Adhesive sheet, optical laminate, and image display device

Abstract

Provided is an adhesive sheet formed from a photocurable composition, the adhesive sheet having a sufficiently low surface resistance value and being suitable for adjusting the anchoring force with an optical film to a large value. This adhesive sheet (1) is formed from a photocurable composition containing a monomer group and / or a partial polymer of the monomer group. In the adhesive sheet (1), at least one of the following (i) and (ii) is established: (i) the photocurable composition contains an ionic compound C having a functional group F capable of reacting with the monomer group and / or partial polymer; (ii) In the photocurable composition, a portion of the polymer and the ionic compound C are bonded together via a covalent bond. In the adhesive sheet (1), the ratio R1 determined by a corona treatment test is 2.0 or less.

Description

Technical Field

[0001] The present invention relates to an adhesive sheet, an optical laminate, and an image display device. Background Art

[0002] Various image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices generally include an optical laminate including optical films such as a polarizing film and an adhesive sheet. For the bonding between the optical films contained in the optical laminate and the bonding between the optical laminate and the image display panel, an adhesive sheet is usually used.

[0003] In the case of an image display device, static electricity is generated during its manufacture (for example, when an optical laminate is attached to an image display unit via an adhesive sheet) or during use (for example, when a user touches the image display device). If the image display device is charged due to this static electricity, problems such as poor display may occur. Patent Document 1 discloses the following: In order to prevent the charging of an image display device, a conductive agent (antistatic agent) is added to the adhesive sheet.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-187365 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] A general adhesive sheet can be manufactured by, for example, the following thermal curing method. First, a crosslinking agent or the like is added to a polymer produced by polymerizing a polymerizable monomer in an organic solvent to prepare an adhesive composition. The adhesive composition is applied to a substrate such as a release liner, and the organic solvent is removed by heating to form a sheet. If necessary, heat curing is performed to complete crosslinking, thereby enabling the manufacture of an adhesive sheet. In this manufacturing process, in order to generate the heat energy required for removing the organic solvent by heating and heat curing, it is necessary to burn a large amount of fuels such as LNG. In addition, if the organic solvent after being removed by heating is directly discharged into the atmosphere, there is a risk of causing serious adverse effects on the surrounding environment. Therefore, in most cases, the organic solvent is burned in a deodorizing furnace or the like before being released. In this case, not only is more fuel required for burning in the deodorizing furnace, but also the organic solvent itself is converted into CO2 by combustion and discharged into the atmosphere, which is a manufacturing process with a very large CO2 emission.

[0009] In recent years, climate change caused by greenhouse gases has become an urgent issue, and governments of various countries have set numerical targets and are working on CO2 reduction. In the manufacture of adhesive sheets, it is also required to select a manufacturing process that does not use organic solvents and has a low CO2 emission.

[0010] Compared with the above-mentioned thermal curing method, the method of producing an adhesive sheet using light (photo-curing method) can reduce the energy and CO2 emissions required for forming the adhesive sheet. However, according to the research by the present inventors, when producing an adhesive sheet by the photo-curing method, if the adhesive sheet contains a conductive agent, there is a tendency for the anchoring force between the adhesive sheet and the optical film to decrease. If the anchoring force decreases, peeling may occur between the adhesive sheet and the optical film.

[0011] Therefore, the present invention provides an adhesive sheet formed from a photo-curable composition, which has a sufficiently low surface resistance value and is suitable for adjusting the anchoring force with an optical film to a relatively large value.

[0012] Method for solving the problem

[0013] According to the research by the present inventors, when the adhesive sheet is subjected to surface modification treatment such as corona treatment, the anchoring force with the optical film sometimes increases. However, the present inventors newly found through in-depth research that if the existing adhesive sheet containing a conductive agent is subjected to surface modification treatment, unevenness in thickness will be caused, which will instead lead to a decrease in the anchoring force. Based on this insight, the present inventors conducted research and thus completed the present invention.

[0014] The present invention provides an adhesive sheet formed from a photo-curable composition containing a monomer group and / or a partial polymer of the above monomer group,

[0015] wherein at least one of the following (i) and (ii) holds:

[0016] (i) The above photo-curable composition contains an ionic compound having a functional group capable of reacting with the above monomer group and / or the above partial polymer;

[0017] (ii) In the above photo-curable composition, the above partial polymer and the above ionic compound are bonded together via a covalent bond,

[0018] The ratio R1 obtained by the following test is 2.0 or less,

[0019] Test: With a discharge amount of 3.8 kJ / m 2 One surface of the above adhesive sheet is subjected to corona treatment, the maximum film thickness TH1 and the minimum film thickness TL1 of the adhesive sheet after the above corona treatment are determined, and the ratio R1 of the above maximum film thickness TH1 to the above minimum film thickness TL1 is determined.

[0020] In addition, the present invention provides an adhesive sheet formed from a photo-curable composition containing a monomer group and / or a partial polymer of the above monomer group,

[0021] At least one of the following (i) and (ii) holds:

[0022] (i) The above photocurable composition contains an ionic compound having a functional group capable of reacting with the above monomer group and / or the above partial polymer;

[0023] (ii) In the above photocurable composition, the above partial polymer and the above ionic compound are bonded together via a covalent bond,

[0024] The above adhesive sheet has a surface that has been subjected to a surface modification treatment,

[0025] The ratio of the maximum film thickness to the minimum film thickness of the above adhesive sheet is 2.0 or less.

[0026] Furthermore, the present invention provides an optical laminate comprising:

[0027] The above adhesive sheet, and

[0028] An optical film containing at least one selected from a polarizing film and a retardation film.

[0029] Furthermore, the present invention provides an image display device comprising the above optical laminate.

[0030] Effects of the Invention

[0031] According to the present invention, it is possible to provide an adhesive sheet formed from a photocurable composition, the surface resistance value of which is sufficiently low and which is suitable for adjusting the anchoring force to an optical film to a large value. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a cross-sectional view schematically showing an example of the adhesive sheet of the present invention.

[0033] Figure 2A is a schematic diagram for explaining an example of the manufacturing method of the adhesive sheet of the present invention.

[0034] Figure 2B is a schematic diagram for explaining an example of the manufacturing method of the adhesive sheet of the present invention.

[0035] Figure 2C is a schematic diagram for explaining an example of the manufacturing method of the adhesive sheet of the present invention.

[0036] Figure 3 is a cross-sectional view schematically showing an example of the optical laminate of the present invention.

[0037] Figure 4 is a cross-sectional view schematically showing an example of the optical laminate of the present invention.

[0038] Figure 5 This is an image showing the result of corona treatment on the surface of the adhesive sheet of Comparative Example 1. Detailed implementation mode

[0039] The adhesive sheet of the first mode of the present invention is formed from a photocurable composition containing a monomer group and / or a partial polymer of the above monomer group,

[0040] wherein at least one of the following (i) and (ii) holds:

[0041] (i) The above photocurable composition contains an ionic compound having a functional group capable of reacting with the above monomer group and / or the above partial polymer;

[0042] (ii) In the above photocurable composition, the above partial polymer and the above ionic compound are bonded together via a covalent bond,

[0043] The ratio R1 obtained by the following test is 2.0 or less.

[0044] Test: With a discharge amount of 3.8 kJ / m 2 Corona treatment is performed on one surface of the above adhesive sheet. The maximum film thickness TH1 and the minimum film thickness TL1 of the above adhesive sheet after the above corona treatment are determined. The ratio R1 of the above maximum film thickness TH1 to the above minimum film thickness TL1 is determined.

[0045] In the second mode of the present invention, for example, in the adhesive sheet of the first mode, the ratio R1 is 1.3 or less.

[0046] In the third mode of the present invention, for example, in the adhesive sheet of the first or second mode, the above minimum film thickness TL1 is 10 μm or more.

[0047] In the fourth mode of the present invention, for example, in the adhesive sheet of any one of the first to third modes, the ratio R2 of the maximum film thickness TH2 to the minimum film thickness TL2 of the above adhesive sheet before the above test is 1.5 or less.

[0048] In the fifth mode of the present invention, for example, in the adhesive sheet of any one of the first to fourth modes, the above functional group is at least one selected from (meth)acryloyloxy, (meth)acrylamino, vinyl, allyl, styryl, hydroxyl, amino, mercapto, and epoxy groups.

[0049] In the sixth mode of the present invention, for example, in the adhesive sheet of any one of the first to fifth modes, the above ionic compound has an anion and a cation, and among the above anion and the above cation, only the above cation has the above functional group.

[0050] In the seventh aspect of the present invention, for example, in the adhesive sheet of any one of the first to sixth aspects, the monomer group contains an ether group-containing monomer.

[0051] In the eighth aspect of the present invention, for example, in the adhesive sheet of any one of the first to seventh aspects, the photocurable composition does not contain an isocyanate crosslinking agent.

[0052] In the ninth aspect of the present invention, for example, in the adhesive sheet of any one of the first to eighth aspects, in the photocurable composition, the blending amount of the ionic compound is 0.1 parts by weight or more with respect to the total 100 parts by weight of the monomer group and the partial polymer.

[0053] In the tenth aspect of the present invention, for example, in the adhesive sheet of any one of the first to ninth aspects, the content rate of the solvent in the photocurable composition is 5% by weight or less.

[0054] In the eleventh aspect of the present invention, for example, the adhesive sheet of any one of the first to tenth aspects has a surface that has been subjected to a surface modification treatment.

[0055] In the twelfth aspect of the present invention, for example, the surface resistance value of the adhesive sheet of any one of the first to eleventh aspects is 1.0×10 13 Ω / □ or less.

[0056] In the thirteenth aspect of the present invention, for example, the glass transition temperature of the adhesive sheet of any one of the first to twelfth aspects is -60°C to 25°C.

[0057] In the fourteenth aspect of the present invention, for example, the storage modulus G' of the adhesive sheet of any one of the first to thirteenth aspects at 25°C is 1.0×10 3 Pa to 1.0×10 6 Pa.

[0058] The adhesive sheet of the fifteenth aspect of the present invention is formed from a photocurable composition containing a monomer group and / or a partial polymer of the monomer group,

[0059] wherein at least one of the following (i) and (ii) holds:

[0060] (i) The photocurable composition contains an ionic compound having a functional group capable of reacting with the monomer group and / or the partial polymer;

[0061] (ii) In the photocurable composition, the partial polymer and the ionic compound are bonded together via a covalent bond,

[0062] The above-mentioned adhesive sheet has a surface that has been subjected to surface modification treatment.

[0063] The ratio of the maximum film thickness to the minimum film thickness of the above-mentioned adhesive sheet is 2.0 or less.

[0064] The optical laminate of the 16th aspect of the present invention includes:

[0065] The adhesive sheet of any one of the 1st to 15th aspects, and

[0066] An optical film containing at least one selected from a polarizing film and a retardation film.

[0067] In the 17th aspect of the present invention, for example, in the optical laminate of the 16th aspect, the anchoring force between the above-mentioned adhesive sheet and the above-mentioned optical film is 10.0 N / 25 mm or more.

[0068] The image display device of the 18th aspect of the present invention includes the optical laminate of the 16th or 17th aspect.

[0069] Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following embodiments and can be arbitrarily modified and implemented without departing from the gist of the present invention.

[0070] [Embodiment of Adhesive Sheet]

[0071] An example of the adhesive sheet of the present embodiment is shown in Figure 1 . Figure 1 The adhesive sheet 1 is formed of a photocurable composition containing a monomer group and / or a partial polymer of the monomer group. In the adhesive sheet 1, at least one of the following (i) and (ii) holds: (i) the photocurable composition contains an ionic compound C having a functional group F capable of reacting with the above-mentioned monomer group and / or partial polymer; (ii) in the photocurable composition, the partial polymer and the ionic compound C are bonded together via a covalent bond.

[0072] In the present embodiment, the ratio R1 obtained by the following test is 2.0 or less.

[0073] Test: Corona-treat one surface of the adhesive sheet 1 with a discharge amount of 3.8 kJ / m 2 Determine the maximum film thickness TH1 and the minimum film thickness TL1 of the adhesive sheet 1 after the corona treatment. Determine the ratio R1 of the maximum film thickness TH1 to the minimum film thickness TL1.

[0074] The above tests are conducted, for example, by the following method. First, an adhesive sheet 1 is prepared and passed through a processing apparatus for corona treatment. As an example, the adhesive sheet 1 is transported along the length direction of the adhesive sheet 1 and passed through the processing apparatus. The speed at which the adhesive sheet 1 passes through the processing apparatus is, for example, 3 m / min. In the processing apparatus, active energy rays are irradiated onto one surface (e.g., surface 1a) of the adhesive sheet 1 under the condition of a discharge amount of 3.8 kJ / m 2 to perform corona treatment. It should be noted that the inside of the processing apparatus is adjusted to an inert gas atmosphere such as nitrogen or argon, for example.

[0075] Next, the film thickness of the adhesive sheet 1 after corona treatment is measured. The film thickness of the adhesive sheet 1 is measured as follows: using, for example, a precision thickness gauge, etc., the distance between the mutually opposite surfaces 1a and 1b of the adhesive sheet 1 is measured along a direction orthogonal to the direction of movement in the processing apparatus (e.g., the width direction of the adhesive sheet 1). For the measured distances of surfaces 1a and 1b, the maximum value is regarded as the maximum film thickness TH1 of the adhesive sheet 1, and the minimum value is regarded as the minimum film thickness TL1 of the adhesive sheet 1. Based on this result, the ratio R1 (TH1 / TL1) of the maximum film thickness TH1 to the minimum film thickness TL1 can be determined.

