Polarization film having adhesive layer, and optical device

Abstract

To provide a polarization film having an adhesive layer capable of exhibiting highly reliable anti-static properties and excellent anti-corrosion properties simultaneously, and an optical device including the polarization film having an adhesive layer.SOLUTION: A polarization film having an adhesive layer includes an adhesive layer and a polarization film. The adhesive layer is composed of an adhesive agent formed from an adhesive composition. The adhesive composition includes a base polymer and an ionic compound. The ionic composition includes cationic species and anionic species. The anionic species is at least one kind selected from a group composed of borate anion and dicyanamide anion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a polarizing film with an adhesive layer. It also relates to an optical device including such a polarizing film with an adhesive layer.

Background Art

[0002] A polarizing film with an adhesive layer may be used as a member for constructing an optical member.

[0003] Optical members and polarizing films with an adhesive layer as described above have high electrical insulation and generate static electricity due to friction and peeling. If such static electricity remains, for example, when a voltage is applied to a liquid crystal, there is a concern that the alignment of liquid crystal molecules may be lost or defects may occur in the liquid crystal panel. Also, the presence of static electricity can be a factor in attracting dust and reducing workability.

[0004] A technique has been reported for imparting antistatic properties to an adhesive film by containing an ionic compound as an antistatic agent in the adhesive layer (for example, Patent Document 1).

[0005] However, when a conventional polarizing film with an antistatic agent-containing adhesive layer is used, for example, as a member for constructing 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 an adhesive layer is used in a harsh environment such as a high-temperature and high-humidity environment, there is a problem that the occurrence of corrosion as described above becomes prominent. Also, when a polarizing film with an adhesive layer is used in such a harsh environment, the reliability of the antistatic property deteriorates, for example, the surface resistance value of the adhesive layer fluctuates.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a polarizing film with an adhesive layer capable of achieving both high reliability antistatic properties and excellent corrosion resistance, and an optical device including the polarizing film with an adhesive layer.

Means for Solving the Problems

[0008] [1] The polarizing film with an adhesive layer according to an embodiment of the present invention is a polarizing film with an adhesive layer including an adhesive layer and a polarizing film, the adhesive layer being composed of an adhesive formed from an adhesive composition, the adhesive composition including a base polymer and an ionic compound, the ionic compound being composed of a cationic species and an anionic species, and the anionic species being at least one selected from the group consisting of a borate anion and a dicyanamide anion. [2] In the polarizing film with an adhesive layer according to [1] above, the cationic species may be at least one selected from the group consisting of an onium cation and a metal cation. [3] In the polarizing film with an adhesive layer according to [1] or [2] above, the borate anion may not contain both a fluorine element and a sulfur element. [4] In the polarizing film with an adhesive layer according to any one of [1] to [3] above, the base polymer may be at least one selected from the group consisting of an acrylic polymer, a polyol, and a urethane prepolymer. [5] In the polarizing film with an adhesive layer according to [4] above, the base polymer is an acrylic polymer, and the monomer component constituting the acrylic polymer may 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 (meth)acrylic acid esters having an OH group and (meth)acrylic acid. [6] In the polarizing film with an adhesive layer described in [4] above, the base polymer is an acrylic polymer, and the monomer component constituting the acrylic polymer may contain 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] In the polarizing film with an adhesive layer according to any one of [1] to [6] above, the amount of the ionic compound with respect to 100 parts by weight of the base polymer may be 0.001 part by weight to 30 parts by weight. [8] The optical device according to an embodiment of the present invention includes the polarizing film with an adhesive layer according to any one of [1] to [7] above.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a polarizing film with an adhesive layer that can exhibit both high reliability antistatic properties and excellent corrosion resistance, and an optical device including the polarizing film with an adhesive layer.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] In this specification, when there is an expression " (meth)acryl ", it means "acryl and / or methacryl"; when there is an expression " (meth)acrylate ", it means "acrylate and / or methacrylate"; when there is an expression " (meth)allyl ", it means "allyl and / or methallyl"; when there is an expression " (meth)acrolein ", it means "acrolein and / or methacrolein". Also, in this specification, when there is an expression " acid (salt) ", it means "acid and / or its salt". Examples of the salt include alkali metal salts and alkaline earth metal salts, and specifically, for example, sodium salts, potassium salts and the like.

[0012] In this specification, when there is "main component", it preferably means 50 wt% to 100 wt%, more preferably 60 wt% to 100 wt%, still more preferably 70 wt% to 100 wt%, particularly preferably 80 wt% to 100 wt%, and most preferably 90 wt% to 100 wt%.

[0013] ≪≪1. Overall configuration≫≫ As shown in the schematic cross-sectional view of FIG. 1, a polarizing film 100 with an adhesive layer according to one embodiment of the present invention has a polarizing film 10 and an adhesive layer 20 in this order. In FIG. 1, an anchor layer 30 is provided between the polarizing film 10 and the adhesive layer 20, but the anchor layer 30 is an optional member and may not be provided. As the anchor layer, any appropriate anchor layer can be adopted as long as the effects of the present invention are not impaired.

[0014] A surface treatment layer 40 can be provided on the side of the polarizing film 10 opposite to the adhesive layer 20. FIG. 1 illustrates the case where the polarizing film 100 with an adhesive layer has a surface treatment layer 40. As the surface treatment layer, any appropriate surface treatment layer can be adopted as long as the effects of the present invention are not impaired.

[0015] Although not shown in Fig. 1, a release liner (sometimes referred to as a release sheet or separator) can be provided on the exposed surface of the adhesive layer 20 of the polarizing film 100 with an adhesive layer, and a surface protection film can be provided on the exposed surface of the polarizing film 10. Further, each component member 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 the release liner include a release liner in which the surface of a base material (liner base material) such as paper or a plastic film is silicone-treated, and a release liner in which the surface of a base material (liner base material) such as paper or a plastic film is laminated with a polyolefin resin.

[0017] Examples of the plastic film as the liner base material include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

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

[0019] The polarizing film with an adhesive layer according to an embodiment of the present invention can be manufactured by any suitable method without impairing the effects of the present invention. As such a method, for example, an adhesive layer composed of an adhesive formed from an adhesive composition may be provided on the surface of the polarizing film (or the surface of the anchor layer if an anchor layer is provided on the polarizing film). For example, the adhesive composition is applied to a separator or the like that has been subjected to a peeling treatment, and if necessary, heated or dried to form the adhesive layer, and then the adhesive layer is transferred to the surface of the polarizing film (or the surface of the anchor layer if an anchor layer is provided on the polarizing film) (transfer method), or the adhesive composition is applied to the surface of the polarizing film (or the surface of the anchor layer if an anchor layer is provided on the polarizing film), and if necessary, heated, irradiated with active energy rays (such as ultraviolet rays), dried, etc. to form the adhesive layer (direct method).

[0020] As the conditions for the above heating and drying, any appropriate conditions can be adopted without impairing the effects of the present invention. As the above coating method, for example, methods such as 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, a die coater, etc. can be mentioned.

[0021] ≪≪2. Adhesive layer and adhesive composition≫≫ The adhesive layer may be only one layer or two or more layers. Typically, the adhesive layer is one layer.

[0022] In one embodiment of the thickness of the adhesive layer, in terms of more effectively expressing the effects of the present invention, it is preferably 0.5 μm to 200 μm, more preferably 1 μm to 150 μm, still more preferably 5 μm to 100 μm, and particularly preferably 10 μm to 80 μm.

[0023] Another embodiment of the thickness of the adhesive layer is preferably 0.5 μm to 100 μm, more preferably 1 μm to 50 μm, still more preferably 2 μm to 40 μm, and particularly preferably 3 μm to 30 μm in terms of more effectively expressing the effects of the present invention.

[0024] The adhesive layer is composed of an adhesive formed from an adhesive composition.

[0025] The adhesive composition contains, as a base polymer, at least a part of a polymer (typically a crosslinked polymer) that constitutes a polymer (raw material monomer component) that is finally contained as a main component in the adhesive layer. However, the crosslinking agent is not included in the raw material monomer component.

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

[0027] When the base polymer is a part of the polymers of the raw material monomer components, this base polymer may be referred to as a "partial polymer". The partial polymer may typically be in a syrup-like (viscous liquid) state mixed with the raw material monomer components (unreacted monomer components) that have not been consumed in the partial polymerization. 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, may be 1% to 70% by weight, may be 3% to 60% by weight, may be 3% to 50% by weight, may be 5% to 40% by weight, or may be 5% to 35% by weight.

[0028] The pressure-sensitive adhesive composition contains a base polymer and an ionic compound. The base polymer may be only one kind or two or more kinds. The ionic compound may be only one kind or two or more kinds.

[0029] As the base polymer, any appropriate base polymer can be adopted as long as the effects of the present invention are not impaired. Preferably, the base polymer includes at least one selected from acrylic polymers, polyols, and urethane prepolymers.

[0030] As embodiments where the base polymer is an acrylic polymer, typically, there are two embodiments: an embodiment where the base polymer is acrylic polymer (A) and an embodiment where the base polymer is acrylic polymer (B). Acrylic polymer (A) and acrylic polymer (B) will be described in detail later.

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

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

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

[0034] When the base polymer is in the form of 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] In general, as urethane polymers, there are known "prepolymer-type urethane polymers" produced by reacting urethane prepolymers with polyfunctional isocyanate compounds, and "one-shot type urethane polymers" produced by directly reacting polyols with polyfunctional isocyanate compounds without using urethane prepolymers. Urethane prepolymers are typically obtained by reacting polyols with polyfunctional isocyanate compounds 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 type urethane polymer. The one-shot type urethane polymer may be only one type or two or more types. The one-shot type 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 type urethane polymer, the urethane-based pressure-sensitive adhesive composition forming 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 adhesive (D) is typically a prepolymer-type urethane polymer. The prepolymer-type urethane polymer may be only one type or 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 adhesive composition forming the urethane-based adhesive typically contains a urethane prepolymer as a base polymer.

[0038] The content ratio of the base polymer in the adhesive composition can adopt any appropriate content ratio within a range that does not impair the effects of the present invention, depending on the type of the base polymer used, the type of the ionic compound, etc. The content ratio of the base polymer in the adhesive composition is preferably 1 wt% to 99.9 wt% in terms of solid content, and 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%, 75 wt% to 99.9 wt%.

[0039] The content ratio of the ionic compound in the pressure-sensitive adhesive composition can adopt any appropriate content ratio within the range that does not impair the effects of the present invention, depending on the type of base polymer used, the type of ionic compound, etc. In terms of being able to more express the effects of the present invention, the content ratio of the ionic compound in the pressure-sensitive adhesive composition is preferably 0.001 to 3000 parts by weight, more preferably 0.001 to 2000 parts by weight, still more preferably 0.001 to 1000 parts by weight, yet more preferably 0.001 to 500 parts by weight, still yet more preferably 0.001 to 300 parts by weight, even still more preferably 0.001 to 100 parts by weight, even yet still more preferably 0.001 to 50 parts by weight, and most preferably 0.001 to 30 parts by weight, based on 100 parts by weight of the base polymer.

[0040] In one embodiment, the content ratio of the ionic compound in the pressure-sensitive adhesive composition is more preferably 0.001 to 10 parts by weight, still 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, based on 100 parts by weight of the base polymer.

