Adhesive composition, adhesive layer, and polarizing plate with adhesive

Abstract

The invention provides an adhesive composition, an adhesive layer and a polarizing plate with an adhesive. The adhesive composition has good adhesive force, antistatic property and metal corrosion resistance. This adhesive composition contains a (meth) acrylic resin (A-1) and an ionic compound (A-2), and is characterized in that: the (meth) acrylic resin (A-1) contains structural units derived from an alkoxyalkyl (meth) acrylate in an amount of 10-40% by mass (inclusive) based on the total amount of structural units; the ionic compound (A-2) is an ionic compound containing an anionic moiety represented by formula (A-2-1) and an organic cation. (In the formula, R4 and R5 each independently represent a perfluoroalkyl group having 1-4 carbon atoms, or a perfluoroalkylene group having 1-8 carbon atoms formed by bonding R4 and R5. ] # imgabs0 #

Description

Technical Field

[0001] The present invention relates to an adhesive composition, an adhesive layer, and a polarizing plate with an adhesive. Background Art

[0002] Polarizing plates are widely used when installed in image display devices. As image display devices, liquid crystal display devices, organic EL display devices, etc. can be cited. Polarizing plates are circulated in a state where a transparent protective film is laminated on both sides or one side of the polarizer, a polarizing plate with an adhesive is formed on at least one surface, and a release film is attached to the adhesive layer. In addition, sometimes a phase element is laminated on a polarizing plate in a state where a protective film is attached to both sides or one side of the polarizer to make an elliptical polarizing plate, and an adhesive layer is formed on the side of the phase element. Before attaching to the image display device, the release film is peeled off from the adhesive layer on the surface of these polarizing plates, elliptical polarizing plates, and phase elements, and the image display device is attached with the exposed adhesive layer. Such polarizing plates, elliptical polarizing plates, or phase elements generate static electricity between the adhesive surface and the release film when peeling off the release film, and are attached to the image display device before the static electricity decays, which may cause an undesirable situation such as the image display device being destroyed due to static electricity.

[0003] As one of the countermeasures, Patent Document 1 below proposes using a composition comprising an ion conductive composition containing an electrolyte salt and an organopolysiloxane and an acrylic copolymer as an adhesive in a polarizing plate having a protective film laminated on the surface of a polarizer film and an adhesive layer provided on the surface of the protective film.

[0004] In addition, Patent Document 2 below discloses an antistatic acrylic adhesive comprising an acrylic copolymer having a hydroxyl group and an alkylene oxide chain such as an ethylene oxide chain in a side chain, an ionic compound, and a curing agent. Patent Document 2 uses an ionic compound having an inorganic cation such as a Li salt.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 6-313807

[0008] Patent Document 2: Japanese Patent Application Publication No. 2005-206776 Summary of the invention

[0009] Problems to be solved by the invention

[0010] In image display devices, metal wiring is used in display elements, touch panel elements, etc. When an ionic compound is added as a countermeasure to the static electricity, undesirable situations such as corrosion of the metal wiring by the ionic compound may occur. Among corrosion, pitting corrosion is particularly problematic because it penetrates the metal layer when the thickness of the metal layer is thin or when the metal layer is a metal wiring with a narrow line width.

[0011] When the adhesives disclosed in Patent Documents 1 and 2 are used, although antistatic properties are exhibited, the performance is not necessarily sufficient, and the metal corrosion prevention property is not necessarily sufficient.

[0012] Therefore, an object of the present invention is to provide an adhesive composition, an adhesive layer, and a polarizing plate with an adhesive having excellent adhesive strength, antistatic properties, and metal corrosion resistance.

[0013] Means for solving problems

[0014] In order to solve the above-mentioned problems, the present invention provides the following adhesive composition, adhesive layer, and adhesive-attached polarizing plate.

[0015] [1] An adhesive composition comprising a (meth)acrylic resin (A-1) and an ionic compound (A-2), wherein the (meth)acrylic resin (A-1) contains 10% by mass or more and 40% by mass or less of a structural unit derived from an alkoxyalkyl (meth)acrylate, based on the total amount of structural units constituting the (meth)acrylic resin (A-1), and the ionic compound (A-2) is an ionic compound comprising an anion portion represented by the following formula (A-2-1) and an organic cation.

[0016] [Chemical formula 1]

[0017]

[0018] [Where R 4 and R 5 Each independently represents a perfluoroalkyl group having 1 to 4 carbon atoms, or represents R 4 With R 5 A perfluoroalkylene group having 1 to 8 carbon atoms formed by bonding.]

[0019] [2] The pressure-sensitive adhesive composition according to [1], wherein the structural unit derived from the alkoxyalkyl (meth)acrylate includes a structural unit derived from a (meth)acrylate represented by the following formula (A-1-1).

[0020] [Chemical formula 2]

[0021]

[0022] [Where R 1 represents a hydrogen atom or a methyl group, R 2 represents an alkylene group having 1 to 4 carbon atoms, R 3 represents an alkyl group having 1 to 4 carbon atoms.]

[0023] [3] The adhesive composition according to [1] or [2], wherein the (meth)acrylic resin (A-1) contains 0.6% by mass or more and 10% by mass or less of a structural unit derived from a carboxyl group-containing monomer, based on the total amount of structural units constituting the (meth)acrylic resin (A-1).

[0024] [4] The adhesive composition according to any one of [1] to [3], wherein the (meth)acrylic resin (A-1) contains a structural unit derived from a (meth)acrylate represented by the following formula (A-1-2).

[0025] [Chemical formula 3]

[0026]

[0027] [Where R 6 represents a hydrogen atom or a methyl group, R 7 represents an alkyl group or an aralkyl group having 1 to 14 carbon atoms.]

[0028] [5] The adhesive composition according to [4], wherein the (meth)acrylic resin (A-1) contains 5% by mass or more and 50% by mass or less of the structural units constituting the (meth)acrylic resin (A-1) represented by the formula (A-1-2) and R 7 A structural unit of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms.

[0029] [6] The adhesive composition according to any one of [1] to [5], wherein the content of the ionic compound (A-2) is 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the (meth)acrylic resin (A-1).

[0030] [7] The adhesive composition according to any one of [1] to [6], wherein the melting point of the ionic compound (A-2) is 23° C. or higher.

[0031] [8] The adhesive composition according to any one of [1] to [7], wherein R of the anion portion of the ionic compound (A-2) 4 and R 5 All are trifluoromethyl.

[0032] [9] The adhesive composition according to any one of [1] to [8], wherein the organic cation of the ionic compound (A-2) contains a nitrogen atom.

[0033]

[10] A pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition according to any one of [1] to [9] above.

[0034]

[11] The pressure-sensitive adhesive layer according to

[10] above, wherein the thickness is 2 μm or more and 50 μm or less.

[0035]

[12] A polarizing plate with an adhesive, wherein a polarizing plate is bonded to the adhesive layer according to

[10] or

[11] .

[0036]

[13] The polarizing plate with an adhesive according to

[12] above, wherein the polarizing plate includes a phase element.

[0037] Effects of the Invention

[0038] According to the present invention, it is possible to provide an adhesive composition, an adhesive layer, and a polarizing plate with an adhesive having excellent adhesive strength, antistatic properties, and metal corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic cross-sectional view showing an example of the optical layered body of the present invention.

[0040] Figure 2 This is a schematic cross-sectional view showing another example of the optical layered body of the present invention.

[0041] Figure 3 This is a schematic cross-sectional view showing another example of the optical layered body of the present invention.

[0042] Description of Reference Numerals

[0043] 1 ... optical film with adhesive, 10 ... optical film, 20 ... adhesive layer, 30 ... metal layer, 40 ... substrate, 50 ... resin layer, 100, 200, 300 ... optical laminate. DETAILED DESCRIPTION

[0044] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[0045] <Adhesive composition>

[0046] The adhesive composition of the present invention contains a (meth)acrylic resin (A-1) and an ionic compound (A-2). The (meth)acrylic resin (A-1) contains 10% by mass or more and 40% by mass or less of a structural unit derived from an alkoxyalkyl (meth)acrylate, based on the total amount of structural units constituting the (meth)acrylic resin (A-1). The ionic compound (A-2) is an ionic compound containing an anion part represented by the following formula (A-2-1) and an organic cation.

[0047] [Chemical formula 4]

[0048]

[0049] In formula (A-2-1), R 4 and R 5 Each independently represents a perfluoroalkyl group having 1 to 4 carbon atoms, or represents R 4 With R 5 A perfluoroalkylene group having 1 to 8 carbon atoms formed by bonding.

[0050] According to the above-mentioned adhesive composition, by using the above-mentioned specific ionic compound (A-2), good antistatic property can be obtained, and, compared with the case of using other ionic compounds, metal corrosion resistance can be improved. In addition, according to the above-mentioned adhesive composition, by using the above-mentioned specific (meth) acrylic resin (A-1), metal corrosion resistance can be improved, and the ion conductivity of the adhesive composition is improved, and the antistatic effect brought by the ionic compound (A-2) can be improved. In addition, according to the above-mentioned adhesive composition, good adhesive force can be obtained.

[0051] [(Meth)acrylic resin (A-1)]

[0052] The (meth)acrylic resin (A-1) contains structural units derived from alkoxyalkyl (meth)acrylates. The structural units derived from alkoxyalkyl (meth)acrylates may, for example, contain structural units derived from (meth)acrylates represented by the following formula (A-1-1). The (meth)acrylic resin (A-1) may further contain at least one of structural units derived from (meth)acrylates represented by the following formula (A-1-2), structural units derived from carboxyl-containing monomers, and structural units derived from monomers having polar functional groups other than carboxyl groups. Here, (meth)acrylic acid refers to any of acrylic acid and methacrylic acid, and "(meth)" when referred to as (meth)acrylates, etc., has the same meaning.

[0053] [Chemical formula 5]

[0054]

[0055] In formula (A-1-1), R 1 represents a hydrogen atom or a methyl group, R 2 represents an alkylene group having 1 to 4 carbon atoms, R 3 It represents an alkyl group having 1 to 4 carbon atoms.

[0056] [Chemical formula 6]

[0057]

[0058] In formula (A-1-2), R 6 represents a hydrogen atom or a methyl group, R 7 It represents an alkyl group or an aralkyl group having 1 to 14 carbon atoms.

[0059] Among the (meth)acrylic acid alkoxyalkyl esters, as the (meth)acrylic acid ester represented by the above formula (A-1-1), specifically, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-methoxy-2-ethoxyethyl acrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-methoxy-2-ethoxyethyl methacrylate, etc. can be exemplified. These (meth)acrylic acid esters can be used alone or in combination with different (meth)acrylic acid esters. Among them, 2-methoxyethyl acrylate is preferably used as one of the (meth)acrylic acid esters constituting the (meth)acrylic resin (A-1).

[0060] In the (meth) acrylic resin (A-1), the content of the structural unit derived from the (meth) acrylic acid alkoxyalkyl ester is 10% by mass or more and 40% by mass or less, preferably 15% by mass or more and 40% by mass or less, more preferably 15% by mass or more and 35% by mass or less, and particularly preferably 20% by mass or more and 35% by mass or less, based on the total amount of the structural units constituting the (meth) acrylic resin (A-1). When the content is less than 10% by mass, the ionic conductivity of the adhesive is low, and therefore, in order to ensure the desired antistatic property, a large amount of antistatic agent needs to be added, and the metal corrosion resistance becomes low. If it exceeds 40% by mass, the polarity of the adhesive becomes high, thereby increasing the moisture content, which affects the adhesive properties.

[0061] The alkoxyalkyl (meth)acrylate may include a (meth)acrylate other than the (meth)acrylate represented by the above formula (A-1-1) (for example, R 2 is other than an alkylene group having 1 to 4 carbon atoms or R 3The structural units derived from the alkoxyalkyl (meth)acrylate may all be structural units derived from the (meth)acrylate represented by the above formula (A-1-1).