[0076] It should be noted that according to the research of the present inventors, etc., if a surface modification treatment such as corona treatment is performed on an existing adhesive sheet containing a conductive agent, there is a tendency for striped thickness unevenness to occur in the adhesive sheet. This thickness unevenness is formed, for example, along the moving direction of the adhesive sheet in the processing apparatus, and at the position of this thickness unevenness, the film thickness of the adhesive sheet increases significantly. If thickness unevenness occurs, not only will there be problems with optical properties, but also there is a tendency for the anchoring force with the optical film to be significantly reduced. In the adhesive sheet 1 of the present embodiment, the above ratio R1 is 2.0 or less, and the occurrence of thickness unevenness caused by the surface modification treatment is suppressed. Therefore, the adhesive sheet 1 of the present embodiment is suitable for adjusting the anchoring force with the optical film to a larger value by surface modification treatment.

[0077] In the present embodiment, as described above, the ratio R1 is 2.0 or less, preferably 1.8 or less, and can be 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, and further can be 1.1 or less. The lower limit of the ratio R1 is not particularly limited, for example, it is greater than 1.0.

[0078] The minimum film thickness TL1 is, for example, 5 μm or more, and may be 10 μm or more, 15 μm or more, 20 μm or more, and further may be 25 μm or more. The upper limit of the minimum film thickness TL1 is not particularly limited. For example, it is 500 μm or less, and may be 300 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, and further may be 50 μm or less. As the numerical range of the maximum film thickness TH1, the numerical ranges described above for the minimum film thickness TL1 can be cited.

[0079] It should be noted that, in the present embodiment, for the adhesive sheet 1 before the above-mentioned test, it is preferable that the ratio R2 (TH2 / TL2) of the maximum film thickness TH2 to the minimum film thickness TL2 is low. The ratio R2 is preferably 1.5 or less, and may be 1.4 or less, 1.3 or less, 1.2 or less, and further may be 1.1 or less. The lower limit of the ratio R2 is not particularly limited. For example, it is greater than 1.0.

[0080] The maximum film thickness TH2 and the minimum film thickness TL2 of the adhesive sheet 1 before the above-mentioned test can be measured by the same method as described above using a precision thickness gauge or the like. The minimum film thickness TL2 is, for example, 5 μm or more, and may also be 10 μm or more, 15 μm or more, 20 μm or more, and further may be 25 μm or more. The upper limit of the minimum film thickness TL2 is not particularly limited. For example, it is 500 μm or less, and may also be 300 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, and further may be 50 μm or less. As the numerical range of the maximum film thickness TH2, the numerical ranges described above for the minimum film thickness TL2 can be cited.

[0081] (Photocurable composition)

[0082] As described above, the adhesive sheet 1 is formed of a photocurable composition. The photocurable composition is an adhesive composition that forms the adhesive sheet 1 by irradiating light. In the photocurable composition, the monomer component contains, for example, (meth)acrylic monomers. The content of the (meth)acrylic component in the photocurable composition, that is, the (meth)acrylic monomers and their partial polymers, can be 50% by weight or more, 60% by weight or more, 70% by weight or more, and further can be 80% by weight or more. In this case, an acrylic adhesive sheet 1 mainly composed of (meth)acrylic polymers and their crosslinked products can be formed. However, the photocurable composition is not limited to the above examples. In the present specification, (meth)acrylic acid means acrylic acid and methacrylic acid. (Meth)acrylate means acrylate and methacrylate.

[0083] Examples of the (meth)acrylic acid monomer are (meth)acrylic acid alkyl esters having an alkyl group with 1 to 20 carbon atoms in the side chain. The number of carbon atoms in the alkyl group can be 4 to 18, can also be 7 or less, 6 or less, and further can be 5 or less. The alkyl group can be linear or branched. Examples of the (meth)acrylic acid alkyl ester are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, isostearyl (meth)acrylate. The (meth)acrylic acid alkyl ester can be n-butyl (meth)acrylate.

[0084] The compounding amount of the (meth)acrylic acid alkyl ester in 100 parts by weight of the monomer group is, for example, 10 parts by weight or more, and can also be 20 parts by weight or more, 30 parts by weight or more, 40 parts by weight or more, 50 parts by weight or more, 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, 85 parts by weight or more, 90 parts by weight or more, and further can be 95 parts by weight or more. Depending on the situation, the compounding amount of the (meth)acrylic acid alkyl ester can also be less than 10 parts by weight. The monomer group may not contain the (meth)acrylic acid alkyl ester. It should be noted that when calculating the compounding amount of a specific monomer, the weight of the partial polymer is converted into the weight based on each monomer before polymerization.

[0085] The monomer group may contain a carboxyl group-containing monomer. The carboxyl group-containing monomer may be a (meth)acrylic acid monomer. In other words, the (meth)acrylic acid monomer may contain a carboxyl group-containing monomer. Examples of the carboxyl group-containing monomer are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. The compounding amount of the carboxyl group-containing monomer in 100 parts by weight of the monomer group is, for example, 10 parts by weight or less, and may be 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, and further may be 0.5 parts by weight or less. The lower limit of the compounding amount is, for example, 0.1 parts by weight or more, and depending on the situation, may also be 0.5 parts by weight or more. The monomer group may also not contain a carboxyl group-containing monomer.

[0086] The monomer group may contain a hydroxyl group-containing monomer. The hydroxyl group-containing monomer may be a (meth)acrylic acid monomer. In other words, the (meth)acrylic acid monomer may contain a hydroxyl group-containing monomer. The hydroxyl group-containing monomer may contribute to the improvement of the cohesion of the adhesive sheet. Examples of the hydroxyl group-containing monomer are 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl acrylate. The hydroxyl group-containing monomer is preferably 4-hydroxybutyl (meth)acrylate. The compounding amount of the hydroxyl group-containing monomer in 100 parts by weight of the monomer group is, for example, 30 parts by weight or less, and may also be 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 7.5 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, and further may be 2 parts by weight or less. The lower limit of the compounding amount is, for example, 0.01 parts by weight or more, and may also be 0.03 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, and further may be 1 part by weight or more. The monomer group may also not contain a hydroxyl group-containing monomer.

[0087] The monomer group may contain an amide group-containing monomer. The amide group-containing monomer may be a (meth)acrylic monomer. In other words, the (meth)acrylic monomer may contain an amide group-containing monomer. Examples of the amide group-containing monomer are acrylamide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, N-hydroxymethyl-N-propyl(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, mercaptoethyl(meth)acrylamide, etc.; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, etc.; N-vinyl lactam monomers containing N-vinyl such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, etc. The amide group-containing monomer is preferably N-vinylpyrrolidone. The compounding amount of the amide group-containing monomer in 100 parts by weight of the monomer group is, for example, 30 parts by weight or less, and may also be 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 7.5 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, and further may be 2 parts by weight or less. The lower limit of the compounding amount is, for example, 0.01 part by weight or more, and may also be 0.03 part by weight or more, 0.05 part by weight or more, 0.1 part by weight or more, and further may be 1 part by weight or more. The monomer group may also not contain an amide group-containing monomer.

[0088] The monomer group may contain an ether group-containing monomer. The ether group-containing monomer may be a (meth)acrylic monomer. In other words, the (meth)acrylic monomer may contain an ether group-containing monomer. The ether group-containing monomer may contribute to the improvement of the anchoring force between the adhesive sheet 1 and the optical film and the reduction of the surface resistance value of the adhesive sheet 1.

[0089] The ether group-containing monomer preferably contains an alkoxy group-containing monomer. The alkoxy group-containing monomer is, for example, an alkylene oxide adduct represented by the following formula (1). R in formula (1) 1 is a hydrogen atom or a methyl group. R in formula (1) 2 is an alkyl group. The alkyl group may be linear or may have a branched chain. R 2 is preferably a linear alkyl group. Examples of R 2 are a methyl group and an ethyl group. n in formula (1) is an integer of 1 to 30, preferably an integer of 1 to 12, and may be an integer of 1 to 5.

[0090] [Chemical formula 1]

[0091]

[0092] Examples of the alkylene oxide adduct represented by the formula (1) are 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxypolyethylene glycol (meth)acrylate. Preferred are 2-methoxyethyl acrylate (MEA) and 2-(2-ethoxyethoxy)ethyl acrylate (CBA: ethyl carbitol acrylate).

[0093] The ether group-containing monomer is not limited to the above alkylene oxide adduct. The ether group-containing monomer may have a ring structure, and the ring structure may have an ether group. Examples of the ring structure having an ether group include a tetrahydrofuran ring and a dioxane ring. Examples of the ether group-containing monomer having a ring structure are cyclic trimethylolpropane formal (meth)acrylate and tetrahydrofurfuryl (meth)acrylate.

[0094] The blending amount of the ether group-containing monomer in 100 parts by weight of the monomer group is, for example, 1 part by weight or more, and may be 5 parts by weight or more, 10 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 40 parts by weight or more, 50 parts by weight or more, 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, and further may be 90 parts by weight or more. The upper limit of the blending amount is, for example, 99 parts by weight or less, and depending on the situation, may be 50 parts by weight or less. The monomer group may not contain an ether group-containing monomer.

[0095] The monomer group may also contain other monomers other than (meth)acrylic acid alkyl esters, carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, and ether group-containing monomers. Examples of other monomers include aromatic ring-containing monomers such as benzyl (meth)acrylate.

[0096] In the photocurable composition, the above-mentioned respective monomers may be contained in the form of a partial polymer. The partial polymer may be any polymer among homopolymers and copolymers. The partial polymer can help the stable formation of the coating layer described later by moderately increasing the viscosity of the photocurable composition. The weight average molecular weight of the partial polymer is, for example, 500,000 or more, preferably 800,000 to 3,000,000.

[0097] As described above, in the present embodiment, at least one of the following (i) and (ii) holds: (i) The photocurable composition contains an ionic compound C having a functional group F capable of reacting with the above monomer group and / or partial polymer; (ii) In the photocurable composition, the partial polymer and the ionic compound C are bonded together via a covalent bond.

[0098] When the above requirement (i) is satisfied, the ionic compound C reacts with the monomer group and the partial polymer via the functional group F, for example, during the curing of the photocurable composition. As an example, the functional group F is a polymerizable functional group, and the ionic compound C functions as a monomer and reacts with the monomer group and the partial polymer. In this case, a crosslinked product of the polymer and the partial polymer of the monomer group having a structural unit derived from the ionic compound C introduced into the main chain can be obtained. It should be noted that the ionic compound C can react with the functional group located on the side chain of the polymer and the crosslinked product of the partial polymer of the monomer group. In this case, a crosslinked product of the polymer and the partial polymer of the monomer group having the ionic compound C introduced into the side chain can be obtained.

[0099] In the above requirement (ii), the ionic compound C can be introduced into the main chain of the partial polymer. In other words, the partial polymer can have a structural unit derived from the ionic compound C in the main chain. Such a partial polymer can be prepared by reacting the ionic compound C having a polymerizable functional group as the functional group F with the above monomer group. It should be noted that the ionic compound C can be bonded to the partial polymer via a covalent bond formed by reacting with the functional group located on the side chain of the partial polymer.

[0100] When requirements (i) and (ii) are satisfied, in the adhesive sheet formed from the photocurable composition, the ionic compound C is introduced into the polymer and the crosslinked product of the partial polymer of the monomer group. As an example, a structural unit derived from the ionic compound C is introduced into the polymer and the crosslinked product of the partial polymer of the monomer group. The polymer and the crosslinked product into which the ionic compound C is introduced are suitable for reducing the surface resistance value of the adhesive sheet 1. In addition, by introducing the ionic compound C into the polymer and the crosslinked product, the segregation of the ionic compound C in the adhesive sheet 1 is suppressed. Based on this, in the adhesive sheet 1, there is a tendency to suppress the occurrence of thickness unevenness during surface modification treatment such as corona treatment.

[0101] The ionic compound C is preferably an ionic liquid present in a liquid form at 25 °C, but it may not be an ionic liquid. The functional group F contained in the ionic compound C is, for example, at least one selected from (meth)acryloyloxy, (meth)acryloylamino, vinyl, allyl, styryl, hydroxyl, amino (primary amino, secondary amino), mercapto, and epoxy groups. The functional group F is preferably (meth)acryloyloxy, (meth)acryloylamino, or hydroxyl, and particularly preferably (meth)acryloyloxy.

[0102] In the ionic compound C, the number of the functional groups F is not particularly limited, and is, for example, 1 to 4, may be 1 to 3, may be 1 or 2, or may be 1. When the ionic compound C has a plurality of functional groups F, the plurality of functional groups F may be the same or different. It should be noted that the ionic compound C having a plurality of functional groups F can also function as a crosslinking agent.

[0103] The ionic compound C usually has an anion and a cation. In the ionic compound C, it may be that the anion has the functional group F, or the cation has the functional group F, or both the anion and the cation have the functional group F. In the ionic compound C, it is preferred that only the cation has the functional group F among the anion and the cation.