[0041] In another embodiment, the content ratio of the ionic compound in the pressure-sensitive adhesive composition is more preferably 0.001 to 20 parts by weight, still 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, based on 100 parts by weight of the base polymer. This embodiment can be a suitable content ratio for the pressure-sensitive adhesive composition that forms the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer in an optical laminate (i.e., a polarizing film with a pressure-sensitive adhesive layer according to an embodiment of the present invention) including a polarizing film and a pressure-sensitive adhesive layer.

[0042] 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) as described above.

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

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

[0047] ≪2-1. Ionic Compound≫ The pressure-sensitive adhesive composition contains an ionic compound. The ionic compound consists of a cationic species and an anionic species. As such an ionic compound, any suitable ionic compound can be employed as long as the effects of the present invention are not impaired.

[0048] The ionic compound may be an ionic liquid. The ionic liquid 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 anionic species is preferably at least one selected from the group consisting of borate anions and dicyanamide anions. By adopting at least one selected from the group consisting of borate anions and dicyanamide anions as the anionic species, the effects of the present invention can be exhibited.

[0050] Examples of the borate anion include bis(oxalato)borate, bis(mandelato)borate, bis(salicylato)borate, bis(malonato)borate, bis(succinato)borate, bis(glutarato)borate, and bis(adipato)borate. Among them, bis(oxalato)borate represented by the following chemical formula (A) is preferable in terms of more effectively expressing the effects of the present invention.

[0051]

Chemical formula

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

[0053] It is preferable that an oxygen atom is directly bonded to the boron atom in the borate anion. By directly bonding an oxygen atom to the boron atom, the effect of further enhancing the conductivity can be exhibited.

[0054] The dicyanamide anion is an anion represented by (CN)2N - as shown.

[0055] As the cation species, any appropriate cation can be adopted as long as the effects of the present invention are not impaired. In terms of more effectively expressing 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 suitable onium cation can be employed as long as the effects of the present invention are not impaired. In terms of being able to more effectively exhibit the effects of the present invention, such an 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 an ammonium cation (nitrogen-containing onium cation).

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

Chemical formula

[0058] In general formula (1), R a represents a hydrocarbon group having 4 to 20 carbon atoms, which may contain a heteroatom, and R b and R c are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, which may contain a heteroatom. However, when the nitrogen atom contains a double bond, R c is absent.

[0059] In general formula (2), R d represents a hydrocarbon group having 2 to 20 carbon atoms, which may contain a heteroatom, and R e , R f , and R g are 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, and 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 is absent.

[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 the cationic species having a cationic structure represented by the general formula (1) include, for example, 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, 1-octyl-4-methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, 1,1-dimethylpyrrolidinium cation; pyrrolidinium cations such as 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-ethyl-1-heptylpyrrolidinium cation, 1,1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, 1,1-dibutylpyrrolidinium cation; piperidinium cations such as 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, 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, 1,1-dibutylpiperidinium cation;2-Methyl-1-pyrroline cation; 1-Ethyl-2-phenylindole cation; 1,2-Dimethylindole cation; 1-Ethylcarbazole cation; a cation having at least one selected from the group consisting of a vinyl group (CH2=CH-group) and an allyl group (CH2=CH-CH2-group); are mentioned.

[0064] Among these, in terms of further expressing the effects of the present invention, preferably, 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, 1-octyl-4-methylpyridinium cation; pyrrolidinium cations such as 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-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, 1-propyl-1-butylpiperidinium cation; cations in which these cations further have at least one selected from the group consisting of a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group);Examples include, more preferably, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-octyl-4-methylpyridinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-propylpiperidinium cation, and cations having at least one selected from the group consisting of vinyl group (CH2=CH-group) and allyl group (CH2=CH-CH2-group).;

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

[0066] Specific examples of the cationic species having a cationic structure represented by the 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, 1-tetradecyl-3-methylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1-hexyl-2,3-dimethylimidazolium cation and other imidazolium cations; 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-trimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,5-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation and other tetrahydropyrimidinium cations; 1,3-dimethyl-1,4-dihydropyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium cation, 1,2,3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,6-dihydropyrimidinium cation and other dihydropyrimidinium cations; cations having at least one selected from the group consisting of a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group) in addition to these cations; may be mentioned.

[0067] Among these, in terms of further expressing the effects of the present invention, preferably, 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, imidazolium cations such as cations having at least one selected from the group consisting of a vinyl group (CH2=CH-group) and an allyl group (CH2=CH-CH2-group), more preferably, 1-ethyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, cations having 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 the general formula (3) include a pyrazolium cation structure and a pyrazolinium cation structure.

[0069] Specific examples of the cation species having the cation structure represented by the general formula (3) include, for example, pyrazolium cations such as 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation, 1-ethyl-2,3,5-trimethylpyrazolium cation, 1-propyl-2,3,5-trimethylpyrazolium cation, 1-butyl-2,3,5-trimethylpyrazolium cation; pyrazolinium cations such as 1-ethyl-2,3,5-trimethylpyrazolinium cation, 1-propyl-2,3,5-trimethylpyrazolinium cation, 1-butyl-2,3,5-trimethylpyrazolinium cation; cations having at least one selected from the group consisting of a vinyl group (CH2=CH-group) and an allyl group (CH2=CH-CH2-group).

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

[0071] Specific examples of the cation species having a cation structure represented by the 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 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, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation, etc.; Trialkylsulfonium cations such as trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, etc.; Tetraalkylphosphonium cations such as tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation, etc.; Cations having at least one selected from the group consisting of a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group); are included.,

[0072] As the metal cation, any appropriate metal cation can be employed as long as the effects of the present invention are not impaired. In terms of being able to further exhibit the effects of the present invention, such metal cations are preferably alkali metal cations such as Li cation, Na cation, K cation, etc.,

[0073] Examples of the ionic compound include a combination of the cation species described above and at least one anion species selected from the group consisting of a borate anion and a dicyanamide anion. In terms of being able to more effectively exhibit the effects of the present invention, the ionic compound preferably includes an ionic compound composed of a combination of a pyridinium cation and a borate anion, an ionic compound composed of a combination of a pyridinium cation and a dicyanamide anion, an ionic compound composed of a combination of an imidazolium cation and a borate anion, an ionic compound composed of a combination of an imidazolium cation and a dicyanamide anion, an ionic compound composed of a combination of a metal cation and a borate anion, and an ionic compound composed of a combination of a metal cation and a dicyanamide anion. More preferably, they 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] As the ionic compound, commercially available products may be used, or those synthesized by any appropriate method may be used. For example, the ionic liquid may be synthesized by a halide method, a hydroxide method, an acid ester method, a complex formation method, a neutralization method, or the like, as described in "Ionic Liquids - The Cutting Edge 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 of «2-1. Ionic compounds» can be adopted.

[0076] <2-2-a. Acrylic polymer (A)> The acrylic polymer (A) may be a completely polymerized product or a partially polymerized product.

[0077] When the acrylic polymer (A) is a completely polymerized product, the acrylic polymer (A) may typically be 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 the acrylic pressure-sensitive adhesive composition (A) containing the acrylic polymer (A).

[0078] When the acrylic polymer (A) is a partially polymerized product, the acrylic polymer (A) may typically be an acrylic polymer (typically an acrylic partial polymer) prepared by polymerization (typically partial polymerization) using a photoinitiator. 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 ratio of the acrylic polymer (A) in the acrylic pressure-sensitive adhesive composition (A) is preferably 1 wt% to 99.999 wt%, may be 5 wt% to 99.999 wt%, may be 10 wt% to 99.9999 wt%, may be 20 wt% to 99.999 wt%, may be 30 wt% to 99.999 wt%, may be 40 wt% to 99.999 wt%, may be 50 wt% to 99.999 wt%, may be 60 wt% to 99.999 wt%, may be 65 wt% to 99.99 wt%, may be 70 wt% to 99.9 wt%, may be 75 wt% to 99.9 wt%, may be 78 wt% to 99.9 wt% in terms of solid content.

[0080] As the acrylic polymer (A), any suitable acrylic polymer can be adopted as long as the effects of the present invention are not impaired.

[0081] The weight average molecular weight of the acrylic polymer (A) can adopt any suitable weight average molecular weight in terms of more effectively expressing the effects of the present invention. When the acrylic polymer (A) is a completely polymerized product, 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, still more preferably 400,000 to 1,800,000, and particularly preferably 500,000 to 1,500,000. When the acrylic polymer (A) is a partially polymerized product, the weight average molecular weight of the acrylic polymer (A) can adopt any suitable weight average molecular weight according to the polymerization conversion rate.

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

[0083] The above-mentioned "acrylic polymer formed by polymerization from the raw material monomer components" may be an acrylic polymer as a completely polymerized product formed by polymerization of all of the raw material monomer components, or may be an acrylic polymer as a partially polymerized product formed by polymerization of a part of the raw material monomer components.

[0084] Component a and component b may each independently be only one kind or two or more kinds.

[0085] Examples of the alkyl (meth)acrylate (component a) in which the number of carbon atoms of the alkyl group in the alkyl ester moiety is 4 to 12 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, dodecyl (meth)acrylate and the like. Among these, in terms of being able to more effectively exhibit the effects of the present invention, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and n-octyl (meth)acrylate are preferable, and more preferably, n-butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate.

[0086] As the at least one type (component b) selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid, for example, (meth)acrylic acid esters having an OH group such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and (meth)acrylic acid can be mentioned. Among these, in terms of being able to more effectively exhibit the effects of the present invention, preferably, hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate, and (meth)acrylic acid, and more preferably, hydroxyethyl acrylate, hydroxybutyl acrylate, and acrylic acid.

[0087] The raw material monomer component may contain a copolymerizable monomer (component c) other than component a and component b. The copolymerizable monomer (component c) may be only one type or two or more types. Examples of such a copolymerizable monomer (component c) include (meth)acrylic acid alkyl esters having an alkyl group with 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, heterocyclic ring-containing monomers (however, those corresponding to amide group-containing monomers are not included in heterocyclic ring-containing monomers), sulfonic acid group-containing monomers, phosphoric acid 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 having an alkyl group with 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 (e.g., acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride).

[0090] Examples of amide group-containing monomers are compounds that contain an amide group in their structure and also contain 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, N-hydroxyethyl(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, mercaptoethyl(meth)acrylamide, and other (meth)acrylamide-based monomers; N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, (meth)acryloylpyrrolidine, and other N-(meth)acryloyl heterocyclic monomers; N-vinyl-2-pyrrolidone, N-vinyl-ε-caprolactam, and other N-vinyl group-containing lactam-based monomers.

[0091] Examples of amino group-containing monomers 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] Examples of the cyano group-containing monomer include (meth)acrylonitrile.

[0094] Examples of the heterocyclic ring-containing monomer include N-vinylpiperidone, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, vinylpyridine, vinylpyrimidine, and vinyloxazole.

[0095] Examples of the sulfonic acid group-containing monomer include sodium vinyl sulfonate.

[0096] Examples of the phosphate group-containing monomer include 2-hydroxyethylacryloyl phosphate.

[0097] Examples of the imide group-containing monomer include cyclohexyl maleimide and isopropyl maleimide.

[0098] Examples of the isocyanate group-containing monomer include 2-methacryloyloxyethyl isocyanate.

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

[0100] Examples of the aromatic ring-containing (meth)acrylate include 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.

[0101] Examples of the (meth)acrylic acid alkoxyalkyl ester include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxy triethylene glycol (meth)acrylate, methoxy polyethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate.