[0062] In the (meth)acrylate represented by the above formula (A-1-2), R 7 As the (meth)acrylate which is an alkyl group, specifically, there can be exemplified linear alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, and lauryl acrylate; branched alkyl acrylates such as isobutyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; linear alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, and lauryl methacrylate; and branched alkyl methacrylates such as isobutyl methacrylate, 2-ethylhexyl methacrylate, and isooctyl methacrylate. 7 Specific examples of the (meth)acrylate represented by formula (A-1-2) in the case of an aralkyl group include benzyl acrylate, benzyl methacrylate, etc. These (meth)acrylates may be used alone or in combination with different plural (meth)acrylates.

[0063] Among them, it is preferred to use R 7 When the (meth)acrylate represented by the formula (A-1-2) is an alkyl group having 1 to 3 carbon atoms, it is more preferable to use R 7 The (meth)acrylate represented by the formula (A-1-2) and R 7 (Meth)acrylic acid represented by formula (A-1-2) in the case of an alkyl group having 4 to 14 carbon atoms.

[0064] In the (meth)acrylic resin (A-1), the content of the structural unit derived from the (meth)acrylic ester represented by the above formula (A-1-2) is preferably 50% by mass or more and 89.4% by mass or less, more preferably 50% by mass or more and 84.4% by mass or less, further preferably 55% by mass or more and 84.4% by mass or less, and particularly preferably 55% by mass or more and 79.4% by mass or less, based on the total amount of the structural units constituting the (meth)acrylic resin (A-1). When the content is 50% by mass or more and 89.4% by mass or less, the adhesive force and durability can be appropriately adjusted.

[0065] In the (meth)acrylic resin (A-1), the 7The content of the structural unit of the (meth)acrylate represented by the formula (A-1-2) when it is an alkyl group having 1 to 3 carbon atoms is preferably 5% by mass or more and 50% by mass or less, based on the total amount of the structural units constituting the (meth)acrylic resin (A-1), more preferably 10% by mass or more and 40% by mass or less, further preferably 15% by mass or more and 35% by mass or less, and particularly preferably 20% by mass or more and 35% by mass or less. If the content is 5% by mass or more and 50% by mass or less, durability can be appropriately ensured.

[0066] In the (meth)acrylic resin (A-1), the 7 The content of the structural unit of the (meth)acrylate represented by the formula (A-1-2) when it is an alkyl group having 4 to 14 carbon atoms is preferably 0% by mass or more and 84.4% by mass or less, based on the total amount of the structural units constituting the (meth)acrylic resin (A-1), more preferably 10% by mass or more and 79.4% by mass or less, further preferably 15% by mass or more and 74.4% by mass or less, and particularly preferably 15% by mass or more and 69.4% by mass or less. If the content is 0% by mass or more and 84.4% by mass or less, the viscosity and durability of the adhesive can be appropriately adjusted.

[0067] (Meth) acrylic resin (A-1) preferably includes the structural unit from the monomer containing carboxyl. In (meth) acrylic resin (A-1), the content of the structural unit from the monomer containing carboxyl is preferably 0.6% by mass or more and 10% by mass or less based on the total amount of the structural units constituting the (meth) acrylic resin (A-1), more preferably 1% by mass or more and 5% by mass or less, and further preferably 1% by mass or more and 3% by mass or less. If the content is more than 0.6% by mass, the adhesion and durability are improved due to the improvement of the glass adhesion, and if it is less than 10% by mass, the excessive presence of the acid component can be suppressed, so the reduction of the anti-metal corrosion property can be suppressed, and in addition, the polarity of the adhesive can be suppressed to become higher, so the moisture content can be suppressed to become higher and affect the adhesive properties.

[0068] Examples of carboxyl-containing monomers include (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, (meth)acrylic acid carboxylalkyl esters (e.g., (meth)acrylic acid carboxylethyl ester, (meth)acrylic acid carboxylpentyl ester), etc. In addition, the carboxyl-containing monomer may be a monomer having a free carboxyl group such as β-carboxylethyl acrylate. Among them, (meth)acrylic acid is preferably used from the viewpoint of improving durability.

[0069] Examples of the monomer having a polar functional group other than a carboxyl group include monomers having a polar functional group such as a hydroxyl group, an amino group, and a heterocyclic group represented by an epoxy ring, and preferably a (meth)acrylic compound having a polar functional group.

[0070] Examples of monomers having polar functional groups include monomers having hydroxyl groups such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-chloro-2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, and 2-hydroxybutyl (meth)acrylate; monomers having heterocyclic groups such as acryloylmorpholine, vinyl caprolactam, N-vinyl-2-pyrrolidone, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, and 2,5-dihydrofuran; and monomers having amino groups different from heterocyclic groups such as N,N-dimethylaminoethyl (meth)acrylate. These monomers having polar functional groups may be used alone or in combination.

[0071] The polar functional group of the monomer having a polar functional group is preferably a hydroxyl group, an amino group or an epoxy ring. It is particularly preferred to use a monomer having a hydroxyl group as one of the monomers constituting the (meth)acrylic resin (A-1). In addition, in addition to the monomer having a hydroxyl group, it is also effective to use a monomer having other polar functional groups in combination.

[0072] In the (meth)acrylic resin (A-1), the content of the structural unit derived from the monomer having a polar functional group other than a carboxyl group is preferably 0.5% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 5% by mass or less, further preferably 0.5% by mass or more and 3% by mass or less, and particularly preferably 1.0% by mass or more and 3% by mass or less, based on the total amount of the structural units constituting the (meth)acrylic resin (A-1). If the content is 0.5% by mass or more, the number of reaction points with the crosslinking agent described later increases, and durability can be improved. If the content is 10% by mass or less, the polarity of the adhesive can be suppressed from becoming higher, and thus the moisture content can be suppressed from becoming higher and affecting the adhesive properties.

[0073] The (meth)acrylic resin (A-1) may contain structural units derived from other monomers other than the above-mentioned monomers. Examples of structural units derived from other monomers include structural units derived from (meth)acrylates having an alicyclic structure in the molecule, structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, and structural units derived from monomers having multiple (meth)acryloyl groups in the molecule.

[0074] The alicyclic structure refers to a cycloalkane structure having a carbon number of usually 5 or more, preferably about 5 to 7. Specific examples of acrylic acid esters having an alicyclic structure include isobornyl acrylate, cyclohexyl acrylate, dicyclopentyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, α-ethoxycyclohexyl acrylate, cyclohexylphenyl acrylate, and the like. Specific examples of methacrylic acid esters having an alicyclic structure include isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentyl methacrylate, cyclododecyl methacrylate, methylcyclohexyl methacrylate, trimethylcyclohexyl methacrylate, tert-butylcyclohexyl methacrylate, cyclohexylphenyl methacrylate, and the like.

[0075] Examples of styrene monomers include, in addition to styrene, alkyl styrenes such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, and octyl styrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; and nitrostyrene, acetyl styrene, methoxy styrene, and divinylbenzene.

[0076] Examples of vinyl monomers include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene halides such as vinylidene chloride; nitrogen-containing aromatic vinyl compounds such as vinyl pyridine, vinyl pyrrolidone, and vinyl carbazole; conjugated diene monomers such as butadiene, isoprene, and chloroprene; in addition, acrylonitrile, methacrylonitrile, and the like can also be mentioned.

[0077] Examples of monomers having multiple (meth)acryloyl groups in the molecule include monomers having two (meth)acryloyl groups in the molecule, such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate; and monomers having three (meth)acryloyl groups in the molecule, such as trimethylolpropane tri(meth)acrylate.

[0078] The above-mentioned other monomers may be used alone or in combination of two or more. In the (meth)acrylic resin (A-1), the content of the structural units derived from the other monomers may be 0% by mass or more and 20% by mass or less, or 0% by mass or more and 10% by mass or less, based on the total amount of the structural units constituting the (meth)acrylic resin (A-1).

[0079] The adhesive composition may contain one (meth) acrylic resin (A-1) alone, or may contain two or more. In addition, the adhesive composition may contain other (meth) acrylic resins that do not belong to the (meth) acrylic resin (A-1). When the adhesive composition contains other (meth) acrylic resins, the content of the (meth) acrylic resin (A-1) is preferably set to 60% by mass or more of the (meth) acrylic resin as a whole, and more preferably set to 80% by mass or more.

[0080] The weight average molecular weight (Mw) of the (meth) acrylic resin (A-1) based on standard polystyrene conversion of gel permeation chromatography (GPC) is preferably in the range of 1 million to 2 million. If the weight average molecular weight converted by standard polystyrene is more than 1 million, the adhesion under high temperature and high humidity is improved, and there is a tendency that the possibility of floating and peeling between the metal layer or glass substrate and the adhesive layer becomes lower, so it is preferred. In addition, if the weight average molecular weight is less than 2 million, the viscosity of the adhesive solution adjusted when making the adhesive layer becomes an appropriate range, which can suppress the stripes and unevenness during the production.

[0081] The glass transition temperature of the (meth)acrylic resin (A-1) is preferably in the range of -10 to -60°C, more preferably in the range of -20 to -50°C, and further preferably in the range of -30 to -45°C. The glass transition temperature of a resin can generally be measured using a differential scanning calorimeter.

[0082] The (meth)acrylic resin (A-1) may be composed of only the (meth)acrylic resin having a relatively high molecular weight as described above, or may be composed of a mixture of the (meth)acrylic resin (A-1) and a (meth)acrylic resin (A-1) having a different molecular weight. Examples of the (meth)acrylic resin (A-1) that can be used in a mixed manner include (meth)acrylic resins (A-1) having a weight average molecular weight in the range of 50,000 to 300,000.

[0083] The (meth)acrylic resin (A-1) (a mixture of the two when two or more are combined) is dissolved in ethyl acetate and adjusted to a non-volatile component concentration of 20% by mass. The solution preferably shows a viscosity of 20 Pa·s or less, more preferably 0.1 to 15 Pa·s at 25°C. If the viscosity at this time is 20 Pa·s or less, it is preferred because the generation of streaks when preparing the adhesive can be suppressed. The viscosity can be measured by a Brookfield viscometer.

[0084] The (meth)acrylic resin (A-1) can be produced by various known methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. In the production of the (meth)acrylic resin (A-1), a polymerization initiator is generally used. The polymerization initiator is used in an amount of about 0.001 to 5 parts by mass relative to a total of 100 parts by mass of all monomers used in the production of the (meth)acrylic resin (A-1).

[0085] As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, etc. are used. As the photopolymerization initiator, for example, 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, etc. are mentioned. Examples of the thermal polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis(2-methylpropionic acid)dimethyl ester, and 2,2'-azobis(2-hydroxymethylpropionitrile); organic peroxides such as lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl perbenzoate, isopropyl hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, and (3,5,5-trimethylhexanoyl)peroxide; and inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. Furthermore, a redox initiator using a peroxide and a reducing agent in combination can also be used as the polymerization initiator.

[0086] As a method for producing (meth)acrylic resin (A-1), among the above methods, solution polymerization is preferred. When a specific example of solution polymerization is cited for illustration, a method can be cited in which the desired monomer and organic solvent are mixed, a thermal polymerization initiator is added under a nitrogen atmosphere, and the mixture is stirred at about 40 to 90°C, preferably about 60 to 80°C for about 3 to 10 hours. In addition, in order to control the reaction, the monomer and thermal polymerization initiator can be added continuously or intermittently during the polymerization, or added in a state dissolved in an organic solvent. Here, as an organic solvent, for example, aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propanol and isopropanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone can be used.

