Adhesive tape

Abstract

An object of the present invention is to provide an adhesive tape having excellent high-load holding force, re-peelability over time, and storage stability in terms of adhesive force. The present invention is an adhesive tape comprising a substrate layer and an adhesive layer; the substrate layer has a breaking stress of 1 to 100 MPa and an elongation at break of 400 to 3000%, and the adhesive layer contains a tackifying resin and a triblock copolymer having repeating units represented by the general formula (1): In the above general formula (1), A, B, and C each independently represent a repeating unit, A and C each independently represent a methacrylic acid alkyl ester monomer unit, B represents an acrylic acid alkyl ester monomer unit, p, q, and r each independently represent the degree of polymerization of each monomer unit; A and C may be the same or may be methacrylic acid alkyl ester monomer units having different chemical structures. In the above general formula (1), * is a bonding position indicating bonding to other atoms.

Description

Technical Field

[0001] The present invention relates to an adhesive tape. Background Art

[0002] Adhesive tapes have excellent workability and high bonding reliability. Therefore, adhesive tapes are widely used as a bonding means to fix components of relatively large electronic devices such as thin-film televisions, home appliances, and office automation equipment, or to fix components of relatively small electronic devices such as portable electronic terminals, cameras, and personal computers. More specifically, in various industrial fields such as office automation equipment, IT and home appliances, and automobiles, adhesive tapes are not only used for fixing metal plates constituting large electronic devices or fixing exterior components to housings, fixing exterior components or rigid components such as batteries to small electronic devices, and temporarily fixing the components, but are also used for labeling purposes such as displaying product information.

[0003] In recent years, from the perspective of protecting the global environment and for the purpose of saving resources, there is an increasing trend in the above-mentioned industrial fields to reuse or re-use the reusable or reusable parts used in the products by disassembling the products after use. At this time, when using an adhesive tape, it is necessary to peel off the adhesive tape attached to the parts, but the adhesive tape generally has a strong adhesive force and is attached to multiple parts of the product, so the operation of peeling them off requires a considerable amount of labor. Therefore, an adhesive tape that can be relatively easily peeled off and removed when reused or re-used is needed.

[0004] As a technology related to an adhesive tape that can be easily peeled and removed, for example, Patent Document 1 can be cited. Patent Document 1 discloses an adhesive tape, which has an adhesive portion and a handle portion, and can be peeled off from the adherends on both sides of the adhesive portion by clamping the handle portion and stretching the adhesive tape in a direction roughly parallel to the adhesive surface. However, in small electronic devices, since the space between the components in the electronic device is narrow, there is a problem that it is difficult to stretch and peel the adhesive tape attached to the space in a direction parallel to the adhesive surface. As a technology to solve this problem, Patent Document 2 discloses an adhesive tape that can be removed again by stretching it in a direction of 30° relative to the adhesive surface.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-124289

[0008] Patent Document 2: Japanese Patent Application Publication No. 2016-26255 Summary of the invention

[0009] The technical problem to be solved by the present invention

[0010] In the patent document 1, after the adhesive tape was cured in an oven at 40 °C for 30 minutes, the "holding power of the adhesive tape" for suspending a 1 kg heavy object was evaluated. In addition, in the patent document 2, research was conducted on stretching and removing an adhesive article without breaking and leaving no adhesive residue. However, in the technologies of the patent documents 1 and 2, the "high load holding power" for maintaining the adhesive force under a higher applied load was not studied. In addition, when an adhesive tape or an adhesive article is attached to an adherend and a certain period of time has passed, the degree of adhesion to the adherend is further improved, resulting in the problem that the re-peelability from the adherend becomes difficult. However, for such "peelability over time", it was not studied at all in the technologies of the patent documents 1 and 2. In addition, the adhesive tapes such as the manufactured adhesive tapes or adhesive articles can be stored in various environments before starting to be used. At this time, depending on the storage environment (for example, under high temperature and high humidity), there is sometimes a problem that the adhesive force of the adhesive tape decreases before starting to be used, and there is also a need for "storage stability of the adhesive force" that can maintain the initial performance during the period before starting to use the adhesive tape.

[0011] Therefore, an object of the present invention is to provide an adhesive tape (for example, a pressure-sensitive adhesive tape) having excellent high load holding power, peelability over time, and storage stability in terms of adhesive force.

[0012] Means for solving the technical problem

[0013] In view of the above technical problems, the present inventors conducted in-depth research and found that by using an adhesive layer (for example, a pressure-sensitive adhesive layer) containing a triblock copolymer having a specific chemical structure and a substrate layer having a specific tensile strength and elongation at break, the above technical problems were solved, and thus the present invention was completed.

[0014] That is, the present invention is as follows.

[0015] [1] The present invention is an adhesive tape comprising a substrate layer and an adhesive layer,

[0016] The breaking stress of the substrate layer is 1 to 100 MPa, and the elongation at break is 300 to 3000%,

[0017] The adhesive layer contains a tackifying resin (Japanese: adhesion-imparting resin) and a triblock copolymer having repeating units represented by the general formula (1):

[0018] [Chemical formula 1]

[0019]

[0020] (In the above general formula (1), A, B, and C each independently represent a repeating unit. A and C each independently represent an alkyl methacrylate monomer unit, B represents an alkyl acrylate monomer unit, and p, q, and r each independently represent the degree of polymerization of each monomer unit. A and C may be the same or may be alkyl methacrylate monomer units having different chemical structures. In the above general formula (1), * represents the bond position of the bond with other atoms.).

[0021] [2] In the present invention, it is preferred that the weight-average molecular weight Mw of the triblock copolymer is 50,000 to 300,000 and the number-average molecular weight Mn is 50,000 to 300,000.

[0022] [3] In the present invention, it is preferred that the softening point of the tackifying resin is 95 °C or higher.

[0023] [4] In the present invention, it is preferred that the temperature of the softening point of the tackifying resin [°C] × the addition amount of the tackifying resin (the addition amount of the tackifying resin when the triblock copolymer is 100 parts by mass) is 1300 to 13000.

[0024] [5] In the present invention, it is preferred that the base material layer contains a vinyl aromatic block copolymer.

[0025] [6] In the present invention, it is preferred that the peel adhesion is 5 N / 20 mm or more.

[0026] [7] In the present invention, it is preferred that the shear adhesion is 1.0 MPa or more.

[0027] [8] In the present invention, it is preferred that the adhesive layer contains 10 to 150 parts by mass of the tackifying resin with respect to 100 parts by mass of the triblock copolymer.

[0028] [9] In the present invention, it is preferred that the adhesive layer contains a filler.

[0029] Effects of the Invention

[0030] The adhesive force of the adhesive tape provided by the present invention exhibits excellent high-load holding force, re-peelability over time, and storage stability. Detailed Embodiments

[0031] Hereinafter, the embodiments of the present invention (hereinafter referred to as "the present embodiments") will be described in detail, but the present invention is not limited to the present embodiments.

[0032] The adhesive tape of the present embodiment is an adhesive tape having a base material layer and an adhesive layer. In addition, the breaking stress of the base material layer is 1 to 100 MPa. And the elongation at break of the base material layer is 300 to 3000%. Further, the adhesive layer contains a tackifying resin (for example, a resin capable of imparting pressure-sensitive adhesiveness) and a triblock copolymer having repeating units represented by the general formula (1),

[0033] [Chemical formula 2]

[0034]

[0035] (In the above general formula (1), A, B, and C each independently represent a repeating unit, A and C each independently represent a methacrylic acid alkyl ester monomer unit, B represents an acrylic acid alkyl ester monomer unit, p, q, and r each independently represent the degree of polymerization of each monomer unit; A and C may be the same or may be methacrylic acid alkyl ester monomer units having different chemical structures. In the above general formula (1), * is the bond position indicating the bond with other atoms.).

[0036] By having such a configuration, the adhesive tape of the present embodiment can ensure that the adhesive force exhibits excellent high-load holding force, re-peelability over time, and storage stability.

[0037] Specifically, the base material layer of the adhesive tape of the present embodiment has a breaking stress of 1 to 100 MPa and an elongation at break of 300 to 3000%, enabling the operator to stretch with a light force at the initial stage of peeling the adhesive tape from the adherend (the initial stage of elongation of the adhesive tape); in addition, even if the operator stretches at a relatively fast speed through the peeling operation, the adhesive tape can be peeled from the adherend without breaking (re-peelability can be obtained).

[0038] In addition, since the adhesive layer of the adhesive tape of the present embodiment must contain a tackifying resin and the triblock copolymer represented by the general formula (1), the elastic modulus is very high, and for this reason, it can ensure that the adhesive force exhibits excellent high-load holding force, re-peelability over time, and storage stability.

[0039] It should be noted that the adhesive tape of the present invention has an adhesive layer in contact with the base material layer on at least one surface of the base material layer. In addition, the adhesive tape of the present invention may have two adhesive layers in contact with the base material layer on both surfaces of the base material layer as needed. In this case, the two adhesive layers may be the same as each other or may be different from each other. It should be noted that the adhesive tape of the present invention is not only a general term for an adhesive tape in which an adhesive layer is provided on one or both sides of the base material layer and wound into a roll, but also includes a plate-shaped adhesive tape having an adhesive layer provided on one or both sides of the base material and having a release liner attached thereto.

[0040] Hereinafter, the base material layer and the adhesive layer constituting the adhesive tape of the present invention will be described in detail.

[0041] In the present embodiment, the adhesive tape includes at least one adhesive layer and a base material layer in contact with the adhesive layer. Moreover, the breaking stress of the base material layer is 1 to 100 MPa, and the elongation at break is 400 to 3000%.

[0042] In the present embodiment, the base material layer is not particularly limited as long as it has the above characteristics, and can be appropriately selected from known materials usable for adhesive tapes. It preferably contains the following base material materials for the base material, and may further contain other components as needed.

[0043] The base material layer may have a single-layer structure, or a multi-layer structure of two layers, three layers, or more. In the present embodiment, the breaking stress of the base material layer is 1 to 100 MPa, preferably 10 to 90 MPa, more preferably 15 to 90 MPa, further preferably 30 to 90 MPa, and still more preferably 50 to 90 MPa. By making the breaking stress 1 MPa or more, when peeling the adhesive tape from the adherend, even if the operator stretches it, the adhesive tape can be peeled from the adherend without breaking. In addition, by making the breaking stress 100 MPa or less, it is possible to avoid excessive stress when the operator stretches the adhesive tape.

[0044] The breaking stress of the base material layer means: The base material layer is punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and under the conditions of a measurement atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched in the longitudinal direction at a tensile speed of 500 mm / min, and the stress value measured when fracture occurs.

[0045] In addition, the breaking stress can be adjusted by selecting appropriate materials and applying stretching or other methods in the manufacturing process of the base material layer.

[0046] In the present embodiment, the elongation at break of the base material layer is 300 to 3000%, preferably 500 to 2500%, more preferably 530 to 1700%, further preferably 560 to 1300%, and still more preferably 600 to 1200%. By making the elongation at break 400% or more, even when the adhesive tape is firmly adhered to the adherend, the stress during peeling of the adhesive tape will not become excessive. In addition, by making the elongation at break 3000% or less, the stretching distance will not become too long during peeling of the adhesive tape, and the operation can be carried out in a small space.

[0047] The elongation at break of the base material layer means that the base material layer is blanked into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and under the conditions of a measurement atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched along the length direction at a tensile speed of 500 mm / minute, and the tensile elongation measured when fracture occurs.

[0048] In addition, the elongation at break can be adjusted by selecting appropriate materials and applying stretching or other methods during the manufacturing process of the base material layer.

[0049] In this embodiment, the 50% modulus of the base material layer is preferably 0.1 to 5 MPa, more preferably 0.5 to 4.5 MPa, and further preferably 1 to 4 MPa. By making the 50% modulus 0.1 MPa or more, when a load is applied to the adhesive tape and the adherend, it is possible to suppress defects that occur along with shape deformations such as offsets. In addition, by making the 50% modulus 5 MPa or less, at the initial stage of peeling the adhesive tape from the adherend, the operator can stretch it with a relatively light force.

[0050] The 50% modulus of the base material layer means that the base material layer is blanked into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and under the conditions of a measurement atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched along the length direction at a tensile speed of 500 mm / minute, and the stress value measured when the elongation is 50%.

[0051] In addition, the 50% modulus can be adjusted by selecting appropriate materials and applying stretching or other methods during the manufacturing process of the base material layer.

[0052] In this embodiment, the rubber hardness of the base material layer is preferably 25 to 90 A, more preferably 30 to 85 A, and further preferably 35 to 80 A. By making the rubber hardness 25 A or more, it is possible to prevent the adhesive tape from cracking when stretching and peeling the adhesive tape. In addition, by making the rubber hardness 90 A or less, the base material layer can be softened. For example, when the adherend with the adhesive tape attached falls, the adhesive tape can easily absorb the impact and protect the adherend from the impact (it can improve the impact resistance of the adhesive tape).

[0053] The rubber hardness of the base material layer is the Shore A hardness, which means the value measured using a hardness tester (spring-type rubber hardness tester) (model: GS-719G, manufactured by TECLOCK Co., Ltd.) in accordance with JIS K 6253.

[0054] In addition, the rubber hardness can be adjusted by methods such as selecting appropriate materials, for example, changing the molecular weight of the resin or changing the monomer unit in the case of containing styrene monomer units.

[0055] The average thickness of the base material layer is 10 to 500 μm, preferably 30 to 250 μm, and more preferably 50 to 200 μm. By making the thickness 10 μm or more, the strength of the adhesive tape can be ensured; in addition, by making the thickness 500 μm or less, it is possible to avoid the difficulty of stretching the adhesive tape due to excessive thickness.

[0056] It should be noted that in this specification, the "thickness of the base material layer" refers to the average value obtained by measuring the thickness of any 5 points in the base material layer using a TH-104 paper / membrane thickness measuring machine (manufactured by TESTER SANGYO Co., Ltd.) and averaging these measured values.

[0057] As the ratio of the thickness of the adhesive layer to the thickness of the base material layer, there is no particular limitation, and it can be appropriately selected according to the purpose. The ratio of the thickness of the adhesive layer to the thickness of the base material layer, expressed as [thickness of the adhesive layer / thickness of the base material layer], is preferably 1 / 6 to 6 / 1, more preferably 1 / 3 to 3 / 1, and further preferably 1 / 2 to 2 / 1. If the ratio of the thickness of the adhesive layer to the thickness of the base material layer is within the preferred range, excellent adhesiveness and re-peelability (easy peelability) of the adhesive tape can be obtained. On the other hand, if the ratio is greater than 6 / 1, there is a possibility that only the adhesive layer remains on the adherend in the re-peeling process of the adhesive tape. In addition, if the ratio is less than 1 / 6, when the surface of the adherend is uneven or the like, there is a possibility that the adhesive layer cannot follow the surface, resulting in a decrease in adhesive strength.

[0058] As the material of the base material layer, there is no particular limitation as long as a base material layer having the above specific physical properties can be obtained, and a vinyl aromatic block copolymer is preferably used. As the material of the base material layer, if the vinyl aromatic block copolymer is the main component (a component having a content exceeding 50% by mass in all the materials of the base material layer), the compatibility with the triblock copolymer contained in the adhesive layer is improved, and the adhesion force between the adhesive layer and the base material layer is further improved. Specifically, relative to the total amount of the base material layer, the vinyl aromatic block copolymer preferably contains 5 to 50% by mass, preferably contains 5 to 40% by mass, and preferably contains 10 to 30% by mass.

[0059] Examples of the material for the base material layer include styrene-based resins such as styrene-isoprene copolymer, styrene-isoprene-styrene copolymer, styrene-isoprene-butadiene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene-butene copolymer, and styrene-ethylene-propylene copolymer; polyurethane resins such as ester-based polyurethane and ether-based polyurethane; polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polystyrene; polycarbonate; polymethylpentene; polysulfone; polyetheretherketone; polyethersulfone; polyetherimide; polyimide film; fluororesin; nylon; acrylic resins, etc. They can be used alone or in combination of two or more; preferably, two or more are used in combination.

[0060] Among them, styrene-based resins or polyurethane resins are preferred because they can easily obtain appropriate breaking stress and elongation at break. More preferably, styrene-based resins are used, and it is particularly preferred to use a combination of styrene-isoprene copolymer and styrene-isoprene-styrene copolymer.

[0061] Examples of the vinyl aromatic block copolymer include styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, styrene-isoprene-butadiene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-ethylene-butene block copolymer, styrene-ethylene-propylene block copolymer, and their hydrogenated types, etc. The hydrogenated type of styrene-isoprene-butadiene-styrene block copolymer is particularly preferred.

[0062] The styrene-based resin is a resin showing thermoplasticity, so it has excellent formability such as extrusion molding and injection molding, and is easily formed into a base material layer. In addition, the styrene-based resin can easily obtain particularly excellent elongation at break among the resin groups generally called thermoplastic resins, and can be suitably used as the base material of the adhesive sheet.

[0063] Therefore, among the materials for the base material layer, the proportion (mass%) of the styrene-based resin relative to all resin components is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, further preferably 65 to 100 mass%, and particularly preferably 70 to 100 mass%. By making the proportion of the styrene-based resin within the above preferred range, a base material layer with excellent elongation at break and breaking stress can be obtained.

[0064] The styrene resin described above may be, for example, a styrene resin having a single structure such as a linear structure, a branched structure, or a multi-branched structure, or styrene resins having different structures may be used in combination. A styrene resin rich in a linear structure can impart excellent elongation at break to the substrate layer. On the other hand, a styrene resin having a branched structure or a multi-branched structure and having a styrene block at the molecular end can adopt a pseudo-crosslinked structure and can impart excellent cohesive force. Therefore, the styrene resin is preferably used in combination according to the required mechanical properties.