[0104] In the ionic compound C, examples of the anion include SCN - , BF4 - , PF6 - , NO3 - , CH3COO - , CF3COO - , CH3SO3 - , CF3SO3 - , (FSO2)2N - , (CF3SO2)2N - , (CF3SO2) 3 C - , AsF6 - , SbF6 - , NbF6 - , TaF6 - , F(HF) n - , (CN)2N - , C4F9SO3 - , (C2F5SO2)2N - , C3F7COO - , (CF3SO2)(CF3CO)N - , B(CN)4 - , C(CN)3 - , N(CN)2 - , CH3OSO3 - , C2H5OSO3 - , C4H9OSO3 - , C6H 13 OSO3 - , C8H 17 OSO3 - , p-toluenesulfonate anion, 2-(2-methoxyethyl)ethyl sulfate anion, (C2F5)3PF3- etc. In particular, an anionic component containing a fluorine atom (fluorine-containing anions) lowers the melting point of the ionic compound C and has excellent antistatic properties, and is thus preferred. It is preferred that the ionic compound C contains (FSO2)2N - , (CF3SO2)2N - etc. as fluorine-containing anions. It should be noted that from the viewpoint of corrosion, it is preferred that the ionic compound C does not contain chloride ions, bromide ions, etc. as anions.

[0105] In the ionic compound C, examples of the cation include: quaternary ammonium cations, imidazole cations, pyridine cations, piperidine cations, pyrrolidine cations, quaternary cations, trialkylsulfonium cations, pyrrole cations, pyrazole cations, guanidine cations, and their derivatives (especially derivatives having a functional group F). It is preferred that the ionic compound C contains quaternary ammonium cations, imidazole cations, pyridine cations, piperidine cations, pyrrolidine cations, quaternary cations, derivatives such as trialkylsulfonium cations as cations.

[0106] The ionic compound C is represented, for example, by the following formula (2).

[0107] [Chemical formula 2]

[0108]

[0109] In formula (2), Y - is an anion, and X + is a cation. Z 1 and Z 2 are independently a single bond or an alkylene group having 1 to 16 carbon atoms. A 1 and A 2 are independently the above functional group F. n 1 is 0 or 1, and n 2 is 0 or 1. Among them, n 1 +n 2 is 1 or 2.

[0110] As Y - , for example, the above anions can be cited. As X + , quaternary ammonium groups, imidazole groups, pyridine groups, piperidine Base, pyrrolidine Base, pyrrolyl, quaternary Base, trialkylsulfonium, pyrazole Base, guanidyl, etc. When X + is a quaternary ammonium group, the adhesive sheet 1 tends to have excellent transparency and be suitable for electronic / optical applications. The quaternary ammonium group also tends not to hinder general free radical polymerization reactions during ultraviolet (UV) curing and to improve the curability of the photocurable composition.

[0111] In the above-mentioned n 1 +n 2 is 1, examples of the quaternary ammonium group include: trimethylammonium group, triethylammonium group, tripropylammonium group, methyldiethylammonium group, ethyldimethylammonium group, methyldipropylammonium group, dimethylbenzylammonium group, diethylbenzylammonium group, methyldibenzylammonium group, ethyldibenzylammonium group, dimethyloctadecylammonium group, dimethyloleylammonium group, etc. From the viewpoint of obtaining inexpensive industrial materials, the quaternary ammonium group is preferably a trimethylammonium group, a dimethylbenzylammonium group, etc.

[0112] In the above-mentioned n 1 +n 2 is 2, examples of the quaternary ammonium group include: dimethylammonium group, diethylammonium group, dipropylammonium group, methylethylammonium group, methylpropylammonium group, methylbenzylammonium group, ethylbenzylammonium group, methyloctadecylammonium group, ethyloctadecylammonium group, methyloleylammonium, ethyloleylammonium group, etc. From the viewpoint of obtaining inexpensive industrial materials, the quaternary ammonium group is preferably a dimethylammonium group, a methyloleylammonium group, etc.

[0113] As described above, Z 1 and Z 2 are independently a single bond or an alkylene group having 1 to 16 carbon atoms. The number of carbon atoms of the alkylene group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 3. Examples of the alkylene group include: methylene, ethylene, trimethylene, methylethylene, etc., and ethylene and trimethylene are preferred.

[0114] As described above, A 1 and A 2 are independently the above-mentioned functional group F. A 1 and A 2 are preferably (meth)acryloyloxy, (meth)acrylamino or hydroxy, and particularly preferably (meth)acryloyloxy.

[0115] As X in the above formula (2) + is a quaternary ammonium group, n 1 is 1, n 2 is 0, A 1Examples of the ionic compound C having a vinyl group, a (meth)acryloyloxy group or a (meth)acrylamino group include: ionic compounds containing an N,N,N-trialkyl-N-vinylammonium cation such as N,N,N-trialkyl-N-vinylammonium tetrafluoroborate, N,N,N-trialkyl-N-vinylammonium trifluoroacetate, N,N,N-trialkyl-N-vinylammonium heptafluorobutyrate, N,N,N-trialkyl-N-vinylammonium trifluoromethanesulfonate, N,N,N-trialkyl-N-vinylammonium perfluorobutanesulfonate, N,N,N-trialkyl-N-vinylammonium bis(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-vinylammonium bis(pentafluoroethanesulfonyl)imide, N,N,N-trialkyl-N-vinylammonium tris(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-vinylammonium hexafluorophosphate, N,N,N-trialkyl-N-vinylammonium (trifluoromethanesulfonyl)trifluoroacetamide, N,N,N-trialkyl-N-vinylammonium dicyanamide, N,N,N-trialkyl-N-vinylammonium thiocyanate; ionic compounds containing an N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium cation such as N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium tetrafluoroborate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium trifluoroacetate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium heptafluorobutyrate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium trifluoromethanesulfonate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium perfluorobutanesulfonate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium bis(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium bis(pentafluoroethanesulfonyl)imide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium tris(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium hexafluorophosphate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium (trifluoromethanesulfonyl)trifluoroacetamide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium dicyanamide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium thiocyanate;Ionic compounds containing N,N,N-trialkyl-N-(methacryloylamino)alkylammonium cations, such as N,N,N-trialkyl-N-(methacryloylamino)alkylammonium tetrafluoroborate, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium trifluoroacetate, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium heptafluorobutyrate, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium trifluoromethanesulfonate, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium perfluorobutanesulfonate, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium bis(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium bis(pentafluoroethanesulfonyl)imide, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium tris(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium hexafluorophosphate, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium (trifluoromethanesulfonyl)trifluoroacetamide, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium dicyanamide, N,N,N-trialkyl-N-(methacryloylamino)alkylammonium thiocyanate, etc. It should be noted that in these compounds, the number of carbon atoms of the alkyl substituent is preferably 1 to 16, more preferably 1 to 12, and further preferably 1 to 6.;

[0116] As X in the above formula (2) + is a quaternary ammonium group, n 1 is 1, n 2 is 0, A 1 Specific examples of the ionic compound C in which (methacryloyloxy) is (methacryloyloxy) include: (methacryloyloxy)propyltrimethylammonium bis(trifluoromethanesulfonyl)imide, (methacryloyloxy)propyldimethylbenzylammonium bis(trifluoromethanesulfonyl)imide, (methacryloyloxy)ethyltrimethylammonium bis(trifluoromethanesulfonyl)imide, (methacryloyloxy)ethyldimethylbenzylammonium bis(trifluoromethanesulfonyl)imide, (methacryloyloxy)ethyltrimethylammonium bis(fluorosulfonyl)imide, (methacryloyloxy)ethyldimethylbenzylammonium bis(fluorosulfonyl)imide, (methacryloyloxy)ethyltrimethylammonium trifluoromethanesulfonate, (methacryloyloxy)ethyldimethylbenzylammonium trifluoromethanesulfonate, etc. As the ionic compound C, acryloyloxyethyltrimethylammonium bis(trifluoromethanesulfonyl)imide, acryloyloxyethyltrimethylammonium bis(fluorosulfonyl)imide, etc. are preferred.

[0117] As X in the above formula (2) + is a quaternary ammonium group, n 1 is 1, n 2 is 0, A 1Specific examples of the ionic compound C having a (meth)acrylamido group include: (meth)acrylamidopropyltrimethylammonium bis(trifluoromethanesulfonyl)imide, (meth)acrylamidopropyldimethylbenzylammonium bis(trifluoromethanesulfonyl)imide, (meth)acrylamidopropyltrimethylammonium bis(fluorosulfonyl)imide, (meth)acrylamidopropyldimethylbenzylammonium bis(fluorosulfonyl)imide, (meth)acrylamidopropyltrimethylammonium trifluoromethanesulfonate, (meth)acrylamidopropyldimethylbenzylammonium trifluoromethanesulfonate, etc.

[0118] As X in the above formula (2) + is imidazole group, n 1 is 1 and n 2 is 0 or 1, A 1 and A 2 Examples of the ionic compound C where A and A are vinyl groups include: 1-alkyl-3-vinylimidazole tetrafluoroborate, 1-alkyl-3-vinylimidazole trifluoroacetate, 1-alkyl-3-vinylimidazole heptafluorobutyrate, 1-alkyl-3-vinylimidazole trifluoromethanesulfonate, 1-alkyl-3-vinylimidazole perfluorobutanesulfonate, 1-alkyl-3-vinylimidazole bis(trifluoromethanesulfonyl)imide, 1-alkyl-3-vinylimidazole bis(pentafluoroethanesulfonyl)imide, 1-alkyl-3-vinylimidazole tris(trifluoromethanesulfonyl)imide, 1-alkyl-3-vinylimidazole hexafluorophosphate, 1-alkyl-3-vinylimidazole (trifluoromethanesulfonyl)trifluoroacetamide, 1-alkyl-3-vinylimidazole dicyanamide, 1-alkyl-3-vinylimidazole thiocyanate, etc., ionic compounds containing 1-alkyl-3-vinylimidazole cation; 1,2-dialkyl-3-vinylimidazole bis(fluorosulfonyl)imide, 1,2-dialkyl-3-vinylimidazole bis(trifluoromethanesulfonyl)imide, 1,2-dialkyl-3-vinylimidazole dicyanamide, 1,2-dialkyl-3-vinylimidazole thiocyanate, etc., ionic compounds containing 1,2-dialkyl-3-vinylimidazole cation; 2-alkyl-1,3-divinylimidazole bis(fluorosulfonyl)imide, 2-alkyl-1,3-divinylimidazole Bis(trifluoromethanesulfonyl)imide, 2-alkyl-1,3-divinylimidazole Dicyanamide, 2-alkyl-1,3-divinylimidazole Ionic compounds containing 2-alkyl-1,3-divinylimidazole such as thiocyanate; 1-vinylimidazole cation; 1-vinylimidazole Bis(fluorosulfonyl)imide, 1-vinylimidazole Bis(trifluoromethanesulfonyl)imide, 1-vinylimidazole Dicyanamide, 1-vinylimidazole Ionic compounds containing 1-vinylimidazole such as thiocyanate etc. It should be noted that in these compounds, the number of carbon atoms of the alkyl substituent is preferably 1 to 16, more preferably 1 to 12, and further preferably 1 to 6.

[0119] As X in the above formula (2) + is imidazole group, n 1 is 1, n 2 is 0 or 1, A 1 and A 2 Examples of the ionic compound C where A is (meth)acryloyloxy include: 1-alkyl-3-(meth)acryloyloxyalkylimidazole Tetrafluoroborate, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Trifluoroacetate, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Heptafluorobutyrate, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Trifluoromethanesulfonate, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Perfluorobutanesulfonate, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Bis(trifluoromethanesulfonyl)imide, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Bis(pentafluoroethanesulfonyl)imide, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Tris(trifluoromethanesulfonyl)imide, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Hexafluorophosphate, 1-alkyl-3-(meth)acryloyloxyalkylimidazole (Trifluoromethanesulfonyl)trifluoroacetamide, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Dicyanamide, 1-alkyl-3-(meth)acryloyloxyalkylimidazole Ionic compounds containing 1-alkyl-3-(meth)acryloyloxyalkylimidazole such as thiocyanate Ionic compounds of cations; 1,2-dialkyl-3-(methyl)acryloyloxyalkylimidazoles Bis(fluorosulfonyl)imide, 1,2-dialkyl-3-(methyl)acryloyloxyalkylimidazoles Bis(trifluoromethanesulfonyl)imide, 1,2-dialkyl-3-(methyl)acryloyloxyalkylimidazoles Dicyanamide, 1,2-dialkyl-3-(methyl)acryloyloxyalkylimidazoles Thiocyanates, etc. containing 1,2-dialkyl-3-(methyl)acryloyloxyalkylimidazoles Ionic compounds of cations; 2-alkyl-1,3-di(methyl)acryloyloxyalkylimidazoles Bis(fluorosulfonyl)imide, 2-alkyl-1,3-di(methyl)acryloyloxyalkylimidazoles Bis(trifluoromethanesulfonyl)imide, 2-alkyl-1,3-di(methyl)acryloyloxyalkylimidazoles Dicyanamide, 2-alkyl-1,3-di(methyl)acryloyloxyimidazoles Thiocyanates, etc. containing 2-alkyl-1,3-di(methyl)acryloyloxyalkylimidazoles Ionic compounds of cations; 1-(methyl)acryloyloxyalkylimidazoles Bis(fluorosulfonyl)imide, 1-(methyl)acryloyloxyalkylimidazoles Bis(trifluoromethanesulfonyl)imide, 1-(methyl)acryloyloxyalkylimidazoles Dicyanamide, 1-(methyl)acryloyloxyalkylimidazoles Thiocyanates, etc. containing 1-(methyl)acryloyloxyalkylimidazoles Ionic compounds of cations, etc. It should be noted that in these compounds, the number of carbon atoms of the alkyl substituent is preferably 1 to 16, more preferably 1 to 12, and further preferably 1 to 6.