[0087] [Ionic compound (A-2)]

[0088] The adhesive composition contains an ionic compound (A-2) as an antistatic agent in addition to the (meth)acrylic resin (A-1). The ionic compound (A-2) contains an anion part represented by the above formula (A-2-1) and an organic cation. The ionic compound (A-2) may be solid at room temperature (25°C).

[0089] Examples of the organic cation constituting the ionic compound (A-2) include imidazolium cations, pyridinium cations, pyrrolidinium cations, ammonium cations, sulfonium cations, and phosphonium cations. Among them, organic cations containing nitrogen atoms are preferred, and from the viewpoint of suppressing the change in the refractive index of the adhesive caused by the use of aromatic ring-containing compounds, aliphatic cations are more preferred, and pyrrolidinium cations and ammonium cations are further preferred.

[0090] Specific examples of organic cations include ammonium cations such as tributylmethylammonium cation, trioctylmethylammonium cation, trimethylpropylammonium cation, tetrabutylammonium cation, and (2-hydroxyethyl)trimethylammonium cation; phosphonium cations such as tributyldodecylphosphonium cation; pyridinium cations such as 1-hexylpyridinium cation, 1-octylpyridinium cation, 4-methyl-1-hexylpyridinium cation, 4-methyl-1-octylpyridinium cation, and 4-methyl-1-butylpyridinium cation; pyrrolidinium cations such as butylmethylpyrrolidinium cation and ethylmethylpyrrolidinium cation; imidazolium cations such as 1-ethyl-3-methylimidazolium cation and 1-butyl-3-methylimidazolium cation, and the like.

[0091] The anion constituting the ionic compound (A-2) is an anion represented by the above formula (A-2-1). Among them, from the viewpoint of the ease of developing antistatic performance at the same addition weight, it is preferred that R in the above formula (A-2-1) 4 and R 5 All are trifluoromethyl anions.

[0092] Specific examples of the anion represented by the above formula (A-2-1) include bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N - 〕、Bis(pentafluoroethanesulfonyl)imide anion〔(C2F5SO2)2N - 〕, bis(heptafluoropropanesulfonyl)imide anion, bis(nonafluorobutanesulfonyl)imide anion, trifluoromethanesulfonyl(pentafluoroethanesulfonyl)imide anion, trifluoromethanesulfonyl(heptafluoropropanesulfonyl)imide anion, trifluoromethanesulfonyl(nonafluorobutanesulfonyl)imide anion, 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide anion, etc.

[0093] The ionic compound (A-2) may be used alone or in combination of two or more. The pressure-sensitive adhesive composition may contain an ionic compound other than the above-mentioned ionic compound (A-2).

[0094] As described above, the ionic compound (A-2) imparts antistatic properties to the adhesive layer formed by the adhesive composition containing the (meth) acrylic resin (A-1), and is effective in maintaining various physical properties as an adhesive. In particular, when an ionic compound (A-2) that is solid at room temperature is used, the antistatic performance can be maintained for a long time compared to the case of using an ionic compound that is liquid at room temperature. From the viewpoint of long-term stability of antistatic properties, the ionic compound (A-2) preferably has a melting point of 23°C or more. On the other hand, if its melting point is too high, the compatibility with the (meth) acrylic resin (A-1) deteriorates, so it is preferably 90°C or less, more preferably 80°C or less, and particularly preferably 50°C or less. The molecular weight of the ionic compound (A-2) is not particularly limited, for example, the molecular weight is preferably 700 or less, and more preferably 500 or less.

[0095] The content of the ionic compound (A-2) in the adhesive composition is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, further preferably 0.1 to 2.5 parts by mass, and particularly preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the non-volatile components of the (meth) acrylic resin (A-1). If the ionic compound (A-2) is contained in an amount of 0.1 parts by mass or more relative to 100 parts by mass of the non-volatile components of the (meth) acrylic resin (A-1), the antistatic performance is improved, so it is preferred. In addition, if the amount is 10 parts by mass or less, it is possible to suppress the oozing out of the ionic compound from the adhesive layer during the durability test, and it is easy to maintain the durability, so it is preferred.

[0096] [Crosslinking agent]

[0097] The adhesive composition may further contain a crosslinking agent. The crosslinking agent is a compound having at least two functional groups in the molecule that can crosslink with structural units derived from, for example, a monomer having a polar functional group in the (meth)acrylic resin (A-1), and specifically, isocyanate compounds, epoxy compounds, metal chelate compounds, aziridine compounds, etc. can be exemplified.

[0098] Isocyanate compounds are compounds having at least two isocyanate groups (-NCO) in the molecule, and examples thereof include toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc. In addition, adducts obtained by reacting polyols such as glycerol and trimethylolpropane with these isocyanate compounds, and substances obtained by making isocyanate compounds into dimers, trimers, etc. can also be crosslinking agents used in adhesives. Two or more isocyanate compounds can also be used in combination.

[0099] The epoxy compound is a compound having at least two epoxy groups in the molecule, and examples thereof include bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N-diglycidyl aniline, N,N,N',N'-tetraglycidyl-m-xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, etc. Two or more epoxy compounds may be used in combination.

[0100] Examples of the metal chelate compound include compounds in which acetylacetone or ethyl acetoacetate is coordinated to a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium.

[0101] The aziridine compound is a compound having at least two three-membered ring skeletons containing one nitrogen atom and two carbon atoms, also called ethyleneimines, in the molecule, and examples thereof include diphenylmethane-4,4'-bis(1-aziridinecarboxamide), toluene-2,4-bis(1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1-(2-methylaziridine), tri-1-aziridinylphosphine oxide, hexamethylene-1,6-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolmethane-tri-β-aziridinyl propionate, and the like.

[0102] Among these crosslinking agents, it is preferred to use isocyanate compounds, especially xylylene diisocyanate, toluene diisocyanate or hexamethylene diisocyanate, or adducts formed by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, materials formed by making isocyanate compounds into dimers, trimers, etc., mixtures of these isocyanate compounds, etc. In the case where the monomer containing polar functional groups has a polar functional group selected from free carboxyl, hydroxyl, amino and epoxy ring, it is particularly preferred to use at least one isocyanate compound as a crosslinking agent. As suitable isocyanate compounds, toluene diisocyanate, adducts obtained by reacting toluene diisocyanate with polyols, dimers of toluene diisocyanate, and trimers of toluene diisocyanate, and hexamethylene diisocyanate, adducts obtained by reacting hexamethylene diisocyanate with polyols, dimers of hexamethylene diisocyanate, and trimers of hexamethylene diisocyanate can be cited.

[0103] The crosslinking agent is added in a ratio of 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and particularly preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the nonvolatile components of the (meth) acrylic resin (A-1). If the amount of the crosslinking agent is 0.01 parts by mass or more relative to 100 parts by mass of the nonvolatile components of the (meth) acrylic resin (A-1), the fluidity of the adhesive can be prevented from becoming too high, thereby preventing the deformation amount during the durability test from becoming large. In addition, if it is 10 parts by mass or less, the adhesive can be prevented from becoming too hard, thereby easily preventing the occurrence of undesirable conditions such as the breakage of the adhesive during the durability test.

[0104] [Other components constituting the adhesive composition]

[0105] In order to improve the adhesion between the adhesive layer and the metal layer or the glass substrate, the adhesive composition used to form the adhesive layer in the present invention preferably contains a silane compound, and it is particularly preferred that the silane compound is preliminarily contained in the acrylic resin before the crosslinking agent is added.

[0106] Examples of the silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, and 3-glycidoxypropylethoxydimethylsilane. Two or more silane compounds may be used.

[0107] The silane compound may be a silicone oligomer type silane compound. If the silicone oligomer is represented in the form of a copolymer, for example, the following substances may be mentioned. That is, 3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer and other copolymers containing mercaptopropyl group; mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, mercaptomethyltriethoxysilane-tetraethoxysilane copolymer and other copolymers containing mercaptomethyl group may be mentioned; 3-methacryloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer and other copolymers containing mercaptomethyl group may be mentioned. Methoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropyl trimethoxysilane-tetraethoxysilane copolymer, 3-methacryloxypropyl triethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropyl triethoxysilane-tetraethoxysilane copolymer, 3-methacryloxypropyl methyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropyl methyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloxypropyl methyldiethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropyl methyldiethoxysilane-tetraethoxy Silane copolymers and other copolymers containing methacryloxypropyl; 3-acryloxypropyl trimethoxysilane-tetramethoxysilane copolymer, 3-acryloxypropyl trimethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropyl triethoxysilane-tetramethoxysilane copolymer, 3-acryloxypropyl triethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropyl methyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloxypropyl methyldimethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropyl methyldiethoxysilane-tetramethoxysilane copolymer, 3-acryloxypropyl Copolymers containing acryloxypropyl groups, such as acyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymers; copolymers containing vinyl groups, such as vinyltrimethoxysilane-tetramethoxysilane copolymers, vinyltrimethoxysilane-tetraethoxysilane copolymers, vinyltriethoxysilane-tetramethoxysilane copolymers, vinyltriethoxysilane-tetraethoxysilane copolymers, vinylmethyldimethoxysilane-tetramethoxysilane copolymers, vinylmethyldimethoxysilane-tetraethoxysilane copolymers, vinylmethyldiethoxysilane-tetramethoxysilane copolymers, and vinylmethyldiethoxysilane-tetraethoxysilane copolymers;3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer and the like amino group-containing copolymers, etc.;

[0108] From the viewpoint of metal surface coverage, the molecular weight of these silane compounds is preferably 1000 or less, more preferably 500 or less, and particularly preferably 250 or less. From the viewpoint of bonding between the silane compound and the adhesive composition, the silane compound preferably contains an epoxy group.

[0109] These silane compounds are liquid in most cases. The amount of the silane compound in the adhesive composition is usually about 0.01 to 10 parts by mass relative to 100 parts by mass of the non-volatile component of the (meth) acrylic resin (A-1) (the total mass when two or more are used), preferably used in a ratio of 0.03 to 5 parts by mass, and more preferably used in a ratio of 0.1 to 1 part by mass. If the amount of the silane compound is 0.01 parts by mass or more relative to 100 parts by mass of the non-volatile component of the (meth) acrylic resin (A-1), the adhesion between the adhesive layer and the metal layer or the glass substrate is improved, so it is preferred. In addition, if the amount is less than 10 parts by mass, there is a tendency to suppress the oozing of the silane compound from the adhesive layer, so it is preferred.

[0110] In the adhesive composition described above, it is possible to further coordinate crosslinking catalyst, weathering stabilizer, tackifier, plasticizer, softener, dye, pigment, inorganic filler, resin other than (methyl) acrylic resin (A-1) etc. In addition, it is also useful to coordinate ultraviolet curable compound in adhesive composition, irradiate ultraviolet rays to solidify it after forming adhesive layer, and make harder adhesive layer. Wherein, if coordinate crosslinking catalyst together with crosslinking agent in adhesive composition, adhesive layer can be prepared with short-time ripening, in the resin film with adhesive obtained, it is possible to suppress floating, peeling or foaming in adhesive layer between resin film and adhesive layer. As crosslinking catalyst, for example, amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resin, melamine resin etc. can be cited. In the case of coordinating amine compound as crosslinking catalyst in adhesive composition, as crosslinking agent, isocyanate compound is suitable.

[0111] The components constituting the adhesive composition are applied onto an appropriate substrate in a state of being dissolved in a solvent and dried to form an adhesive layer.

[0112] <Optical film with adhesive>

[0113] The optical film with adhesive of the present invention is provided with an adhesive layer formed by the above adhesive composition on at least one side of the optical film. The optical film used herein refers to a film with optical properties, for example, a polarizing plate (linear polarizing plate, circular polarizing plate) etc. can be cited. The polarizing plate can include a phase difference film. That is, the optical film with adhesive can be a polarizing plate with adhesive.

