Adhesive sheet, laminated sheet, chemical tank, and method for manufacturing a chemical tank

Abstract

The present invention provides an adhesive sheet that has excellent adhesion to SUS, excellent heat resistance, and excellent appearance. It also provides a laminated sheet having the adhesive sheet. Furthermore, it provides a chemical tank to which the adhesive sheet or the laminated sheet is attached. In addition, it provides a method for manufacturing a chemical tank using the adhesive sheet and the laminated sheet. [Solution] An adhesive sheet having a base material and an adhesive layer (Y1) formed on one side of the base material using an adhesive composition (X1), wherein the base material is composed of at least one selected from the group consisting of nonwoven fabric, a base material having a mesh structure, and a foam having an open-cell structure, the adhesive layer (Y1) has a gel fraction of 10% by mass or more, and the adhesive sheet has a 180° peel force of 50 N / 25 mm or more on the adhesive layer (Y1) side against SUS at 23°C.

Description

Technical Field

[0001] The present invention relates to an adhesive sheet. The present invention also relates to a laminated sheet having the adhesive sheet. Furthermore, the present invention relates to a chemical solution tank to which the adhesive sheet or the laminated sheet is attached. In addition, the present invention relates to a method for manufacturing a chemical solution tank using the adhesive sheet and the laminated sheet.

Background Art

[0002] Conventionally, when fixing various parts, adhesive sheets are widely used. Specifically, for example, an adhesive sheet is used to adhere a cover panel for protecting the surface of a portable electronic device to a touch panel module or a display panel module, or to adhere a touch panel module and a display panel module. For an adhesive sheet used for fixing such parts, in addition to high adhesiveness, functions such as heat resistance, thermal conductivity, and impact resistance are required according to the environment of the site where it is used (for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, due to excellent heat resistance, chemical resistance, low dielectric properties, and water repellency, the demand for fluororesins has been increasing in various fields. For example, polytetrafluoroethylene (PTFE) is used in a wide range of fields such as wire coating materials and building materials due to its high mechanical strength and excellent processability.

[0005] In the semiconductor and chemical industries, many chemical solutions such as acids and alkalis are used, and lined tanks with fluororesin bonded to the tank body are widely used for corrosion prevention when storing or disposing of these chemical solutions. Conventionally, when bonding fluororesin to a tank body, adhesives such as chloroprene rubber or epoxy resin were applied to both the fluororesin and the tank body, and then the two were bonded by heat and pressure. However, joining materials using this method involves applying adhesive multiple times and allowing it to dry, which takes a long time to complete. Therefore, there is a demand for joining materials that can be joined using adhesive sheets without any pretreatment.

[0006] On the other hand, when bonding fluororesin to a can body using an adhesive sheet, the adhesive sheet needs to have high adhesive strength to the stainless steel (SUS) that makes up the can body. In order for the adhesive sheet to exhibit high adhesive strength to SUS, it is necessary to make the adhesive layer that makes up the adhesive sheet thicker than a certain amount. However, there was a problem that the appearance of the adhesive sheet deteriorated when the adhesive layer was made thicker than a certain amount. Furthermore, when bonding the fluororesin to the tank body using an adhesive sheet, heat treatment is performed to soften the fluororesin, and high-temperature chemicals may be used when the tank is in use. Therefore, heat resistance is required for the adhesive sheet used to bond the fluororesin to the tank body.

[0007] The present invention provides an adhesive sheet that has excellent adhesion to SUS, excellent heat resistance, and excellent appearance. The present invention also provides a laminated sheet having the adhesive sheet. Furthermore, the present invention provides a chemical tank to which the adhesive sheet or the laminated sheet is attached. In addition, the present invention provides a method for manufacturing a chemical tank using the adhesive sheet and the laminated sheet. [Means for solving the problem]

[0008] Disclosure 1 is an adhesive sheet having a substrate and an adhesive layer (Y1) formed on one side of the substrate using an adhesive composition (X1), wherein the substrate is composed of at least one selected from the group consisting of nonwoven fabric, a substrate having a mesh structure, and a foam having an open-cell structure, the adhesive layer (Y1) has a gel fraction of 10% by mass or more, and the adhesive sheet is an adhesive sheet having a 180° peel force of 50 N / 25 mm or more on the adhesive layer (Y1) side to SUS at 23°C. Disclosure 2 is an adhesive sheet according to Disclosure 1, wherein the thickness of the adhesive layer (Y1) is 200 μm or more. Disclosure 3 is an adhesive sheet according to Disclosure 1 or 2, wherein the 180° peel force to the PTFE on the adhesive layer (Y1) side is less than 5.0 N / 25 mm. Disclosure 4 is an adhesive sheet according to Disclosure 1, 2, or 3, wherein the adhesive composition (X1) contains a base polymer (P1), and the base polymer (P1) comprises at least one selected from the group consisting of (meth)acrylic copolymers, styrene elastomers, and synthetic rubbers. Disclosure 5 is an adhesive sheet according to Disclosure 1, 2, 3, or 4, wherein the adhesive composition (X1) contains a tackifying resin (T1). Disclosure 6 is an adhesive sheet according to Disclosure 5, wherein the tackifying resin (T1) comprises at least one tackifying resin selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins. Disclosure 7 is an adhesive sheet according to Disclosure 5 or 6, wherein the content of the tackifying resin (T1) is 10 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the base polymer (P1). Disclosure 8 is an adhesive sheet according to Disclosure 1, 2, 3, 4, 5, 6, or 7, in which the adhesive composition (X1) contains a silane coupling agent. Disclosure 9 is an adhesive sheet of Disclosure 8, comprising a silane coupling agent having at least one functional group selected from the group consisting of epoxy group, amino group, vinyl group, acrylic group, methacrylic group, isocyanate group, isocyanurate group, styryl group, ureido group, acid anhydride group, and mercapto group. Disclosure 10 is an adhesive sheet according to Disclosure 8 or 9, wherein the content of the silane coupling agent is 0.1 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of the base polymer (P1). Disclosure 11 is an adhesive sheet of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the thickness of the substrate is 50 μm or more and 1000 μm or less. Disclosure 12 further comprises an adhesive sheet of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, having an adhesive layer (Y2) made of an adhesive composition (X2) on the other side of the substrate. Disclosure 13 is an adhesive sheet according to Disclosure 12, wherein the thickness of the adhesive layer (Y2) is 200 μm or more. Disclosure 14 is an adhesive sheet according to Disclosure 12 or 13, wherein the 180° peel force to the PTFE on the adhesive layer (Y2) side is less than 5.0 N / 25 mm. Disclosure 15 is an adhesive sheet according to Disclosure 12, 13, or 14, wherein the adhesive composition (X2) contains a base polymer (P2), and the base polymer (P2) comprises at least one selected from the group consisting of (meth)acrylic copolymers, styrene elastomers, and synthetic rubbers. Disclosure 16 is an adhesive sheet of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15, wherein the loss tangent (tanδ), measured by a dynamic viscoelasticity measuring device under the conditions of shear mode, heating rate of 5°C / min, and frequency of 10 Hz, has a peak in the temperature range of 10°C or higher. Disclosure 17 is an adhesive sheet of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16 used for lining a can body in a chemical tank. Disclosure 18 is a laminated sheet having a sheet containing fluororesin on a surface different from the surface of the adhesive layer (Y2) in contact with the substrate, as described in Disclosures 12, 13, 14, or 15. Disclosure 19 is a laminated sheet of Disclosure 18 in which the sheet containing the fluororesin has at least one surface treatment layer selected from the group consisting of a sodium etching layer, a glass backing layer, and an atmospheric pressure plasma treatment layer on one of its surfaces. Disclosure 20 is a laminated sheet of Disclosure 18 or 19 used to protect an adherend. Disclosure 21 is a laminated sheet of Disclosure 20 used to protect an adherend from a chemical solution. Disclosure 22 is a chemical tank in which an adhesive sheet of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 or 17, or a laminated sheet of Disclosure 18, 19, 20 or 21 is attached to the inner surface of a can body. Disclosure 23 is a method for manufacturing a chemical tank, which includes the step of attaching a laminated sheet of Disclosure 18, 19, 20, or 21 to the inner surface of the tank body of the chemical tank. Disclosure 24 is a method for manufacturing a chemical tank, comprising the steps of: manufacturing a laminated sheet using the adhesive sheet of Disclosure 12, 13, 14 or 15, and pressing a sheet containing fluororesin onto the adhesive layer (Y2); and attaching the adhesive layer (Y1) of the laminated sheet to the inner surface of the tank body of the chemical tank. The present invention will be described in detail below.

[0009] The inventors investigated the development of an adhesive sheet having a substrate and an adhesive layer (Y1) on one side of the substrate, using a specific type of substrate, setting the gel fraction of the adhesive layer (Y1) to a specific value or higher, and setting the 180° peel strength of the adhesive layer (Y1) to SUS at 23°C to a specific value or higher. As a result, they found that an adhesive sheet with excellent adhesion to SUS, excellent heat resistance, and excellent appearance could be obtained, thus completing the present invention.

[0010] The adhesive sheet of the present invention is an adhesive sheet having a base material and an adhesive layer (Y1) formed on one surface of the base material using an adhesive composition (X1). In the present specification, the above "adhesion" means not only a permanent adhesion phenomenon but also an adhesion phenomenon as "adhesion" which is a temporary adhesion phenomenon.

[0011] The adhesive sheet of the present invention has a base material. The base material is composed of at least one selected from the group consisting of a non-woven fabric, a base material having a mesh structure, and a foam having a continuous cell structure. Since the above-mentioned non-woven fabric, the base material having a mesh structure, and the foam having a continuous cell structure have air passages and can suppress the generation of air, they have high air permeability, and it becomes easy to remove the foaming generated during drying in the process of forming an adhesive layer having a large thickness. Therefore, by configuring the base material from at least one selected from the group consisting of a non-woven fabric, a base material having a mesh structure, and a foam having a continuous cell structure, it is possible to suppress the remaining of foaming on the surface of the adhesive layer, and the adhesive sheet of the present invention becomes excellent in appearance. Further, by configuring the base material from at least one selected from the group consisting of a non-woven fabric, a base material having a mesh structure, and a foam having a continuous cell structure, even when the thickness of the adhesive layer is large, it is possible to suppress the remaining of foaming on the surface of the adhesive layer. Therefore, in order to improve the adhesive strength of the adhesive layer to SUS, it becomes possible to more easily increase the thickness of the adhesive layer.

[0012] Examples of the non-woven fabric include rayon non-woven fabric, polyester non-woven fabric, aramid non-woven fabric, and the like. Examples of commercially available products among the above non-woven fabrics include G2260-1S (manufactured by Toray International Co., Ltd.), KH-3003K (manufactured by Nippon Bylene Co., Ltd.), and the like.

