Adhesive tape, adhesive composition, and adhesive

Abstract

The present invention relates to an adhesive tape having an adhesive layer containing an adhesive and satisfying the following first configuration. In a first configuration, the binder contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, and in the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked by a crosslinking agent. The vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b) or (c): (a) an aromatic group-containing (meth) acrylate and a nitrogen atom-containing (meth) acrylate, and (b) a polymer having a structural unit derived from an aromatic group-containing (meth) acrylate and a structural unit derived from a nitrogen atom-containing (meth) acrylate. And (c) a polymer having a structural unit derived from an aromatic group-containing (meth) acrylate and a polymer having a structural unit derived from a nitrogen atom-containing (meth) acrylate.

Description

Technical Field

[0001] This invention relates to adhesive tapes. Additionally, this invention relates to adhesive compositions. Furthermore, this invention relates to adhesives obtained from these adhesive compositions. Background Technology

[0002] Adhesive tapes having an adhesive layer containing an adhesive composition have been widely used for fixing components in electronic components, vehicles, houses, and building materials (e.g., Patent Documents 1-3). Specifically, adhesive tapes are used, for example, to bond a cover plate for protecting the surface of a portable electronic device to a touch panel module or a display panel module, or to bond a touch panel module to a display panel module.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-052050

[0006] Patent Document 2: Japanese Patent Application Publication No. 2015-021067

[0007] Patent Document 3: Japanese Patent Application Publication No. 2015-120876 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] For adhesive tapes used in the electronics field, high adhesive strength is required to demonstrate long-term reliability. On the other hand, reprocessability is also required, allowing for peeling off without residue from the adhered materials. Typically, to improve adhesive strength, the adhesive in the adhesive layer needs to be made soft to enhance adhesion; conversely, to improve reprocessability, the adhesive in the adhesive layer needs to be hardened to prevent the adhesive layer from cracking during peeling. Therefore, to improve both adhesive strength and reprocessability, it is necessary to balance these opposing properties of adhesive softness and hardness.

[0010] The object of this invention is to provide an adhesive tape that combines high adhesion and excellent reprocessability. Furthermore, the object of this invention is to provide an adhesive composition that simultaneously exhibits high adhesion and excellent reprocessability. Additionally, the object of this invention is to provide an adhesive obtained from this adhesive composition.

[0011] Methods for solving problems

[0012] This disclosure 1 relates to an adhesive tape having an adhesive layer containing an adhesive, wherein the adhesive tape satisfies at least one of the following first and second configurations.

[0013] First composition: The adhesive described above contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, wherein the vinyl monomer polymer and the urethane polymer are crosslinked by a crosslinking agent, and the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from (a), (b) or (c) below:

[0014] (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms,

[0015] (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms,

[0016] (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms;

[0017] The second component: the thickness of the adhesive layer is 50 μm or more, the tensile breaking stress of the adhesive layer at 23°C is 0.50 MPa or more, and the 180° peel force of the adhesive tape against SUS at 23°C and a peel speed of 300 mm / min is 5.0 N / inch or more and 30.0 N / inch or less.

[0018] This disclosure 2 relates to the adhesive tape of this disclosure 1, wherein the adhesive layer has one peak of loss tangent (tanδ) in a temperature range of -10°C to 30°C when measured at a frequency of 1 Hz, and the half-width of the loss tangent peak is 40°C or less, and the shear storage modulus (G') of the adhesive layer at 25°C is 1.0 MPa or less.

[0019] This disclosure 3 relates to an adhesive tape of disclosure 1 or 2, wherein, in the first configuration described above, the thickness of the adhesive layer is 50 μm or more, the tensile breaking stress of the adhesive layer at 23°C is 0.50 MPa or more, and the 180° peel force of the adhesive tape against SUS at 23°C at a peel speed of 300 mm / min is 5.0 N / inch or more and 30.0 N / inch or less.

[0020] This disclosure 4 relates to an adhesive tape of disclosure 1 or 2, wherein, in the second configuration described above, the adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, wherein the vinyl monomer polymer and the urethane polymer are crosslinked by a crosslinking agent, and the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from (a), (b) or (c) below.

[0021] (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms

[0022] (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms.

[0023] (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

[0024] This disclosure 5 relates to adhesive tapes of disclosures 1, 2, 3 or 4, wherein the nitrogen-containing (meth)acrylate comprises at least one selected from (meth)acrylates containing urethane bonds and (meth)acrylates containing imide bonds.

[0025] This disclosure 6 relates to the adhesive tape of this disclosure 5, wherein the nitrogen-containing (meth)acrylate comprises (meth)acrylate containing urethane bonds.

[0026] This disclosure 7 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5 or 6, wherein, of the total 100 parts by mass of the above-mentioned structural units derived from (meth)acrylate containing aromatic groups and the above-mentioned structural units derived from (meth)acrylate containing nitrogen atoms, the content of the structural units derived from (meth)acrylate containing aromatic groups is 5 parts by mass or more and 95 parts by mass or less.

[0027] This disclosure 8 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6 or 7, wherein the vinyl monomer polymer further has structural units derived from hydroxyl-containing (meth)acrylates.

[0028] This disclosure 9 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7 or 8, wherein the vinyl monomer polymer further has structural units derived from (meth)acrylate alkyl esters.

[0029] This disclosure 10 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein the urethane polymers described above have at least one structural unit selected from polyether diols, polyester diols, and polycarbonate diols.

[0030] This disclosure 11 relates to the adhesive tape of this disclosure 10, wherein the urethane polymer has at least one structural unit selected from polyester diol and polycarbonate diol.

[0031] This disclosure 12 relates to the adhesive tape of this disclosure 11, wherein the urethane polymer has structural units derived from polycarbonate diol.

[0032] This disclosure 13 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, wherein the urethane polymers described above have structural units derived from compounds containing aromatic groups.

[0033] This disclosure 14 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13, wherein, in a total of 100 parts by mass of the vinyl monomer polymer and the urethane polymer, the content of the urethane polymer is 5 parts by mass or more and 90 parts by mass or less.

[0034] This disclosure 15 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14, wherein the adhesives further contain tackifying resins.

[0035] This disclosure 16 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, wherein the elongation at break of the adhesive layer at 23°C is 300% or more.

[0036] This disclosure 17 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16, wherein the gel content of the adhesive layer is 30% by mass or more and 99% by mass or less.

[0037] This disclosure 18 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 or 17, wherein the Young's modulus of the adhesive layer at 23°C is 0.010 MPa or more and 10 MPa or less.

[0038] This disclosure 19 relates to an adhesive tape of disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18, having a substrate having the adhesive layer thereon on at least one side of the substrate.

[0039] This disclosure 20 relates to the adhesive tape of this disclosure 19, wherein the substrate comprises a foam substrate.

[0040] This disclosure 21 relates to adhesive tapes of disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 that do not have a substrate.

[0041] This disclosure 22 relates to an adhesive composition comprising a vinyl monomer polymer and a urethane polymer, wherein the vinyl monomer polymer has structural units derived from a compound (C1) selected from (a), (b) or (c) below.

[0042] (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms

[0043] (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms.

[0044] (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

[0045] This disclosure 23 relates to an adhesive composition of this disclosure 22, wherein the nitrogen-containing (meth)acrylate comprises at least one selected from (meth)acrylates containing urethane bonds and (meth)acrylates containing imide bonds.

[0046] This disclosure 24 relates to adhesive compositions of this disclosure 23, wherein the nitrogen-containing (meth)acrylate comprises (meth)acrylates containing urethane bonds.

[0047] This disclosure 25 relates to adhesive compositions of disclosures 22, 23 or 24, wherein, of the total 100 parts by mass of the above-mentioned structural units derived from aromatic groups and structural units derived from nitrogen-containing (meth)acrylates, the content of the structural units derived from aromatic groups is 5 parts by mass or more and 95 parts by mass or less.

[0048] This disclosure 26 relates to adhesive compositions of disclosures 22, 23, 24 or 25, wherein the vinyl monomer polymer further has structural units derived from hydroxyl-containing (meth)acrylates.

[0049] This disclosure 27 relates to adhesive compositions of disclosures 22, 23, 24, 25 or 26, wherein the vinyl monomer polymer further has structural units derived from (meth)acrylate alkyl esters.

[0050] This disclosure 28 relates to adhesive compositions of disclosures 22, 23, 24, 25, 26 or 27, wherein the urethane polymer has at least one structural unit selected from polyether diol, polyester diol and polycarbonate diol.

[0051] This disclosure 29 relates to an adhesive composition of this disclosure 28, wherein the urethane polymer has at least one structural unit selected from polyester diol and polycarbonate diol.

[0052] This disclosure 30 relates to an adhesive composition of this disclosure 29, wherein the urethane polymer has structural units derived from polycarbonate diol.

[0053] This disclosure 31 relates to adhesive compositions of disclosures 22, 23, 24, 25, 26, 27, 28, 29 or 30, wherein the urethane polymers described above have structural units derived from compounds containing aromatic groups.

[0054] This disclosure 32 relates to adhesive compositions of disclosures 22, 23, 24, 25, 26, 27, 28, 29, 30 or 31, wherein, of a total of 100 parts by weight of the vinyl monomer polymer and the urethane polymer, the content of the urethane polymer is 5 parts by weight or more and 90 parts by weight or less.

[0055] This disclosure 33 relates to adhesive compositions of disclosures 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 or 32, which further contain tackifying resins.

[0056] This disclosure 34 relates to an adhesive comprising a crosslinked product of the vinyl monomer polymer and the urethane polymer in the adhesive composition of this disclosure 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32 or 33.

[0057] This disclosure 35 relates to an adhesive of this disclosure 34, wherein, in the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked by a crosslinking agent.

[0058] The present invention will now be described in detail.

[0059] It should be noted that in the adhesive tape of the present invention, matters common to the first and second components described above are described as matters not specifically specified.

[0060] The inventors have studied the composition of the adhesive layer and the physical properties of the adhesive layer and the adhesive tape, which are adhesive tapes having an adhesive layer containing an adhesive.

[0061] Regarding the composition of the adhesive layer, adhesives containing crosslinked products having specific urethane polymer structures and vinyl monomer polymer structures were investigated. Furthermore, for this vinyl monomer polymer, vinyl monomer polymers having structural units derived from: (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms; polymers having structural units derived from (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms; or polymers having structural units derived from (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms.

[0062] In addition, the physical properties of the adhesive layer and adhesive tape were investigated, including adjusting the thickness and tensile fracture stress of the adhesive layer, as well as the 180° peel force of the adhesive tape on SUS.

[0063] The results showed that an adhesive tape that combines high adhesion and excellent reprocessability could be obtained, thus completing the present invention.

[0064] The adhesive tape of the present invention has an adhesive layer containing an adhesive.

[0065] The adhesive tape of the present invention satisfies at least one configuration selected from the first configuration and the second configuration described below.

[0066] First composition: The adhesive described above contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, wherein the vinyl monomer polymer and the urethane polymer are crosslinked by a crosslinking agent, and the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from (a), (b) or (c) below:

[0067] (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms,

[0068] (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms,

[0069] (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

[0070] The second component: the thickness of the adhesive layer is 50 μm or more, the tensile breaking stress of the adhesive layer at 23°C is 0.50 MPa or more, and the 180° peel force of the adhesive tape against SUS at 23°C and a peel speed of 300 mm / min is 5.0 N / inch or more and 30.0 N / inch or less.

[0071] By making the adhesive tape of the present invention satisfy at least one of the above-described first and second configurations, the adhesive tape of the present invention can achieve both high adhesion and excellent reprocessability.

[0072] In the first configuration described above, the adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure. In this first configuration, by including the crosslinked product in the adhesive, the adhesive tape of the present invention exhibits excellent reprocessability due to the urethane polymer structure of the crosslinked product. Furthermore, by utilizing the vinyl monomer polymer structure of the crosslinked product, the adhesive tape of the present invention possesses high adhesive strength. Additionally, since the crosslinked product is a structure formed by crosslinking a vinyl monomer polymer structure with a urethane polymer structure, the adhesive becomes harder, thus improving the reprocessability of the adhesive tape of the present invention. In other words, in the first configuration described above, by including the crosslinked product in the adhesive, the adhesive tape of the present invention can achieve both high adhesive strength and excellent reprocessability.

[0073] Furthermore, in the second configuration described above, the adhesive preferably contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure. In the second configuration, by including the crosslinked product in the adhesive, the urethane polymer structure of the crosslinked product enhances the reprocessability of the adhesive tape of the present invention. On the other hand, by utilizing the vinyl monomer polymer structure of the crosslinked product, the adhesive tape of the present invention exhibits higher adhesive strength. Additionally, since the crosslinked product is a structure formed by crosslinking a vinyl monomer polymer structure with a urethane polymer structure, the adhesive becomes harder, further improving the reprocessability of the adhesive tape of the present invention. In other words, in the second configuration described above, by including the crosslinked product in the adhesive, the adhesive tape of the present invention achieves both higher adhesive strength and superior reprocessability.

[0074] In the first configuration described above, the vinyl monomer polymer has structural units derived from compounds (C1) selected from (a), (b) or (c) below.

[0075] (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms

[0076] (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms.

[0077] (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

[0078] The aforementioned compound (C1) exhibits excellent compatibility with urethane polymers. Therefore, in the first configuration described above, by incorporating structural units derived from compound (C1) selected from (a), (b), or (c) above, the vinyl monomer polymer exhibits excellent compatibility with the urethane polymer described later. Consequently, the crosslinking of the aforementioned compound (C1) and the vinyl monomer polymer having structural units derived from the aforementioned compound (C1) with the urethane polymer described later proceeds uniformly. As a result, the crosslinked product possesses both a vinyl monomer polymer structure and a urethane polymer structure, enabling the adhesive tape of the present invention to achieve both high adhesion and excellent reprocessability. Furthermore, by ensuring excellent compatibility between the aforementioned compound (C1) and the aforementioned urethane polymer, the adhesive layer can suppress interface formation caused by microphase separation, making the adhesive layer less prone to breakage during stretching, resulting in excellent reprocessability of the adhesive tape of the present invention.