[0065] As the styrene resin, relative to the total mass of the styrene resin, a styrene resin containing a structural unit represented by the following chemical formula (A) in a range of 5 to 50% by mass is preferably used, a styrene resin containing a structural unit represented by the following chemical formula (A) in a range of 5 to 40% by mass is more preferably used, a styrene resin containing a structural unit represented by the following chemical formula (A) in a range of 10 to 30% by mass is further preferably used, and a styrene resin containing a structural unit represented by the following chemical formula (A) in a range of 15 to 25% by mass is particularly preferably used. By making the proportion of the structural unit represented by the following chemical formula (A) relative to the total mass of the styrene resin within the above preferred range, it is easy to obtain an elongation at break and a breaking stress within a suitable range. It should be noted that * in the following chemical formula (A) represents the bonding position to other atoms, and the same applies to the following chemical formula (B) and chemical formulas (1) to (3).

[0066] [Chemical formula 3]

[0067]

[0068] As the styrene resin, in the case of using a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer in combination, the content of the styrene-isoprene copolymer is preferably 0 to 80% by mass, more preferably in the range of 0 to 70% by mass, further preferably 0 to 50% by mass, and particularly preferably 0 to 30% by mass relative to the total mass of the styrene-isoprene copolymer and the styrene-isoprene-styrene copolymer. If the content of the styrene-isoprene copolymer is within the above preferred range, it is possible to balance thermal durability while maintaining excellent elongation at break and breaking stress.

[0069] In addition, as the styrene-isoprene copolymer, a styrene-isoprene copolymer having a weight-average molecular weight of 10,000 to 800,000 in terms of standard polystyrene measured by gel permeation chromatography (GPC) is preferably used, a styrene-isoprene copolymer in the range of 30,000 to 500,000 is more preferably used, and a styrene-isoprene copolymer in the range of 50,000 to 300,000 is further preferably used. By making the weight-average molecular weight of the styrene-isoprene copolymer within the above-mentioned preferred range, heat flowability and compatibility during solvent dilution can be ensured, so the workability in the manufacturing process is good, and a substrate layer with thermal durability can be obtained, which is therefore preferred.

[0070] Here, the measurement of the weight-average molecular weight of the styrene-isoprene copolymer based on the GPC method is the value in terms of standard polystyrene measured using a GPC device (SC-8020, manufactured by Tosoh Corporation), and the measurement conditions are as described below.

[0071] - Measurement conditions -

[0072] · Sample concentration: 0.5 mass% (tetrahydrofuran solution)

[0073] · Sample injection volume: 100 μL

[0074] · Eluent: Tetrahydrofuran

[0075] · Flow rate: 1.0 mL / minute

[0076] · Measurement temperature: 40 °C

[0077] · Main column: 2 pieces of TSKgel (registered trademark) GMHHR-H(20)

[0078] · Guard column: TSKgel HXL-H

[0079] · Detector: Differential refractometer

[0080] · Standard polystyrene molecular weight: 10,000 to 20,000,000 (manufactured by Tosoh Corporation)

[0081] As the manufacturing method of the styrene-isoprene copolymer, styrene-isoprene-styrene copolymer, and the mixture of styrene-isoprene copolymer and styrene-isoprene-styrene copolymer, there is no particular limitation, and it can be appropriately selected from the conventionally known manufacturing methods. The block copolymer can be obtained by an anionic living polymerization method, and a coupling agent can be added and reacted as needed.

[0082] Specifically, as a method for manufacturing a styrene-isoprene copolymer, there is no particular limitation, and it can be appropriately selected from conventionally known manufacturing methods. For example, a method of sequentially polymerizing a styrene block and an isoprene block by an anionic living polymerization method can be cited, etc.

[0083] As a method for manufacturing a styrene-isoprene-styrene copolymer, there is no particular limitation, and it can be appropriately selected from conventionally known manufacturing methods. For example, a method of sequentially polymerizing a styrene block and an isoprene block by an anionic living polymerization method, a method of manufacturing a block copolymer having a living polymerization active end and then reacting with a coupling agent for coupling to manufacture a block copolymer, etc. can be cited.

[0084] As a method for manufacturing a mixture of a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer, there is no particular limitation, and it can be appropriately selected from conventionally known manufacturing methods. For example, a method of mixing a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer manufactured by the above method can be cited, etc.

[0085] In addition, as a method for manufacturing a mixture of a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer, it can also be manufactured as a mixture in one polymerization step.

[0086] As a more specific mode, by an anionic living polymerization method, first, in a polymerization solvent, a styrene monomer is polymerized using an anionic polymerization initiator to form a polystyrene block having a living polymerization active end. Second, isoprene is polymerized starting from the living polymerization active end of the polystyrene block to obtain a styrene-isoprene diblock copolymer having a living polymerization active end. Third, a part of the styrene-isoprene diblock copolymer having a living polymerization active end is reacted with a coupling agent to form a coupled styrene-isoprene-styrene block copolymer. Fourth, for the remaining part of the styrene-isoprene diblock copolymer having a living polymerization active end, a polymerization terminator is used to deactivate its living polymerization active end to form a styrene-isoprene diblock copolymer. In addition, this styrene-isoprene diblock copolymer can be used as the vinyl aromatic block copolymer.

[0087] As the polyurethane resin, there is no particular limitation, and it can be appropriately selected according to the purpose. A polyurethane resin having a softening point of 45°C or higher is preferred, and a polyurethane resin having a softening point of 55°C or higher is more preferred. In addition, as the upper limit of the softening point, it is preferably 110°C or lower. The "softening point" in this specification refers to the value measured according to JIS K 2207 (ring and ball method) (hereinafter, the softening point is the same measurement method).

[0088] As the polyurethane resin, a reaction product of a polyol (b1-1) and a polyisocyanate (b1-2) is preferably used.

[0089] As the polyol (b1-1), there is no particular limitation, and it can be appropriately selected according to the purpose. For example, polyester polyols, polyether polyols, polycarbonate polyols, acrylic polyols, etc. can be cited. They can be used alone or in combination of two or more. Among them, as the polyol (b1-1), polyester polyols and polyether polyols can obtain the mechanical properties of the substrate layer, and are therefore preferred. In the substrate layer, polyester polyols are preferably used when heat resistance is required, and polyether polyols are preferably used when water resistance and biodegradability resistance are required.

[0090] As the polyester polyol, for example, polyesters obtained by esterifying low molecular weight polyols with polycarboxylic acids, polyesters obtained by ring-opening polymerization of cyclic ester compounds such as ε-caprolactone, and their copolyesters can be cited.

[0091] As the low molecular weight polyols that can be used in the production of the polyester polyol, for example, aliphatic alkylene diols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, 1,3-butanediol, etc. with a weight average molecular weight of approximately 60 to 280, and cyclohexanedimethanol can be used.

[0092] As the polycarboxylic acid, for example, aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, dodecanedioic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid; and their acid anhydrides or esterified products, etc. can be cited.

[0093] As the polyether polyol, for example, polyether polyols obtained by addition polymerization of alkylene oxides using one or more of the compounds having two or more active hydrogen atoms as an initiator can be cited.

[0094] As the polycarbonate polyol, for example, polycarbonate polyols obtained by reacting a carbonate and / or phosgene with the low molecular weight polyols described below can be used.

[0095] As the carbonate, for example, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclic carbonate, diphenyl carbonate, etc. can be cited.

[0096] Examples of low-molecular-weight polyols that can be used to produce the polycarbonate polyol and that can react with carbonates and / or phosgene include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcinol, bisphenol A, bisphenol F, 4,4'-biphenol, and the like.

[0097] There are no particular restrictions on the polyisocyanate (b1-2), and it can be appropriately selected according to the purpose. For example, alicyclic polyisocyanates, aliphatic polyisocyanates, aromatic polyisocyanates, etc. can be used, and alicyclic polyisocyanates, etc. can be cited. They can be used alone or in combination of two or more.

[0098] Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 4,4'-dicyclohexylmethane diisocyanate, 2,4-methylcyclohexane diisocyanate, 2,6-methylcyclohexane diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexylene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate, dimer acid diisocyanate, bicycloheptane triisocyanate, and the like. They can be used alone or in combination of two or more.

[0099] There are no particular restrictions on the method for producing the polyurethane resin (b1) by reacting the polyol (b1-1) with the polyisocyanate (b1-2), and it can be appropriately selected from conventionally known production methods. For example, the following methods, etc. can be cited: After removing moisture by heating the polyol (b1-1) charged into the reaction vessel under normal pressure or reduced pressure, the polyisocyanate (b1-2) is supplied all at once or in batches to cause a reaction.

[0100] The reaction of the polyol (b1-1) and the polyisocyanate (b1-2) is preferably carried out in the range where the equivalent ratio of the isocyanate group (NCO) in the polyisocyanate (b1-2) to the hydroxyl group (OH) in the polyol (b1-1) (NCO / OH equivalent ratio) is from 1.0 to 20.0, more preferably in the range from 1.1 to 13.0, further preferably in the range from 1.2 to 5.0, and particularly preferably in the range from 1.5 to 3.0.

[0101] As the reaction conditions for the polyol (b1-1) and the polyisocyanate (b1-2), there are no particular limitations, and they can be appropriately selected considering various conditions such as safety, quality, and cost; as the reaction temperature, it is preferably 70 to 120 °C, and as the reaction time, it is preferably 30 minutes to 5 hours.

[0102] When reacting the polyol (b1-1) and the polyisocyanate (b1-2), if necessary, as the catalyst, for example, a tertiary amine catalyst, an organometallic catalyst, etc. can be used.

[0103] In addition, the said reaction can be carried out in a solvent-free environment or in the presence of an organic solvent.

[0104] As the organic solvent, there are no particular limitations, and it can be appropriately selected according to the purpose. For example, there can be mentioned ester solvents such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, etc.; ketone solvents such as acetone, methyl ethyl ketone, methyl butyl ketone, cyclohexanone, etc.; ether ester solvents such as methyl cellosolve acetate, butyl cellosolve acetate, etc.; aromatic hydrocarbon solvents such as toluene, xylene, etc.; amide solvents such as dimethylformamide, dimethylacetamide, etc. They can be used alone as one kind or in combination of two or more kinds.

[0105] The organic solvent can be removed by appropriate methods such as reduced-pressure heating, atmospheric drying, etc. during the manufacturing process of the polyurethane resin (b1) or after manufacturing the polyurethane (b1).

[0106] As other components in the base material layer, there are no particular limitations, and they can be appropriately selected within the range that does not impair the characteristics of the adhesive tape. For example, there can be mentioned tackifying resins; polymer components other than the material of the base material layer; crosslinking agents, anti-aging agents, ultraviolet absorbers, fillers, polymerization inhibitors, surface modifiers, antistatic agents, defoaming agents, viscosity regulators, light stabilizers, weather stabilizers, heat stabilizers, antioxidants, leveling agents, organic pigments, inorganic pigments, pigment dispersants, silica beads, organic beads, etc. additives; inorganic fillers such as silica, alumina, titanium oxide, zirconium oxide, antimony pentoxide, etc. They can be used alone as one kind or in combination of two or more kinds.

[0107] The content of other components in the base material layer can be appropriately selected within the range that does not impair the characteristics of the adhesive tape.

[0108] The tackifying resin can be used for the purpose of improving the adhesion between the adhesive layer and the substrate layer of the adhesive tape and improving the heat resistance.

[0109] As the tackifying resin, there is no particular limitation, and it can be appropriately selected according to the purpose. A tackifying resin with a softening point of 80 °C or higher is preferred, a tackifying resin with a softening point of 90 °C or higher is more preferred, a tackifying resin with a softening point of 100 °C or higher is further preferred, and a tackifying resin with a softening point of 110 °C or higher is particularly preferred.

[0110] As the tackifying resin, for example, the tackifying resin described in the item of "rubber-based adhesive resin" described later can be used, and the preferred methods are the same.

[0111] As the anti-aging agent, there is no particular limitation, and it can be appropriately selected from known anti-aging agents according to the purpose. For example, phenolic anti-aging agents, phosphorus-based anti-aging agents (sometimes also called "processing stabilizers"), amine-based anti-aging agents, imidazole-based anti-aging agents, etc. can be cited. They can be used alone or in combination of two or more. Among them, phenolic anti-aging agents and phosphorus-based anti-aging agents are preferred. When they are used in combination, the heat resistance stability of the substrate material can be effectively improved. As a result, an adhesive tape that maintains good initial adhesiveness and has further excellent heat durability can be obtained, so it is preferred. It should be noted that the phosphorus-based anti-aging agent may slightly change color (yellowing) over time in a high-temperature environment. Therefore, the amount of its use is preferably set appropriately considering the balance among the initial adhesiveness, heat durability, and prevention of color change.

[0112] As the phenolic anti-aging agent, phenolic compounds having a sterically hindered group are usually used, and monophenol type, bisphenol type, and polyphenol type are representative. As specific examples, 2,6-di-tert-butyl-4-methylphenol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), tetra-[methylenepropionate-3-(3',5'-di-tert-butyl-4-hydroxyphenyl) ester] methane, n-octadecyl propionate-3-(4'-hydroxy-3',5'-di-tert-butylphenyl) ester, etc. can be cited. They can be used alone or in combination of two or more.

[0113] Regarding the amount of the phenolic anti-aging agent used, there is no particular limitation, and it can be appropriately selected according to the purpose. Relative to 100 parts by mass of the substrate material, it is preferably used in the range of 0.1 part by mass to 5 parts by mass, and when used in the range of 0.5 part by mass to 3 parts by mass, the heat resistance stability of the substrate material can be effectively improved. As a result, an adhesive tape that maintains good initial adhesiveness and has further excellent heat durability can be obtained.

[0114] The adhesive layer in the present invention must contain an adhesive resin containing a terpolymer represented by the following general formula (1) as a main component, a tackifying resin, and may also contain a filler as needed. In addition, the adhesive layer in the present invention is formed from an adhesive composition containing an adhesive resin containing a terpolymer represented by the following general formula (1) as a main component, a tackifying resin, and a filler and / or other components added as needed.

[0115] The 25% elongation stress of the adhesive layer is not particularly limited and can be appropriately selected according to the purpose. It is preferably 0.04 MPa to 0.4 MPa, more preferably 0.05 MPa to 0.1 MPa. If the 25% elongation stress of the adhesive layer is within the preferred range, the bonding strength suitable for an adhesive tape can be obtained, and it is possible to relatively easily pull and peel even during elongation peeling. On the other hand, if the 25% elongation stress of the adhesive layer is less than 0.04 MPa, the adhesive tape may peel when a load is generated in the shear direction of the adhesive tape while fixing hard adherends to each other. If it exceeds 0.4 MPa, the force required to elongate the adhesive tape may become too large when pulling and peeling the adhesive tape.

[0116] In the present embodiment, the storage modulus G'(23 °C) of the adhesive layer is preferably 1.0×10 5 ~1.0×10 7 Pa, more preferably 1.0×10 5 ~1.0×10 6 Pa, further preferably 1.5×10 5 ~9.0×10 5 Pa, even more preferably 2.0×10 5 ~8.0×10 5 Pa. If the storage modulus G'(23 °C) of the adhesive layer is within the above range, the effects of highly balancing initial adhesiveness, high load holding force, and re-peelability over time can be achieved. In addition, by making the breaking point stress of the adhesive layer within the above range, it is possible to easily follow the deformation of the adherend, etc., easily obtain excellent bonding strength, and ensure the dimensional stability of the base material layer, so that suitable attachment workability can be obtained.

[0117] The 25% elongation stress of the adhesive layer means: The adhesive layer is punched into a dumbbell shape with a gauge length of 20 mm and a width of 10 mm, and under the conditions of a measurement atmosphere of 23 °C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched in the length direction at a stretching speed of 300 mm / minute, and the stress value measured when it elongates by 25% is measured.

[0118] The breaking stress of the adhesive layer is not particularly limited and can be appropriately selected according to the purpose. It is preferably 0.6 to 5.0 MPa, more preferably 1.0 to 4.0 MPa. If the breaking stress of the adhesive layer is within the above-mentioned preferred range, when the adhesive tape is stretched and peeled off, the adhesive tape can be inhibited from breaking, and the load for stretching the adhesive tape will not become too large. Therefore, the re-peeling operation by stretching and peeling becomes easy. On the other hand, if the breaking stress of the adhesive layer is less than 0.6 MPa, sometimes residual glue may occur due to cohesive failure of the adhesive layer when the adhesive tape is stretched and peeled off; if it exceeds 5.0 MPa, sometimes sufficient adhesiveness may not be obtained. It should be noted that the force required to stretch and deform the adhesive tape also depends on the thickness of the adhesive tape. For example, when trying to stretch and peel off an adhesive tape with a thick thickness and a high breaking stress, sometimes it may not be possible to stretch it sufficiently to peel it off.

[0119] The breaking stress of the adhesive layer refers to: the adhesive layer is punched into a dumbbell shape with a gauge length of 20 mm and a width of 10 mm, and under the conditions of a measurement atmosphere of 23 °C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched in the longitudinal direction at a stretching speed of 300 mm / min, and the stress value measured when fracture occurs.

[0120] The breaking elongation rate of the adhesive layer is not particularly limited and can be appropriately selected according to the purpose. It is preferably 450 to 1300%, more preferably 500 to 1200%, and further preferably 600 to 1100%. By making the breaking elongation rate of the adhesive layer within the above-mentioned preferred range, appropriate adhesiveness and re-peeling property (easy peeling property) can be balanced.

[0121] The breaking elongation rate of the adhesive layer refers to: the adhesive layer is punched into a dumbbell shape with a gauge length of 20 mm and a width of 10 mm, and under the conditions of a measurement atmosphere of 23 °C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched in the longitudinal direction at a stretching speed of 300 mm / min, and the tensile elongation rate measured when fracture occurs.