[0114] (Optical Film)

[0115] As the optical film, there can be cited a linear polarizing layer; a linear polarizing plate having a protective layer on one or both sides of the linear polarizing layer; a circular polarizing plate comprising a linear polarizing layer or a linear polarizing plate and one or more phase elements; a polarizing plate with a surface protective film having a surface protective film on one side of a polarizing plate such as a linear polarizing plate and a circular polarizing plate; a phase element; a phase difference plate having a protective layer on one or both sides of a phase element; a reflective film; a semi-transmissive reflective film; a brightness enhancement film; a film with an anti-glare function, etc., and one of them or a combination of two or more thereof can be used. The optical film preferably comprises at least a linear polarizing layer, and more preferably comprises a linear polarizing plate or a circular polarizing plate. The phase element contained in the circular polarizing plate comprises at least one phase difference film, and at least one is usually a λ / 4 phase difference film.

[0116] (Linear polarization layer)

[0117] The linear polarizing layer has the property of transmitting linear polarized light having a vibration plane orthogonal to the absorption axis when non-polarized light is incident. The linear polarizing layer may be a polyvinyl alcohol-based resin film (hereinafter sometimes referred to as a "PVA-based film") in which iodine is adsorbed and oriented, or a film comprising a liquid crystal polarizing layer formed by applying a composition containing a compound having absorption anisotropy and liquid crystal properties to a substrate film. The compound having absorption anisotropy and liquid crystal properties may be a mixture of a pigment having absorption anisotropy and a compound having liquid crystal properties, or may be a pigment having absorption anisotropy and liquid crystal properties.

[0118] As the linear polarizing layer of the PVA film, for example, there can be mentioned a linear polarizing layer obtained by dyeing and stretching a PVA film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or a partially saponified film of an ethylene-vinyl acetate copolymer. If necessary, the PVA film that has been oriented by iodine adsorption by dyeing can be treated with an aqueous boric acid solution, and then a washing step of washing away the aqueous boric acid solution can be performed. Each step can be performed by a known method.

[0119] Polyvinyl alcohol resin (hereinafter, sometimes referred to as "PVA resin") can be produced by saponifying polyvinyl acetate resin. Polyvinyl acetate resin may be a copolymer of vinyl acetate and other monomers copolymerizable with vinyl acetate, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

[0120] The saponification degree of PVA resin is usually about 85 to 100 mol%, preferably 98 mol% or more. PVA resin can be modified, for example, polyvinyl formal, polyvinyl acetal, etc. modified by aldehydes can also be used. The average polymerization degree of PVA resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000. The saponification degree and average polymerization degree of PVA resin can be calculated according to JIS K 6726 (1994). If the average polymerization degree is less than 1000, it is difficult to obtain the preferred polarization performance. If it exceeds 10000, the film processability is sometimes poor.

[0121] The method for manufacturing a linear polarizing layer as a PVA film may include preparing a substrate film, applying a solution of a resin such as a PVA resin on the substrate film, removing the solvent and drying, etc. to form a resin layer on the substrate film. It should be noted that a primer layer may be formed in advance on the surface of the substrate film on which the resin layer is to be formed. As the substrate film, a film using a resin material described as a thermoplastic resin for forming a protective film as a protective layer described later can be used. As the material of the primer layer, a resin obtained by cross-linking a hydrophilic resin used for the linear polarizing layer can be cited.

[0122] Next, the amount of solvent such as water in the resin layer is adjusted as needed, and then the base film and the resin layer are uniaxially stretched, and then the resin layer is dyed with iodine so that the iodine is adsorbed and oriented in the resin layer. Next, the resin layer adsorbed and oriented with iodine is treated with an aqueous boric acid solution as needed, and then a washing step of washing away the aqueous boric acid solution is performed. Thus, a PVA film having a resin layer adsorbed and oriented with iodine, i.e., a linear polarizing layer, is manufactured. Each step can adopt a known method.

[0123] The amount of boric acid in the boric acid-containing aqueous solution for treating the PVA film or resin layer in which iodine is adsorbed and oriented is generally about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, relative to 100 parts by mass of water. The boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is generally about 0.1 to 15 parts by mass, preferably about 5 to 12 parts by mass, relative to 100 parts by mass of water. The immersion time in the boric acid-containing aqueous solution is generally about 60 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is generally above 50°C, preferably 50 to 85°C, and more preferably 60 to 80°C.

[0124] The uniaxial stretching of the PVA film, the substrate film and the resin layer can be performed before dyeing, during dyeing, during the boric acid treatment after dyeing, or separately in these multiple stages. The PVA film, the substrate film and the resin layer can be uniaxially stretched along the MD direction (film conveying direction). In this case, the uniaxial stretching can be performed between rollers with different peripheral speeds, or a hot roller can be used for uniaxial stretching. In addition, the PVA film, the substrate film and the resin layer can be uniaxially stretched along the TD direction (a direction perpendicular to the film conveying direction). In this case, the so-called tenter method can be used. In addition, the above-mentioned stretching can be a dry stretching performed in the atmosphere, or a wet stretching performed in a state where the PVA film or the resin layer is swollen using a solvent. In order to show the performance of the linear polarization layer, the stretching ratio is 4 times or more, preferably 5 times or more, and particularly preferably 5.5 times or more. The upper limit of the stretching ratio is not particularly limited, and from the viewpoint of suppressing breakage, etc., it is preferably 8 times or less.

[0125] The linear polarizing layer produced by the manufacturing method using the base film can be obtained by laminating the protective layer and then peeling off the base film. According to this method, the linear polarizing layer can be further reduced in thickness.

[0126] The thickness of the linear polarizing layer as the PVA film is preferably 1 μm or more, 2 μm or more, or 5 μm or more, and preferably 30 μm or less, more preferably 15 μm or less, 10 μm or less, or 8 μm or less. If the thickness of the linear polarizing layer is less than 1 μm, there is a possibility of undesirable conditions such as breakage during the process, and if it exceeds 30 μm, the optical film becomes thick, which is not appropriate.

[0127] The film containing a liquid crystal linear polarizing layer may include a linear polarizing layer obtained by coating a composition containing a pigment having liquid crystal and absorption anisotropy, or a composition containing a pigment having absorption anisotropy and a polymerizable liquid crystal on a substrate film. The liquid crystal linear polarizing layer may be a cured product of a polymerizable liquid crystal compound, and may include an oriented film. As an oriented film, an oriented film contained in a phase difference film described later may be cited. The film containing a liquid crystal linear polarizing layer may be a liquid crystal linear polarizing layer, or may have a laminated structure of a liquid crystal linear polarizing layer and a substrate film. As a substrate film, for example, a film using a resin material described as a thermoplastic resin for forming a protective film as a protective layer described later may be cited. As a film containing a liquid crystal linear polarizing layer, for example, a polarizing layer described in Japanese Patent Gazette No. 2013-33249 may be cited.

[0128] The combined thickness of the substrate film and the linear polarizing layer formed as described above is preferably as small as possible, but if it is too small, the strength tends to decrease and the processability tends to be poor, so it is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 to 3 μm.

[0129] (Protective layer)

[0130] As the protective layer, for example, there can be mentioned a protective film which is a film formed of a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, stretchability, etc.; an overcoat layer formed of a composition having excellent solvent resistance, transparency, mechanical strength, thermal stability, barrier property, isotropy, etc. The protective film is preferably laminated on the linear polarizing layer via a laminating layer, and the overcoat layer is preferably laminated in direct contact with the linear polarizing layer.

[0131] Specific examples of thermoplastic resins for forming the protective film include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resins; polysulfone resins; polycarbonate resins; polyamide resins such as nylon and aromatic polyamide; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin resins having a ring system and a norbornene structure (also referred to as norbornene resins); (meth) acrylic resins; polyarylate resins; polystyrene resins; polyvinyl alcohol resins, and mixtures thereof. The thickness of the protective film is preferably 3 μm or more, more preferably 5 μm or more, and preferably 50 μm or less, more preferably 30 μm or less.

[0132] The outer coating layer can be formed of a composition having excellent solubility, transparency, mechanical strength, thermal stability, barrier properties, and isotropy. The outer coating layer can be formed, for example, by coating the above composition on the linear polarizing layer. As materials constituting the outer coating layer, for example, photocurable resins, water-soluble polymers, etc. can be cited, and (meth) acrylic resins, polyvinyl alcohol resins, polyamide epoxy resins, etc. can be used. The thickness of the outer coating layer can be, for example, 0.1 μm or more and 10 μm or less.

[0133] The protective layer may have anti-reflection properties, anti-glare properties, hard coating properties, etc. (hereinafter, the protective film having such properties is sometimes referred to as a "functional protective layer".). In the case where the protective layer is not a functional protective layer, a surface functional layer such as an anti-reflection layer, an anti-glare layer, a hard coating layer, etc. may be provided on one side of the linear polarizing plate. The surface functional layer is preferably provided in direct contact with the protective layer. The surface functional layer is preferably provided on the side of the protective layer opposite to the linear polarizing layer side.

[0134] In the above, the case where the protective layer is provided on the linear polarization layer is described, but the protective layer may be provided on the retardation film.

[0135] (Phase Element)

[0136] The phase element is an optical element that shows a phase difference in the plane or in the thickness direction, and includes at least one phase difference film. The phase difference film can be one, or two or more phase difference films can be bonded together using a known adhesive or adhesive. Among them, when two phase difference films are used in combination, the phase difference can be appropriately adjusted when used as a circular polarizing plate, so it is preferred.

[0137] (Phase difference film)

[0138] The retardation film is a film showing a retardation in a plane or in a thickness direction, and may be a stretched film or a film including a cured layer of a polymerizable liquid crystal compound.

[0139] When the phase difference film is a stretched film, the stretched film can use a conventionally known stretched film, and a stretched film imparted with a phase difference by uniaxially stretching or biaxially stretching the resin film can be used. As the resin film, cellulose films such as triacetyl cellulose and diacetyl cellulose, polyester films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate, acrylic resin films such as poly(methyl)acrylate and poly(ethyl)acrylate, polycarbonate films, polyether sulfone films, polysulfone films, polyimide films, polyolefin films, polynorbornene films, etc. can be used, but are not limited to these.

[0140] When the phase difference film includes the cured product layer, a known polymerizable liquid crystal compound can be used as the polymerizable liquid crystal compound. The polymerizable liquid crystal compound is a compound having at least one polymerizable group and having liquid crystallinity.

[0141] The polymerizable group possessed by the polymerizable liquid crystal compound refers to a group participating in the polymerization reaction, preferably a photopolymerizable group. The photopolymerizable group refers to a group that can participate in the polymerization reaction by an active free radical, acid, etc. generated by a photopolymerization initiator. As a polymerizable group, vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, (meth) acryloyloxy, oxiranyl, oxetane, styryl, allyl, etc. can be cited. Among them, (meth) acryloyloxy, vinyloxy, oxiranyl and oxetane are preferred, and acryloyloxy is more preferred. The liquid crystal properties possessed by the polymerizable liquid crystal compound can be thermotropic liquid crystals or lyotropic liquid crystals. If thermotropic liquid crystals are classified by order, they can be nematic liquid crystals or smectic liquid crystals. In the case of using two or more polymerizable liquid crystal compounds in combination to form a cured layer of a polymerizable liquid crystal compound, it is preferred that at least one has two or more polymerizable groups in the molecule.

[0142] In the case where the phase difference film includes the above-mentioned cured product layer, the phase difference film may include an orientation film. The orientation film has an orientation restriction force that orients the polymerizable liquid crystal compound in the desired direction. The orientation film may be a vertical orientation film that orients the molecular axis of the polymerizable liquid crystal compound vertically relative to the plane direction of the laminate, or a horizontal orientation film that orients the molecular axis of the polymerizable liquid crystal compound horizontally relative to the plane direction of the laminate, or an inclined orientation film that orients the molecular axis of the polymerizable liquid crystal compound obliquely relative to the plane direction of the laminate.

