred, as they can further exhibit the effects of the present invention.

[0110] As the (meth)acrylic acid alkoxyalkyl ester, 2-methoxyethyl (meth)acrylate is preferred, as it can more effectively exhibit the effects of the present invention.

[0111] A polyfunctional monomer may also be used as the copolymerizable monomer (component c). In an embodiment in which the acrylic polymer (A) is a partial polymer, the polyfunctional monomer may be treated as a crosslinking agent. Therefore, as described above, in an embodiment in which the acrylic polymer (A) is a partial polymer, the polyfunctional monomer is not considered to be included in the raw monomer components. A polyfunctional monomer refers to a monomer having two or more ethylenically unsaturated groups per molecule, or a monomer having one or more ethylenically unsaturated groups and one or more polymerizable functional groups, such as epoxy groups, aziridine groups, oxazoline groups, hydrazine groups, or methylol groups, per molecule. Any appropriate ethylenically unsaturated group may be used as the ethylenically unsaturated group as long as it does not impair the effects of the present invention. Examples of such ethylenically unsaturated groups include radically polymerizable functional groups such as vinyl groups, propenyl groups, isopropenyl groups, vinyl ether groups (vinyloxy groups), and allyl ether groups (allyloxy groups).

[0112] Examples of polyfunctional monomers include 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol diacrylate (NDDA), 1,12-dodecanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, and pentaerythritol di(meth)acrylate. Examples of the acrylate include polyfunctional acrylates (e.g., ester compounds of polyhydric alcohols and (meth)acrylic acid) such as tetritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; allyl (meth)acrylate; vinyl (meth)acrylate; divinylbenzene; epoxy acrylate; polyester acrylate; urethane acrylate; butyl di(meth)acrylate; and hexyl di(meth)acrylate.

[0113] The content of the (meth)acrylic acid alkyl ester (component a) in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms in the total amount of the raw material monomer components is, in order to further exhibit the effects of the present invention, for example, 10% by weight or more, preferably 20% by weight or more, more preferably 20% by weight to 99% by weight, even more preferably 20% by weight to 90% by weight, particularly preferably 22% by weight to 85% by weight, and most preferably 25% by weight to 82% by weight, relative to the total amount of the raw material monomer components. In one embodiment, the content of the (meth)acrylic acid alkyl ester (component a) in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms in the total amount of the raw material monomer components is, for example, 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight to 99% by weight, and particularly preferably 60% by weight to 98% by weight. In one embodiment, the content of the (meth)acrylic acid alkyl ester (component a) in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms in the total amount of the raw material monomer components is more preferably 70% by weight to 97% by weight, particularly preferably 80% by weight to 97% by weight, and most preferably 88% by weight to 96% by weight.

[0114] The content of at least one selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid (component b) in the total amount of raw monomer components is, in order to further exhibit the effects of the present invention, for example, 0.1 wt % or more, preferably 0.1 to 20 wt %, more preferably 0.2 to 10 wt %, even more preferably 0.2 to 5 wt %, and particularly preferably 0.3 to 1 wt %. In one embodiment, the content of at least one selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid (component b) in the total amount of raw monomer components is, for example, 0.1 wt % or more, preferably 0.2 to 30 wt %, more preferably 0.3 to 20 wt %, even more preferably 0.4 to 15 wt %, and particularly preferably 0.5 to 12 wt %.

[0115] The content of the copolymerizable monomer (component c) in the total amount of the raw material monomer components is, for example, 0.1% by weight or more, preferably 5% to 90% by weight, more preferably 10% to 80% by weight, even more preferably 13% to 75% by weight, and particularly preferably 15% to 70% by weight, relative to the total amount of the raw material monomer components, in order to further exhibit the effects of the present invention. In one embodiment, the content of the copolymerizable monomer (component c) in the total amount of the raw material monomer components is, for example, 0% to 80% by weight, preferably 0% to 70% by weight, more preferably 0% to 60% by weight, even more preferably 0% to 50% by weight, particularly preferably 0% to 40% by weight, and most preferably 0% to 30% by weight.

[0116] In one embodiment, the raw material monomer components may contain, as the copolymerizable monomer (component c), the aforementioned (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 1 to 3 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, or propyl (meth)acrylate. When the raw material monomer components contain such a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 1 to 3 carbon atoms, the content of such a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester moiety has 1 to 3 carbon atoms in the total amount of the raw material monomer components is preferably 0.1% by weight or more, more preferably 0.1 to 40% by weight, even more preferably 0.5 to 30% by weight, and particularly preferably 1 to 20% by weight, relative to the total amount of the raw material monomer components.

[0117] In one embodiment, the raw material monomer component includes, as the copolymerizable monomer (component c), the above-mentioned (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol-N-propane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-hydroxy ...

[0049] The copolymer may contain an amide group-containing monomer, such as (meth)acrylamide-based monomers such as hydroxyethyl(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, and mercaptoethyl(meth)acrylamide; N-(meth)acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and (meth)acryloylpyrrolidine; and N-vinyl group-containing lactam-based monomers such as N-vinyl-2-pyrrolidone and N-vinyl-ε-caprolactam. When the raw material monomer components contain such an amide group-containing monomer, the content of such an amide group-containing monomer in the total amount of the raw material monomer components is preferably 0.1% by weight or more, more preferably 0.1% by weight to 30% by weight, even more preferably 0.5% by weight to 25% by weight, still more preferably 1% by weight to 20% by weight, particularly preferably 1% by weight to 10% by weight, and most preferably 1% by weight to 5% by weight, based on the total amount of the raw material monomer components.

[0118] In one embodiment, the raw material monomer components may contain, as a copolymerizable monomer (component c), the aforementioned aromatic ring-containing (meth)acrylates such as phenyl(meth)acrylate, phenoxyethyl(meth)acrylate, benzyl(meth)acrylate, phenoxybenzyl(meth)acrylate (e.g., m-phenoxybenzyl(meth)acrylate), thiophenoxybenzyl(meth)acrylate, and benzylbenzyl(meth)acrylate. When the raw material monomer components contain such aromatic ring-containing (meth)acrylates, the content of such aromatic ring-containing (meth)acrylates in the total amount of the raw material monomer components is preferably 0.1% by weight or more, more preferably 1 to 30% by weight, even more preferably 5 to 25% by weight, and particularly preferably 10 to 20% by weight, relative to the total amount of the raw material monomer components.

[0119] In one embodiment, the raw material monomer component may contain, as a copolymerizable monomer (component c), the above-mentioned (meth)acrylic acid alkoxyalkyl esters such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate. When the raw material monomer components contain such an alkoxyalkyl (meth)acrylate ester, the content of such an alkoxyalkyl (meth)acrylate ester in the total amount of the raw material monomer components is preferably 0.1% by weight or more, more preferably 0.1 to 70% by weight, even more preferably 0.1 to 65% by weight, still more preferably 0.1 to 60% by weight, particularly preferably 0.2 to 55% by weight, and most preferably 0.3 to 55% by weight, based on the total amount of the raw material monomer components.

[0120] In terms of being able to further exert the effects of the present invention, one preferred embodiment of the raw material monomer components comprises a (meth)acrylic acid alkyl ester (component a) in which the alkyl group in the alkyl ester moiety has 4 to 12 carbon atoms, at least one member selected from the group consisting of a (meth)acrylic acid ester having an OH group and (meth)acrylic acid (component b), and at least one member selected from the group consisting of an amide group-containing monomer, an aromatic ring-containing (meth)acrylate, and an alkoxyalkyl (meth)acrylic acid ester.

[0121] The composition containing all or part of the raw material monomer components to be subjected to the polymerization reaction to obtain the acrylic polymer (A) may contain any appropriate other components as long as the effects of the present invention are not impaired. Examples of such other components include a polymerization initiator, a chain transfer agent, and a solvent. The content of these other components may be any appropriate content as long as the effects of the present invention are not impaired.

[0122] The polymerization initiator may be a thermal polymerization initiator, a photopolymerization initiator (photoinitiator), or the like, depending on the type of polymerization reaction. Only one type of polymerization initiator may be used, or two or more types may be used.

[0123] A thermal polymerization initiator is preferably employed when obtaining the acrylic polymer (A) by solution polymerization. Examples of such thermal polymerization initiators include azo polymerization initiators, peroxide polymerization initiators (e.g., dibenzoyl peroxide, tert-butyl permaleate), and redox polymerization initiators. Among these thermal polymerization initiators, the azo polymerization initiators disclosed in JP-A-2002-69411 are particularly preferred. Such azo polymerization initiators are preferred because decomposition products of the polymerization initiator are less likely to remain in the acrylic polymer as moieties that cause outgassing upon heating. Examples of azo polymerization initiators include 2,2'-azobisisobutyronitrile (hereinafter sometimes referred to as AIBN), 2,2'-azobis-2-methylbutyronitrile (hereinafter sometimes referred to as AMBN), 2,2'-azobis(2-methylpropionate)dimethyl, and 4,4'-azobis-4-cyanovaleric acid.

[0124] The photopolymerization initiator can be preferably used when obtaining the acrylic polymer (A) by active energy ray polymerization (typically, photopolymerization). Examples of the photopolymerization initiator include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and acylphosphine oxide-based photopolymerization initiators. Specific examples of these photopolymerization initiators that can be used include known photopolymerization initiators.

[0125] Specific examples of the benzoin ether-based photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethan-1-one (a commercially available product is, for example, the trade name "OMNIRAD651" manufactured by IGM Resins B.V.), and anisole methyl ether.

[0126] Specific examples of the acetophenone-based photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone (a commercially available product is, for example, the trade name "OMNIRAD184", manufactured by IGM Resins B.V.), 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (a commercially available product is, for example, the trade name "OMNIRAD2959", manufactured by IGM Resins B.V.), 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and methoxyacetophenone.

[0127] Specific examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)-phenyl]-2-hydroxy-2-methylpropan-1-one, and the like.

[0128] Specific examples of aromatic sulfonyl chloride photopolymerization initiators include 2-naphthalenesulfonyl chloride.

[0129] Specific examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime.

[0130] Specific examples of benzoin-based photopolymerization initiators include benzoin.

[0131] Specific examples of benzyl-based photopolymerization initiators include benzyl.

[0132] Specific examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone.

[0133] Specific examples of the ketal-based photopolymerization initiator include benzyl dimethyl ketal.

[0134] Specific examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0135] Specific examples of the acylphosphine photopolymerization initiator include bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-n-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-(1-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-(1-methylpropan-1-yl)phosphine oxide, and bis(2,6-dimethoxybenzoyl)phenylphosphine oxide. bis(2,6-dimethoxybenzoyl)cyclohexylphosphine oxide, bis(2,6-dimethoxybenzoyl)octylphosphine oxide, bis(2-methoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2-methoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide, bis(2,6-diethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,6-diethoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide bis(2,6-dibutoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4-dimethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)(2,4-dipentoxyphenyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)benzylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2 -phenylethylphosphine oxide, bis(2,6-dimethoxybenzoyl)benzylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide, bis(2,4,bis(2,4,6-trimethylbenzoyl)-2-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,3,5,6-tetramethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)isobutylphosphine oxide, 2,6-dimethythoxybenzoyl-2,4,6-trimethylbenzoyl-n-butylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dibutoxyphenylphosphine oxide, 1,10-bis[bis(2,4,6-trimethylbenzoyl)phosphine oxide]decane, tri(2-methylbenzoyl)phosphine oxide, and the like.