[0122] The average thickness of the adhesive layer is not particularly limited and can be appropriately selected according to the purpose. It is preferably 1 to 200 μm, more preferably 10 to 150 μm, further preferably 30 to 120 μm, and particularly preferably 40 μm to 100 μm. The "average thickness of the adhesive layer" refers to the thickness of the adhesive layer on one side of the adhesive tape. When the adhesive tape has adhesive layers on both sides, the average thickness of the adhesive layer on one side and the average thickness of the adhesive layer on the other side can be the same or different, and the same thickness is preferred.

[0123] It should be noted that in this specification, the average thickness of the adhesive layer can be measured by the following method. That is, after immersing the adhesive tape in liquid nitrogen for 1 minute, use tweezers to bend and cut it in the liquid nitrogen with the width direction of the adhesive tape as the crease to prepare a section for observing the cross-section in the thickness direction of the adhesive tape. After restoring the section to room temperature in a dryer, fix it on the specimen stage in such a way that the electron beam is incident perpendicularly to the cross-section, and use an electron microscope to observe the cross-section. Based on the magnification of the electron microscope, measure the thickness of the adhesive layer at 10 positions of the adhesive tape, and take the arithmetic mean as the thickness of the adhesive layer. It should be noted that the thickness of the adhesive layer is the length measured along the stacking direction from one surface to the other surface.

[0124] As the main component of the adhesive resin used in the adhesive layer of the present invention, it preferably contains a triblock copolymer represented by the following general formula (1). The "main component of the adhesive resin" in this specification refers to the main component of the resin component contained in the adhesive resin (typically, a component containing more than 50% by mass). In addition, relative to the entire adhesive resin used in the adhesive layer of the present invention, it is preferable that the triblock copolymer represented by the following general formula (1) accounts for 30 to 100% by mass, and more preferably the triblock copolymer represented by the general formula (1) accounts for 50 to 95% by mass.

[0125] In the adhesive layer of the present invention, if the content of the triblock copolymer is 30 to 100% by mass, it is easy to balance high load holding force and adhesion.

[0126] As the adhesive resin of the present invention, it contains a triblock copolymer having repeating units represented by the general formula (1):

[0127] [Chemical formula 4]

[0128]

[0129] (In the above general formula (1), A, B, and C each independently represent a repeating unit, A and C each independently represent a methacrylic acid alkyl ester monomer unit, B represents an acrylic acid alkyl ester monomer unit, p, q, and r each independently represent the degree of polymerization of each monomer unit, and A and C may be the same or may be methacrylic acid alkyl ester monomer units having different chemical structures. In the above general formula (1), * is a bonding position indicating the bonding with other atoms.).

[0130] The adhesive layer containing the triblock copolymer can ensure a high elastic modulus, and thus it is easy to ensure high load retention, re-peelability over time, and adhesive force with excellent storage stability. In particular, when stretching the adhesive tape, in the case where a filler is included in the adhesive layer, compared with the form where no filler is present in the adhesive layer, the state where the filler in the adhesive layer exposes the surface can be maintained for a long time, and thus a synergistic effect is exerted in combination with the effect of the filler.

[0131] In the above general formula (1), A and C represent repeating units different from B, and represent alkyl methacrylate monomer units. In addition, A and C are each independent and may be the same alkyl methacrylate monomer unit as each other, or may be alkyl methacrylate monomer units having different chemical structures. The "alkyl methacrylate monomer unit" in the present specification refers to the structural unit derived from the alkyl methacrylate monomer when the alkyl methacrylate monomer is (co)polymerized or graft-polymerized, that is, the repeating unit derived from the methacrylate monomer. The alkyl methacrylate monomer unit in the present invention is preferably represented by the following general formula (2):

[0132] [Chemical formula 5]

[0133]

[0134] (In the above general formula (2), R 1 represents an alkyl group having 1 to 12 carbon atoms, and one or more hydrogen atoms in the alkyl group may be substituted by a substituent R 2 , and the substituent R 2 represents a halogen atom, an amino group, or a cyano group.).

[0135] In the above general formula (2), from the viewpoints of re-peelability and high load retention, R 1 is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably an alkyl group having 1 to 2 carbon atoms.

[0136] In the general formula (2), the alkyl group having 1 to 12 carbon atoms may be linear, branched, or cyclic; from the viewpoint of adhesive force, it is preferably linear or branched, and more preferably linear.

[0137] In the general formula (2), examples of the alkyl group having 1 to 12 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, hexyl, octyl, nonyl, decyl, undecyl, and dodecyl; and cyclic alkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, dicyclopentyl, and adamantyl. Among them, from the viewpoints of re-peelability and high load retention, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, or tert-butyl is preferred, and methyl, ethyl, and propyl are more preferred.

[0138] In the above general formula (2), examples of the alkyl group having 1 to 4 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, and tert-butyl; and cyclic alkyl groups such as cyclobutyl. As the alkyl group having 1 to 4 carbon atoms, from the viewpoints of re-peelability and high load retention, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, and tert-butyl are preferred, and methyl is more preferred.

[0139] Therefore, the preferred R in the above general formula (2) 1 is any one of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, or cyclobutyl, and one or more hydrogen atoms in the alkyl group may be substituted by the following groups: halogen atom, amino group, cyano group, linear or branched alkyl group (methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, hexyl, octyl, nonyl, decyl, undecyl, or dodecyl), or cyclic alkyl group (cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, dicyclopentyl, or adamantyl).

[0140] In the present embodiment, for example, the alkyl methacrylate monomer is not particularly limited, and examples thereof include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, tridecyl methacrylate, and 2-hexyldecyl methacrylate. Among them, from the viewpoints of high load retention and disassemblability, methyl methacrylate is preferred.

[0141] In the general formula (1), B represents a repeating unit different from A and C, and represents an acrylic acid alkyl ester monomer unit. The "acrylic acid alkyl ester monomer unit" in this specification refers to the structural unit derived from the acrylic acid alkyl ester monomer when the acrylic acid alkyl ester monomer is (co)polymerized or graft-polymerized, that is, the repeating unit derived from the acrylate monomer. The acrylic acid alkyl ester monomer unit in the present invention is preferably represented by the following general formula (3):

[0142] [Chemical formula 6]

[0143]

[0144] (In the above general formula (3), R 3 represents an alkyl group having 1 to 12 carbon atoms, and one or more hydrogen atoms in the alkyl group may be substituted by a substituent R 4 , and the substituent R 4 represents a halogen atom, an amino group, or a cyano group.).

[0145] In the above general formula (3), from the viewpoint of adhesiveness, R 3 is more preferably an alkyl group having 1 to 12 carbon atoms, and further preferably an alkyl group having 4 to 8 carbon atoms.

[0146] In the above general formula (3), the alkyl group having 1 to 12 carbon atoms may be linear, branched, or cyclic; from the viewpoint of adhesiveness, it is preferably linear or branched. In addition, the examples of the alkyl group having 1 to 12 carbon atoms are the same as those of the alkyl group having 1 to 12 carbon atoms in the above general formula (2).

[0147] Therefore, preferred R 3 in the above general formula (3) is a linear or branched alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, hexyl, octyl, nonyl, decyl, undecyl, or dodecyl, or a cyclic alkyl group such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, dicyclopentyl, or adamantyl; one or more hydrogen atoms in these alkyl groups may be substituted by a halogen atom, an amino group, or a cyano group.

[0148] In the present embodiment, examples of the acrylic acid alkyl ester monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isopentyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, etc. Among them, from the viewpoint of balancing the adhesive force and the re-peelability, n-butyl acrylate, 2-ethylhexyl acrylate, and their copolymers are preferred.

[0149] In the above general formula (1), p, q, and r each independently represent the degree of polymerization of each monomer unit. The respective values of p, q, and r are related to the molecular weight and the like. p / (p + q + r) is preferably 0.02 to 0.40, more preferably 0.05 to 0.37. q / (p + q + r) is preferably 0.20 to 0.95, more preferably 0.25 to 0.90. r / (p + q + r) is preferably 0.02 to 0.40, more preferably 0.05 to 0.37.

[0150] In the present embodiment, the triblock copolymer preferably has repeating units represented by the following general formula (4):

[0151] [Chemical formula 7]

[0152]

[0153] (In the above general formula (4), R 1 and R 5 each independently represent an alkyl group having 1 to 12 carbon atoms, and one or more hydrogen atoms in the alkyl group may be substituted by a substituent R 2 , the substituent R 2 represents a halogen atom, an amino group, or a cyano group, R 3 represents an alkyl group having 1 to 20 carbon atoms, and one or more hydrogen atoms in the alkyl group may be substituted by a substituent R 4 , the substituent R 4 represents a halogen atom, an amino group, a cyano group, or an alkyl group having 1 to 20 carbon atoms, and p, q, and r each independently represent the degree of polymerization of each monomer unit.).

[0154] In the above general formula (4), R 1 can have the same form as R 1 in the above general formula (2). In the above general formula (4), R 3 can have the same form as R 3 in the above general formula (3). In the above general formula (4), R 5 can have the same form as R 1 in the above general formula (2). Further, in the above general formula (4), p, q, and r can have the same form as p, q, and r in the above general formula (1). In addition, in the above general formula (4), R 1 and R 5 can be the same or different.

[0155] In the present embodiment, when the triblock copolymer is represented by the above general formula (4), R 1 is preferably selected from linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and cyclobutyl, and R 3Preferably selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, hexyl, octyl, nonyl, decyl, and undecyl, R 5 Preferably selected from linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc., and cyclobutyl. Preferably, p / (p + q + r) is 0.02 to 0.40, q / (p + q + r) is 0.20 to 0.95, and r / (p + q + r) is 0.02 to 0.40.

[0156] In the triblock copolymer of the present invention, preferably A and C in the general formula (1) are the same. Specifically, when the triblock copolymer has the repeating unit represented by the above general formula (4), preferably R 1 and R 5 are the same group, p / (p + q + r) is 0.02 to 0.40, q / (p + q + r) is 0.20 to 0.95, and r / (p + q + r) is 0.02 to 0.40.

[0157] In the triblock copolymer having the repeating unit represented by the above general formula (1), when A and C are the same (A - B - A type triblock copolymer), a higher elastic modulus can be ensured. Therefore, it is easier to ensure the adhesive force and exhibit excellent high load holding force, re-peelability over time, and storage stability.

[0158] In the present embodiment, preferably, the weight average molecular weight Mw of the triblock copolymer is 50,000 to 300,000, and the number average molecular weight Mn is 50,000 to 300,000. More preferably, the weight average molecular weight Mw of the triblock copolymer is 100,000 to 250,000, and the number average molecular weight Mn is 100,000 to 250,000. Further preferably, the weight average molecular weight Mw of the triblock copolymer is 130,000 to 230,000, and the number average molecular weight Mn is 130,000 to 230,000.

[0159] If the weight average molecular weight Mw of the triblock copolymer is within the above range, it is preferred from the viewpoint of balancing adhesiveness, re-peelability, and high load holding force; if the number average molecular weight Mn of the triblock copolymer is within the above range, it is preferred from the viewpoint of balancing adhesiveness, re-peelability, and high load holding force.

[0160] Here, the weight average molecular weight M W and number average molecular weight M N of the triblock polymer based on the GPC method are standard polystyrene conversion values measured using a GPC device (HLC - 8329GPC, manufactured by Tosoh Corporation), and the measurement conditions are as follows.

[0161] [Measurement Conditions]

[0162] · Sample concentration: 0.5 mass% (tetrahydrofuran (THF) solution)

[0163] · Sample injection volume: 100 μL

[0164] · Eluent: THF

[0165] · Flow rate: 1.0 mL / min

[0166] · Measurement temperature: 40 °C

[0167] · Main column: 2 pieces of TSKgel GMHHR-H(20)

[0168] · Guard column: TSKgel HXL-H

[0169] · Detector: Differential refractometer

[0170] · Standard polystyrene molecular weight: 10,000 - 20,000,000 (manufactured by Tosoh Corporation)

[0171] The triblock copolymer of the present invention and / or a partial structure (e.g., block) of the triblock copolymer preferably has stereoregularity (stereoregularity degree). Specifically, the triblock copolymer of the present invention and / or a partial structure (e.g., block) of the triblock copolymer may have any one of isotactic, syndiotactic, and atactic stereoregularities, or may have a plurality of blocks having any one of these stereoregularities.

[0172] As a preferred embodiment of the triblock copolymer in the present invention, it is preferred that the syndiotacticity of the polymer block representing the "-(A) p -" part in the general formula (1) exhibits a proportion of rr triads of 65% or more, and more preferably the proportion of rr triads is 75 - 95%.

[0173] As a preferred embodiment of the triblock copolymer in the present invention, it is preferred that the syndiotacticity of the polymer block representing the "-(C) r -" part in the general formula (1) exhibits a proportion of rr triads of 65% or more, and more preferably the proportion of rr triads is 75 - 95%.

[0174] As a preferred embodiment of the triblock copolymer in the present invention, the polymer block representing the "-(B) r -" part in the general formula (1) preferably exhibits atacticity.

[0175] When the triblock copolymer in the present invention has a polymer block representing the "-(A) p -" part with a proportion of rr triads of 65% or more, the effects of good re-peelability and good holding force at high temperatures can be achieved.

[0176] Generally, the syndiotacticity of a polymer is represented by the ratio of rr in a chain composed of three monomer units (triad). In this specification, it is calculated by NMR measurement of the polymer. Specifically, 13 The signal peaks representing the arrangement of triads in C-NMR vary depending on conditions such as the type of polymer, the measurement solvent, or the measurement temperature. Therefore, it is necessary to identify and quantify the signals according to the respective measurement conditions. It should be noted that in this specification, the measurement is performed at 50 °C on a sample dissolved in deuterated chloroform.

[0177] As a preferred form of the triblock copolymer in the present invention, examples include polymethyl methacrylate block - poly(n-butyl acrylate) block - polymethyl methacrylate, polyethyl methacrylate block - poly(n-butyl acrylate) block - polyethyl methacrylate, polypropyl methacrylate block - poly(n-butyl acrylate) block - polypropyl methacrylate, polymethyl methacrylate block - poly(tert-butyl acrylate) block - polymethyl methacrylate, and polymethyl methacrylate block - polypropyl acrylate block - polymethyl methacrylate.

[0178] Regarding the triblock copolymer in the present invention, the molecular weight distribution of the whole triblock copolymer is represented by the ratio of weight-average molecular weight to number-average molecular weight, and is preferably in the range of 1.0 to 2.3, more preferably in the range of 1.00 to 1.50.

[0179] In this embodiment, when A and C in the general formula (1) are different repeating units, from the viewpoint of adhesion characteristics, the total weight of the polymer block of the "-(A) p -" part contained in the molecule of the triblock copolymer of the present invention (the total weight of the polymer block of this "-(A) p -" part is referred to as a.) and the total weight of the polymer block of the "-(B) q -" part (the total weight of the polymer block of this "-(B) q -" part is referred to as b.) are represented by the mass ratio of a / b, and are preferably in the range of 2 / 98 to 67 / 33, more preferably in the range of 5 / 95 to 60 / 40.

[0180] In this embodiment, when A and C in the general formula (1) are different repeating units, from the viewpoint of adhesion characteristics, the total weight of the polymer block of the "-(C) r -" part contained in the molecule of the triblock copolymer of the present invention (the total weight of the polymer block of this "-(C) p -" part is referred to as c.) and the total weight of the polymer block of the "-(B) q -" part are represented by the mass ratio of c / b, and are preferably in the range of 2 / 98 to 67 / 33, more preferably in the range of 5 / 95 to 60 / 40.

[0181] In this embodiment, when A and C in the general formula (1) are the same repeating unit, from the viewpoint of adhesion characteristics, the polymer block of the "-(A) p -" part and the polymer block of the "-(C) r -" part contained in the molecule of the triblock copolymer of the present invention (the total weight of the polymer block of the "-(A) p -" part and the polymer block of the "-(C) r -" part is referred to as d.) and the total weight of the polymer block of the "-(B) q -" part (referred to as b) are represented by the mass ratio of d / b, preferably in the range of 5 / 95 to 80 / 20, more preferably in the range of 10 / 90 to 75 / 25.

[0182] The triblock copolymer of the present invention can be modified with functional groups such as hydroxyl group, carboxyl group, acid anhydride group, amino group, trimethoxysilyl group, etc. in the molecular side chain or at the end of the molecular main chain as needed within the range that does not impair the effects of the present invention.

[0183] The method for producing the triblock copolymer used in this embodiment is not particularly limited, and can be appropriately selected from conventionally known production methods. For example, a method of successively polymerizing block copolymers by anionic living polymerization method, cationic living polymerization method, etc. can be cited. In addition, when the triblock copolymer used in this embodiment has stereoregularity (for example, syndiotacticity), a known method using an organometallic complex can be used.

[0184] As an example of the method for producing the triblock copolymer of the present invention, the triblock copolymer can be produced by the following method: in an inert polymerization solvent, using a polymerization initiator, the polymerization of an alkyl methacrylate monomer as the main component and the polymerization of an alkyl acrylate monomer and / or a monomer mainly composed of an alkyl methacrylate monomer are successively carried out in a desired block connection order.

[0185] As a more specific mode of the method for producing the triblock copolymer, by anionic living polymerization method, first, an alkyl methacrylate monomer is polymerized in a polymerization solvent using a polymerization initiator to form a polyalkyl methacrylate block having a living polymerizable active end (corresponding to the "-(A) p -" part in the general formula (1)). Second, starting from the living polymerizable active end of the polyalkyl methacrylate, an alkyl acrylate monomer is polymerized to obtain a polyalkyl methacrylate-alkyl acrylate diblock copolymer having a living polymerizable active end (corresponding to the "-(A) p -(B) q- (A) part. Third, a part of the alkyl methacrylate-alkyl acrylate diblock copolymer having a living polymerizable active end is reacted with a coupling agent to form a coupled alkyl methacrylate-alkyl acrylate-alkyl methacrylate triblock copolymer (corresponding to “-(A)” in the general formula (1)) p -(B) q -(C) r - (C) part. At this time, if necessary, the polymerization is terminated by reacting with a polymerization terminator such as an alcohol.