[0013] Examples of the base material having a mesh structure include glass cloth, carbon cloth, metal mesh, and the like. Among the commercially available glass cloths, for example, KS2770 (manufactured by Nitto Boseki Co., Ltd.), 1031NT-1270 S640 (manufactured by Arisawa Manufacturing Co., Ltd.), L73A×1045 (manufactured by Arisawa Manufacturing Co., Ltd.), etc. can be mentioned. Among the commercially available carbon cloths, for example, CF1K (manufactured by Arisawa Manufacturing Co., Ltd.), C-540 (manufactured by Hagiwara Industry Co., Ltd.), etc. can be mentioned. Among the commercially available metal meshes, for example, Naslon (manufactured by Nippon Seisen Co., Ltd.), etc. can be mentioned.

[0014] Examples of the foam having the above-mentioned continuous cell structure include continuous cell polyurethane foam, continuous cell polyethylene foam, continuous cell EPDM (ethylene propylene rubber) foam, etc. Among the commercially available continuous cell polyurethane foams, for example, Poron (manufactured by Inoac Corporation), Super Opcel (manufactured by Kyosho Co., Ltd.), Opselaer (manufactured by Kyosho Co., Ltd.), etc. can be mentioned.

[0015] It is preferable that the above-mentioned base material has a surface treatment layer. By having the surface treatment layer, the interlayer strength of the adhesive sheet of the present invention is further improved, and it has higher adhesiveness to SUS. Examples of the above-mentioned surface treatment layer include a corona treatment layer in which the surface of the base material is corona-treated, a heat cleaning layer in which the surface of the base material is heat-cleaned, a silane treatment layer in which the surface of the base material is silane-treated, etc.

[0016] The preferable lower limit of the thickness of the above-mentioned surface treatment layer is 1 nm. When the thickness of the surface treatment layer is 1 nm or more, the interlayer strength of the adhesive sheet of the present invention is further improved, and it has higher adhesiveness to SUS. The more preferable lower limit of the thickness of the surface treatment layer is 5 nm.

[0017] The preferred lower limit for the thickness of the above-mentioned substrate is 50 μm, and the preferred upper limit is 1000 μm. Having the substrate thickness within this range further improves the interlayer strength of the adhesive sheet of the present invention, resulting in higher adhesion to SUS. A more preferred lower limit for the thickness of the above-mentioned substrate is 100 μm, and a more preferred upper limit is 500 μm.

[0018] The adhesive sheet of the present invention has an adhesive layer (Y1) formed using an adhesive composition (X1). The adhesive layer (Y1) is formed using the adhesive composition (X1). A method for forming the adhesive layer (Y1) using the adhesive composition (X1) is, for example, to apply the adhesive composition (X1) to a release film or the like, and then heat-dry the adhesive composition (X1).

[0019] The lower limit of the gel fraction of the adhesive layer (Y1) is 10% by mass. A gel fraction of 10% by mass or more in the adhesive layer (Y1) increases the bulk strength of the adhesive layer (Y1) and improves its adhesion to SUS. As a result, the adhesive sheet of the present invention exhibits excellent adhesion to SUS. Furthermore, because the bulk strength of the adhesive layer (Y1) is increased, the adhesive sheet of the present invention exhibits excellent heat resistance. A preferred lower limit for the gel fraction of the adhesive layer (Y1) is 15% by mass, and a more preferred lower limit is 20% by mass. Furthermore, the upper limit of the gel fraction of the adhesive layer (Y1) is not particularly limited and may be 100% by mass. When the gel fraction of the adhesive layer (Y1) is 100% by mass or less, the flexibility of the adhesive layer (Y1) is further improved, and the adhesive strength of the adhesive layer (Y1) to SUS is further improved. As a result, the adhesive sheet of the present invention has superior adhesion to SUS. The preferred upper limit of the gel fraction of the adhesive layer (Y1) is 75% by mass, and the more preferred upper limit is 50% by mass. The gel fraction of the adhesive layer (Y1) can be measured by the following methods, etc. Specifically, a test specimen is prepared by cutting a laminate having the adhesive layer (Y1) and a substrate, or the adhesive layer (Y1) alone, into a planar rectangular shape with a width of 50 mm and a length of 100 mm. The test specimen is immersed in an organic solvent at 23°C for 24 hours, then removed from the organic solvent and dried at 110°C for 1 hour. The organic solvent can be ethyl acetate if the base polymer (P1) described later is a (meth)acrylic copolymer, or toluene if the base polymer (P1) described later is a styrene-based elastomer or synthetic rubber. The mass of the dried test specimen is measured, and the gel fraction is calculated using the following formula (1). Note that the test specimen is assumed to have no release film laminated to protect the adhesive layer (Y1). Furthermore, if the test specimen does not have a substrate, W0 is set to 0 in the calculation. Gel fraction (mass %) = 100 × (W2 - W0) / (W1 - W0) (1) (W0: Mass of the substrate, W1: Mass of the test specimen before immersion, W2: Mass of the test specimen after immersion and drying)

[0020] Methods for adjusting the gel fraction of the adhesive layer (Y1) include, for example, changing the type or constituent units of the base polymer (P1) described later (for example, changing the copolymerization ratio or monomer composition of the base polymer (P1)), or adjusting the type or content of the tackifying resin (T1) described later (for example, improving the gel fraction of the adhesive layer (Y1) by reducing the content of the tackifying resin (T1)).

[0021] The adhesive sheet of the present invention has a lower limit of 50 N / 25 mm for the 180° peel force against SUS at 23°C on the adhesive layer (Y1) side. Since the 180° peel force against SUS at 23°C on the adhesive layer (Y1) side is 50 N / 25 mm or higher, the adhesive strength of the adhesive layer (Y1) against SUS is excellent, and therefore the adhesive sheet of the present invention has excellent adhesion to SUS. A preferred lower limit for the 180° peel force against SUS at 23°C on the adhesive layer (Y1) side after heating is 75 N / 25 mm, and a more preferred lower limit is 100 N / 25 mm. Furthermore, there is no particular preferred upper limit for the 180° peel force against SUS at 23°C on the adhesive layer (Y1) side, but the practical upper limit is 500 N / 25 mm. The 180° peel force on the adhesive layer (Y1) at 23°C relative to SUS can be measured by the following method. Specifically, the obtained adhesive sheet is cut to a size of 25 mm wide x 100 mm long, and the adhesive layer (Y1) side is placed on a SUS plate (SUS304 plate that has been washed with ethanol and then wiped dry). A laminate is then created by pressing the two layers together using a 2 kg rubber roller at a speed of 300 mm / min for one back-and-forth motion. The resulting laminate is then pressed under pressure at 0.1 MPa for 10 minutes in an environment of 120°C, and a 180° peel test is performed using a tensile testing machine (e.g., ORIENTEC's "Tensilon") in accordance with JIS Z 0237, under conditions of 23°C, 50% RH, and a peeling speed of 300 mm / min. By peeling the adhesive sheet from the SUS plate, the 180° peel force of the adhesive layer (Y1) side relative to SUS at 23°C can be measured. Furthermore, if the adhesive sheet of the present invention has an adhesive layer (Y2) described later, the adhesive sheet, with the adhesive layer (Y2) side backed with a 50 μm thick polyimide (PI) film, is cut by making one back-and-forth motion at a speed of 300 mm / min using a 2 kg rubber roller. After that, a laminate is prepared and pressed using the method described above, and a 180° peel test is performed.

[0022] Methods for adjusting the 180° peel force on SUS at 23°C on the adhesive layer (Y1) side include, for example, changing the type or constituent units of the base polymer (P1) described later (for example, changing the copolymerization ratio or monomer composition of the base polymer (P1)), adjusting the type or content of the tackifying resin (T1) described later, changing the thickness of the adhesive layer (Y1), or changing the substrate.

[0023] The adhesive layer (Y1) is formed using the adhesive composition (X1). The above adhesive composition (X1) preferably contains a base polymer (P1). Examples of the base polymer (P1) include (meth)acrylic copolymers, styrene elastomers, silicone resins, urethane resins, and synthetic rubbers. In particular, the base polymer (P1) preferably contains at least one selected from the group consisting of (meth)acrylic copolymers, styrene elastomers, and synthetic rubbers, from the viewpoint of easily exhibiting strong adhesion and being able to easily adjust the monomer composition. In this specification, the term "base polymer" refers to a polymer that accounts for 50% by mass or more of the polymers with a weight-average molecular weight of 50,000 or more contained in the adhesive composition. Furthermore, in this specification, "(meth)acrylic" means acrylic or methacrylic.

[0024] The above (meth)acrylic copolymer preferably has constituent units derived from alkyl (meth)acrylate. The above-mentioned alkyl (meth)acrylate-derived structural units preferably include structural units derived from alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus. The above-mentioned (meth)acrylic copolymer has structural units derived from alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus, which further lowers the glass transition temperature (Tg) of the above-mentioned (meth)acrylic copolymer. As a result, the flexibility of the adhesive layer (Y1) is further improved, and the adhesive sheet of the present invention has higher adhesion to SUS. In this specification, "(meth)acrylate" means acrylate or methacrylate. Furthermore, in this specification, the term "alkyl (meth)acrylate having an alkyl group at the ester terminus" means a (meth)acrylate in which an alkyl group is bonded to the oxygen atom of the ester bond.

[0025] Examples of alkyl (meth)acrylates having an alkyl group with 4 to 12 carbon atoms at the ester end include n-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, 1-methylheptyl (meth)acrylate, and lauryl (meth)acrylate. In particular, since the adhesive sheet of the present invention exhibits superior adhesion to SUS, it is preferable that the alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at the ester end includes alkyl (meth)acrylate having an alkyl group with 6 to 8 carbon atoms at the ester end. The alkyl (meth)acrylates having an alkyl group with 4 to 12 carbon atoms at the ester terminus may be used alone or in combination of two or more types.

[0026] The preferred lower limit for the content of constituent units derived from alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus in the above (meth)acrylic copolymer is 50% by mass. When the content of constituent units derived from alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus is 50% by mass or more, the glass transition temperature (Tg) of the above (meth)acrylic copolymer is further reduced, and as a result the flexibility of the adhesive layer (Y1) is further improved, so that the adhesive sheet of the present invention has higher adhesion to SUS. A more preferred lower limit for the content of constituent units derived from alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus is 90% by mass, and an even more preferred lower limit is 95% by mass. In particular, the preferred lower limit for the content of constituent units derived from alkyl (meth)acrylate having an alkyl group with 6 to 8 carbon atoms at its ester terminus in the above (meth)acrylic copolymer is 50% by mass, a more preferred lower limit is 85% by mass, and an even more preferred lower limit is 90% by mass. Furthermore, from the viewpoint of further improving the bulk cohesive force of the adhesive layer (Y1), the preferred upper limit for the content of constituent units derived from alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus is 99.5% by mass, and the more preferred upper limit is 99% by mass.