[0102] Examples of the vinyl ester include vinyl acetate and vinyl propionate.

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

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

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

[0106] As the copolymerizable monomer (component c), in terms of more effectively expressing the effects of the present invention, preferably, (meth)acrylic acid alkyl esters in which the alkyl group of the alkyl ester moiety has 1 to 3 carbon atoms, amide group-containing monomers, heterocyclic ring-containing monomers, aromatic ring-containing (meth)acrylates, and (meth)acrylic acid alkoxyalkyl esters are included. More preferably, amide group-containing monomers, heterocyclic ring-containing monomers, aromatic ring-containing (meth)acrylates, and (meth)acrylic acid alkoxyalkyl esters are included.

[0107] That is, as the component c, in terms of being able to more effectively 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 an alkoxyalkyl (meth)acrylate is mentioned. Therefore, the composition (A), in terms of being able to more effectively exhibit the effects of the present invention, preferably contains 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. 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 an alkoxyalkyl (meth)acrylate.

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

[0109] As the aromatic ring-containing (meth)acrylate, in terms of being able to more effectively exhibit the effects of the present invention, preferably, benzyl (meth)acrylate and phenoxybenzyl (meth)acrylate (for example, m-phenoxybenzyl (meth)acrylate) are mentioned.

[0110] As the alkoxyalkyl (meth)acrylate, in terms of being able to more effectively exhibit the effects of the present invention, preferably, 2-methoxyethyl (meth)acrylate is mentioned.

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

[0112] Examples of the polyfunctional monomer include polyfunctional acrylates (ester compounds of polyhydric alcohols and (meth)acrylic acid, etc.) such as 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, pentaerythritol 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 ratio of the alkyl acrylate ester (component a) in which the carbon number of the alkyl group in the alkyl ester portion is 4 to 12 in the total amount of the raw material monomer components is, from the viewpoint of more effectively expressing 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, still 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, based on the total amount of the raw material monomer components. In one embodiment, the content ratio of the alkyl acrylate ester (component a) in which the carbon number of the alkyl group in the alkyl ester portion is 4 to 12 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, still more preferably 50% by weight to 99% by weight, particularly preferably 60% by weight to 98% by weight. In one embodiment, the content ratio of the alkyl acrylate ester (component a) in which the carbon number of the alkyl group in the alkyl ester portion is 4 to 12 in the total amount of the raw material monomer components is still 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 ratio 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 the raw material monomer components is, from the viewpoint of more effectively expressing the effects of the present invention, for example, 0.1% by weight or more, preferably 0.1% by weight to 20% by weight, more preferably 0.2% by weight to 10% by weight, still more preferably 0.2% by weight to 5% by weight, and particularly preferably 0.3% by weight to 1% by weight, based on the total amount of the raw material monomer components. In one embodiment, the content ratio 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 the raw material monomer components is, for example, 0.1% by weight or more, preferably 0.2% by weight to 30% by weight, more preferably 0.3% by weight to 20% by weight, still more preferably 0.4% by weight to 15% by weight, and particularly preferably 0.5% by weight to 12% by weight.

[0115] In terms of more effectively expressing the effects of the present invention, the content ratio 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, still more preferably 13% to 75% by weight, and particularly preferably 15% to 70% by weight, based on the total amount of the raw material monomer components. In one embodiment, the content ratio 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, still 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), a (meth)acrylic acid alkyl ester in which the alkyl group of the alkyl ester moiety has 1 to 3 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. When the raw material monomer components contain such a (meth)acrylic acid alkyl ester in which the alkyl group of the alkyl ester moiety has 1 to 3 carbon atoms, the content ratio of such a (meth)acrylic acid alkyl ester 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, still more preferably 0.5% to 30% by weight, and particularly preferably 1% to 20% by weight, based on 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 aforementioned (meth)acrylamide-based monomers such as (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-hydroxyethyl(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, mercaptoethyl(meth)acrylamide; N-(meth)acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, (meth)acryloylpyrrolidine; N-vinyl group-containing lactam-based monomers such as N-vinyl-2-pyrrolidone, N-vinyl-ε-caprolactam; and other amide group-containing monomers may be included. When the raw material monomer component includes such amide group-containing monomers, the content ratio of such amide group-containing monomers in the total amount of the raw material monomer component is preferably 0.1% by weight or more, more preferably 0.1% by weight to 30% by weight, still 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 with respect to the total amount of the raw material monomer component.

[0118] In one embodiment, the raw material monomer component may contain, as the 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 component contains such an aromatic ring-containing (meth)acrylate, the content ratio of such an aromatic ring-containing (meth)acrylate in the total amount of the raw material monomer component is preferably 0.1% by weight or more, more preferably 1% to 30% by weight, still more preferably 5% to 25% by weight, and particularly preferably 10% to 20% by weight based on the total amount of the raw material monomer component.

[0119] In one embodiment, the raw material monomer component may contain, as the copolymerizable monomer (component c), the aforementioned alkoxyalkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxy triethylene glycol (meth)acrylate, methoxy polyethylene 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 component contains such an alkoxyalkyl (meth)acrylate, the content ratio of such an alkoxyalkyl (meth)acrylate in the total amount of the raw material monomer component is preferably 0.1% by weight or more, more preferably 0.1% to 70% by weight, still 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 component.

[0120] In terms of being able to more fully exhibit the effects of the present invention, one preferred embodiment of the raw material monomer component includes an alkyl (meth)acrylate (component a) in which the alkyl group of the alkyl ester moiety has 4 to 12 carbon atoms, at least one selected from the group consisting of a (meth)acrylate having an OH group and (meth)acrylic acid (component b), and 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.

[0121] A composition containing all or part of the raw material monomer component, which is subjected to a 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] Depending on the type of polymerization reaction, a thermal polymerization initiator, a photo-polymerization initiator (photoinitiator), etc. may be employed as the polymerization initiator. The polymerization initiator may be only one type or two or more types.

[0123] The thermal polymerization initiator is preferably employed when obtaining the acrylic polymer (A) by solution polymerization. Examples of such a thermal polymerization initiator include an azo-based polymerization initiator, a peroxide-based polymerization initiator (e.g., dibenzoyl peroxide, tert-butyl permaleate), and a redox-based polymerization initiator. Among these thermal polymerization initiators, the azo-based initiator disclosed in JP-A-2002-69411 is particularly preferred. Such an azo-based polymerization initiator is preferred in that the decomposition product of the polymerization initiator is less likely to remain in the acrylic polymer as a cause of the generation of heat-generated gas (outgas). Examples of the azo-based polymerization initiator 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-methylpropionic acid) dimethyl, and 4,4'-azobis-4-cyanovaleric acid.

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

[0125] Specific examples of the benzoin ether-based photoinitiators include, for example, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one (as a commercial product, for example, trade name "OMNIRAD651", manufactured by IGM Resins B.V.), anisole methyl ether, and the like.

[0126] Specific examples of the acetophenone-based photoinitiators include, for example, 1-hydroxycyclohexyl phenyl ketone (as a commercial product, for example, 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 (as a commercial product, for example, trade name "OMNIRAD2959", manufactured by IGM Resins B.V.), 2-hydroxy-2-methyl-1-phenyl-propan-1-one, methoxyacetophenone, and the like.

[0127] Examples of α-ketol-based photoinitiators include, specifically, 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)-phenyl]-2-hydroxy-2-methylpropan-1-one, and the like.

[0128] Examples of aromatic sulfonyl chloride-based photoinitiators include, specifically, 2-naphthalenesulfonyl chloride and the like.

[0129] Examples of photoactive oxime-based photoinitiators include, specifically, 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime and the like.

[0130] Examples of benzoin-based photoinitiators include, specifically, benzoin and the like.

[0131] Examples of benzyl-based photoinitiators include, specifically, benzyl and the like.

[0132] Examples of benzophenone-based photoinitiators include, specifically, benzophenone, benzoyl benzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, and the like.

[0133] Examples of ketal-based photoinitiators include, specifically, benzyldimethyl ketal and the like.

[0134] Examples of thioxanthone-based photoinitiators include, specifically, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, and the like.

[0135] As acylphosphine-based photoinitiators, specifically, for example, 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)-t-butylphosphine 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,(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-dimethoxybenzoyl-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, etc. may be mentioned.,

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

[0137] As the chain transfer agent, a known chain transfer agent can be adopted. The chain transfer agent may be only one kind or two or more kinds.

[0138] The amount of the chain transfer agent used can be any appropriate amount as long as the effects of the present invention are not impaired. Such an amount is, for example, preferably 0.01% by weight to 15% by weight based on the total or partial amount of the raw material monomer components used in the polymerization reaction for obtaining the acrylic polymer (A).

[0139] As the solvent, any appropriate solvent can be employed as long as the effects of the present invention are not impaired. Examples of such solvents include 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; ketones such as methyl ethyl ketone and methyl isobutyl ketone; and other organic solvents. The solvent may be only one kind or two or more kinds. As the amount of the solvent used, any appropriate amount can be adopted as long as the effects of the present invention are not impaired.

[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 the polymerization method that can be adopted for the polymerization of the acrylic polymer (A) include solution polymerization, emulsion polymerization, bulk polymerization, and active energy ray polymerization by irradiation such as ultraviolet rays. Typically, solution polymerization and photopolymerization are used.

[0141] As the supply method of the raw material monomer components when performing solution polymerization, a batch charging method of supplying the total amount of the raw material monomer components at once, a continuous supply (dropping) method, a divided supply (dropping) method, etc. can be appropriately adopted. The polymerization temperature can be appropriately selected according to the types of the raw material monomer components, the solvent, the type of the polymerization initiator, etc., and is preferably 20°C to 160°C, more preferably 30°C to 140°C, still more preferably 40°C to 120°C, and particularly preferably 50°C to 100°C. The polymerization time can be appropriately selected according to the types of the raw material monomer components, the solvent, the type of the polymerization initiator, 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 the effects of the present invention are not impaired. Photopolymerization can be carried out, for example, by irradiating ultraviolet rays to a composition containing all or part of the raw material monomer components to be subjected to the polymerization reaction for obtaining the acrylic polymer (A). In order to obtain the acrylic polymer (A) as a partial polymer, for example, the irradiation of ultraviolet rays can be appropriately adjusted.

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

[0144] As one embodiment of the crosslinking agent, 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 can be mentioned. Among these, in terms of being able to more effectively exhibit the effects of the present invention, it is preferably at least one selected from the group consisting of polyfunctional isocyanate-based crosslinking agents, epoxy-based crosslinking agents, and peroxide-based crosslinking agents. Such a crosslinking agent may be only one type or two or more types. The crosslinking agent according to this embodiment is suitable when the acrylic polymer (A) is a completely polymerized product. In particular, 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 the acrylic pressure-sensitive adhesive composition (A) containing the acrylic polymer (A), it is suitable. Of course, the crosslinking agent according to this embodiment may also be used when the acrylic polymer (A) is a partially polymerized product.