[0136] The amount of the polymerization initiator used may be any appropriate amount as long as the effects of the present invention are not impaired. The amount of the polymerization initiator used is, for example, preferably 0.01 to 15% by weight based on the amount of all or a part of the raw material monomer components used in the polymerization reaction to obtain the acrylic polymer (A).

[0137] As the chain transfer agent, known chain transfer agents can be used. The chain transfer agent may be one type or two or more types.

[0138] The amount of the chain transfer agent used may be any appropriate amount as long as the effects of the present invention are not impaired. For example, the amount used is preferably 0.01 to 15% by weight based on the amount of all or a part of the raw material monomer components used in the polymerization reaction to obtain the acrylic polymer (A).

[0139] Any appropriate solvent may be used as the solvent as long as it does not impair the effects of the present invention. Examples of such solvents include organic solvents such as esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and ketones such as methyl ethyl ketone and methyl isobutyl ketone. Only one type of solvent may be used, or two or more types may be used. Any appropriate amount of solvent may be used as long as it does not impair the effects of the present invention.

[0140] The acrylic polymer (A) can be produced by any appropriate polymerization method as long as the effects of the present invention are not impaired. Examples of polymerization methods that can be used to polymerize the acrylic polymer (A) include solution polymerization, emulsion polymerization, bulk polymerization, and active energy ray polymerization by irradiation with ultraviolet rays or the like, and representative examples are solution polymerization and photopolymerization.

[0141] As a method for supplying the raw material monomer components when carrying out solution polymerization, a batch charging method in which the entire amount of the raw material monomer components is supplied at once, a continuous supply (dropping) method, a divided supply (dropping) method, etc. can be appropriately adopted. The polymerization temperature can be appropriately selected depending on the raw material monomer components, the type of solvent, the type of polymerization initiator used, etc., and is preferably 20°C to 160°C, more preferably 30°C to 140°C, even more preferably 40°C to 120°C, and particularly preferably 50°C to 100°C. The polymerization time can be appropriately selected depending on the raw material monomer components, the type of solvent, the type of polymerization initiator used, etc., and is preferably 1 hour to 24 hours, more preferably 1 hour to 12 hours.

[0142] Photopolymerization can be carried out by any appropriate method as long as it does not impair the effects of the present invention. Photopolymerization can be carried out, for example, by irradiating a composition containing all or part of the raw material monomer components to be subjected to a polymerization reaction to obtain the acrylic polymer (A) with ultraviolet light. To obtain the acrylic polymer (A) as a partial polymer, for example, the ultraviolet light irradiation can be appropriately adjusted.

[0143] <2-2-b. Crosslinking agent> The acrylic pressure-sensitive adhesive composition (A) may contain a crosslinking agent. Use of a crosslinking agent can further enhance the effects of the present invention. The crosslinking agent may be of only one type, or may be of two or more types.

[0144] Examples of crosslinking agents include polyfunctional isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, and amine-based crosslinking agents. Among these, at least one crosslinking agent selected from the group consisting of polyfunctional isocyanate-based crosslinking agents, epoxy-based crosslinking agents, and peroxide-based crosslinking agents is preferred, as it can further enhance the effects of the present invention. Such crosslinking agents may be used alone or in combination of two or more types. The crosslinking agent according to this embodiment is suitable when the acrylic polymer (A) is a complete polymer, particularly when the acrylic polymer (A) is an acrylic polymer prepared by solution polymerization using a thermal polymerization initiator, and the acrylic pressure-sensitive adhesive (A) is formed by a crosslinking reaction of an acrylic pressure-sensitive adhesive composition (A) containing the acrylic polymer (A). Of course, the crosslinking agent according to this embodiment may be used when the acrylic polymer (A) is a partial polymer.

[0145] As the polyfunctional isocyanate-based crosslinking agent, a compound having two or more isocyanate groups (including isocyanate-regenerating polar groups in which the isocyanate group is temporarily protected by a blocking agent or oligomerization, etc.) in one molecule can be used. Specific examples of the polyfunctional isocyanate crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; aromatic diisocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate and polymethylene polyphenyl isocyanate; trimethylolpropane / tolylene diisocyanate trimer adduct (for example, manufactured by Mitsui Chemicals, Inc., trade name: Takenate D101E), trimethylolpropane / hexamethylene diisocyanate trimer adduct (for example, manufactured by Tosoh Corporation, trade name: Coronate HL), and isocyanurate of hexamethylene diisocyanate (for example, Examples of suitable polyisocyanates include isocyanate adducts such as those manufactured by Tosoh Corporation under the trade name of Coronate HX; trimethylolpropane adducts of xylylene diisocyanate (for example, Mitsui Chemicals, Inc., trade name: Takenate D110N), trimethylolpropane adducts of xylylene diisocyanate (for example, Mitsui Chemicals, Inc., trade name: Takenate D120N), trimethylolpropane adducts of isophorone diisocyanate (for example, Mitsui Chemicals, Inc., trade name: Takenate D140N), and trimethylolpropane adducts of hexamethylene diisocyanate (for example, Mitsui Chemicals, Inc., trade name: Takenate D160N); polyether polyisocyanates, polyester polyisocyanates, and adducts of these with various polyols; and polyisocyanates multifunctionalized with isocyanurate bonds, biuret bonds, allophanate bonds, etc.

[0146] Examples of epoxy crosslinking agents (polyfunctional epoxy compounds) include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, and methyl ... Examples of the epoxy crosslinking agent include diglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Examples of the epoxy crosslinking agent include commercially available products such as "Tetrad C" (manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0147] Examples of peroxide-based crosslinking agents include dibenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butyl hydroperoxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxin)hexyne-3, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-mono(t-butylperoxy)hexane, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxy Examples of commercially available peroxides include xyleneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide, t-butylperoxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, t-butylperoxy-2-ethylhexyl carbonate, t-amylperoxyisopropyl carbonate, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-hexanoate, t-butyl peroxypivalate, and t-hexyl peroxypivalate. Examples of commercially available peroxides include the "Niper BMT" series and "Niper BW" series manufactured by NOF Corporation.

[0148] Another embodiment of the crosslinking agent includes the polyfunctional monomers described above in Section <2-2-a. Acrylic Polymer (A)>. Such crosslinking agents may be used alone or in combination of two or more types. The crosslinking agent according to this embodiment is suitable when the acrylic polymer (A) is a partial polymer, and is particularly suitable when the acrylic polymer (A) is an acrylic polymer (typically an acrylic partial polymer) prepared by polymerization (typically partial polymerization) using a photopolymerization initiator, and the acrylic pressure-sensitive adhesive (A) is formed by a photocuring reaction of a photocurable acrylic pressure-sensitive adhesive composition containing the acrylic polymer (A). Of course, the crosslinking agent according to this embodiment may also be used when the acrylic polymer (A) is a complete polymer.

[0149] The content of the crosslinking agent in the acrylic pressure-sensitive adhesive composition (A) may be any appropriate content as long as it does not impair the effects of the present invention. In terms of further exhibiting the effects of the present invention, the content is preferably 0.001% by weight to 20 parts by weight, or may be 0.005 parts by weight to 20 parts by weight, or 0.01 parts by weight to 10 parts by weight, or 0.05 parts by weight to 5 parts by weight, or 0.05 parts by weight to 3 parts by weight, or 0.05 parts by weight to 1 part by weight, or 0.05 parts by weight to 0.5 parts by weight, or 0.05 parts by weight to 0.25 parts by weight, relative to 100 parts by weight of the base polymer.

[0150] <2-2-c. Acrylic Oligomer> The acrylic pressure-sensitive adhesive composition (A) may contain an acrylic oligomer. The acrylic oligomer may be one type only, or two or more types may be used.

[0151] The content of the acrylic oligomer in the acrylic pressure-sensitive adhesive composition (A) is preferably 0 to 50 parts by weight, more preferably 0 to 40 parts by weight, and even more preferably 0 to 30 parts by weight, relative to 100 parts by weight of the base polymer.

[0152] The weight average molecular weight of the acrylic oligomer is preferably 1,000 to 30,000, more preferably 1,000 to 20,000, still more preferably 1,500 to 10,000, and particularly preferably 2,000 to 8,000. The weight average molecular weight (Mw) can be determined in polystyrene equivalent terms by the GPC method.

[0153] The acrylic oligomer is preferably an acrylic oligomer obtained from a monomer component containing, as an essential component, a (meth)acrylic acid ester having a cyclic structure in the molecule.

[0154] The (meth)acrylic acid ester having a cyclic structure in the molecule may be of one type only, or of two or more types.

[0155] Specific examples of the (meth)acrylic acid ester having a cyclic structure in the molecule include (meth)acrylic acid cycloalkyl esters such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate; (meth)acrylic acid esters having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth)acrylate; dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate; Examples of (meth)acrylic acid esters include (meth)acrylic acid esters having three or more aliphatic hydrocarbon rings, such as 2-ethyl-2-adamantyl (meth)acrylate; and (meth)acrylic acid esters having an aromatic ring, such as (meth)acrylic acid aryl esters, such as phenyl (meth)acrylate; (meth)acrylic acid aryloxyalkyl esters, such as phenoxyethyl (meth)acrylate; and (meth)acrylic acid arylalkyl esters, such as benzyl (meth)acrylate; and from the viewpoint of being able to further exhibit the effects of the present invention, preferred are cyclohexyl acrylate, cyclohexyl methacrylate, dicyclopentanyl acrylate, and dicyclopentanyl methacrylate.

[0156] The content of the (meth)acrylic acid ester having a cyclic structure in the molecule relative to the total amount of monomer components constituting the acrylic oligomer is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 99% by weight, even more preferably 80% by weight to 98% by weight, particularly preferably 90% by weight to 97% by weight, and most preferably 92% by weight to 97% by weight.

[0157] The monomer components constituting the acrylic oligomer may contain a carboxyl group-containing monomer. Examples of such carboxyl group-containing monomers include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and acid anhydrides thereof (e.g., acid anhydride group-containing monomers such as maleic anhydride and itanoic anhydride). Such carboxyl group-containing monomers may be used alone or in combination of two or more.

[0158] The content of the carboxyl group-containing monomer relative to the total amount of monomer components constituting the acrylic oligomer is preferably 0 to 20% by weight, more preferably 1 to 10% by weight, even more preferably 2 to 9% by weight, particularly preferably 3 to 8% by weight, and most preferably 4 to 7% by weight.

[0159] The monomer component constituting the acrylic oligomer may contain other monomers, and such other monomers may be of only one type or of two or more types.

[0160] The content ratio of the other monomers relative to the total amount of the monomer components constituting the acrylic oligomer is preferably 0 to 50% by weight, more preferably 0 to 30% by weight, even more preferably 0 to 20% by weight, particularly preferably 0 to 10% by weight, and most preferably 0 to 5% by weight.

[0161] Examples of other monomers include (meth)acrylic acids such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, and isodecyl (meth)acrylate. alkyl esters; epoxy group-containing acrylic monomers such as glycidyl (meth)acrylate and methyl glycidyl (meth)acrylate; vinyl ester monomers such as vinyl acetate and vinyl propionate; hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate and hydroxybutyl (meth)acrylate; alkoxyalkyl (meth)acrylate monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; olefin monomers such as ethylene, propylene, isoprene and butadiene; and vinyl ether monomers such as vinyl ether.