[0027] The alkyl (meth)acrylate described above may include other alkyl (meth)acrylates other than the alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus. Examples of the other alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, myristyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, ester of 5,7,7-trimethyl-2-(1,3,3-trimethylbutyl)octanol-1 and (meth)acrylic acid, ester of an alcohol with a total of 18 carbon atoms having 1 or 2 methyl groups in a linear main chain and (meth)acrylic acid, behenyl (meth)acrylate, arachidyl (meth)acrylate, and the like. The above-mentioned other alkyl (meth)acrylates may be used individually or in combination of two or more.

[0028] Preferably, the (meth)acrylic copolymer further contains structural units derived from polar functional group-containing monomers. The presence of structural units derived from polar functional group-containing monomers in the (meth)acrylic copolymer increases the bulk strength of the adhesive layer (Y1) and improves the adhesion of the adhesive layer (Y1) to SUS, resulting in the adhesive sheet of the present invention having superior adhesion to SUS. Furthermore, the increased bulk strength of the adhesive layer (Y1) results in the adhesive sheet of the present invention having excellent heat resistance.

[0029] The constituent units derived from the above polar functional group-containing monomers are constituent units derived from monomers containing functional groups that have reactivity such as crosslinking reactions, and it is preferable that the constituent units are derived from monomers containing at least one functional group selected from the group consisting of carboxyl groups, hydroxyl groups, amino groups, and epoxy groups. In particular, it is more preferable that the constituent units derived from the above polar functional group-containing monomers include one constituent unit selected from the group consisting of constituent units derived from carboxyl group-containing monomers and constituent units derived from hydroxyl group-containing monomers, as this can contribute to improving the adhesion of the adhesive sheet of the present invention to SUS. Examples of constituent units derived from the above-mentioned carboxyl group-containing monomers include constituent units derived from (meth)acrylic acid. Examples of the hydroxyl group-containing monomers mentioned above include constituent units derived from 4-hydroxybutyl (meth)acrylate and constituent units derived from 2-hydroxyethyl (meth)acrylate. Examples of constituent units derived from polar functional group-containing monomers (epoxy group-containing monomers) having an epoxy group as the polar functional group include constituent units derived from glycidyl (meth)acrylate. The constituent units derived from the above polar functional group-containing monomers may be used individually or in combination of two or more types.

[0030] In the above (meth)acrylic copolymer, the preferred lower limit for the content of constituent units derived from the carboxyl group-containing monomer is 0.01% by mass, and the preferred upper limit is 6.0% by mass. When the content of constituent units derived from the carboxyl group-containing monomer is within this range, the bulk strength of the adhesive layer (Y1) is increased, and the adhesive strength of the adhesive layer (Y1) to SUS is further improved, resulting in the adhesive sheet of the present invention having superior adhesion to SUS. Furthermore, because the bulk strength of the adhesive layer (Y1) is increased, the adhesive sheet of the present invention has excellent heat resistance. A more preferred lower limit for the content of constituent units derived from the carboxyl group-containing monomer is 0.05% by mass, and a more preferred upper limit is 3.0% by mass.

[0031] In the above (meth)acrylic copolymer, the preferred lower limit for the content of constituent units derived from the above hydroxyl group-containing monomer is 0.01% by mass, and the preferred upper limit is 5.0% by mass. When the content of constituent units derived from the above hydroxyl group-containing monomer is within this range, the bulk strength of the adhesive layer (Y1) is increased, and the adhesive strength of the adhesive layer (Y1) to SUS is further improved, resulting in the adhesive sheet of the present invention having superior adhesion to SUS. Furthermore, because the bulk strength of the adhesive layer (Y1) is increased, the adhesive sheet of the present invention has excellent heat resistance. A more preferred lower limit for the content of constituent units derived from the above hydroxyl group-containing monomer is 0.05% by mass, and a more preferred upper limit is 3.0% by mass.

[0032] In the above (meth)acrylic copolymer, the preferred lower limit for the total content of constituent units derived from the above polar functional group-containing monomer is 0.01% by mass, and the preferred upper limit is 6.0% by mass. When the total content of constituent units derived from the above polar functional group-containing monomer is within this range, the bulk strength of the adhesive layer (Y1) increases, and the adhesive strength of the adhesive layer (Y1) to SUS improves, resulting in the adhesive sheet of the present invention having superior adhesion to SUS. Furthermore, because the bulk strength of the adhesive layer (Y1) increases, the adhesive sheet of the present invention has superior heat resistance. A more preferred lower limit for the total content of constituent units derived from the above polar functional group-containing monomer is 0.1% by mass, and a more preferred upper limit is 3.0% by mass.

[0033] The above (meth)acrylic copolymer may optionally contain structural units derived from other copolymerizable monomers other than the alkyl (meth)acrylate and the polar functional group-containing monomer. Examples of other monomers mentioned above include benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and polypropylene glycol mono(meth)acrylate. In addition, other monomers that can be used include vinyl carboxylates such as vinyl acetate and various monomers commonly used in acrylic polymers such as styrene. The other monomers mentioned above may be used individually or in combination of two or more.

[0034] The preferred lower limit for the weight-average molecular weight (Mw) of the above (meth)acrylic copolymer is 50,000, and the preferred upper limit is 1,600,000. A weight-average molecular weight (Mw) of 50,000 or more increases the bulk strength of the adhesive layer (Y1) and improves the adhesion of the adhesive layer (Y1) to SUS, resulting in the adhesive sheet of the present invention having superior adhesion to SUS. Furthermore, the increased bulk strength of the adhesive layer (Y1) results in superior heat resistance for the adhesive sheet of the present invention. A weight-average molecular weight (Mw) of 1,600,000 or less further improves the flexibility of the adhesive layer (Y1), resulting in the adhesive sheet of the present invention having high adhesion to SUS. A more preferred lower limit for the weight-average molecular weight (Mw) of the above (meth)acrylic copolymer is 100,000, and a more preferred upper limit is 1,200,000.

[0035] The preferred lower limit of the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the above (meth)acrylic copolymer (molecular weight distribution (Mw / Mn)) is 1.05, and the preferred upper limit is 10.0. When the molecular weight distribution (Mw / Mn) of the above (meth)acrylic copolymer is 1.05 or higher, the flexibility of the adhesive layer (Y1) is further improved, and the adhesive sheet of the present invention has better adhesion to SUS. When the molecular weight distribution (Mw / Mn) of the above (meth)acrylic copolymer is 10.0 or lower, the proportion of low molecular weight components is suppressed, the bulk strength of the adhesive layer (Y1) is increased, and the adhesive strength of the adhesive layer (Y1) to SUS is further improved, and the adhesive sheet of the present invention has better adhesion to SUS. Furthermore, since the bulk strength of the adhesive layer (Y1) is increased, the adhesive sheet of the present invention has better heat resistance. A more preferable upper limit for the molecular weight distribution (Mw / Mn) of the above (meth)acrylic copolymer is 9.0, a further preferable upper limit is 8.0, and a more preferable upper limit is 7.0.

[0036] In this specification, weight-average molecular weight (Mw) and number-average molecular weight (Mn) refer to the weight-average molecular weight and number-average molecular weight (Mn) measured in standard polystyrene equivalent as determined by gel permeation chromatography (GPC), respectively. Specifically, a (meth)acrylic copolymer is diluted 50-fold with tetrahydrofuran (THF), and the diluted solution is filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm). The resulting filtrate is supplied to a gel permeation chromatograph (Waters, "2690 Separations Module," etc.), and GPC measurement is performed under conditions of sample flow rate of 1 mL / min and column temperature of 40°C to measure the polystyrene equivalent molecular weight of the (meth)acrylic copolymer and determine the weight-average molecular weight (Mw) and number-average molecular weight (Mn). For example, a GPC KF-802.5L (Showa Denko Corporation) can be used as the column, and for example, a differential refractometer can be used as the detector. Furthermore, the molecular weight distribution (Mw / Mn) can be measured using the obtained weight-average molecular weight (Mw) and number-average molecular weight (Mn).

[0037] Methods for adjusting the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the above-mentioned (meth)acrylic copolymer to within the above range include, for example, adjusting the composition of the monomers constituting the (meth)acrylic copolymer, the polymerization method, the polymerization conditions, etc.

[0038] The preferred lower limit of the glass transition temperature (Tg) of the above (meth)acrylic copolymer is -70°C, and the preferred upper limit is -30°C. Having the glass transition temperature of the above (meth)acrylic copolymer within this range results in the adhesive sheet of the present invention having superior adhesion to SUS. A more preferred lower limit of the glass transition temperature (Tg) of the above (meth)acrylic copolymer is -60°C, and a more preferred upper limit is -40°C. In this specification, the glass transition temperature is the value obtained in the first run when measured using a differential scanning calorimeter (for example, Hitachi High-Tech Science Corporation's "SII Exstar 6000 / DSC 6220") under a nitrogen atmosphere and a heating rate of 10°C / min.

[0039] As polymerization methods for synthesizing the above-mentioned (meth)acrylic copolymer, conventionally known methods can be used in which monomers from which the above-mentioned constituent units are derived are subjected to a radical reaction in the presence of a polymerization initiator. Examples include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, and bulk polymerization. Among these, solution polymerization is preferred because it is easy to synthesize.

[0040] When solution polymerization is used as the polymerization method described above, examples of reaction solvents include ethyl acetate, toluene, methyl ethyl ketone, methyl sulfoxide, ethanol, acetone, and diethyl ether. The above reaction solvents may be used individually or in combination of two or more types.

[0041] Examples of polymerization initiators include organic peroxides and azo compounds. Examples of the above-mentioned organic peroxides include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, and t-butylperoxylaurate. Examples of the above-mentioned azo compounds include azobisisobutyronitrile and azobiscyclohexanecarbonitride. The polymerization initiators described above may be used alone or in combination of two or more.

[0042] The styrene-based elastomer is preferably a block copolymer having a block derived from the styrene-based monomer and a block derived from a conjugated diene monomer, possessing rubber elasticity at room temperature, and having a hard segment portion and a soft segment portion. The block derived from the styrene-based monomer is the hard segment portion, and the block derived from the conjugated diene monomer is the soft segment portion.