[0143] About the above-mentioned solidified material layer, the composition for the phase difference film formation containing polymerizable liquid crystal compound and solvent, various additives as needed is applied to the alignment film to form a coating film, and the coating film is solidified (hardened), thereby forming a solidified material layer of the polymerizable liquid crystal compound. Alternatively, the above-mentioned composition can also be applied to the substrate film to form a coating film, and the coating film is stretched together with the substrate film to form a solidified material layer. The above-mentioned composition, in addition to the above-mentioned polymerizable liquid crystal compound and solvent, may include a polymerization initiator, a reactive additive, a leveling agent, an inhibitor, etc. Polymerizable liquid crystal compound, solvent, polymerization initiator, reactive additive, leveling agent, inhibitor, etc. can be appropriately used with known substances. As a substrate film, a film of a resin material described as a thermoplastic resin for forming a protective film as the above-mentioned protective layer can be used.

[0144] (Surface protection film)

[0145] The surface protection film is provided so as to be releasable from the polarizing plate. The surface protection film may have a single-layer structure or a multi-layer structure. The surface protection film may include a substrate layer and a second adhesive layer, or may be a self-adhesive substrate layer.

[0146] As the substrate layer constituting the surface protection film, a film using the resin material described as a thermoplastic resin for forming a protective film as the above-mentioned protective layer can be used. As the adhesive composition for forming the second adhesive layer, a known adhesive composition can be used to form it. As a known adhesive composition, the adhesive composition described in the above-mentioned adhesive composition can be cited.

[0147] The surface protective film comprising the substrate layer and the second adhesive layer can be formed by applying the adhesive composition itself or an organic solvent dilution of the adhesive composition on the substrate layer and drying. As a method for applying the adhesive composition or its organic solvent dilution, for example, a rod coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, etc. can be cited.

[0148] When the surface protection film has self-adhesiveness, examples of the thermoplastic resin constituting the self-adhesive base layer include polypropylene-based resins and polyethylene-based resins.

[0149] In the above, the case where the surface protection film is used for the polarizing plate is described. However, the surface protection film may be laminated on a member exemplified as the optical film other than the polarizing plate.

[0150] (Lamination layer)

[0151] When the optical film has a multilayer structure, the interlayers can be bonded by a bonding layer. The bonding layer is an adhesive layer or an adhesive layer. When the bonding layer is an adhesive layer, it can be formed using a known adhesive composition. As a known adhesive composition, the adhesive composition described in the above-mentioned adhesive composition can be cited.

[0152] When the laminating layer is an adhesive layer, the adhesive layer can be formed by curing the curable component in the adhesive composition. As the adhesive composition for forming the adhesive layer, adhesives other than pressure-sensitive adhesives (adhesives) can be cited, such as water-based adhesives and active energy ray-curable adhesives.

[0153] Examples of the water-based adhesive include an adhesive obtained by dissolving or dispersing a polyvinyl alcohol resin in water. The drying method when using the water-based adhesive is not particularly limited, and for example, a method of drying using a hot air dryer or an infrared dryer may be used.

[0154] Examples of active energy ray-curable adhesives include solvent-free active energy ray-curable adhesives containing curable compounds that are cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. By using solvent-free active energy ray-curable adhesives, interlayer adhesion can be improved.

[0155] (Optical film with adhesive)

[0156] The optical film with adhesive preferably has a release film attached to the surface of its adhesive layer to protect the surface of the adhesive layer until use. The optical film with adhesive provided with a release film can be manufactured by, for example, the following methods: a method of coating the above-mentioned adhesive composition on a release film to form an adhesive layer, and further laminating an optical film on the obtained adhesive layer; a method of coating an adhesive composition on an optical film to form an adhesive layer, and laminating a release film on its adhesive surface for protection; a method of coating the above-mentioned adhesive composition on a release film to form an adhesive layer, further laminating another release film on the obtained adhesive layer, peeling off one release film, laminating an optical film on the exposed adhesive surface to form an optical film with adhesive, etc. From the viewpoint of stabilizing the physical properties of the adhesive during the curing period, the following method is particularly preferred: a method of coating the above-mentioned adhesive composition on a release film to form an adhesive layer, further laminating another release film on the obtained adhesive layer, peeling off one release film, laminating an optical film on the exposed adhesive surface, and making an optical film with adhesive provided with a release film. In particular, the release film used here may be, for example, a release film having a film containing various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate as a base material, and a release film having the bonding surface of the base material with the adhesive layer subjected to a release treatment such as silicone treatment.

[0157] The thickness of the adhesive layer is not particularly limited, and is generally preferably 2 μm or more and 50 μm or less, more preferably 5 μm or more and 30 μm or less, further preferably 5 μm or more and 25 μm or less, and particularly preferably 10 μm or more and 20 μm or less. If the thickness of the adhesive layer is 2 μm or more, it is possible to suppress the decrease in adhesion, thereby reducing the possibility of poor durability. If it is 50 μm or less, when the adhesive or the optical film with the adhesive is cut, it is possible to suppress the occurrence of poor conditions such as the end face of the adhesive adhering to the cutting blade and falling off.

[0158] The optical film with a pressure-sensitive adhesive of the present invention can be suitably used in image display devices and the like because the pressure-sensitive adhesive layer has excellent adhesive strength, antistatic properties, and metal corrosion resistance.

[0159] <Optical laminate>

[0160] Figure 1 Schematic cross-sectional view showing an example of the optical laminate of the present invention. Figure 1 As shown, the optical laminate 100 of the present invention includes an optical film 10, an adhesive layer 20 and a metal layer 30 in sequence, and may further include a substrate 40. The optical laminate 100 may be an optical laminate formed by laminating an optical film 1 with an adhesive, which includes an optical film 10 and an adhesive layer 20 laminated on at least one surface thereof, on a metal layer 30 formed on a substrate 40 via the adhesive layer 20. As the optical film 1 with an adhesive, the optical film described above may be used. The optical film 10 may be an optical film of a single-layer structure or an optical film of a multi-layer structure.

[0161] The adhesive layer 20 is usually directly laminated on the surface of the optical film 10. In addition, usually, the optical film 1 with an adhesive is laminated on the metal layer 30 in a manner that the adhesive layer 20 is in direct contact with the metal layer 30. In addition, as described later, in the case where the metal layer 30 has a resin layer 50, the adhesive layer 20 is laminated in a manner that the resin layer 50 is in direct contact with the resin layer 50. According to the present invention, since the adhesive layer 20 is formed using the above-mentioned adhesive composition of the present invention, the corrosion of the metal layer 30 can be effectively suppressed in the optical laminate 100. In addition, the adhesive layer 20 has good adhesion to the optical film 10, the metal layer 30 and the substrate 40, and has good antistatic properties. In this specification, the property that can suppress the corrosion of the metal layer 30 is also referred to as metal corrosion resistance.

[0162] The metal layer 30 may be, for example, a layer containing one or more metals selected from aluminum, titanium, copper, silver, gold, iron, tin, zinc, nickel, molybdenum, chromium, tungsten, lead, and alloys containing two or more metals selected from these. From the viewpoint of conductivity, it is preferably a layer containing a metal element selected from aluminum, titanium, copper, silver, and gold. From the viewpoint of conductivity and cost, it is more preferably a layer containing aluminum, and further preferably a layer containing aluminum as a main component. Containing as a main component means that the metal component constituting the metal layer 30 is 30% by mass or more of all metal components, and further 50% by mass or more.

[0163] The metal layer 30 may be, for example, a metal oxide layer such as ITO, but from the perspective that the optical film 1 with an adhesive of the present invention has good corrosion resistance to metal monomers and alloys, the metal layer 30 preferably includes a metal monomer formed of the above-mentioned metal elements and / or an alloy containing two or more of the above-mentioned metal elements. However, the optical laminate 100 may also have a transparent electrode layer containing a metal oxide such as ITO together with such a metal layer 30.

[0164] The morphology (such as thickness, etc.) and preparation method of the metal layer 30 are not particularly limited. In addition to being a metal foil, it can also be formed by vacuum evaporation, sputtering, ion plating, inkjet printing, and gravure printing. It is preferably a metal layer formed by sputtering, inkjet printing, and gravure printing, and more preferably a metal layer formed by sputtering. For metal layers and metal foils formed by sputtering, the former has a tendency to have poor corrosion resistance, but according to the optical laminate 100, the metal layer formed by sputtering also has good metal corrosion resistance. The thickness of the metal layer 30 is generally less than 3 μm, preferably less than 1 μm, and more preferably less than 0.8 μm. In addition, the thickness of the metal layer 30 is generally more than 0.01 μm. In addition, when the metal layer 30 is a metal wiring layer, the line width of the metal wiring possessed by the metal wiring layer is generally less than 10 μm, preferably less than 5 μm, and more preferably less than 3 μm. In addition, the line width of the metal wiring is usually 0.01 μm or more, preferably 0.1 μm or more, and more preferably 0.5 μm or more. The optical laminate 100 also shows good metal corrosion resistance for the metal layer 30 of the thin film and the metal layer 30 of the metal wiring including fine wires. In particular, even in the case where the metal wiring has a thickness of 3 μm or less and a line width of 10 μm or less, or a thickness of 3 μm or less and a line width of 10 μm or less and is formed by sputtering, its corrosion, especially pitting corrosion, can be suppressed.

[0165] The metal layer 30 may be, for example, a metal wiring layer (i.e., an electrode layer) of a touch input element of a touch input type image display device, or a display element of an organic EL panel. In this case, the metal layer 30 is usually patterned into a predetermined shape. When the adhesive layer 20 is stacked on the patterned metal layer 30, the adhesive layer 20 may have a portion that is not in contact with the metal layer 30. The metal layer 30 may be a continuous film containing the above-mentioned metal or alloy.

[0166] The metal layer 30 may be a single layer structure or a multilayer structure of two or three layers or more. Examples of the multilayer metal layer include a metal-containing layer (metal mesh, etc.) having a three-layer structure represented by molybdenum / aluminum / molybdenum.

[0167] like Figure 1 As shown, for example, a metal layer 30 as a metal wiring layer is usually formed on a substrate 40, and in this case, the optical laminate 100 includes the substrate 40. The metal layer 30 can be formed on the substrate 40 by, for example, sputtering. The substrate 40 can be a transparent substrate constituting an image display device included in a touch input element, or a display element of an organic EL panel. The metal layer 30 can be formed on the entire surface of the substrate 40, or can be formed on a portion thereof.

[0168] Figure 2Schematic cross-sectional view showing another example of the layer structure of the optical layered body of the present invention. In another embodiment, the optical layered body of the present invention is as follows Figure 2 As shown in the optical laminate 200, the adhesive layer 20 of the optical film 1 with adhesive is laminated on the metal layer 30 via the resin layer 50. The adhesive layer 20 is in direct contact with the resin layer 50. In this optical laminate 200, the corrosion of the metal layer 30 can also be effectively suppressed. The resin layer 50 disposed between the adhesive layer 20 and the metal layer 30 can be, for example, a cured layer of a curable resin. As the curable resin capable of forming the resin layer 50, a known curable resin can be used.

[0169] As described above, the metal layer 30 may be a metal wiring layer. An example of a case where the metal layer 30 is a metal wiring layer is shown in FIG. Figure 3 .exist Figure 3 In the optical laminate 300 shown, the resin layer 50 may be omitted.

[0170] The optical laminate can be produced, for example, by laminating the optical film 1 with a pressure-sensitive adhesive, which includes the optical film 10 and the pressure-sensitive adhesive layer 20 laminated on at least one surface thereof, onto the metal layer 30 formed on the substrate 40 via the pressure-sensitive adhesive layer 20 .