[0079] In addition, in the second configuration described above, the vinyl monomer polymer preferably has a structural unit derived from a compound (C1) selected from (a), (b) or (c) below.

[0080] (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms

[0081] (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms.

[0082] (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

[0083] The aforementioned compound (C1) exhibits excellent compatibility with urethane polymers. Therefore, in the second configuration described above, by incorporating structural units derived from compound (C1) selected from (a), (b), or (c) above, the compatibility between the vinyl monomer polymer and the urethane polymer described later is further enhanced. Consequently, the crosslinking of the aforementioned compound (C1) and the vinyl monomer polymer having structural units derived from the aforementioned compound (C1) with the urethane polymer described later proceeds more uniformly. As a result, the crosslinked product possesses both a vinyl monomer polymer structure and a urethane polymer structure, enabling the adhesive tape of the present invention to achieve both higher adhesive strength and superior reprocessability. Furthermore, by ensuring excellent compatibility between the aforementioned compound (C1) and the aforementioned urethane polymer, the adhesive layer can further suppress interface formation caused by microphase separation, making the adhesive layer less prone to breakage during stretching, resulting in even better reprocessability of the adhesive tape of the present invention.

[0084] It should be noted that in this specification, "(meth)acrylate" refers to acrylate or methacrylate.

[0085] Examples of (meth)acrylates containing aromatic groups include: benzyl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, methylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and 2-([1,1'-biphenyl]-2-oxy)ethyl acrylate. From the viewpoint of adhesive properties, phenoxyethyl acrylate and phenoxydiethylene glycol acrylate are preferred.

[0086] The preferred lower limit for the content of the structural units derived from aromatic (meth)acrylates in the above-mentioned vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass. By making the content of the structural units derived from aromatic (meth)acrylates 5% by mass or more, the adhesive becomes harder, thereby further improving reprocessability. By making the content of the structural units derived from aromatic (meth)acrylates 95% by mass or less, the adhesive does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength. The more preferred lower limit for the content of the structural units derived from aromatic (meth)acrylates 10% by mass, the more preferred upper limit is 90% by mass, the further preferred lower limit is 15% by mass, and the further preferred upper limit is 85% by mass.

[0087] Examples of nitrogen-containing (meth)acrylates include (meth)acrylates containing urethane bonds, (meth)acrylates containing imide bonds, and (meth)acrylamide. From the viewpoint of superior compatibility with urethane polymers described later, the nitrogen-containing (meth)acrylate preferably comprises at least one selected from (meth)acrylates containing urethane bonds and (meth)acrylates containing imide bonds, and more preferably comprises (meth)acrylates containing urethane bonds.

[0088] Examples of (meth)acrylates containing urethane bonds include 2-acrylate-2-[[(butylamino)-carbonyl]oxo]ethyl ester.

[0089] Examples of the above-mentioned (meth)acrylates containing imide bonds include N-[2-(acryloyloxy)ethyl]phthalimide.

[0090] The preferred lower limit for the content of the nitrogen-containing (meth)acrylate structural units in the overall vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass. By making the content of the nitrogen-containing (meth)acrylate structural units at 5% by mass or more, the adhesive becomes harder, thus further improving the reprocessability of the adhesive tape of the present invention. By making the content of the nitrogen-containing (meth)acrylate structural units at 95% by mass or less, the adhesive does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength. The more preferred lower limit for the content of the nitrogen-containing (meth)acrylate structural units is 10% by mass, the more preferred upper limit is 90% by mass, the further preferred lower limit is 15% by mass, and the further preferred upper limit is 85% by mass.

[0091] Of the total 100 parts by mass of the structural units derived from (meth)acrylate containing aromatic groups and the structural units derived from (meth)acrylate containing nitrogen atoms, the preferred lower limit for the content of the structural units derived from (meth)acrylate containing aromatic groups is 5 parts by mass, and the preferred upper limit is 95 parts by mass. By keeping the content of the structural units derived from (meth)acrylate containing aromatic groups within the above range, the compatibility of the compound (C1) and the vinyl monomer polymer having the structural units derived from the compound (C1) with the urethane polymer described later becomes more excellent. Therefore, the adhesive tape of the present invention can achieve both higher adhesive strength and better reprocessability. The more preferred lower limit for the content of the structural units derived from (meth)acrylate containing aromatic groups is 10 parts by mass, the more preferred upper limit is 90 parts by mass, the further preferred lower limit is 15 parts by mass, and the further preferred upper limit is 85 parts by mass.

[0092] The aforementioned vinyl monomer polymer preferably further has structural units derived from hydroxyl-containing (meth)acrylates.

[0093] By incorporating structural units derived from hydroxyl-containing (meth)acrylates into the aforementioned vinyl monomer polymer, crosslinking of the aforementioned compound (C1) and the vinyl monomer polymer having structural units derived from the aforementioned compound (C1) with the urethane polymer described later by the crosslinking agent becomes easier. As a result, the adhesive further cures, the tensile strength is further improved, and thus the reprocessability of the adhesive tape of the present invention is further improved.

[0094] It should be noted that, in this specification, the structural unit derived from (meth)acrylate containing aromatic groups and hydroxyl groups is the structural unit derived from (meth)acrylate containing aromatic groups.

[0095] Furthermore, in this specification, the structural units derived from (meth)acrylates containing nitrogen atoms and hydroxyl groups are structural units derived from (meth)acrylates containing nitrogen atoms.

[0096] Examples of hydroxyl-containing (meth)acrylates include: 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and tetrahydroxyfurfuryl (meth)acrylate.

[0097] The preferred lower limit for the content of the structural units derived from hydroxyl-containing (meth)acrylate in the overall vinyl monomer polymer is 0.01% by mass, and the preferred upper limit is 20% by mass. By making the content of the structural units derived from hydroxyl-containing (meth)acrylate at 0.01% by mass or more, the reprocessability of the adhesive tape of the present invention is further improved. By making the content of the structural units derived from hydroxyl-containing (meth)acrylate at 20% by mass or less, the adhesive does not become too stiff, and the adhesive tape of the present invention can exhibit higher adhesive strength. The more preferred lower limit for the content of the structural units derived from hydroxyl-containing (meth)acrylate is 0.1% by mass, the more preferred upper limit is 10% by mass, the further preferred lower limit is 0.5% by mass, and the further preferred upper limit is 5.0% by mass.

[0098] The aforementioned vinyl monomer polymers may further have structural units derived from alkyl (meth)acrylates.

[0099] Examples of the aforementioned alkyl methacrylates include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, n-heptyl methacrylate, 2-ethylhexyl methacrylate, 2-octyl methacrylate, isooctyl methacrylate, n-nonyl methacrylate, isononyl methacrylate, lauryl methacrylate, myristyl methacrylate, cetyl methacrylate, isostearyl acrylate, and eicosyl methacrylate. From the viewpoint of compatibility with the urethane polymers described later, alkyl methacrylates with short alkyl chains are preferred; specifically, n-butyl methacrylate and 2-ethylhexyl methacrylate are preferred.

[0100] The aforementioned vinyl monomer polymer may further have structural units derived from (meth)acrylates containing aromatic groups, structural units derived from (meth)acrylates containing nitrogen atoms, structural units derived from (meth)acrylates containing hydroxyl groups, and structural units derived from other monomers other than the structural units derived from (meth)acrylates containing alkyl esters.

[0101] When the aforementioned vinyl monomer polymer has structural units derived from (b) above, the preferred lower limit of the weight-average molecular weight (Mw) of the polymer having structural units derived from aromatic (meth)acrylates and structural units derived from nitrogen-containing (meth)acrylates is 200,000, and the preferred upper limit is 2,000,000. By making the weight-average molecular weight of the polymer having structural units derived from aromatic (meth)acrylates and structural units derived from nitrogen-containing (meth)acrylates 200,000 or more, the reprocessability of the adhesive tape of the present invention is further improved. By making the weight-average molecular weight of the polymer having structural units derived from aromatic (meth)acrylates and structural units derived from nitrogen-containing (meth)acrylates 2,000,000 or less, the adhesive strength of the adhesive tape of the present invention is further improved. The preferred lower limit for the weight-average molecular weight of the polymer having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms is 400,000, the preferred upper limit is 1,500,000, the further preferred lower limit is 600,000, and the further preferred upper limit is 1,000,000.

[0102] When the aforementioned vinyl monomer polymer has structural units derived from (c) above, the preferred lower limit of the weight-average molecular weight (Mw) of the polymer having structural units derived from (meth)acrylate containing aromatic groups is 200,000, and the preferred upper limit is 2,000,000. By making the weight-average molecular weight of the polymer having structural units derived from (meth)acrylate containing aromatic groups 200,000 or more, the reprocessability of the adhesive tape of the present invention is further improved. By making the weight-average molecular weight of the polymer having structural units derived from (meth)acrylate containing aromatic groups 2,000,000 or less, the adhesive strength of the adhesive tape of the present invention is further improved. The more preferred lower limit of the weight-average molecular weight of the polymer having structural units derived from (meth)acrylate containing aromatic groups is 400,000, the more preferred upper limit is 1,500,000, the further preferred lower limit is 600,000, and the further preferred upper limit is 1,000,000.

[0103] When the aforementioned vinyl monomer polymer has structural units derived from (c) above, the preferred lower limit of the weight-average molecular weight (Mw) of the polymer having structural units derived from nitrogen-containing (meth)acrylate is 200,000, and the preferred upper limit is 2,000,000. By making the weight-average molecular weight of the polymer having structural units derived from nitrogen-containing (meth)acrylate more than 200,000, the reprocessability of the adhesive tape of the present invention is further improved. By making the weight-average molecular weight of the polymer having structural units derived from nitrogen-containing (meth)acrylate less than 2,000,000, the adhesive strength of the adhesive tape of the present invention is further improved. The more preferred lower limit of the weight-average molecular weight of the polymer having structural units derived from nitrogen-containing (meth)acrylate is 400,000, the more preferred upper limit is 1,500,000, the further preferred lower limit is 600,000, and the further preferred upper limit is 1,000,000.

[0104] In this specification, weight-average molecular weight (Mw) refers to the weight-average molecular weight calculated based on standard polystyrene, as determined by gel permeation chromatography (GPC). Specifically, for example, a Waters "2690 Separations Module" can be used as the measuring instrument, a Showa Denko "GPC KF-806L" column can be used as the column, tetrahydrofuran can be used as the solvent, and the determination can be performed at a sample flow rate of 1 mL / min and a column temperature of 40 °C.

[0105] When the compound (C1) is as described in (b) or (c), the method for manufacturing the vinyl monomer polymer can be, for example, by polymerizing a mixture of monomers, such as the aromatic (meth)acrylate, the nitrogen-containing (meth)acrylate, the hydroxyl-containing (meth)acrylate, the alkyl (meth)acrylate, and other monomers, in the presence of a polymerization initiator through a free radical reaction.

[0106] In addition, when the compound (C1) is as described in (a), in addition to the method for manufacturing the vinyl monomer polymer described above, polymerization can also be carried out by the following method, thereby obtaining an adhesive at the same time as obtaining the vinyl monomer polymer. The method is as follows: applying a mixture of the monomer mixture, photopolymerization initiator and the urethane polymer, etc., to a release PET film or substrate using an applicator, sealing the upper surface after coating with a release PET film, or preventing the coated surface from contacting air under a nitrogen atmosphere, and then subjecting it to UV irradiation.

[0107] As a method for polymerizing the above-mentioned monomer mixture, conventionally known methods can be used, such as solution polymerization (boiling point polymerization or isothermal polymerization), UV polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, etc. Among these, solution polymerization and UV polymerization are preferred from the perspective of obtaining adhesive tape with higher adhesive strength.

[0108] When solution polymerization is used as the method for polymerizing the above-mentioned monomer mixture, examples of reaction solvents include ethyl acetate, toluene, methyl ethyl ketone, dimethyl sulfoxide, ethanol, acetone, and diethyl ether. These reaction solvents can be used alone or in combination of two or more.

[0109] Examples of polymerization initiators include azo compounds and organic peroxides in the case of solution polymerization, and photopolymerization initiators such as benzophenone compounds, acetophenone compounds, alkyl phenyl ketone compounds, acylphosphine oxide compounds, dicenecene compounds, oxime ester compounds, benzoin ether compounds, and thioxanone in the case of UV polymerization.

[0110] Examples of the aforementioned azo compounds include: 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylpentanitrile), 2,2'-azobis(4-methoxy-2,4-dimethylpentanitrile), 1,1-azobis(cyclohexane-1-carboxylonitrile), 1-((1-cyano-1-methylethyl)azo)formamide, 4,4'-azobis(4-cyanopentanoic acid), dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis(2-methyl-N-(1,1'-bis(hydroxymethyl)-2-hydroxyethyl)propionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2'-azobis(2-azobis(2-methyl ... Bis(N-(2-propenyl)-2-methylpropionamide), 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis(2-(2-imidazolin-2-yl)propane) dihydrochloride, 2,2'-azobis(2-(1-(2-hydroxyethyl)-2-imidazolin-2-yl)propane) dihydrochloride Salts, 2,2'-azobis(2-(2-imidazolin-2-yl)propane), 2,2'-azobis(2-amidinylpropane) dihydrochloride, 2,2'-azobis(N-(2-carboxyethyl)-2-methylpropanediamine) tetrahydrate, 2,2'-azobis(1-imino-1-pyrrolyl-2-methylpropane) dihydrochloride, 2,2'-azobis(2,4,4-trimethylpentane), etc. These azo compounds can be used alone or in combination of two or more.

[0111] Examples of the aforementioned organic peroxides include: 1,1-bis(tert-hexylperoxide)-3,3,5-trimethylcyclohexane, tert-hexyl peroxypentanoate, tert-butyl peroxypentanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxide)hexane, tert-hexyl peroxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-3,5,5-trimethylhexanoate, and tert-butyl peroxylaurate. These organic peroxides can be used alone or in combination of two or more.