[0043] Examples of the styrene monomers mentioned above include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, vinylethylbenzene, divinylbenzene, trivinylbenzene, divinylnaphthalene, t-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, N,N-dimethylaminoethylstyrene, N,N-dimethylaminomethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-t-butylstyrene, 3-t-butylstyrene, 4-t-butylstyrene, vinylxylene, vinylnaphthalene, vinylpyridine, diphenylethylene, and tertiary amino group-containing diphenylethylene. Among these, styrene is preferred because it is readily available industrially. Examples of the tertiary amino group-containing diphenylethylene mentioned above include 1-(4-N,N-dimethylaminophenyl)-1-phenylethylene. The above-mentioned styrene monomers may be used individually or in combination of two or more types.

[0044] Examples of the above-mentioned conjugated diene monomers include isoprene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 1,3-heptadiene, 2-phenyl-1,3-butadiene, 3-methyl-1,3-pentadiene, and 2-chloro-1,3-butadiene. Among these, 1,3-butadiene and isoprene are preferred due to their high polymerization reactivity and ease of industrial availability. The above-mentioned conjugated diene monomers may be used individually or in combination of two or more types.

[0045] Examples of the styrene-based elastomers mentioned above include styrene-isoprene-styrene (SIS) block copolymer, styrene-butadiene-styrene (SBS) block copolymer, styrene-ethylene-butylene-styrene copolymer (SEBS), and styrene-ethylene-propylene-styrene copolymer (SEPS). Among these, SIS block copolymer and SBS block copolymer are preferred, and SIS block copolymer is more preferred, because the resulting adhesive sheet tends to exhibit high adhesive strength and is less likely to peel off the adherend even when immersed in an alkaline chemical solution. The above-mentioned styrene-based elastomers may be used individually or in combination of two or more types.

[0046] The styrene-based elastomer preferably includes a triblock copolymer of a block derived from the styrene-based monomer and a block derived from the conjugated diene monomer, and more preferably includes a diblock copolymer of a block derived from the styrene-based monomer and a block derived from the conjugated diene monomer, in addition to the triblock copolymer. The preferred lower limit for the content of the diblock copolymer in the styrene-based elastomer (hereinafter sometimes referred to as the "diblock ratio") is 50% by mass. When the diblock ratio is 50% by mass or more, the flexibility of the adhesive layer (Y1) is further improved, and the adhesive sheet of the present invention has better adhesion to SUS. A more preferred lower limit for the diblock ratio is 70% by mass. Furthermore, from the viewpoint of further improving the cohesive force of the adhesive layer (Y1), the preferred upper limit of the jiblock ratio is 90% by mass. The above diblock ratio can be calculated from the peak area ratio of each copolymer measured by gel permeation chromatography (GPC).

[0047] A preferred upper limit for the content of blocks derived from the styrene monomer in the above-mentioned styrene-based elastomer (hereinafter sometimes referred to as "styrene content") is 20% by mass. A styrene content of 20% by mass or less further improves the flexibility of the adhesive layer (Y1), resulting in the adhesive sheet of the present invention having superior adhesion to SUS. A more preferred upper limit for the styrene content is 16% by mass. Furthermore, from the viewpoint of further improving the cohesive force of the adhesive layer (Y1), the preferred lower limit of the styrene content is 8% by mass. The above styrene content is, 1 It can be calculated from the peak area ratio of each block measured by 1H-NMR.

[0048] The preferred lower limit for the weight-average molecular weight of the above styrene-based elastomer is 50,000, and the preferred upper limit is 600,000. A weight-average molecular weight of 50,000 or more for the above styrene-based elastomer increases the bulk strength of the adhesive layer (Y1) and improves the adhesive strength of the adhesive layer (Y1) to SUS, resulting in the adhesive sheet of the present invention having superior adhesion to SUS. Furthermore, the increased bulk strength of the adhesive layer (Y1) results in the adhesive sheet of the present invention having superior heat resistance. A weight-average molecular weight of 600,000 or less for the above styrene-based elastomer further improves the compatibility between the styrene-based elastomer and other components. A more preferred lower limit for the weight-average molecular weight of the above styrene-based elastomer is 100,000, and a more preferred upper limit is 500,000.

[0049] Examples of the synthetic rubbers mentioned above include chloroprene rubber, nitrile rubber, acrylic rubber, isoprene rubber, ethylene propylene rubber, ethylene vinyl acetate rubber, urethane rubber, nitrile butadiene rubber, fluororubber, butadiene rubber, styrene butadiene rubber, and butyl rubber. In particular, from the viewpoint of heat resistance, chemical resistance, and weather resistance, it is preferable that the synthetic rubbers mentioned above include chloroprene rubber, which has chlorine in the carbon-carbon double bond in its molecule. Examples of commercially available chloroprene rubber include 575F (manufactured by Cemedyne Co., Ltd.) and G17 (manufactured by Konishi Co., Ltd.). Examples of commercially available nitrile rubbers include 501F (manufactured by Cemedyne Co., Ltd.).

[0050] The preferred lower limit and preferred upper limit of the content of the base polymer (P1) in the adhesive composition (X1) are 30% by mass and 99.5% by mass, respectively. By having the base polymer (P1) content within this range, the adhesive strength of the adhesive layer (Y1) to SUS is further improved, resulting in the adhesive sheet of the present invention having higher adhesion to SUS. A more preferred lower limit for the base polymer (P1) content is 40% by mass, a more preferred upper limit is 99% by mass, an even more preferred lower limit is 50% by mass, and an even more preferred upper limit is 95% by mass.

[0051] The adhesive composition (X1) preferably contains a tackifying resin (T1). By including the tackifying resin (T1) in the adhesive composition (X1), the adhesive strength of the adhesive layer (Y1) to SUS is further improved, and the adhesive sheet of the present invention has superior adhesion to SUS.

[0052] The tackifying resin (T1) preferably contains at least one tackifying resin selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins. By including at least one tackifying resin selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins in the tackifying resin (T1), the adhesive strength of the adhesive layer (Y1) to SUS is further improved, and the adhesive sheet of the present invention has better adhesion to SUS. In particular, since the adhesive strength to SUS can be further improved, it is more preferable that the tackifying resin (T1) contains at least one tackifying resin selected from the group consisting of rosin ester resins and terpene resins.

[0053] The preferred lower limit of the softening temperature of the tackifying resin (T1) is 50°C, and the preferred upper limit is 200°C. A softening temperature of 50°C or higher for the tackifying resin (T1) further improves the heat resistance of the adhesive layer (Y1). A softening temperature of 200°C or lower for the tackifying resin (T1) further improves the wettability and flexibility of the interface of the adhesive layer (Y1), and further improves the adhesive strength to SUS, resulting in the adhesive sheet of the present invention having superior adhesion to SUS. A more preferred lower limit of the softening temperature of the tackifying resin (T1) is 70°C, and a more preferred upper limit is 150°C. Note that the softening temperature refers to the softening temperature measured according to JIS K 2207 (ring-ball method).

[0054] The preferred lower limit of the hydroxyl value of the tackifying resin (T1) is 0 mgKOH / g, and the preferred upper limit is 200 mgKOH / g. Having the hydroxyl value of the tackifying resin (T1) within this range improves the wettability of the interface of the adhesive layer (Y1) and further improves the adhesive strength to SUS, resulting in the adhesive sheet of the present invention having superior adhesion to SUS. A more preferred lower limit of the hydroxyl value of the tackifying resin (T1) is 30 mgKOH / g, and a more preferred upper limit is 130 mgKOH / g. The above hydroxyl value can be measured according to JIS K 1557 (phthalic anhydride method).

[0055] The rosin ester resins mentioned above are resins obtained by esterifying rosin resins mainly composed of abietic acid, disproportionated rosin resins, hydrogenated rosin resins, or dimers of resin acids such as abietic acid (polymerized rosin resins) with alcohol. Some of the hydroxyl groups of the alcohol used in esterification are not used in the esterification process and are instead contained within the resin, thereby adjusting the hydroxyl value to the range described above. Examples of such alcohols include polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol. Examples of commercially available rosin ester resins include Pine Crystal KE-359 (manufactured by Arakawa Chemical Industries, Ltd., hydroxyl value: 40 mg KOH / g, softening temperature: 100°C).

[0056] The above-mentioned terpene resin is a resin that has structural units derived from monoterpene compounds and does not have structural units derived from aromatic compounds. Examples of commercially available terpene resins include YS Resin PX1250 (manufactured by Yasuhara Chemical Co., Ltd., hydroxyl value: 0 mg KOH / g, softening temperature: 125°C).

[0057] The above-mentioned terpene phenol resin is a resin having structural units derived from monoterpene compounds and structural units derived from phenol compounds. In this specification, the term "phenol compound" in the terpene phenol resin refers to a compound that contains an aromatic ring structure having only one phenolic hydroxyl group and does not contain an aromatic ring structure having two or more phenolic hydroxyl groups. Examples of commercially available terpene phenol resins include YS Polystar G150 (manufactured by Yasuhara Chemical Co., Ltd., hydroxyl value: 120 mg KOH / g, softening temperature: 150°C).

[0058] Examples of commercially available petroleum-based resins include Alcon P-140 (manufactured by Arakawa Chemical Industries, Ltd., hydroxyl value: 0 mg KOH / g, softening temperature: 140°C).

[0059] The preferred upper limit for the content of the tackifying resin (T1) per 100 parts by mass of the base polymer (P1) is 150 parts by mass. By having a content of 150 parts by mass or less of the tackifying resin (T1), the flexibility of the adhesive layer (Y1) is further improved, and the adhesive strength to SUS is further improved, so the adhesive sheet of the present invention has better adhesion to SUS. In addition, it becomes easier to adjust the gel fraction of the adhesive layer (Y1) to within the above range, so the adhesive sheet of the present invention has better heat resistance. The more preferred upper limit for the content of the tackifying resin (T1) is 100 parts by mass, an even more preferred upper limit is 70 parts by mass, and an even more preferred upper limit is 40 parts by mass. The lower limit of the content of the tackifying resin (T1) is not particularly limited and may be 0 parts by mass (i.e., the adhesive layer (Y1) does not need to contain the tackifying resin (T1)). However, from the viewpoint of further improving the adhesive strength of the adhesive layer (Y1) to SUS, a preferred lower limit is 10 parts by mass, and a more preferred lower limit is 20 parts by mass.

[0060] The adhesive composition (X1) preferably contains a silane coupling agent. By containing a silane coupling agent in the adhesive composition (X1), the adhesive strength of the adhesive layer (Y1) to SUS is further improved, and the adhesive sheet of the present invention has better adhesion to SUS.