[0162] Examples of other monomers include polyfunctional monomers such as hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinylbenzene, butyl di(meth)acrylate, and hexyl di(meth)acrylate.

[0163] Examples of other monomers include nitrogen atom-containing monomers (for example, aminoalkyl (meth)acrylate monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; (N-substituted) amide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, and N-hydroxy(meth)acrylamide; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; and isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate).

[0164] The acrylic oligomer is preferably formed by polymerization from a composition containing a monomer component essentially consisting of a (meth)acrylic acid ester having a cyclic structure in the molecule, in order to further enhance the effects of the present invention. Such a composition may contain any other appropriate components in addition to the monomer component. Examples of such other components include polymerization initiators, chain transfer agents, solvents, other polymer components, crosslinking accelerators, crosslinking catalysts, silane coupling agents, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), antioxidants, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foils, UV absorbers, antioxidants, light stabilizers, plasticizers, softeners, surfactants, antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, and catalysts.

[0165] The explanations in the section <2-2-a. Acrylic polymer (A)> can be used for the polymerization initiator, chain transfer agent, and solvent.

[0166] The acrylic oligomer can be prepared by any appropriate polymerization method as long as the effects of the present invention are not impaired. Polymerization methods that can be used to polymerize the acrylic oligomer include, for example, solution polymerization, emulsion polymerization, bulk polymerization, and active energy ray polymerization by irradiation with ultraviolet light or the like. Representative examples include solution polymerization and active energy ray polymerization, with solution polymerization being preferred. As a monomer supply method for solution polymerization, a batch charging method in which the entire amount of the monomer components is supplied at once, a continuous supply (dropping) method, a divided supply (dropping) method, or the like can be appropriately employed. The polymerization temperature can be appropriately selected depending on the type of monomer and solvent used, the type of polymerization initiator, and the like, and is preferably 20°C to 160°C, more preferably 30°C to 140°C, even more preferably 40°C to 120°C, and particularly preferably 50°C to 100°C.

[0167] The amount of the polymerization initiator used may be any appropriate amount as long as the effects of the present invention are not impaired. The amount of the polymerization initiator used is, for example, preferably 0.01 to 15% by weight based on the total amount of the monomer components constituting the acrylic oligomer.

[0168] The amount of the chain transfer agent used may be any appropriate amount as long as it does not impair the effects of the present invention, and is, for example, preferably 0.01 to 15% by weight based on the total amount of the monomer components constituting the acrylic oligomer.

[0169] <2-2-d. Other Components> The acrylic pressure-sensitive adhesive composition (A) may contain any appropriate other components as long as the effects of the present invention are not impaired. Examples of such other components include other polymer components, crosslinking accelerators, crosslinking retarders, crosslinking catalysts, silane coupling agents, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), fatty acid esters, silicone additives, antioxidants, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foil-like materials, UV absorbers, antioxidants, light stabilizers, plasticizers, softeners, surfactants, antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, and catalysts.

[0170] The content of the other components in the acrylic pressure-sensitive adhesive composition (A) is preferably 0 to 30 parts by weight, more preferably 0 to 20 parts by weight, and even more preferably 0 to 10 parts by weight, relative to 100 parts by weight of the base polymer.

[0171] <<2-3. Acrylic Pressure-Sensitive Adhesive Composition (B)>> One embodiment of the pressure-sensitive adhesive composition is an acrylic pressure-sensitive adhesive composition (B). The acrylic pressure-sensitive adhesive composition (B) contains an acrylic polymer (B) as a base polymer and an ionic compound. As the ionic compound, the ionic compounds described in the section <<2-1. Ionic Compounds>> can be used.

[0172] <2-3-a. Acrylic polymer (B)> The content of the acrylic polymer (B) in the acrylic pressure-sensitive adhesive composition (B) is preferably 50 wt % to 99.999 wt %, more preferably 60 wt % to 99.99 wt %, even more preferably 65 wt % to 99.9 wt %, particularly preferably 70 wt % to 99 wt %, and most preferably 72 wt % to 95 wt %, calculated as solid content.

[0173] Any appropriate acrylic polymer can be used as the acrylic polymer (B) as long as it does not impair the effects of the present invention. For example, the acrylic polymer (A) described in the section <2-2-a. Acrylic polymer (A)> can be used as the acrylic polymer (B).

[0174] <2-3-b. Crosslinking agent> The acrylic pressure-sensitive adhesive composition (B) may contain a crosslinking agent. Use of a crosslinking agent can further enhance the effects of the present invention. The crosslinking agent may be of only one type, or may be of two or more types.

[0175] As the crosslinking agent, the crosslinking agents explained in the section <2-2-b. Crosslinking agent> can be used.

[0176] The content of the crosslinking agent in the acrylic pressure-sensitive adhesive composition (B) may be any appropriate content ratio as long as the effects of the present invention are not impaired. In terms of further exhibiting the effects of the present invention, the content ratio is preferably 0.005 to 20 parts by weight, more preferably 0.01 to 10 parts by weight, even more preferably 0.01 to 5 parts by weight, particularly preferably 0.05 to 4 parts by weight, and most preferably 0.08 to 3 parts by weight, relative to 100 parts by weight of the base polymer (100 parts by weight of the solids content of the acrylic polymer (B)).

[0177] <2-3-c. Crosslinking catalyst> The acrylic pressure-sensitive adhesive composition (B) may contain a crosslinking catalyst. The crosslinking catalyst may be one type only, or two or more types may be used.

[0178] Any appropriate crosslinking catalyst can be used as long as it does not impair the effects of the present invention, including, for example, metal-based crosslinking catalysts such as tetra-n-butyl titanate, tetraisopropyl titanate, zirconium tetraacetylacetonate, iron diacetylacetonate, butyltin oxide, and dioctyltin dilaurate.

[0179] The content of the crosslinking catalyst in the acrylic pressure-sensitive adhesive composition (B) may be any appropriate content within a range that does not impair the effects of the present invention. In order to further exhibit the effects of the present invention, the content is preferably 0.0001 to 1 part by weight relative to 100 parts by weight of the base polymer (100 parts by weight of the solid content of the acrylic polymer (B)).

[0180] <2-3-d. Photocuring agent> The acrylic pressure-sensitive adhesive composition (B) may contain a photocuring agent. The photocuring agent may be a single type or two or more types.

[0181] Examples of the photocuring agent include a photocurable monomer and a photocurable oligomer. The photocuring agent is preferably a compound having two or more ethylenically unsaturated bonds in one molecule.

[0182] The photocuring agent is preferably a compound that is compatible with the base polymer, and in this respect, a compound that is liquid at room temperature is preferred. Furthermore, the compatibility between the base polymer and the photocuring agent is also influenced by the molecular weight of the compound, and the smaller the molecular weight, the higher the compatibility with the base polymer. Therefore, the molecular weight of the photocuring agent is preferably 1,500 or less, more preferably 1,000 or less.

[0183] The photocuring agent is preferably a polyfunctional (meth)acrylate. Examples of the polyfunctional (meth)acrylate include polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, bisphenol A ethylene oxide modified di(meth)acrylate, bisphenol A propylene oxide modified di(meth)acrylate, alkanediol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol di(meth)acrylate. acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, dipentaerythritol hexa(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerin di(meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, butadiene (meth)acrylate, isoprene (meth)acrylate.

[0184] The functional group equivalent (g / eq) of the photocuring agent is preferably 100 to 500, more preferably 130 to 450, still more preferably 150 to 450, and particularly preferably 180 to 450.

[0185] The content of the photocuring agent in the acrylic pressure-sensitive adhesive composition (B) may be any appropriate content ratio as long as the effects of the present invention are not impaired. In terms of further exhibiting the effects of the present invention, the content ratio is preferably 1 to 100 parts by weight, more preferably 2 to 70 parts by weight, even more preferably 3 to 50 parts by weight, particularly preferably 4 to 40 parts by weight, and most preferably 5 to 35 parts by weight, relative to 100 parts by weight of the base polymer (100 parts by weight of the solid content of the acrylic polymer (B)).

[0186] <2-3-e. Photopolymerization initiator> The acrylic pressure-sensitive adhesive composition (B) may contain a photopolymerization initiator. The photopolymerization initiator may be one type or two or more types.

[0187] As the photopolymerization initiator, any appropriate photopolymerization initiator can be used as long as it does not impair the effects of the present invention. Examples of such photopolymerization initiators include the photopolymerization initiators described in the section <2-2-a. Acrylic polymer (A)>.

[0188] The content of the photopolymerization initiator in the acrylic pressure-sensitive adhesive composition (B) may be any appropriate content ratio within a range that does not impair the effects of the present invention. In order to further exhibit the effects of the present invention, the content ratio is preferably 0.02 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, relative to 100 parts by weight of the base polymer (100 parts by weight of the solid content of the acrylic polymer (B)).

[0189] <2-3-f. Other Components> The acrylic pressure-sensitive adhesive composition (B) may contain any appropriate other components as long as the effects of the present invention are not impaired. As such other components, the other components described in the section <2-2-d. Other Components> can be used.

[0190] The content ratio of other components in the acrylic pressure-sensitive adhesive composition (B) is preferably 0 to 40 parts by weight, more preferably 0 to 30 parts by weight, and even more preferably 0 to 20 parts by weight, relative to 100 parts by weight of the base polymer (100 parts by weight of the solid content of the acrylic polymer (B)).

[0191] <<2-4. Urethane-Based Pressure-Sensitive Adhesive Composition (C)>> One embodiment of the pressure-sensitive adhesive composition is a urethane-based pressure-sensitive adhesive composition (C). The urethane-based pressure-sensitive adhesive composition (C) contains a polyol as a base polymer and an ionic compound. As the ionic compound, the ionic compounds described in the section <<2-1. Ionic Compounds>> can be used.

[0192] <2-4-a. Polyol> As the polyol used as the base polymer, any suitable polyol can be used as long as it can be directly reacted with a polyfunctional isocyanate compound to produce a "one-shot type urethane polymer" within the scope of the present invention. Examples of such polyols include the polyols used as base polymers described in JP-A-2023-167113, and the description related to the polyol used as the base polymer described in JP-A-2023-167113 can be used as a description of the polyol in this specification.

[0193] <2-4-b. Polyfunctional isocyanate compound> The urethane-based pressure-sensitive adhesive composition (C) may contain a polyfunctional isocyanate compound. Use of a polyfunctional isocyanate compound can further enhance the effects of the present invention. The polyfunctional isocyanate compound may be one type or two or more types.

[0194] As the polyfunctional isocyanate compound, any suitable polyfunctional isocyanate compound can be used as long as it is a polyfunctional isocyanate compound that can be directly reacted with a polyol to produce a "one-shot type urethane polymer" within the scope of the present invention. Examples of such polyfunctional isocyanate compounds include the polyfunctional isocyanate compounds described in JP 2023-167113 A, and the description related to the polyfunctional isocyanate compound described in JP 2023-167113 A can be used as a description of the polyfunctional isocyanate compound in this specification.

[0195] <2-4-c. Other Components> The urethane-based pressure-sensitive adhesive composition (C) may contain any appropriate other component within the scope of not impairing the effects of the present invention. As such other component, the other components described in the section <2-2-d. Other Components> can be used.