[0112] Examples of photopolymerization initiators include: Omnirad 184, Omnirad 369, Omnirad 379, Omnirad 379EG, Omnirad 651, Omnirad 784, Omnirad 819, Omnirad 907, Omnirad 2959, Omnirad TPO (all manufactured by IGM Resins), Omnirad OXE01 (manufactured by BASF), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.). These photopolymerization initiators can be used alone or in combination of two or more.

[0113] The above-mentioned urethane polymers are compounds obtained by reacting polyol compounds with polyisocyanate compounds.

[0114] When the aforementioned polyol compound is a polyol diol with a small number of carbon atoms, a highly polar hard segment can be obtained as the structural unit of the aforementioned urethane polymer. By including the aforementioned hard segment in the aforementioned urethane polymer, the cohesive strength of the resulting urethane polymer is further improved through physical crosslinking via hydrogen bonds, and the reprocessability of the adhesive tape of the present invention is further improved.

[0115] On the other hand, when the aforementioned polyol compound is a polyol with a large number of carbon atoms, soft segments with low polarity can be obtained as structural units of the aforementioned urethane polymer. By including the aforementioned soft segments in the aforementioned urethane polymer, the degree of freedom of deformation of the resulting urethane polymer is further improved, resulting in a further improvement in the adhesive strength of the adhesive tape of the present invention.

[0116] From the viewpoint of excellent compatibility with the above-mentioned compound (C1) and vinyl monomer polymers having structural units derived from the above-mentioned compound (C1), the above-mentioned urethane polymer preferably contains the above-mentioned hard segments.

[0117] The method for manufacturing the aforementioned urethane polymer is not particularly limited; for example, it can be obtained by mixing and stirring a polyol compound with a polyisocyanate compound. It should be noted that the reaction between the polyol compound and the polyisocyanate compound can be carried out using any suitable method employed in the manufacture of the urethane polymer. Furthermore, in this reaction, an organic solvent (e.g., ethyl acetate, methyl ethyl ketone, chloroform, etc.) that does not possess reactive hydrogen atoms capable of reacting with isocyanate groups, and a catalyst (e.g., organometallic catalysts such as tin chloride and organotin compounds, organic bases such as tertiary amine compounds, organic acids such as acetic acid and acrylic acid, etc.) can be added as needed, and the reaction can then proceed.

[0118] Examples of the aforementioned polyol compounds include: polyester polyols (condensation polymers of diols with dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid), polyether polyols (polyether polyols obtained by addition polymerization of ethylene oxide, tetrahydrofuran, etc.), polyacrylate polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols or their hydrides, polyisoprene polyols or their hydrides, phenolic polyols, epoxy polyols, caprolactone polyols, and polysulfone polyols. Additionally, copolymer polyols such as polyester and polyether polyols can also be cited as examples of polyol compounds.

[0119] From the viewpoint of further improving the polarity of the obtained urethane polymer and its excellent compatibility with the aforementioned compound (C1) and vinyl monomer polymers having structural units derived from the aforementioned compound (C1), it is preferable to include at least one selected from polyether glycol, polyester glycol, and polycarbonate glycol. From the viewpoint of cohesive strength and compatibility with the aforementioned compound (C1) and vinyl monomer polymers having structural units derived from the aforementioned compound (C1), it is more preferable to include one selected from polyester glycol and polycarbonate glycol, and even more preferably to include polycarbonate glycol. That is, the aforementioned urethane polymer preferably has at least one selected from structural units derived from polyether glycol, structural units derived from polyester glycol, and structural units derived from polycarbonate glycol. Furthermore, the aforementioned urethane polymer is more preferably selected from structural units derived from polyester glycol and structural units derived from polycarbonate glycol, and the aforementioned urethane polymer is even more preferably selected from structural units derived from polycarbonate glycol.

[0120] These polyol compounds can be used in combination with one or more.

[0121] Examples of diol compounds used in the synthesis of the aforementioned polycarbonate diols include diol compounds in which the hydroxyl group has a valence of 2. Only one of these diol compounds may be used, or two or more may be used in combination.

[0122] The preferred lower limit for the content of the polycarbonate diol-derived structural units in the aforementioned urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. By making the content of the polycarbonate diol-derived structural units 3% by mass or more, the cohesive strength of the resulting urethane polymer is further improved, and the reprocessability of the adhesive tape of the present invention is further improved. By making the content of the polycarbonate diol-derived structural units 70% by mass or less, the degree of freedom of deformation of the resulting urethane polymer is further improved, resulting in a further improvement in the adhesive strength of the adhesive tape of the present invention. The more preferred lower limit for the content of the polycarbonate diol-derived structural units is 5% by mass, the more preferred upper limit is 60% by mass, the more preferably lower limit is 7% by mass, and the more preferably upper limit is 50% by mass.

[0123] The preferred lower limit for the content of the polyester diol-derived structural units in the aforementioned urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. By making the content of the polyester diol-derived structural units 3% by mass or more, the cohesive strength of the resulting urethane polymer is further improved, and the reprocessability of the adhesive tape of the present invention is further improved. By making the content of the polyester diol-derived structural units 70% by mass or less, the degree of freedom of deformation of the resulting urethane polymer is further improved, resulting in a further improvement in the adhesive strength of the adhesive tape of the present invention. The more preferred lower limit for the content of the polyester diol-derived structural units is 5% by mass, the more preferred upper limit is 60% by mass, the more preferably lower limit is 7% by mass, and the more preferably upper limit is 50% by mass.

[0124] The preferred lower limit for the content of the polyether diol-derived structural units in the aforementioned urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. By making the content of the polyether diol-derived structural units 3% by mass or more, the cohesive strength of the resulting urethane polymer is further improved, and the reprocessability of the adhesive tape of the present invention is further improved. By making the content of the polyether diol-derived structural units 70% by mass or less, the degree of freedom of deformation of the resulting urethane polymer is further improved, resulting in a further improvement in the adhesive strength of the adhesive tape of the present invention. The more preferred lower limit for the content of the polyether diol-derived structural units is 5% by mass, the more preferred upper limit is 60% by mass, the more preferably lower limit is 7% by mass, and the more preferably upper limit is 50% by mass.

[0125] Examples of urethane polymers having structural units derived from polyether diols include AG8451 (manufactured by Lubrizol).

[0126] From the viewpoint of the reprocessability of the adhesive tape of the present invention, the above-mentioned polyol compound may contain an alcohol compound having 3 or more hydroxyl groups.

[0127] Examples of the aforementioned polyisocyanate compounds include: diphenylmethane diisocyanate, toluene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated phenylmethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanate methyl)cyclohexane, and dicyclohexylmethane diisocyanate. Furthermore, modified forms of the aforementioned polyisocyanate compounds can be used as the polyisocyanate compounds. Examples of modified polyisocyanate compounds include: biuret-modified polyisocyanate compounds, isocyanurate-modified polyisocyanate compounds, adducts obtained by reacting the polyisocyanate compounds with glycerol, trimethylolpropane, or alkylene oxides such as propylene oxide and ethylene oxide, and polymethylene polyphenyl polyisocyanates, also known as polymeric MDI. From the viewpoint of excellent compatibility with the above-mentioned compound (C1) and vinyl monomer polymers having structural units derived from the above-mentioned compound (C1), higher reprocessability, and higher adhesive strength, polyisocyanate compounds containing aromatic groups are preferred, and more preferably, modified diphenylmethane diisocyanates such as diphenylmethane diisocyanate and liquid modified diphenylmethane diisocyanates.

[0128] These polyisocyanate compounds can be used in combination with one or more.

[0129] From the viewpoint of the reprocessability of the adhesive tape of the present invention, the above-mentioned polyisocyanate compound is preferably an isocyanate compound containing 3 or more isocyanate groups.

[0130] The preferred lower limit for the content of structural units derived from isocyanate compounds with 3 or more isocyanate groups in the above-mentioned urethane polymer is 0.1% by mass, and the preferred upper limit is 20% by mass. By ensuring that the content of the structural units derived from isocyanate compounds with 3 or more isocyanate groups is within the above-mentioned range, the adhesive tape of the present invention can achieve both higher adhesive strength and better reprocessability. A more preferred lower limit is 0.5% by mass, and a more preferred upper limit is 10% by mass.

[0131] The aforementioned urethane polymer preferably has structural units derived from compounds containing aromatic groups. By giving the aforementioned urethane polymer structural units derived from compounds containing aromatic groups, the reprocessability of the adhesive tape of the present invention is further improved.

[0132] Examples of compounds containing aromatic groups include, for example, the polyol compounds containing aromatic groups and the polyisocyanate compounds containing aromatic groups.

[0133] The preferred lower limit for the weight-average molecular weight (Mw) of the aforementioned urethane polymer is 3,000, and the preferred upper limit is 300,000. By making the weight-average molecular weight of the aforementioned urethane polymer 3,000 or higher, the reprocessability of the adhesive tape of the present invention is further improved. By making the weight-average molecular weight of the aforementioned urethane polymer 300,000 or lower, the adhesive strength of the adhesive tape of the present invention is further improved. The more preferred lower limit for the weight-average molecular weight of the aforementioned urethane polymer is 5,000, the more preferred upper limit is 250,000, the even more preferred lower limit is 7,000, and the even more preferred upper limit is 200,000.

[0134] Of the total 100 parts by mass of the vinyl monomer polymer and the urethane polymer, the preferred lower limit of the content of the urethane polymer is 5 parts by mass, and the preferred upper limit is 90 parts by mass.

[0135] By ensuring the content of the aforementioned urethane polymer is within the above-mentioned range, the adhesive tape of the present invention achieves both higher adhesive strength and superior reprocessability. A more preferred lower limit for the content of the aforementioned urethane polymer is 10 parts by mass, a more preferred upper limit is 70 parts by mass, a further preferred lower limit is 15 parts by mass, and a further preferred upper limit is 60 parts by mass.

[0136] In this specification, the crosslinked product refers to the product obtained by crosslinking the adhesive composition.

[0137] In the first configuration described above, in the crosslinked product described above, the vinyl monomer polymer and the urethane polymer are crosslinked by a crosslinking agent.

[0138] Furthermore, in the second configuration described above, it is preferable that the vinyl monomer polymer and the urethane polymer are cross-linked by a cross-linking agent in the cross-linked product.

[0139] Examples of crosslinking agents include isocyanate-based crosslinking agents, aziridine-based crosslinking agents, epoxy-based crosslinking agents, and metal chelate-type crosslinking agents. Among these, isocyanate-based crosslinking agents are preferred from the perspective of selective crosslinking of hydroxyl groups and easy control of the crosslinking structure.

[0140] Examples of isocyanate-based crosslinking agents include Coronate HX and Millionate MR200 (both manufactured by Tosoh Corporation).

[0141] The preferred lower limit for the crosslinking agent content in the total of the adhesive composition and the crosslinking agent is 0.1% by mass, and the preferred upper limit is 20% by mass. By making the crosslinking agent content 0.1% by mass or more, the adhesive can be further cured, and the reprocessability of the adhesive tape of the present invention is further improved. By making the crosslinking agent content 20% by mass or less, the adhesive does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength.

[0142] The adhesive described above may further contain a tackifying resin (tackifier). By including a tackifying resin in the adhesive, the adhesive strength of the adhesive tape of the present invention is further improved.

[0143] Examples of tackifying resins include rosin-based resins such as rosin ester resins, terpene-based resins such as terpene phenol resins, and petroleum-based resins. Among these, rosin-based resins and terpene phenol resins with high polarity and excellent compatibility with the aforementioned vinyl monomer polymers and urethane polymers are preferred.

[0144] These tackifying resins can be used alone or in combination of two or more.

[0145] The aforementioned rosin ester resins refer to resins obtained by esterifying rosin resins, disproportionated rosin resins, hydrogenated rosin resins, and dimers of resin acids such as rosin acid (polymerized rosin resins), which are mainly composed of rosin acid, with an alcohol. In this process, a portion of the hydroxyl groups of the alcohol used in the esterification is not used for esterification but is included within the resin, thereby adjusting the hydroxyl value to the aforementioned range. Examples of alcohols include ethylene glycol, glycerol, and pentaerythritol, among other polyols.

[0146] It should be noted that the resin obtained by esterifying rosin resin is rosin ester resin, the resin obtained by esterifying disproportionated rosin resin is disproportionated rosin ester resin, the resin obtained by esterifying hydrogenated rosin resin is hydrogenated rosin ester resin, and the resin obtained by esterifying polymerized rosin resin is polymerized rosin ester resin.

[0147] The above-mentioned terpene phenol resin is a resin obtained by polymerizing terpenes in the presence of phenol.

[0148] The preferred lower limit for the content of the tackifying resin in the above-mentioned adhesive is 1% by mass, and the preferred upper limit is 60% by mass. By making the content of the tackifying resin 1% by mass or more, the adhesive tape of the present invention can exhibit higher adhesive strength. By making the content of the tackifying resin 60% by mass or less, the adhesive strength of the adhesive tape of the present invention does not become excessively high, and the reprocessability is further improved. The more preferred lower limit for the content of the tackifying resin is 3% by mass, the more preferred upper limit is 50% by mass, the even more preferred lower limit is 5% by mass, and the even more preferred upper limit is 40% by mass.

[0149] The adhesives described above may, as needed, contain additives such as silane coupling agents, plasticizers, softeners, fillers, pigments, and dyes, without compromising the effectiveness of the present invention.

[0150] There are no particular limitations on the method for manufacturing the above-mentioned adhesive, and it can be manufactured by methods known in the past. Specifically, for example, it can be manufactured by adding urethane polymers, vinyl monomer polymers or the above-mentioned compound (C1), crosslinking agents, etc., to a solvent and then stirring thoroughly.