[0186] Examples of the polymerization initiator include organometallic compounds such as organolithium compounds or organometallic complexes.

[0187] Examples of the organometallic complex include rare earth metal complexes having pentamethylcyclopentadienyl as a ligand, such as bis(pentamethylcyclopentadienyl)methyltetrahydrofuran samarium, bis(pentamethylcyclopentadienyl)methyltetrahydrofuran yttrium, etc. In addition, these organometallic complexes can be used in combination with alkylaluminum compounds such as trimethylaluminum.

[0188] Examples of the organolithium compound include alkyllithiums such as tert-butyllithium; compounds obtained by reacting alkyllithium with 1,1-diphenylethylene, diphenylmethane, etc. In addition, these organolithium compounds can be used in combination with inorganic salts such as lithium chloride, lithium salts of alcoholates such as 2-(2-methoxyethoxy)ethoxylithium, and organoaluminum compounds such as diisobutyl(2,6-di-tert-butyl-4-methylphenoxy)aluminum.

[0189] As the polymerization solvent, hydrocarbon solvents such as benzene, toluene, and xylene; halogenated hydrocarbon solvents such as chloroform, dichloromethane, and carbon tetrachloride; ether solvents such as tetrahydrofuran and diethyl ether can be used.

[0190] As the main component of the adhesive resin used in the adhesive layer of the present invention, the triblock copolymer represented by the general formula (1) is included. As the resin other than the triblock copolymer represented by the general formula (1), there is no particular limitation, and examples include diblock copolymers, acrylic adhesive resins, or rubber-based adhesive resins.

[0191] As the adhesive resin in the present invention, a diblock copolymer having a repeating unit represented by the general formula (5) can be included:

[0192] [Chemical formula 8]

[0193]

[0194] (In the above general formula (5), D and E each independently represent a repeating unit, D represents an alkyl methacrylate monomer unit, E represents an alkyl acrylate monomer unit, and s and t each independently represent the degree of polymerization of each monomer unit. In the above general formula (5), * represents the bonding position to other atoms.).

[0195] In the present embodiment, when a triblock copolymer and a diblock copolymer are used in combination in the adhesive resin, it is easy to ensure a high elastic modulus and initial adhesiveness. Therefore, it is easier to ensure high load holding force, re-peelability over time, and initial adhesive force. Particularly when a filler is included in the adhesive layer, when stretching the adhesive tape, compared with the form where no filler exists in the adhesive layer, the state where the filler in the adhesive layer exposes on the surface can be maintained for a long time. Therefore, an excellent synergistic effect is exhibited in cooperation with the effect of the filler.

[0196] The alkyl methacrylate monomer unit and the alkyl acrylate monomer unit in the above general formula (5) can be in the same form as the alkyl methacrylate monomer unit and the alkyl acrylate monomer unit in the above general formula (1).

[0197] The diblock polymer in the present invention preferably has a repeating unit represented by the following general formula (6):

[0198] [Chemical formula 9]

[0199]

[0200] (In the above general formula (6), R 6 represents an alkyl group having 1 to 12 carbon atoms, and one or more hydrogen atoms in the alkyl group may be substituted by a substituent R 8 , the substituent R 8 represents a halogen atom, an amino group, or a cyano group, R 7 represents an alkyl group having 1 to 20 carbon atoms, and one or more hydrogen atoms in the alkyl group may be substituted by a substituent R 9 , the substituent R 9 represents a halogen atom, an amino group, a cyano group, or an alkyl group having 1 to 20 carbon atoms, and s and t each independently represent the degree of polymerization of each monomer unit.).

[0201] In the above general formula (6), R 6 can be in the same form as R 1 in the above general formula (2). In the above general formula (6), R 7 can be in the same form as R 3 in the above general formula (3). In the above general formula (6), s and t can be in the same form as p and q in the above general formula (1).

[0202] In addition, in the present embodiment, it is preferable that the weight-average molecular weight Mw of the diblock copolymer is 50,000 to 300,000, and the number-average molecular weight Mn is 50,000 to 300,000. The measurement of the weight-average molecular weight can refer to the method for measuring the weight-average molecular weight of the triblock copolymer in the present invention.

[0203] In the above general formula (6), p, q, and r each independently represent the degree of polymerization of each monomer unit. The values of s and t are related to the molecular weight and the like. s / (s + t) is preferably 0.01 to 0.99, more preferably 0.1 to 0.9. t / (s + t) is preferably 0.01 to 0.99, more preferably 0.1 to 0.9.

[0204] In the present embodiment, the content of the diblock copolymer is not particularly limited and can be appropriately selected according to the purpose. In the present embodiment, relative to 100 parts by mass of the triblock copolymer, it is preferably 0 to 100 parts by mass of the diblock copolymer, more preferably 1 to 50 parts by mass, and still more preferably 10 to 50 parts by mass. If the content range of the tackifying resin in the adhesive layer is within the above range, it is easy to ensure the adhesion to the adherend.

[0205] The acrylic adhesive resin is not particularly limited and can be appropriately selected according to the purpose. For example, resins containing an acrylic polymer and additives such as a tackifying resin and a crosslinking agent as required can be mentioned.

[0206] The acrylic polymer has a chemical structure other than the triblock copolymer represented by the above general formula (1), and can be produced, for example, by polymerizing a (meth)acrylate monomer.

[0207] As the (meth)acrylate monomer, for example, a (meth)acrylic acid alkyl ester having an alkyl group with 1 to 12 carbon atoms can be used.

[0208] Specific examples of the (meth)acrylic acid alkyl ester having an alkyl group with 1 to 12 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and the like. They can be used alone or in combination of two or more.

[0209] As the (meth)acrylic acid alkyl ester having an alkyl group with 1 to 12 carbon atoms, a (meth)acrylic acid alkyl ester having an alkyl group with 4 to 12 carbon atoms is preferably used, and a (meth)acrylic acid alkyl ester having an alkyl group with 4 to 8 carbon atoms is more preferably used; from the viewpoint of ensuring excellent adhesion to the adherend, n-butyl acrylate is particularly preferably used.

[0210] The alkyl (meth)acrylate having an alkyl group with 1 to 12 carbon atoms is preferably used in the range of 0 to 50% by mass, more preferably in the range of 0 to 30% by mass, relative to the total amount of monomers used in the production of the acrylic polymer.

[0211] As monomers that can be used in the production of the acrylic polymer, in addition to the above monomers, high-polarity vinyl monomers can also be used as needed.

[0212] Examples of high-polarity vinyl monomers include (meth)acrylic monomers having a hydroxyl group, (meth)acrylic monomers having a carboxyl group, (meth)acrylic monomers having an amide group such as (meth)acrylic acid monomers, vinyl acetate, ethylene oxide-modified succinic acid acrylate, monomers having a sulfonic acid group such as 2-acrylamide-2-methylpropanesulfonic acid, etc. They can be used alone or in combination of two or more.

[0213] Specific examples of vinyl monomers having a hydroxyl group include (meth)acrylic monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, etc.

[0214] Vinyl monomers having a hydroxyl group are preferably used when using a resin containing an isocyanate-based crosslinking agent as the binder resin. Specifically, as vinyl monomers having a hydroxyl group, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate are preferably used.

[0215] Vinyl monomers having a hydroxyl group are preferably used in the range of 0.01 to 1.0% by mass, more preferably in the range of 0.03 to 0.3% by mass, relative to the total amount of monomers used in the production of the acrylic polymer.

[0216] Specific examples of vinyl monomers having a carboxyl group include (meth)acrylic monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, (meth)acrylic acid dimer, crotonic acid, ethylene oxide-modified succinic acid acrylate, etc. Among them, acrylic acid is preferred.

[0217] Specific examples of vinyl monomers having an amide group include (meth)acrylic monomers such as N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, acrylamide, N,N-dimethylacrylamide, etc.

[0218] The high-polarity vinyl monomer is preferably used in the range of 1.5 to 20% by mass, more preferably in the range of 1.5 to 10% by mass, based on the total amount of the monomers used in the production of the acrylic polymer; when used in the range of 2 to 8% by mass, an adhesive layer having a balance in cohesive force, holding power, and adhesiveness can be formed, and thus it is further preferred.

[0219] As the method for producing the acrylic polymer, there is no particular limitation, and it can be appropriately selected from known methods according to the purpose. For example, methods of polymerizing monomers using polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, etc. can be cited. Among them, the acrylic polymer is preferably produced by solution polymerization or bulk polymerization.

[0220] During polymerization, if necessary, peroxide-based thermal polymerization initiators such as benzoyl peroxide and lauroyl peroxide; azo-based thermal polymerization initiators such as azobisisobutyronitrile; acetophenone-based photoinitiators; benzoin ether-based photoinitiators; benzil ketal-based photoinitiators; acylphosphine oxide-based photoinitiators; benzoin-based photoinitiators; benzophenone-based photoinitiators, etc. can be used.

[0221] Regarding the weight-average molecular weight of the acrylic polymer obtained by the above method, it is preferable to use an acrylic polymer having a weight-average molecular weight of 300,000 to 3,000,000 measured in terms of standard polystyrene by gel permeation chromatography (GPC) under the same method and conditions as those for the triblock copolymer, and it is more preferable to use an acrylic polymer having a weight-average molecular weight of 500,000 to 2,500,000.

[0222] Based on the total amount of the adhesive resin used in the adhesive layer in the present invention, the acrylic adhesive resin preferably accounts for 0 to 50% by mass, and more preferably accounts for 0 to 30% by mass.

[0223] In the adhesive layer in the present invention, if the content of the acrylic adhesive resin is within the above range, it is easy to balance adhesiveness, re-peelability over time, and high-load holding power.

[0224] As the rubber-based adhesive resin, there is no particular limitation, and resins containing rubber materials such as synthetic rubber-based adhesive resins and natural rubber-based adhesive resins that can generally be used as adhesive resins and additives such as tackifying resins as needed can be cited.

[0225] As a rubber material, for example, block copolymers of aromatic vinyl compounds and conjugated diene compounds can be mentioned. Specifically, styrene-isoprene copolymers, styrene-isoprene-styrene copolymers, styrene-isoprene-butadiene-styrene copolymers, styrene-butadiene-styrene copolymers, styrene-ethylene-butene copolymers, styrene-ethylene-propylene copolymers, and their hydrogenated products such as styrene-based resins can be mentioned. They can be used alone, or two or more of them can be used in combination. Among them, using two or more styrene-based resins in combination can impart excellent adhesive physical properties and holding power to the adhesive tape, so it is more preferred; it is particularly preferred to use a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer in combination.

[0226] As the styrene-based resin, a styrene-based resin having a single structure such as a linear structure, a branched structure, or a multi-branched structure can be used, or styrene-based resins having different structures can be mixed and used. When a styrene-based resin rich in a linear structure is used for the adhesive layer, excellent adhesive properties can be imparted to the adhesive tape. On the other hand, a structure having a branched structure or a multi-branched structure but having a styrene block at the molecular end can adopt a pseudo-crosslinked structure and can impart excellent cohesion, so high holding power can be imparted. Therefore, the styrene-based resin is preferably mixed and used according to the required characteristics.

[0227] As the styrene-based resin, relative to the total mass of the styrene-based resin, a styrene-based resin having a structural unit represented by the following chemical formula (B) in the range of 10 to 80% by mass is preferably used, a styrene-based resin having a structural unit represented by the following chemical formula (B) in the range of 12 to 60% by mass is more preferably used, a styrene-based resin having a structural unit represented by the following chemical formula (B) in the range of 15 to 40% by mass is further preferably used, and a styrene-based resin having a structural unit represented by the following chemical formula (B) in the range of 17 to 35% by mass is particularly preferably used. Thereby, excellent adhesiveness and heat resistance can be obtained.

[0228] [Chemical formula 10]

[0229]

[0230] Relative to the entire adhesive resin used in the adhesive layer in the present invention, it is preferred that the rubber-based adhesive resin accounts for 0 to 50% by mass, and more preferably the rubber-based adhesive resin accounts for 0 to 30% by mass.

[0231] In the adhesive layer in the present invention, if the content of the rubber-based adhesive resin is within the above range, it is easy to balance adhesiveness, disintegratability, and high-load holding power.

[0232] The adhesive layer of this embodiment contains a tackifying resin. This tackifying resin is preferably used to improve the adhesion and surface adhesion strength to the adherend.

[0233] As the tackifying resin of this embodiment, the softening point is preferably 95°C or higher. More preferably, the softening point is 95°C to 180°C; from the aspect of forming an adhesive layer with high adhesive performance, the softening point is more preferably 95°C to 140°C. It should be noted that when using a (meth)acrylate-based tackifying resin, its glass transition temperature is preferably 30°C to 200°C, more preferably 50°C to 160°C.

[0234] As the tackifying resin, a tackifying resin with a softening point (softening temperature) of 95°C or higher can be preferably used. By making the adhesive layer contain a tackifying resin with a softening point above the above lower limit value, an adhesive tape with more excellent adhesive force can be realized. Among the above-exemplified tackifying resins, a terpene-based tackifying resin (such as terpene-modified phenolic resin) and a rosin-based tackifying resin (such as an esterified product of polymerized rosin) having the above softening point can be preferably used. There is no particular limitation on the upper limit of the softening point of the tackifying resin. For example, it can be set to about 200°C or lower. It should be noted that the softening point of the tackifying resin mentioned here is defined as the value measured by the softening point test method (ring and ball method) specified in either JIS K 5902 or JIS K 2207.

[0235] Regarding the amount of the tackifying resin used, there is no particular limitation, and it can be appropriately selected according to the purpose. As this embodiment, relative to 100 parts by mass of the triblock copolymer, it is preferably to contain 10 to 75 parts by mass of the tackifying resin, more preferably 20 to 60 parts by mass, and further preferably 30 to 50 parts by mass. If the content range of the tackifying resin in the adhesive layer is within the above range, it is easy to ensure the adhesion to the adherend.

[0236] In this embodiment, the product of the temperature [°C] of the softening point of the tackifying resin and the addition amount of the tackifying resin (the addition amount of the tackifying resin when the triblock copolymer is set to 100 parts by mass) is preferably 1300 to 13000.

[0237] If the product of the softening point (temperature) of the tackifying resin and the addition amount of the tackifying resin is large, a bonding layer excellent in heat resistance can be formed, and thus an adhesive tape can be provided in which the adhesive force exhibits more excellent re-peelability over time, storage stability, etc. However, when it acts at a temperature above the softening point, the workability is reduced. Therefore, by making the product of the softening point (temperature) of the tackifying resin and the addition amount of the tackifying resin within the above range, the workability can be maintained at a certain level, and a bonding layer excellent in heat resistance can be formed. The value of the product (the temperature [°C] of the softening point of the tackifying resin × the addition amount of the tackifying resin (the addition amount of the tackifying resin when the triblock copolymer is 100 parts by mass)) is more preferably 5000 to 13000, and further preferably 6500 to 10000. In the case of containing two or more kinds of tackifying resins, the sum of the products of the temperature [°C] of the softening point of each tackifying resin and the addition amount of each tackifying resin (the addition amount of the tackifying resin when the triblock copolymer is 100 parts by mass) is preferably within the above range.

[0238] Specific examples of the tackifying resin include rosin-based tackifying resins, polymerized rosin-based tackifying resins, polymerized rosin ester-based tackifying resins, abietol-based tackifying resins, stabilized rosin ester-based tackifying resins, disproportionated rosin ester-based tackifying resins, hydrogenated rosin ester-based tackifying resins, terpene-based tackifying resins, terpene phenol-based tackifying resins, petroleum resin-based tackifying resins, (meth)acrylate-based tackifying resins, and the like. They can be used alone or in combination of two or more. Among them, the tackifying resin is preferably a polymerized rosin ester-based tackifying resin, an abietol-based tackifying resin, a disproportionated rosin ester-based tackifying resin, a hydrogenated rosin ester-based tackifying resin, a terpene phenol-based resin, or a (meth)acrylate-based resin.

[0239] As specific examples of the rosin-based tackifying resin, unmodified rosins (crude rosins) such as gum rosin, wood rosin, and tall oil rosin can be cited; modified rosins (hydrogenated rosin, disproportionated rosin, polymerized rosin, and other chemically modified rosins. The same shall apply hereinafter.) obtained by modifying these unmodified rosins through hydrogenation, disproportionation, polymerization, etc.; and various other rosin derivatives. Examples of the rosin derivatives include rosin esters such as substances obtained by esterifying unmodified rosin with alcohols (i.e., esterified products of rosin) and substances obtained by esterifying modified rosin with alcohols (i.e., esterified products of modified rosin); unsaturated fatty acid-modified rosins obtained by modifying unmodified rosin and modified rosin with unsaturated fatty acids; unsaturated fatty acid-modified rosin esters obtained by modifying rosin esters with unsaturated fatty acids; rosin alcohols obtained by reducing the carboxyl groups in unmodified rosin, modified rosin, unsaturated fatty acid-modified rosins, or unsaturated fatty acid-modified rosin esters; metal salts of rosins such as unmodified rosin, modified rosin, and various rosin derivatives (especially rosin esters); rosin phenol resins obtained by adding phenol to rosins (unmodified rosin, modified rosin, various rosin derivatives, etc.) using an acid catalyst and performing thermal polymerization. When an acrylic polymer is used as the base polymer, a rosin-based tackifying resin is preferably used. From the viewpoint of improving adhesion characteristics such as adhesion strength, it is more preferable to use two or more types of the rosin-based tackifying resin having different types, characteristics (such as softening point), etc. in combination.