[0171] As described above, the optical film 1 with adhesive comprises an optical film 10 and an adhesive layer 20 ( Figure 1 ). The adhesive layer 20 may be laminated on both sides of the optical film 10. Usually, the adhesive layer 20 is directly laminated on the surface of the optical film 10. When the adhesive layer 20 is provided on the surface of the optical film 10, it is preferred to form a primer layer on the bonding surface of the optical film 10 and / or the bonding surface of the adhesive layer 20, and to perform surface activation treatment, such as plasma treatment, corona treatment, etc., and more preferably perform corona treatment.

[0172] An antistatic layer can be separately provided between the optical film 10 and the adhesive layer 20, but the adhesive layer 20 of the present invention can impart excellent antistatic properties as the adhesive layer alone. Therefore, from the perspective of thin filmization of the optical laminate and simplification of the laminate production process, it is preferred that there is no antistatic layer between the optical film 10 and the adhesive layer 20.

[0173] The optical film 1 with an adhesive may include a separator (release film) laminated on the outer surface of the adhesive layer 20. The separator is usually peeled off and removed when the adhesive layer 20 is used (for example, when laminated on the metal layer 30). For example, the separator may be a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate, on which the adhesive layer 20 is formed, subjected to a release treatment such as silicone treatment.

[0174] The optical film 1 with adhesive can be obtained by dissolving or dispersing the components constituting the above-mentioned adhesive composition in a solvent to prepare a solvent-containing adhesive composition, and then applying the solvent composition to the surface of the optical film 10 and drying it to form the adhesive layer 20. In addition, the optical film 1 with adhesive can also be obtained by forming the adhesive layer 20 on the release-treated surface of the diaphragm in the same manner as above, and laminating (transferring) the adhesive layer 20 on the surface of the optical film 10.

[0175] An optical laminate can be obtained by bonding an optical film 1 with an adhesive to a metal layer 30 (or the above-mentioned resin layer) via its adhesive layer 20. After bonding the optical film 1 with an adhesive to the metal layer 30 to produce an optical laminate, in the case of some undesirable conditions, it is sometimes necessary to perform a so-called reprocessing operation of peeling the optical film 1 with an adhesive from the metal layer 30 and re-bonding another optical film 1 with an adhesive to the metal layer 30. The optical laminate of the present invention is not prone to blurring, residual adhesive, etc. on the surface of the metal layer 30 after the optical film 1 with an adhesive is peeled from the metal layer 30, and has excellent reprocessability. The optical laminate according to the present invention can show good reprocessability even when the surface to which the adhesive layer 20 is bonded is not the metal layer 30 but a glass substrate or an ITO layer.

[0176] <Image display device>

[0177] The image display device of the present invention includes the optical layered body of the present invention. The image display device of the present invention can suppress corrosion of the metal layer 30 and exhibit good durability.

[0178] Example

[0179] The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples. In the Examples, "parts" and "%" indicating the blending amount or content are based on mass unless otherwise specified.

[0180] In the following examples, the solid content (non-volatile component) is expressed as the ratio of the mass of the residual non-volatile component to the mass of the solution initially measured after an acrylic resin solution is taken in a petri dish with an arbitrary mass and dried in an explosion-proof oven at 120°C for 4 hours. In addition, the weight average molecular weight Mw is measured as follows: In a GPC device, two "TSKgel GMHHR-H (S)" manufactured by Tosoh Corporation are connected in series as columns, and tetrahydrofuran is used as an eluent. The standard polystyrene conversion is performed under the conditions of a sample concentration of 2 mg / mL, a sample introduction amount of 100 μL, a temperature of 40°C, and a flow rate of 1 mL / min.

[0181] [Preparation of acrylic resin solutions (1) to (5)]

[0182] (Acrylic resin solution (1))

[0183] A monomer mixture prepared by diluting 42.5 parts by mass of n-butyl acrylate, 5 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of methyl acrylate, 30 parts by mass of 2-methoxyethyl acrylate, 1.0 parts by mass of 2-hydroxyethyl acrylate and 1.5 parts by mass of acrylic acid with ethyl acetate was added to a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer, and the internal temperature was raised to 55° C. while replacing the air in the apparatus with nitrogen to exclude oxygen. Then, a solution prepared by dissolving azobisisobutyronitrile in ethyl acetate as a polymerization initiator was added so that the amount of azobisisobutyronitrile was 0.3 parts by mass relative to 100 parts by mass of the total amount of the monomers. After the addition of the polymerization initiator, the temperature was maintained at 55° C. for 1 hour, and then ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts / hr while the internal temperature was maintained at 54 to 56° C. The addition of ethyl acetate was stopped when the concentration of the acrylic resin reached 35%, and the temperature was further maintained at 55° C. until 12 hours had passed since the addition of ethyl acetate was started. Then, ethyl acetate was added to adjust the concentration of the acrylic resin to 20%, thereby preparing an acrylic resin solution (1). Table 1 shows the weight average molecular weight Mw of the obtained acrylic resin.

[0184] (Acrylic resin solutions (2) to (5))

[0185] Acrylic resin solutions (2) to (5) were obtained in the same manner as in the preparation of acrylic resin solution (1) except that the monomer compositions were set as shown in Table 1. Table 1 shows the weight average molecular weights Mw of the obtained acrylic resins.

[0186] [Preparation of Adhesive Compositions (1) to (15)]

[0187] (Adhesive composition (1))

[0188] To 100 parts by mass of the solid content of the acrylic resin solution (1) obtained above, 0.5 parts by mass, based on the effective ingredients, of an ethyl acetate solution (solid content concentration 75% by mass) of "D-103" (a trimethylolpropane adduct of toluene diisocyanate) manufactured by Mitsui Chemicals, Inc. as a crosslinking agent, 0.5 parts by mass, based on the effective ingredients, of a silane compound "KBM-403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and 0.54 parts by mass, based on the effective ingredients, of tributylmethylammonium bis(trifluoromethanesulfonyl)imide as an ionic compound were added, and ethyl acetate was further added so that the solid content concentration became 14%, thereby obtaining an adhesive composition (1).

[0189] (Adhesive compositions (2) to (15))

[0190] Adhesive compositions (2) to (15) were obtained in the same manner as in the preparation of the adhesive composition (1), except that the acrylic resin solution and the ionic compound described in Table 2 were used and the amount of the ionic compound based on the active ingredient was set to the amount shown in Table 2 (the amount relative to 100 parts by mass of the solid content of the acrylic resin solution).

[0191] [Production of Adhesive Sheets (1) to (15)]

[0192] (Adhesive sheet (1))

[0193] The adhesive composition (1) obtained above was applied to the release-treated surface of a release film (1) (manufactured by Mitsubishi Chemical Co., Ltd., trade name "MRV38 (V04)", thickness: 38 μm) using an applicator so that the thickness after drying became 15 μm, and then dried at a temperature of 100° C. for 1 minute to obtain an adhesive layer (1) with a thickness of 15 μm. A release film (2) (manufactured by Mitsubishi Chemical Co., Ltd., trade name "MRF38", thickness: 38 μm) was laminated on the side of the obtained adhesive layer (1) opposite to the release film (1) so that the release-treated surface became the side of the adhesive layer (1). The obtained laminate was allowed to stand for more than 7 days under an environment of a temperature of 23° C. and a relative humidity of 60%, to obtain an adhesive sheet (1).

[0194] (Adhesive sheets (2) to (15))

[0195] PSA sheets (2) to (15) were obtained in the same manner as in the preparation of the PSA sheet (1) except that PSA compositions (2) to (15) were used.

[0196] [Table 1]

[0197]

[0198] BA: n-butyl acrylate

[0199] 2EHA: 2-Ethylhexyl acrylate

[0200] MA: Methyl acrylate

[0201] MEA: 2-Methoxyethyl acrylate

[0202] HEA: 2-Hydroxyethyl Acrylate

[0203] AA: Acrylic acid

[0204] [Table 2]

[0205]

[0206] [Production of polarizing plate (1)]

[0207] A polyvinyl alcohol resin film (average degree of polymerization of about 2400, degree of saponification of 99.9 mol % or more) with a thickness of 30 μm was longitudinally uniaxially stretched to about 5 times by dry stretching, and then immersed in pure water at a temperature of 60°C for 1 minute while maintaining the tension, and then immersed in an aqueous solution at a temperature of 28°C with a mass ratio of iodine / potassium iodide / water of 0.05 / 5 / 100 for 60 seconds. Then, it was immersed in an aqueous solution at a temperature of 72°C with a mass ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 for 300 seconds. Subsequently, after washing with pure water at a temperature of 26°C for 20 seconds, it was dried at a temperature of 65°C to obtain a polarizing plate (1) having a linear polarizing layer with a thickness of 12 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol resin film.

[0208] [Preparation of the first protective film]

[0209] As the first protective film (1), a triacetyl cellulose (TAC) film (thickness: 25 μm) was prepared. Also, as the first protective film (2), a film (total thickness: 32 μm) was prepared in which a hard coating layer with a thickness of 7 μm was formed on one side of the triacetyl cellulose (TAC) film (thickness: 25 μm).

[0210] [Preparation of the second protective film]

[0211] As the second protective film (1), a cycloolefin resin (COP) film (thickness: 13 μm) was prepared. Also, as the second protective film (2), a triacetyl cellulose (TAC) film (thickness: 20 μm) was prepared. Also, as the second protective film (3), a triacetyl cellulose (TAC) film (thickness: 25 μm) was prepared.

[0212] [Production of Polarizing Plate (1)]

[0213] A corona treatment is applied to one surface of each of the first protective film (1) and the second protective film (1). A water-based adhesive is applied to one surface of the polarizer (1), and the first protective film (1) is bonded thereto. A water-based adhesive is applied to the other surface of the polarizer (1), and the second protective film (1) is bonded thereto. Then, the polarizer (1) is obtained by drying it. The water-based adhesive is obtained by dissolving 3 parts of carboxyl-modified polyvinyl alcohol [trade name "KL-318" obtained from Kuraray Co., Ltd.] in 100 parts of water, and adding 1.5 parts of a polyamide epoxy additive as a water-soluble epoxy resin [trade name "Sumirez Resin 650 (30)" manufactured by Tanaoka Chemical Industry Co., Ltd., a 30% solid content concentration aqueous solution]. Through the above operation, a linear polarizing plate, i.e., a polarizing plate (1) comprising the first protective film (1) / adhesive layer / polarizer (1) / adhesive layer / second protective film (1) is obtained.

[0214] [Production of Polarizing Plate (2)]

[0215] A corona treatment is applied to one surface of the first protective film (1) and the second protective film (2). A water-based adhesive is applied to one surface of the polarizer (1), and the first protective film (1) is attached. A water-based adhesive is applied to the other surface of the polarizer (1), and the second protective film (2) is attached. Then, it is dried to obtain a polarizing plate (2). Through the above operation, a linear polarizing plate, i.e., a polarizing plate (2), comprising the first protective film (1) / adhesive layer / polarizer (1) / adhesive layer / second protective film (2) is obtained.

[0216] [Production of Polarizing Plate (3)]

[0217] A corona treatment is applied to one surface of the first protective film (2) and the second protective film (3). A water-based adhesive is applied to one surface of the polarizer (1), and the first protective film (2) is attached. A water-based adhesive is applied to the other surface of the polarizer (1), and the second protective film (3) is attached. Then, it is dried to obtain a polarizing plate (3). Through the above operation, a linear polarizing plate, i.e., a polarizing plate (3), comprising the first protective film (2) / adhesive layer / polarizer (1) / adhesive layer / second protective film (3) is obtained.