[0151] In addition, when the above-mentioned compound (C1) is (a) above, the adhesive can also be obtained by polymerization using the following method: mixing the above-mentioned monomer mixture, the above-mentioned photopolymerization initiator and the above-mentioned urethane polymer, applying it to a release PET film and a substrate using an applicator, sealing the upper surface after coating with a release PET film, or preventing the coated surface from contacting air under a nitrogen atmosphere, and then subjecting the substrate to UV irradiation.

[0152] In the first configuration described above, the preferred lower limit for the thickness of the adhesive layer is 50 μm. In the first configuration described above, when the thickness of the adhesive layer is 50 μm or more, the reprocessability of the adhesive tape of the present invention is further improved. A more preferred lower limit for the thickness of the adhesive layer is 60 μm, and a further preferred lower limit is 70 μm.

[0153] In the second configuration described above, the minimum thickness of the adhesive layer is 50 μm. In the second configuration, when the thickness of the adhesive layer is 50 μm or more, the reprocessability of the adhesive tape of the present invention is improved. A preferred minimum thickness of 60 μm is the adhesive layer, and a more preferred minimum thickness is 70 μm.

[0154] Furthermore, the preferred upper limit for the thickness of the adhesive layer is 300 μm. By keeping the thickness of the adhesive layer below 300 μm, the adhesive strength of the adhesive tape of the present invention becomes higher. A more preferred upper limit for the thickness of the adhesive layer is 250 μm, and a further preferred upper limit is 200 μm.

[0155] In the first configuration described above, the preferred lower limit of the tensile breaking stress of the adhesive layer at 23°C is 0.50 MPa. In the first configuration described above, by making the tensile breaking stress of the adhesive layer at 23°C 0.50 MPa or higher, the reprocessability of the adhesive tape of the present invention becomes more excellent. In the first configuration described above, a more preferred lower limit of the tensile breaking stress of the adhesive layer at 23°C is 0.60 MPa, and a further preferred lower limit is 0.70 MPa.

[0156] In the second configuration described above, the lower limit of the tensile breaking stress of the adhesive layer at 23°C is 0.50 MPa. In the second configuration described above, by making the tensile breaking stress of the adhesive layer at 23°C 0.50 MPa or higher, the reprocessability of the adhesive tape of the present invention becomes excellent. In the second configuration described above, the preferred lower limit of the tensile breaking stress of the adhesive layer at 23°C is 0.60 MPa, and a more preferred lower limit is 0.70 MPa.

[0157] Furthermore, the preferred upper limit for the tensile breaking stress of the adhesive layer at 23°C is 20 MPa. By setting the tensile breaking stress of the adhesive layer at 23°C to 20 MPa or less, the adhesive strength of the adhesive tape of the present invention is increased. A more preferred upper limit for the tensile breaking stress of the adhesive tape of the present invention at 23°C is 15 MPa, and a further preferred upper limit is 10 MPa.

[0158] The preferred lower limit for the elongation at break of the adhesive layer at 23°C is 300%. By achieving an elongation at break of 300% or more for the adhesive layer at 23°C, the reprocessability of the adhesive tape of the present invention becomes more excellent. A more preferred lower limit for the elongation at break of the adhesive layer at 23°C is 350%, and a further preferred lower limit is 400%.

[0159] Furthermore, the preferred upper limit for the elongation at break of the adhesive layer is 3000%. By making the elongation at break of the adhesive tape of the present invention 3000% or less, the adhesive force of the adhesive tape of the present invention becomes higher. A more preferred upper limit for the elongation at break of the adhesive tape of the present invention is 2500%, and a further preferred upper limit is 2000%.

[0160] The tensile stress at break and the elongation at break described above are determined, for example, by performing a tensile test according to JIS K7161 using a tensile testing machine (such as "TBS-1225S" manufactured by A&D Corporation), at 23°C, 50% RH, and a tensile speed of 200 mm / min, stretching the adhesive layer along its long side. The stress at which the adhesive layer breaks is then obtained as the tensile stress at break, and the ratio of the length of the long side of the adhesive layer at break to the length of the long side of the adhesive layer before the tensile test is obtained as the elongation at break. It should be noted that the length of the long side of the adhesive layer refers to the distance between the chucks of the tensile testing machine that hold the adhesive layer during the tensile test.

[0161] Methods for adjusting the tensile fracture stress to the aforementioned range include, for example, changing the composition of the vinyl monomer polymer or the urethane polymer; changing the type and content of the crosslinking agent; changing the type and content of additives such as tackifying resin; etc.

[0162] Specifically, examples include methods for increasing the glass transition temperature of the vinyl monomer and the urethane polymer by changing their composition.

[0163] Methods for adjusting the elongation at break to the above range include, for example, changing the composition of the vinyl monomer or the urethane polymer; changing the type and content of the crosslinking agent; changing the type and content of additives such as tackifying resin; etc.

[0164] Specifically, examples include increasing the proportion of the aforementioned urethane polymer in the crosslinked product.

[0165] The preferred lower limit of the shear storage modulus of the adhesive layer at 25°C is 0.05 MPa, and the preferred upper limit is 1.0 MPa. By making the shear storage modulus of the adhesive layer at 25°C 0.05 MPa or higher, the adhesive layer becomes harder, and the reprocessability of the adhesive tape of the present invention is further improved. By making the shear storage modulus of the adhesive layer at 25°C 1.0 MPa or lower, the adhesive tape of the present invention can exhibit higher adhesive strength. The more preferred lower limit of the shear storage modulus of the adhesive layer at 25°C is 0.07 MPa, the more preferred upper limit is 0.9 MPa, the even more preferred lower limit is 0.1 MPa, and the even more preferred upper limit is 0.8 MPa.

[0166] The adhesive layer preferably has only one peak of loss tangent (tanδ) in the temperature range of -10°C to 30°C when measured at a frequency of 1 Hz. When there is only one peak of loss tangent (tanδ) in the temperature range of -10°C to 30°C when measured at a frequency of 1 Hz, the adhesive layer is more uniform, resulting in better compatibility between the components in the adhesive layer. Therefore, the adhesive tape of the present invention can achieve both higher adhesive strength and better reprocessability.

[0167] It should be noted that in this specification, "one peak" means that the maximum value of the loss tangent (tanδ) is 1 in the temperature range of -10℃ to 30℃ in the spectrum of the loss tangent (tanδ) obtained by dynamic viscoelasticity measurement.

[0168] When the adhesive layer has only one peak in the temperature range of -10°C to 30°C when measured at a frequency of 1 Hz, the preferred upper limit of the half-width of the loss tangent peak (hereinafter sometimes simply referred to as "the half-width of the loss tangent peak") is 40°C. When the half-width of the loss tangent peak is 40°C or less, the adhesive layer is more uniform, resulting in better compatibility between the components of the adhesive layer. Therefore, the adhesive tape of the present invention can achieve both higher adhesion and better reprocessability. A more preferred upper limit of the half-width of the loss tangent peak is 35°C, and a further preferred upper limit is 30°C.

[0169] Furthermore, there is no particular limitation on the preferred lower limit of the half-width of the peak of the loss tangent mentioned above; in practice, the lower limit is about 5°C.

[0170] It should be noted that in this specification, "half-width of the peak of loss tangent" refers to the full width at half-peak of the peak of loss tangent.

[0171] The shear storage modulus of the adhesive layer at 25°C, the loss tangent (tanδ) in the temperature range of -10°C to 30°C when measured at a frequency of 1 Hz, and the half-width of the peak of the loss tangent (tanδ) when measured at a frequency of 1 Hz can be determined by dynamic viscoelasticity measurement.

[0172] Specifically, for the obtained adhesive layer, a dynamic viscoelastic spectrum is measured using a dynamic viscoelasticity measuring device (e.g., IT Measurement & Control Co., Ltd., "DVA-200") under a nitrogen atmosphere, at a shear direction, a frequency of 1 Hz, a heating rate of 10 °C / min, and a temperature range of -50 °C to 150 °C. This allows the determination of the shear storage modulus at 25 °C and the peak of the loss tangent (tanδ) measured at a frequency of 1 Hz. Furthermore, the half-width of the loss tangent (tanδ) peak can be calculated from the obtained loss tangent (tanδ) spectrum.

[0173] It should be noted that when the thickness of the adhesive layer is less than 500 μm, an adhesive layer for testing is prepared by laminating adhesive layers in a manner that makes the thickness 500 μm or more, and dynamic viscoelasticity is measured.

[0174] As a method to adjust the shear storage modulus of the adhesive layer at 25°C and the half-width of the peak of the loss tangent (tanδ) of the adhesive layer at a frequency of 1 Hz to the above range, examples include: changing the composition of the vinyl monomer polymer and the urethane polymer, changing the type and content of the crosslinking agent, etc.

[0175] Specifically, for example, to reduce the shear storage modulus of the adhesive layer at 25°C, one method is to increase the proportion of structural units in the vinyl monomer polymer derived from (meth)acrylate monomers with low glass transition temperatures during homopolymer formation. On the other hand, to increase the shear storage modulus of the adhesive layer at 25°C, one method is to increase the proportion of structural units in the vinyl monomer polymer derived from (meth)acrylate monomers with high glass transition temperatures during homopolymer formation.

[0176] It should be noted that, in this specification, "glass transition temperature when preparing homopolymers" refers to the glass transition temperature obtained by differential scanning calorimetry (DSC) measurement of homopolymers made from (meth)acrylates with a weight-average molecular weight of 100,000 or more and 2,000,000 or less. Furthermore, examples of methods for determining the glass transition temperature when preparing the aforementioned homopolymers include: under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min), using a differential scanning calorimeter (Seiko Instruments, "220C", etc.), and following the method according to JIS K6240:2011, at a measurement temperature of -100°C to 200°C and a heating rate of 10°C / min.

[0177] As a method to adjust the half-width of the peak of the loss tangent (tanδ) of the above-mentioned adhesive layer when measured at a frequency of 1 Hz to the above-mentioned range, examples include: changing the composition of the above-mentioned vinyl monomer polymer and the above-mentioned urethane polymer; changing the type and content of the above-mentioned crosslinking agent, etc.

[0178] The preferred lower limit for the gel content of the adhesive layer is 30% by mass, and the preferred upper limit is 99% by mass. By making the gel content of the adhesive layer 30% by mass or more, the adhesive layer becomes harder, and the reprocessability of the adhesive tape of the present invention is further improved. By making the gel content of the adhesive layer 99% by mass or less, the adhesive tape of the present invention can exert higher adhesive strength. The more preferred lower limit for the gel content of the adhesive layer is 32% by mass, the more preferred upper limit is 90% by mass, the even more preferred lower limit is 35% by mass, and the even more preferred upper limit is 80% by mass.

[0179] It should be noted that the gel fraction of the above adhesive layer was determined by the following method.

[0180] Specifically, firstly, a test piece is prepared by cutting the adhesive tape with the aforementioned adhesive layer into a planar square shape with a width of 30 mm and a length of 30 mm. The test piece is then immersed in tetrahydrofuran (THF) at 23°C for 24 hours, filtered through a metal mesh, and dried at 110°C for 1 hour. The mass of the dried test piece is measured, and the gel fraction is calculated using the following formula (I). It should be noted that no release film for protecting the aforementioned adhesive layer is laminated on the test piece. Furthermore, when the adhesive tape does not have a substrate, W0 is set to 0 for calculating the gel fraction.

[0181] Gel fraction (mass%) = 100 × (W2 - W0) / (W1 - W0) (I)

[0182] (W0: quality of the substrate, W1: quality of the test piece before impregnation, W2: quality of the test piece after impregnation and drying)

[0183] Methods for adjusting the gel fraction of the adhesive layer to the aforementioned range include, for example, changing the composition of the vinyl monomer polymer and the urethane polymer; changing the type and content of the crosslinking agent; and changing the type and content of additives such as tackifying resin.

[0184] The preferred lower limit of the Young's modulus of the adhesive layer at 23°C is 0.010 MPa, and the preferred upper limit is 10 MPa. By making the Young's modulus of the adhesive layer at 23°C 0.010 MPa or higher, a greater tensile stress is applied during peeling of the adhesive tape of the present invention, thereby further improving the reprocessability of the adhesive tape of the present invention. By making the Young's modulus of the adhesive layer at 23°C 10 MPa or lower, the adhesive layer does not become too stiff, and the adhesive force of the adhesive tape of the present invention becomes higher. The more preferred lower limit of the Young's modulus of the adhesive layer at 23°C is 0.012 MPa, the more preferred upper limit is 7 MPa, the further preferred lower limit is 0.014 MPa, and the further preferred upper limit is 5 MPa.

[0185] It should be noted that, for example, the following methods can be used to determine the Young's modulus of the aforementioned adhesive layer.

[0186] That is, by performing the tensile test described above on the adhesive layer to measure the tensile fracture stress and elongation at break, the slope in the linear region (elastic region) of the obtained stress-strain curve (SS curve) can be calculated, and the Young's modulus of the adhesive layer can be obtained according to this method.

[0187] As a method for adjusting the Young's modulus of the adhesive layer at 23°C to the above-mentioned range, examples include: changing the composition of the vinyl monomer polymer and the urethane polymer; changing the type and content of the crosslinking agent; changing the type and content of additives such as tackifying resin, etc.

[0188] The adhesive tape of the present invention can be a non-supported adhesive tape without a substrate, or a supported adhesive tape with an adhesive layer formed on a substrate. It should be noted that when the adhesive tape of the present invention has a substrate, the adhesive tape only needs to have the adhesive layer on at least one side of the substrate; that is, it can be a single-sided adhesive tape with the adhesive layer on one side of the substrate, or a double-sided adhesive tape with the adhesive layer on both sides of the substrate.

[0189] When the adhesive tape of the present invention has a substrate, the aforementioned substrate is not particularly limited, and examples include: resin sheets or resin films formed from resins such as acrylic acid, olefins, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), nylon, urethane, and polyimide; sheets or films with a mesh structure; and sheets or films with openings (foam sheets, foam films), etc. Among these, from the viewpoint of improving stress relief and height difference tracking, the aforementioned substrate preferably includes foam substrates such as foam sheets and foam films.