[0196] The content ratio of other components in the urethane-based pressure-sensitive adhesive composition (C) is preferably 0 to 40 parts by weight, more preferably 0 to 30 parts by weight, and even more preferably 0 to 20 parts by weight, relative to the polyol (100 parts by weight) as the base polymer.

[0197] <2-5. Urethane-Based Pressure-Sensitive Adhesive Composition (D)> One embodiment of the pressure-sensitive adhesive composition is a urethane-based pressure-sensitive adhesive composition (D). The urethane-based pressure-sensitive adhesive composition (D) contains a urethane prepolymer as a base polymer and an ionic compound. As the ionic compound, the ionic compounds described in the section <2-1. Ionic Compounds> can be used.

[0198] <2-5-a. Urethane prepolymer> As the urethane prepolymer as the base polymer, any appropriate urethane prepolymer can be used as long as it is a urethane prepolymer that can be reacted with a polyfunctional isocyanate compound to produce a "prepolymer-type urethane polymer" within the scope that does not impair the effects of the present invention. Examples of such urethane prepolymers include the urethane prepolymers used as base polymers described in JP 2023-167112 A, and the description related to the urethane prepolymer used as the base polymer described in JP 2023-167112 A can be used as a description of the urethane prepolymer in this specification.

[0199] <2-5-b. Polyfunctional isocyanate compound> The urethane-based pressure-sensitive adhesive composition (D) may contain a polyfunctional isocyanate compound. Use of a polyfunctional isocyanate compound can further enhance the effects of the present invention. The polyfunctional isocyanate compound may be one type or two or more types.

[0200] As the polyfunctional isocyanate compound, any suitable polyfunctional isocyanate compound can be used as long as it is a polyfunctional isocyanate compound that can be reacted with a urethane prepolymer to produce a "prepolymer-type urethane polymer" within the scope of the present invention. Examples of such polyfunctional isocyanate compounds include the polyfunctional isocyanate compounds described in JP 2023-167112 A, and the description related to the polyfunctional isocyanate compound described in JP 2023-167112 A can be used as a description of the polyfunctional isocyanate compound in this specification.

[0201] <2-5-c. Other Components> The urethane-based pressure-sensitive adhesive composition (D) may contain any appropriate other component within the scope of not impairing the effects of the present invention. As such other component, the other components described in the section <2-2-d. Other Components> can be used.

[0202] The content ratio of other components in the urethane-based pressure-sensitive adhesive composition (D) is preferably 0 to 40 parts by weight, more preferably 0 to 30 parts by weight, and even more preferably 0 to 20 parts by weight, relative to the polyol (100 parts by weight) as the base polymer.

[0203] 3. Polarizing Film The polarizing film includes at least a polarizer and a transparent protective film. In the polarizing film shown in FIG. 1 , the polarizer may be laminated directly to the pressure-sensitive adhesive layer 20, or may be laminated via the transparent protective film.

[0204] The polarizing film may typically have a transparent protective film on one or both sides of the polarizer. When a transparent protective film is provided on one side of the polarizer, the transparent protective film may be located on the viewing side of the polarizer or on the side opposite to the viewing side.

[0205] Any appropriate polarizer can be used as the polarizer as long as it does not impair the effects of the present invention. Examples of such polarizers include polarizers made of a resin film. The resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

[0206] A specific example of a polarizer composed of a single-layer resin film is a PVA-based resin film that has been subjected to a dyeing treatment with iodine and a stretching treatment (typically, uniaxial stretching). Dyeing with iodine is performed, for example, by immersing the PVA-based resin film in an iodine aqueous solution. The stretching ratio is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or while dyeing. Alternatively, the film may be dyed after stretching. If necessary, the PVA-based resin film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, or the like. For example, by immersing the PVA-based resin film in water and washing it before dyeing, it is possible to clean off stains and antiblocking agents on the surface of the PVA-based resin film and also to swell the PVA-based resin film, thereby preventing uneven dyeing and the like.

[0207] Specific examples of polarizers composed of a laminate of two or more layers include a polarizer composed of a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a polarizer composed of a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate. A polarizer composed of a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be produced, for example, by applying a PVA-based resin solution to the resin substrate and drying the solution to form a PVA-based resin layer on the resin substrate, thereby obtaining a laminate of the resin substrate and the PVA-based resin layer, and then stretching and dyeing the laminate to form the PVA-based resin layer into a polarizer. In a preferred embodiment, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically involves immersing the laminate in an aqueous boric acid solution to stretch it. Furthermore, the stretching may further include, if necessary, in-air stretching of the laminate at a high temperature (e.g., 95°C or higher) before stretching in the boric acid aqueous solution. In addition, in a preferred embodiment, the laminate is subjected to a drying shrinkage treatment in which the laminate is heated while being transported in the longitudinal direction, thereby shrinking the laminate by 2% or more in the width direction. Typically, the laminate is subjected to an in-air auxiliary stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment, in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of the PVA, even when the PVA is coated on a thermoplastic resin, thereby achieving high optical properties. Furthermore, by simultaneously increasing the orientation of the PVA in advance, problems such as a decrease in orientation or dissolution of the PVA when immersed in water in the subsequent dyeing or stretching steps can be prevented, thereby achieving high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disordering of the polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain a halide. This can improve the optical properties of a polarizer obtained through a treatment step in which the laminate is immersed in a liquid, such as a dyeing treatment and an underwater stretching treatment.Furthermore, by shrinking the laminate in the width direction through a drying shrinkage treatment, the optical properties can be improved.The obtained resin substrate / polarizer laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the resin substrate / polarizer laminate, and any appropriate protective layer depending on the purpose may be laminated on the peeled surface. Details of such a method for producing a polarizer are described in, for example, JP-A-2012-73580 and Japanese Patent No. 6,470,455. The entire disclosures of these publications are incorporated herein by reference.

[0208] The polarizer is preferably composed of a laminate of two or more layers, and more preferably composed of a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate.

[0209] The thickness of the polarizer may be any appropriate thickness as long as it does not impair the effects of the present invention. In terms of further exhibiting the effects of the present invention, the thickness of the polarizer is, for example, 80 μm or less, typically 50 μm or less, preferably 1 μm to 30 μm, more preferably 1 μm to 15 μm, even more preferably 1 μm to 12 μm, particularly preferably 2 μm to 10 μm, and most preferably 3 μm to 8 μm.

[0210] Any suitable transparent protective film can be used as the transparent protective film as long as it does not impair the effects of the present invention. Preferably, such a transparent protective film has a moisture permeability of 1200 g / (m 2 ) at 40° C. and 92% RH. 224h) or less. By adjusting the moisture permeability of the transparent protective film within the above range, for example, it is possible to prevent moisture from penetrating into the pressure-sensitive adhesive layer in contact with the transparent protective film, thereby suppressing an increase in the surface resistance of the pressure-sensitive adhesive layer and suppressing cloudiness. Furthermore, the lower the moisture permeability of the transparent protective film, the more it is possible to suppress an increase in the surface resistance of the pressure-sensitive adhesive layer in contact with the transparent protective film. This is thought to be because, for example, when water that has penetrated into the pressure-sensitive adhesive layer circulates in a humid environment, water volatilizes from the polarizing film side including the transparent protective film. At this time, a portion of the antistatic agent in the pressure-sensitive adhesive layer migrates to the polarizing film side, thereby reducing the amount of antistatic agent on the surface of the pressure-sensitive adhesive layer in contact with the polarizing film, and thus increasing the surface resistance of the pressure-sensitive adhesive layer surface. On the other hand, if the moisture permeability of the transparent protective film constituting the polarizing film is low, it is thought that water can be prevented from penetrating into the pressure-sensitive adhesive layer, and an increase in the surface resistance of the pressure-sensitive adhesive layer surface can be suppressed.

[0211] The moisture permeability of the transparent protective film is 1000 g / (m 2 ・24h) or less, and 800g / (m 2 24h) or less, and 700g / (m 2 ・24h) or less, and 600g / (m 2 ・24h) or less, and 500g / (m 2 ・24h) or less, and 400g / (m 2 ・24h) or less.

[0212] From the viewpoint of durability, the lower limit of the moisture permeability of the transparent protective film is preferably 1 g / (m 2 24h) or more, more preferably 3g / (m 2 24h) or more, and particularly preferably 5g / (m 2 ・24 hours or more.

[0213] From the above, the moisture permeability of the transparent protective film is preferably 1 g / (m 2 ・24h)~1200g / (m 2 24h), and 1g / (m 2 ・24h)~1000g / (m 224h), and 1g / (m 2 ・24h)~800g / (m 2 24h), and 1g / (m 2 ・24h)~700g / (m 2 24h), and 3g / (m 2 ・24h)~600g / (m 2 24h), and 3g / (m 2 ・24h)~500g / (m 2 24h), and 5g / (m 2 ・24h)~400g / (m 2 ・24h) may also be used.

[0214] Any suitable material can be used as the material for the transparent protective film as long as it does not impair the effects of the present invention. Examples of such materials include thermoplastic resins that are excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene-based resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. Examples of suitable thermosetting or ultraviolet-curable resins include (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone-based resins. Other examples include glassy polymers such as siloxane-based polymers, and the polymer films described in JP 2001-343529 A (WO 01 / 37007 A). Also usable are resin compositions containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain, for example, a resin composition containing an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer.As the (meth)acrylic resin, for example, a (meth)acrylic resin having a glutarimide structure is used. (Meth)acrylic resins having a glutarimide structure are described, for example, in JP-A Nos. 2006-309033, 2006-317560, 2006-328329, 2006-328334, 2006-337491, 2006-337492, 2006-337493, 2006-337569, 2007-009182, 2009-161744, and 2010-284840. These descriptions are incorporated herein by reference.

[0215] The content of the thermoplastic resin in the transparent protective film is preferably 50% by weight to 100% by weight, more preferably 50% by weight to 99% by weight, even more preferably 60% by weight to 98% by weight, and particularly preferably 70% by weight to 97% by weight.

[0216] Typically, the above-mentioned transparent protective film is bonded to one side of the polarizer, for example, by an adhesive layer, and the other side of the polarizer may be bonded to the above-mentioned transparent protective film, for example, by an adhesive layer, or another thermosetting resin or ultraviolet-curable resin may be provided.

[0217] The transparent protective film may contain one or more suitable additives, such as ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0218] The transparent protective film may have any appropriate thickness as long as it does not impair the effects of the present invention. In order to further exhibit the effects of the present invention, the thickness of the transparent protective film is, for example, 1 μm to 200 μm, preferably 1 μm to 100 μm, more preferably 5 μm to 100 μm, even more preferably 5 μm to 80 μm, and particularly preferably 10 μm to 60 μm. When the transparent protective film has been subjected to a surface treatment, the thickness of the transparent protective film includes the thickness of the layer formed by the surface treatment (surface treatment layer).

[0219] When an adhesive is used to bond the polarizer and the transparent protective film, any appropriate adhesive can be used as the adhesive as long as it is optically transparent and does not impair the effects of the present invention. Examples of such adhesives include water-based adhesives and radical-curing adhesives.

[0220] <<4. Pressure-sensitive Adhesive Film>> The pressure-sensitive adhesive layer that can be used in the pressure-sensitive adhesive layer-attached polarizing film according to an embodiment of the present invention can be made into a pressure-sensitive adhesive film by, for example, combining it with another layer.