[0218] [Production of Phase Element (1)]

[0219] (1) Preparation of Laminated Body A

[0220] (1-1) Preparation of Photo-Alignment Film-Forming Composition A

[0221] The photo-alignment material of the following structure (weight average molecular weight: 50000, m:n=50:50) was prepared according to the method described in Japanese Patent Application Publication No. 2021-196514. 2 parts of the photo-alignment material and 98 parts of cyclopentanone (solvent) were mixed as components, and the obtained mixture was stirred at 80° C. for 1 hour to prepare a photo-alignment film-forming composition A.

[0222] Photo-oriented materials:

[0223] [Chemical formula 7]

[0224]

[0225] (1-2) Production of polymerizable liquid crystal compound

[0226] A polymerizable liquid crystal compound (A1) and a polymerizable liquid crystal compound (A2) having the structures shown below were prepared respectively. The polymerizable liquid crystal compound (A1) was prepared in the same manner as described in Japanese Patent Publication No. 2019-003177. The polymerizable liquid crystal compound (A2) was prepared in the same manner as described in Japanese Patent Publication No. 2009-173893.

[0227] Polymerizable liquid crystal compound (A1):

[0228] [Chemical formula 8]

[0229]

[0230] Polymerizable liquid crystal compound (A2):

[0231] [Chemical formula 9]

[0232]

[0233] 1 mg of polymerizable liquid crystal compound (A1) was dissolved in 10 mL of chloroform to obtain a solution. The obtained solution was added to a measuring cuvette with an optical path length of 1 cm as a measuring sample, and the measuring sample was set in an ultraviolet visible spectrophotometer ("UV-2450" manufactured by Shimadzu Corporation) to measure the absorption spectrum. The wavelength reaching the maximum absorbance was read from the obtained absorption spectrum, and the maximum absorption wavelength λmax in the range of 300 to 400 nm was 356 nm.

[0234] (1-3) Preparation of Phase Difference Film Forming Composition A

[0235] The polymerizable liquid crystal compound (A1) and the polymerizable liquid crystal compound (A2) were mixed in a mass ratio of 90:10 to obtain a mixture. 0.1 parts of a leveling agent "BYK-361N" (manufactured by BM Chemie) and 3 parts of "Irgacure OXE-03" (manufactured by BASF Japan Co., Ltd.) as a photopolymerization initiator were added to 100 parts of the obtained mixture. In addition, N-methyl-2-pyrrolidone (NMP) was added in such a way that the solid content concentration became 13%. The mixture was stirred at a temperature of 80°C for 1 hour to prepare a phase difference film forming composition A.

[0236] (1-4) Preparation of Phase Difference Film A

[0237] The composition A for forming a photo-alignment film was applied to a biaxially stretched polyethylene terephthalate (PET) film (DIAFOIL; manufactured by Mitsubishi Plastics Co., Ltd.) as a substrate A using a rod coater. The obtained coating film was dried at 120°C for 2 minutes and then cooled to room temperature to form a dry film. Then, a UV irradiation device (SPOT CURESP-9; manufactured by USHIO Electric Co., Ltd.) was used to irradiate 100 mJ of polarized ultraviolet light (based on 313 nm) to obtain a photo-alignment film A. The film thickness of the photo-alignment film A measured using an ellipsometer M-220 manufactured by JASCO Corporation was 100 nm.

[0238] The above-mentioned phase difference film forming composition A was applied to the obtained photo-alignment film A using a rod coater to form a coating film. The coating film was heated and dried at 120°C for 2 minutes and then cooled to room temperature to obtain a dry film. Next, a high-pressure mercury lamp ("Unicure VB-15201BY-A" manufactured by USHIO Electric Co., Ltd.) was used to irradiate the above-mentioned dry film in a nitrogen atmosphere with an exposure amount of 500mJ / cm 2 The polymerizable liquid crystal compound was oriented in the horizontal direction relative to the substrate surface by ultraviolet light (based on 365 nm), thereby forming a phase difference film A that was cured, and a laminate A including substrate A / photo-aligned film A / phase difference film A was obtained. The film thickness of the phase difference film A measured using a laser microscope LEXTOLS4100 manufactured by Olympus Corporation was 2.0 μm.

[0239] The surface of the phase difference film A of the stack A was subjected to corona treatment, and the laminate was bonded to glass via a 25 μm thick adhesive layer, and the substrate A was peeled off and removed. The in-plane phase difference values ​​of the stack of the photo-alignment film A / phase difference film A with respect to light of wavelengths of 450 nm, 550 nm, and 650 nm were obtained based on the Cauchy dispersion formula obtained from the measurement results of the in-plane phase difference values ​​with respect to light of wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm.

[0240] As a result, the in-plane retardation values ​​were Re(450)=122 nm, Re(550)=140 nm, and Re(650)=144 nm, and the relationship between the in-plane retardation values ​​at each wavelength was as follows.

[0241] Re(450) / Re(550)=0.87

[0242] Re(650) / Re(550)=1.03

[0243] (Wherein, Re(450) represents the in-plane phase difference value relative to light with a wavelength of 450 nm, Re(550) represents the in-plane phase difference value relative to light with a wavelength of 550 nm, and Re(650) represents the in-plane phase difference value relative to light with a wavelength of 650 nm.)

[0244] (2) Preparation of Laminated Body B

[0245] (2-1) Preparation of Alignment Film Forming Composition B

[0246] 2-Butoxyethanol was added to Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is a commercially available aligning polymer, so that the solid content became 1%, thereby obtaining an alignment film-forming composition B.

[0247] (2-2) Preparation of Phase Difference Film Forming Composition B

[0248] 100 parts of the polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan) having the structure shown below, 0.1 parts of the leveling agent "BYK-361N" (manufactured by BYK-Chemie) and 2.5 parts of the photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV) were mixed. In addition, 400 parts of propylene glycol 1-monomethyl ether 2-acetate (PGME) were added, and the obtained mixture was stirred at a temperature of 80° C. for 1 hour to prepare a phase difference film forming composition B.

[0249] Polymerizable liquid crystal compound LC242:

[0250] [Chemical formula 10]

[0251]

[0252] (2-3) Preparation of Phase Difference Film B

[0253] A cycloolefin resin (COP) film (ZF14, manufactured by ZEON Co., Ltd., Japan) was used as the substrate B. One side of the film was subjected to a corona treatment using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.). The composition B for forming an alignment film was applied to the surface using a bar coater and dried at 90° C. for 1 minute. The film thickness of the obtained alignment film B was measured using a laser microscope and found to be 30 nm.

[0254] The retardation film forming composition B was applied to the obtained oriented film B using a bar coater and dried at 90°C for 1 minute to obtain a dry film. The dry film was irradiated with an exposure dose of 1000 mJ / cm2 using a high pressure mercury lamp ("Unicure VB-15201BY-A" manufactured by USHIO Electric Co., Ltd.) in a nitrogen atmosphere. 2 The retardation film B was formed by applying ultraviolet light (based on 365 nm) to obtain a laminate B including substrate B / alignment film B / retardation film B. The film thickness of the retardation film B measured using a laser microscope LEXTOLS4100 manufactured by Olympus Corporation was 450 nm.

[0255] The phase difference of the laminate B was measured, and the results showed that Re(550)=1nm, Rth(550)=-75nm. The laminate B has the optical characteristics shown by nx≈ny<nz. It should be noted that the phase difference at the wavelength of 550nm of COP is approximately 0, so it has no effect on the optical characteristics.

[0256] (3) Fabrication of Phase Element (1)

[0257] (3-1) Preparation of active energy ray-curable adhesive (1)

[0258] The following components were blended and mixed, and then degassed to prepare an active energy ray-curable adhesive (1) (hereinafter, simply referred to as "adhesive (1)").

[0259] (Cationically polymerizable compound)

[0260] 3',4'-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation): 70 parts

[0261] Neopentyl glycol diglycidyl ether (trade name: EX-211, manufactured by Nagase ChemteX Co., Ltd.): 20 parts

[0262] 2-Ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Co., Ltd.): 10 parts

[0263] (Photocationic polymerization initiator)

[0264] Trade name: CPI-100 (manufactured by San-Apro Co., Ltd., 50% propylene carbonate solution): 4.5 parts (substantial solid content: 2.25 parts)

[0265] (Photosensitizing agent)

[0266] 1,4-Diethoxynaphthalene: 2 parts

[0267] (3-2) Fabrication of Phase Element (1)

[0268] The phase difference film A of the stack A and the phase difference film B of the stack B are subjected to corona treatment, respectively. An adhesive is applied to the corona-treated surface of either the phase difference film A or the phase difference film B, and the stack A and the stack B are bonded together. The adhesive (1) described above is used as the adhesive. The corona treatment device used is AGF-B10 manufactured by Kasuga Electric Co., Ltd. The corona treatment is performed once using the above-mentioned corona treatment device under the conditions of an output power of 0.3 kW and a treatment speed of 3 m / min. The adhesive (1) is cured by irradiating ultraviolet rays from the stack A side, forming an adhesive layer (1) with a thickness of 1.5 μm. The UVA with a wavelength of 320 nm to 390 nm becomes 420 mJ / cm 2 Through the above operation, a phase element with a substrate (1) comprising substrate A / photo-alignment film A / phase difference film A / adhesive layer (1) / phase difference film B / alignment film B / substrate B was prepared.

[0269] [Preparation of Interlayer Adhesive Layer (1)]

[0270] The interlayer adhesive layer (1) was prepared by the following procedure. The interlayer adhesive layer (1) was mainly used as an adhesive layer between the linear polarizing plate and the phase element in the examples described below.

[0271] (1) Preparation of acrylic resin solution (1) for interlayer adhesive

[0272] A mixed solution of 100 parts of ethyl acetate, 99.0 parts of butyl acrylate, 0.5 parts of 2-hydroxyethyl acrylate and 0.5 parts of acrylic acid was placed in a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer, and the internal temperature was raised to 55°C while replacing the air in the device with nitrogen to make it oxygen-free. Then, the entire amount of a solution prepared by dissolving 0.12 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. After adding the polymerization initiator, the temperature was maintained for 1 hour, and then ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts / hr while the internal temperature was maintained at 54-56°C. The addition of ethyl acetate was stopped at the moment when the concentration of the acrylic resin reached 35% by mass, and the temperature was further maintained at the same temperature until 6 hours had passed since the addition of ethyl acetate was started. Finally, ethyl acetate was added to adjust the concentration of the acrylic resin to 20% by mass, and an acrylic resin solution (1) for an interlayer adhesive was prepared. The weight average molecular weight Mw of the obtained acrylic resin was 1.7 million. It should be noted that Mw is measured as follows: In a GPC apparatus, two "TSKgel GMHHR-H(S)" manufactured by Tosoh Corporation are connected in series as columns, and tetrahydrofuran is used as an eluent. The measurement is performed by standard polystyrene conversion under the conditions of a sample concentration of 2 mg / mL, a sample introduction amount of 100 μL, a temperature of 40°C, and a flow rate of 1 mL / min.

[0273] (2) Preparation of interlayer adhesive composition (1)

[0274] To 80 parts of the solid content of the acrylic resin solution (1) for interlayer adhesive obtained in the above (1), 20 parts (solid content) of a difunctional acrylate (obtained from Shin-Nakamura Chemical Co., Ltd.; product number "A-DOG"), 2.5 parts of a crosslinking agent (Mitsui Chemicals: trade name "D-101E" (ethyl acetate solution of trimethylolpropane adduct of toluene diisocyanate (solid content concentration 75 mass %)) in terms of effective ingredients, 1.5 parts of a photopolymerization initiator (Ciba Specialty Chemicals: trade name "Irgacure 500"), and 0.3 parts of a silane coupling agent (Shin-Etsu Chemical Co., Ltd.: trade name "KBM-403") were added, and ethyl acetate was further added in such a manner that the solid content concentration became 13%, thereby obtaining an interlayer adhesive composition (1).