[0190] If the above-mentioned adhesive is used, an adhesive tape with excellent reprocessability can be obtained even when using foam substrates such as foam sheets that are prone to breakage during reprocessing as the substrate.

[0191] The preferred lower limit for the thickness of the aforementioned substrate is 5 μm, and the preferred upper limit is 1000 μm. If the thickness of the substrate is within this range, an adhesive tape with moderate stiffness and excellent processability can be produced. A more preferred lower limit for the thickness of the aforementioned substrate is 10 μm, a more preferred upper limit is 500 μm, a further preferred upper limit is 200 μm, and an even more preferred upper limit is 150 μm.

[0192] The manufacturing method of the adhesive tape of the present invention is not particularly limited, and it can be manufactured by conventionally known manufacturing methods. For example, in the case of a double-sided adhesive tape having a substrate, the following methods can be cited.

[0193] First, a solution of adhesive a is obtained by adding vinyl monomer polymer, urethane polymer, crosslinking agent, and tackifying resin as needed, and stirring thoroughly. The obtained adhesive a is then applied to one side of a substrate, and the solvent in the solution is completely dried to form adhesive layer a. Next, a release film is overlapped onto the formed adhesive layer a with its release-treated surface facing the adhesive layer a. It should be noted that when the compound (C1) is (a) as described above, polymerization can be carried out using the following method to obtain the adhesive while forming the adhesive layer: the monomer mixture, the photopolymerization initiator, the urethane polymer, and the crosslinking agent as needed are mixed, applied to a release PET film using an applicator, and the coated upper surface is sealed with the release PET film, or the coated surface is kept out of contact with air under a nitrogen atmosphere and then subjected to UV irradiation on the substrate.

[0194] Next, prepare another release film besides the aforementioned release film. Apply a solution of adhesive b, prepared using the same method as described above, to the release treatment surface of this release film. Completely dry and remove the solvent from the solution, thereby creating a laminated film with adhesive layer b formed on the surface of the release film. Overlap the resulting laminated film with adhesive layers b facing each other onto the other side of a substrate on which adhesive layer a is formed, to create a laminate. Then, by applying pressure to the laminated film using a rubber roller or the like, a double-sided adhesive tape can be obtained, in which adhesive layers are formed on both sides of the substrate and the surfaces of the adhesive layers are covered by the release film.

[0195] Alternatively, two sets of laminated films can be made using the same method. These laminated films are then overlapped on both sides of the substrate with the adhesive layer of the laminated film facing the substrate, respectively, to create a laminate. The laminate is then pressed using a rubber roller or the like, thereby obtaining a double-sided adhesive tape with adhesive layers on both sides of the substrate and the surface of the adhesive layers being covered by a release film.

[0196] In the first configuration described above, the preferred lower limit of the 180° peel force of the adhesive tape of the present invention against SUS at 23°C and a peel speed of 300 mm / min is 5.0 N / inch, and the preferred upper limit is 30.0 N / inch. By ensuring that the 180° peel force of the adhesive tape of the present invention against SUS at 23°C and a peel speed of 300 mm / min is within the above range, the adhesive tape of the present invention can achieve both higher adhesive strength and better reprocessability. A more preferred lower limit of the 180° peel force of the adhesive tape of the present invention against SUS at 23°C and a peel speed of 300 mm / min is 7.0 N / inch, a more preferred upper limit is 25.0 N / inch, a further preferred lower limit is 10.0 N / inch, and a further preferred upper limit is 20.0 N / inch.

[0197] In the second configuration described above, the adhesive tape of the present invention exhibits a lower limit of 5.0 N / inch and an upper limit of 30.0 N / inch for 180° peel force against SUS at 23°C and a peel speed of 300 mm / min. By ensuring that the adhesive tape of the present invention exhibits a 180° peel force against SUS at 23°C and a peel speed of 300 mm / min within the above range, the adhesive tape of the present invention can achieve both higher adhesive strength and better reprocessability. The preferred lower limit of the adhesive tape of the present invention for 180° peel force against SUS at 23°C and a peel speed of 300 mm / min is 7.0 N / inch, the preferred upper limit is 25.0 N / inch, the more preferred lower limit is 10.0 N / inch, and the more preferred upper limit is 20.0 N / inch.

[0198] It should be noted that the aforementioned determination of the 180° peel force of SUS at 23°C and a peel speed of 300 mm / min can be performed, for example, by using a tensile testing machine (such as the "RTI-1310" manufactured by A&D Corporation) according to JIS Z0237, at 23°C, 50% RH, a peel speed of 300 mm / min, and a peel angle of 180°. Furthermore, in the case where the adhesive tape of the present invention is a non-supported type adhesive tape without a substrate, or in the case where the adhesive tape of the present invention is a double-sided adhesive tape with a substrate, a test piece is prepared by backing the side of the adhesive tape where the 180° peel force is not measured with a PET film or the like, and a peel test is performed using the prepared test piece.

[0199] As a method for adjusting the 180° peel force of SUS at 23°C and a peel speed of 300 mm / min to the above-mentioned range, examples include: changing the composition of the vinyl monomer polymer and the urethane polymer; changing the type and content of the crosslinking agent; changing the type and content of additives such as tackifying resin; and increasing the glass transition temperature of the adhesive in the range of 25°C or below.

[0200] The adhesive tape of the present invention is not particularly limited in its application, but is preferably used for fixing electronic components or automotive components. Specifically, the adhesive tape of the present invention can be suitably used for fixing electronic components in large portable electronic devices, fixing automotive components (e.g., automotive panels), etc.

[0201] An adhesive composition containing a vinyl monomer polymer and a urethane polymer, wherein the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from (a), (b) or (c) below, is also one of the present inventions.

[0202] (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms

[0203] (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms.

[0204] (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

[0205] The adhesive composition of the present invention can simultaneously exhibit high adhesion and excellent reprocessability.

[0206] In the adhesive composition of the present invention, the above-mentioned vinyl monomer polymer has structural units derived from compounds (C1) selected from (a), (b) or (c) below.

[0207] (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms

[0208] (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms.

[0209] (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

[0210] The aforementioned compound (C1) exhibits excellent compatibility with urethane polymers. Therefore, in the adhesive composition of the present invention, by having the aforementioned vinyl monomer polymer possess structural units derived from compound (C1) selected from (a), (b), or (c) above, the aforementioned vinyl monomer polymer exhibits excellent compatibility with the urethane polymer described later. Consequently, the crosslinking of the aforementioned compound (C1) and the vinyl monomer polymer having structural units derived from the aforementioned compound (C1) with the urethane polymer described later proceeds uniformly. As a result, the crosslinking product contained in the adhesive obtained from the adhesive composition of the present invention has both a vinyl monomer polymer structure and a urethane polymer structure, and the adhesive obtained from the adhesive composition of the present invention can achieve both high adhesion and excellent reprocessability. Furthermore, by ensuring excellent compatibility between the aforementioned compound (C1) and the aforementioned urethane polymer, the adhesive obtained from the adhesive composition of the present invention can suppress interface formation caused by microphase separation, making the resin less prone to breakage during stretching, resulting in excellent reprocessability.

[0211] Examples of aromatic (meth)acrylates in the adhesive composition of the present invention include: benzyl acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol acrylate, methylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and 2-([1,1'-biphenyl]-2-oxy)ethyl (meth)acrylate. From the viewpoint of adhesive properties, phenoxyethyl (meth)acrylate and phenoxydiethylene glycol acrylate are preferred.

[0212] In the adhesive composition of the present invention, the preferred lower limit of the content of the structural units derived from aromatic (meth)acrylates in the total vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass. By making the content of the structural units derived from aromatic (meth)acrylates 5% by mass or more, the adhesive obtained from the adhesive composition of the present invention becomes harder, and thus its reprocessability is further improved. By making the content of the structural units derived from aromatic (meth)acrylates 95% by mass or less, the adhesive obtained from the adhesive composition of the present invention does not become too hard and can exhibit higher adhesive strength. The more preferred lower limit of the content of the structural units derived from aromatic (meth)acrylates 10% by mass, the more preferred upper limit is 90% by mass, the further preferred lower limit is 15% by mass, and the further preferred upper limit is 85% by mass.

[0213] Examples of nitrogen-containing (meth)acrylates in the adhesive composition of the present invention include (meth)acrylates containing urethane bonds, (meth)acrylates containing imide bonds, and (meth)acrylamide. From the viewpoint of superior compatibility with urethane polymers described later, the nitrogen-containing (meth)acrylate preferably comprises at least one selected from (meth)acrylates containing urethane bonds and (meth)acrylates containing imide bonds, and more preferably comprises (meth)acrylates containing urethane bonds.

[0214] Examples of (meth)acrylates containing urethane bonds include 2-acrylate-2-[[(butylamino)-carbonyl]oxo]ethyl ester.

[0215] Examples of the above-mentioned (meth)acrylates containing imide bonds include N-[2-(acryloyloxy)ethyl]phthalimide.

[0216] In the adhesive composition of the present invention, the preferred lower limit of the content of the nitrogen-containing (meth)acrylate structural units in the total vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass. By making the content of the nitrogen-containing (meth)acrylate structural units at 5% by mass or more, the adhesive obtained from the adhesive composition of the present invention becomes harder, and thus its reprocessability is further improved. By making the content of the nitrogen-containing (meth)acrylate structural units at 95% by mass or less, the adhesive obtained from the adhesive composition of the present invention does not become too hard and can exhibit higher adhesive strength. The more preferred lower limit of the content of the nitrogen-containing (meth)acrylate structural units is 10% by mass, the more preferred upper limit is 90% by mass, the further preferred lower limit is 15% by mass, and the further preferred upper limit is 85% by mass.

[0217] In the adhesive composition of the present invention, of the total 100 parts by mass of the above-mentioned structural units derived from aromatic (meth)acrylates and structural units derived from nitrogen-containing (meth)acrylates, the preferred lower limit of the content of the structural units derived from aromatic (meth)acrylates is 5 parts by mass, and the preferred upper limit is 95 parts by mass. By keeping the content of the structural units derived from aromatic (meth)acrylates within the above range, the compatibility of the above-mentioned compound (C1) and the vinyl monomer polymer having the structural units derived from the above-mentioned compound (C1) with the urethane polymer described later becomes more excellent. Therefore, the adhesive obtained from the adhesive composition of the present invention can achieve both higher adhesive strength and better reprocessability. The more preferred lower limit of the content of the structural units derived from aromatic (meth)acrylates is 10 parts by mass, the more preferred upper limit is 90 parts by mass, the further preferred lower limit is 15 parts by mass, and the further preferred upper limit is 85 parts by mass.

[0218] The vinyl monomer polymer in the adhesive composition of the present invention preferably further has structural units derived from hydroxyl-containing (meth)acrylates.

[0219] By incorporating structural units derived from hydroxyl-containing (meth)acrylates into the aforementioned vinyl monomer polymer, crosslinking of the aforementioned compound (C1) with the subsequently described urethane polymer, induced by the crosslinking agent, becomes easier. As a result, the adhesive composition of the present invention is further cured, thus further improving the tensile strength and the reprocessability of the adhesive obtained from the adhesive composition of the present invention.

[0220] It should be noted that, in this specification, the structural unit derived from (meth)acrylate containing aromatic groups and hydroxyl groups is the structural unit derived from (meth)acrylate containing aromatic groups.

[0221] Furthermore, in this specification, the structural units derived from (meth)acrylates containing nitrogen atoms and hydroxyl groups are structural units derived from (meth)acrylates containing nitrogen atoms.

[0222] Examples of the hydroxyl-containing (meth)acrylates used in the adhesive composition of the present invention include: 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, tetrahydroxyfurfuryl (meth)acrylate, etc.

[0223] In the adhesive composition of the present invention, the preferred lower limit of the content of the structural units derived from hydroxyl-containing (meth)acrylate in the total vinyl monomer polymer is 0.01% by mass, and the preferred upper limit is 20% by mass. By making the content of the structural units derived from hydroxyl-containing (meth)acrylate 0.01% by mass or more, the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. By making the content of the structural units derived from hydroxyl-containing (meth)acrylate 20% by mass or less, the adhesive obtained from the adhesive composition of the present invention does not become too hard, and the adhesive can exert higher adhesive strength. The more preferred lower limit of the content of the structural units derived from hydroxyl-containing (meth)acrylate is 0.1% by mass, the more preferred upper limit is 10% by mass, the more preferably lower limit is 0.5% by mass, and the more preferably upper limit is 5.0% by mass.

[0224] The vinyl monomer polymer in the adhesive composition of the present invention may further have structural units derived from alkyl (meth)acrylates.

[0225] Examples of the alkyl methacrylates used in the adhesive compositions of the present invention include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, n-heptyl methacrylate, 2-ethylhexyl methacrylate, 2-octyl methacrylate, isooctyl methacrylate, n-nonyl methacrylate, isononyl methacrylate, lauryl methacrylate, myristyl methacrylate, cetyl methacrylate, isostearyl acrylate, and eicosyl methacrylate. From the viewpoint of compatibility with the urethane polymers described later, alkyl methacrylates with short alkyl chains are preferred; specifically, n-butyl methacrylate and 2-ethylhexyl methacrylate are preferred.

[0226] The vinyl monomer polymer in the adhesive composition of the present invention may further have structural units derived from (meth)acrylates containing aromatic groups, (meth)acrylates containing nitrogen atoms, (meth)acrylates containing hydroxyl groups, and other monomers other than the structural units derived from alkyl (meth)acrylates.