[0120] As X in the above formula (2) + is imidazole group, n 1 is 1, n 2 is 0 or 1, A 1 and A 2 Examples of the ionic compound C where A is (methyl)acrylamino include: 1-alkyl-3-(methyl)acrylaminoalkylimidazoles Tetrafluoroborate, 1-alkyl-3-(methyl)acrylaminoalkylimidazoles Trifluoroacetate, 1-alkyl-3-(methyl)acrylaminoalkylimidazoles Heptafluorobutyrate, 1-alkyl-3-(methyl)acrylaminoalkylimidazoles Trifluoromethanesulfonate, 1-alkyl-3-(methyl)acrylamidoalkylimidazole Perfluorobutanesulfonate, 1-alkyl-3-(methyl)acrylamidoalkylimidazole Bis(trifluoromethanesulfonyl)imide, 1-alkyl-3-(methyl)acrylamidoalkylimidazole Bis(pentafluoroethanesulfonyl)imide, 1-alkyl-3-(methyl)acrylamidoalkylimidazole Tris(trifluoromethanesulfonyl)imide, 1-alkyl-3-(methyl)acrylamidoalkylimidazole Hexafluorophosphate, 1-alkyl-3-(methyl)acrylamidoalkylimidazole (Trifluoromethanesulfonyl)trifluoroacetamide, 1-alkyl-3-(methyl)acrylamidoalkylimidazole Dicyanamide, 1-alkyl-3-(methyl)acrylamidoalkylimidazole Ionic compounds containing 1-alkyl-3-(methyl)acrylamidoalkylimidazole such as thiocyanate Ionic compounds with cations; 1,2-dialkyl-3-(methyl)acrylamidoalkylimidazole Bis(fluorosulfonyl)imide, 1,2-dialkyl-3-(methyl)acrylamidoalkylimidazole Bis(trifluoromethanesulfonyl)imide, 1,2-dialkyl-3-(methyl)acrylamidoalkylimidazole Dicyanamide, 1,2-dialkyl-3-(methyl)acrylamidoalkylimidazole Ionic compounds containing 1,2-dialkyl-3-(methyl)acrylamidoalkylimidazole such as thiocyanate Ionic compounds with cations; 2-alkyl-1,3-di(methyl)acrylamidoalkylimidazole Bis(fluorosulfonyl)imide, 2-alkyl-1,3-di(methyl)acrylamidoalkylimidazole Bis(trifluoromethanesulfonyl)imide, 2-alkyl-1,3-di(methyl)acrylamidoalkylimidazole Dicyanamide, 2-alkyl-1,3-di(methyl)acrylamidoimidazole Ionic compounds containing 2-alkyl-1,3-di(methyl)acrylamidoalkylimidazole such as thiocyanate Ionic compounds with cations; 1-(methyl)acrylamidoalkylimidazole Bis(fluorosulfonyl)imide, 1-(methyl)acrylamidoalkylimidazole Bis(trifluoromethanesulfonyl)imide, 1-(methyl)acrylamidoalkylimidazole Dicyanamide, 1-(methyl)acrylamidoalkylimidazole Ionic compounds containing 1-(methyl)acrylamidoalkylimidazole such as thiocyanate Ionic compounds of cations, etc. It should be noted that in these compounds, the number of carbon atoms in the alkyl substituent is preferably 1 to 16, more preferably 1 to 12, and further preferably 1 to 6.

[0121] As X in the above formula (2) + is pyridine group, n 1 is 1, n 2 is 0, A 1 is vinyl, (meth)acryloyloxy or (meth)acrylamido, examples of the ionic compound C include: 1-vinylpyridine bis(fluorosulfonyl)imide, 1-vinylpyridine bis(trifluoromethanesulfonyl)imide, 1-vinylpyridine dicyanamide, 1-vinylpyridine thiocyanate, etc. containing 1-vinylpyridine cationic ionic compounds; 1-(meth)acryloyloxyalkylpyridine bis(fluorosulfonyl)imide, 1-(meth)acryloyloxyalkylpyridine bis(trifluoromethanesulfonyl)imide, 1-(meth)acryloyloxyalkylpyridine dicyanamide, 1-(meth)acryloyloxyalkylpyridine thiocyanate, etc. containing 1-(meth)acryloyloxyalkylpyridine cationic ionic compounds; 1-(meth)acrylamidoalkylpyridine bis(fluorosulfonyl)imide, 1-(meth)acrylamidoalkylpyridine bis(trifluoromethanesulfonyl)imide, 1-(meth)acrylamidoalkylpyridine dicyanamide, 1-(meth)acrylamidoalkylpyridine thiocyanate, etc. containing 1-(meth)acrylamidoalkylpyridine cationic ionic compounds; 2-alkyl-1-vinylpyridine bis(fluorosulfonyl)imide, 2-alkyl-1-vinylpyridine bis(trifluoromethanesulfonyl)imide, 2-alkyl-1-vinylpyridine dicyanamide, 2-alkyl-1-vinylpyridine thiocyanate, etc. containing 2-alkyl-1-vinylpyridine cationic ionic compounds; 2-alkyl-1-(meth)acryloyloxyalkylpyridine bis(fluorosulfonyl)imide, 2-alkyl-1-(meth)acryloyloxyalkylpyridine Bis(trifluoromethanesulfonyl)imide, 2-alkyl-1-(methyl)acryloyloxyalkylpyridine Dicyanamide, 2-alkyl-1-(methyl)acryloyloxyalkylpyridine Thiocyanate, etc. containing 2-alkyl-1-(methyl)acryloyloxyalkylpyridine Ionic compounds containing cations; 2-alkyl-1-(methyl)acrylamidoalkylpyridine Bis(fluorosulfonyl)imide, 2-alkyl-1-(methyl)acrylamidoalkylpyridine Bis(trifluoromethanesulfonyl)imide, 2-alkyl-1-(methyl)acrylamidoalkylpyridine Dicyanamide, 2-alkyl-1-(methyl)acrylamidoalkylpyridine Thiocyanate, etc. containing 2-alkyl-1-(methyl)acrylamidoalkylpyridine Ionic compounds containing cations; 3-alkyl-1-vinylpyridine Bis(fluorosulfonyl)imide, 3-alkyl-1-vinylpyridine Bis(trifluoromethanesulfonyl)imide, 3-alkyl-1-vinylpyridine Dicyanamide, 3-alkyl-1-vinylpyridine Thiocyanate, etc. containing 3-alkyl-1-vinylpyridine Ionic compounds containing cations; 3-alkyl-1-(methyl)acryloyloxyalkylpyridine Bis(fluorosulfonyl)imide, 3-alkyl-1-(methyl)acryloyloxyalkylpyridine Bis(trifluoromethanesulfonyl)imide, 3-alkyl-1-(methyl)acryloyloxyalkylpyridine Dicyanamide, 3-alkyl-1-(methyl)acryloyloxyalkylpyridine Thiocyanate, etc. containing 3-alkyl-1-(methyl)acryloyloxyalkylpyridine Ionic compounds containing cations; 3-alkyl-1-(methyl)acrylamidoalkylpyridine Bis(fluorosulfonyl)imide, 3-alkyl-1-(methyl)acrylamidoalkylpyridine Bis(trifluoromethanesulfonyl)imide, 3-alkyl-1-(methyl)acrylamidoalkylpyridine Dicyanamide, 3-alkyl-1-(methyl)acrylamidoalkylpyridine Thiocyanate, etc. containing 3-alkyl-1-(methyl)acrylamidoalkylpyridine Ionic compounds containing cations; 4-alkyl-1-vinylpyridine Bis(fluorosulfonyl)imide, 4-alkyl-1-vinylpyridine Bis(trifluoromethanesulfonyl)imide, 4-alkyl-1-vinylpyridine Dicyanamide, 4-alkyl-1-vinylpyridine Ionic compounds containing 4-alkyl-1-vinylpyridine such as thiocyanate Ionic compounds containing a cation of 4-alkyl-1-(meth)acryloyloxyalkylpyridine Bis(fluorosulfonyl)imide, 4-alkyl-1-(meth)acryloyloxyalkylpyridine Bis(trifluoromethanesulfonyl)imide, 4-alkyl-1-(meth)acryloyloxyalkylpyridine Dicyanamide, 4-alkyl-1-(meth)acryloyloxyalkylpyridine Ionic compounds containing 4-alkyl-1-(meth)acryloyloxyalkylpyridine such as thiocyanate Ionic compounds containing a cation of 4-alkyl-1-(meth)acrylamidoalkylpyridine Bis(fluorosulfonyl)imide, 4-alkyl-1-(meth)acrylamidoalkylpyridine Bis(trifluoromethanesulfonyl)imide, 4-alkyl-1-(meth)acrylamidoalkylpyridine Dicyanamide, 4-alkyl-1-(meth)acrylamidoalkylpyridine Ionic compounds containing 4-alkyl-1-(meth)acrylamidoalkylpyridine such as thiocyanate Ionic compounds etc. It should be noted that in these compounds, the number of carbon atoms of the alkyl substituent is preferably 1-16, more preferably 1-12, and further preferably 1-6.

[0122] As X in the above formula (2) + is piperidine group, n 1 is 1, n 2 is 0, A 1 Examples of the ionic compound C where is vinyl, (meth)acryloyloxy or (meth)acrylamido include: 1-alkyl-1-vinylalkylpiperidine Bis(fluorosulfonyl)imide, 1-alkyl-1-vinylalkylpiperidine Bis(trifluoromethanesulfonyl)imide, 1-alkyl-1-vinylalkylpiperidine Dicyanamide, 1-alkyl-1-vinylalkylpiperidine Ionic compounds containing 1-alkyl-1-vinylalkylpiperidine such as thiocyanate Ionic compounds containing a cation of 1-alkyl-1-(meth)acryloyloxyalkylpiperidine Bis(fluorosulfonyl)imide, 1-alkyl-1-(meth)acryloyloxyalkylpiperidine Bis(trifluoromethanesulfonyl)imide, 1-alkyl-1-(methyl)acryloyloxyalkylpiperidine Dicyanamide, 1-alkyl-1-(methyl)acryloyloxyalkylpiperidine Ionic compounds containing 1-alkyl-1-(methyl)acryloyloxyalkylpiperidine such as thiocyanate Ionic compounds containing cations; 1-alkyl-1-(methyl)acrylamidoalkylpiperidine Bis(fluorosulfonyl)imide, 1-alkyl-1-(methyl)acrylamidoalkylpiperidine Bis(trifluoromethanesulfonyl)imide, 1-alkyl-1-(methyl)acrylamidoalkylpiperidine Dicyanamide, 1-alkyl-1-(methyl)acrylamidoalkylpiperidine Ionic compounds containing 1-alkyl-1-(methyl)acrylamidoalkylpiperidine such as thiocyanate Ionic compounds etc. It should be noted that in these compounds, the number of carbon atoms of the alkyl substituent is preferably 1 to 16, more preferably 1 to 12, and further preferably 1 to 6.

[0123] As X in the above formula (2) + Is pyrrolidine Group, n 1 Is 1, n 2 Is 0, A 1 Examples of the ionic compound C where is vinyl, (methyl)acryloyloxy or (methyl)acrylamido include: 1-alkyl-1-vinylalkylpyrrolidine Bis(fluorosulfonyl)imide, 1-alkyl-1-vinylalkylpyrrolidine Bis(trifluoromethanesulfonyl)imide, 1-alkyl-1-vinylalkylpyrrolidine Dicyanamide, 1-alkyl-1-vinylalkylpyrrolidine Ionic compounds containing 1-alkyl-1-vinylalkylpyrrolidine such as thiocyanate Ionic compounds containing cations; 1-alkyl-1-(methyl)acryloyloxyalkylpyrrolidine Bis(fluorosulfonyl)imide, 1-alkyl-1-(methyl)acryloyloxyalkylpyrrolidine Bis(trifluoromethanesulfonyl)imide, 1-alkyl-1-(methyl)acryloyloxyalkylpyrrolidine Dicyanamide, 1-alkyl-1-(methyl)acryloyloxyalkylpyrrolidine Ionic compounds containing 1-alkyl-1-(methyl)acryloyloxyalkylpyrrolidine such as thiocyanate Ionic compounds containing cations; 1-alkyl-1-(methyl)acrylamidoalkylpyrrolidine Bis(fluorosulfonyl)imide, 1-alkyl-1-(methyl)acrylamidoalkylpyrrolidine Bis(trifluoromethanesulfonyl)imide, 1-alkyl-1-(methyl)acrylamidoalkylpyrrolidine Dicyanamide, 1-alkyl-1-(methyl)acrylamidoalkylpyrrolidine Ionic compounds containing 1-alkyl-1-(methyl)acrylamidoalkylpyrrolidine such as thiocyanate Cationic ionic compounds and the like. It should be noted that in these compounds, the number of carbon atoms of the alkyl substituent is preferably 1 to 16, more preferably 1 to 12, and further preferably 1 to 6.