[0240] Examples of the terpene-based tackifying resin include terpene resins such as α-pinene polymer, β-pinene polymer, and dipentene polymer; and modified terpene resins obtained by modifying these terpene resins (phenol modification, aromatic modification, hydrogenation modification, hydrocarbon modification, etc.). Examples of the modified terpene resin include terpene-modified phenolic resin, styrene-modified terpene resin, aromatic-modified terpene resin, and hydrogenated terpene resin. When an acrylic polymer is used as the base polymer, a terpene-based tackifying resin (such as terpene-modified phenolic resin) is preferably used. Especially from the viewpoint of improving adhesion characteristics such as adhesion strength, it is preferable to use one or more types of the terpene-based tackifying resin (such as terpene-modified phenolic resin) having different types, characteristics (such as softening point), etc. in combination.

[0241] Examples of the hydrocarbon-based tackifying resin include various hydrocarbon-based resins such as aliphatic hydrocarbon resin, aromatic hydrocarbon resin, aliphatic cyclic hydrocarbon resin, aliphatic-aromatic petroleum resin (such as styrene-olefin copolymer), aliphatic-alicyclic petroleum resin, hydrogenated hydrocarbon resin, coumarone resin, and coumarone-indene resin.

[0242] As the adhesive resin containing a triblock copolymer in the present embodiment, in terms of further improving the cohesion of the adhesive layer, an adhesive resin containing a crosslinking agent is preferably used.

[0243] As the crosslinking agent, there is no particular limitation, and it can be appropriately selected according to the purpose. For example, isocyanate-based crosslinking agents, epoxy-based crosslinking agents, metal chelate-based crosslinking agents, aziridine-based crosslinking agents, etc. can be cited. They can be used alone as one kind, or two or more kinds can be used in combination. Among them, the crosslinking agent is preferably a type of crosslinking agent that is mixed after the production of the acrylic polymer to carry out the crosslinking reaction, and more preferably an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent with high reactivity with the acrylic polymer.

[0244] As the isocyanate-based crosslinking agent, for example, toluene diisocyanate, triphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane-modified toluene diisocyanate, etc. can be cited. They can be used alone as one kind, or two or more kinds can be used in combination. Among them, toluene diisocyanate, their trimethylolpropane adducts, and triphenylmethane diisocyanate, which are 3-functional polyisocyanate-based compounds, are particularly preferred.

[0245] In this specification, as an index of the crosslinking degree, the insoluble component is measured after the adhesive layer is immersed in toluene for 24 hours, and the value of the gel fraction obtained is used. There is no particular limitation on the gel fraction of the adhesive layer, and it can be appropriately selected according to the purpose. It is preferably 0 to 50% by mass, more preferably 0 to 20% by mass; from the aspect of obtaining an adhesive layer with both good cohesiveness and adhesiveness, it is further preferably 0 to 10% by mass.

[0246] It should be noted that the gel fraction is the value measured by the following method. The adhesive composition containing the adhesive resin and, if necessary, additives is coated on the release sheet so that the dried thickness becomes 50 μm, dried at 100 °C for 3 minutes, and cured at 40 °C for 2 days. The obtained product is cut into a square with a side length of 50 mm and used as a sample. Next, the mass (G1) of the sample before toluene immersion is measured in advance, and the toluene-insoluble component of the sample after being immersed in the toluene solution at 23 °C for 24 hours is separated by filtering through a 300-mesh metal mesh, and the mass (G2) of the residue after drying at 110 °C for 1 hour is measured. The gel fraction is calculated according to the following mathematical formula (I). It should be noted that the mass (G3) of the conductive fine particles in the sample is calculated from the mass (G1) of the sample and the composition of the adhesive composition.

[0247] Gel fraction (% by mass) = (G2 - G3) / (G1 - G3) × 100 ··· Mathematical formula (I)

[0248] As other components in the adhesive layer of the present embodiment, there is no particular limitation, and they can be appropriately selected within the range that does not impair the characteristics of the adhesive tape. For example, polymer components other than the adhesive resin, crosslinking agents, anti-aging agents, ultraviolet absorbers, fillers, polymerization inhibitors, surface modifiers, antistatic agents, defoaming agents, viscosity regulators, light stabilizers, weather stabilizers, heat stabilizers, antioxidants, leveling agents, organic pigments, inorganic pigments, pigment dispersants, plasticizers, softeners, flame retardants, metal deactivators, silica beads, organic beads and other additives can be cited; inorganic fillers such as silica, alumina, titanium oxide, zirconium oxide, antimony pentoxide, etc. They can be used alone or in combination of two or more.

[0249] The content of other components in the adhesive layer of the present embodiment can be appropriately selected within the range that does not impair the characteristics of the adhesive tape.

[0250] The adhesive layer of the adhesive tape of the present embodiment preferably contains a filler, a tackifying resin, and an adhesive resin mainly composed of a triblock copolymer represented by the general formula (1).

[0251] In the present embodiment, the adhesive composition as the precursor of the adhesive layer preferably contains a filler. By making the adhesive composition as the precursor of the adhesive layer contain this filler, the filler can be exposed from the adhesive layer when the adhesive tape is stretched, whereby the bonding area between the adhesive layer and the adherend becomes smaller. Therefore, even when the stretching direction of the adhesive tape is at a relatively large angle with respect to the attachment surface of the adherend (hereinafter, sometimes also referred to as the "bonding surface"), for example, the vertical direction (sometimes also referred to as the "90° direction"), and further, even when it is stretched at a fast speed, the adhesive tape can be peeled off more simply and quickly.

[0252] As the type of the filler, there is no particular limitation, and it can be appropriately selected within the range that does not impair the effects of the present invention. It can be an inorganic filler or an organic filler. They can be used alone or in combination of two or more.

[0253] Specific examples of the inorganic filler include aluminum hydroxide, magnesium hydroxide, aluminum oxide, silicon oxide, magnesium oxide, zinc oxide, titanium oxide, zirconium oxide, iron oxide, silicon carbide, boron nitride, aluminum nitride, titanium nitride, silicon nitride, titanium boride, carbon, nickel, copper, aluminum, titanium, gold, silver, zirconium hydroxide, basic magnesium carbonate, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, tin oxide, tin oxide hydrate, borax, zinc borate, zinc metaborate, barium metaborate, zinc carbonate, magnesium-calcium carbonate, calcium carbonate, barium carbonate, molybdenum oxide, antimony oxide, red phosphorus, mica, clay, kaolin, talc, zeolite, wollastonite, montmorillonite, silicon dioxide (quartz, fumed silica, precipitated silica, anhydrous silicic acid, fused silica, crystalline silica, ultrafine amorphous silica, etc.), potassium titanate, magnesium sulfate, sepiolite, vermiculite, aluminum borate, barium sulfate, barium titanate, zirconium oxide, cerium, tin, indium, carbon, sulfur, tellurium (Japanese: テリウム), cobalt, molybdenum, strontium, chromium, barium, lead, tin oxide, indium oxide, diamond, magnesium, platinum, zinc, manganese, stainless steel, etc. Among them, aluminum hydroxide, nickel, etc. are preferred.

[0254] In addition, in order to improve the dispersibility in the adhesive resin, the inorganic filler may also be an inorganic filler that has been subjected to surface treatment such as silane coupling treatment or stearic acid treatment.

[0255] Specific examples of the organic filler include polystyrene-based fillers, benzoguanamine-based fillers, polyethylene-based fillers, polypropylene-based fillers, silicone-based fillers, urea-formalin-based fillers, styrene / methacrylic acid copolymers, fluorine-based fillers, acrylic-based fillers, polycarbonate-based fillers, polyurethane-based fillers, polyamide-based fillers, epoxy resin-based fillers, thermosetting resin-based hollow fillers, etc.

[0256] It should be noted that among the organic fillers, as the silicone-based filler, specifically, silicone rubber particles formed by three-dimensionally crosslinking linear organopolysiloxane (refer to Japanese Patent Laid-Open No. 63-77942, Japanese Patent Laid-Open No. 3-93834, Japanese Patent Laid-Open No. 04-198324), substances obtained by pulverizing silicone rubber (refer to U.S. Patent No. 3843601, Japanese Patent Laid-Open No. 62-270660, Japanese Patent Laid-Open No. 59-96122), etc. In addition, silicone composite particles having a structure in which the surface of the silicone rubber particles obtained by the above method is coated with a silicone resin as a cured product of polyorganosilsesquioxane can also be used. The cured product of polyorganosilsesquioxane has a three-dimensionally crosslinked network structure represented by (R’SiO 3 / 2 ) n (R’ represents a substituted or unsubstituted monovalent hydrocarbon group) (refer to Japanese Patent Laid-Open No. 7-196815).

[0257] As the silicone particles, silicone particles commercially available from Dow Corning Toray Silicone Co., Ltd. under the above-mentioned trade names such as TREFIL E-500, TREFIL E-600, TREFIL E-601, TREFIL E-850, etc., and silicone particles commercially available from Shin-Etsu Chemical Co., Ltd. such as KMP-600, KMP-601, KMP-602, KMP-605, etc. can be used.

[0258] In addition, as other silicone-based fillers, acrylic-modified silicone particles can be used. As the acrylic-modified silicone particles, an emulsion graft polymer of a polyorganosiloxane represented by the following general formula (C), an acrylic ester monomer and / or a methacrylic ester monomer, and a functional group-containing monomer copolymerizable therewith can be cited.

[0259] [Chemical Formula 11]

[0260]

[0261] (In the above general formula (C), R 5 and R 6 each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, X 1 , X 2 , X 3 , X 4 , X 5 and X 6 each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a hydroxyl group, Y 1 and Y 2 each independently represent a group represented by X 1 or -[O-Si(X 7 )(X 8 )] c -X 9 , X 7 , X 8 and X 9 each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a hydroxyl group, X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 and X 9 as well as Y 1 and Y2 At least two of the groups are hydroxyl groups, and a, b, and c are each independently a positive number satisfying 0 ≤ a ≤ 1000, a positive number satisfying 100 ≤ b ≤ 10000, and a positive number satisfying 1 ≤ c ≤ 1000.)

[0262] In general formula (C), R 5 or R 6 The alkyl group having 1 to 20 carbon atoms represented by may be linear, branched, or cyclic. Specifically, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, cyclopentyl, cyclohexyl, cycloheptyl, etc. can be mentioned. These alkyl groups may be substituted with a halogen atom, acryloyloxy, methacryloyloxy, carboxyl group, alkoxy group, alkenyloxy group, amino group, alkyl group, alkoxy group, or an amino group substituted with (meth)acryloyloxy.)

[0263] As R 5 or R 6 Examples of the aryl group having 6 to 20 carbon atoms represented by include phenyl, tolyl, naphthyl, etc. As R 5 or R 6 , it is preferably methyl.)

[0264] In general formula (C), as X 1 ~X 9 Examples of the alkyl group having 1 to 20 carbon atoms and the aryl group having 6 to 20 carbon atoms represented by include the same groups as the alkyl groups and aryl groups exemplified in R 5 or R 6 . Examples of the alkoxy group having 1 to 20 carbon atoms represented by X 1 ~X 9 include methoxy, ethoxy, propoxy, butoxy, hexyloxy, heptyloxy, octyloxy, decyloxy, tetradecyloxy, etc.)

[0265] In general formula (C), a, b, and c are positive numbers satisfying 0 ≤ a ≤ 1000, positive numbers satisfying 100 ≤ b ≤ 10000, and positive numbers satisfying 1 ≤ c ≤ 1000. a is preferably a positive number from 0 to 200. If a is greater than 1000, the strength of the obtained coating film becomes insufficient. b is preferably a positive number from 1000 to 5000. If b is less than 100, the flexibility of the coating film is insufficient, and if it is greater than 10000, it is difficult to form a solid shape like particles. c is preferably a positive number from 1 to 200.)

[0266] In addition, from the aspect of crosslinkability, the polyorganosiloxane represented by general formula (C) has at least 2, preferably 2 to 4, hydroxyl groups in one molecule, and preferably has such hydroxyl groups at both ends of the molecular chain.)

[0267] Examples of the acrylic ester monomer or methacrylic ester monomer include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, cyclohexyl methacrylate, and the like.

[0268] Examples of the functional group-containing monomer that can copolymerize with the acrylic ester monomer and / or methacrylic ester monomer include monomers having an unsaturated bond containing a carboxyl group, an amide group, a hydroxyl group, a vinyl group, an allyl group, and the like.

[0269] Preferably, 10 to 100 parts by mass of the acrylic ester monomer and / or methacrylic ester monomer and 0.01 to 20 parts by mass of the functional group-containing monomer copolymerizable therewith are mixed with 100 parts by mass of the polyorganosiloxane represented by the above general formula (4), and emulsion graft polymerization is carried out to obtain the acrylic-modified organosilicon powder. The conditions in the emulsion graft polymerization are not particularly limited. As the initiator used in the polymerization, a known radical initiator commonly used for acrylic polymers can be used. In addition, known anionic surfactants and nonionic surfactants can also be used as the emulsifier.

[0270] The acrylic-modified organosilicon particles are granulated by the methods listed below to be made into a powder. That is, examples include spray dryer drying, fluidized bed drying, etc. However, considering productivity, a spray dryer is preferred. Powderization is preferably carried out by heat drying, and it is preferably carried out at 80 to 150 °C.

[0271] As the acrylic-modified organosilicon particles, for example, commercially available products such as CHALINE R-170S and CHALINER-200 (both are manufactured by Nissin Chemical Industry Co., Ltd.) can also be used.

[0272] The shape of the filler in this embodiment is not particularly limited and can be appropriately selected according to the purpose. It can be a regular shape or an irregular shape. Specific examples of the shape of the filler include polygonal shapes, cubic shapes, elliptical shapes, spherical shapes, needle-like shapes, flat plate shapes, scaly shapes, etc. These shaped fillers can be used alone or in combination of two or more. In addition, it can also be a substance formed by the aggregation of these shaped fillers. Among them, as the shape of the filler, an elliptical shape, a spherical shape, and a polygonal shape are preferred. If the filler shape is an elliptical shape, a spherical shape, a polygonal shape, etc., when the adhesive tape stretches, the sliding of the adhesive layer relative to the adherend becomes good, and the adhesive tape can be peeled off more simply and quickly.

[0273] The particle size distribution (D90 / D10) of the filler in the present embodiment is not particularly limited and can be appropriately selected according to the purpose. It is preferably 2.5 to 20; from the aspect of impact resistance, it is more preferably 2.5 to 15, and further preferably 2.5 to 5. If the particle size distribution (D90 / D10) of the filler is within the preferred range, the adhesive tape can be peeled off more simply and rapidly, and it is not easily broken even when the thickness of the substrate of the adhesive tape is thin, and the impact resistance, shear adhesion, and cleavage adhesion are excellent. On the other hand, if the particle size distribution (D90 / D10) of the filler is less than 2.5, the elongation peelability may be impaired, and if it exceeds 20, the adhesive properties such as impact resistance, shear adhesion, and cleavage adhesion may be impaired.

[0274] The particle size distribution (D90 / D10) of the filler in the present embodiment is obtained, for example, by measuring the average particle size of the filler using a measuring machine (Microtrac) based on the laser diffraction scattering method and converting it into a particle size distribution.

[0275] The average particle size of the filler in the present embodiment is 0.1 to 40 μm, preferably 5 to 40 μm, more preferably 10 to 35 μm, further preferably 10 to 30 μm, and particularly preferably 10 to 25 μm. If the average particle size of the filler is within the preferred range, the adhesive tape can be peeled off more simply and rapidly, and it is not easily broken even when the thickness of the substrate of the adhesive tape is thin, and the impact resistance, shear adhesion, and cleavage adhesion are excellent. On the other hand, if the particle size of the filler is less than 0.1 μm, the elongation peelability may be impaired; if it exceeds 40 μm, the adhesive properties such as impact resistance, shear adhesion, and cleavage adhesion may be impaired.

[0276] It should be noted that the average particle size of the filler in the present embodiment refers to the volume average particle size and can be measured, for example, by using a measuring machine (Microtrac) based on the laser diffraction scattering method.

[0277] It should be noted that when using the silicone rubber particles or silicone composite particles as the filler in the present embodiment, the average particle size of the silicone rubber particles and silicone composite particles is preferably 0.1 to 40 μm, and more preferably 5 to 40 μm. If the average particle size is less than 0.1 μm, there is a tendency for the effect of reducing the adhesive area caused by the filler during the elongation of the adhesive tape to decrease; in addition, if it is greater than 40 μm, there is a tendency for the adhesive strength of the adhesive tape to decrease.

[0278] In addition, when using the acrylic-modified silicone particles as the filler in the present embodiment, the average particle diameter of the acrylic-modified silicone particles is preferably 0.1 to 40 μm, more preferably 5 to 40 μm, further preferably 5 to 30 μm, and even more preferably 10 to 25 μm. If the average particle diameter is less than 0.1 μm, there is a tendency for the effect of reducing the bonding area caused by the filler during the elongation of the adhesive tape to decrease; in addition, if it is greater than 40 μm, there is a tendency for the adhesive strength of the adhesive tape to decrease.

[0279] There is no particular limitation on the ratio of the average particle diameter of the filler in the present embodiment to the average thickness of the adhesive layer, and it can be appropriately selected according to the purpose. The ratio of the average particle diameter of the filler, expressed as [volume average particle diameter of the filler / average thickness of the adhesive layer], to the average thickness of the adhesive layer is preferably 5 / 100 or more, more preferably 5 / 100 to 95 / 100, further preferably 10 / 100 to 75 / 100, and particularly preferably 20 / 100 to 60 / 100. If the ratio is 5 / 100 or more, the adhesive tape can be peeled off more simply and quickly, and it is not easily broken even when the thickness of the base material of the adhesive tape is thin. In addition, from the aspect that the adhesive properties such as impact resistance, shear adhesive strength, and cleavage adhesive strength are also more excellent, it is advantageous that the ratio is 95 / 100 or less.