[0227] In the adhesive composition of the present invention, when the vinyl monomer polymer has structural units derived from (b) above, the preferred lower limit of the weight-average molecular weight (Mw) of the polymer having structural units derived from aromatic (meth)acrylates and structural units derived from nitrogen-containing (meth)acrylates is 200,000, and the preferred upper limit is 2,000,000. By making the weight-average molecular weight of the polymer having structural units derived from aromatic (meth)acrylates and structural units derived from nitrogen-containing (meth)acrylates 200,000 or more, the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. By making the weight-average molecular weight of the polymer having structural units derived from aromatic (meth)acrylates and structural units derived from nitrogen-containing (meth)acrylates 2,000,000 or less, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved. The preferred lower limit for the weight-average molecular weight of the polymer having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms is 400,000, the preferred upper limit is 1,500,000, the further preferred lower limit is 600,000, and the further preferred upper limit is 1,000,000.

[0228] In the adhesive composition of the present invention, when the vinyl monomer polymer has structural units derived from (c) above, the preferred lower limit of the weight-average molecular weight (Mw) of the polymer having structural units derived from (meth)acrylate containing aromatic groups is 200,000, and the preferred upper limit is 2,000,000. By making the weight-average molecular weight of the polymer having structural units derived from (meth)acrylate containing aromatic groups 200,000 or more, the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. By making the weight-average molecular weight of the polymer having structural units derived from (meth)acrylate containing aromatic groups 2,000,000 or less, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved. The more preferred lower limit of the weight-average molecular weight of the polymer having structural units derived from (meth)acrylate containing aromatic groups is 400,000, the more preferred upper limit is 1,500,000, the further preferred lower limit is 600,000, and the further preferred upper limit is 1,000,000.

[0229] In the adhesive composition of the present invention, when the vinyl monomer polymer has structural units derived from (c) above, the preferred lower limit of the weight-average molecular weight (Mw) of the polymer having structural units derived from nitrogen-containing (meth)acrylate is 200,000, and the preferred upper limit is 2,000,000. By making the weight-average molecular weight of the polymer having structural units derived from nitrogen-containing (meth)acrylate more than 200,000, the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. By making the weight-average molecular weight of the polymer having structural units derived from nitrogen-containing (meth)acrylate less than 2,000,000, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved. The more preferred lower limit of the weight-average molecular weight of the polymer having structural units derived from nitrogen-containing (meth)acrylate is 400,000, the more preferred upper limit is 1,500,000, the further preferred lower limit is 600,000, and the further preferred upper limit is 1,000,000.

[0230] When the compound (C1) in the adhesive composition of the present invention is (b) or (c) as described above, the method for manufacturing the vinyl monomer polymer can be, for example, by polymerizing a mixture of monomers, such as the aromatic (meth)acrylate, the nitrogen-containing (meth)acrylate, the hydroxyl-containing (meth)acrylate, the alkyl (meth)acrylate, and other monomers as required, in the presence of a polymerization initiator through a free radical reaction.

[0231] As a method for polymerizing the above-mentioned monomer mixture, conventionally known methods can be used, such as solution polymerization (boiling point polymerization or isothermal polymerization), UV polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, etc. Among these, solution polymerization and UV polymerization are preferred from the viewpoint that the adhesive obtained from the adhesive composition of the present invention has higher adhesive strength.

[0232] When solution polymerization is used as the method for polymerizing the above-mentioned monomer mixture, examples of reaction solvents include ethyl acetate, toluene, methyl ethyl ketone, dimethyl sulfoxide, ethanol, acetone, and diethyl ether. These reaction solvents can be used alone or in combination of two or more.

[0233] Examples of polymerization initiators include azo compounds and organic peroxides in the case of solution polymerization, and photopolymerization initiators such as benzophenone compounds, acetophenone compounds, alkyl phenyl ketone compounds, acylphosphine oxide compounds, dicenecene compounds, oxime ester compounds, benzoin ether compounds, and thioxanone in the case of UV polymerization.

[0234] Examples of the aforementioned azo compounds include: 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylpentanitrile), 2,2'-azobis(4-methoxy-2,4-dimethylpentanitrile), 1,1-azobis(cyclohexane-1-carboxylonitrile), 1-((1-cyano-1-methylethyl)azo)formamide, 4,4'-azobis(4-cyanopentanoic acid), dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis(2-methyl-N-(1,1'-bis(hydroxymethyl)-2-hydroxyethyl)propionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2'-azobis(2-azobis(2-methyl ... Bis(N-(2-propenyl)-2-methylpropionamide), 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis(2-(2-imidazolin-2-yl)propane) dihydrochloride, 2,2'-azobis(2-(1-(2-hydroxyethyl)-2-imidazolin-2-yl)propane) dihydrochloride Salts, 2,2'-azobis(2-(2-imidazolin-2-yl)propane), 2,2'-azobis(2-amidinylpropane) dihydrochloride, 2,2'-azobis(N-(2-carboxyethyl)-2-methylpropanediamine) tetrahydrate, 2,2'-azobis(1-imino-1-pyrrolyl-2-methylpropane) dihydrochloride, 2,2'-azobis(2,4,4-trimethylpentane), etc. These azo compounds can be used alone or in combination of two or more.

[0235] Examples of the aforementioned organic peroxides include: 1,1-bis(tert-hexylperoxide)-3,3,5-trimethylcyclohexane, tert-hexyl peroxypentanoate, tert-butyl peroxypentanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxide)hexane, tert-hexyl peroxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-3,5,5-trimethylhexanoate, and tert-butyl peroxylaurate. These organic peroxides can be used alone or in combination of two or more.

[0236] Examples of photopolymerization initiators include: Omnirad 184, Omnirad 369, Omnirad 379, Omnirad 379EG, Omnirad 651, Omnirad 784, Omnirad 819, Omnirad 907, Omnirad 2959, Omnirad TPO (all manufactured by IGM Resins), Omnirad OXE01 (manufactured by BASF), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.). These photopolymerization initiators can be used alone or in combination of two or more.

[0237] The urethane polymer in the adhesive composition of the present invention is a compound obtained by reacting a polyol compound with a polyisocyanate compound.

[0238] When the aforementioned polyol compound is a polyol diol with a small number of carbon atoms, a highly polar hard segment can be obtained as the structural unit of the aforementioned urethane polymer. By including the aforementioned hard segment in the aforementioned urethane polymer, the cohesive strength of the resulting urethane polymer is further improved through physical crosslinking via hydrogen bonds, and the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved.

[0239] On the other hand, when the aforementioned polyol compound is a polyol with a large number of carbon atoms, soft segments with low polarity can be obtained as structural units of the aforementioned urethane polymer. By including the aforementioned soft segments in the aforementioned urethane polymer, the degree of freedom of deformation of the obtained urethane polymer is further improved, resulting in a further improvement in the adhesive strength of the adhesive obtained from the adhesive composition of the present invention.

[0240] From the viewpoint of excellent compatibility with the above-mentioned compound (C1) and vinyl monomer polymers having structural units derived from the above-mentioned compound (C1), the above-mentioned urethane polymer preferably contains the above-mentioned hard segments.

[0241] The method for manufacturing the above-mentioned urethane polymer in the adhesive composition of the present invention is not particularly limited. For example, it can be obtained by mixing and stirring a polyol compound with a polyisocyanate compound. It should be noted that the reaction between the polyol compound and the polyisocyanate compound can be carried out by any suitable method used in the manufacture of the urethane polymer. In addition, in this reaction, an organic solvent (e.g., ethyl acetate, methyl ethyl ketone, chloroform, etc.) that does not have reactive hydrogen that can react with isocyanate groups can be added as needed, and a catalyst (e.g., organometallic catalysts such as tin chloride and organotin compounds, organic bases such as tertiary amine compounds, organic acids such as acetic acid and acrylic acid, etc.) can be added and the reaction can be carried out.

[0242] Examples of the polyol compounds used in the adhesive compositions of the present invention include: polyester polyols (condensation polymers of diols with dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid), polyether polyols (polyether polyols obtained by addition polymerization of ethylene oxide, tetrahydrofuran, etc.), polyacrylate polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols or their hydrogenated forms, polyisoprene polyols or their hydrogenated forms, phenolic polyols, epoxy polyols, caprolactone polyols, and polysulfone polyols. Additionally, copolymer polyols such as polyester / polyether polyols can also be cited as examples of polyol compounds.

[0243] From the viewpoint of further improving the polarity of the obtained urethane polymer and its excellent compatibility with the aforementioned compound (C1) and vinyl monomer polymers having structural units derived from the aforementioned compound (C1), it is preferable to include at least one selected from polyether glycol, polyester glycol, and polycarbonate glycol. From the viewpoint of cohesive strength and compatibility with the aforementioned compound (C1) and vinyl monomer polymers having structural units derived from the aforementioned compound (C1), it is more preferable to include one selected from polyester glycol and polycarbonate glycol, and even more preferably to include polycarbonate glycol. That is, the aforementioned urethane polymer preferably has at least one selected from structural units derived from polyether glycol, structural units derived from polyester glycol, and structural units derived from polycarbonate glycol. Furthermore, the aforementioned urethane polymer is more preferably selected from structural units derived from polyester glycol and structural units derived from polycarbonate glycol, and the aforementioned urethane polymer is even more preferably selected from structural units derived from polycarbonate glycol.

[0244] These polyol compounds can be used in combination with one or more.

[0245] The diol compounds used in the synthesis of the polycarbonate diols in the adhesive compositions of the present invention include, for example, diol compounds in which the hydroxyl group has a valence of 2. Only one of these diol compounds may be used, or two or more may be used in combination.

[0246] In the adhesive composition of the present invention, the preferred lower limit of the content of the polycarbonate diol-derived structural units in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. By making the content of the polycarbonate diol-derived structural units 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. By making the content of the polycarbonate diol-derived structural units 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved. The more preferred lower limit of the content of the polycarbonate diol-derived structural units is 5% by mass, the more preferred upper limit is 60% by mass, the more preferably lower limit is 7% by mass, and the more preferably upper limit is 50% by mass.

[0247] The preferred lower limit for the content of the polyester diol-derived structural units in the aforementioned urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. By making the content of the polyester diol-derived structural units 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. By making the content of the polyester diol-derived structural units 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved. The more preferred lower limit for the content of the polyester diol-derived structural units is 5% by mass, the more preferred upper limit is 60% by mass, the more preferably lower limit is 7% by mass, and the more preferably upper limit is 50% by mass.

[0248] In the adhesive composition of the present invention, the preferred lower limit of the content of the polyether diol-derived structural units in the above-mentioned urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. By making the content of the polyether diol-derived structural units 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. By making the content of the polyether diol-derived structural units 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved. The more preferred lower limit of the content of the polyether diol-derived structural units is 5% by mass, the more preferred upper limit is 60% by mass, the more preferably lower limit is 7% by mass, and the more preferably upper limit is 50% by mass.

[0249] Examples of urethane polymers having structural units derived from polyether glycols as used in the adhesive compositions of the present invention include, for example, AG8451 (manufactured by Lubrizol).

[0250] From the viewpoint of the reprocessability of the adhesive obtained from the adhesive composition of the present invention, the above-mentioned polyol compound may contain an alcohol compound having 3 or more hydroxyl groups.

[0251] Examples of the polyisocyanate compounds used in the adhesive compositions of the present invention include: diphenylmethane diisocyanate, toluene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornene diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated phenylmethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanate methyl)cyclohexane, dicyclohexylmethane diisocyanate, etc. Furthermore, modified forms of the aforementioned polyisocyanate compounds can be used as the polyisocyanate compounds. Examples of modified polyisocyanate compounds include: biuret-modified polyisocyanate compounds, isocyanurate-modified polyisocyanate compounds, adducts obtained by reacting the polyisocyanate compounds with glycerol, trimethylolpropane, or alkylene oxides such as propylene oxide and ethylene oxide, and polymethylene polyphenyl polyisocyanates, also known as polymeric MDI. From the viewpoint of excellent compatibility with the above-mentioned compound (C1) and vinyl monomer polymers having structural units derived from the above-mentioned compound (C1), superior reprocessability, and higher adhesive strength, polyisocyanate compounds containing aromatic groups are preferred. More preferably are modified diphenylmethane diisocyanates, liquid modified diphenylmethane diisocyanates, etc. Only one of these polyisocyanate compounds may be used, or two or more may be used in combination.

[0252] In the adhesive composition of the present invention, from the viewpoint of the reprocessability of the adhesive obtained from the adhesive composition of the present invention, the above-mentioned polyisocyanate compound preferably contains an isocyanate compound having an isocyanate group number of 3 or more.

[0253] In the adhesive composition of the present invention, the preferred lower limit of the content of structural units of isocyanate compounds with 3 or more isocyanate groups in the above-mentioned urethane polymer is 0.1% by mass, and the preferred upper limit is 20% by mass. By ensuring that the content of the structural units of isocyanate compounds with 3 or more isocyanate groups is within the above-mentioned range, the adhesive obtained from the adhesive composition of the present invention can achieve both higher adhesive strength and better reprocessability. A more preferred lower limit is 0.5% by mass, and a more preferred upper limit is 10% by mass.

[0254] In the adhesive composition of the present invention, the urethane polymer preferably has structural units derived from compounds containing aromatic groups. By giving the urethane polymer structural units derived from compounds containing aromatic groups, the reprocessability of the adhesive of the present invention is further improved.

[0255] Examples of compounds containing aromatic groups include, for example, the polyol compounds containing aromatic groups and the polyisocyanate compounds containing aromatic groups.

[0256] In the adhesive composition of the present invention, the preferred lower limit of the weight-average molecular weight (Mw) of the above-mentioned urethane polymer is 3,000, and the preferred upper limit is 300,000. By making the weight-average molecular weight of the above-mentioned urethane polymer 3,000 or more, the reprocessability of the adhesive of the present invention is further improved. By making the weight-average molecular weight of the above-mentioned urethane polymer 300,000 or less, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved. A more preferred lower limit of the weight-average molecular weight of the above-mentioned urethane polymer is 5,000, a more preferred upper limit is 250,000, a further preferred lower limit is 7,000, and a further preferred upper limit is 200,000.

[0257] In the adhesive composition of the present invention, the preferred lower limit of the content of the urethane polymer in 100 parts by weight of the total vinyl monomer polymer and the urethane polymer is 5 parts by weight, and the preferred upper limit is 90 parts by weight.