[0061] Examples of the silane coupling agents mentioned above include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane. In particular, from the viewpoint of further improving the adhesive strength of the adhesive layer (Y1) to SUS and ensuring that the adhesive sheet of the present invention has superior adhesion to SUS, it is preferable that the silane coupling agent includes a silane coupling agent having at least one functional group selected from the group consisting of epoxy group, amino group, vinyl group, acrylic group, methacrylic group, isocyanate group, isocyanurate group, styryl group, ureido group, acid anhydride group, and mercapto group. The silane coupling agents described above may be used individually or in combination of two or more.

[0062] The preferred lower limit for the content of the silane coupling agent per 100 parts by mass of the base polymer (P1) is 0.1 parts by mass, and the preferred upper limit is 5.0 parts by mass. A content of 0.1 parts by mass or more of the silane coupling agent improves the adhesion of the adhesive layer (Y1) to SUS, resulting in superior adhesion of the adhesive sheet of the present invention to SUS and improved adhesion to the substrate. A content of 5.0 parts by mass or less of the silane coupling agent makes it easier to adjust the gel fraction of the adhesive layer (Y1) to the above-mentioned range, resulting in superior heat resistance of the adhesive sheet of the present invention. Furthermore, it is possible to suppress the bleed-out of the silane coupling agent. A more preferred lower limit for the content of the silane coupling agent is 0.5 parts by mass, and a more preferred upper limit is 2.0 parts by mass.

[0063] The adhesive composition (X1) preferably contains a crosslinking agent. In particular, if the base polymer (P1) contains the (meth)acrylic copolymer, the adhesive composition (X1) preferably contains a crosslinking agent. By containing the crosslinking agent in the adhesive composition (X1), the (meth)acrylic copolymer can form a structure that is crosslinked by chemical crosslinking, thereby improving the bulk cohesive strength of the adhesive layer (Y1) and increasing the gel fraction of the adhesive layer (Y1), as described later. As a result, the adhesive sheet of the present invention has superior adhesion to SUS and superior heat resistance. Furthermore, from the viewpoint of storage stability, etc., the crosslinking agent may be added to the adhesive composition (X1) immediately before forming the adhesive layer (Y1).

[0064] Examples of the crosslinking agents include isocyanate-based crosslinking agents, aziridine-based crosslinking agents, epoxy-based crosslinking agents, and metal chelate-type crosslinking agents. In particular, it is preferable that the crosslinking agent includes at least one selected from the group consisting of isocyanate-based crosslinking agents and epoxy-based crosslinking agents, as this enables appropriate chemical crosslinking of the (meth)acrylic copolymer and further improves the adhesive strength of the adhesive layer (Y1).

[0065] Examples of commercially available isocyanate-based crosslinking agents include Takenate 500 (manufactured by Mitsui Chemicals, Inc.) and Desmodulo L-75 (manufactured by Covestro Corporation).

[0066] The preferred lower limit for the content of the crosslinking agent in the adhesive composition (X1) per 100 parts by mass of the (meth)acrylic copolymer is 0.01 parts by mass, and the preferred upper limit is 20 parts by mass. By having the crosslinking agent content within this range, appropriate chemical crosslinking of the (meth)acrylic copolymer becomes possible, further improving the adhesion of the adhesive layer (Y1) to SUS, thus the adhesive sheet of the present invention exhibits superior adhesion to SUS. A more preferred lower limit for the crosslinking agent content is 0.1 parts by mass, a more preferred upper limit is 10.0 parts by mass, an even more preferred lower limit is 0.5 parts by mass, and an even more preferred upper limit is 8.0 parts by mass.

[0067] The above adhesive composition (X1) may optionally contain conventionally known fine particles and additives such as inorganic fine particles, conductive fine particles, antioxidants, foaming agents, organic fillers, and inorganic fillers.

[0068] The adhesive layer (Y1) described above has a preferred lower limit of thickness of 200 μm. A thickness of 200 μm or more of the adhesive layer (Y1) improves its adhesive strength to SUS, resulting in superior adhesion of the adhesive sheet of the present invention to SUS. A more preferred lower limit for the thickness of the adhesive layer (Y1) is 250 μm, and an even more preferred lower limit is 300 μm. Furthermore, from the viewpoint of suppressing the load due to the self-weight of the adhesive sheet, the preferred upper limit of the adhesive layer (Y1) is 1000 μm, and the more preferred upper limit is 500 μm.

[0069] The adhesive sheet of the present invention preferably has a 180° peel force of less than 5.0 N / 25 mm on the adhesive layer (Y1) side relative to PTFE (polytetrafluoroethylene). Because the 180° peel force of less than 5.0 N / 25 mm on the adhesive layer (Y1) side relative to PTFE is present, when using the adhesive sheet of the present invention to line a can body with fluororesin, even if the adhesive layer (Y1) and the fluororesin accidentally come into contact during the lining process, contamination of the fluororesin by the adhesive layer (Y1) can be suppressed. Therefore, when using the adhesive sheet of the present invention to line a can body with fluororesin, workability is further improved. A more preferable upper limit for the 180° peel force of the adhesive layer (Y1) side relative to PTFE at 23°C is 3.0 N / 25 mm, and an even more preferable upper limit is 1.0 N / 25 mm. Furthermore, there is no particular preferred lower limit for the 180° peel force against PTFE at 23°C on the adhesive layer (Y1) side, but the practical lower limit is 0.01 N / 25 mm. The 180° peel force against PTFE at 23°C on the adhesive layer (Y1) can be measured by the following method. Specifically, after cutting the adhesive sheet to a size of 25 mm wide x 100 mm long, the adhesive layer (Y1) side is placed on a 2 mm thick polytetrafluoroethylene board (for example, "Yodoflon" manufactured by Yodogawa Hutech Co., Ltd.), and the two are pressed together by moving a 2 kg rubber roller back and forth once at a speed of 300 mm / min. After that, a laminate is created by pressing it under pressure of 0.1 MPa for 10 minutes in an environment of 120 °C. The resulting laminate is subjected to a 180° peel test using a tensile testing machine (for example, "Tensilon" manufactured by ORIENTEC Co., Ltd.) in accordance with JIS Z 0237, under conditions of 23 °C, 50% RH, and a peel speed of 300 mm / min, and the 180° peel force of the adhesive layer (Y1) side to PTFE at 23 °C can be measured by peeling the adhesive sheet from the polytetrafluoroethylene board. Furthermore, if the adhesive sheet of the present invention has an adhesive layer (Y2) described later, a 50 μm thick polyimide (PI) film is placed against the adhesive layer (Y2) side using a 2 kg rubber roller at a speed of 300 mm / min for one pass-through. After cutting the backed adhesive sheet, a laminate is prepared and pressed using the method described above, and a 180° peel test is performed. Furthermore, in this specification, "PTFE" as used in relation to "180° peel force against PTFE" refers to PTFE that has not undergone surface treatment.

[0070] Methods for adjusting the 180° peel force on PTFE at 23°C on the adhesive layer (Y1) side to the range described above include, for example, changing the type or constituent units of the base polymer (P1) (for example, changing the copolymerization ratio or monomer composition of the base polymer (P1)), adjusting the type or content of the tackifying resin (T1), changing the thickness of the adhesive layer (Y1), or changing the substrate.

[0071] The adhesive sheet of the present invention may have layers other than the above-mentioned substrate and the above-mentioned adhesive layer (Y1), as long as the effects of the present invention are not impaired.

[0072] The adhesive sheet of the present invention preferably has an adhesive layer (Y2) formed on the other side of the substrate using an adhesive composition (X2). The presence of the adhesive layer (Y2) in the adhesive sheet of the present invention further improves the workability of the adhesive sheet of the present invention.

[0073] The above adhesive composition (X2) preferably contains a base polymer (P2). Examples of the base polymer (P2) include (meth)acrylic copolymers, styrene elastomers, silicone resins, urethane resins, and synthetic rubbers. In particular, from the viewpoint of easily exhibiting strong adhesion and being able to easily adjust the monomer composition, it is preferable that the base polymer (P2) contains at least one selected from the group consisting of (meth)acrylic copolymers, styrene elastomers, and synthetic rubbers.

[0074] Examples of the (meth)acrylic copolymer, styrene-based elastomer, and synthetic rubber in the above-mentioned base polymer (P2) are the same as those in the above-mentioned base polymer (P1).

[0075] The preferred lower limit for the content of the base polymer (P2) in the adhesive composition (X2) is 50% by mass, and the preferred upper limit is 99% by mass. Having the base polymer (P2) content within this range further improves the adhesive strength of the adhesive layer (Y2). A more preferred lower limit for the base polymer (P2) content is 75% by mass, and a more preferred upper limit is 90% by mass.

[0076] The adhesive composition (X2) preferably contains a tackifying resin (T2). The presence of a tackifying resin (T2) in the adhesive composition (X2) further improves the adhesive strength of the adhesive layer (Y2). From the viewpoint of further improving the adhesive strength of the adhesive layer (Y2), the tackifying resin (T2) preferably contains at least one tackifying resin selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins. Examples of the above-mentioned rosin ester resin, terpene resin, terpene phenol resin, and petroleum resin include those similar to those used in the tackifying resin (T1) described above.

[0077] The preferred lower limit for the content of the tackifying resin (T2) per 100 parts by mass of the base polymer (P2) is 10 parts by mass, and the preferred upper limit is 150 parts by mass. A content of 10 parts by mass or more of the tackifying resin (T2) further improves the adhesive strength of the adhesive layer (Y2). A content of 150 parts by mass or less of the tackifying resin (T2) further improves the flexibility of the adhesive layer (Y2) and further improves the adhesive strength of the adhesive layer (Y2). Furthermore, it becomes easier to adjust the gel fraction of the adhesive layer (Y2) to the range described later, thus the adhesive sheet of the present invention exhibits superior heat resistance. A more preferred lower limit for the content of the tackifying resin (T2) is 15 parts by mass, a more preferred upper limit is 100 parts by mass, a more preferred lower limit is 20 parts by mass, an even more preferred upper limit is 70 parts by mass, and an even more preferred upper limit is 40 parts by mass.

[0078] The adhesive composition (X2) preferably contains a silane coupling agent. The presence of a silane coupling agent in the adhesive composition (X2) further improves the adhesive strength of the adhesive layer (Y2). The silane coupling agent in the adhesive composition (X2) described above is the same as that in the adhesive composition (X1) described above. The silane coupling agents described above may be used individually or in combination of two or more.