[0280] Relative to 100% by mass of the adhesive resin, the content of the filler in the adhesive layer of the present embodiment is preferably 0 to 300% by mass, further preferably 1 to 100% by mass, preferably 10 to 60% by mass, and more preferably 20 to 50% by mass. By making the content of the filler relative to 100% by mass of the adhesive resin 1% by mass or more, the adhesive tape can be peeled off more simply and quickly. In addition, by making the content of the filler relative to 100% by mass of the adhesive resin 100% by mass or less, it is possible to prevent the adhesive composition from remaining on the adherend, the impact resistance from deteriorating, or the shear adhesive strength and cleavage adhesive strength from weakening.

[0281] The content of the filler in the adhesive layer of the present embodiment can be appropriately prepared when preparing the adhesive composition as the precursor of the adhesive layer.

[0282] It should be noted that when using the silicone rubber particles or silicone composite particles as the filler, the content of the silicone rubber particles or silicone composite particles is preferably 15 to 35% by mass relative to 100% by mass of the adhesive layer.

[0283] In addition, when using the acrylic-modified silicone particles as the filler, the content of the acrylic-modified silicone particles is preferably 1.0 to 20% by mass relative to 100% by mass of the adhesive layer.

[0284] The ratio of the volume of the filler in this embodiment to the volume of the entire adhesive layer is preferably 4 to 40%, more preferably 5 to 30%, still more preferably 5 to 20%, and most preferably 5 to 15%. By making the volume ratio of the filler 4% or more, the adhesive tape can be peeled off more simply and quickly. In addition, by making the volume ratio of the filler 40% or less, it is possible to prevent the adhesive layer from remaining on the adherend, the impact resistance from deteriorating, and the shear adhesion and cleavage adhesion from weakening.

[0285] It should be noted that the volume ratio of the filler to the adhesive layer can be calculated by the following mathematical formulas (1) to (3).

[0286] Mass A (g) of the adhesive resin * 1 / Density A (g / cm 1 ) of the adhesive resin * 3 = Volume A (cm 3 ) of the adhesive resin * 1 ··· Mathematical formula (1)

[0287] Mass B (g) of the filler / Density B (g / cm 3 ) of the filler = Volume B (cm 3 ) of the filler ··· Mathematical formula (2)

[0288] Volume B (cm 3 ) of the filler / (Volume A (cm 1 ) of the adhesive resin * 3 + Volume B (cm 3 )) × 100 = Volume ratio (%) of the filler ··· Mathematical formula (3)

[0289] It should be noted that in the above mathematical formulas (1) and (3), the adhesive resin * 1 shown may contain other components described later. The density is the value measured according to JIS Z 8804.

[0290] The adhesive tape of this embodiment may also be appropriately provided with one layer or two or more other layers according to the purpose. Examples of such other layers include a primer layer, an antistatic layer, a non-combustible layer, a decorative layer, a conductive layer, a heat conductive layer, and a release layer.

[0291] As long as the adhesive tape of this embodiment has a base material layer and an adhesive layer on at least one surface of the base material layer, its shape and size are not particularly limited. For example, it includes an adhesive tape having a shape and size suitable for attaching to a specified adherend (for example, an adhesive tape in the state after punching), and a sheet-like long adhesive tape (for example, an adhesive tape before being processed into a specific shape). In addition, for the adhesive tape of this embodiment, for example, in order to attach to or peel off from the adherend, a non-adhesive handle area can be arbitrarily provided.

[0292] The (average) thickness of the adhesive tape is not particularly limited and can be appropriately selected according to the (average) thickness of the adhesive layer and the base material layer, etc. It is preferably 20 to 1000 μm, more preferably 30 to 600 μm, further preferably 50 to 400 μm, and particularly preferably 100 to 250 μm.

[0293] It should be noted that in this specification, the "thickness of the adhesive tape" means: the adhesive tape is cut 5 times in the width direction at intervals of 100 mm in the length direction, and the thickness of the adhesive layer is measured 5 times at intervals of 100 mm in the width direction at each cut surface using a TH-104 paper / membrane thickness measuring machine (manufactured by TESTER SANGYO Co., Ltd.), and the average value obtained by averaging a total of 25 thicknesses.

[0294] The hardness of the adhesive tape (Shore A hardness) is not particularly limited and can be appropriately selected according to the purpose. It is preferably 15 to 90, more preferably 20 to 85, and further preferably 50 to 85. If the Shore A hardness of the adhesive tape is within the above preferred range, the re-peeling operation by stretching and peeling the adhesive tape becomes easy. On the other hand, if the Shore A hardness is less than 10, the adhesive tape may break when the adhesive tape is stretched and peeled; if it exceeds 90, when the adhesive tape is stretched and then peeled, the stress for stretching becomes too high, and sometimes it cannot be peeled again.

[0295] The rubber hardness of the adhesive tape is the Shore A hardness, which means the value measured in accordance with JIS K 6253 using a hardness tester (spring-type rubber hardness tester) (model: GS-719G, manufactured by TECLOCK Co., Ltd.).

[0296] The 25% elongation stress of the adhesive tape is preferably 0.15 to 82 MPa, more preferably 0.16 to 10 MPa, further preferably 0.17 to 5 MPa, and most preferably 0.18 to 4.5 MPa. If the 25% elongation stress of the adhesive tape is 0.15 MPa to 82 MPa, an adhesive strength suitable for an adhesive tape can be obtained, and it can be peeled relatively easily even during elongation peeling. On the other hand, if the 25% elongation stress of the adhesive tape is less than 0.15 MPa, the adhesive tape may peel when a load in the shear direction of the adhesive tape is generated while fixing hard adherends to each other. In addition, if the 25% elongation stress of the adhesive tape exceeds 82 MPa, when peeling the adhesive tape, there is a tendency for the force required to stretch the adhesive tape to become too large.

[0297] The 25% elongation stress of the adhesive tape means: The adhesive tape is punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and under the conditions of a measurement atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched in the length direction at a tensile speed of 500 mm / minute, and the stress value measured when the elongation is 25% is obtained.

[0298] There is no particular limitation on the breaking stress of the adhesive tape, and it can be appropriately selected according to the purpose. It is preferably 10 to 100.0 MPa, more preferably 15 to 90.0 MPa, further preferably 30 to 90.0 MPa, and particularly preferably 40 to 90.0 MPa. If the breaking stress of the adhesive tape is within the above-mentioned preferred range, even when the adhesive tape is rapidly stretched and peeled off, the breakage of the adhesive tape can be suppressed, and the load for stretching the adhesive tape will not become excessive. Therefore, the re-peeling operation by stretching and peeling becomes easy. On the other hand, if the breaking stress of the adhesive tape is less than 10 MPa, the adhesive tape sometimes breaks when it is rapidly stretched and peeled off; if it exceeds 100.0 MPa, in the case where the adhesive tape is to be stretched for re-peeling, sometimes it cannot be sufficiently stretched and cannot be re-peeled. It should be noted that the force required to stretch the adhesive tape and deform it also depends on the thickness of the adhesive tape. For example, in the case where an adhesive tape with a thick thickness and a high breaking stress is to be stretched for re-peeling, sometimes it cannot be sufficiently stretched and cannot be re-peeled.

[0299] The breaking stress of the adhesive tape means: The adhesive tape is punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and under the conditions of a measurement atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched in the length direction at a tensile speed of 500 mm / minute, and the stress value measured when breakage occurs is obtained.

[0300] The breaking elongation of the adhesive tape is not particularly limited and can be appropriately selected according to the purpose. It is preferably 400 to 2000%, more preferably 500 to 1800%, and still more preferably 600 to 1200%. If the breaking elongation of the adhesive tape is 400% or more, then even when the adhesive tape is firmly adhered to the adherend, when the adhesive tape is re-peeled, the stress for stretching in the horizontal direction to the vertical direction with respect to the adhering surface of the adherend will not become too large. Even during tensile peeling, the adhesive tape will not over-elongate and can be easily peeled. In addition, if the breaking elongation is 2000% or less, when the adhesive tape is re-peeled, the stretching distance in the horizontal direction to the vertical direction with respect to the adhering surface of the adherend will not become too long, and the operation can be carried out in a small space. On the other hand, if the breaking elongation is less than 500%, when the adhesive tape is re-peeled, it may sometimes break and cannot be peeled when stretched in the horizontal direction to the vertical direction along the adhering surface of the adherend; if it exceeds 1300%, when the adhesive tape is re-peeled, the stretching distance in the horizontal direction to the vertical direction with respect to the adhering surface of the adherend may sometimes become too long, so the workability deteriorates.

[0301] The breaking elongation of the adhesive tape means: The adhesive tape is punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm, and under the conditions of a measurement atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it is stretched in the length direction at a stretching speed of 500 mm / minute, and the tensile elongation measured when it breaks.

[0302] The adhesive tape also has excellent impact resistance. The impact resistance can be confirmed, for example, by the method described in the "Evaluation of Impact Resistance" in the following Examples section. In the evaluation of impact resistance, as the height of the impact core that causes the peeling or damage of the adhesive tape, it can be appropriately selected within the range that does not impair the effects of the present invention, preferably 30 cm or more, more preferably 40 cm or more, still more preferably 50 cm or more, and particularly preferably 60 cm or more. If the height is less than 30 cm, there is a tendency that sufficient impact resistance cannot be obtained.

[0303] The storage modulus G'(23°C) of the adhesive tape is preferably 1.0×10 4 ~1.0×10 8 Pa, more preferably 5.0×10 4 ~5.0×10 7 Pa, still more preferably 1.0×10 5 ~1.0×10 7 Pa, even more preferably 3.0×10 5 ~8.0×10 6Pa. By making the breaking point stress of the adhesive tape within the above range, it is easy to follow the deformation of the adherend, etc., and it is easy to obtain excellent adhesive strength. It can also ensure the dimensional stability of the adhesive tape, so that suitable adhesion workability can be obtained. As described above, for the adhesive tape of the present invention, it is also conceivable that the adherend is a hard and large-area adherend such as metal or plastic. Generally speaking, the larger the area of the adherend, the more difficult it is to suppress deformation during forming. If the adhesive tape has the above-mentioned storage modulus range, the deformation of the adherend as described above can be followed by the adhesive tape, and suitable adhesive force can be obtained.

[0304] The 180° peel adhesive force of the adhesive tape is not particularly limited and can be appropriately selected according to the purpose. It is preferably 3 N / 20 mm to 50 N / 20 mm, more preferably 10 N / 20 mm to 50 N / 20 mm, and further preferably 15 N / 20 mm to 45 N / 20 mm. If the 180° peel adhesive force is within the above preferred range, there will be no peeling or displacement from the adherend and it will have an appropriate adhesive force, and when the adhesive tape is stretched in the horizontal direction to the vertical direction with respect to the adhesion surface of the adherend and then peeled again, it can be easily peeled.

[0305] The 180° peel adhesive force of the adhesive tape in this specification refers to the value measured in accordance with JIS Z 0237.

[0306] The shear adhesive force of the adhesive tape of this embodiment is preferably 1 MPa or more, preferably in the range of 0.7 to 4.0 MPa, more preferably in the range of 1.0 to 4.0 MPa, and further preferably in the range of 1.5 to 4.0 MPa. If the shear adhesive force is within the above preferred range, the effect of easily achieving both high load holding force and adhesiveness can be realized. The shear adhesive force of the adhesive tape refers to the value measured by the method described in the following examples.

[0307] In this embodiment, the manufacturing method of the adhesive tape is not particularly limited and can be appropriately selected from known methods. In the manufacturing method of the adhesive tape of this embodiment, it preferably includes an adhesive layer forming step, a base material layer forming step, and a laminating step, and further includes other layer forming steps as needed. In addition, it can also be manufactured by a multi-layer simultaneous forming step of simultaneously performing the adhesive layer forming step and the base material layer forming step.

[0308] As long as the adhesive layer forming step can form an adhesive layer, it is not particularly limited and can be appropriately selected according to the purpose. For example, methods such as forming an adhesive layer on the surface of a release sheet by a hot pressing method, a casting method based on extrusion molding, a uniaxial stretching method, a successive secondary stretching method, a simultaneous biaxial stretching method, a blow molding method, a tube method, a calendering method, a solution method, etc. can be cited. Among them, the casting method based on extrusion molding and the solution method are preferred.

[0309] As the release sheet, there is no particular limitation, and it can be appropriately selected according to the purpose. For example, papers such as kraft paper, cellophane, and chemical pulp paper can be cited; resin films such as polyethylene, polypropylene (biaxially stretched polypropylene (OPP), uniaxially stretched polypropylene (CPP)), and polyethylene terephthalate (PET); laminated paper formed by laminating the paper and the resin film; materials obtained by performing a caulking treatment on the paper with clay, polyvinyl alcohol, etc. and then performing a release treatment with a silicone-based resin or the like on one or both sides. They can be used alone or in combination of two or more.

[0310] The substrate layer forming process has no particular limitation as long as it can form the substrate layer, and it can be appropriately selected according to the purpose. For example, hot pressing, casting based on extrusion molding, uniaxial stretching, successive secondary stretching, simultaneous biaxial stretching, inflation, tube method, calendering, solution method, etc. can be cited. These methods can be used alone or in combination of two or more. Among them, from the aspect of imparting suitable flexibility and stretchability to the substrate layer, casting based on extrusion molding, inflation, tube method, calendering, and solution method are preferred.

[0311] It should be noted that for the purpose of further improving the adhesion to the adhesive layer, the substrate layer can be surface-treated.

[0312] As the surface treatment method, there is no particular limitation, and it can be appropriately selected from known methods within the range that does not damage the characteristics of the adhesive tape. For example, sandblasting, surface grinding / friction, corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone treatment, ultraviolet irradiation treatment, oxidation treatment, etc. can be cited.

[0313] The lamination process is a process of laminating the substrate layer and the adhesive layer. As the method of laminating the substrate layer and the adhesive layer, there is no particular limitation, and it can be appropriately selected from known methods. For example, a method of laminating by pressing the adhesive layer and the substrate layer in a state where the adhesive layer adheres to the release sheet formed in the adhesive layer forming process can be cited.

[0314] The adhesive tape of the present invention can be suitably used for fixing between metal plates constituting relatively large electronic instruments such as thin TVs, home appliances, and office automation equipment; fixing between exterior components and a housing; fixing rigid components such as exterior components and batteries to relatively small electronic devices such as portable electronic terminals, cameras, and personal computers, etc. in various industrial fields, temporary fixing of the components, and uses such as labels for displaying product information.

[0315] The embodiments of the present invention have been described above, but the adhesive tape of the present invention is not limited to the above examples and can be appropriately modified.

[0316] Examples

[0317] Hereinafter, the content of the present invention will be described in detail using examples, but the scope of the present invention is not limited to the following examples. The measurement and evaluation of the substrate layer, adhesive layer, and adhesive tape obtained in each example and comparative example were carried out based on the following methods.

[0318] (1) Measurement of breaking stress and elongation at break of the substrate layer

[0319] Each substrate layer was punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm. Under the conditions of a measurement atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it was stretched in the longitudinal direction at a stretching speed of 500 mm / min to measure the breaking stress and elongation at break of the substrate layer. The results are shown in Table 1 below.

[0320] (2) Measurement of 50% modulus of the substrate layer

[0321] Each substrate layer was punched into a dumbbell shape with a gauge length of 20 mm and a width of 5 mm. Under the conditions of a measurement atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Co., Ltd.), it was stretched in the longitudinal direction at a stretching speed of 500 mm / min to measure the stress value when the substrate layer elongated by 50%.

[0322] (3) Measurement of the thickness of the substrate layer and the adhesive layer

[0323] The substrate layer and the adhesive layer were cut 5 times in the width direction at intervals of 100 mm in the length direction, and the thickness at 5 locations was measured at intervals of 100 mm in the width direction in each cut surface using a TH-104 paper and film thickness measuring machine (manufactured by TESTER SANGYO Co., Ltd.). The value obtained by averaging the thicknesses of these 25 points was used as the thickness of the substrate layer and the adhesive layer.

[0324] (4) Measurement of the average particle size of the filler

[0325] The average particle size (primary particle size) of the filler was measured using a measuring machine (Microtrac) that utilizes the laser diffraction scattering method.

[0326] (5) Evaluation of 180° peel adhesion

[0327] The 180° peel adhesion force is measured in accordance with JIS Z 0237. Specifically, each adhesive tape is cut into a size of 150 mm in length and 20 mm in width, and a PET film with a thickness of 25 μm is laminated on one surface of the adhesive tape. Then, the other surface of the adhesive tape is attached to a stainless steel plate (100 mm in length, 30 mm in width, and 3 mm in thickness) under the conditions of an atmosphere of 23°C and 50% RH. After applying a load of 2 kg to the laminate structure of the adhesive tape and the stainless steel plate and reciprocally pressing it once with a roller to make it adhere, it is left standing for 1 hour under the conditions of an atmosphere of 23°C and 50% RH to obtain a test piece. Then, under the conditions of an atmosphere of 23°C and 50% RH, using a Tensilon tensile testing machine (model: RTF-1210, manufactured by A&D Company, Limited), the adhesive tape on the test piece is stretched in the 180° direction (horizontal direction) at a stretching speed of 300 mm / min to measure the 180° peel adhesion force of the adhesive tape.