[0145] As the polyfunctional isocyanate crosslinking agent, a compound having two or more isocyanate groups (including isocyanate regenerable polar groups in which the isocyanate groups are temporarily protected by a blocking agent or oligomerization, etc.) in one molecule can be employed. Specific examples of the polyfunctional isocyanate crosslinking agent include, for example, 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; isocyanate adducts such as trimethylolpropane / tolylene diisocyanate trimer adduct (for example, trade name: Takenate D101E, manufactured by Mitsui Chemicals, Inc.), trimethylolpropane / hexamethylene diisocyanate trimer adduct (for example, trade name: Coronate HL, manufactured by Tosoh Corporation), and isocyanurate form of hexamethylene diisocyanate (for example, trade name: Coronate HX, manufactured by Tosoh Corporation); trimethylolpropane adducts of xylylene diisocyanate (for example, trade name: Takenate D110N, manufactured by Mitsui Chemicals, Inc.), trimethylolpropane adducts of xylylene diisocyanate (for example, trade name: Takenate D120N, manufactured by Mitsui Chemicals, Inc.), trimethylolpropane adducts of isophorone diisocyanate (for example, trade name: Takenate D140N, manufactured by Mitsui Chemicals, Inc.), trimethylolpropane adducts of hexamethylene diisocyanate (for example, trade name: Takenate D160N, manufactured by Mitsui Chemicals, Inc.); polyether polyisocyanates, polyester polyisocyanates, and adducts thereof with various polyols; polyisocyanates polyfunctionalized with isocyanurate bonds, burette bonds, allophanate bonds, etc.; may be mentioned.

[0146] Examples of epoxy crosslinking agents (polyfunctional epoxy compounds) include N,N,N’,N’-tetraglycidyl-m-xylenediamine, 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, 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, resorcin diglycidyl ether, bisphenol-S-diglycidyl ether, and other epoxy resins having two or more epoxy groups in the molecule. Examples of epoxy crosslinking agents also include commercially available products such as the product named "Tetrad C" (manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0147] Examples of peroxide crosslinking agents include dibenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, di-t-butyl peroxy-3,3,5-trimethylcyclohexane, t-butyl hydroperoxide, t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexin-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-butyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, t-butyl peroxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, t-butyl peroxy-2-ethylhexyl carbonate, t-amyl peroxyisopropyl carbonate, 3,5,5-trimethylhexanoyl peroxide, t-butyl peroxy-2-hexanoate rate, t-butyl peroxypivalate, t-hexyl peroxypivalate. Examples of commercially available peroxides include the "Niper BMT" series and "Niper BW" series manufactured by NOF Corporation, Japan.

[0148] As another embodiment of the crosslinking agent, there may be mentioned the polyfunctional monomers described in the above item <2-2-a. Acrylic polymer (A)>. Such a crosslinking agent may be only one kind or two or more kinds. The crosslinking agent according to this embodiment is suitable when the acrylic polymer (A) is a partial polymer. In particular, the acrylic polymer (A) is an acrylic polymer (typically, an acrylic partial polymer) prepared by polymerization (typically, partial polymerization) using a photoinitiator, and the acrylic pressure-sensitive adhesive (A) is suitable when it 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 be used when the acrylic polymer (A) is a completely polymerized product.

[0149] The content of the crosslinking agent in the acrylic pressure-sensitive adhesive composition (A) can be any appropriate content within a range that does not impair the effects of the present invention. Such a content is preferably 0.001% by weight to 20 parts by weight, may be 0.005 parts by weight to 20 parts by weight, may be 0.01 parts by weight to 10 parts by weight, may be 0.05 parts by weight to 5 parts by weight, may be 0.05 parts by weight to 3 parts by weight, may be 0.05 parts by weight to 1 part by weight, may be 0.05 parts by weight to 0.5 part by weight, and may be 0.05 parts by weight to 0.25 part by weight, in terms of more effectively expressing the effects of the present invention, based on 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 only one kind or two or more kinds.

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

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

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

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

[0155] Specific examples of the (meth)acrylic acid ester having a cyclic structure in the molecule include, for example, (meth)acrylic acid cycloalkyl esters such as cyclohexyl (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; (meth)acrylic acid esters having a tricyclic or higher aliphatic hydrocarbon ring such as dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, and 2-ethyl-2-adamantyl (meth)acrylate; (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. Among them, in terms of more effectively expressing the effects of the present invention, cyclohexyl acrylate, cyclohexyl methacrylate, dicyclopentanyl acrylate, and dicyclopentanyl methacrylate are preferably mentioned.

[0156] The content ratio of the (meth)acrylate having a cyclic structure in the molecule to the total amount of the monomer components constituting the acrylic oligomer is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 99% by weight, still 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 (for example, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride). Such carboxyl group-containing monomers may be only one kind or two or more kinds.

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

[0159] The monomer components constituting the acrylic oligomer may contain other monomers. Such other monomers may be only one kind or two or more kinds.

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

[0161] Examples of other monomers include (meth)acrylic acid alkyl esters 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; 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; (meth)acrylic acid alkoxyalkyl 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 also 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] Other monomers include nitrogen atom-containing monomers (for example, aminoalkyl (meth)acrylates such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate; (N-substituted) amide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hydroxy(meth)acrylamide; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate, etc.).

[0164] As the acrylic oligomer, in terms of being able to more effectively exhibit the effects of the present invention, it is preferably formed by polymerization from a composition containing a monomer component having a (meth)acrylate having a cyclic structure in the molecule as an essential component. Such a composition may contain any appropriate other components in addition to the monomer component. Examples of such other components include, for example, 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.), anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foils, ultraviolet absorbers, antioxidants, light stabilizers, plasticizers, softeners, surfactants, antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, catalysts.

[0165] Each of the polymerization initiator, chain transfer agent, and solvent may refer to the description in the section of <2-2-a. Acrylic polymer (A)>.

[0166] The acrylic oligomer can be prepared by any suitable polymerization method as long as the effects of the present invention are not impaired. Examples of the polymerization method that can be employed for the polymerization of the acrylic oligomer include, for example, solution polymerization, emulsion polymerization, bulk polymerization, and active energy ray polymerization by irradiation with ultraviolet rays or the like. Typically, solution polymerization and active energy ray polymerization are used, and preferably, solution polymerization is used. As the monomer supply method when performing solution polymerization, a batch charging method in which the total 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 according to the types of the monomers and solvents used, the type of the polymerization initiator, etc., and is preferably 20°C to 160°C, more preferably 30°C to 140°C, still more preferably 40°C to 120°C, and particularly preferably 50°C to 100°C.

[0167] The amount of the polymerization initiator used can be any appropriate amount as long as the effects of the present invention are not impaired. Examples of such an amount of the polymerization initiator used include, for example, preferably 0.01% by weight 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 can be any appropriate amount as long as the effects of the present invention are not impaired. Examples of such an amount used include, for example, preferably 0.01% by weight 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-based additives, anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foils, ultraviolet 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 ratio of other components in the acrylic pressure-sensitive adhesive composition (A) is preferably 0 parts by weight to 30 parts by weight, more preferably 0 parts by weight to 20 parts by weight, still more preferably 0 parts by weight to 10 parts by weight, based on 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 the 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 of ≪2-1. Ionic Compounds≫ can be adopted.

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

[0173] As the acrylic polymer (B), any appropriate acrylic polymer can be employed as long as the effects of the present invention are not impaired. As such an acrylic polymer (B), for example, the acrylic polymer (A) described in the section of <2-2-a. Acrylic polymer (A)> can be adopted.

[0174] <2-3-b. Crosslinking agent> The acrylic pressure-sensitive adhesive composition (B) may contain a crosslinking agent. By using a crosslinking agent, the effects of the present invention can be more effectively exhibited. The crosslinking agent may be only one kind or two or more kinds.

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

[0176] The content ratio of the crosslinking agent in the acrylic pressure-sensitive adhesive composition (B) can be any appropriate content ratio as long as the effects of the present invention are not impaired. Such a content ratio is preferably 0.005 parts by weight to 20 parts by weight, more preferably 0.01 parts by weight to 10 parts by weight, still more preferably 0.01 parts by weight to 5 parts by weight, particularly preferably 0.05 parts by weight to 4 parts by weight, and most preferably 0.08 parts by weight to 3 parts by weight, in terms of being able to more effectively exhibit the effects of the present invention, based on 100 parts by weight of the base polymer (the solid content (100 parts by weight) 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 only one kind or two or more kinds.

[0178] As the crosslinking catalyst, any appropriate crosslinking catalyst can be adopted as long as the effects of the present invention are not impaired. Examples of the crosslinking catalyst include metal-based crosslinking catalysts such as tetra-n-butyl titanate, tetraisopropyl titanate, zirconium tetraacetylacetonate, iron diacetylacetonate, butyltin oxide, and dioctyltin dilaurate.

[0179] The content ratio of the crosslinking catalyst in the acrylic pressure-sensitive adhesive composition (B) can adopt any appropriate content ratio as long as the effects of the present invention are not impaired. In terms of more effectively expressing the effects of the present invention, such a content ratio is preferably 0.0001 parts by weight to 1 part by weight with respect to 100 parts by weight of the base polymer (the solid content (100 parts by weight) of the acrylic polymer (B)).

[0180] <2-3-d. Photoinitiator> The acrylic pressure-sensitive adhesive composition (B) may contain a photoinitiator. The photoinitiator may be only one type or two or more types.

[0181] Examples of the photoinitiator include photocurable monomers and photocurable oligomers. As the photoinitiator, a compound having two or more ethylenically unsaturated bonds in one molecule is preferable.

[0182] The photoinitiator is preferably a compound that shows compatibility with the base polymer. In this regard, those that are liquid at room temperature are preferable. Also, the compatibility between the base polymer and the photoinitiator depends on the molecular weight of the compound. The smaller the molecular weight, the higher the compatibility with the base polymer tends to be. Therefore, the molecular weight of the photoinitiator is preferably 1500 or less, more preferably 1000 or less.

[0183] As the photoinitiator, polyfunctional (meth)acrylates are preferably used. Examples of the polyfunctional (meth)acrylates 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, pentaerythritol di(meth)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, and isoprene (meth)acrylate.

[0184] The functional group equivalent weight (g / eq) of the photoinitiator 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 ratio of the photoinitiator in the acrylic pressure-sensitive adhesive composition (B) can be any appropriate content ratio as long as the effects of the present invention are not impaired. In terms of more effectively expressing the effects of the present invention, such a content ratio is preferably 1 part by weight to 100 parts by weight, more preferably 2 parts by weight to 70 parts by weight, still more preferably 3 parts by weight to 50 parts by weight, particularly preferably 4 parts by weight to 40 parts by weight, and most preferably 5 parts by weight to 35 parts by weight, based on 100 parts by weight of the base polymer (the solid content (100 parts by weight) of the acrylic polymer (B)).

[0186] <2-3-e. Photoinitiator> The acrylic pressure-sensitive adhesive composition (B) may contain a photoinitiator. The photoinitiator may be only one kind or two or more kinds.

[0187] As the photoinitiator, any suitable photoinitiator can be employed as long as the effects of the present invention are not impaired. Examples of such photoinitiators include the photoinitiators described in the item <2-2-a. Acrylic polymer (A)>.

[0188] The content ratio of the photoinitiator in the acrylic pressure-sensitive adhesive composition (B) can be any suitable content ratio as long as the effects of the present invention are not impaired. Such a content ratio is preferably 0.02 parts by weight to 10 parts by weight, more preferably 0.05 parts by weight to 5 parts by weight, based on 100 parts by weight of the base polymer (the solid content (100 parts by weight) of the acrylic polymer (B)), in terms of more effectively expressing the effects of the present invention.