[0079] The preferred lower limit for the content of the silane coupling agent per 100 parts by mass of the base polymer (P2) is 0.1 parts by mass, and the preferred upper limit is 5.0 parts by mass. A content of 0.1 parts by mass or more of the silane coupling agent further improves the adhesive strength of the adhesive layer (Y2). A content of 5.0 parts by mass or less of the silane coupling agent can suppress bleed-out of the silane coupling agent. A more preferred lower limit for the content of the silane coupling agent is 0.5 parts by mass, and a more preferred upper limit is 2.0 parts by mass.

[0080] The adhesive composition (X2) described above preferably contains a crosslinking agent. In particular, if the base polymer (P2) contains the (meth)acrylic copolymer, the adhesive composition (X2) preferably contains a crosslinking agent. By containing a crosslinking agent in the adhesive layer (Y2), the (meth)acrylic copolymer forms a crosslinked structure through chemical crosslinking, and the bulk cohesive strength of the adhesive layer (Y2) is further improved. Furthermore, as the gel fraction of the adhesive layer (Y2), described later, becomes larger, the adhesive sheet of the present invention has superior adhesion to SUS and superior heat resistance. Furthermore, from the viewpoint of storage stability, etc., the crosslinking agent may be added to the adhesive composition (X2) immediately before forming the adhesive layer (Y2).

[0081] The crosslinking agent contained in the above adhesive composition (X2) preferably includes at least one selected from the group consisting of isocyanate-based crosslinking agents and epoxy-based crosslinking agents, from the viewpoint of enabling appropriate chemical crosslinking of the (meth)acrylic copolymer and further improving the adhesive strength of the above adhesive layer (Y2). In the adhesive composition (X2) described above, the isocyanate-based crosslinking agent and the epoxy-based crosslinking agent are the same as those in the adhesive composition (X1) described above.

[0082] The preferred lower limit for the content of the crosslinking agent in the adhesive composition (X2) per 100 parts by mass of the (meth)acrylic copolymer is 0.1 parts by mass, and the preferred upper limit is 10 parts by mass. Having the crosslinking agent content within this range allows for appropriate chemical crosslinking of the (meth)acrylic copolymer, further improving the adhesive strength of the adhesive layer (Y2). A more preferred lower limit for the crosslinking agent content is 0.5 parts by mass, and a more preferred upper limit is 5 parts by mass.

[0083] The above adhesive composition (X2) may optionally contain conventionally known fine particles and additives such as inorganic fine particles, conductive fine particles, antioxidants, foaming agents, organic fillers, and inorganic fillers.

[0084] The preferred lower limit for the gel fraction of the adhesive layer (Y2) is 15% by mass, and the preferred upper limit is 60% by mass. When the gel fraction of the adhesive layer (Y2) is 15% by mass or more, the bulk strength of the adhesive layer (Y2) is increased, and the resulting adhesive sheet has superior adhesion. When the gel fraction of the adhesive layer (Y2) is 60% by mass or less, the flexibility of the adhesive layer (Y2) is further improved, and the adhesive strength of the adhesive layer (Y2) is further improved. The more preferred lower limit for the gel fraction of the adhesive layer (Y2) is 25% by mass, and the more preferred upper limit is 50% by mass. The gel fraction of the adhesive layer (Y2) can be measured using the same method as the gel fraction of the adhesive layer (Y1) described above.

[0085] Methods for adjusting the gel fraction of the adhesive layer (Y2) include, for example, changing the type or constituent units of the base polymer (P2) described later (for example, changing the copolymerization ratio or monomer composition of the base polymer (P2)), or adjusting the type or content of the tackifying resin (T2) described later (for example, improving the gel fraction of the adhesive layer (Y2) by reducing the content of the tackifying resin (T2)).

[0086] The preferred lower limit for the thickness of the adhesive layer (Y2) is 200 μm. A thickness of 200 μm or more ensures that the adhesive layer (Y2) has sufficient adhesive strength. A more preferred lower limit for the thickness of the adhesive layer (Y2) is 300 μm. Furthermore, the preferred upper limit for the thickness of the adhesive layer (Y2) is 1000 μm, and the more preferred upper limit is 700 μm.

[0087] The adhesive sheet of the present invention preferably has a 180° peel force against PTFE on the adhesive layer (Y2) side of less than 5.0 N / 25 mm. Having a 180° peel force against PTFE on the adhesive layer (Y2) side of less than 5.0 N / 25 mm allows for the suppression of contamination of the fluororesin by the adhesive layer (Y2) when lining a can body with fluororesin using the adhesive sheet of the present invention, even if the adhesive layer (Y2) accidentally comes into contact with the fluororesin during the lining process. Therefore, workability is further improved when lining a can body with fluororesin using the adhesive sheet of the present invention. A more preferable upper limit for the 180° peel force against PTFE at 23°C on the adhesive layer (Y2) side is 3.0 N / 25 mm, and an even more preferable upper limit is 1.0 N / 25 mm. Furthermore, there is no particular preferred lower limit for the 180° peel force against PTFE at 23°C on the adhesive layer (Y2) side, but the practical lower limit is 0.01 N / 25 mm. The 180° peel force against PTFE at 23°C on the adhesive layer (Y2) can be measured by the following method. Specifically, an adhesive sheet is backed with a 50 μm thick polyimide (PI) film on the adhesive layer (Y1) side by running a 2 kg rubber roller back and forth at a speed of 300 mm / min once. This sheet is then cut to a size of 25 mm wide x 100 mm long. The adhesive layer (Y2) side is then placed on a 2 mm thick polytetrafluoroethylene board (for example, "Yodoflon" manufactured by Yodogawa Hutech Co., Ltd.), and pressed together by running a 2 kg rubber roller back and forth at a speed of 300 mm / min once. After that, the laminate is pressed together by applying pressure at 0.1 MPa for 10 minutes in an environment of 120°C to create a laminate. The resulting laminate can be subjected to a 180° peel test using a tensile testing machine (e.g., ORIENTEC's "Tensilon") in accordance with JIS Z 0237, under conditions of 23°C, 50% RH, and a peeling speed of 300 mm / min. By peeling the adhesive sheet from the polytetrafluoroethylene board, the 180° peel force of the adhesive layer (Y2) against PTFE at 23°C can be measured.

[0088] The adhesive sheet of the present invention has a preferred lower limit of 50 N / 25 mm for the 180° peel force against SUS at 23°C on the adhesive layer (Y2) side. Since the adhesive layer (Y2) has superior adhesive strength when the 180° peel force against SUS at 23°C on the adhesive layer (Y2) side is 50 N / 25 mm or higher, the adhesive sheet of the present invention has higher adhesive properties. The preferred lower limit for the 180° peel force against SUS at 23°C on the adhesive layer (Y2) side after heating is 75 N / 25 mm, and a more preferred lower limit is 100 N / 25 mm. Furthermore, there is no particular preferred upper limit for the 180° peel force against SUS at 23°C on the adhesive layer (Y2) side, but the practical upper limit is 500 N / 25 mm. The 180° peel force on SUS at 23°C on the adhesive layer (Y2) can be measured by the following method. Specifically, by using a 2kg rubber roller and making one back-and-forth motion at a speed of 300mm / min, an adhesive sheet with the adhesive layer (Y1) side backed with a 50μm thick polyimide (PI) film is cut to a size of 25mm wide x 100mm long. Then, the adhesive layer (Y2) side is placed on a SUS plate (SUS304 plate that has been washed with ethanol and then wiped dry), and a laminate is created by pressing it together under pressure at 0.1MPa for 10 minutes in an environment of 120℃. A 180° peel test is performed on the obtained laminate using a tensile testing machine (e.g., ORIENTEC's "Tensilon") in accordance with JIS Z 0237, under conditions of 23℃, 50%RH, and a peeling speed of 300mm / min. By peeling the adhesive sheet from the SUS plate, the 180° peel force of the adhesive layer (Y2) side relative to SUS at 23℃ can be measured.

[0089] Methods for adjusting the 180° peel force on SUS at 23°C on the adhesive layer (Y2) side include, for example, changing the type or constituent units of the base polymer (P2) described later (for example, changing the copolymerization ratio or monomer composition of the base polymer (P2)), adjusting the type or content of the tackifying resin (T2) described later, changing the thickness of the adhesive layer (Y2), or changing the substrate.

[0090] The method for manufacturing the adhesive sheet of the present invention is not particularly limited, and examples include the following methods. First, an adhesive solution (a) containing an adhesive composition (X1) is prepared by adding a base polymer (P1) and, if necessary, a tackifying resin (T1), a crosslinking agent, and a solvent. The obtained adhesive solution (a) is applied to the release treatment surface of a release PET film, and the solvent in the solution is completely dried and removed to create a laminated film in which an adhesive layer (Y1) is formed on the release PET film. The prepared laminated film is placed on a substrate so that the adhesive layer (Y1) and the substrate face each other, and cured for 48 hours in an environment of 40°C and 50%RH to obtain an adhesive sheet having the adhesive layer (Y1) on one side of the substrate. Note that the step of applying the adhesive solution (a) to the release treatment surface of the release PET film may be completed in one step, or it may be performed multiple times by applying it on top of the applied adhesive solution. By adjusting the number of application steps, the thickness of the adhesive layer (Y1) can be easily adjusted. Furthermore, an adhesive solution (b) containing an adhesive composition (X2) is prepared by adding a base polymer (P2) and, if necessary, a tackifying resin (T2), a crosslinking agent, and a solvent. The obtained adhesive solution (b) is applied to the release treatment surface of a release PET film, and the solvent in the solution is completely dried and removed to create a laminated film in which an adhesive layer (Y2) is formed on the release PET film. Then, the adhesive sheet having an adhesive layer (Y1) on one side of the substrate and the side of the substrate without the adhesive layer (Y1) are superimposed so that the adhesive layer (Y2) of the laminated film with the adhesive layer (Y2) formed on the release PET film faces each other, and by curing for 48 hours in an environment of 40°C and 50%RH, an adhesive sheet having an adhesive layer (Y1) on one side of the substrate and an adhesive layer (Y2) on the other side of the substrate can be obtained. The step of applying the adhesive solution (b) to the release treatment surface of the release PET film may be performed only once, or it may be performed multiple times by applying it in layers on top of the applied adhesive solution. By adjusting the number of application steps, the thickness of the adhesive layer (Y2) can be easily adjusted.

[0091] In the manufacturing method of the adhesive sheet of the present invention, it is preferable to surface treat the substrate. By surface treating the substrate, the interlayer strength of the resulting adhesive sheet is further improved, resulting in higher adhesion to SUS. Examples of the above surface treatments include corona treatment, heat cleaning, and silane treatment.