[0328] (6) Evaluation of shear adhesion force

[0329] The manufactured adhesive tape is cut into 25 mm in width and 25 mm in length, and it is attached to the surface of a clean and smooth stainless steel plate 1 (hairline polished with 360 grit waterproof abrasive paper) under an atmosphere of 23°C and 50% RH so that the attachment area is 25 mm × 25 mm; its reverse side is attached to the surface of a clean and smooth stainless steel plate 2 (hairline polished with 360 grit waterproof abrasive paper) under an atmosphere of 23°C and 50% RH so that the attachment area is 25 mm × 25 mm, and then it is reciprocally pressed once with a 5 kg roller to make them adhere; it is left standing in an environment of 23°C for 24 hours to produce a test piece. Then, with the stainless steel plate 1 constituting the test piece fixed, using a Tensilon tensile testing machine, under an atmosphere of 23°C and 50% RH, the stainless steel plate 2 is stretched in the shear direction of the adhesive tape at a speed of 300 mm / min to measure the shear adhesion force.

[0330] (7) Evaluation of high load holding force

[0331] On a SUS304 steel plate with a width of 25 mm × a width of 80 mm specified in JIS Z0237, one surface of each adhesive tape cut into a width of 25 mm × a length of 25 mm is adhered by reciprocating pressing once at a speed of 300 mm per minute with a roller weighing 5 kg at room temperature, and then it is left for 30 minutes under the conditions of 23°C. Then, the reverse side of the test piece is adhered to a SUS304 steel plate with a width of 25 mm × a width of 80 mm specified in JIS Z0237 by reciprocating pressing once at a speed of 300 mm per minute with a roller weighing 5 kg at room temperature. Next, it is left in an atmosphere of 40°C for 30 minutes. Then, a 5 kg weight is installed on the handle part of the test piece, and it is allowed to hang down to start the test, and the time until it falls is measured at 23°C and 50% RH. For the high load holding force, the case where the falling time is 120 minutes or more is regarded as qualified. In addition, the case where the falling time is less than 120 minutes is regarded as unqualified.

[0332] (8) Re-peelability evaluation

[0333] For the evaluation of re-peelability, a re-peelability evaluation 1 (180° direction) of stretching the handle part provided at one end in the length direction of the adhesive tape along the length direction and a re-peelability evaluation 2 (90° direction) of stretching the adhesive tape in a direction 90° relative to the length direction are carried out. The following is a detailed description.

[0334] (8-1) Re-peelability evaluation 1 (180° direction)

[0335] (Initial re-peelability in re-peelability evaluation 1 (180° direction))

[0336] When attaching the adhesive tape with a width of 10 mm × a total length of 60 mm to a clean and smooth-surfaced aluminum plate, in order to use the part with a width of 10 mm × a length of 10 mm in the adhesive tape as the handle, it is attached in a state where the handle protrudes from the aluminum plate. Then, the reverse side of the adhesive tape is also attached to a clean and smooth-surfaced acrylic plate, and it is reciprocally pressed once with a roller while applying a 2 kg load, and it is used as a test piece. After attachment, it is left in an atmosphere of 23°C and 50% RH for 60 minutes, and at 23°C and 50% RH, the handle part of the adhesive tape is stretched by hand along the length direction of the adhesive tape at a speed of 300 mm / min.

[0337] In 10 test times, the fracture of the adhesive tape and the remaining degree of the adhesive on the adherend after the adhesive tape is peeled off are visually evaluated according to the following criteria.

[0338] ◎: In all 10 times, there is no fracture of the adhesive tape and no adhesive residue, and it is peeled off cleanly.

[0339] ○: The tape was peeled off 10 times without breakage, but there was adhesive residue in more than 1 case.

[0340] △: The tape did not break and there was no adhesive residue in 6 - 9 times, and it was peeled off cleanly.

[0341] ×: The tape broke or there was adhesive residue, or the tape could not be stretched for peeling in 5 - 10 times.

[0342] (Peelability over time in Peelability Evaluation 1 (180° direction))

[0343] When attaching the adhesive tape with a width of 10 mm and a total length of 60 mm to a clean and smooth - surfaced aluminum plate, taking the part of the adhesive tape with a width of 10 mm and a length of 10 mm as a handle, attach it in a state where the handle protrudes from the aluminum plate. Then, attach the reverse side of the adhesive tape to a clean and smooth - surfaced acrylic plate, apply a 2 - kg load while reciprocatingly pressing it with a roller once to make it a test piece. After attachment, place it in an atmosphere of 23°C and 50% RH for 3 days. At 23°C and 50% RH, stretch the handle part of the adhesive tape by hand along the length direction of the adhesive tape at a speed of 300 mm / min.

[0344] In 10 test times, visually evaluate the breakage of the adhesive tape and the residual degree of the adhesive on the adherend after the adhesive tape is peeled off according to the following criteria.

[0345] ◎: The adhesive tape did not break and there was no adhesive residue in 10 times, and it was peeled off cleanly.

[0346] ○: The tape was peeled off 10 times without breakage, but there was adhesive residue in more than 1 case.

[0347] △: The tape did not break and there was no adhesive residue in 6 - 9 times, and it was peeled off cleanly.

[0348] ×: The tape broke or there was adhesive residue, or the tape could not be stretched for peeling in 5 - 10 times.

[0349] (8 - 2) Peelability 2 (90° direction)

[0350] (Initial peelability in Peelability 2 (90° direction))

[0351] When attaching the adhesive tape with a width of 10 mm and a total length of 60 mm to a clean and smooth aluminum plate surface, a 10 mm wide by 10 mm long portion of the adhesive tape is used as a handle, and it is attached in a state where the handle protrudes from the aluminum plate. Then, the reverse side of the adhesive tape is also attached to a clean and smooth acrylic plate, and while applying a 2 kg load, it is reciprocally pressed once with a roller to make it a test piece. After attachment, it is placed in an atmosphere of 23°C and 50% RH for 60 minutes, and at 23°C and 50% RH, the handle portion is manually stretched at a speed of approximately 300 mm / min in a direction perpendicular to the length direction of the adhesive tape.

[0352] In 10 test runs, the breakage of the adhesive tape and the remaining degree of the adhesive on the adherend after the adhesive tape is peeled off are visually evaluated according to the following criteria.

[0353] ◎: In all 10 cases, there is no breakage of the adhesive tape and no remaining adhesive, and it is peeled off cleanly.

[0354] ○: In all 10 cases, it is peeled off without breakage of the adhesive tape, but there is remaining adhesive in more than 1 case.

[0355] △: In 6 - 9 cases, there is no breakage of the adhesive tape and no remaining adhesive, and it is peeled off cleanly.

[0356] ×: In 5 - 10 cases, there is breakage of the adhesive tape or remaining adhesive, or the adhesive tape cannot be stretched and peeled off.

[0357] (Time-dependent re-peelability in re-peelability 2 (90° direction))

[0358] When attaching the adhesive tape with a width of 10 mm and a total length of 60 mm to a clean and smooth aluminum plate surface, a 10 mm wide by 10 mm long portion of the adhesive tape is used as a handle, and it is attached in a state where the handle protrudes from the aluminum plate. Then, the reverse side of the adhesive tape is also attached to a clean and smooth acrylic plate, and while applying a 2 kg load, it is reciprocally pressed once with a roller to make it a test piece. After attachment, it is placed in an atmosphere of 23°C and 50% RH for 3 days, and at 23°C and 50% RH, the handle portion is manually stretched at a speed of approximately 300 mm / min in a direction perpendicular to the length direction of the adhesive tape.

[0359] In 10 test runs, the breakage of the adhesive tape and the remaining degree of the adhesive on the adherend after the adhesive tape is peeled off are visually evaluated according to the following criteria.

[0360] ◎: In all 10 cases, there is no breakage of the adhesive tape and no remaining adhesive, and it is peeled off cleanly.

[0361] ○: It was peeled 10 times without breakage of the adhesive tape, but there was adhesive residue more than once.

[0362] △: There was no breakage of the adhesive tape and no adhesive residue in 6 - 9 times, and it was peeled cleanly.

[0363] ×: In 5 - 10 times, there was breakage of the adhesive tape or adhesive residue, or the adhesive tape could not be stretched and peeled.

[0364] (9) Evaluation of storage stability of adhesive strength

[0365] Before and after the produced adhesive tape was placed at 40°C for 2 weeks, the 180° peel adhesive strength of the adhesive tape was measured respectively. The measurement method used the same measurement method as in the above-mentioned section of "(5) Evaluation of 180° peel adhesive strength". In addition, the 180° peel adhesive strength before the adhesive tape was placed at 40°C for 2 weeks was set as the initial adhesive strength (P0), and the 180° peel adhesive strength after the placement was set as the adhesive strength after 2 weeks at 40°C (P2). And the storage stability of the adhesive tape was calculated by (P2 / P0)×100. Those with 80% or more were qualified.

[0366] Next, the respective materials used in the examples and comparative examples are as described below.

[0367] <Substrate (1)>

[0368] As the substrate material used in substrate (1), a resin composition (1) of styrene - ethylene - butylene - styrene copolymer and styrene - ethylene - butylene copolymer was used. For this resin composition (1), a resin composition in which the structural unit derived from styrene shown in the said chemical formula (A) was 29% by mass and the proportion of styrene - ethylene - butylene copolymer with respect to the total amount of the resin composition was 0.5% by mass was used.

[0369] Using the said resin composition (1), a substrate (1) with a thickness of 50 μm was produced by hot pressing (pressure 0.5 MPa, platen temperature 130°C, pressing time 2 minutes). The breaking stress of substrate (1) was 80 MPa. The elongation at break was 700%. In addition, the stress (modulus) at 50% elongation was 3 MPa.

[0370] <Substrate (2)>

[0371] As the base material material used in the base material (2), a resin composition (2) of a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer is used. For this resin composition (2), a resin composition in which the structural unit derived from styrene shown in the chemical formula (A) is 25% by mass and the proportion of the styrene-isoprene copolymer with respect to the total amount of the resin composition (2) is 16% by mass is used. The resin composition (2) is formed into a base material (2) with a thickness of 50 μm by hot pressing (pressure: 0.5 MPa, platen temperature: 130 °C, pressing time: 2 minutes). The breaking stress of the base material (2) is 10 MPa. The elongation at break is 1200%. In addition, the stress (modulus) at 50% elongation is 1 MPa.

[0372] <Base material (3)>

[0373] As the base material (3), Toray polyester film "Lumirror S10 50μm" is used. The breaking stress of the base material (3) is 220 MPa. The elongation at break is 180%. In addition, the stress (modulus) at 50% elongation is 130 MPa.

[0374] <Adhesive composition>

[0375] The adhesive composition in the present invention contains the following filler and adhesive resin.

[0376] <<Filler>>

[0377] ·Silicone particles (1)

[0378] As the silicone (1), particles having a silicone resin surface and a silicone rubber interior are used (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-602, volume average particle diameter: 30 μm, particle size distribution (D 90 / D 10 ): 5.2).

[0379] ·Silicone particles (2)

[0380] As the silicone particles (2), particles having a silicone resin surface and a silicone rubber interior are used (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-601, volume average particle diameter: 12 μm, particle size distribution (D 90 / D 10 ): 4.4).

[0381] <<Adhesive resin>>

[0382] <<Synthesis of triblock copolymer>>

[0383] (Synthesis Example 1)

[0384] In a 1000 ml flask whose interior has been purged with argon, 500 ml of dry toluene and 80 ml of a dry toluene solution containing 0.75 g of bis(pentamethylcyclopentadienyl)tetrahydrofuran samarium complex [(C 5 Me 5 ) 2 SmMe(THF)] were added to prepare a mixed solution. To this mixed solution, 12.0 ml of methyl methacrylate (MMA) was added at 0 °C, and the mixture was stirred at 0 °C for 30 minutes. Then, 20 ml of the solution (Sample 1) was sampled from the system. After the polymerization of MMA, the polymerization reaction system was cooled to -78 °C, 88.0 ml of n-butyl acrylate (nBA) was added as the second monomer, and the mixture was stirred at -78 °C for 3 hours. Then, 20 ml of the solution (Sample 2) was sampled from the system. After the polymerization of nBA, 12.0 ml of MMA was added as the third monomer to the polymerization system at -78 °C, and the solution was stirred. After the solution became homogeneous, the temperature was raised to 0 °C and further stirred for 1 hour. 50 ml of methanol was added to the resulting reaction mixture, and the reaction was carried out at room temperature for 2 hours to terminate the polymerization. The reaction solution after the termination of polymerization was poured into a large amount of hexane to obtain a precipitated white precipitate. Then, a part of the white precipitate was sampled (Sample 3).

[0385] For each of the polymers in Samples 1 to 3 above, NMR measurement, DSC measurement, and GPC (gel permeation chromatography) measurement were performed. Then, based on the measurement results, the number average molecular weight (Mn), PMMA / PnBA (polymethyl methacrylate block / poly(n-butyl acrylate) block) ratio, etc. were determined. As a result, it was confirmed that the white precipitate was a triblock copolymer of polymethyl methacrylate (PMMA) block - poly(n-butyl acrylate) (PnBA) block - polymethyl methacrylate (PMMA) block (PMMA-b-PnBA-b-PMMA). In addition, it was confirmed that the syndiotacticity of the PMMA block portion of the triblock copolymer (PMMA-b-PnBA-b-PMMA, hereinafter referred to as triblock copolymer (1).) was 71%, the glass transition temperature of this block portion was 113.7 °C, the glass transition temperature of the PnBA block portion was -46.8 °C, the Mn of the entire copolymer was 95936, the Mw / Mn (molecular weight distribution) of the entire copolymer was 1.09, and the ratio of each polymer block was PMMA (11 mass%) - PnBA (78 mass%) - PMMA (11 mass%).

[0386] (Synthesis Example 2)

[0387] In a 1000 ml flask whose interior has been purged with argon, 500 ml of dry toluene and 80 ml of a dry toluene solution containing 0.75 g of bis(pentamethylcyclopentadienyl)tetrahydrofuran samarium complex [(C5 Me 5 ) 2 80 mL of a dry toluene solution of 0.75 g of SmMe(THF) was used to prepare a mixed solution. To this mixed solution, 6.0 mL of methyl methacrylate (MMA) was added at 0 °C, and the mixture was stirred at 0 °C for 30 minutes. Then, 20 mL of the solution (Sample 4) was sampled from the system. After the polymerization of the MMA, the polymerization reaction system was cooled to -78 °C, and 27.2 mL of n-butyl acrylate (nBA) and 22.1 mL of 2-ethylhexyl acrylate (2EHA) were added as the second monomers, and the mixture was stirred at -78 °C for 3 hours. 20 mL of the solution (Sample 5) was sampled from the system. After the polymerization of the nBA, 6.0 mL of MMA was added as the third monomer to the polymerization system at -78 °C, and the solution was stirred. After the solution became homogeneous, the temperature was raised to 0 °C, and the mixture was further stirred for 1 hour. 50 mL of methanol was added to the resulting reaction mixture, and the reaction was carried out at room temperature for 2 hours to terminate the polymerization. The reaction solution after the termination of the polymerization was poured into a large amount of hexane to obtain a precipitated white precipitate. Then, a part of the white precipitate was sampled (Sample 6).

[0388] For each of the polymers in Samples 4 to 6, NMR measurement, DSC measurement, and GPC (gel permeation chromatography) measurement were carried out. Then, based on the measurement results, the number average molecular weight (Mn), the PMMA / PnBA / P2EHA (polymethyl methacrylate / poly(n-butyl acrylate) / poly(2-ethylhexyl acrylate)) ratio, etc. were determined. As a result, it was confirmed that the white precipitate was a triblock copolymer (PMMA-b-PnBA / 2EHA-b-PMMA) of polymethyl methacrylate (PMMA) block-poly(n-butyl acrylate) / poly(2-ethylhexyl acrylate) block-polymethyl methacrylate (PMMA) block. Also, it was confirmed that the syndiotacticity of the PMMA block portion of the triblock copolymer (PMMA-b-PnBA / 2EHA-b-PMMA, hereinafter referred to as triblock copolymer (2).) was 75%, the glass transition temperature of this block portion was 105.8 °C, the glass transition temperature of the PnBA block portion was -53.6 °C, the Mn of the whole copolymer was 51370, the Mw / Mn (molecular weight distribution) of the whole copolymer was 1.15, and the ratio of each polymer block was PMMA (10 mass%)-PnBA (44 mass%) / 2EHA (36 mass%)-PMMA (10 mass%).

[0389] (Synthesis Example 3)

[0390] In a 1000 mL flask with an internal volume replaced with argon, 500 mL of dry toluene and bis(pentamethylcyclopentadienyl)tetrahydrofuran samarium complex [(C5 Me 5 ) 2 80 mL of a dry toluene solution of 0.75 g of SmMe(THF) was used to prepare a mixed solution. To this mixed solution, 20.0 mL of methyl methacrylate (MMA) was added at 0 °C, and the mixture was stirred at 0 °C for 30 minutes. 20 mL of the solution was sampled from the system (Sample 7). After the polymerization of MMA, the polymerization reaction system was cooled to -78 °C, and 148.5 mL of n-butyl acrylate (nBA) was added as the second monomer, and the mixture was stirred at -78 °C for 3 hours. 20 mL of the solution was sampled from the system (Sample 8). After the polymerization of nBA, 20.0 mL of MMA was added as the third monomer to the polymerization system at -78 °C, and the solution was stirred. After the solution became homogeneous, the temperature was raised to 0 °C, and the mixture was further stirred for 1 hour. 50 mL of methanol was added to the resulting reaction mixture, and the reaction was carried out at room temperature for 2 hours to terminate the polymerization. The reaction solution after the polymerization termination was poured into a large amount of hexane to obtain a precipitated white precipitate. Then, a part of the white precipitate was sampled (Sample 9).