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

[0190] The content ratio of the other components in the acrylic pressure-sensitive adhesive composition (B) is preferably 0% by weight to 40 parts by weight, more preferably 0% by weight to 30 parts by weight, and still more preferably 0% by weight to 20 parts by weight, based on 100 parts by weight of the base polymer (the solid content (100 parts by weight) 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 item ≪2-1. Ionic compound≫ can be employed.

[0192] <2-4-a. Polyol> As the polyol as the base polymer, any suitable polyol can be employed as long as it can react directly with a polyfunctional isocyanate compound to produce a "one-shot type urethane polymer" without impairing the effects of the present invention. Examples of such a polyol include the polyol as the base polymer described in JP-A-2023-167113, and the description related to the polyol as the base polymer described in JP-A-2023-167113 can be incorporated herein as the description of the above polyol.

[0193] <2-4-b. Polyfunctional isocyanate compound> The urethane-based adhesive composition (C) may contain a polyfunctional isocyanate compound. By using a polyfunctional isocyanate compound, the effects of the present invention can be more effectively expressed. The polyfunctional isocyanate compound may be only one kind or two or more kinds.

[0194] As the polyfunctional isocyanate compound, any suitable polyfunctional isocyanate compound can be employed as long as it can react directly with a polyol to produce a "one-shot type urethane polymer" without impairing the effects of the present invention. Examples of such a polyfunctional isocyanate compound include the polyfunctional isocyanate compound described in JP-A-2023-167113, and the description related to the polyfunctional isocyanate compound described in JP-A-2023-167113 can be incorporated herein as the description of the above polyfunctional isocyanate compound.

[0195] <2-4-c. Other components> The urethane-based adhesive composition (C) may contain any suitable 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 of <2-2-d. Other components> can be employed.

[0196] The content ratio of other components in the urethane-based pressure-sensitive adhesive composition (C) is preferably 0 parts by weight to 40 parts by weight, more preferably 0 parts by weight to 30 parts by weight, and still more preferably 0 parts by weight to 20 parts by weight, based on 100 parts by weight of the polyol 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 of ≪2-1. Ionic compounds≫ can be adopted.

[0198] <2-5-a. Urethane prepolymer> As the urethane prepolymer as the base polymer, any suitable urethane prepolymer can be adopted as long as it can react with a polyfunctional isocyanate compound to produce a "prepolymer type urethane polymer" without impairing the effects of the present invention. Examples of such urethane prepolymers include the urethane prepolymer as the base polymer described in JP-A-2023-167112, and the description related to the urethane prepolymer as the base polymer described in JP-A-2023-167112 can be incorporated herein as the description of the above urethane prepolymer.

[0199] <2-5-b. Polyfunctional isocyanate compound> The urethane-based pressure-sensitive adhesive composition (D) may contain a polyfunctional isocyanate compound. By using the polyfunctional isocyanate compound, the effects of the present invention can be more effectively exhibited. The polyfunctional isocyanate compound may be only one kind or two or more kinds.

[0200] As the polyfunctional isocyanate compound, any suitable polyfunctional isocyanate compound can be employed as long as it does not impair the effects of the present invention, provided that it can react with the urethane prepolymer to produce a "prepolymer type urethane polymer". Examples of such polyfunctional isocyanate compounds include the polyfunctional isocyanate compounds described in JP-A-2023-167112, and the explanations related to the polyfunctional isocyanate compounds described in JP-A-2023-167112 can be incorporated herein as the explanations of the above polyfunctional isocyanate compounds.

[0201] <2-5-c. Other components> The urethane-based pressure-sensitive adhesive composition (D) may contain any suitable other components as long as it does not impair the effects of the present invention. As such other components, the other components described in the section <2-2-d. Other components> can be employed.

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

[0203] ≪≪3. Polarizing film≫≫ The polarizing film includes at least a polarizer and a transparent protective film. In FIG. 1, the polarizer may be directly laminated on the adhesive layer 20 or laminated via the transparent protective film.

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

[0205] As the polarizer, any appropriate polarizer can be adopted as long as the effects of the present invention are not impaired. Examples of such polarizers include polarizers composed of resin films. The resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

[0206] Specific examples of polarizers composed of a single-layer resin film include those obtained by subjecting a PVA-based resin film to a dyeing treatment with iodine and a stretching treatment (typically, uniaxial stretching). The dyeing with iodine is performed, for example, by immersing the PVA-based resin film in an iodine aqueous solution. The stretching magnification of the stretching is preferably 3 to 7 times. The stretching may be performed after the dyeing treatment or during the dyeing. Also, it may be dyed after stretching. If necessary, the PVA-based resin film is subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, etc. For example, by immersing the PVA-based resin film in water and washing it before dyeing, not only can the dirt on the surface of the PVA-based resin film and the blocking inhibitor be washed away, but also the PVA-based resin film can be swollen to prevent uneven dyeing and the like.

[0207] Specific examples of a polarizer 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 formed by coating on the resin substrate. A polarizer composed of a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate can be produced, for example, by applying a PVA-based resin solution to the resin substrate and drying it to form a PVA-based resin layer on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer, and stretching and dyeing the laminate to make the PVA-based resin layer a polarizer. In a preferred embodiment, a PVA-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching may typically include immersing the laminate in an aqueous boric acid solution and stretching it. Further, stretching may further include, if necessary, air stretching the laminate at a high temperature (e.g., 95 °C or higher) before stretching in the aqueous boric acid solution. In addition, in a preferred embodiment, the laminate is subjected to a drying shrinkage treatment in which it is heated while being conveyed in the longitudinal direction to shrink by 2% or more in the width direction. Typically, an air-assisted stretching treatment, a dyeing treatment, a stretching treatment in water, and a drying shrinkage treatment are performed on the laminate in this order. By introducing the assisted stretching, even when PVA is applied on a thermoplastic resin, it becomes possible to enhance the crystallinity of PVA and achieve high optical properties. At the same time, by enhancing the orientation of PVA in advance, problems such as a decrease in the orientation of PVA and dissolution when immersed in water in the subsequent dyeing process and stretching process can be prevented, and high optical properties can be achieved. Further, when the PVA-based resin layer is immersed in a liquid, the disturbance of the orientation of polyvinyl alcohol molecules and the decrease in the orientation can be suppressed as compared with the case where the PVA-based resin layer does not contain a halide. Thereby, the optical properties of the polarizer obtained through treatment steps such as a dyeing treatment and a stretching treatment in water, in which the laminate is immersed in a liquid, can be improved. Furthermore, by shrinking the laminate in the width direction by the drying shrinkage treatment, the optical properties can be improved.The obtained resin substrate / polarizer laminate may be used as it is (i.e., the resin substrate may be used as the protective layer of the polarizer), or the resin substrate may be peeled off from the resin substrate / polarizer laminate, and any appropriate protective layer according to the purpose may be laminated on the peeled surface and used. Details of such a method for manufacturing a polarizer are described, for example, in JP-A-2012-73580 and Japanese Patent No. 6470455. The entire descriptions 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 can be any appropriate thickness as long as the effects of the present invention are not impaired. In terms of being able to more manifest 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, still more preferably 1 μm to 12 μm, particularly preferably 2 μm to 10 μm, and most preferably 3 μm to 8 μm.

[0210] As the transparent protective film, any appropriate transparent protective film can be adopted as long as the effects of the present invention are not impaired. Such a transparent protective film preferably has a moisture permeability at 40 °C × 92% RH of 1200 g / (m 2· Examples of the transparent protective film include those having a water vapor transmission rate of 1200 g / (m²·24 h) or less. By adjusting the water vapor transmission rate of the transparent protective film within the above range, for example, it is possible to prevent moisture from entering the pressure-sensitive adhesive layer in contact with the transparent protective film, suppress an increase in the surface resistance value of the pressure-sensitive adhesive layer, and suppress a clouding phenomenon. Further, the lower the water vapor transmission rate of the transparent protective film, the more effectively it is possible to suppress an increase in the surface resistance value of the pressure-sensitive adhesive layer in contact with the transparent protective film. For example, when water that has entered the pressure-sensitive adhesive layer circulates in a humid environment, it is considered that water volatilizes from the side of the polarizing film including the transparent protective film. At this time, a part of the antistatic agent in the pressure-sensitive adhesive layer moves to the side of the polarizing film, so that the antistatic agent on the surface of the pressure-sensitive adhesive layer in contact with the polarizing film decreases, and it is considered that the surface resistance value of the surface of the pressure-sensitive adhesive layer increases. On the other hand, if the water vapor transmission rate of the transparent protective film constituting the polarizing film is low, it is considered that water intrusion into the pressure-sensitive adhesive layer can be prevented and an increase in the surface resistance value of the surface of the pressure-sensitive adhesive layer can be suppressed.

[0211] The water vapor transmission rate of the transparent protective film may be 1000 g / (m 2 ²·24 h) or less, may be 800 g / (m 2 ²·24 h) or less, may be 700 g / (m 2 ²·24 h) or less, may be 600 g / (m 2 ²·24 h) or less, may be 500 g / (m 2 ²·24 h) or less, may be 400 g / (m 2 ²·24 h) or less.

[0212] From the viewpoint of durability and the like, the lower limit value of the water vapor transmission rate of the transparent protective film is preferably 1 g / (m 2 ²·24 h) or more, more preferably 3 g / (m 2 ²·24 h) or more, and particularly preferably 5 g / (m 2 ²·24 h) or more.

[0213] Therefore, the water vapor transmission rate of the transparent protective film is preferably 1 g / (m 2 ²·24 h) to 1200 g / (m 2 ²·24 h), and 1 g / (m 2·24 h) to 1000 g / (m 2 ·24 h) may be sufficient, 1 g / (m 2 ·24 h) to 800 g / (m 2 ·24 h) may be sufficient, 1 g / (m 2 ·24 h) to 700 g / (m 2 ·24 h) may be sufficient, 3 g / (m 2 ·24 h) to 600 g / (m 2 ·24 h) may be sufficient, 3 g / (m 2 ·24 h) to 500 g / (m 2 ·24 h) may be sufficient, 5 g / (m 2 ·24 h) to 400 g / (m 2 ·24 h) may also be sufficient.

[0214] As the material constituting the transparent protective film, any appropriate material can be adopted as long as the effects of the present invention are not impaired. As such a material, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. is used. Specific examples of such thermoplastic resins include, for example, 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 resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. Also included are thermosetting resins or ultraviolet curable resins such as (meth)acrylic-based, urethane-based, (meth)acrylic urethane-based, epoxy-based, silicone-based resins, etc. In addition, for example, glassy polymers such as siloxane-based polymers, and polymer films described in JP-A No. 2001-343529 (WO01 / 37007) are also included. Further, a resin composition 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 can also be used. For example, a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer can be mentioned. As the (meth)acrylic resin, for example, a (meth)acrylic resin having a glutarimide structure is used. The (meth)acrylic resin having a glutarimide structure is 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, 2010-284840. These descriptions are incorporated herein by reference.

[0215] The content ratio of the above 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, still more preferably 60% by weight to 98% by weight, and particularly preferably 70% by weight to 97% by weight.

[0216] Typically, on one side of the polarizer, the above transparent protective film is bonded, for example, by an adhesive layer. On the other side, the above transparent protective film may be bonded, for example, by an adhesive layer, or other thermosetting resins or ultraviolet curable resins may be provided.