[0092] The gel fraction of the adhesive sheet of the present invention has a preferred lower limit of 10% by mass. Having the gel fraction of the adhesive sheet of the present invention within this range results in superior heat resistance. A more preferred lower limit for the gel fraction of the adhesive sheet of the present invention is 15% by mass, and an even more preferred lower limit is 20% by mass. Furthermore, the gel fraction of the adhesive sheet of the present invention is not particularly limited and may be 100% by mass. The gel fraction of the adhesive sheet of the present invention can be measured by the following method. Specifically, test specimens are prepared by cutting the adhesive sheet to a size of 20 mm in width and 40 mm in length. After removing the release film from the test specimens, they are immersed in a sample tube containing a soluble organic solvent at 23°C for 24 hours. Then, they are removed from the sample tube and dried at 110°C for 1 hour. The mass of the dried test specimens is measured, and the gel fraction is calculated using the following formula (2). Note that the test specimens are not laminated with a release film to protect the adhesive layer. Gel fraction (mass %) = 100 × W4 / W3(2) (W3: Mass of the test specimen before immersion, W4: Mass of the test specimen after immersion and drying) When measuring the gel fraction of an adhesive sheet, the solvent used for immersion should be an appropriate solvent for dissolving the adhesive layer. For example, if the adhesive layer's base polymer is a (meth)acrylic copolymer, ethyl acetate can be used; if the adhesive layer's base polymer is a styrene-based elastomer or synthetic rubber, toluene can be used.

[0093] Furthermore, if the adhesive sheet has adhesive layers on both sides, and the appropriate solvents for eluting the adhesive layer (Y1) and the adhesive layer (Y2) are different (for example, if one base polymer is a (meth)acrylic copolymer and the other base polymer is a styrene elastomer or synthetic rubber), then the gel fraction of the entire adhesive layer in the adhesive sheet should be measured instead of the gel fraction of the adhesive sheet itself. The total gel fraction of the adhesive layer in an adhesive sheet can be measured by the following method. Specifically, each adhesive layer in the adhesive sheet is scraped off from the substrate with a cutter or the like, and each adhesive layer is immersed in an appropriate solvent at 23°C for 24 hours, and then dried at 110°C for 1 hour. Then, using the above-mentioned formula (1), the total gel fraction of the adhesive layer in the adhesive sheet can be calculated by using the sum of the masses of adhesive layer (Y1) and adhesive layer (Y2) after the above procedure as "W1: mass of the test piece after immersion and drying" in formula (1), and setting W0=0.

[0094] Methods for adjusting the gel fraction of the adhesive sheet of the present invention include, for example, adjusting the gel fraction of the adhesive layer (Y1), adjusting the gel fraction of the adhesive layer (Y2), and changing the type of substrate.

[0095] The adhesive sheet of the present invention preferably has a peak in the temperature range of 10°C or higher when the loss tangent (tanδ) (hereinafter sometimes simply referred to as "loss tangent of the adhesive sheet"), measured by a dynamic viscoelasticity measuring device under the conditions of shear mode, heating rate of 5°C / min, and frequency of 10 Hz. The heat resistance of the adhesive sheet of the present invention is further improved when the loss tangent of the adhesive sheet has a peak in the temperature range of 10°C or higher. A more preferable lower limit for the temperature range in which the loss tangent of the adhesive sheet is present (hereinafter simply referred to as "peak temperature of the loss tangent of the adhesive sheet") is 15°C, and an even more preferable lower limit is 20°C. The peak temperature of the loss tangent of the above adhesive sheet can be measured by the following method. Specifically, first, a measurement sample is prepared by cutting the adhesive sheet to a size of 5 mm in width and 20 mm in length. The dynamic viscoelasticity of the obtained measurement sample is measured from -50°C to 200°C using a viscoelastic spectrometer (such as the "DVA-200" manufactured by IT Measurement Control Co., Ltd.) under the conditions of shear mode, heating rate of 5°C / min, and measurement frequency of 10 Hz. The peak temperature of the loss tangent of the adhesive sheet can then be obtained from the obtained dynamic viscoelasticity spectrum.

[0096] Methods for adjusting the peak temperature of the loss tangent of the above-mentioned adhesive sheet include, for example, changing the type and content of the base polymer contained in the adhesive layer (Y1) or the adhesive layer (Y2) (for example, using a (meth)acrylic copolymer having constituent units derived from alkyl (meth)acrylate with a high glass transition temperature), changing the type and content of the tackifying resin contained in the adhesive layer (Y1) or the adhesive layer (Y2) (for example, using a tackifying resin with a high softening point), and changing the type of the substrate.

[0097] The adhesive sheet of the present invention has no particular limitations on its applications, but because it has high adhesion to SUS and excellent heat resistance, it is suitably used to protect adherends, and is particularly suitably used to protect adherends from chemical solutions. Furthermore, because the adhesive sheet of the present invention has high adhesion to SUS, it can suppress planar repulsion with the adherends to which it is bonded and has excellent curved surface conformability, making it suitably used for joining tank bodies and fluororesin in chemical solution tanks, and is even more suitably used for joining tank bodies and fluororesin in chemical solution tanks for semiconductors or chemical industries.

[0098] A laminated sheet having a sheet containing fluororesin on the adhesive layer (Y2) side of the adhesive sheet of the present invention is also one of the present inventions. Since the laminated sheet of the present invention has a sheet containing fluororesin, by using the laminated sheet of the present invention, it is possible to more easily bond fluororesin for various purposes.

[0099] In the laminated sheet of the present invention, examples of sheets containing the above-mentioned fluororesin include sheets containing polytetrafluoroethylene (PTFE), sheets containing perfluoroalkoxyalkane (PFA), sheets containing perfluoroethylenepropene copolymer (FEP), sheets containing ethylenetetrafluoroethylene copolymer (ETFE), sheets containing polyvinylidene fluoride (PVDF), sheets containing polyvinyl fluoride (PVF), sheets containing polychlorotrifluoroethylene (PCTFE), and sheets containing ethylene chlorotrifluoroethylene copolymer (ECTFE). Among these, sheets containing PTFE are preferred because they have excellent heat resistance and chemical resistance.

[0100] The sheet containing the fluororesin preferably has a surface treatment layer on one surface. By having a surface treatment layer on one surface of the sheet containing the fluororesin, the adhesive strength is further improved when the adhesive layer (Y2) is laminated onto the surface treatment layer of the sheet containing the fluororesin, and the laminated sheet of the present invention can bond the fluororesin more firmly. Examples of the above-mentioned surface treatment layers include sodium etching layers, glass backing layers, atmospheric pressure plasma treatment layers, corona treatment layers, flame treatment layers, and embossing layers. In particular, it is preferable that the sheet containing the above-mentioned fluororesin includes at least one surface treatment layer selected from the group consisting of a sodium etching layer, a glass backing layer, and atmospheric pressure plasma treatment on one of its surfaces.

[0101] Examples of sodium etching treatments in the sodium etching layer mentioned above include the naphthalene method and the ammonia method. Examples of glass backing treatments in the above-mentioned glass backing layer include heat lamination of glass cloth using a PFA sheet as a bonding agent.

[0102] The applications of the laminated sheet of the present invention are not particularly limited, but it can be suitably used to bond fluororesin to dissimilar members for various purposes. More specifically, these various purposes include, for example, promoting sliding of friction surfaces, preventing friction of sliding parts, insulating coating, and protecting adherends from high temperatures or chemical solutions. In particular, it can be suitably used to protect adherends, and especially suitably used to protect adherends from chemical solutions. The adherends to be protected from chemical solutions are not particularly limited, but examples include cans, trays, walls, etc. Specifically, it can be suitably used as a coating material for chemical solution tanks such as chemical solution tanks for semiconductors and chemical solution tanks for the chemical industry, as well as for piping for transporting chemical solutions, as a coating material for electronic equipment components, and as a building material. In particular, the laminated sheet of the present invention can be suitably used for lining (surface treatment covering the inner surface of a can) of a can in a chemical solution tank, and even more suitably for lining a can in a chemical solution tank for semiconductors or chemical solution tanks for the chemical industry.

[0103] A chemical tank in which the adhesive sheet or laminated sheet of the present invention is attached to the inner surface of a can body is also one of the present inventions. The chemical tank of the present invention allows for a strong bond of fluororesin to the inner surface of the tank body via the adhesive sheet or laminated sheet of the present invention that is attached to it. This makes it possible to further suppress peeling and lifting of the fluororesin caused by the chemical solution stored in the chemical tank to which the fluororesin is bonded.

[0104] A method for manufacturing a chemical tank, which includes the step of attaching the laminated sheet of the present invention to the inside of the tank body of the chemical tank, is also one of the present inventions.

[0105] A method for manufacturing a chemical tank also includes the steps of: preparing a laminated sheet by pressing a sheet containing fluororesin onto the adhesive layer (Y2) of the adhesive sheet of the present invention; and attaching the adhesive layer (Y1) of the laminated sheet to the inner surface of the can body of the chemical tank.

[0106] In the process of producing the laminated sheet described above, examples of sheets containing the fluororesin include sheets containing polytetrafluoroethylene (PTFE), sheets containing perfluoroalkoxyalkane (PFA), sheets containing perfluoroethylenepropene copolymer (FEP), sheets containing ethylenetetrafluoroethylene copolymer (ETFE), sheets containing polyvinylidene fluoride (PVDF), sheets containing polyvinyl fluoride (PVF), sheets containing polychlorotrifluoroethylene (PCTFE), and sheets containing ethylene chlorotrifluoroethylene copolymer (ECTFE). Among these, sheets containing PTFE are preferred because they have excellent heat resistance and chemical resistance. [Effects of the Invention]

[0107] According to the present invention, it is possible to provide an adhesive sheet that has excellent adhesion to SUS, excellent heat resistance, and also has a superior appearance. Furthermore, according to the present invention, it is possible to provide a laminated sheet having the adhesive sheet. Moreover, according to the present invention, it is possible to provide a chemical tank to which the adhesive sheet or the laminated sheet is attached. In addition, according to the present invention, it is possible to provide a method for manufacturing a chemical tank using the adhesive sheet and the laminated sheet. [Brief explanation of the drawing]

[0108] [Figure 1] This is a schematic diagram illustrating the method for testing the planar rebound properties of adhesive sheets. [Modes for carrying out the invention]

[0109] The embodiments of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0110] (Preparation of acrylic copolymers) (Synthesis Example 1) 100 parts by mass of ethyl acetate was placed in a reactor equipped with a thermometer, stirrer, and condenser, and after purging with nitrogen, the reactor was heated and reflux was started. 30 minutes after the ethyl acetate boiled, 0.08 parts by mass of azobisisobutyronitrile was added as a polymerization initiator. A monomer mixture of the constituent unit monomers shown in Table 1 was then added dropwise and evenly over 1 hour and 30 minutes to allow the reaction to proceed. 30 minutes after the end of the dropwise addition, 0.1 parts by mass of azobisisobutyronitrile was added, and the polymerization reaction was continued for a further 5 hours. By adding ethyl acetate to the reactor and cooling while diluting, a solution of acrylic copolymer with a solid content of 25% by mass was obtained. The obtained acrylic copolymer solution was filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm). The obtained filtrate was supplied to a gel permeation chromatograph (Waters, 2690 Separations Module), and GPC measurements were performed under conditions of sample flow rate of 1 mL / min and column temperature of 40°C to measure the polystyrene-equivalent molecular weight of the acrylic copolymer and determine the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn). A GPC KF-806L column (Showa Denko) was used, and a differential refractometer was used as the detector. The results are shown in Table 1.