[0124] As X in the above formula (2) + Is a trialkylsulfonium group, n 1 Is 1, n 2 Is 0, A 1 Examples of the ionic compound C where is vinyl, (meth)acryloyloxy or (meth)acrylamido include: Ionic compounds containing a dialkyl(vinyl)sulfonium cation such as dialkyl(vinyl)sulfonium bis(fluorosulfonyl)imide, dialkyl(vinyl)sulfonium bis(trifluoromethanesulfonyl)imide, dialkyl(vinyl)sulfonium dicyanamide, dialkyl(vinyl)sulfonium thiocyanate; Ionic compounds containing a dialkyl((meth)acryloyloxyalkyl)sulfonium cation such as dialkyl((meth)acryloyloxyalkyl)sulfonium bis(fluorosulfonyl)imide, dialkyl((meth)acryloyloxyalkyl)sulfonium bis(trifluoromethanesulfonyl)imide, dialkyl((meth)acryloyloxyalkyl)sulfonium dicyanamide, dialkyl((meth)acryloyloxyalkyl)sulfonium thiocyanate; Ionic compounds containing a dialkyl((meth)acrylamidoalkyl)sulfonium cation such as dialkyl((meth)acrylamidoalkyl)sulfonium bis(fluorosulfonyl)imide, dialkyl((meth)acrylamidoalkyl)sulfonium bis(trifluoromethanesulfonyl)imide, dialkyl((meth)acrylamidoalkyl)sulfonium dicyanamide, dialkyl((meth)acrylamidoalkyl)sulfonium thiocyanate and the like. It should be noted that in these compounds, the number of carbon atoms of the alkyl substituent is preferably 1 to 16, more preferably 1 to 12, and further preferably 1 to 6.

[0125] As X in the above formula (2) + Is a quaternary Group, n 1 Is 1, n 2 Is 0, A 1 Examples of the ionic compound C where is vinyl, (meth)acryloyloxy or (meth)acrylamido include: Trialkyl(vinyl) Bis(fluorosulfonyl)imide, trialkyl(vinyl) Bis(trifluoromethanesulfonyl)imide, trialkyl(vinyl) Dicyanamide, trialkyl(vinyl) Ionic compounds containing trialkyl(vinyl) cations such as thiocyanate trialkyl((meth)acryloyloxyalkyl) bis(fluorosulfonyl)imide, trialkyl((meth)acryloyloxyalkyl) bis(trifluoromethanesulfonyl)imide, trialkyl((meth)acryloyloxyalkyl) Dicyanamide, trialkyl((meth)acryloyloxyalkyl) Ionic compounds containing trialkyl((meth)acryloyloxyalkyl) cations such as thiocyanate trialkyl((meth)acrylamidoalkyl) bis(fluorosulfonyl)imide, trialkyl((meth)acrylamidoalkyl) bis(trifluoromethanesulfonyl)imide, trialkyl((meth)acrylamidoalkyl) Dicyanamide, trialkyl((meth)acrylamidoalkyl) Ionic compounds containing trialkyl((meth)acrylamidoalkyl) cations such as thiocyanate Ionic compounds and the like. It should be noted that in these compounds, the number of carbon atoms of the alkyl substituent is preferably 1 to 16, more preferably 1 to 12, and further preferably 1 to 6.

[0126] As X in the above formula (2) + is a quaternary ammonium group, n 1 is 1, n 2 is 1, A 1 and A 2Specific examples of the ionic compound C having a hydroxyl group include: bis(2-hydroxyethyl)-methyl-octylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-decylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-dodecylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-tetradecylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-hexadecylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-octadecylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-(9-ene-octadecyl)ammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-octylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-decylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-dodecylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-tetradecylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-hexadecylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-octadecylammonium bis(trifluoromethanesulfonyl)imide, oleyl bis(2-hydroxyethyl)methylammonium bis(trifluoromethanesulfonyl)imide, oleyl-ethyl-bis(2-hydroxyethyl)ammonium bis(trifluoromethanesulfonyl)imide, and the like.

[0127] As X in the above formula (2) + is pyridine group, n 1 is 1, n 2 is 0, A 1 Specific examples of the ionic compound C having a hydroxyl group include: N-hydroxyethylpyridine bis(trifluoromethanesulfonyl)imide and the like.

[0128] As X in the above formula (2) + is imidazole group, n 1 is 1, n 2 is 0, A 1 Specific examples of the ionic compound C having a hydroxyl group include: 1-(2-hydroxyethyl)-3-methylimidazole bis(trifluoromethanesulfonyl)imide and the like.

[0129] As X in the above formula (2) + is imidazole group or quaternary ammonium group, n 1 is 1, n 2 is 0, A 1 and A 2 Specific examples of the ionic compound C having an amino group include: 1-aminopropyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide, 1-aminopropyl-3-methylimidazole Dicyandiamide, 1-aminopropyl-3-methylimidazole Tetrafluoroborate, 1-aminohexyl-3-methylimidazole Bis(trifluoromethanesulfonyl)imide, 1-aminohexyl-3-methylimidazole Dicyandiamide, 1-aminohexyl-3-methylimidazole Tetrafluoroborate, trimethylaminohexylammonium bis(trifluoromethanesulfonyl)imide, trimethylaminohexylammonium dicyandiamide, trimethylaminohexylammonium tetrafluoroborate, etc.

[0130] When the above-mentioned requirement (i) is satisfied, from the viewpoint of imparting sufficient antistatic properties to the adhesive sheet 1, the blending amount of the ionic compound C in the photocurable composition is, for example, 0.01 parts by weight or more, and may also be 0.05 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, 1.0 parts by weight or more, 2.0 parts by weight or more, 3.0 parts by weight or more, 4.0 parts by weight or more, 5.0 parts by weight or more, 6.0 parts by weight or more, 7.0 parts by weight or more, and further may be 9.0 parts by weight or more, based on 100 parts by weight in total of the monomer group and its partial polymer. The upper limit of the blending amount of the ionic compound C is not particularly limited, and from the viewpoints of the transparency, appearance, adhesion reliability, durability, etc. of the adhesive sheet 1, it is, for example, 50 parts by weight or less, and may also be 40 parts by weight or less, 30 parts by weight or less, 25 parts by weight or less, 20 parts by weight or less, 15 parts by weight or less, and further may be 10 parts by weight or less.

[0131] When the above-mentioned requirement (ii) is satisfied, the ratio of the ionic compound C to the partial polymer is, for example, 0.01% by weight or more, and may also be 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1.0% by weight or more, 2.0% by weight or more, and further may be 3.0% by weight or more. The upper limit of the content rate of this structural unit is not particularly limited, and is, for example, 50% by weight or less, and may also be 30% by weight or less, 10% by weight or less, and further may be 5% by weight or less.

[0132] The photocurable composition usually contains a photopolymerization initiator. Examples of the photopolymerization initiator are photo radical generators that generate radicals by visible light having a wavelength shorter than 450 nm and / or ultraviolet rays.

[0133] Examples of the photoinitiator include benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzoin dimethyl ether; substituted benzoin ethers such as anisoin methyl ether; substituted acetophenones such as 2,2 - diethoxyacetophenone and 2,2 - dimethoxy - 2 - phenylacetophenone; α - hydroxyalkyl phenyl ketones such as 1 - hydroxycyclohexyl phenyl ketone; substituted α - hydroxy ketones such as 2 - methyl - 2 - hydroxypropiophenone; aromatic sulfonyl chlorides such as 2 - naphthalenesulfonyl chloride; photoactive oximes such as 1 - phenyl - 1,1 - propanedione - 2 - (o - ethoxycarbonyl) - oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4 - phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4 - benzoyl - 4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert - butylperoxycarbonyl)benzophenone; thioxanthone compounds such as thioxanthone, 2 - chlorothioxanthone, 2 - methylthioxanthone, isopropylthioxanthone, 2,4 - diisopropylthioxanthone, 2,4 - diethylthioxanthone; triazine compounds such as 2,4,6 - trichloro - s - triazine, 2 - phenyl - 4,6 - bis(trichloromethyl) - s - triazine, 2 - (p - methoxyphenyl) - 4,6 - bis(trichloromethyl) - s - triazine, 2 - (p - tolyl) - 4,6 - bis(trichloromethyl) - s - triazine, 2 - piperonyl - 4,6 - bis(trichloromethyl) - s - triazine, 2,4 - bis(trichloromethyl) - 6 - styryl - s - triazine, 2 - (naphthalen - 1 - yl) - 4,6 - bis(trichloromethyl) - s - triazine, 2 - (4 - methoxynaphthalen - 1 - yl) - 4,6 - bis(trichloromethyl) - s - triazine, 2,4 - trichloromethyl - (piperonyl) - 6 - triazine, 2,4 - trichloromethyl - (4'-methoxystyryl) - 6 - triazine; oxime ester compounds such as 1,2 - octanedione, 1 - [4 - (phenylthio) -, 2 - (O - benzoyl oxime)] and O - (acetyl) - N - (1 - phenyl - 2 - oxo - 2 - (4'-methoxynaphthyl)ethylidene)hydroxylamine; phosphine compounds such as bis(2,4,6 - trimethylbenzoyl)phenylphosphine oxide and 2,4,6 - trimethylbenzoyldiphenylphosphine oxide; quinone compounds such as 9,10 - phenanthrenequinone, camphorquinone, and ethylanthraquinone; borate compounds; carbazole compounds; imidazole compounds; and titanocene compounds. The photocurable composition may contain one or more photoinitiators.

[0134] Based on a total of 100 parts by weight of the monomer group and its partial polymers, the compounding amount of the photoinitiator in the photocurable composition is, for example, 0.02 to 10 parts by weight, and can be 0.05 to 5 parts by weight.

[0135] The photocurable composition may contain a crosslinking agent. Examples of the crosslinking agent are polyfunctional monomers having two or more polymerizable functional groups in one molecule. The polyfunctional monomer may be a (meth)acrylic monomer. Examples of the polyfunctional monomer are monomers having two or more C═C bonds in one molecule, and monomers having one or more C═C bonds, one or more epoxy groups, aziridinyl groups, oxazolinyl groups, hydrazino groups, hydroxymethyl groups and other polymerizable functional groups in one molecule. The polyfunctional monomer is preferably a monomer having two or more C═C bonds in one molecule.

[0136] Examples of the polyfunctional monomer are: (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol diacrylate (NDDA), 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate and other polyfunctional acrylates (ester compounds formed by polyhydric alcohols and (meth)acrylic acid, etc.); allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, hexyl di(meth)acrylate. The polyfunctional monomer is preferably a polyfunctional acrylate, more preferably 1,9-nonanediol diacrylate, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate.

[0137] The crosslinking agent may contain other crosslinking agents in addition to the above polyfunctional monomers, or may not contain them. As other crosslinking agents, isocyanate crosslinking agents can be cited. The photocurable composition preferably does not contain isocyanate crosslinking agents as other crosslinking agents.

[0138] The photocurable composition may also contain additives other than those described above. Examples of the additives are chain transfer agents, rework improvers, corrosion inhibitors, silane coupling agents, viscosity modifiers, tackifiers, plasticizers, softeners, anti-aging agents, fillers, colorants, antioxidants, surfactants, antistatic agents and ultraviolet absorbers. The photocurable composition preferably does not contain other antistatic agents than the above-mentioned ionic compound C.

[0139] The content rate of the solvent in the photocurable composition is, for example, 5% by weight or less, and may be 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, and further may be 0.5% by weight or less. The photocurable composition may substantially not contain a solvent. Substantially not containing a solvent means that it is allowed to contain solvents, etc. from additives, etc. at a content rate of, for example, 0.1% by weight or less, preferably 0.05% by weight or less, and more preferably 0.01% by weight or less.

[0140] The viscosity of the photocurable composition is preferably 1 to 150 Pa·s. The photocurable composition having a viscosity within the above range is particularly suitable for forming the coating layer described later.

[0141] (Physical properties of the adhesive sheet)

[0142] The polymerization rate of the monomer group in the adhesive sheet 1 is preferably 90% or more, and may be 95% or more, 97% or more, 98% or more, and further may be 99% or more.

[0143] The gel fraction of the adhesive sheet 1 is, for example, 30% or more, and may be 50% or more, 70% or more, 75% or more, 80% or more, and further may be 85% or more. The upper limit of the gel fraction of the adhesive sheet 1 is, for example, 97% or less, and may be 95% or less.

[0144] In the present embodiment, by making at least one of the above-mentioned requirements (i) and (ii) hold, there is a tendency for the surface resistance value of the adhesive sheet 1 to be sufficiently low. The surface resistance value of the adhesive sheet 1 is, for example, 1.0×10 13 Ω / □ or less, and may be 5.0×10 12 Ω / □ or less, 1.0×10 12 Ω / □ or less, 5.0×10 11 Ω / □ or less, 1.0×10 11 Ω / □ or less, 5.0×10 10 Ω / □ or less, and further may be 1.0×10 10 Ω / □ or less. The lower limit of the surface resistance value of the adhesive sheet 1 is not particularly limited, and is, for example, 1.0×10 5 Ω / □ or more, and may be 1.0×10 6 Ω / □ or more, 1.0×10 7 Ω / □ or more, 1.0×10 8 Ω / □ or more, and further may be 1.0×10 9 Ω / □ or more. The surface resistance value of the adhesive sheet 1 can be measured based on the method specified in JIS K6911:1995.

[0145] Preferably, the adhesive sheet 1 has high transparency. When the thickness of the adhesive sheet 1 is 25 μm, the haze of the adhesive sheet 1 is, for example, 3% or less, may be 1% or less, 0.8% or less, and further may be 0.5% or less. The haze of the adhesive sheet 1 can be measured based on the method specified in JIS K7136:1981.