[0217] The transparent protective film may contain one or more arbitrary appropriate additives. Examples of such additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0218] The thickness of the transparent protective film can adopt any appropriate thickness as long as the effects of the present invention are not impaired. In terms of better expressing 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, still more preferably 5 μm to 80 μm, and particularly preferably 10 μm to 60 μm. When the transparent protective film is subjected to surface treatment, the thickness of the transparent protective film is the thickness including the thickness of the layer (surface treatment layer) formed by the surface treatment.

[0219] When an adhesive is used for bonding the polarizer and the transparent protective film, as long as the adhesive is optically transparent, any appropriate adhesive can be adopted as long as the effects of the present invention are not impaired. Examples of such adhesives include aqueous adhesives and radical curable adhesives.

[0220] ≪≪4. Adhesive film≫≫ The adhesive layer that can be used in the polarizing film with an adhesive layer according to the embodiment of the present invention can be made into an adhesive film by combining with other layers or the like.

[0221] The pressure-sensitive adhesive film includes a pressure-sensitive adhesive layer that can be used in the polarizing film with a pressure-sensitive adhesive layer according to an embodiment of the present invention. If the pressure-sensitive adhesive film includes a pressure-sensitive adhesive layer that can be used in the polarizing film with a pressure-sensitive adhesive layer according to an embodiment of the present invention, it may include any other appropriate layer. Such other layers may be only one layer or two or more layers. Examples of such other layers include a base material layer, a release liner (which may also be referred to as a release sheet or a separator), an antistatic layer, an easy-adhesion layer, a slip layer, a release layer, a hard coat layer, and an antireflection layer. As a pressure-sensitive adhesive film according to one embodiment, it has a laminated structure in which a base material layer, a pressure-sensitive adhesive layer, and a release liner are laminated in this order, and the release liner is the outermost layer. As a pressure-sensitive adhesive film according to another embodiment, it has a laminated structure in which a base material layer and a pressure-sensitive adhesive layer are laminated in this order, and the pressure-sensitive adhesive layer is the outermost layer. Further, an embodiment in which an antistatic layer is provided on the opposite side of the base material layer from the pressure-sensitive adhesive layer is also a pressure-sensitive adhesive film according to still another embodiment. Also, an easy-adhesion layer may be provided between the base material layer and the pressure-sensitive adhesive layer.

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

[0223] FIG. 2 is a schematic cross-sectional view of the pressure-sensitive adhesive film. In FIG. 2, the pressure-sensitive adhesive film 200 includes a release liner 50, a pressure-sensitive adhesive layer 20, and a base material layer 60. In the embodiment shown in FIG. 2, the release liner 50 and the pressure-sensitive adhesive layer 20 are directly laminated, and the pressure-sensitive adhesive layer 20 and the base material layer 60 are directly laminated. The release liner 50 can be peeled off and used during use. Different from FIG. 1, there may be a case where an easy-adhesion layer or an antistatic layer is provided between the pressure-sensitive adhesive layer 20 and the base material layer 60, or a case where an antistatic layer is provided on the opposite side of the base material layer 60 from the pressure-sensitive adhesive layer 20.

[0224] The base material layer may be only one layer or two or more layers. The base material layer may be stretched.

[0225] The thickness of the base material 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] For the surface of the base material layer where the adhesive layer is not provided, for the purpose of suppressing the generation of static electricity, etc., an antistatic layer containing any appropriate antistatic agent such as a conductive polymer, carbon nanotube, ion-conductive polymer, etc. can be provided. Also, for the purpose of forming a wound body that is easy to unwind, for example, a release treatment can be performed by adding a fatty acid amide, polyethyleneimine, long-chain alkyl-based additive, etc. to the base material layer, or a coat layer composed of any appropriate release agent such as a silicone-based, long-chain alkyl-based, fluorine-based release agent can be provided.

[0227] As the material of the base material layer, any appropriate material can be adopted according to the use. For example, plastics, paper, metal films, non-woven fabrics, etc. can be mentioned. Preferably, it is plastic. That is, the base material layer is preferably a plastic film. The base material layer may be composed of one kind of material or two or more kinds of materials. For example, it may be composed of two or more kinds of plastics.

[0228] Examples of the plastic include polyester resins, polyolefin resins, cyclic polyolefin resins, polyamide resins, polyimide resins, polyether ether ketone, polyether sulfone, polyarylate resins, aramid resins, and the like. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and the like. Examples of the polyolefin resin include homopolymers of olefin monomers, copolymers of olefin monomers, and the like. Specifically, for example, homopolypropylene; propylene copolymers such as block, random, and graft types having an ethylene component as a copolymer component; reactor TPO; ethylene polymers such as low density, high density, linear low density, and ultra-low density; ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-butyl acrylate copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl methacrylate copolymers, and other ethylene copolymers; and the like. Examples of the cyclic polyolefin resin include norbornene resins.

[0229] The base material layer may contain any appropriate additive as needed. Examples of the additives that can be contained in the base material layer include antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, fillers, pigments, and the like. The type, number, and amount of additives that can be contained in the base material layer can be appropriately set according to the purpose.

[0230] Such an adhesive film can exhibit excellent antistatic properties, and the surface resistance value (applied voltage = 100 V, application time 15 seconds) of the surface of the adhesive layer in an environment of 25°C and 50% relative humidity is preferably 1.0×10 12 Ω or less, more preferably 5.0×10 11 Ω or less, still more preferably 1.0×10 11 Ω or less, particularly preferably 5.0×10 10 Ω or less, and most preferably 1.0×10 10is Ω or less. From the viewpoint of antistatic property, the lower limit value of the surface resistance value is preferably as low as possible. However, in reality, for example, it is 1.0×10 6 Ω or more, and may be 1.0×10 7 Ω or more.

[0231] The pressure-sensitive adhesive film can be produced by any suitable method. As such a production method, for example, a known production method of a pressure-sensitive adhesive film including a base material layer and a pressure-sensitive adhesive layer can be adopted.

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

[0233] Examples of the above coating method include methods such as 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, and a roll brush coater.

[0234] The pressure-sensitive adhesive film can be used for any suitable purpose. In terms of effectively expressing the effects of the present invention, the pressure-sensitive adhesive film can preferably be used for at least one selected from the group consisting of a surface protection film and a reinforcing film.

[0235] The peeling force of the pressure-sensitive adhesive film (which may be expressed as an adhesive force) can exhibit any appropriate peeling force depending on the type of the adhesive 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) has a glass-to-glass peel strength described as an evaluation in Examples and Comparative Examples described later, preferably being 0.005 N / 25 mm to 50 N / 25 mm.

[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) has a polyimide-to-polyimide peel strength (1) described as an evaluation in Examples and Comparative Examples described later, preferably being 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 polyimide-to-polyimide peel strength (2) described as an evaluation in Examples and Comparative Examples described later. Before UV irradiation, it is preferably 0.001 N / 25 mm to 1 N / 25 mm, more preferably 0.005 N / 25 mm to 0.8 N / 25 mm, still 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.

[0239] 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 polyimide-to-polyimide peel strength (2) described as an evaluation in Examples and Comparative Examples described later. After UV irradiation, it is preferably 1.5 N / 25 mm or more, more preferably 2 N / 25 mm or more, still 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 value of the polyimide-to-polyimide peel strength (2) after the above UV irradiation, the better.

[0240] The pressure-sensitive adhesive film can be used, for example, as a surface protection film or a reinforcing film, to prevent damage to the surface of optical members or electronic members and to impart impact resistance during processing, assembly, inspection, transportation, etc. in the manufacturing process of optical devices and electronic devices, or as a bonding member for constituting optical members or electronic members, and can be used for any appropriate application.

[0241] ≪≪5. Optical devices and electronic devices≫≫ The optical device according to an embodiment of the present invention includes a polarizing film with an adhesive layer according to an embodiment of the present invention. Examples of such optical devices include image display devices. Representative examples of image display devices include liquid crystal display devices and organic EL display devices.

[0242] Typically, in the manufacturing process of optical devices and electronic devices, the aforementioned pressure-sensitive adhesive film is bonded to the exposed surfaces of optical members or electronic members, etc. to prevent damage to the surface of optical members or electronic members and to impart impact resistance during processing, assembly, inspection, transportation, etc., and can be suitably used for surface protection and reinforcement of optical members and electronic members. That is, such an optical device includes the aforementioned pressure-sensitive adhesive film. Also, such an electronic device includes the aforementioned pressure-sensitive adhesive film.

[0243] ≪≪6. Application to OCA≫≫ The aforementioned ionic compound, like the polarizing film with an adhesive layer according to an embodiment of the present invention, can also be suitably applied to adhesives (for example, OCA (Optical Clear Adhesive)) and anchor layers (undercoat layers) employed inside touch panels and displays, etc. The aforementioned ionic compound, like the polarizing film with an adhesive layer according to an embodiment of the present invention, can be included in an adhesive layer, an anchor layer, or other layers in, for example, an optical laminate including a polarizing film and an adhesive layer or an optical laminate including a polarizing film, an anchor layer, and an adhesive layer (that is, the polarizing film with an adhesive layer according to an embodiment of the present invention), etc., so that, for example, excellent antistatic properties and corrosion resistance can be achieved simultaneously, and in particular, highly reliable antistatic properties and excellent corrosion resistance can be achieved simultaneously.

Example

[0244] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The test and evaluation methods in the examples are as follows. In addition, when "parts" are described, it means "parts by weight" unless otherwise specified, and when "%" is described, it means "% by weight" unless otherwise specified.

[0245] <Measurement of Water Vapor Permeability of Transparent Protective Film> It was measured according to the water vapor permeability test (cup method) of JIS-Z-0208. A transparent protective film cut to a diameter of 60 mm was set in a water vapor permeation cup containing about 15 g of calcium chloride, placed in a constant temperature machine at 40°C and 92% R.H., and after leaving it for 24 hours, the increase in the weight of calcium chloride was measured to obtain the water vapor permeability (g / (m 2 ·24h)).

[0246] <Measurement of Surface Resistivity of Adhesive Layer Surface of Polarizing Film with Adhesive Layer> The release liner was peeled off from the surface of the adhesive layer of the polarizing film with an adhesive layer obtained in the examples and comparative examples, and the surface resistivity of the exposed adhesive layer was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. (initial surface resistivity). In addition, the polarizing film with an adhesive layer obtained in the examples and comparative examples was left in an environment of 65°C and 95% RH for 500 hours, and then the release liner was peeled off from the surface of the adhesive layer, and the surface resistivity of the exposed adhesive layer was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. (surface resistivity after 500 hours at high temperature and high humidity). The surface resistivity was measured under the conditions of an applied voltage of 250 V and a voltage application time of 10 seconds.

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

[0248] <Evaluation Method for Corrosion Resistance of Polarizing Film with Adhesive Layer> The polarizing films with adhesive layers obtained in the examples and comparative examples were cut into a size of 15 mm × 15 mm, the release liners were peeled off, and they were bonded to conductive glass on which an aluminum-based metal layer with a thickness of 0.1 μm was formed on the surface of glass (non-alkali glass) by the sputtering method. This was subjected to an autoclave treatment at 50°C and 5 atm for 15 minutes to obtain a sample for evaluation. The obtained sample for evaluation was left standing in an environment of a temperature of 65°C and a humidity of 95%RH for 500 hours, and the appearance of the aluminum-based metal layer was observed visually and with an optical microscope, and evaluation was carried out based on the following criteria. ◎: No defects. 〇: Defects occur in some places, but at a level where there is no problem in actual use. ×: Defects occur at multiple places, and it is at a level where there is a problem in actual use.