[0275] A-DOG is a diacrylate of an acetal compound of hydroxypivaldehyde and trimethylolpropane, and has the following structure.

[0276] [Chemical formula 11]

[0277]

[0278] (3) Preparation of interlayer adhesive layer (1)

[0279] Using an applicator, the interlayer adhesive composition (1) prepared in the above (2) was applied to the release-treated surface of a release film formed of a polyethylene terephthalate film [Mitsubishi Chemical: MRV (V04) (thickness: 38 μm)] that had been subjected to a release treatment, and dried at 100°C for 1 minute to produce an interlayer adhesive layer (adhesive sheet). Next, the surface of the obtained adhesive layer on the side opposite to the release film side was bonded to the release-treated surface of a release film formed of a polyethylene terephthalate film [Mitsubishi Chemical: MRF (thickness: 38 μm)] that had been subjected to a release treatment. Next, ultraviolet rays were irradiated under the following conditions to produce an interlayer adhesive layer (1). The storage modulus G' of the interlayer adhesive layer (1) at a temperature of 85°C was 0.125 MPa.

[0280] <UV irradiation conditions>

[0281] Fusion UV lamp system (Fusion UV Systems) was used. H Bulb UV wavelength range: UVA cumulative light quantity 250 mJ / cm 2 (Measurement device: measured value based on UV Power Puck II manufactured by FusionUV)

[0282] [Production of circular polarizing plate (1)]

[0283] The surface of the second protective film (1) of the above-mentioned polarizing plate (1) and the surface exposed by peeling off the substrate A of the phase element (1) are respectively subjected to corona treatment. The corona treatment device used is AGF-B10 manufactured by Kasuga Electric Co., Ltd. The corona treatment is performed once using the above-mentioned corona treatment device under the conditions of an output power of 0.3 kW and a treatment speed of 3 m / min. The corona-treated surface of the polarizing plate (1) and the corona-treated surface of the phase element (1) are bonded to each other with the aid of the above-mentioned interlayer adhesive layer (1). Then, the substrate B of the phase element (1) is peeled off and removed to obtain a circularly polarizing plate (1) comprising the first protective film (1) / adhesive layer / polarizer (1) / adhesive layer / second protective film (1) / interlayer adhesive layer (1) / photo-alignment film A / phase difference film A / adhesive layer (1) / phase difference film B / alignment film B in sequence.

[0284] [Production of circular polarizing plate (2)]

[0285] The surface of the second protective film (2) of the above-mentioned polarizing plate (2) and the surface exposed by peeling off the substrate A of the phase element (1) are respectively subjected to corona treatment. The corona treatment device used is AGF-B10 manufactured by Kasuga Electric Co., Ltd. The corona treatment is performed once using the above-mentioned corona treatment device under the conditions of an output power of 0.3 kW and a treatment speed of 3 m / min. The corona-treated surface of the polarizing plate (2) and the corona-treated surface of the phase element (1) are bonded together with the aid of the above-mentioned interlayer adhesive layer (1). Then, the substrate B of the phase element (1) is peeled off to obtain a circularly polarizing plate (2) comprising, in sequence, the first protective film (1) / adhesive layer / polarizer (1) / adhesive layer / second protective film (2) / interlayer adhesive layer (1) / photo-alignment film A / phase difference film A / adhesive layer (1) / phase difference film B / alignment film B.

[0286] [Production of circular polarizing plate (3)]

[0287] The surface of the second protective film (3) of the above-mentioned polarizing plate (3) and the surface exposed by peeling off the substrate A of the phase element (1) are respectively subjected to corona treatment. The corona treatment device used is AGF-B10 manufactured by Kasuga Electric Co., Ltd. The corona treatment is performed once under the conditions of an output power of 0.3 kW and a treatment speed of 3 m / min using the above-mentioned corona treatment device. The corona-treated surface of the polarizing plate (3) and the corona-treated surface of the phase element (1) are bonded together with the aid of the above-mentioned interlayer adhesive layer (1). Then, the substrate B of the phase element (1) is peeled off to obtain a circularly polarizing plate (3) comprising, in sequence, the first protective film (2) / adhesive layer / polarizer (1) / adhesive layer / second protective film (3) / interlayer adhesive layer (1) / photo-alignment film A / phase difference film A / adhesive layer (1) / phase difference film B / alignment film B.

[0288] [Table 3]

[0289] Circular polarizing plate Polarizing Plate Phase Element (1) (1) (1) (2) (2) (1) (3) (3) (1)

[0290] [Production of polarizing plate with adhesive]

[0291] (Example 1)

[0292] The release film (2) was peeled off from the pressure-sensitive adhesive sheet (1), and the exposed pressure-sensitive adhesive surface was corona-treated. Then, the surface of the retardation film B of the circularly polarizing plate (1) was bonded to the corona-treated surface, thereby obtaining a pressure-sensitive adhesive-attached circularly polarizing plate of Example 1.

[0293] (Examples 2 to 15 and Comparative Examples 1 to 9)

[0294] Polarizing plates with pressure-sensitive adhesive of Examples 2 to 15 and Comparative Examples 1 to 9 were obtained in the same manner as in the preparation of the circularly polarizing plate with pressure-sensitive adhesive of Example 1, except that the circularly polarizing plates and pressure-sensitive adhesive sheets shown in Table 4 were used.

[0295] [Evaluation of metal corrosion resistance]

[0296] A glass substrate with a metal layer (manufactured by GEOMATEC) is prepared in which a titanium and aluminum alloy layer with a thickness of about 500 nm is formed on the surface of the alkali-free glass by sputtering. The circular polarizing plate with adhesive obtained above is cut into a size of 30 mm × 30 mm, the release film (1) is peeled off, and the exposed adhesive surface is bonded to the metal layer. The plate is subjected to an autoclave treatment at a temperature of 50°C and a pressure of 0.49 MPa to prepare a test piece for metal corrosion evaluation. After the test piece for metal corrosion evaluation is stored in an environment with a temperature of 85°C and a relative humidity of 98% for 100 hours, light is irradiated from the glass side of the glass substrate with the metal layer, and the state of the metal layer of the test piece is observed from the surface of the polarizing plate side. When the area of ​​the metal layer bonded with the test piece at this time is defined as A1, and the area of ​​the portion of the metal layer bonded with the test piece through which light is transmitted due to corrosion is defined as A2, the proportion A of the corroded portion shown in the following formula is calculated. C [%] If this value is 1.8 or less, metal corrosion is considered to be appropriately suppressed, and if it is more preferably 1.5 or less, and further preferably 1.15 or less, metal corrosion can be considered to be further suppressed. The results are shown in Table 4.

[0297] [Mathematical formula 1]

[0298]

[0299] [Adhesion Evaluation]

[0300] The release film (2) was peeled off from the adhesive sheet obtained above, and the exposed adhesive surface was bonded to a PET film (thickness: 50 μm) to obtain a PET film with an adhesive. The obtained PET film with an adhesive was cut into a size of 25 mm × 120 mm, and the release film (1) was peeled off. After bonding the exposed adhesive surface to an alkali-free glass, it was subjected to an autoclave treatment at a temperature of 50°C and a pressure of 0.49 MPa to obtain a test piece for evaluating the adhesive strength. After the test piece for evaluating the adhesive strength was stored at a temperature of 23°C and a relative humidity of 60% for 24 hours, the PET film and the adhesive layer were peeled off from the alkali-free glass at a peeling angle of 180° and a peeling speed of 0.3 m / min using an Autograph (manufactured by Shimadzu Corporation, trade name "AGS-X (50N)"). The test force at this time was averaged in the peeling interval to be used as the adhesive strength. When the adhesive strength is 1 N / 25 mm or more, problems such as peeling during an impact test can be appropriately suppressed, and when it is 3 N / 25 mm or more, and even more preferably 5 N / 25 mm or more, problems can be further suppressed.

[0301] [Surface resistance evaluation]

[0302] The release film (2) was peeled off from the adhesive sheet obtained above, and the exposed adhesive surface was bonded to a PET film (thickness: 50 μm) to obtain a PET film with an adhesive. The obtained PET film with an adhesive was cut into a size of 40 mm×40 mm, and the release film (1) was peeled off. The probe of a surface resistance value measuring device (manufactured by Mitsubishi Chemical Corporation, trade name "Hiresta-UP MCP-HT450") was brought into contact with the exposed adhesive surface to measure the surface resistance value. The measurement conditions were set to apply a voltage of 100 V and an application time of 30 seconds. It should be noted that under the measurement conditions described, the surface resistance value was 1.0×10 12 If the surface resistance is 1.0×10 13 Ω / □ or less, the occurrence of defects caused by charging during the peeling of the peeling film can be suppressed, and more preferably 1.0×10 12 Ω / □ or less, more preferably 5.0×10 11 Ω / □, thereby being able to suppress the inconvenience caused by static electricity. The results are shown in Table 4.

[0303] [Table 4]

[0304]

Claims

1. An adhesive composition comprising a (meth)acrylic resin A-1 and an ionic compound A-2, The (meth)acrylic resin A-1 contains 10% by mass or more and 40% by mass or less of a structural unit derived from an alkoxyalkyl (meth)acrylate based on the total amount of structural units constituting the (meth)acrylic resin A-1, The ionic compound A-2 is an ionic compound comprising an anion part represented by the following formula (A-2-1) and an organic cation, In the formula, R 4 and R 5 Each independently represents a perfluoroalkyl group having 1 to 4 carbon atoms, or represents R 4 With R 5 A perfluoroalkylene group having 1 to 8 carbon atoms formed by bonding.

2. The adhesive composition according to claim 1, wherein The structural unit derived from the alkoxyalkyl (meth)acrylate includes a structural unit derived from a (meth)acrylate represented by the following formula (A-1-1), In the formula, R 1 represents a hydrogen atom or a methyl group, R 2 represents an alkylene group having 1 to 4 carbon atoms, R 3 It represents an alkyl group having 1 to 4 carbon atoms.

3. The adhesive composition according to claim 1, wherein The (meth)acrylic resin A-1 contains 0.6% by mass or more and 10% by mass or less of a structural unit derived from a carboxyl group-containing monomer based on the total amount of structural units constituting the (meth)acrylic resin A-1.

4. The adhesive composition according to claim 1, wherein The (meth)acrylic resin A-1 includes a structural unit derived from a (meth)acrylate represented by the following formula (A-1-2): In the formula, R 6 represents a hydrogen atom or a methyl group, R 7 It represents an alkyl group or an aralkyl group having 1 to 14 carbon atoms.

5. The adhesive composition according to claim 4, wherein The (meth)acrylic resin A-1 contains 5% by mass or more and 50% by mass or less of the structural units constituting the (meth)acrylic resin A-1, which are derived from the R 7 A structural unit of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms.

6. The adhesive composition according to claim 1, wherein The content of the ionic compound A-2 is 0.1 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the (meth)acrylic resin A-1.

7. The adhesive composition according to claim 1, wherein The melting point of the ionic compound A-2 is 23° C. or higher.

8. The adhesive composition according to claim 1, wherein The R of the anion portion of the ionic compound A-2 4 and R 5 All are trifluoromethyl.

9. The adhesive composition according to claim 1, wherein The organic cation of the ionic compound A-2 includes a nitrogen atom. 10 . An adhesive layer formed using the adhesive composition according to claim 1 . The pressure-sensitive adhesive layer according to claim 10 , which has a thickness of 2 μm to 50 μm. 12 . A polarizing plate with an adhesive, comprising a polarizing plate bonded to the adhesive layer according to claim 10 .

13. The polarizing plate with adhesive according to claim 12, wherein The polarizing plate includes a phase element.

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