[0258] By keeping the content of the urethane polymer within the aforementioned range, the adhesive obtained from the adhesive composition of the present invention can achieve both higher adhesive strength and better reprocessability. A more preferred lower limit for the content of the urethane polymer is 10 parts by mass, a more preferred upper limit is 70 parts by mass, a further preferred lower limit is 15 parts by mass, and a further preferred upper limit is 60 parts by mass.

[0259] In the adhesive composition of the present invention, where the urethane polymer and the vinyl monomer polymer are crosslinked in the crosslinked product by a crosslinking agent, examples of such crosslinking agents include isocyanate-based crosslinking agents, aziridine-based crosslinking agents, epoxy-based crosslinking agents, and metal chelate-type crosslinking agents. Among these, isocyanate-based crosslinking agents are preferred from the perspective of selective crosslinking of hydroxyl groups and easy control of the crosslinking structure.

[0260] Examples of isocyanate-based crosslinking agents include Coronate HX and Millionate MR200 (both manufactured by Tosoh Corporation).

[0261] In the adhesive composition of the present invention, the preferred lower limit of the crosslinking agent content in the total amount of the adhesive composition and the crosslinking agent is 0.1% by mass, and the preferred upper limit is 20% by mass. By making the crosslinking agent content 0.1% by mass or more, the adhesive can be further cured, and the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. By making the crosslinking agent content 20% by mass or less, the adhesive obtained from the adhesive composition of the present invention does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength.

[0262] The adhesive composition of the present invention may further contain a tackifying resin (tackifier). By including a tackifying resin in the adhesive composition of the present invention, the adhesive strength is further improved.

[0263] Examples of tackifying resins used in the adhesive composition of the present invention include rosin-based resins such as rosin ester resins, terpene-based resins such as terpene phenol resins, and petroleum-based resins. Among these, rosin-based resins and terpene phenol resins with high polarity and excellent compatibility with the aforementioned vinyl monomer polymers and urethane polymers are preferred. These tackifying resins can be used alone or in combination of two or more.

[0264] The rosin ester resin in the adhesive composition of the present invention refers to a resin obtained by esterifying a rosin resin, disproportionated rosin resin, hydrogenated rosin resin, or a dimer of resin acids such as rosin acid (polymerized rosin resin) with an alcohol as the main component. A portion of the hydroxyl groups of the alcohol used in the esterification is not used for esterification but is included in the resin, thereby adjusting the hydroxyl value to the aforementioned range. Examples of alcohols include ethylene glycol, glycerol, and pentaerythritol, among other polyols.

[0265] It should be noted that the resin obtained by esterifying rosin resin is rosin ester resin, the resin obtained by esterifying disproportionated rosin resin is disproportionated rosin ester resin, the resin obtained by esterifying hydrogenated rosin resin is hydrogenated rosin ester resin, and the resin obtained by esterifying polymerized rosin resin is polymerized rosin ester resin.

[0266] The terpene phenolic resin in the adhesive composition of the present invention is a resin obtained by polymerizing terpenes in the presence of phenol.

[0267] In the adhesive composition of the present invention, the preferred lower limit of the content of the tackifying resin in the adhesive composition is 1% by mass, and the preferred upper limit is 60% by mass. By making the content of the tackifying resin 1% by mass or more, the adhesive obtained from the adhesive composition of the present invention can exhibit higher adhesive strength. By making the content of the tackifying resin 60% by mass or less, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention does not become excessively high, and the reprocessability of the adhesive obtained from the adhesive composition of the present invention is further improved. The more preferred lower limit of the content of the tackifying resin is 3% by mass, the more preferred upper limit is 50% by mass, the more preferably lower limit is 5% by mass, and the more preferably upper limit is 40% by mass.

[0268] The adhesive composition of the present invention may further contain additives such as silane coupling agents, plasticizers, softeners, fillers, pigments, and dyes as needed, without impairing the effects of the present invention.

[0269] An adhesive containing the crosslinked product of the above-mentioned vinyl monomer polymer and the above-mentioned urethane polymer in the adhesive composition of the present invention is also one of the present inventions.

[0270] By including the crosslinked product of the urethane polymer and the vinyl monomer polymer in the adhesive composition described above, the adhesive of the present invention exhibits excellent reprocessability due to the urethane polymer structure of the crosslinked product. Furthermore, the adhesive of the present invention possesses high adhesive strength due to the vinyl monomer polymer structure of the crosslinked product. Additionally, since the crosslinked product is formed by crosslinking the vinyl monomer polymer structure with the urethane polymer structure, the adhesive becomes harder, thus improving reprocessability. In other words, by including the crosslinked product, the adhesive of the present invention achieves both high adhesive strength and excellent reprocessability.

[0271] In the crosslinked products of the vinyl monomer polymer and the urethane polymer in the above adhesive composition, the vinyl monomer polymer and the urethane polymer can be crosslinked by a crosslinking agent or by a polymerization initiator. From the viewpoint of achieving better adhesion to the adhered objects, it is preferable that the vinyl monomer polymer and the urethane polymer are crosslinked by a crosslinking agent.

[0272] There are no particular limitations on the method for manufacturing the above-mentioned adhesive, and it can be manufactured by conventionally known methods. Specifically, for example, it can be manufactured by adding a crosslinking agent to an adhesive composition obtained by adding a urethane polymer, a vinyl monomer polymer or the above-mentioned compound (C1) and a tackifying resin as needed to a solvent, and then stirring thoroughly.

[0273] In addition, when the above-mentioned compound (C1) is (a) above, the adhesive can also be obtained by polymerization using the following method: mixing the above-mentioned monomer mixture, the above-mentioned photopolymerization initiator and the above-mentioned urethane polymer, applying it to a release PET film and a substrate using an applicator, sealing the upper surface after coating with a release PET film, or preventing the coated surface from contacting air under a nitrogen atmosphere, and then subjecting the substrate to UV irradiation.

[0274] Invention Effects

[0275] According to the present invention, an adhesive tape that combines high adhesion and excellent reprocessability can be provided. Furthermore, according to the present invention, an adhesive composition that simultaneously exhibits high adhesion and excellent reprocessability can be provided. Moreover, according to the present invention, an adhesive obtained from this adhesive composition can be provided. Detailed Implementation

[0276] The present invention will be described in more detail below with examples, but the present invention is not limited to these examples.

[0277] (Manufacturing of urethane polymers)

[0278] (Manufacturing of polycarbonate-based polyurethane U1)

[0279] 100 parts by mass of polycarbonate diol (Kuraray Polyol C-1090), as a polyol compound, and 0.01 parts by mass of dibutyltin dilaurate were added to a 500 mL separable flask. The mixture was stirred at 100 °C under vacuum (below 20 mmHg) for 30 minutes. Then, under normal pressure, 19 parts by mass of diphenylmethane diisocyanate (Pure MDI), as a polyisocyanate compound, were added, and the mixture was stirred at 80 °C for 3 hours to allow the reaction to proceed, yielding polycarbonate-based polyurethane U1. The weight-average molecular weight of the obtained polycarbonate-based polyurethane U1 was 17,000.

[0280] (Manufacturing of polycarbonate-based polyurethane U2)

[0281] Except that the amount of diphenylmethane diisocyanate (manufactured by Nichisho Corporation, "Pure MDI") was 23.5 parts by weight, polycarbonate polyurethane U1 was obtained by operating in the same manner. The weight-average molecular weight of the obtained polycarbonate polyurethane U2 was 70,000.

[0282] (Manufacturing of polyester-based polyurethane U3)

[0283] Except for using 100 parts by mass of polyester diol (manufactured by Ube Industries, Ltd., "ETERNACOLL 3010") as the polyol compound, polyester polyurethane U3 was obtained by operating in the same manner as polycarbonate polyurethane U1. The weight-average molecular weight of the obtained polyester polyurethane U3 was 17,000.

[0284] (Manufacturing of polyether-based polyurethane U4)

[0285] Except for using 100 parts by mass of polyether diol (manufactured by Hodogaya Chemical Co., Ltd., "PTC-L3500") as the polyol compound, polyether polyurethane U4 was obtained by operating in the same manner as polycarbonate polyurethane U1. The weight-average molecular weight of the obtained polyether polyurethane U4 was 17,000.

[0286] (Examples 1-1 to 1-13, 1-18 to 1-25, 2-1 to 2-6, 2-9 to 2-15, Comparative Examples 1 to 2, 14 to 17)

[0287] (Manufacturing of adhesives and adhesive tapes)

[0288] The monomers constituting acrylic copolymers A-E and H-M as shown in Table 1, and the urethane polymers and polymerization initiators as shown in Tables 2-5 were mixed to prepare an adhesive composition. After adding the crosslinking agents shown in Tables 2-5 to the obtained adhesive composition, the adhesive composition was applied to the release surface of a release PET film using an applicator. The release surfaces of the PET film (manufactured by NIPPA, "1-E", 50 μm thick) were overlapped and sealed in an opposing manner. An intermittent UV LED curing device (manufactured by AITEC, "M UVBA") was used to achieve a total irradiation dose of 900 mJ / cm². 2 The resulting coating was simultaneously irradiated with a wavelength of 365 nm and an illuminance of 20 mW / cm². 2 Ultraviolet light and wavelength 405nm, illuminance 40mW / cm 2 The adhesive composition is cured by exposing it to ultraviolet light for 15 seconds. As a result, an adhesive containing a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure is formed, and an adhesive layer containing the adhesive of the thickness shown in Tables 2-5 is formed. The resulting adhesive layer is used as an adhesive tape.

[0289] (Examples 1-14 to 1-15, 2-7 to 2-8, Comparative Examples 3 to 13, 18)

[0290] (Preparation of acrylic copolymers A, F, G, H, I, N)

[0291] Ethyl acetate, used as a polymerization solvent, was added to the reaction vessel for nitrogen replacement. The vessel was then heated while nitrogen was flowing in, initiating reflux. Next, a polymerization initiator solution obtained by diluting 0.1 parts by mass of azobisisobutyronitrile (AIBN) as a polymerization initiator 10 times with ethyl acetate was added to the reaction vessel, and the monomer mixture shown in Table 1 was added dropwise over 2 hours. After the addition was complete, another polymerization initiator solution obtained by diluting 0.1 parts by mass of azobisisobutyronitrile (AIBN) as a polymerization initiator 10 times with ethyl acetate was added to the reaction vessel, and the polymerization reaction was carried out for 4 hours, yielding a solution containing acrylic copolymers A, F, G, H, I, and N.

[0292] (Manufacturing of adhesives and adhesive tapes)

[0293] The urethane polymers shown in Tables 2-5 were added to the obtained solution containing acrylic copolymers A, F, G, H, I, and N to obtain a solution containing an adhesive composition. Further, the crosslinking agents shown in Tables 2-5 were added to the solution containing the adhesive composition, and the mixture was stirred thoroughly to prepare a solution containing an adhesive having a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure. The obtained adhesive solution was applied to a 50 μm thick release PET film to achieve a dried thickness of 100 μm, and then dried at 110°C for 5 minutes to form an adhesive layer. Further, the release-treated surface of a 38 μm thick release PET film was overlapped onto the formed adhesive layer in an opposing manner to obtain an adhesive tape with an adhesive layer.

[0294] (Examples 1-16 to 1-17)

[0295] (Manufacturing of adhesives and adhesive tapes)

[0296] Peel off one side of the release PET film, which has the same composition and thickness as in Example 2, to expose it. Lay the exposed adhesive layer onto one side of the substrate shown in Table 3. Further, perform the same operation on the other side of the substrate shown in Table 3, laminating the same adhesive layer, thereby obtaining a double-sided adhesive tape having a substrate and adhesive layers on both sides of the substrate.

[0297] (Gel fraction of the adhesive layer)

[0298] The adhesive tapes obtained in the examples and comparative examples were cut into planar rectangular shapes with a width of 30 mm and a length of 30 mm. Test pieces were then prepared by peeling off the release PET film. The test pieces were immersed in tetrahydrofuran (THF) at 23°C for 24 hours, filtered through a metal mesh, and dried at 110°C for 1 hour. The mass of the dried test pieces was measured, and the gel fraction of the adhesive layer was calculated using the following formula (I). The results are shown in Tables 2-5.

[0299] Gel fraction (mass%) = 100 × (W2 - W0) / (W1 - W0) (I)

[0300] (W0: quality of the substrate, W1: quality of the test piece before impregnation, W2: quality of the test piece after impregnation and drying)

[0301] (Young's modulus of the adhesive layer at 23°C)

[0302] The adhesive layers obtained in the examples and comparative examples were punched using dumbbell No. 4. For the obtained samples, tensile tests were performed using a tensile testing machine (A&D Corporation, "STB-1225S") at a tensile speed of 200 mm / min (chuck distance 50 mm) under conditions of 23°C and 50% RH. The Young's modulus (%) of the adhesive layer at 23°C was thus determined. The results are shown in Tables 2 to 5.

[0303] (Shear storage modulus of the adhesive layer at 25°C)

[0304] The adhesive layers obtained in the Examples and Comparative Examples were laminated to a thickness of 500 μm to prepare the adhesive layer for testing, and test pieces were obtained. For the obtained test pieces, the dynamic viscoelastic spectrum was measured using a dynamic viscoelasticity measuring apparatus (IT Measurement & Control Co., Ltd., "DVA-200") under nitrogen atmosphere, shear direction, frequency of 1 Hz, heating rate of 10 °C / min, and temperature range of -50 °C to 150 °C, thereby obtaining the shear storage modulus (MPa) at 25 °C. The results are shown in Tables 2-5.