[0146] The total light transmittance of the adhesive sheet 1 in the visible light wavelength range is preferably 85% or more, more preferably 90% or more. The total light transmittance of the adhesive sheet 1 can be measured based on the method specified in JIS K7361-1:1997.

[0147] The storage modulus G' of the adhesive sheet 1 at 25 °C is not particularly limited. For example, it is 1.0×10 3 Pa to 1.0×10 6 Pa, preferably 1.0×10 4 Pa to 1.0×10 6 Pa.

[0148] The storage modulus G' of the adhesive sheet 1 at 25 °C can be determined by the following method. First, prepare a measurement sample formed of the material constituting the adhesive sheet 1. The shape of the measurement sample is disc-shaped. The diameter of the bottom surface of the measurement sample is 8 mm, and the thickness is 1 mm. The measurement sample can be a sample obtained by punching a laminate in which a plurality of adhesive sheets 1 are laminated into a disc shape. Next, perform dynamic viscoelasticity measurement on the measurement sample. For dynamic viscoelasticity measurement, for example, "ARES-G2" manufactured by TA Instruments can be used. Based on the results of the dynamic viscoelasticity measurement, the storage modulus G' of the adhesive sheet 1 at 25 °C can be determined. It should be noted that the conditions for dynamic viscoelasticity measurement are as follows.

[0149] · Measurement conditions

[0150] Frequency: 1 Hz

[0151] Deformation mode: Torsion

[0152] Measurement temperature: -70 °C to 150 °C

[0153] Heating rate: 5 °C / min

[0154] The glass transition temperature (Tg) of the adhesive sheet 1 is not particularly limited. For example, it is -60 °C to 25 °C, may be -50 °C or higher, and further may be -45 °C or higher. The upper limit of the Tg of the adhesive sheet 1 can be 0 °C or lower, may be -10 °C or lower, and further may be -20 °C or lower.

[0155] In this specification, the Tg of the adhesive sheet 1 is the peak of tanδ (loss tangent). It should be noted that tanδ can be calculated according to the following formula based on the storage modulus G’ and loss modulus G” of the adhesive sheet 1. The storage modulus G’ and loss modulus G” of the adhesive sheet 1 can be determined by the above-described dynamic viscoelasticity measurement.

[0156] tanδ (loss tangent) = G” / G’

[0157] As Figure 1 shown, the adhesive sheet 1 has surfaces 1a and 1b that face each other. As an example, the adhesive sheet 1 is pasted on the optical film via the surface 1a, and the adhesive sheet 1 is pasted on the image display panel via the surface 1b. The surface 1a of the adhesive sheet 1 that contacts the optical film may or may not be subjected to a surface modification treatment. Depending on the surface 1a that has been subjected to the surface modification treatment, there is a tendency to increase the anchoring force between the adhesive sheet 1 and the optical film. On the other hand, it is preferable that the surface 1b of the adhesive sheet 1 is not subjected to a surface modification treatment. Examples of the surface modification treatment include corona treatment, plasma treatment, excimer treatment, and flame treatment. The surface 1a is preferably subjected to corona treatment as the surface modification treatment.

[0158] The surface modification treatment can be carried out in an inert gas atmosphere. By performing the surface modification treatment in a state where the oxygen concentration is reduced by an inert gas, the risk of ignition of residual monomers can be reduced. Specifically, it is preferable to perform the surface modification treatment at an oxygen concentration of 8 vol% or less, more preferably 6 vol% or less, and further preferably 3 vol% or less. If the oxygen concentration is too low, the introduction of functional groups to the surface of the adhesive sheet by the surface modification treatment may become insufficient. Therefore, the oxygen concentration is preferably 0.01 vol% or more, more preferably 0.1 vol% or more, and particularly preferably 0.5 vol% or more. Specific examples of the inert gas include nitrogen and argon. The surface modification treatment can be carried out at normal pressure (1 atmosphere).

[0159] The conditions of the surface modification treatment by corona treatment are represented by the discharge amount, for example, 0.6 to 100 kJ / m 2 . The lower limit of the discharge amount can be 1 kJ / m 2 or more, 2 kJ / m 2 or more, 5 kJ / m 2 or more, 7 kJ / m 2 or more, 10 kJ / m 2 or more, 13 kJ / m 2 or more, 15 kJ / m 2 or more, 20 kJ / m 2 or more, 25 kJ / m 2 or more, 30 kJ / m 2Above, it can further be 35 kJ / m 2 Above. The upper limit of the discharge amount can be 70 kJ / m 2 or less, 60 kJ / m 2 or less, 50 kJ / m 2 or less, 45 kJ / m 2 or less, 40 kJ / m 2 or less, 30 kJ / m 2 or less, 20 kJ / m 2 or less, and it can further be 18 kJ / m 2 or less. When the corona treatment is carried out in an atmosphere with an oxygen concentration of 10 vol% or more and 20.9 vol% or less, the discharge amount can be 1 to 18 kJ / m 2 When the corona treatment is carried out in an atmosphere with an oxygen concentration of 0.01 vol% or more and less than 10 vol%, the discharge amount can be 1 to 60 kJ / m 2 By appropriately adjusting the discharge amount of the corona treatment, there is a tendency for the anchoring force between the adhesive sheet 1 and the optical film to be further improved.

[0160] It should be noted that, as described above, the ratio R1 of the adhesive sheet 1 of the present embodiment obtained by the above test is 2.0 or less. Therefore, even when the surface 1a of the adhesive sheet 1 is subjected to a surface modification treatment, for the adhesive sheet 1, there is a tendency that the ratio of the maximum film thickness to the minimum film thickness is relatively small and is about 2.0 or less.

[0161] From another aspect, the present invention provides an adhesive sheet 1 which is formed from a photocurable composition containing a monomer group and / or a partial polymer of the monomer group,

[0162] wherein at least one of the following (i) and (ii) holds: (i) the photocurable composition contains an ionic compound C having a functional group F capable of reacting with the above monomer group and / or partial polymer; (ii) in the photocurable composition, the partial polymer and the ionic compound C are bonded together via a covalent bond,

[0163] The adhesive sheet 1 has a surface 1a that has been subjected to a surface modification treatment,

[0164] The ratio of the maximum film thickness to the minimum film thickness of the adhesive sheet 1 is 2.0 or less.

[0165] As the numerical ranges of the minimum film thickness, the maximum film thickness, and the ratio of the maximum film thickness to the minimum film thickness of the adhesive sheet 1 having a surface 1a that has been subjected to a surface modification treatment, those described above for the minimum film thickness TL1, the maximum film thickness TH1, and the ratio R1 can be cited respectively.

[0166] (Method for manufacturing an adhesive sheet)

[0167] The adhesive sheet 1 can be manufactured, for example, by the following method. First, as Figure 2A , Figure 2B shown, a first laminate 15 is produced which sequentially includes a base material sheet 21, a coating layer 22 containing a photocurable composition, and a release liner 23. By irradiating the first laminate 15 with light 14, the adhesive sheet 1 can be formed from the coating layer 22 ( Figure 2C ).

[0168] Typically, the irradiation of the first laminate 15 with light 14 can be carried out from one side of the base material sheet 21 ( Figure 2A ). At this time, the light 14 passes through the base material sheet 21 and reaches the coating layer 22, curing the coating layer 22. However, it should be noted that the irradiation of the light 14 can be carried out from one side of the release liner 23, or can be carried out from both sides of the release liner 23 and the base material sheet 21 ( Figure 2B ). The adhesive sheet 1 formed from the coating layer 22 is sandwiched between the base material sheet 21 and the release liner 23 and constitutes a part of the second laminate 16 until the release liner 23 is peeled off.

[0169] Examples of the base material of the release liner 23 (hereinafter, "liner base material") are resin films. Examples of resins that can be contained in the liner base material are polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone, polycarbonate, polyamide, polyimide, polyolefin, (meth)acrylic resins, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.

[0170] The release liner 23 can have light transmissibility of light 14, or can have the same degree of light transmissibility of light 14 as the base material sheet 21.

[0171] The thickness of the release liner 23 is, for example, 10 to 200 μm, and can be 25 to 150 μm.

[0172] The release liner 23 can have layers other than the liner base material. The release liner 23 can have a release layer. The release liner 23, for example, has a liner base material and a release layer formed on one surface of the liner base material. This release liner 23 can be used with the release layer on the coating layer 22 side.

[0173] Typically, the release layer is a cured layer of a release agent composition containing a release agent. As the release agent, various release agents such as silicone-based release agents, fluorine-based release agents, long-chain alkyl-based release agents, fatty acid amide-based release agents, and silica powder can be used. The release liner 23 may include a cured layer of a release agent composition containing a silicone-based release agent as a main component (hereinafter, "silicone release layer"). The silicone release layer is particularly suitable for achieving both adhesion and peelability with respect to the adhesive sheet 1. It should be noted that in this specification, the main component refers to the component with the largest content ratio.

[0174] Examples of silicone-based release agents are various curable silicone materials such as addition reaction type, condensation reaction type, ultraviolet curable type, electron beam curable type, and solvent-free type, and preferably addition reaction curable silicone materials. The addition reaction curable silicone materials are particularly suitable for forming a release layer that achieves both adhesion and peelability with respect to the adhesive sheet 1. The curable silicone material may be a silicone-modified resin obtained by graft polymerization or the like to introduce a reactive silicone into an organic resin such as urethane, epoxy, or alkyd resin.

[0175] Examples of the addition reaction curable silicone material are polyorganosiloxanes having a vinyl group or an alkenyl group in the molecule. The addition reaction curable silicone material may not have a hydrosilyl group. Examples of the alkenyl group are 3-butenyl, 4-pentenyl, 5-hexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl, 9-decenyl, 10-undecenyl, and 11-dodecenyl. Examples of the polyorganosiloxane are polyalkylalkylsiloxanes such as polydimethylsiloxane, polydiethylsiloxane, and polymethylethylsiloxane, polyalkylarylsiloxanes, and copolymers of various Si atom-containing monomers such as poly(dimethylsiloxane-diethylsiloxane). The polyorganosiloxane is preferably polydimethylsiloxane.

[0176] A release agent composition containing a silicone-based release agent as a main component (hereinafter, "silicone release agent composition") usually contains a crosslinking agent. Examples of the crosslinking agent are polyorganosiloxanes having a hydrosilyl group. The crosslinking agent may have two or more hydrosilyl groups in one molecule.

[0177] The silicone release agent composition may also contain a curing catalyst. Examples of the curing catalyst are platinum-based catalysts. Examples of the platinum-based catalysts are chloroplatinic acid, platinum olefin complexes, and olefin complexes of chloroplatinic acid. The amount of the platinum-based catalyst is, for example, 10 to 1000 ppm (weight basis, in terms of platinum) relative to all solid components of the composition.

[0178] The silicone release agent composition may also contain additives. Examples of the additives are release control agents and adhesion improvers. Examples of the release control agents are unreacted silicone resins, and more specific examples are silicone oxides such as octamethylcyclotetrasiloxane and MQ resins. The total amount of the release control agent and the adhesion improver is, for example, 1 to 30% by weight based on all solid components of the composition. Other examples of the additives are fillers, antistatic agents, antioxidants, ultraviolet absorbers, plasticizers, and colorants. The total amount of the other additives is, for example, 10% by weight or less based on all solid components of the composition.

[0179] The silicone release agent composition may also contain an organic solvent. Examples of the organic solvent are hydrocarbon solvents such as cyclohexane, n - hexane, and n - heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; ketone solvents such as acetone and methyl ethyl ketone; and alcohol solvents such as methanol, ethanol, and butanol. Two or more organic solvents may also be contained. The amount of the organic solvent is preferably 80 to 99.9% by weight of the silicone release agent composition.

[0180] The release layer can be formed, for example, by heating and drying a coating film containing the release agent composition formed on a substrate. Coating of the release agent composition can be carried out by various coating methods such as roll coating, roll licking coating, gravure coating, reverse coating, roller brush, spraying, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, die lip coating, and die coating. Heating and drying can be carried out by hot air drying, for example. The heating temperature and time vary depending on the heat resistance of the substrate, and are usually about 80 to 150°C and 10 seconds to 10 minutes. If necessary, irradiation with active energy rays such as ultraviolet rays can also be used in combination.

[0181] The thickness of the release layer is, for example, 10 to 300 nm. The upper limit of the thickness can be 200 nm or less, 150 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, less than 100 nm, 90 nm or less, 80 nm or less, 70 nm or less, less than 70 nm, and further can be 65 nm or less. The lower limit of the thickness can be 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, and further can be 50 nm or more.

[0182] The release liner 23 can be single - sheeted or strip - shaped.

[0183] Examples of the substrate sheet 21 are resin films. Examples of the resin contained in the substrate sheet 21 are the same as those of the resin that can be contained in the substrate.

[0184] Preferably, the substrate sheet 21 has excellent light transmittance to light 14.

[0185] The thickness of the base material sheet 21 is, for example, 10 to 200 μm, and may be 25 to 150 μm.

[0186] The base material sheet 21 may have a release layer on the surface on the side of the coating layer 22. Examples of the release layer that the base material sheet 21 may have and its production method are the same as those of the release layer that the release liner 23 may have and its production method. A release layer may also be provided on both the release liner 23 and the base material sheet 21. In this case, the release layers of both may be formed from a release agent composition containing the same release agent as the main component. In addition, the thicknesses of the release layers of both may be different. For example, the release layer provided on the base material sheet 21 may be thicker.