[0221] The PSA film includes a PSA layer that can be used in a PSA-layered polarizing film according to an embodiment of the present invention. The PSA film may include any appropriate other layer, as long as it includes a PSA layer that can be used in a PSA-layered polarizing film according to an embodiment of the present invention. Such other layers may be a single layer or two or more layers. Examples of such other layers include a substrate layer, a release liner (sometimes referred to as a release sheet or separator), an antistatic layer, an easy-adhesion layer, an easy-slip layer, a release layer, a hard coat layer, and an anti-reflection layer. A PSA film according to one embodiment has a laminate structure in which a substrate layer, a PSA layer, and a release liner are laminated in this order, with the release liner being the outermost layer. A PSA film according to another embodiment has a laminate structure in which a substrate layer and a PSA layer are laminated in this order, with the PSA layer being the outermost layer. Another PSA film according to another embodiment includes an antistatic layer on the opposite side of the substrate layer from the PSA layer. An easy-adhesion layer may also be provided between the substrate layer and the PSA layer.

[0222] The thickness of the adhesive film is preferably 5.5 μm to 500 μm, more preferably 10 μm to 400 μm, even more preferably 20 μm to 300 μm, even more preferably 30 μm to 200 μm, even more preferably 40 μm to 190 μm, particularly preferably 50 μm to 180 μm, and most preferably 60 μm to 170 μm.

[0223] Figure 2 is a schematic cross-sectional view of a PSA film. In Figure 2, PSA film 200 comprises a release liner 50, a PSA layer 20, and a substrate layer 60. In the embodiment shown in Figure 2, the release liner 50 and the PSA layer 20 are directly laminated together, and the PSA layer 20 and the substrate layer 60 are directly laminated together. The release liner 50 can be peeled off at the time of use. Unlike Figure 1, there may be an easy-adhesion layer or an antistatic layer between the PSA layer 20 and the substrate layer 60, or there may be an antistatic layer on the side of the substrate layer 60 opposite the PSA layer 20.

[0224] The substrate layer may be a single layer or may be two or more layers. The substrate layer may be stretched.

[0225] The thickness of the substrate layer is preferably 4 μm to 450 μm, more preferably 8 μm to 400 μm, still more preferably 12 μm to 350 μm, and particularly preferably 16 μm to 250 μm.

[0226] An antistatic layer containing any suitable antistatic agent such as a conductive polymer, carbon nanotube, ion-conductive polymer, etc. may be provided on the surface of the substrate layer on which the pressure-sensitive adhesive layer is not applied, for the purpose of suppressing the generation of static electricity, etc. Furthermore, for the purpose of forming a roll that is easy to unwind, for example, the substrate layer may be subjected to a release treatment by adding a fatty acid amide, polyethyleneimine, long-chain alkyl additive, etc., or a coating layer made of any suitable release agent such as a silicone-based, long-chain alkyl-based, or fluorine-based release agent may be provided.

[0227] Any appropriate material may be used as the material for the substrate layer depending on the application. Examples include plastic, paper, metal film, nonwoven fabric, etc. Plastic is preferred. That is, the substrate layer is preferably a plastic film. The substrate layer may be made of one material or two or more materials. For example, it may be made of two or more plastics.

[0228] Examples of the plastics include polyester resins, polyolefin resins, cyclic polyolefin resins, polyamide resins, polyimide resins, polyether ether ketone, polyethersulfone, polyarylate resins, and aramid resins. Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include homopolymers of olefin monomers and copolymers of olefin monomers. Specific examples include homopolypropylene; propylene copolymers such as block copolymers, random copolymers, and graft copolymers containing ethylene as a copolymerization component; reactor TPO; ethylene copolymers such as low-density, high-density, linear low-density, and ultra-low-density copolymers; ethylene copolymers such as ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-butyl acrylate copolymers, ethylene-methacrylic acid copolymers, and ethylene-methyl methacrylate copolymers. Examples of cyclic polyolefin resins include norbornene resins.

[0229] The substrate layer may contain any appropriate additives as needed. Examples of additives that may be contained in the substrate layer include antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, fillers, and pigments. The type, number, and amount of additives that may be contained in the substrate layer may be appropriately set depending on the purpose.

[0230] Such a PSA film can exhibit excellent antistatic properties, and the surface resistance value of the PSA layer surface (applied voltage = 100 V, application time 15 seconds) in an environment of a temperature of 25°C and a relative humidity of 50% is preferably 1.0 × 10 12 Ω or less, and more preferably 5.0 × 10 11 Ω or less, and more preferably 1.0 × 10 11 Ω or less, and particularly preferably 5.0 × 10 10 Ω or less, and most preferably 1.0×10 10The lower limit of the surface resistivity is preferably as low as possible from the viewpoint of antistatic properties. 6 Ω or more, and 1.0 × 10 7 It can be Ω or more.

[0231] The PSA film can be produced by any appropriate method, for example, a known method for producing a PSA film including a substrate layer and a PSA layer.

[0232] The pressure-sensitive adhesive layer included in the pressure-sensitive adhesive film may be formed by a formation method generally referred to as a "direct method," or may be formed by a formation method generally referred to as a "transfer method." The direct method is a method in which a pressure-sensitive adhesive composition that forms a pressure-sensitive adhesive that can be used in the pressure-sensitive adhesive layer-attached polarized film according to an embodiment of the present invention is applied to a base layer, and if necessary, heating, irradiation with active energy rays (such as ultraviolet rays), drying, etc., are performed to form a pressure-sensitive adhesive layer. The transfer method is a method in which a pressure-sensitive adhesive composition that forms a pressure-sensitive adhesive that can be used in the pressure-sensitive adhesive layer-attached polarized film according to an embodiment of the present invention is applied to a release paper or the like, and dried to form a pressure-sensitive adhesive layer, and the formed pressure-sensitive adhesive layer is transferred to a base layer.

[0233] Examples of the application method include a gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, air knife coater, spray coater, comma coater, direct coater, and roll brush coater.

[0234] The PSA film can be used for any appropriate purpose. In terms of being able to effectively exhibit the effects of the present invention, the PSA film can be preferably used as at least one film selected from the group consisting of a surface protection film and a reinforcing film.

[0235] The PSA film can exhibit any appropriate peel strength (which may be expressed as adhesive strength) depending on the type of PSA composition.

[0236] The acrylic pressure-sensitive adhesive film (A) including a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive formed from the acrylic pressure-sensitive adhesive composition (A) preferably has a glass peel strength of 0.005 N / 25 mm to 50 N / 25 mm, which will be described as an evaluation in Examples and Comparative Examples below.

[0237] The acrylic pressure-sensitive adhesive film (A) including a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive formed from the acrylic pressure-sensitive adhesive composition (A) preferably has a peel strength (1) against polyimide, which will be described as an evaluation in Examples and Comparative Examples below, of 0.005 N / 25 mm to 50 N / 25 mm.

[0238] The acrylic pressure-sensitive adhesive film (B) including a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive formed from the acrylic pressure-sensitive adhesive composition (B) has a peel strength (2) from polyimide, which will be described as an evaluation in Examples and Comparative Examples below, of preferably 0.001 N / 25 mm to 1 N / 25 mm, more preferably 0.005 N / 25 mm to 0.8 N / 25 mm, even more preferably 0.01 N / 25 mm to 0.6 N / 25 mm, particularly preferably 0.015 N / 25 mm to 0.4 N / 25 mm, and most preferably 0.02 N / 25 mm to 0.2 N / 25 mm, before UV irradiation.

[0239] The acrylic pressure-sensitive adhesive film (B) including a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive formed from the acrylic pressure-sensitive adhesive composition (B) has a polyimide peel strength (2) after UV irradiation, which will be described as an evaluation in the Examples and Comparative Examples below, of preferably 1.5 N / 25 mm or more, more preferably 2 N / 25 mm or more, even more preferably 3 N / 25 mm or more, particularly preferably 4 N / 25 mm or more, and most preferably 5 N / 25 mm or more. The higher the upper limit of the polyimide peel strength (2) after UV irradiation, the better.

[0240] The PSA film can be used for any suitable purpose, such as a surface protection film or reinforcing film to prevent scratches or impart impact resistance to the surfaces of optical or electronic components during processing, assembly, inspection, transportation, etc. in the manufacturing process of optical or electronic devices, or as a joining material for constructing optical or electronic components.

[0241] 5. Optical Device and Electronic Device An optical device according to an embodiment of the present invention includes a polarizing film with a pressure-sensitive adhesive layer according to an embodiment of the present invention. Examples of such optical devices include image display devices. Typical examples of image display devices include liquid crystal display devices and organic EL display devices.

[0242] The above-mentioned PSA films are typically attached to exposed surfaces of optical or electronic components during processing, assembly, inspection, transportation, etc. in the manufacturing process of optical or electronic devices to prevent scratches on the surfaces of the optical or electronic components and to impart impact resistance, and can be suitably used for surface protection and reinforcement of the optical or electronic components. That is, such optical devices include the above-mentioned PSA films. Furthermore, such electronic devices include the above-mentioned PSA films.

[0243] <<6. Application to OCA>> As in the polarized film with an adhesive layer according to an embodiment of the present invention, the ionic compound described above can also be suitably applied to adhesives (e.g., OCA (Optical Clear Adhesive)) and anchor layers (undercoat layers) used in touch panels, displays, and the like. As in the polarized film with an adhesive layer according to an embodiment of the present invention, the ionic compound described above can be incorporated into an adhesive layer, anchor layer, or other layer in, for example, an optical laminate including a polarized film and an adhesive layer, or an optical laminate including a polarized film, an anchor layer, and an adhesive layer (i.e., a polarized film with an adhesive layer according to an embodiment of the present invention), thereby achieving, for example, both excellent antistatic properties and corrosion resistance, and in particular, achieving both highly reliable antistatic properties and excellent corrosion resistance.

[0244] The present invention will be specifically described below using examples, but the present invention is not limited to these examples. The test and evaluation methods used in the examples are as follows. The term "parts" means "parts by weight" unless otherwise specified, and the term "%" means "% by weight" unless otherwise specified.

[0245] <Measurement of moisture permeability of transparent protective film> Measurement was performed in accordance with the moisture permeability test (cup method) of JIS-Z-0208. A transparent protective film cut to a diameter of 60 mm was placed in a moisture permeability cup containing approximately 15 g of calcium chloride, and placed in an incubator at a temperature of 40°C and a relative humidity of 92%. After leaving it for 24 hours, the moisture permeability (g / (m 2 ・24h) was sought.

[0246] <Measurement of Surface Resistivity of the Surface of the Pressure-Sensitive Adhesive Layer of a Polarized Film with a Pressure-Sensitive Adhesive Layer> The release liner was peeled off from the surface of the pressure-sensitive adhesive layer of the polarized film with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples, and the surface resistance of the exposed pressure-sensitive adhesive layer was measured using an MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. (initial surface resistance). Furthermore, the polarized film with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was left to stand for 500 hours in an environment of a temperature of 65°C and a relative humidity of 95%, after which the release liner was peeled off from the surface of the pressure-sensitive adhesive layer, and the surface resistance of the exposed pressure-sensitive adhesive layer was measured using an MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. (surface resistance after 500 hours of high temperature and high humidity). The surface resistance was measured under conditions of an applied voltage of 250 V and a voltage application time of 10 seconds.