[0249] <Evaluation Method for Corrosion Resistance of Adhesive Film (1)> The adhesive films obtained in the reference examples and reference comparative examples were cut into a size of 30 mm × 80 mm, the release liners were peeled off, and they were pressure-bonded to a 50 mm × 100 mm copper foil with a hand roller to obtain a sample for evaluation. After leaving this sample for evaluation standing in an environment of a temperature of 60°C and a relative humidity of 90% for 24 hours, the surface of the copper foil was observed visually. Evaluation was carried out according to the following criteria. 〇: 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 Adhesive Film (2)> The adhesive films obtained in the reference examples and reference comparative examples were cut into a size of 30 mm × 80 mm, the release liner was peeled off, and they were pressure-bonded to a 50 mm × 100 mm copper foil with a hand roller, and the adhesive layer was photocured by irradiating with ultraviolet light (365 nm LED, integrated light quantity 1000 mJ / cm 2 ). The resulting samples were used as evaluation samples. After leaving these evaluation samples in an environment of 60°C and 90% relative humidity for 24 hours, the surface of the copper foil was visually observed. Evaluation was performed according to the following criteria. 〇: 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] <Peel Strength against Glass> The release liner was peeled off from the surface of the adhesive film cut into a width of 25 mm × a length of 100 mm, and the exposed adhesive layer side was bonded to a glass plate (soda lime glass, manufactured by Matsunami Glass Industry Co., Ltd.) with a 2 kg hand roller in one round trip to prepare test samples. Using a tensile testing machine with the product name "Autograph AG-Xplus HS 6000 mm / min high-speed model (AG-50NX plus)" manufactured by Shimadzu Corporation, the test samples were set on the tensile testing machine, and in an environment of 25°C and 50% relative humidity, at a tensile speed of 300 mm / min and a peel angle of 180 degrees, the load when peeling the adhesive film from the glass plate was measured, and the average load at that time was taken as the peel strength against glass.

[0252] <Peel Strength against Polyimide (1)> A polyimide film with a thickness of 25 μm (UBE Industries' "Upilex 25S") was pasted onto a glass plate via a double-sided adhesive tape (Nitto Denko's "No. 531") to obtain a polyimide film substrate for measurement. The release liner was peeled off from the surface of the adhesive film cut into a width of 25 mm × a length of 100 mm, and the exposed adhesive layer side was pasted onto the polyimide film substrate for measurement with a 2 kg hand roller for one round trip to prepare a test sample. As a tensile testing machine, the product named "Autograph AG-Xplus HS 6000 mm / min high-speed model (AG-50NX plus)" manufactured by Shimadzu Corporation was used. The test sample was set on the tensile testing machine, and in an environment of a temperature of 25 °C and a relative humidity of 50%, the load when peeling the adhesive film from the polyimide film substrate for measurement at a peeling speed of 300 mm / min and a peeling angle of 180 degrees was measured, and the average load at that time was taken as the peel force against polyimide.

[0253] <Peel force against polyimide (2)> A polyimide film with a thickness of 25 μm (UBE Industries' "Upilex 25S") was pasted onto a glass plate via a double-sided adhesive tape (Nitto Denko's "No. 531") to obtain a polyimide film substrate for measurement. The release liner was peeled off from the surface of the adhesive film cut into a width of 25 mm × a length of 100 mm, and the exposed adhesive layer side was pasted onto the polyimide film substrate for measurement with a 2 kg hand roller for one round trip to obtain a test sample before photocuring. Ultraviolet rays (365 nm LED, integrated light quantity 1000 mJ / cm 2 ) were irradiated from the adhesive film side (PET film base material side) of the test sample before photocuring to photocure the adhesive layer, and the resulting sample was used as the test sample after photocuring. Using these respective test samples, as a tensile testing machine, the product named "Autograph AG-Xplus HS 6000 mm / min high-speed model (AG-50NX plus)" manufactured by Shimadzu Corporation was used. The test sample was set on the tensile testing machine, and in an environment of a temperature of 25 °C and a relative humidity of 50%, the load when peeling the adhesive film from the polyimide film substrate for measurement at a peeling speed of 300 mm / min and a peeling angle of 180 degrees was measured, and the average load at that time was taken as the peel force against 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]: Production of Polarizing Film (P1) A long roll of a polyvinyl alcohol (PVA)-based resin film with a thickness of 30 μm (manufactured by Kuraray Co., Ltd., product name "PE3000") was uniaxially stretched 5.9 times in the longitudinal direction using a roll stretching machine while being subjected to swelling, dyeing, crosslinking, and washing treatments, and finally a drying treatment was performed to obtain a polarizer with a thickness of 12 μm. Specifically, in the swelling treatment, the film was stretched 2.2 times while being treated with pure water at 20°C. In the dyeing treatment, the film was stretched 1.4 times while being treated at 30°C in an aqueous solution with the iodine concentration adjusted so that the single transmittance of the resulting polarizer was 45.0%. In the above aqueous solution, the weight ratio of iodine to potassium iodide was 1:7. As the crosslinking treatment, a two-stage crosslinking treatment was adopted. In the first-stage crosslinking treatment, the film was stretched 1.2 times while being treated in an aqueous solution of boric acid / potassium iodide 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-stage crosslinking treatment, the film was stretched 1.6 times while being treated in an aqueous solution of boric acid / potassium iodide 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, an aqueous solution of potassium iodide at 20°C was used. The potassium iodide content of the aqueous solution used for the washing treatment was 2.6%. The drying treatment was carried out under the conditions of 70°C for 5 minutes. A 32-μm-thick TAC-HC film having a hard coat (HC) layer on one side of a triacetyl cellulose (TAC) film was laminated onto one surface of the above polarizer using a PVA-based adhesive. Also, a 13-μm-thick non-stretched cycloolefin polymer (COP) film was laminated onto the other surface of the above polarizer using a PVA-based adhesive to produce a polarizing film (P1) having a structure of a TAC protective layer / PVA polarizer / COP protective layer. A hard coat layer was provided as a surface treatment layer on the surface of the polarizing film (P1) on the TAC protective layer side.

[0256] [Production Example 2]: Production of Polarizing Film (P2) On the other side of the polarizer, a polarizing film (P2) having a configuration of a TAC protective layer / PVA polarizer / CAT protective layer was produced in the same manner as in Production Example 1, except that an acrylic (CAT) film with a thickness of 25 μm was bonded using a PVA-based adhesive instead of the COP film. A hard coat layer is provided as a surface treatment layer on the surface of the TAC protective layer side of this polarizing film (P2).

[0257] [Production Example 3]: Preparation of Acrylic Polymer (1) Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 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) were charged as raw material monomer components. With respect to 100 parts by weight of the charged raw material monomer components, 0.1 part by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added. After introducing nitrogen gas while gently stirring for nitrogen substitution, the liquid temperature in the flask was maintained at around 55°C and a polymerization reaction was carried out for 8 hours to prepare a solution of an acrylic polymer (1) having a weight average molecular weight (Mw) of 1.6 million and Mw / Mn = 3.7.

[0258] [Production Example 4]: Preparation of Acrylic Polymer (2) Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 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) were charged as raw material monomer components. With respect to 100 parts by weight of the charged raw material monomer components, 0.1 part by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added. After introducing nitrogen gas while gently stirring for nitrogen substitution, the liquid temperature in the flask was maintained at around 55°C and a polymerization reaction was carried out for 8 hours to prepare a solution of an acrylic polymer (2) having a weight average molecular weight (Mw) of 1.6 million and Mw / Mn = 3.7.

[0259] [Production Example 5]: Preparation of Acrylic Polymer (3) In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 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) were charged as raw material monomer components. To 100 parts by weight of the charged raw material 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. After introducing nitrogen gas while gently stirring for nitrogen substitution, the polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55°C, and 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) In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 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) were charged as raw material monomer components. To 100 parts by weight of the charged raw material 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. After introducing nitrogen gas while gently stirring for nitrogen substitution, the polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55°C, and a solution of acrylic polymer (4) with a weight average molecular weight (Mw) of 1.7 million and Mw / Mn = 3.5 was prepared.

[0261] [Production Example 7]: Preparation of Acrylic Polymer (5) Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 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) were charged as raw material monomer components. With respect to 100 parts by weight of the charged raw material monomer components, 0.1 part by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added. After introducing nitrogen gas while gently stirring for nitrogen substitution, the polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55°C, and a solution of an acrylic polymer (5) having a weight average molecular weight (Mw) of 1.6 million and Mw / Mn = 3.6 was prepared.

[0262] [Production Example 8]: Preparation of Acrylic Polymer (6) Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 99 parts by weight of butyl acrylate (BA) and 1 part by weight of 4-hydroxybutyl acrylate (4HBA) were charged as raw material monomer components. With respect to 100 parts by weight of the charged raw material monomer components, 0.1 part by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added. After introducing nitrogen gas while gently stirring for nitrogen substitution, the polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55°C, and a solution of an acrylic polymer (6) having a weight average molecular weight (Mw) of 1.6 million and Mw / Mn = 4.0 was prepared.

[0263] [Production Example 9]: Preparation of Acrylic Polymer (7) Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 95.1 parts by weight of butyl acrylate (BA), 4.8 parts by weight of acrylic acid (AA), and 0.1 part by weight of 4-hydroxybutyl acrylate (4HBA) were charged as raw material monomer components. With respect to 100 parts by weight of the charged raw material monomer components, 0.1 part by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 100 parts by weight of ethyl acetate as a solvent were added. After introducing nitrogen gas with gentle stirring for nitrogen replacement, the liquid temperature in the flask was maintained at around 55 °C and a polymerization reaction was carried out for 8 hours to prepare a solution of an acrylic polymer (7) having a weight average molecular weight (Mw) of 2 million and Mw / Mn = 3.9.

[0264] [Production Example 10]: Production of Acrylic Polymer A Into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube, 95 parts by weight of butyl acrylate (BA) and 5 parts by weight of acrylic acid (AA) as monomers, 0.2 part by weight of azobisisobutyronitrile (AIBN) as a polymerization initiator, and 233 parts by weight of ethyl acetate as a solvent were added. Nitrogen gas was passed through and nitrogen replacement was carried out with stirring for about 1 hour. Then, it 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 Into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube, 91 parts by weight of 2-ethylhexyl acrylate (2EHA) and 9 parts by weight of 4-hydroxybutyl acrylate (4HBA) as monomers, 0.2 part by weight of azobisisobutyronitrile (AIBN) as a polymerization initiator, and 233 parts by weight of ethyl acetate as a solvent were added. Nitrogen gas was passed through and nitrogen replacement was carried out with stirring for about 1 hour. Then, it 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 Into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube, 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 were charged. Nitrogen gas was passed through, and nitrogen substitution was carried out for about 1 hour while stirring. Then, it was heated to 60 °C and reacted for 7 hours to obtain a solution of an acrylic polymer C having a weight average molecular weight (Mw) of 600,000.