[0187] The base material sheet 21 can generally be selected as a sheet having a greater peeling force from the adhesive sheet 1 than the release liner 23.

[0188] The base material sheet 21 can be a single sheet or a strip.

[0189] The first laminate 15 can be formed, for example, by forming the coating layer 22 on the base material sheet 21 (or the release liner 23) and disposing the release liner 23 (or the base material sheet 21) on the formed coating layer 22. In addition, the first laminate 15 can be formed by coating in such a manner that the photocurable composition flows into the following space, which is the space between the base material sheet 21 and the release liner 23 that are held at a given interval with their main surfaces facing each other.

[0190] For the formation of the coating layer 22, various coating methods such as roll coating, roll kiss coating, gravure coating, reverse coating, roll brushing, spraying, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, die lip coating, and die coating can be used.

[0191] The thickness of the coating layer 22 can be adjusted according to the target thickness of the adhesive sheet 1. For example, it can be 5 to 500 μm, and can be 5 to 250 μm, 5 to 150 μm, 5 to 100 μm, 5 to 50 μm, 5 to 30 μm, 5 to 25 μm, and further can be 5 to 20 μm.

[0192] The light 14 irradiated onto the first laminate 15 is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light 14 may include light having a wavelength in the same region as the absorption wavelength of the photoinitiator contained in the photocurable composition. The light 14 obtained by blocking short-wavelength light of 300 nm or less through a filter or the like may be irradiated, and blocking the short-wavelength light is suitable for suppressing deterioration of the base material sheet 21 caused by the light 14. The light source of the light 14 is, for example, a light irradiation device equipped with an ultraviolet irradiation lamp. Examples of the ultraviolet irradiation lamp are ultraviolet LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, microwave-excited mercury lamps, black lights, chemical lamps, germicidal lamps, low-pressure discharge mercury lamps, and excimer lasers. Two or more ultraviolet irradiation lamps may also be combined.

[0193] The irradiation of the light 14 may be continuous or intermittent.

[0194] The illuminance of the light 14 is, for example, 1 to 20 mW / cm 2 . The irradiation time of the light 14 is, for example, 5 minutes to 5 hours. The cumulative light amount of the light 14 with respect to the first laminate 15 is, for example, 100 to 5000 mJ / cm 2 .

[0195] It should be noted that, if necessary, the release liner 23 can be peeled off from the second laminate 16 to expose the surface (for example, surface 1a) of the adhesive sheet 1, and a surface modification treatment can be performed on this surface.

[0196] [Embodiments of the optical laminate]

[0197] An example of the optical laminate of this embodiment is shown in Figure 3 . Figure 3 The optical laminate 10 includes the above-mentioned adhesive sheet 1 and at least one optical film 2 selected from a polarizing film and a retardation film. The adhesive sheet 1 is preferably in direct contact with the optical film 2. In Figure 3 the example, the surface 1a of the adhesive sheet 1 is in contact with the optical film 2. The optical laminate 10 may have a structure in which the base material sheet used in manufacturing the adhesive sheet 1 is laminated on the adhesive sheet 1. The optical laminate 10 can be used as an optical film with an adhesive sheet.

[0198] (Optical film)

[0199] The optical film 2 has a surface 2a facing the adhesive sheet 1. For example, the surface 2a is in contact with the surface 1a of the adhesive sheet 1. The surface 2a of the optical film 2 has been subjected to a surface modification treatment. Depending on the surface 2a that has been subjected to the surface modification treatment, there is a tendency to improve the anchoring force between the adhesive sheet 1 and the optical film 2. As the surface modification treatment, the surface modification treatment described above for the adhesive sheet 1 can be cited.

[0200] The surface 2a is preferably subjected to a corona treatment as a surface modification treatment. In the case where the surface 2a is subjected to a corona treatment, conditions such as the discharge amount can be appropriately adjusted, for example, within the range described above for the adhesive sheet 1.

[0201] As described above, the optical film 2 includes at least one selected from a polarizing film and a retardation film. The optical film 2 may be a laminated film including a polarizing film and / or a retardation film. The optical film 2 may include a glass film. However, the optical film 2 is not limited to the above examples.

[0202] The polarizing film includes a polarizer. Typically, the polarizing film includes a polarizer and a protective film (transparent protective film). The protective film is disposed, for example, in contact with the main surface (the surface having the widest area) of the polarizer. The polarizer may be disposed between two protective films. The protective film may be disposed on at least one surface of the polarizer.

[0203] The polarizer is not particularly limited. For example, examples thereof include a polarizer obtained by adsorbing a dichroic substance such as iodine or a dichroic dye onto a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or a partially saponified ethylene-vinyl acetate copolymer film and performing unidirectional stretching; a polyene-oriented film such as a dehydrated product of polyvinyl alcohol or a hydrochloric acid-removed product of polyvinyl chloride. Typically, the polarizer is formed of a polyvinyl alcohol film (the polyvinyl alcohol film includes a partially saponified ethylene-vinyl acetate copolymer film) and a dichroic substance such as iodine.

[0204] The thickness of the polarizer is not particularly limited. For example, it is 80 μm or less, and may be 50 μm or less, 30 μm or less, 25 μm or less, and further may be 20 μm or less. The lower limit of the thickness of the polarizer is not particularly limited. For example, it is 1 μm or more, and may be 5 μm or more, 10 μm or more, and further may be 15 μm or more. The dimensional change of the thin polarizer (for example, the thickness is 20 μm or less) is suppressed, which can contribute to the improvement of the durability of the optical laminate, particularly the durability at high temperatures.

[0205] As a material for the protective film, for example, a thermoplastic resin with excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. can be used. Specific examples of such thermoplastic resins include cellulose resins such as cellulose triacetate, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The material of the protective film can be a thermosetting resin or an ultraviolet curable resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, silicone, etc. When the polarizing film has two protective films, the materials of the two protective films can be the same or different from each other. For example, a protective film formed of a thermoplastic resin can be adhered to one main surface of the polarizer via an adhesive, and a protective film formed of a thermosetting resin or an ultraviolet curable resin can be adhered to the other main surface of the polarizer. The protective film can contain one or more arbitrary additives. As additives, for example, the following can be cited: ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants, etc.

[0206] The thickness of the protective film can be appropriately determined. Generally, from the aspects of strength, processability and other operability, film properties, etc., it is about 10 to 200 μm.

[0207] The polarizer and the protective film are usually bonded together via an aqueous adhesive or the like. As the aqueous adhesive, isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latexes, aqueous polyurethanes, aqueous polyesters, etc. can be exemplified. As other adhesives other than the above adhesives, ultraviolet curable adhesives, electron beam curable adhesives, etc. can be cited. The electron beam curable adhesive for polarizing films shows appropriate adhesiveness to various protective films. The adhesive can also contain a metal compound filler.

[0208] In the polarizing film, a retardation film or the like can also be formed on the polarizer instead of the protective film. Additionally, another protective film, a retardation film, etc. can be provided on the protective film.

[0209] Regarding the protective film, a hard coat can also be provided on the surface opposite to the surface bonded to the polarizer, and it can also be subjected to treatments for the purposes of antireflection, anti-adhesion, diffusion, antiglare, etc.

[0210] The polarizing film can be a circularly polarizing film.

[0211] As the retardation film, a film obtained by stretching a polymer film, a film obtained by orienting and immobilizing a liquid crystal material can be used. The retardation film has birefringence in the in-plane and / or thickness direction, for example.

[0212] The retardation film includes a retardation film for antireflection (refer to Japanese Unexamined Patent Application Publication No. 2012-133303

[0221] ,

[0222] ,

[0228] ), a retardation film for viewing angle compensation (refer to Japanese Unexamined Patent Application Publication No. 2012-133303

[0225] ,

[0226] ), an in-plane switching retardation film for viewing angle compensation (refer to Japanese Unexamined Patent Application Publication No. 2012-133303

[0227] ), and the like.

[0213] The specific configuration of the retardation film, such as the retardation value, the arrangement angle, the three-dimensional birefringence, whether it is a single layer or a multilayer, etc., is not particularly limited, and a known retardation film can be used.

[0214] The thickness of the retardation film is preferably 20 μm or less, more preferably 10 μm or less, further preferably 1 - 9 μm, and particularly preferably 3 - 8 μm.

[0215] The retardation film can include, for example, a quarter-wave plate and / or a half-wave plate obtained by orienting and immobilizing a liquid crystal material.

[0216] In the present embodiment, there is a tendency for the anchoring force between the adhesive sheet 1 and the optical film 2 to be large. The anchoring force is, for example, 5.0 N / 25 mm or more, and can also be 8.0 N / 25 mm or more, 9.0 N / 25 mm or more, 10.0 N / 25 mm or more, 11.0 N / 25 mm or more, 12.0 N / 25 mm or more, 13.0 N / 25 mm or more, 14.0 N / 25 mm or more, 15.0 N / 25 mm or more, 16.0 N / 25 mm or more, 17.0 N / 25 mm or more, 18.0 N / 25 mm or more, 19.0 N / 25 mm or more, and further can be 20.0 N / 25 mm or more. The larger the anchoring force, the more effectively the peeling between the adhesive sheet 1 and the optical film 2 can be suppressed. The upper limit of the anchoring force is not particularly limited, and is, for example, 50 N / 25 mm or less, and can also be 30 N / 25 mm or less.

[0217] The anchoring force between the adhesive sheet 1 and the optical film 2 can be measured by the following method. First, a test piece is prepared by cutting out an optical laminate 10 to be evaluated with a width of 25 mm and a length of 150 mm. Next, the entire surface of the optical film 2 included in the test piece is laminated with a stainless-steel test plate via a double-sided tape, and a 2-kg roller is reciprocated once to press them together. Next, the adhesive sheet 1 included in the test piece is laminated with an evaluation sheet, and a 2-kg roller is reciprocated once to press them together. The evaluation sheet has a size of 30 mm in width and 150 mm in length, and is not particularly limited as long as it does not peel off from the adhesive sheet 1 during the test. As the evaluation sheet, for example, an ITO film (such as 125 Tetoraito OES (manufactured by Oike Industry Co., Ltd.)) can be used. Next, using a commercially available tensile testing machine, while holding the evaluation sheet, the adhesive sheet 1 is peeled off from the optical film 2 at a peeling angle of 180° and a tensile speed of 300 mm / min, and the average value of the peeling force at this time is determined as the anchoring force between the adhesive sheet 1 and the optical film 2. It should be noted that the above test is performed in an atmosphere of 23°C.

[0218] Another example of the optical laminate of the present embodiment is shown in Figure 4 . Figure 4 The optical laminate 11 has a laminated structure in which an adhesive sheet 1A, an optical film 2A, an adhesive sheet 1B, and an optical film 2B are laminated in this order. The optical laminate 11 may have a structure in which a base material sheet used when manufacturing the adhesive sheet 1A is laminated on the adhesive sheet 1A.

[0219] In the optical laminate 11, typically, the optical film 2A is a retardation film, and the optical film 2B is a polarizing film. The adhesive sheet 1B functions as an interlayer adhesive for the optical films 2A and 2B. The adhesive sheet 1B may be an adhesive sheet using a known adhesive.

[0220] The optical laminate of the present embodiment can be circulated and stored, for example, in the form of a wound body obtained by winding a strip-shaped optical laminate or in the form of a single-sheet optical laminate.

[0221] [Embodiments of Image Display Devices]

[0222] The image display device of the present embodiment includes, for example, the above-described optical laminate 10 or 11. The image display device can be formed, for example, by bonding the optical laminate 10 or 11 to an image display panel. The bonding is performed, for example, by the adhesive sheet 1. The image display device can be an organic EL display or a liquid crystal display. However, the image display device is not limited to the above examples. The image display device can also be an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED: Field Emission Display), etc. The image display device can be used for home appliance applications, in-vehicle applications, public information display (PID) applications, etc.

[0223] Example

[0224] Hereinafter, the present invention will be described in more detail by way of examples. The present invention is not limited to the examples shown below.

[0225] [Monomer slurry A1]

[0226] 99 parts by weight of 2-methoxyethyl acrylate (MEA), 1 part by weight of 4-hydroxybutyl acrylate (HBA), 0.05 part by weight of 1-hydroxycyclohexyl-phenyl ketone (Omnirad 184, manufactured by IGM Resins B.V.) and 0.05 part by weight of 2,2-dimethoxy-1,2-diphenylethane-1-one (Omnirad 651, manufactured by IGM Resins B.V.) as a photopolymerization initiator were put into a four-necked flask, and ultraviolet rays were irradiated in a nitrogen atmosphere, whereby a monomer slurry A1 partially photopolymerized was obtained. The irradiation of ultraviolet rays was carried out until the viscosity of the liquid in the flask (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30 ° C) reached about 20 Pa·s.

[0227] [Monomer slurries A2 to A7]

[0228] The monomers used were changed as shown in Table 1, and monomer slurries A2 to A7 were prepared by the same method as monomer slurry A1 except for this. It should be noted that in monomer slurry A3, (2-acryloyloxyethyl) trimethylammonium = bis(trifluoromethanesulfonyl) imide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.: CASRN. 827027-31-6) as the ionic compound C was reacted with the monomer group, thereby forming a partial polymer having a structural unit derived from the ionic compound C in the main chain.

[0229] [Table 1]

[0230]

[0231] The abbreviations in Table 1 are as follows.