[0247] <Measurement of surface resistance value of the surface of the pressure-sensitive adhesive layer> The release liner was peeled off from the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film to expose the pressure-sensitive adhesive layer, and a probe (manufactured by TREK, trade name: Model 152P-2P) was brought into contact with the surface of the pressure-sensitive adhesive layer in an environment of a temperature of 25°C and a relative humidity of 50%, and the surface resistance was measured using a resistivity meter (manufactured by TREK, trade name: Model 152-1) under conditions of an applied voltage of 100 V and a voltage application time of 15 seconds. The numerical value "X.E+Y" shown in the table represents "X×10 Y For example, "3.3.E+11" in the table means "3.3×10 11 " means.

[0248] <Method for Evaluating the Corrosion Resistance of Polarizing Films with Pressure-Sensitive Adhesive Layers> The polarizing films with pressure-sensitive adhesive layers obtained in the Examples and Comparative Examples were cut to a size of 15 mm x 15 mm, the release liners were peeled off, and the films were bonded to conductive glass (alkali-free glass) on whose surface a 0.1 μm-thick aluminum-based metal layer had been formed by sputtering. This was autoclaved at 50°C and 5 atm for 15 minutes to prepare evaluation samples. The obtained evaluation samples were left for 500 hours in an environment of 65°C and 95% relative humidity, and the appearance of the aluminum-based metal layer was observed visually and with an optical microscope and evaluated based on the following criteria: ⊚: No defects; ◯: Defects occurred in some locations, but at a level that is not problematic in practical use; ×: Defects occurred in multiple locations, at a level that would be problematic in practical use.

[0249] <Method for evaluating corrosion resistance of adhesive films (1)> The adhesive films obtained in the reference examples and reference comparative examples were cut to a size of 30 mm x 80 mm, the release liner was peeled off, and the cut pieces were pressed onto 50 mm x 100 mm copper foil with a hand roller to prepare evaluation samples. These evaluation samples were left for 24 hours in an environment of 60°C temperature and 90% relative humidity, and then the surface of the copper foil was visually observed. Evaluation was performed according to the following criteria. ◯: No discoloration due to corrosion was observed on the surface of the copper foil. ×: Discoloration due to corrosion was observed on the surface of the copper foil.

[0250] <Method for evaluating corrosion resistance of pressure-sensitive adhesive films (2)> The pressure-sensitive adhesive films obtained in the reference examples and reference comparative examples were cut to a size of 30 mm x 80 mm, the release liner was peeled off, and the film was pressed onto a 50 mm x 100 mm copper foil with a hand roller. The film was then exposed to ultraviolet light (365 nm LED, cumulative light intensity 1000 mJ / cm 2 ) to photo-cure the adhesive layer, and the resultant was used as an evaluation sample. This evaluation sample was left for 24 hours in an environment of a temperature of 60°C and a relative humidity of 90%, and then the surface of the copper foil was visually observed. Evaluation was performed according to the following criteria. ◯: No discoloration due to corrosion was observed on the surface of the copper foil. ×: Discoloration due to corrosion was observed on the surface of the copper foil.

[0251] <Glass Peel Force> The release liner was peeled off from the surface of a pressure-sensitive adhesive film cut to a size of 25 mm wide x 100 mm long, and the exposed pressure-sensitive adhesive layer side was bonded to a glass plate (soda-lime glass, manufactured by Matsunami Glass Industry Co., Ltd.) using a 2 kg hand roller in one stroke to prepare a test sample. A tensile tester manufactured by Shimadzu Corporation under the trade name "Autograph AG-Xplus HS 6000 mm / min High-Speed ​​Model (AG-50NX plus)" was used, and the test sample was set in the tensile tester. The pressure-sensitive adhesive film was peeled from the glass plate at a tensile speed of 300 mm / min and a peel angle of 180 degrees in an environment of 25°C and 50% relative humidity, and the load at this time was measured, and the average load was taken as the glass peel force.

[0252] <Peel force to polyimide (1)> A 25 μm thick polyimide film (Ube Industries, Ltd., "Upilex 25S") was attached to a glass plate via double-sided adhesive tape (Nitto Denko Corporation, "No. 531") to obtain a polyimide film substrate for measurement. A 25 mm wide x 100 mm long piece of PSA film was cut out, and the release liner was peeled off from the surface. The exposed PSA layer side was then attached to the polyimide film substrate for measurement using a 2 kg hand roller in one stroke to prepare a test sample. A tensile tester manufactured by Shimadzu Corporation under the trade name "Autograph AG-Xplus HS 6000 mm / min high-speed model (AG-50NX plus)" was used, and a test sample was set in the tensile tester. The load when the PSA film was peeled from the polyimide film substrate for measurement was measured at a tensile speed of 300 mm / min and a peel angle of 180 degrees in an environment of a temperature of 25°C and a relative humidity of 50%, and the average load at this time was taken as the polyimide peel force.

[0253] <Peel Force to Polyimide (2)> A 25 μm thick polyimide film (Ube Industries, Ltd., "Upilex 25S") was attached to a glass plate via double-sided adhesive tape (Nitto Denko Corporation, "No. 531") to obtain a polyimide film substrate for measurement. The release liner was peeled off from the surface of a pressure-sensitive adhesive film cut into a size 25 mm wide x 100 mm long, and the exposed pressure-sensitive adhesive layer side was attached to the polyimide film substrate for measurement using a 2 kg hand roller in one stroke to obtain a test sample before photocuring. Ultraviolet light (365 nm LED, cumulative light amount 1000 mJ / cm) was applied from the pressure-sensitive adhesive film side (PET film substrate side) of the test sample before photocuring. 2 The pressure-sensitive adhesive layer was photocured by irradiating the sample with light, and the photocured test sample was prepared. Each test sample was set in a tensile tester manufactured by Shimadzu Corporation under the trade name "Autograph AG-Xplus HS 6000 mm / min high-speed model (AG-50NX plus)." The test sample was then measured at a temperature of 25°C, a relative humidity of 50%, a tensile speed of 300 mm / min, and a peel angle of 180° when the pressure-sensitive adhesive film was peeled from the polyimide film substrate for measurement. The average load measured was defined as the peel force to polyimide.

[0254] <Ionic Compounds Used in Examples, Comparative Examples, Reference Examples, and Reference Comparative Examples> The ionic compounds used in the Examples, Comparative Examples, Reference Examples, and Reference Comparative Examples are as follows: 1-hexyl-3-methylimidazolium bis(oxalate)borate 1-octyl-3-methylimidazolium bis(oxalate)borate Lithium bis(oxalate)borate 1-ethyl-3-methylimidazolium dicyanamide 1-ethyl-3-methylimidazolium p-toluenesulfonate 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide Lithium bis(trifluoromethanesulfonyl)imide

[0255] [Production Example 1]: Preparation of Polarizing Film (P1) A long roll of a 30 μm-thick polyvinyl alcohol (PVA)-based resin film (manufactured by Kuraray Co., Ltd., product name "PE3000") was uniaxially stretched in the longitudinal direction to 5.9 times its original length using a roll stretching machine, while undergoing swelling, dyeing, crosslinking, and washing treatments, and finally drying treatment to obtain a 12 μm-thick polarizer. Specifically, in the swelling treatment, the film was stretched 2.2 times while treating with pure water at 20°C. In the dyeing treatment, the film was stretched 1.4 times while treating at 30°C in an aqueous solution whose iodine concentration was adjusted so that the resulting polarizer had a single transmittance of 45.0%. In the aqueous solution, the weight ratio of iodine to potassium iodide was 1:7. A two-stage crosslinking treatment was employed. In the first stage of the crosslinking treatment, the film was stretched 1.2 times while treating in a boric acid / potassium iodide aqueous solution at 40°C. The boric acid content of this aqueous solution was 5.0% and the potassium iodide content was 3.0%. In the second crosslinking treatment, the film was stretched 1.6 times while being treated in a boric acid / potassium iodide aqueous solution at 65°C. The boric acid content of this aqueous solution was 4.3% and the potassium iodide content was 5.0%. In the washing treatment, a potassium iodide aqueous solution at 20°C was used. The potassium iodide content of the washing treatment aqueous solution was 2.6%. The drying treatment was carried out at 70°C for 5 minutes. A 32 μm-thick triacetyl cellulose (TAC) film having a hard coat (HC) layer on one side of the TAC film was bonded to one side of the polarizer using a PVA-based adhesive. A 13 μm-thick unstretched cycloolefin polymer (COP) film was attached to the other surface of the polarizer using a PVA-based adhesive to prepare a polarizing film (P1) having a TAC protective layer / PVA polarizer / COP protective layer structure. A hard coat layer was provided as a surface treatment layer on the TAC protective layer side of the polarizing film (P1).

[0256] [Production Example 2]: Production of polarizing film (P2) A polarizing film (P2) having a structure of TAC protective layer / PVA polarizer / CAT protective layer was produced in the same manner as in Production Example 1, except that a 25 μm-thick acrylic (CAT) film was attached to the other surface of the polarizer instead of the COP film using a PVA-based adhesive. A hard coat layer was provided as a surface treatment layer on the surface of this polarizing film (P2) facing the TAC protective layer.

[0257] [Production Example 3]: Preparation of Acrylic Polymer (1) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 80.5 parts by weight of butyl acrylate (BA), 0.5 parts by weight of 4-hydroxybutyl acrylate (4HBA), and 19 parts by weight of benzyl acrylate (BzA) as raw monomer components. With respect to 100 parts by weight of the charged raw monomer components, 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added. Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the liquid temperature in the flask was maintained at around 55°C for 8 hours to carry out a polymerization reaction, thereby preparing a solution of acrylic polymer (1) with a weight average molecular weight (Mw) of 1.6 million and an Mw / Mn value of 3.7.

[0258] [Production Example 4]: Preparation of Acrylic Polymer (2) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 80 parts by weight of butyl acrylate (BA), 0.5 parts by weight of 4-hydroxybutyl acrylate (4HBA), 19 parts by weight of benzyl acrylate (BzA), and 0.5 parts by weight of 2-methoxyethyl acrylate (MEA) as raw monomer components. 100 parts by weight of the charged raw monomer components were charged with 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent. Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the temperature in the flask was maintained at around 55°C for 8 hours to produce a solution of acrylic polymer (2) with a weight average molecular weight (Mw) of 1.6 million and Mw / Mn = 3.7.

[0259] [Production Example 5]: Preparation of Acrylic Polymer (3) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 70.5 parts by weight of butyl acrylate (BA), 0.5 parts by weight of 4-hydroxybutyl acrylate (4HBA), 19 parts by weight of benzyl acrylate (BzA), and 10 parts by weight of 2-methoxyethyl acrylate (MEA) as raw monomer components. 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added to 100 parts by weight of the charged raw monomer components. Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the temperature in the flask was maintained at around 55°C for 8 hours to carry out a polymerization reaction. A solution of acrylic polymer (3) with a weight average molecular weight (Mw) of 1.6 million and Mw / Mn = 3.5 was prepared.

[0260] [Production Example 6]: Preparation of Acrylic Polymer (4) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 30.5 parts by weight of butyl acrylate (BA), 0.5 parts by weight of 4-hydroxybutyl acrylate (4HBA), 19 parts by weight of benzyl acrylate (BzA), and 50 parts by weight of 2-methoxyethyl acrylate (MEA) as raw monomer components. 100 parts by weight of the charged raw monomer components were charged with 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent. Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the liquid temperature in the flask was maintained at around 55°C for 8 hours to produce a solution of acrylic polymer (4) with a weight average molecular weight (Mw) of 1.7 million and Mw / Mn = 3.5.