[0391] For each of the polymers in Samples 7 to 9, NMR measurement, DSC measurement, and GPC (gel permeation chromatography) measurement were performed. Then, based on the measurement results, the number average molecular weight (Mn), PMMA / PnBA (polymethyl methacrylate block / poly(n-butyl acrylate) block) ratio, etc. were determined. As a result, it was confirmed that the white precipitate was a triblock copolymer (PMMA-b-PnBA-b-PMMA) having a polymethyl methacrylate (PMMA) block - poly(n-butyl acrylate) (PnBA) block - polymethyl methacrylate (PMMA) block. Moreover, it was confirmed that the syndiotacticity of the PMMA block portion of the triblock copolymer (PMMA-b-PnBA-b-PMMA, hereinafter referred to as triblock copolymer (3).) was 71%, the glass transition temperature of this block portion was 108.2 °C, the glass transition temperature of the PnBA block portion was -47.2 °C, the Mn of the whole copolymer was 159585, the Mw / Mn (molecular weight distribution) of the whole copolymer was 1.05, and the ratio of each polymer block was PMMA (11 mass%) - PnBA (78 mass%) - PMMA (11 mass%).

[0392] <<Other binder resins>>

[0393] (Synthesis Example 4)

[0394] As the binder resin, an acrylic random copolymer obtained by the following synthesis was used. 97.97 parts by mass of n-butyl acrylate, 2 parts by mass of acrylic acid, and 0.03 parts by mass of 4-hydroxybutyl acrylate were supplied to ethyl acetate containing 0.2 parts by mass of azobisisobutyronitrile as a polymerization initiator, and solution polymerization was carried out at 77 °C for 8 hours to obtain an acrylic random copolymer. Mw was 700,000, and Mw / Mn (molecular weight distribution) was 4.7.

[0395] (SIS rubber)

[0396] As the binder resin, SIS rubber (styrene-based triblock copolymer) (Quintac 3270 manufactured by Zeon Corporation, Japan, styrene content 24%, SI diblock content 67%) was used. The Mw of the triblock copolymer was 175,000, and Mw / Mn (molecular weight distribution) was 1.05. The Mw of the diblock copolymer was 84,000, and Mw / Mn (molecular weight distribution) was 1.05.

[0397] <Preparation of binder resin composition>

[0398] ·Binder composition (1)

[0399] With respect to 100 parts by mass of the triblock copolymer (1) obtained in Synthesis Example 1 above, 50 parts by mass of a rosin ester tackifying resin (SuperEster A100, Arakawa Chemical Industries, Ltd., softening point 100 °C) was mixed and stirred, and then ethyl acetate was added to obtain a binder resin solution (1) having a solid content of 35% by mass. Next, with respect to 100 parts by mass of the solid content of the binder resin solution (1), 38 parts by mass of silicone particles (1) and ethyl acetate were added, and stirred and mixed to make it uniform, thereby obtaining a binder composition (1) having a solid content of 40% by mass.

[0400] ·Binder composition (2)

[0401] With respect to 100 parts by mass of the triblock copolymer (1) obtained in Synthesis Example 1 above, 50 parts by mass of a rosin ester tackifying resin (Haritac PCJ, Harima Chemical Co., Ltd., softening point 135 °C) was mixed and stirred, and then ethyl acetate was added to obtain a binder resin solution (1) having a solid content of 35% by mass. Next, with respect to 100 parts by mass of the solid content of the binder resin solution (1), 38 parts by mass of silicone particles (2) and ethyl acetate were added, and stirred and mixed to make it uniform, thereby obtaining a binder composition (2) having a solid content of 40% by mass.

[0402] ·Binder composition (3)

[0403] To 100 parts by mass of the triblock copolymer (1) obtained in Synthesis Example 1 above, 50 parts by mass of a terpene phenol-based tackifying resin (YS Polyster T160, manufactured by Yasuhara Chemical Co., Ltd., softening point 160°C) was mixed and stirred, and then ethyl acetate was added thereto, thereby obtaining an adhesive resin solution (3) having a solid content of 35% by mass. Next, to 100 parts by mass of the solid content of the adhesive resin solution (3), 38 parts by mass of silicone particles (2) and ethyl acetate were added, and the mixture was stirred and mixed uniformly, thereby obtaining an adhesive composition (3) having a solid content of 40% by mass.

[0404] · Adhesive composition (4)

[0405] To 100 parts by mass of the triblock copolymer (1) obtained in Synthesis Example 1 above, 50 parts by mass of a terpene phenol-based tackifying resin (YS Polyster T130, manufactured by Yasuhara Chemical Co., Ltd., softening point 130°C) was mixed and stirred, and then ethyl acetate was added thereto, thereby obtaining an adhesive resin solution (4) having a solid content of 35% by mass. Then, to 100 parts by mass of the solid content of the adhesive resin solution (4), 38 parts by mass of silicone particles (2) and ethyl acetate were added, and the mixture was stirred and mixed uniformly, thereby obtaining an adhesive composition (4) having a solid content of 40% by mass.

[0406] · Adhesive composition (5)

[0407] To 100 parts by mass of the triblock copolymer (1) obtained in Synthesis Example 1 above, 10 parts by mass of a terpene phenol-based tackifying resin (YS Polyster T130, manufactured by Yasuhara Chemical Co., Ltd., softening point 130°C) was mixed and stirred, and then ethyl acetate was added thereto, thereby obtaining an adhesive resin solution (4) having a solid content of 35% by mass. Then, to 100 parts by mass of the solid content of the adhesive resin solution (4), 38 parts by mass of silicone particles (2) and ethyl acetate were added, and the mixture was stirred and mixed uniformly, thereby obtaining an adhesive composition (5) having a solid content of 40% by mass.

[0408] · Adhesive composition (6)

[0409] To 100 parts by mass of the triblock copolymer (1) obtained in Synthesis Example 1 above, 75 parts by mass of a terpene phenol-based tackifying resin (YS Polyster T130, manufactured by Yasuhara Chemical Co., Ltd., softening point 130°C) was mixed and stirred, and then ethyl acetate was added thereto, thereby obtaining an adhesive resin solution (4) having a solid content of 35% by mass. Then, to 100 parts by mass of the solid content of the adhesive resin solution (4), 38 parts by mass of silicone particles (2) and ethyl acetate were added, and the mixture was stirred and mixed uniformly, thereby obtaining an adhesive composition (6) having a solid content of 40% by mass.

[0410] · Adhesive composition (7)

[0411] To 100 parts by mass of the triblock copolymer (2) obtained in Synthesis Example 2, 50 parts by mass of a terpene phenol-based tackifying resin (YS Polyster T130, manufactured by Yasuhara Chemical Co., Ltd., softening point 130°C) was mixed and stirred, and then ethyl acetate was added thereto, whereby an adhesive resin solution (5) having a solid content of 35% by mass was obtained. Subsequently, to 100 parts by mass of the solid content of the adhesive resin solution (5), 38 parts by mass of silicone particles (1) and ethyl acetate were added, and the mixture was stirred and mixed uniformly, whereby an adhesive composition (7) having a solid content of 40% by mass was obtained.

[0412] · Adhesive composition (8)

[0413] To 100 parts by mass of the triblock copolymer (3) obtained in Synthesis Example 3, 50 parts by mass of a terpene phenol-based tackifying resin (YS Polyster T160, manufactured by Yasuhara Chemical Co., Ltd., softening point 160°C) was mixed and stirred, and then ethyl acetate was added thereto, whereby an adhesive resin solution (3) having a solid content of 35% by mass was obtained. Subsequently, to 100 parts by mass of the solid content of the adhesive resin solution (3), 38 parts by mass of silicone particles (1) and ethyl acetate were added, and the mixture was stirred and mixed uniformly, whereby an adhesive composition (8) having a solid content of 40% by mass was obtained.

[0414] · Adhesive composition (9)

[0415] To 100 parts by mass of the triblock copolymer (1) obtained in Synthesis Example 1, 50 parts by mass of a terpene phenol-based tackifying resin (YS Polyster T130, manufactured by Yasuhara Chemical Co., Ltd., softening point 130°C) was mixed and stirred, and then ethyl acetate was added thereto, whereby an adhesive composition (9) having a solid content of 40% by mass was obtained.

[0416] · Adhesive composition (10)

[0417] To 100 parts by mass of a styrene-based triblock copolymer (Quintac 3270, manufactured by Nippon Zeon Co., Ltd., styrene content 24%, SI diblock content 67%) as an adhesive resin, 50 parts by mass of a rosin-based tackifying resin (Super Ester A-100, manufactured by Arakawa Chemical Industries, Ltd., softening point 100°C) was mixed and stirred, and then toluene was added thereto, whereby an adhesive resin solution (6) having a solid content of 35% by mass was obtained. To 100 parts by mass of the solid content of the adhesive resin solution (6), 38 parts by mass of silicone particles (1) and toluene were added, and the mixture was stirred and mixed uniformly, whereby an adhesive composition (10) having a solid content of 40% by mass was obtained.

[0418] · Adhesive composition (11)

[0419] To 100 parts by mass of the acrylic random copolymer obtained in Synthesis Example 4 above, 5 parts by mass of a rosin-based tackifying resin (Haritac PCJ, manufactured by Harima Chemicals Group, Inc., softening point 135°C) and 45 parts by mass of a petroleum-based tackifying resin (FTR6125, manufactured by Mitsui Chemicals, Inc., softening point 125°C) were mixed and stirred, and then ethyl acetate was added thereto to obtain an adhesive resin solution (7) having a solid content of 35% by mass. Next, to 100 parts by mass of the solid content of the adhesive resin solution (7), 38 parts by mass of silicone particles (1) and ethyl acetate were added and stirred and mixed to make it uniform, thereby obtaining an adhesive composition (11) having a solid content of 40% by mass.

[0420] 3. "Manufacture of adhesive tape"

[0421] [Example 1]

[0422] The adhesive composition (1) was applied onto a release liner (FilmBina 75E - 0010GT, manufactured by Fujimori Kogyo Co., Ltd., the same hereinafter) with a thickness after drying of 50 μm using a coater and dried at 80°C for 3 minutes to produce an adhesive layer. Next, after subjecting both surfaces of the substrate (1) as the substrate layer to corona treatment to achieve a wetting tension of 52 mN / m, the adhesive layer was adhered to both surfaces, and the laminate structure of the substrate layer and the adhesive layer was laminated under a pressure of 0.2 MPa, thereby manufacturing the adhesive tape of Example 1. The adhesive tape obtained by evaluating through the above method, and the results are shown in Table 1.

[0423] [Example 2]

[0424] In the manufacture of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (2), and except for this, the adhesive tape of Example 2 was manufactured in the same manner as in Example 1. The adhesive tape obtained by evaluating through the above method, and the results are shown in Table 1.

[0425] [Example 3]

[0426] In the manufacture of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (3), and except for this, the adhesive tape of Example 3 was manufactured in the same manner as in Example 1. The adhesive tape obtained by evaluating through the above method, and the results are shown in Table 1.

[0427] [Example 4]

[0428] In the production of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (4), and other than this, the adhesive tape of Example 4 was produced using the same method as in Example 1. The results of evaluating the adhesive tape obtained by the above method are shown in Table 1.

[0429] 〔Example 5〕

[0430] In the production of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (5), and other than this, the adhesive tape of Example 5 was produced using the same method as in Example 1. The results of evaluating the adhesive tape obtained by the above method are shown in Table 1.

[0431] 〔Example 6〕

[0432] In the production of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (6), and other than this, the adhesive tape of Example 6 was produced using the same method as in Example 1. The results of evaluating the adhesive tape obtained by the above method are shown in Table 1.

[0433] 〔Example 7〕

[0434] In the production of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (7), and other than this, the adhesive tape of Example 7 was produced using the same method as in Example 1. The results of evaluating the adhesive tape obtained by the above method are shown in Table 1.

[0435] 〔Example 8〕

[0436] In the production of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (8), and other than this, the adhesive tape of Example 8 was produced using the same method as in Example 1. The results of evaluating the adhesive tape obtained by the above method are shown in Table 1.

[0437] 〔Example 9〕

[0438] In the production of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (9), and other than this, the adhesive tape of Example 9 was produced using the same method as in Example 1. The results of evaluating the adhesive tape obtained by the above method are shown in Table 1.

[0439] 〔Example 10〕

[0440] In the production of the adhesive tape of Example 1, the substrate (1) was changed to the substrate (2), and other than this, the adhesive tape of Example 10 was produced using the same method as in Example 4. The results of evaluating the adhesive tape obtained by the above method are shown in Table 1.

[0441] [Comparative Example 1]

[0442] In the production of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (10), and other than that, the adhesive tape of Comparative Example 1 was produced in the same manner as in Example 1. The obtained adhesive tape was evaluated by the said method, and the results are shown in Table 2.

[0443] [Comparative Example 2]

[0444] In the production of the adhesive tape of Example 1, the adhesive composition (1) was changed to the adhesive composition (11), and other than that, the adhesive tape of Comparative Example 2 was produced in the same manner as in Example 1. The obtained adhesive tape was evaluated by the above method, and the results are shown in Table 2. It should be noted that the product of the softening point temperature [°C] of the tackifying resin and the addition amount of the tackifying resin (the addition amount of the said tackifying resin when the triblock copolymer is 100 parts by mass) in Comparative Example 2 was 6300 (= 135°C × 5 parts by mass + 125°C × 45 parts by mass).

[0445] [Comparative Example 3]

[0446] In the production of the adhesive tape of Example 1, the base material (1) was changed to the base material (3), and other than that, the adhesive tape of Comparative Example 3 was produced in the same manner as in Example 1. The obtained adhesive tape was evaluated by the above method, and the results are shown in Table 2.

[0447] [Table 1]

[0448]

[0449] [Table 2]

[0450]

[0451] Based on the experimental results in Table 1 and Table 2, it was confirmed that the adhesive tape of the present invention exhibited excellent high load holding force, re-peelability over time, and storage stability with respect to the adhesive force compared to the comparative examples.

Claims

1. An adhesive tape, which comprises a base material layer and an adhesive layer, The breaking stress of the base material layer is 1 to 100 MPa, and the elongation at break is 300 to 3000%, The adhesive layer contains a filler, and the particle size distribution D90 / D10 of the filler is 2.5 to 20, The adhesive layer contains a tackifying resin and a triblock copolymer having repeating units represented by the general formula (1): ； In the above general formula (1), A, B, and C each independently represent a repeating unit, A and C each independently represent an alkyl methacrylate monomer unit, B represents an alkyl acrylate monomer unit, p, q, and r each independently represent the degree of polymerization of each monomer unit, A and C are the same or are alkyl methacrylate monomer units having different chemical structures, In the above general formula (1), * is a bonding position indicating bonding to other atoms, The weight average molecular weight Mw of the triblock copolymer is 50,000 to 300,000, and the number average molecular weight Mn is 50,000 to 300,000, In the adhesive layer, 30 to 100% by mass of the triblock copolymer is contained relative to the total amount of the adhesive resin, The average particle size of the filler is 0.1 to 40 μ m The content of the filler is 1 to 300% by mass relative to 100% by mass of the adhesive resin.

2. The adhesive tape according to claim 1, wherein, The weight average molecular weight Mw of the triblock copolymer is 100,000 to 250,000, and the number average molecular weight Mn is 100,000 to 250,000.

3. The adhesive tape according to claim 1 or 2, wherein, The softening point of the tackifying resin is 95 °C or higher.

4. The adhesive tape according to claim 1 or 2, wherein, The temperature [°C] of the softening point of the tackifying resin × the addition amount of the tackifying resin is 1300 to 13000, and the addition amount of the tackifying resin is the addition amount of the tackifying resin when the triblock copolymer is 100 parts by mass.

5. The adhesive tape according to claim 1 or 2, wherein, The base material layer contains a vinyl aromatic block copolymer.

6. The adhesive tape according to claim 1 or 2, wherein, The peel adhesion of the adhesive tape is 5 N / 20 mm or more.

7. The adhesive tape according to claim 1 or 2, wherein, The shear adhesion of the adhesive tape is 1.0 MPa or more.

8. The adhesive tape according to claim 1 or 2, wherein, The adhesive layer contains 10 to 150 parts by mass of the tackifying resin relative to 100 parts by mass of the triblock copolymer.

9. The adhesive tape according to claim 1, wherein, The particle size distribution D90 / D10 of the filler is 2.5 to 15.

10. The adhesive tape according to claim 1, wherein, The content of the filler in the adhesive layer is 1 to 100% by mass relative to 100% by mass of the adhesive resin.

11. The adhesive tape according to claim 1 or 2, wherein, In the adhesive layer, 50 to 95% by mass of the triblock copolymer is contained relative to the total amount of the adhesive resin.

12. The adhesive tape according to claim 1 or 2, wherein, The syndiotacticity of the polymer block in the "-(A) p -” part of the triblock copolymer exhibits a proportion of rr triads of more than 65%, The syndiotacticity of the polymer block of the "-(C) r -” part of the triblock copolymer exhibits a proportion of rr triads of more than 65%.

13. The adhesive tape according to claim 1 or 2, wherein, On a SUS304 steel plate with a width of 25 mm × a width of 80 mm specified in JIS Z0237, one surface of each adhesive tape cut into a width of 25 mm × a length of 25 mm is adhered by reciprocating pressing at a speed of 300 mm per minute with a 5-kg roller at room temperature, and then it is left for 30 minutes under the conditions of 23°C. Then, the reverse side of the test piece is adhered to a SUS304 steel plate with a width of 25 mm × a width of 80 mm specified in JIS Z0237 by reciprocating pressing at a speed of 300 mm per minute with a 5-kg roller at room temperature. Next, after being left in a 40°C atmosphere for 30 minutes, a 5-kg heavy object is installed on the handle part of the test piece and allowed to sag, and then the time until it falls is 120 minutes or more at 23°C and 50% RH.

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