[0267] [Production Example 13]: Production of Acrylic Oligomer Into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube, 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 were charged. Nitrogen gas was passed through, and nitrogen substitution was carried out for about 1 hour while stirring. Then, it was heated to 70 °C and reacted for 3 hours, and 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 a solution of the acrylic polymer (1) obtained in Production Example 3 (100 parts by weight as the solid content of the acrylic polymer (1)), 0.1 part by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, trade name "Takenate D160N", trimethylolpropane hexamethylene diisocyanate) and 0.3 part by weight of a peroxide-based crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide) as crosslinking agents, and 0.3 part by weight of 1-hexyl-3-methylimidazolium bis(oxalate) borate as an ionic compound were added and uniformly mixed to prepare an adhesive composition (1). On the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, trade name "MRF38") treated with a silicone-based release agent, the above-mentioned pressure-sensitive adhesive composition (1) was applied so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and drying was carried out 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 onto one side of the polarizing film (P1) obtained in Production Example 1 to obtain a polarizing film (1) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0269] [Example 2] The same procedure as in Example 1 was carried out except that 0.3 part by weight of lithium bis(oxalate) borate was used instead of 0.3 part by weight of 1-hexyl-3-methylimidazolium bis(oxalate) borate to obtain a pressure-sensitive adhesive composition (2) and a polarizing film (2) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

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

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

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

[0273] [Example 6] (Preparation of a 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), and 10 parts by weight of 2-methoxyethyl acrylate (MEA) were charged into a four-necked flask, together with 0.2 parts by weight of Omnirad 127D (manufactured by IGM Resins B.V.) as a photoinitiator. 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 irradiation was carried out 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 and 0.3 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate) borate as an ionic compound were added to 100 parts by weight of the obtained monomer syrup (the solid content ratio was 5% by weight), and uniformly mixed to obtain a photocurable pressure-sensitive adhesive composition (6). (Preparation of Polarizing Film with Adhesive Layer (6)) The photocurable pressure-sensitive adhesive composition (6) was applied onto the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, trade name "MRF38") treated with a silicone-based release agent using an applicator 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 arranged such that the release layer was in contact with the coating layer. Next, from the side of the PET film in the first laminate, under the conditions of an illuminance of 3.5 mW / cm 2 and an irradiation time of 460 seconds (integrated light quantity 1600 mJ / cm 2) It was irradiated with light. An LED was used as the light source, and the peak wavelength of the irradiated light was 340 nm. As a result, the coating layer was photocured, and an 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 illuminometer (manufactured by Topcon Technohouse Co., Ltd., UD-T3040T2) at a position near the incident surface of ultraviolet light on the PET film. The obtained adhesive sheet was used as the adhesive layer and transferred to one side of the polarizing film (P1) obtained in Production Example 1 to obtain a polarizing film (6) with an adhesive layer. The results are shown in Table 1.

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

[0275] [Example 8] The same procedure as in Example 7 was carried out except that the amount of 1-hexyl-3-methylimidazolium bis(oxalate) borate used was changed to 6 parts by weight, to obtain an adhesive composition (8) and a polarizing film (8) with an adhesive layer. The results are shown in Table 1.

[0276] [Example 9] The same procedure as in Example 3 was carried out except that the polarizing film (P2) obtained in Production Example 2 was used instead of the polarizing film (P1) obtained in Production Example 1, to obtain an adhesive composition (9) and a polarizing film with an adhesive layer (9). The results are shown in Table 1.

[0277] [Example 10] The same procedure as in Example 9 was carried out 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)), to obtain an adhesive composition (10) and a polarizing film with an adhesive layer (10). The results are shown in Table 1.

[0278] [Example 11] The same procedure as in Example 9 was carried out except that the acrylic polymer (5) obtained in Production Example 7 (100 parts by weight as the solid 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 solid content of the acrylic polymer (1)), to obtain an adhesive composition (11) and a polarizing film with an adhesive layer (11). The results are shown in Table 1.

[0279] [Example 12] To a solution of the acrylic polymer (6) obtained in Production Example 8 (100 parts by weight as the solid content of the acrylic polymer (6)), 0.1 part by weight of an isocyanate-based crosslinking agent (manufactured by Tosoh Corporation, trade name "Takenate D110N", trimethylolpropane / xylene diisocyanate adduct) and 0.3 part by weight of a peroxide-based crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide) as crosslinking agents, and 6 parts by weight of 1-hexyl-3-methylimidazolium bis(oxalate) borate as an ionic compound were added and uniformly mixed to prepare an adhesive composition (12). On the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, trade name "MRF38") treated with a silicone-based release agent, the above-mentioned pressure-sensitive adhesive composition (12) was applied so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and drying was performed 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 polarizing film (P1) obtained in Production Example 1 to obtain a polarizing film (12) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0280] [Example 13] Instead of the solution of the acrylic polymer (6) obtained in Production Example 8 (100 parts by weight as the solid content of the acrylic polymer (6)), the acrylic polymer (7) obtained in Production Example 9 (100 parts by weight as the solid content of the acrylic polymer (7)) was used, and an isocyanate-based crosslinking agent (manufactured by Tosoh Corporation, trade name "Coronate L", trimethylolpropane / toluene diisocyanate adduct): 0.45 parts by weight and a peroxide-based crosslinking agent (manufactured by NOF Corporation, trade name "Niper BMT", benzoyl peroxide): 0.1 part by weight were used as crosslinking agents. Otherwise, the same procedure as in Example 12 was carried out to obtain a pressure-sensitive adhesive composition (13) and a polarizing film (13) with a pressure-sensitive adhesive layer. The results are shown in Table 1.

[0281] [Example 14] To a solution of the acrylic polymer A obtained in Production Example 10 (100 parts by weight as the solid content of the acrylic polymer A), 0.45 part by weight of a tetrafunctional epoxy-based crosslinking agent (manufactured by Mitsubishi Gas Chemical, trade name "Tetrad C") as a crosslinking agent, 0.2 part by weight of zirconium tetraacetylacetonate as a crosslinking catalyst, 30 parts by weight of polyethylene glycol #200 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-200") as a photocuring agent in terms of solid content, 0.3 part by weight of Omnirad651 (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 uniformly mixed to prepare a pressure-sensitive adhesive composition (14). On the release-treated surface of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Corporation, trade name "MRF38") treated with a silicone-based release agent, the above-mentioned pressure-sensitive adhesive composition (14) was applied so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and drying was performed 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 onto one side of the polarizing film (P1) obtained in Production Example 1 to obtain a polarizing film with a pressure-sensitive adhesive layer (14). The results are shown in Table 1.

[0282] [Comparative Example 1] The same procedure as in Example 3 was carried out 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 to obtain a pressure-sensitive adhesive composition (C1) and a polarizing film with a pressure-sensitive adhesive layer (C1). The results are shown in Table 1.

[0283] [Comparative Example 2] The same procedure as in Example 9 was carried out 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 to obtain a pressure-sensitive adhesive composition (C2) and a polarizing film with a pressure-sensitive adhesive layer (C2). The results are shown in Table 1.

[0284] [Comparative Example 3] The same procedure as in Example 12 was carried out 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 to obtain a pressure-sensitive adhesive composition (C3) and a polarizing film with a pressure-sensitive adhesive layer (C3). The results are shown in Table 1.

[0285] [Comparative Example 4] Instead of 1 - hexyl - 3 - methylimidazolium bis(oxalate) borate: 6 parts by weight, 1 - ethyl - 3 - methylimidazolium bis(fluorosulfonyl) imide: 6 parts by weight was used, and the procedure was the same as in Example 13 to obtain an adhesive composition (C4) and a polarizing film with an adhesive layer (C4). The results are shown in Table 1.

[0286] [Table 1]

[0287] [Reference Example 1] To a solution of the acrylic polymer A obtained in Production Example 10 (100 parts by weight as the solid content of the acrylic polymer A), 0.1 part by weight of a tetrafunctional epoxy crosslinking agent (trade name "Tetrad C", manufactured by Mitsubishi Gas Chemical Company) as a crosslinking agent, 25 parts by weight of the acrylic oligomer obtained in Production Example 4 as the solid content, and 0.3 part by weight of 1 - hexyl - 3 - methylimidazolium bis(oxalate) borate as an ionic compound were added and uniformly mixed to prepare an adhesive composition (R1). The above adhesive composition (R1) was applied onto a polyethylene terephthalate film substrate with a thickness of 75 μm 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 polyethylene terephthalate film with a thickness of 25 μm and one surface silicone - release - treated) was bonded to the coated surface of the adhesive composition. Then, aging treatment was carried out for 4 days in an atmosphere at 25°C to allow crosslinking to proceed, and an adhesive layer was fixedly laminated on the polyethylene terephthalate film substrate, and an adhesive film (R1) with a release liner temporarily adhered thereon was obtained. The results are shown in Table 1.

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

[0289] [Table 2]

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

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

[0292] [Reference Example 20] To a solution of acrylic polymer B obtained in Production Example 11 (100 parts by weight as the solid content of acrylic polymer B), 0.1 part by weight of an isocyanurate form of hexamethylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate HX") as a crosslinking agent, 0.02 part 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 terms of solid content, 0.3 part by weight of Omnirad 651 (manufactured by IGM Resins) as a photopolymerization initiator, and 0.2 part by weight of 1-hexyl-3-methylimidazolium bis(oxalate) borate as an ionic compound were added and uniformly mixed to prepare an adhesive composition (R20). The above adhesive composition (R20) was applied onto a polyethylene terephthalate film substrate with a thickness of 75 μm 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 polyethylene terephthalate film with a thickness of 25 μm and one surface silicone release-treated) was laminated onto the coated surface of the adhesive composition. Then, aging treatment was performed for 4 days in an atmosphere at 25°C to allow crosslinking to proceed, and an adhesive sheet was fixedly laminated onto the polyethylene terephthalate film substrate, and an adhesive film (R20) with a release liner temporarily adhered thereon was obtained. The results are shown in Table 3.

[0293] [Reference Examples 21 and 22] Except that the type of acrylic polymer, the type and addition amount of the ionic compound were changed as shown in Table 3, the same procedures as in Reference Example 20 were carried out to obtain adhesive compositions (R21), (R22), and adhesive films (R21), (R22). The results are shown in Table 3.

[0294]

Table 3

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

[0296] [Reference Example 24] For each of the pressure-sensitive adhesive films (R1) to (R22) obtained in Reference Examples 1 to 22, the release liner was peeled off, and the pressure-sensitive adhesive layer side was adhered to a conductive film (manufactured by Nitto Denko Corporation, trade name "Electrysta V270L-TFMP"), which is an electronic member, to obtain an electronic device. [Industrial Applicability]

[0297] The polarizing film with a pressure-sensitive adhesive layer according to an embodiment of the present invention can be used for an optical device such as an image display device. [Explanation of Signs]

[0298] 100 Polarizing film with a pressure-sensitive adhesive layer 10 Polarizing film 20 Pressure-sensitive adhesive layer 30 Anchor layer 40 Surface treatment layer 50 Release liner 60 Base material layer 200 Pressure-sensitive adhesive film

Claims

1. A polarizing film with an adhesive layer, comprising an adhesive layer and a polarizing film, The adhesive layer is composed of an adhesive formed from an adhesive composition, The adhesive composition contains a base polymer and an ionic compound, The ionic compound consists of a cationic species and an anionic species, 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 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, a (meth)acrylate having an OH group, and (meth)acrylic acid. The polarizing film with an adhesive layer according to claim 4.

6. 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. The polarizing film with an adhesive layer according to claim 4.

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 to 30 parts by weight.

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

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