[0232] BA: n-Butyl acrylate

[0233] MEA: 2-Methoxyethyl acrylate

[0234] CBA: Ethyl carbitol acrylate

[0235] HBA: 4-Hydroxybutyl acrylate

[0236] Ionic compound 1: (2-Acryloyloxyethyl)trimethylammonium bis(trifluoromethanesulfonyl)imide (manufactured by Fujifilm Wako Pure Chemical Corporation: CAS RN. 827027-31-6)

[0237] Omnirad184: 1-Hydroxycyclohexyl phenyl ketone (manufactured by Omnirad184, IGM Resins B.V.)

[0238] Omnirad651: 2,2-Dimethoxy-1,2-diphenylethan-1-one (manufactured by Omnirad651, IGM Resins B.V.)

[0239] [Photocurable compositions C1 to C15]

[0240] Next, a monomer slurry, a crosslinking agent, a conductive agent (ionic compound), etc. were mixed so as to have the composition shown in Table 2 below, and photocurable compositions C1 to C15 were obtained. It should be noted that in photocurable composition C15, methoxypolyethylene glycol acrylate (Osaka Organic Chemical Industry Co., Ltd., MPE400A) was further added as a monomer component.

[0241] [Table 2]

[0242]

[0243] The abbreviations in Table 2 are as follows.

[0244] MPE400A: Methoxypolyethylene glycol acrylate (Osaka Organic Chemical Industry Co., Ltd., MPE400A)

[0245] NDDA: 1,9-Nonanediol diacrylate

[0246] AS110: 1-Ethyl-3-methylimidazole Bis(fluorosulfonyl)imide (Elexcel AS-110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)

[0247] Ionic compound 1: (2-acryloyloxyethyl) trimethylammonium = bis(trifluoromethanesulfonyl) imide (manufactured by Fujifilm Wako Pure Chemical Corporation: CAS RN. 827027-31-6)

[0248] A-100: Acetoacetoxysilane coupling agent (A-100, manufactured by Soken Chemical & Engineering Co., Ltd.)

[0249] (Comparative Example 1)

[0250] [Release liner A]

[0251] 30 parts by weight of an addition reaction curable silicone (LTC761 containing hexenyl polyorganosiloxane, 30 wt% toluene solution, manufactured by Toray Dow Corning), 0.9 parts by weight of a release control agent (BY24-850 containing unreactive silicone resin, manufactured by Toray Dow Corning), 2 parts by weight of a curing catalyst (SRX212 containing a platinum catalyst, manufactured by Toray Dow Corning), and a toluene / hexane mixed solvent (volume ratio 1:1) as a diluting solvent were mixed to obtain a silicone-based release agent composition. The concentration of the silicone solid component in the release agent composition was 1.0 wt%. Next, the release agent composition was coated on one side of a liner substrate (Lumirror XD500P as a polyester film, thickness 75 μm) using a wire bar and heated at 130°C for 1 minute to produce Release liner A having a release layer (thickness 60 nm) on one side.

[0252] [Release liner B]

[0253] The thickness of the release agent composition coated on the liner substrate was changed, and except for this, Release liner B having a release layer (thickness 120 nm) on one side was produced by the same method as Release liner A.

[0254] [Adhesive sheet]

[0255] The photocurable composition C1 was coated on the surface of the release layer of Release liner A using an applicator to form a coated layer. The thickness of the coated layer was adjusted so that the thickness of the adhesive sheet reached 25 μm. Next, the above-mentioned Release liner B was placed on the formed coated layer to obtain a first laminate. Release liner B was placed so that the release layer was in contact with the coated layer. Next, ultraviolet rays (Black light source) were irradiated from the side of Release liner A in the first laminate under the conditions of an illuminance of 2.5 mW / cm 2 , irradiation time of 960 seconds to photocure the coated layer. Thus, the adhesive sheet of Comparative Example 1 sandwiched between Release liner A and Release liner B was obtained. In other words, a second laminate composed of Release liner A, the adhesive sheet, and Release liner B was obtained.

[0256] (Comparative Example 2 and Examples 1 to 13)

[0257] The photocurable composition used was changed as shown in Table 3, and except for this, Comparative Example 2 and adhesive sheets of Examples 1 to 13 sandwiched between release liner A and release liner B were obtained by the same method as in Comparative Example 1.

[0258] [Maximum film thickness and minimum film thickness]

[0259] From the second laminate produced in the examples and comparative examples, release liner B was peeled off to expose the surface of the adhesive sheet. Next, using a precision thickness gauge, the distances between two mutually opposite surfaces of the adhesive sheet were measured along the width direction of the adhesive sheet. For the measured distances between the two surfaces, the maximum value was regarded as the maximum film thickness TH2 of the adhesive sheet, and the minimum value was regarded as the minimum film thickness TL2 of the adhesive sheet. Based on this result, for the adhesive sheet before corona treatment, the ratio R2 of the maximum film thickness TH2 to the minimum film thickness TL2 was determined.

[0260] Next, at a discharge amount of 3.8 kJ / m 2 The exposed surface of the adhesive sheet was subjected to corona treatment. The corona treatment was carried out by transporting the adhesive sheet along the length direction of the adhesive sheet and passing it through a treatment device for corona treatment. Next, using a precision thickness gauge, the distances between two mutually opposite surfaces of the adhesive sheet were measured along the width direction of the adhesive sheet. It should be noted that in the adhesive sheets of Comparative Examples 1 and 2, due to the above-mentioned corona treatment, striped thickness unevenness (for example, Figure 5 ) occurred along the moving direction of the adhesive sheet in the treatment device. Figure 5 The surface of the adhesive sheet of Comparative Example 1 pasted to the substrate by a tape is shown. In Comparative Examples 1 and 2, the distances between two mutually opposite surfaces were measured in a manner that cut across this thickness unevenness.

[0261] For the measured distances between the two surfaces, the maximum value was regarded as the maximum film thickness TH1 of the adhesive sheet, and the minimum value was regarded as the minimum film thickness TL1 of the adhesive sheet. Based on this result, the ratio R1 of the maximum film thickness TH1 to the minimum film thickness TL1 was determined.

[0262] [Anchoring force]

[0263] First, a polarizing film was produced by the following method. A polyvinyl alcohol film with a thickness of 80 μm was dyed in an iodine solution with a temperature of 30 °C and a concentration of 0.3% for 1 minute while being stretched 3 times between rollers with different speed ratios. Next, while being immersed in an aqueous solution with a temperature of 60 °C containing 4% boric acid and 10% potassium iodide by concentration for 0.5 minutes, it was stretched until the total stretching ratio reached 6 times. Next, after being immersed in an aqueous solution with a temperature of 30 °C containing 1.5% potassium iodide by concentration for 10 seconds for cleaning, it was dried at 50 °C for 4 minutes, thereby obtaining a polarizer with a thickness of 28 μm. Using a polyvinyl alcohol-based adhesive, a transparent protective film with a thickness of 30 μm formed of a modified acrylic polymer having a lactone ring structure was adhered to one side of the polarizer. Further, using a polyvinyl alcohol-based adhesive, a transparent protective film with a thickness of 47 μm having a hard coat (HC) formed on a triacetyl cellulose film (manufactured by Konica Minolta, trade name "KC4UY") was adhered to the other side of the polarizer. Heat drying was performed in an oven set at 70 °C for 5 minutes, thereby producing a polarizing film. Further, the surface of the polarizing film on the side of the transparent protective film formed of the modified acrylic polymer was corona-treated at a discharge amount of 63 W / m 2 ·min.

[0264] Next, an optical laminate was produced by disposing the above polarizing film on the exposed surface of the above adhesive sheet after the corona treatment for determining the ratio R1. However, it should be noted that in Comparative Examples 1 and 2, due to the striped thickness unevenness generated in the adhesive sheet, the adhesive sheet could not be adhered to the polarizing film, and an optical laminate could not be produced. It should be noted that the polarizing film was disposed in such a manner that the surface on the side of the transparent protective film formed of the modified acrylic polymer was in contact with the adhesive sheet.

[0265] For the produced optical laminate, the anchoring force between the adhesive sheet and the polarizing film was measured by the above method. As the double-sided tape, "No. 531" manufactured by Nitto Denko Corporation was used. As the stainless steel test plate, a plate of SUS304 (width 40 mm × length 120 mm) was used. As the evaluation sheet, an ITO film (125TetoraitoOES, manufactured by Oike Industry Co., Ltd.) was used. As the tensile testing machine, Autograph SHIMAZU AG-I 10KN (manufactured by Shimadzu Corporation) was used.

[0266] [Surface resistance value]

[0267] The second laminate produced in the examples and comparative examples was peeled off the release liner B to expose the surface of the adhesive sheet, and the surface resistivity of the adhesive sheet was measured. Using a resistivity meter (Hiresta-UP MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd.), the surface resistivity was measured based on the method specified in JIS K6911:1995. The measurement conditions were: applied voltage of 100 V and applied time of 10 seconds.

[0268] [Storage modulus and glass transition temperature]

[0269] The dynamic viscoelasticity of the adhesive sheets produced in the examples and comparative examples was measured by the above method, and the storage modulus G' and the glass transition temperature (Tg) at 25 °C were determined.

[0270]

[0271] As can be seen from Table 3, for the adhesive sheets of the examples where the above-mentioned requirement (i) or (ii) is satisfied and the ratio R1 of the maximum film thickness TH1 to the minimum film thickness TL1 after corona treatment is 2.0 or less, the surface resistivity is 1.0×10 13 Ω / □ or less, which is low enough. In addition, for the adhesive sheets of the examples, by performing corona treatment, the anchoring force to the polarizing film was adjusted to a large value of 5.0 N / 25 mm or more.

[0272] As described above, for the adhesive sheets of the comparative examples, striped thickness unevenness occurred due to corona treatment. It is speculated that the generation of this thickness unevenness is caused by the segregation of the conductive agent in the adhesive sheet during corona treatment. As described above, the adhesive sheets of the comparative examples could not be bonded to the polarizing film due to the thickness unevenness.

[0273] Industrial applicability

[0274] The adhesive sheet of the present invention can be used, for example, in an optical laminate and an image display device.

Claims

1. An adhesive sheet formed from a photocurable composition containing a monomer group and / or a partial polymer of the monomer group, Among them, at least one of the following (i) and (ii) holds: (i) The photocurable composition contains an ionic compound having a functional group capable of reacting with the monomer group and / or the partial polymer; (ii) In the photocurable composition, the partial polymer and the ionic compound are bonded together via a covalent bond, and the ratio R1 determined by the following test is 2.0 or less, Test: At a discharge amount of 3.8 kJ / m 2 Corona-treat one surface of the adhesive sheet, determine the maximum film thickness TH1 and the minimum film thickness TL1 of the adhesive sheet after the corona treatment, and determine the ratio R1 of the maximum film thickness TH1 to the minimum film thickness TL1.

2. The adhesive sheet according to claim 1, wherein the ratio R1 is 1.3 or less.

3. The adhesive sheet according to claim 1, wherein the minimum film thickness TL1 is 10 μm or more.

4. The adhesive sheet according to claim 1, wherein the ratio R2 of the maximum film thickness TH2 to the minimum film thickness TL2 of the adhesive sheet before the test is 1.5 or less.

5. The adhesive sheet according to claim 1, wherein the functional group is at least one selected from (meth)acryloyloxy, (meth)acrylamino, vinyl, allyl, styryl, hydroxyl, amino, mercapto, and epoxy groups.

6. The adhesive sheet according to claim 1, wherein the ionic compound has an anion and a cation, and among the anion and the cation, only the cation has the functional group.

7. The adhesive sheet according to claim 1, wherein the monomer group contains an ether group-containing monomer.

8. The adhesive sheet according to claim 1, wherein the photocurable composition does not contain an isocyanate crosslinking agent.

9. The adhesive sheet according to claim 1, wherein in the photocurable composition, the blending amount of the ionic compound is 0.1 part by weight or more based on the total 100 parts by weight of the monomer group and the partial polymer.

10. The adhesive sheet according to claim 1, wherein the content rate of the solvent in the photocurable composition is 5% by weight or less.

11. The adhesive sheet according to claim 1, which has a surface subjected to a surface modification treatment.

12. The adhesive sheet according to claim 1 has a surface resistance value of 1.0×10 13 Ω / square or less.

13. The adhesive sheet according to claim 1, having a glass transition temperature of -60°C to 25°C.

14. The adhesive sheet according to claim 1, having a storage modulus G' at 25 °C of 1.0×10 3 Pa to 1.0×10 6 Pa.

15. An adhesive sheet formed from a photocurable composition containing a monomer group and / or a partial polymer of the monomer group, Among them, at least one of the following (i) and (ii) holds: (i) The photocurable composition contains an ionic compound having a functional group capable of reacting with the monomer group and / or the partial polymer; (ii) In the photocurable composition, the partial polymer and the ionic compound are bonded together via a covalent bond, the adhesive sheet has a surface subjected to a surface modification treatment, and the ratio of the maximum film thickness to the minimum film thickness of the adhesive sheet is 2.0 or less.

16. An optical laminate comprising: the adhesive sheet according to any one of claims 1 to 15, and an optical film containing at least one selected from a polarizing film and a retardation film.

17. The optical laminate according to claim 16, wherein The anchoring force between the adhesive sheet and the optical film is 10.0 N / 25 mm or more.

18. An image display device including the optical laminate according to claim 16.

Images