[0261] [Production Example 7]: Preparation of Acrylic Polymer (5) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 77.5 parts by weight of butyl acrylate (BA), 0.5 parts by weight of 4-hydroxybutyl acrylate (4HBA), 19 parts by weight of benzyl acrylate (BzA), and 3 parts by weight of N-vinyl-2-pyrrolidone (NVP) as raw monomer components. 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added to 100 parts by weight of the charged raw monomer components. Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the temperature in the flask was maintained at around 55°C for 8 hours to carry out a polymerization reaction, thereby preparing a solution of acrylic polymer (5) with a weight average molecular weight (Mw) of 1.6 million and Mw / Mn = 3.6.

[0262] [Production Example 8]: Preparation of Acrylic Polymer (6) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 99 parts by weight of butyl acrylate (BA) and 1 part by weight of 4-hydroxybutyl acrylate (4HBA) as raw monomer components. To 100 parts by weight of the charged raw monomer components, 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added. Nitrogen gas was introduced with gentle stirring to replace the atmosphere with nitrogen, and the liquid temperature in the flask was maintained at around 55°C for 8 hours to carry out a polymerization reaction, thereby preparing a solution of acrylic polymer (6) with a weight average molecular weight (Mw) of 1,600,000 and Mw / Mn = 4.0.

[0263] [Production Example 9]: Preparation of Acrylic Polymer (7) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 95.1 parts by weight of butyl acrylate (BA), 4.8 parts by weight of acrylic acid (AA), and 0.1 parts by weight of 4-hydroxybutyl acrylate (4HBA) as raw monomer components. To 100 parts by weight of the charged raw monomer components, 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added. Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the liquid temperature in the flask was maintained at around 55°C for 8 hours to produce a solution of acrylic polymer (7) with a weight average molecular weight (Mw) of 2,000,000 and Mw / Mn = 3.9.

[0264] [Production Example 10]: Production of Acrylic Polymer A A reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube was charged with 95 parts by weight of butyl acrylate (BA) and 5 parts by weight of acrylic acid (AA) as monomers, 0.2 parts by weight of azobisisobutyronitrile (AIBN) as a polymerization initiator, and 233 parts by weight of ethyl acetate as a solvent, followed by flowing nitrogen gas and nitrogen substitution for about 1 hour while stirring. Thereafter, the mixture was heated to 60°C and reacted for 7 hours to obtain a solution of acrylic polymer A having a weight average molecular weight (Mw) of 600,000.

[0265] [Production Example 11]: Production of Acrylic Polymer B A reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube was charged with 91 parts by weight of 2-ethylhexyl acrylate (2EHA) and 9 parts by weight of 4-hydroxybutyl acrylate (4HBA) as monomers, 0.2 parts by weight of azobisisobutyronitrile (AIBN) as a polymerization initiator, and 233 parts by weight of ethyl acetate as a solvent, and nitrogen gas was introduced and purged with nitrogen for about 1 hour while stirring. Thereafter, the mixture was heated to 60°C and reacted for 7 hours to obtain a solution of acrylic polymer B having a weight average molecular weight (Mw) of 600,000.

[0266] [Production Example 12]: Production of Acrylic Polymer C

[0043] A reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube was charged with 90 parts by weight of n-octyl acrylate (NOAA) and 10 parts by weight of 4-hydroxybutyl acrylate (4HBA) as monomers, 0.2 parts by weight of azobisisobutyronitrile (AIBN) as a polymerization initiator, and 233 parts by weight of ethyl acetate as a solvent, and nitrogen gas was introduced and purged with nitrogen for about 1 hour while stirring. The mixture was then heated to 60°C and reacted for 7 hours to obtain a solution of acrylic polymer C having a weight average molecular weight (Mw) of 600,000.

[0267] [Production Example 13]: Production of acrylic oligomer A reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube was charged with 95 parts by weight of cyclohexyl methacrylate and 5 parts by weight of acrylic acid (AA) as monomers, 0.2 parts by weight of azobisisobutyronitrile (AIBN) as a polymerization initiator, and 103.2 parts by weight of toluene as a solvent, followed by flowing nitrogen gas and nitrogen substitution for about 1 hour while stirring. Thereafter, the mixture was heated to 70°C, reacted for 3 hours, and then further reacted at 75°C for 2 hours to obtain a solution of an acrylic oligomer having a weight average molecular weight (Mw) of 4000.

[0268] Example 1 To the solution of acrylic polymer (1) obtained in Production Example 3 (100 parts by weight as the solid content of acrylic polymer (1)), 0.1 parts by weight of an isocyanate crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D160N", trimethylolpropane hexamethylene diisocyanate) and 0.3 parts by weight of a peroxide crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide) as crosslinking agents, and 0.3 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound were added and mixed uniformly to prepare a pressure-sensitive adhesive composition (1). The pressure-sensitive adhesive composition (1) was applied to the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, product name "MRF38") that had been treated with a silicone-based release agent, so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and the coating was dried at 155° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the polyethylene terephthalate (PET) film. The formed pressure-sensitive adhesive layer was transferred to one side of the polarized film (P1) obtained in Production Example 1, to obtain a polarized film (1) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0269] A pressure-sensitive adhesive composition (2) and a polarized film (2) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 1, except that 0.3 parts by weight of lithium bis(oxalate)borate was used instead of 0.3 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate. The results are shown in Table 1.

[0270] A pressure-sensitive adhesive composition (3) and a polarized film (3) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 1, except that the amount of 1-hexyl-3-methylimidazolium bis(oxalate)borate used was changed to 6 parts by weight. The results are shown in Table 1.

[0271] Example 4 To the solution of acrylic polymer (2) obtained in Production Example 4 (100 parts by weight as the solid content of acrylic polymer (2)), 0.1 parts by weight of an isocyanate crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D160N", trimethylolpropane hexamethylene diisocyanate) and 0.3 parts by weight of a peroxide crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide) as crosslinking agents, and 0.3 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound were added and mixed uniformly to prepare a pressure-sensitive adhesive composition (4). The pressure-sensitive adhesive composition (4) was applied to the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, product name "MRF38") that had been treated with a silicone-based release agent, so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and the coating was dried at 155° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the polyethylene terephthalate (PET) film. The formed pressure-sensitive adhesive layer was transferred to one side of the polarized film (P1) obtained in Production Example 1, to obtain a polarized film (4) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0272] Example 5 To the solution of acrylic polymer (3) obtained in Production Example 5 (100 parts by weight as the solid content of acrylic polymer (3)), 0.1 parts by weight of an isocyanate crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D160N", trimethylolpropane hexamethylene diisocyanate) and 0.3 parts by weight of a peroxide crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide) as crosslinking agents, and 0.3 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound were added and mixed uniformly to prepare a pressure-sensitive adhesive composition (5). The pressure-sensitive adhesive composition (5) was applied to the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, product name "MRF38") that had been treated with a silicone-based release agent, so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and the coating was dried at 155° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the polyethylene terephthalate (PET) film. The formed pressure-sensitive adhesive layer was transferred to one side of the polarized film (P1) obtained in Production Example 1, to obtain a polarized film (5) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0273] Example 6 (Preparation of Photocurable Pressure-Sensitive Adhesive Composition (6)) 89.5 parts by weight of n-butyl acrylate (BA), 0.5 parts by weight of 4-hydroxybutyl acrylate (4HBA), 10 parts by weight of 2-methoxyethyl acrylate (MEA), and 0.2 parts by weight of Omnirad 127D (manufactured by IGM Resins B.V.) as a photopolymerization initiator were placed in a four-neck flask. Next, the liquid in the flask was irradiated with ultraviolet light under a nitrogen atmosphere to obtain a monomer syrup in which the monomers were partially photopolymerized. The ultraviolet light irradiation was continued until the viscosity of the liquid in the flask (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30°C) reached 20 Pa s. The polymerization conversion rate of the obtained monomer syrup was 5% by weight. Next, 0.12 parts by weight of 1,9-nonanediol diacrylate (NDDA) as a crosslinking agent per 100 parts by weight of the monomer syrup (solid content: 5 wt%) and 0.3 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound per 100 parts by weight of the monomer syrup (solid content: 5 wt%) were added to the resulting monomer syrup and mixed uniformly to obtain a photocurable pressure-sensitive adhesive composition (6). (Preparation of Polarized Film (6) with Pressure-Sensitive Adhesive Layer) The photocurable pressure-sensitive adhesive composition (6) was applied with an applicator to the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, product name "MRF38") that had been treated with a silicone-based release agent to form a coating layer (thickness: 20 μm). Next, a release liner was placed on the formed coating layer to obtain a first laminate. The release liner was placed so that the release layer was in contact with the coating layer. Next, an illuminance of 3.5 mW / cm was applied from the PET film side of the first laminate. 2 and irradiation time 460 seconds (integrated light amount 1600 mJ / cm 2) was irradiated with light. An LED was used as the light source, and the peak wavelength of the irradiated light was 340 nm. This photocured the coating layer, and a pressure-sensitive adhesive sheet (thickness 20 μm) sandwiched between the PET film and the release liner was obtained. The illuminance of the light was measured using an illuminance meter (UD-T3040T2, manufactured by Topcon Technohouse Co., Ltd.) at a position near the ultraviolet light incident surface of the PET film. The obtained pressure-sensitive adhesive sheet was used as a pressure-sensitive adhesive layer and transferred to one side of the polarized film (P1) obtained in Production Example 1, to obtain a polarized film (6) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0274] Example 7 To the solution of acrylic polymer (4) obtained in Production Example 6 (100 parts by weight as the solid content of acrylic polymer (4)), 0.1 parts by weight of an isocyanate crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D160N", trimethylolpropane hexamethylene diisocyanate) and 0.3 parts by weight of a peroxide crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide) as crosslinking agents, and 0.2 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound were added and mixed uniformly to prepare a pressure-sensitive adhesive composition (7). The pressure-sensitive adhesive composition (7) was applied to the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, product name "MRF38") that had been treated with a silicone-based release agent, so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and the coating was dried at 155° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the polyethylene terephthalate (PET) film. The formed pressure-sensitive adhesive layer was transferred to one side of the polarized film (P1) obtained in Production Example 1, to obtain a polarized film (7) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0275] A pressure-sensitive adhesive composition (8) and a polarized film with a pressure-sensitive adhesive layer (8) were obtained in the same manner as in Example 7, except that the amount of 1-hexyl-3-methylimidazolium bis(oxalate)borate used was changed to 6 parts by weight. The results are shown in Table 1.

[0276] [Example 9] A pressure-sensitive adhesive composition (9) and a polarized film (9) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 3, except that the polarized film (P2) obtained in Production Example 2 was used instead of the polarized film (P1) obtained in Production Example 1. The results are shown in Table 1.

[0277] [Example 10] A pressure-sensitive adhesive composition (10) and a polarized film (10) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 9, except that the acrylic polymer (3) obtained in Production Example 5 (100 parts by weight as the solid content of the acrylic polymer (3)) was used instead of the acrylic polymer (1) obtained in Production Example 3 (100 parts by weight as the solid content of the acrylic polymer (1)). The results are shown in Table 1.