[0305] (The peak temperature and half-width of the loss tangent (tanδ) in the temperature range above -10°C and below 30°C when measured at a frequency of 1 Hz for the adhesive layer)

[0306] Based on the above determination of "(shear storage modulus of the adhesive layer at 25°C)," the peak temperature (°C) and half-width of the loss tangent (tanδ) peak in the temperature region above -10°C and below 30°C were obtained from the resulting loss tangent (tanδ) spectrum. It should be noted that for Comparative Examples 3 to 13, where the peak temperature (°C) of the loss tangent is not above -10°C and below 30°C, the half-width of the loss tangent (tanδ) peak was not derived. The results are shown in Tables 2 to 5.

[0307] (The 180° peel force of the adhesive tape on SUS at 23°C and a peel speed of 300 mm / min)

[0308] The adhesive tapes obtained in the examples and comparative examples were cut into planar rectangular shapes with a width of 25 mm and a length of 80 mm. The release PET film on one side (the side not being measured) of the cut adhesive tape was peeled off, and test pieces were prepared using a 50 μm thick PET film (manufactured by Toyobo Co., Ltd., "Cosmoshine A4100") as a backing. The release PET film on the other side (the side being measured) of the prepared test piece was peeled off, and the test piece was adhered to an SUS board (a SUS304 board cleaned with ethanol and then dry-rubbed) by a 2 kg rubber roller at a speed of 10 mm / min. The board was then cured at 23°C and 50% RH for 24 hours to obtain the test samples.

[0309] For the obtained test samples, according to JIS Z0237, a tensile testing machine (A&D Corporation, "RTI-1310") was used to conduct peel tests at 23°C, 50%RH, a peel speed of 300 mm / min, and a peel angle of 180°. The peel force (N / inch) of the adhesive tape against SUS at 23°C and a peel speed of 300 mm / min was obtained. The results are shown in Tables 2-5.

[0310] (Tensile stress at 23°C and elongation at break of adhesive layer at 23°C)

[0311] The adhesive tapes obtained in the examples and comparative examples were punched using a No. 4 dumbbell (manufactured by Polymer Instruments Co., Ltd.). For the obtained adhesive layer samples, a tensile test was conducted using a tensile testing machine (manufactured by A&D Corporation, "STB-1225S") at a tensile speed of 200 mm / min (chuck distance 50 mm) under conditions of 23°C and 50% RH, stretching the adhesive layer sample along its long side. The stress at which the adhesive layer fractured was then taken as the tensile fracture stress (MPa), and the ratio of the length of the long side of the adhesive layer sample at fracture to the length of the long side of the adhesive layer sample before the tensile test was taken as the elongation at break (%). The results are shown in Tables 2-5.

[0312] It should be noted that the length of the long side of the adhesive layer mentioned above refers to the distance between the chucks of the tensile testing machine that grips the sample of the adhesive layer during the tensile test. Furthermore, for Examples 1-16 and 1-17, which have a substrate, samples of the adhesive layer obtained by punching the adhesive layer before it is laminated to the substrate using a dumbbell 4 were subjected to tensile tests.

[0313] <Evaluation>

[0314] The adhesives and adhesive tapes obtained in the examples and comparative examples were evaluated using the following methods. The results are shown in Tables 2-5.

[0315] (Adhesive transparency)

[0316] The transparency of the adhesive obtained by visual inspection is evaluated according to the following criteria.

[0317] 〇: The adhesive is transparent.

[0318] △: The adhesive is slightly cloudy.

[0319] ×: The adhesive is cloudy.

[0320] (Reprocessability of adhesive tape)

[0321] (1) Reprocessability of adhesive tape at a peel angle of 30°

[0322] The obtained adhesive tape was cut into pieces 10mm wide and 80mm long. A release PET film was peeled off and attached to an SUS304 board (cleaned with ethanol and then dry-rubbed). A 2kg rubber roller was then applied at a speed of 10mm / min for one reciprocating motion to press the tape together. The tape was then left to stand for 24 hours at 23°C and 50% RH to prepare test samples. Next, another release PET film was peeled off from the adhesive tape in the test samples to expose the adhesive layer. The end of the adhesive layer was stretched at a 30° angle from the horizontal direction at a speed of 300mm / min and peeled off from the SUS board. The reprocessability of the adhesive tape was evaluated three times for each sample according to the following criteria.

[0323] 0: In all three tests, the adhesive tape was able to be peeled off cleanly without breaking.

[0324] △: The adhesive tape was able to be peeled off cleanly without breaking in 2 tests, but broke in the middle of the peeling process in 1 test.

[0325] ×: The number of tests in which the adhesive tape can be cleanly peeled off without breaking is less than 2.

[0326] It should be noted that for Comparative Examples 17-18, based on the above-mentioned measurement results of "(180° peel force of the adhesive tape against SUS at 23°C and a peel speed of 300 mm / min)," the adhesive tape did not have adhesive force, therefore the reprocessability of the adhesive tape was not evaluated.

[0327] (2) Reprocessability of adhesive tape at a peel angle of 0°

[0328] Regarding the peel angle, it will be changed from 30° from the horizontal direction to 0° from the horizontal direction. Otherwise, the reprocessability of the adhesive tape will be further evaluated using the same method and the same judgment criteria as in "(1) Reprocessability of adhesive tape at a peel angle of 30°".

[0329] Generally, for adhesive tapes without a substrate or with a sufficiently elastic substrate such as a foam substrate, stress concentrates at the peel point as the peel angle increases, making them prone to breakage. Therefore, for adhesive tapes without a substrate or with a foam substrate as the substrate, i.e., adhesive tapes other than those in Examples 1-17, if the evaluation of "(2) reprocessability of the adhesive tape at a peel angle of 0°" is "○" or "△", then even if the evaluation of "(1) reprocessability of the adhesive tape at a peel angle of 30°" is "×", it still has sufficient reprocessability. In addition, in the evaluation of "(1) reprocessability of the adhesive tape at a peel angle of 30°", the better the evaluation, the better the reprocessability of the adhesive tape.

[0330] On the other hand, generally speaking, for adhesive tapes with a resin film as the substrate, which lacks elasticity, the adhesive layer becomes less deformable as the peel angle decreases, thus increasing the peel force. Therefore, for adhesive tapes with a resin film as the substrate, i.e., the adhesive tapes of Examples 1-17, if the evaluation of "(1) reprocessability of the adhesive tape at a peel angle of 30°" is "○" or "△", then even if the evaluation of "(2) reprocessability of the adhesive tape at a peel angle of 0°" is "×", it still has sufficient reprocessability. In addition, in the evaluation of "(1) reprocessability of the adhesive tape at a peel angle of 30°", the better the evaluation, the better the reprocessability of the adhesive tape.

[0331] The monomer symbols shown in Table 1 represent the following substances.

[0332] ·BA: n-Butyl acrylate

[0333] ·2-EHA: 2-Ethylhexyl acrylate

[0334] • Aac: Acrylic acid

[0335] HEA: 2-Hydroxyethyl Acrylate

[0336] 4-HBA: 4-Hydroxybutyl acrylate

[0337] • IBOA: Isoborneol Acrylate

[0338] ·BzA: Benzyl acrylate

[0339] [Table 1]

[0340]

[0341] [Table 2]

[0342]

[0343] [Table 3]

[0344]

[0345] [Table 4]

[0346]

[0347] [Table 5]

[0348]

[0349] Industrial applicability

[0350] According to the present invention, an adhesive tape that combines high adhesion and excellent reprocessability can be provided. Furthermore, according to the present invention, an adhesive composition that simultaneously exhibits high adhesion and excellent reprocessability can be provided. Moreover, according to the present invention, an adhesive obtained from this adhesive composition can be provided.

Claims

1. An adhesive tape, characterized in that, It has an adhesive layer containing adhesive. The adhesive tape satisfies at least one of the following configurations: configuration 1 and configuration 2. First component: The adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure. In the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked using a crosslinking agent. The vinyl monomer polymer has structural units derived from a compound (C1) selected from (a), (b) or (c) below: (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms, (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms, (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms; Second component: The thickness of the adhesive layer is 50 μm or more. The tensile fracture stress of the adhesive layer at 23°C is greater than 0.50 MPa. The adhesive tape has a 180° peel force of 5.0 N / inch or more and 30.0 N / inch or less against SUS at a peel speed of 300 mm / min and a temperature of 23°C.

2. The adhesive tape according to claim 1, wherein, The adhesive layer exhibits one peak of the loss tangent tanδ in a temperature range of -10°C to 30°C when measured at a frequency of 1 Hz, and the half-width of this loss tangent peak is below 40°C. The shear storage modulus G' of the adhesive layer at 25°C is below 1.0 MPa.

3. The adhesive tape according to claim 1 or 2, wherein, In the first configuration, the thickness of the adhesive layer is 50 μm or more. The tensile fracture stress of the adhesive layer at 23°C is greater than 0.50 MPa. The adhesive tape has a 180° peel force of 5.0 N / inch or more and 30.0 N / inch or less against SUS at a peel speed of 300 mm / min and a temperature of 23°C.

4. The adhesive tape according to claim 1 or 2, wherein, In the second configuration, the adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure. In the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked using a crosslinking agent. The vinyl monomer polymer has structural units derived from a compound (C1) selected from (a), (b) or (c) below: (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms, (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms, (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

5. The adhesive tape according to claim 1, 2, 3 or 4, wherein, The nitrogen-containing (meth)acrylate comprises at least one selected from (meth)acrylates containing urethane bonds and (meth)acrylates containing imide bonds.

6. The adhesive tape according to claim 5, wherein, The nitrogen-containing (meth)acrylates include (meth)acrylates containing urethane bonds.

7. The adhesive tape according to claim 1, 2, 3, 4, 5 or 6, wherein, Of the total 100 parts by mass of the structural units derived from (meth)acrylates containing aromatic groups and the structural units derived from (meth)acrylates containing nitrogen atoms, the content of the structural units derived from (meth)acrylates containing aromatic groups is 5 parts by mass or more and 95 parts by mass or less.

8. The adhesive tape according to claim 1, 2, 3, 4, 5, 6 or 7, wherein, The vinyl monomer polymer also has structural units derived from hydroxyl-containing (meth)acrylates.

9. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein, The vinyl monomer polymer also has structural units derived from alkyl (meth)acrylates.

10. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein, The urethane polymer has at least one structural unit selected from polyether diol, polyester diol, and polycarbonate diol.

11. The adhesive tape according to claim 10, wherein, The urethane polymer has at least one structural unit selected from polyester diol and polycarbonate diol.

12. The adhesive tape according to claim 11, wherein, The urethane polymer has structural units derived from polycarbonate diol.

13. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, wherein, The urethane polymer has structural units derived from compounds containing aromatic groups.

14. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13, wherein, Of the total 100 parts by weight of the vinyl monomer polymer and the urethane polymer, the content of the urethane polymer is more than 5 parts by weight and less than 90 parts by weight.

15. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14, wherein, The adhesive also contains a tackifying resin.

16. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, wherein, The elongation at break of the adhesive layer at 23°C is more than 300%.

17. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16, wherein, The gel content of the adhesive layer is 30% by mass or more and 99% by mass or less.

18. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 or 17, wherein, The Young's modulus of the adhesive layer at 23°C is greater than 0.010 MPa and less than 10 MPa.

19. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18, having a substrate and having the adhesive layer on at least one side of the substrate.

20. The adhesive tape according to claim 19, wherein, The substrate includes a foamed substrate.

21. The adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18, wherein it does not have a substrate.

22. An adhesive composition, characterized in that, It contains vinyl monomer polymers and urethane polymers. The vinyl monomer polymer has structural units derived from a compound (C1) selected from (a), (b) or (c) below: (a) (meth)acrylates containing aromatic groups and (meth)acrylates containing nitrogen atoms, (b) Polymers having structural units derived from (meth)acrylates containing aromatic groups and structural units derived from (meth)acrylates containing nitrogen atoms, (c) Polymers having structural units derived from (meth)acrylates containing aromatic groups and polymers having structural units derived from (meth)acrylates containing nitrogen atoms.

23. The adhesive composition according to claim 22, wherein, The nitrogen-containing (meth)acrylate comprises at least one selected from (meth)acrylates containing urethane bonds and (meth)acrylates containing imide bonds.

24. The adhesive composition according to claim 23, wherein, The nitrogen-containing (meth)acrylates include (meth)acrylates containing urethane bonds.

25. The adhesive composition according to claim 22, 23 or 24, wherein, Of the total 100 parts by mass of the structural units derived from (meth)acrylates containing aromatic groups and the structural units derived from (meth)acrylates containing nitrogen atoms, the content of the structural units derived from (meth)acrylates containing aromatic groups is 5 parts by mass or more and 95 parts by mass or less.

26. The adhesive composition according to claim 22, 23, 24 or 25, wherein, The vinyl monomer polymer also has structural units derived from hydroxyl-containing (meth)acrylates.

27. The adhesive composition according to claim 22, 23, 24, 25 or 26, wherein, The vinyl monomer polymer also has structural units derived from alkyl (meth)acrylates.

28. The adhesive composition according to claim 22, 23, 24, 25, 26 or 27, wherein, The urethane polymer has at least one structural unit selected from polyether diol, polyester diol, and polycarbonate diol.

29. The adhesive composition according to claim 28, wherein, The urethane polymer has at least one structural unit selected from polyester diol and polycarbonate diol.

30. The adhesive composition according to claim 29, wherein, The urethane polymer has structural units derived from polycarbonate diol.

31. The adhesive composition according to claim 22, 23, 24, 25, 26, 27, 28, 29 or 30, wherein, The urethane polymer has structural units derived from compounds containing aromatic groups.

32. The adhesive composition according to claim 22, 23, 24, 25, 26, 27, 28, 29, 30 or 31, wherein, Of the total 100 parts by weight of the vinyl monomer polymer and the urethane polymer, the content of the urethane polymer is more than 5 parts by weight and less than 90 parts by weight.

33. The adhesive composition according to claim 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 or 32, further comprising a tackifying resin.

34. An adhesive comprising a crosslinking product of the vinyl monomer polymer and the urethane polymer in the adhesive composition of claims 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32 or 33.

35. The adhesive according to claim 34, wherein, In the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked by a crosslinking agent.

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