[0278] Example 11 A pressure-sensitive adhesive composition (11) and a polarized film (11) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 9, except that the acrylic polymer (5) obtained in Production Example 7 (100 parts by weight as the solids content of the acrylic polymer (5)) was used instead of the acrylic polymer (1) obtained in Production Example 3 (100 parts by weight as the solids content of the acrylic polymer (1)). The results are shown in Table 1.

[0279] Example 12 To the solution of acrylic polymer (6) obtained in Production Example 8 (100 parts by weight as the solid content of acrylic polymer (6)), 0.1 parts by weight of an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name "Takenate D110N", trimethylolpropane / xylylene diisocyanate adduct) and 0.3 parts by weight of a peroxide crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide) as a crosslinking agent, and 6 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound were added and mixed uniformly to prepare a pressure-sensitive adhesive composition (12). The pressure-sensitive adhesive composition (12) was applied to the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, product name "MRF38") that had been treated with a silicone-based release agent, so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and the coating was dried at 155° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the polyethylene terephthalate (PET) film. The formed pressure-sensitive adhesive layer was transferred to one side of the polarized film (P1) obtained in Production Example 1, to obtain a polarized film (12) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0280] Example 13 A pressure-sensitive adhesive composition (13) and a polarized film (13) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 12, except that the acrylic polymer (7) obtained in Production Example 9 (100 parts by weight of the solids content of the acrylic polymer (7)) was used instead of the solution of the acrylic polymer (6) obtained in Production Example 8 (100 parts by weight of the solids content of the acrylic polymer (6)), and 0.45 parts by weight of an isocyanate-based crosslinking agent (manufactured by Tosoh Corporation, trade name "Coronate L", trimethylolpropane / tolylene diisocyanate adduct) and 0.1 parts by weight of a peroxide-based crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide) were used as the crosslinking agent. The results are shown in Table 1.

[0281] [Example 14] To the solution of acrylic polymer A obtained in Production Example 10 (100 parts by weight as the solid content of acrylic polymer A), 0.45 parts by weight of a tetrafunctional epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Company, trade name "Tetrad C") as a crosslinking agent, 0.2 parts by weight of zirconium tetraacetylacetonate as a crosslinking catalyst, 30 parts by weight as the solid content of polyethylene glycol #200 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-200") as a photocuring agent, 0.3 parts by weight of Omnirad 651 (manufactured by IGM Resins) as a photopolymerization initiator, and 6 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound were added and mixed uniformly to prepare a pressure-sensitive adhesive composition (14). The pressure-sensitive adhesive composition (14) was applied to the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, product name "MRF38") that had been treated with a silicone-based release agent, so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and the coating was dried at 155° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the polyethylene terephthalate (PET) film. The formed pressure-sensitive adhesive layer was transferred to one side of the polarized film (P1) obtained in Production Example 1, to obtain a polarized film (14) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0282] A pressure-sensitive adhesive composition (C1) and a polarized film (C1) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 3, except that 6 parts by weight of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide was used instead of 6 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate. The results are shown in Table 1.

[0283] A pressure-sensitive adhesive composition (C2) and a polarized film (C2) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 9, except that 6 parts by weight of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide was used instead of 6 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate. The results are shown in Table 1.

[0284] A pressure-sensitive adhesive composition (C3) and a polarized film (C3) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 12, except that 6 parts by weight of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide was used instead of 6 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate. The results are shown in Table 1.

[0285] A pressure-sensitive adhesive composition (C4) and a polarized film (C4) with a pressure-sensitive adhesive layer were obtained in the same manner as in Example 13, except that 6 parts by weight of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide was used instead of 6 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate. The results are shown in Table 1.

[0286]

[0287] Reference Example 1 To the solution of acrylic polymer A obtained in Production Example 10 (100 parts by weight as the solid content of acrylic polymer A), 0.1 parts by weight of a tetrafunctional epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Company, trade name "Tetrad C") as a crosslinking agent, 25 parts by weight as the solid content of the acrylic oligomer obtained in Production Example 4, and 0.3 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound were added and mixed uniformly to prepare a pressure-sensitive adhesive composition (R1). The pressure-sensitive adhesive composition (R1) was applied to a 75 μm-thick polyethylene terephthalate film substrate using an applicator so that the thickness after drying would be 13 μm. After drying at 130°C for 1 minute to remove the solvent, the release-treated surface of a release liner (a 25 μm-thick polyethylene terephthalate film with one side treated with a silicone release agent) was bonded to the surface to which the pressure-sensitive adhesive composition was applied. Thereafter, an aging treatment was carried out for 4 days in an atmosphere at 25°C to promote crosslinking, thereby obtaining a PSA film (R1) in which the PSA layer was fixedly laminated onto the polyethylene terephthalate film substrate and a release liner was temporarily attached thereon. The results are shown in Table 2.

[0288] [Reference Examples 2 to 7, Reference Comparative Examples 1 to 7] Pressure-sensitive adhesive compositions (R2) to (R7), (RC1) to (RC7) and PSA films (R2) to (R7), (RC1) to (RC7) were obtained in the same manner as Reference Example 1, except that the type and amount of ionic compound added were changed as shown in Table 2. The results are shown in Table 2.

[0289]

[0290] Reference Example 8 To the solution of acrylic polymer A obtained in Production Example 10 (100 parts by weight as the solid content of acrylic polymer A), 0.45 parts by weight of a tetrafunctional epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Company, trade name "Tetrad C") as a crosslinking agent, 0.2 parts by weight of zirconium tetraacetylacetonate as a crosslinking catalyst, 30 parts by weight as the solid content of polyethylene glycol #200 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-200") as a photocuring agent, 0.3 parts by weight of Omnirad 651 (manufactured by IGM Resins) as a photopolymerization initiator, and 0.05 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate)borate as an ionic compound were added and mixed uniformly to prepare a pressure-sensitive adhesive composition (R8). The above-mentioned pressure-sensitive adhesive composition (R8) was applied to a 75 μm thick polyethylene terephthalate film substrate using an applicator so that the thickness after drying was 13 μm. After drying at 130 ° C for 1 minute to remove the solvent, the release-treated surface of a release liner (a 25 μm thick polyethylene terephthalate film with one side treated with silicone release) was attached to the surface coated with the pressure-sensitive adhesive composition. Then, aging treatment was performed for 4 days in an atmosphere of 25 ° C to promote crosslinking, and a pressure-sensitive adhesive film (R8) was obtained in which the pressure-sensitive adhesive layer was fixedly laminated on the polyethylene terephthalate film substrate and the release liner was temporarily attached thereon. The results are shown in Table 3.

[0291] [Reference Examples 9 to 19, Reference Comparative Examples 8 to 14] Pressure-sensitive adhesive compositions (R9) to (R19), (RC8) to (RC14) and pressure-sensitive adhesive films (R9) to (R19), (RC8) to (RC14) were obtained in the same manner as in Reference Example 8, except that the type and amount of ionic compound added were changed as shown in Table 3. The results are shown in Table 3.

[0292] [Reference Example 20] To the solution of acrylic polymer B obtained in Production Example 11 (100 parts by weight as solids of acrylic polymer B), 0.1 parts by weight of an isocyanurate of hexamethylene diisocyanate (manufactured by Tosoh, trade name "Coronate HX") as a crosslinking agent, 0.02 parts by weight of iron diacetylacetonate as a crosslinking catalyst, 10 parts by weight of polyethylene glycol #200 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-200") as a photocuring agent in solids, 0.3 parts by weight of Omnirad 651 (manufactured by IGM Resins) as a photopolymerization initiator, 0.2 parts by weight of 1-hexyl-3-methylimidazolium bis (oxalate) borate as an ionic compound was added, and mixed uniformly to prepare a pressure-sensitive adhesive composition (R20). The above-mentioned pressure-sensitive adhesive composition (R20) was applied to a 75 μm thick polyethylene terephthalate film substrate using an applicator so that the thickness after drying was 13 μm. After drying at 130 ° C for 1 minute to remove the solvent, the release-treated surface of a release liner (a 25 μm thick polyethylene terephthalate film with one side treated with silicone release) was attached to the surface coated with the pressure-sensitive adhesive composition. Then, aging treatment was performed for 4 days in an atmosphere of 25 ° C to promote crosslinking, and a pressure-sensitive adhesive film (R20) was obtained in which a pressure-sensitive adhesive sheet was fixedly laminated on a polyethylene terephthalate film substrate and a release liner was temporarily attached thereon. The results are shown in Table 3.

[0293] [Reference Examples 21 and 22] Pressure-sensitive adhesive compositions (R21) and (R22) and pressure-sensitive adhesive films (R21) and (R22) were obtained in the same manner as in Reference Example 20, except that the type of acrylic polymer and the type and amount of ionic compound added were changed as shown in Table 3. The results are shown in Table 3.

[0294]

[0295] [Reference Example 23] For each of the PSA films (R1) to (R22) obtained in Reference Examples 1 to 22, the release liner was peeled off, and the PSA layer side was attached to a polarizing plate (manufactured by Nitto Denko Corporation, product name "TEG1465DUHC"), which is an optical component, to obtain an optical device.

[0296] Reference Example 24 For each of the PSA films (R1) to (R22) obtained in Reference Examples 1 to 22, the release liner was peeled off, and the PSA layer side was attached to a conductive film (manufactured by Nitto Denko Corporation, product name "ELECRYSTA V270L-TFMP"), which is an electronic component, to obtain an electronic device.

[0297] The polarizing film with a pressure-sensitive adhesive layer according to the embodiment of the present invention can be used in optical devices such as image display devices, for example.

Claims

1. A polarizing film with an adhesive layer including an adhesive layer and a polarizing film, wherein the adhesive layer is composed of an adhesive formed from an adhesive composition, the adhesive composition includes a base polymer and an ionic compound, the ionic compound consists of a cationic species and an anionic species, and the anionic species is at least one selected from the group consisting of a borate anion and a dicyanamide anion. A polarizing film with an adhesive layer.

2. The polarizing film with an adhesive layer according to claim 1, wherein the cationic species is at least one selected from the group consisting of an onium cation and a metal cation.

3. The polarizing film with an adhesive layer according to claim 1, wherein the borate anion does not contain both a fluorine element and a sulfur element.

4. The polarizing film with an adhesive layer according to claim 1, wherein the base polymer is at least one selected from an acrylic polymer, a polyol, and a urethane prepolymer.

5. The polarizing film with an adhesive layer according to claim 4, wherein the base polymer is an acrylic polymer, and the monomer components constituting the acrylic polymer include at least one selected from the group consisting of an alkyl (meth)acrylate in which the alkyl group of the alkyl ester moiety has 4 to 12 carbon atoms and at least one selected from the group consisting of a (meth)acrylate having an OH group and (meth)acrylic acid.

6. The polarizing film with an adhesive layer according to claim 4, wherein the base polymer is an acrylic polymer, and the monomer components constituting the acrylic polymer include at least one selected from the group consisting of an amide group-containing monomer, an aromatic ring-containing (meth)acrylate, and an alkoxyalkyl (meth)acrylate.

7. The polarizing film with an adhesive layer according to claim 1, wherein the amount of the ionic compound relative to 100 parts by weight of the base polymer is 0.001 part by weight to 30 parts by weight.

8. An optical device including the polarizing film with an adhesive layer according to any one of claims 1 to 7.

Images