[0111] (Synthesis Examples 2-3) An acrylic copolymer was obtained in the same manner as in Synthesis Example 1, except that the monomer mixture was modified as shown in Table 1. The results are shown in Table 1.

[0112] The constituent monomers shown in Table 1 are as follows: BA: n-butyl acrylate 2EHA:2-Ethylhexylacrylate LA: Lauryl acrylate HEA: 2-Hydroxyacrylate AAc: Acrylic acid

[0113] [Table 1]

[0114] (Preparation of tackifying resin) (Synthesis example A) Fifty parts by mass of toluene were added to a reactor equipped with a thermometer, stirrer, and condenser, and after purging with nitrogen, the reactor was heated and reflux was started. After 30 minutes, 2 parts by mass of aluminum chloride (AlCl3) were added while maintaining the toluene at 75°C. A solution of 50 parts by mass of catechol (pyrocatechol) and α-pinene (molar ratio as shown in Table 2) dissolved in 50 parts by mass of toluene was gradually added dropwise over 1 hour and 30 minutes to allow the reaction to proceed. After polymerization for 4 hours, the hydrochloric acid generated from aluminum chloride (AlCl3) was neutralized by cooling while adding 0.1 parts by mass of pyridine to the reactor. The precipitate formed by neutralization was filtered, and after liquid-liquid extraction of the obtained filtrate, the toluene was evaporated to obtain a solid tackifying resin (Synthesis Example A). Regarding the obtained tackifying resin (synthesis example A): 1 ¹H-NMR measurements were performed to confirm that the tackifying resin (synthesis example A) is a copolymer having structural units derived from catechol (pyrocatechol) and structural units derived from α-pinene (a copolymer having structural units derived from catechol (pyrocatechol) in the main chain skeleton or at the ends of the main chain skeleton). The obtained tackifying resin (synthesis example A) was dissolved in tetrahydrofuran, and the resulting solution was filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm). The obtained filtrate was supplied to a gel permeation chromatograph (Waters, 2690 Separations Module), and GPC measurements were performed under conditions of sample flow rate of 1 mL / min and column temperature of 40°C to measure the polystyrene-equivalent molecular weight of the tackifying resin (synthesis example A) and determine the weight-average molecular weight (Mw). A GPC KF-802.5L column (Showa Denko Corporation) was used, and a differential refractometer was used as the detector. The results are shown in Table 2.

[0115] (Measurement of the percentage of bio-derived carbon in tackifying resin (synthesis example A)) The bio-derived carbon content of the obtained tackifying resin (synthesis example A) was measured according to ASTM D6866-22. The results are shown in Table 2.

[0116] [Table 2]

[0117] (Example 1) (1) Preparation of adhesive sheets To 100 parts by mass of the solid content of the acrylic copolymer (Synthesis Example 1) obtained as the base polymer (P1), 20 parts by mass of rosin ester resin (Arakawa Chemical Industries, Ltd., "Pine Crystal KE-359") and 10 parts by mass of terpene phenol resin (Yasuhara Chemical Co., Ltd., "YS Polystar G150") were added as tackifying resins (T1). Furthermore, 30 parts by mass of ethyl acetate (Fuji Chemical Co., Ltd.) and 1.0 part by mass of isocyanate crosslinking agent (Covestro, Inc., "Desmodule L-75") were added, and the mixture was thoroughly stirred to obtain an adhesive solution (a) containing the adhesive composition (X1). The obtained adhesive solution (a) was applied to the release surface of a 75 μm thick release PET film (Toyo Cloth Co., Ltd., "SP3000"), and dried at 100°C for 5 minutes to form a 200 μm thick adhesive layer (Y1) on the release PET film, thereby producing a laminated film (a). A 300 μm thick glass cloth (manufactured by Nitto Boseki Co., Ltd., "KS2770") was prepared as the base material. The prepared laminated film was then placed on top of the base material so that the adhesive layer (Y1) faced the base material, and cured by heating at 40°C for 48 hours. This resulted in a laminate having the base material and the adhesive layer (Y1) on one side of the base material. Furthermore, to 100 parts by mass of the solid content of the acrylic copolymer (Synthesis Example 1) obtained as the base polymer (P2), 20 parts by mass of a rosin ester resin (Arakawa Chemical Industries, Ltd., "Pine Crystal KE-359") and 10 parts by mass of a terpene phenol resin (Yasuhara Chemical Co., Ltd., "YS Polystar G150") were added. In addition, 30 parts by mass of ethyl acetate (Fuji Chemical Co., Ltd.) and 1.0 part by mass of an isocyanate crosslinking agent (Covestro, Inc., "Desmodule L-75") were added, and the mixture was thoroughly stirred to obtain an adhesive solution (b) containing the adhesive composition (X2). The obtained adhesive solution (b) was applied to the release surface of a 75 μm thick release PET film (Toyo Cloth Co., Ltd., "SP3000"), and dried at 100°C for 5 minutes to form a 50 μm thick adhesive layer (Y2) on the release PET film, thereby producing a laminated film (b). In a laminate having a substrate and an adhesive layer (Y1) on one side of the substrate, the side of the substrate without the adhesive layer (Y1) and the adhesive layer (Y2) of the laminated film (b) were superimposed so that they faced each other, and cured for 48 hours in an environment of 40°C and 50%RH to obtain an adhesive sheet having a substrate, an adhesive layer (Y1) on one side of the substrate and an adhesive layer (Y2) on the other side of the substrate.

[0118] (2) Measurement of the gel fraction of the adhesive layer (Y1) The adhesive layer (Y1) was extracted from the obtained adhesive sheet by cutting it with a cutter, and its mass (W1 (g)) was measured. The obtained test specimen was immersed in ethyl acetate at 23°C for 24 hours, then removed from the ethyl acetate and dried at 110°C for 1 hour. The mass (W2 (g)) of the dried test specimen was measured, and the gel fraction of the adhesive layer (Y1) was calculated using formula (1) above, with W0 set to 0. The results are shown in Table 3.

[0119] (3) Measurement of the gel fraction of the adhesive layer (Y2) The adhesive layer (Y2) was extracted from the obtained adhesive sheet by cutting it with a cutter, and its mass (W1 (g)) was measured. The obtained test specimen was immersed in ethyl acetate at 23°C for 24 hours, then removed from the ethyl acetate and dried at 110°C for 1 hour. The mass (W2 (g)) of the dried test specimen was measured, and the gel fraction of the adhesive layer (Y2) was calculated using formula (1) above, with W0 set to 0. The results are shown in Table 3.

[0120] (4) 180° peel force on SUS at 23°C on the adhesive layer (Y1) side The obtained adhesive sheet was backed with an adhesive layer (Y2) by rolling a 2kg rubber roller back and forth once at a speed of 300mm / min with a 50μm thick polyimide (PI) film, and then cut to a size of 25mm wide x 100mm long. Next, the cut adhesive sheet was placed with the adhesive layer (Y1) side facing a 1mm thick SUS plate (SUS304 plate washed with ethanol and then wiped dry), and after rolling a 2kg rubber roller back and forth once at a speed of 300mm / min, a laminate was fabricated by pressing it under pressure at 0.1MPa for 10 minutes in an environment of 120℃. The obtained laminates were subjected to a 180° peel test using a tensile testing machine (ORIENTEC, "Tensilon") in accordance with JIS Z 0237, under conditions of 23°C, 50% RH, and a peeling speed of 300 mm / min. The 180° peel force against SUS at 23°C on the heated adhesive layer (Y1) was measured by peeling the adhesive sheet from the SUS plate. The results are shown in Table 3.

[0121] (5) Measurement of 180° peel force against PTFE at 23°C on the adhesive layer (Y1) side. The obtained adhesive sheet was backed with an adhesive layer (Y2) by passing a 2kg rubber roller over it once at a speed of 300mm / min with a 50μm thick polyimide (PI) film, and then cut to a size of 25mm wide x 100mm long. The adhesive layer (Y1) side of the cut adhesive sheet was pressed onto a 2mm thick polytetrafluoroethylene sheet (Yodogawa Hutech Co., Ltd., "Yodoflon") by passing a 2kg rubber roller over it once at a speed of 300mm / min with a 2mm thick polytetrafluoroethylene sheet, and then pressed further by applying pressure at 0.1MPa for 10 minutes in an environment of 120℃ to create a laminate. The obtained laminates were subjected to a 180° peel test using a tensile testing machine (ORIENTEC, "Tensilon") in accordance with JIS Z 0237, at 23°C and a peeling speed of 300 mm / min. The 180° peel force of the adhesive layer (Y1) against PTFE at 23°C was measured by peeling the adhesive layer (Y1) from the polytetrafluoroethylene film. The results are shown in Table 3.

[0122] (6) 180° peel force of the adhesive layer (Y2) against SUS at 23°C The obtained adhesive sheet was backed with an adhesive layer (Y1) by passing a 50 μm thick polyimide (PI) film back and forth with a 2 kg rubber roller at a speed of 300 mm / min, and then cut to a size of 25 mm wide x 100 mm long. Next, the cut adhesive sheet was placed with the adhesive layer (Y1) side facing a 1 mm thick SUS plate (SUS304 plate that had been washed with ethanol and then wiped dry), and a laminate was fabricated by pressing it under pressure at 0.1 MPa for 10 minutes in an environment of 120°C. The obtained laminates were subjected to a 180° peel test using a tensile testing machine (ORIENTEC, "Tensilon") in accordance with JIS Z 0237, under conditions of 23°C, 50% RH, and a peeling speed of 300 mm / min. The 180° peel force against SUS at 23°C on the heated adhesive layer (Y2) was measured by peeling the adhesive sheet from the SUS plate. The results are shown in Table 3.

[0123] (7) Measurement of 180° peel force against PTFE at 23°C on the adhesive layer (Y2) side. The obtained adhesive sheet was backed with an adhesive layer (Y1) by passing a 50 μm thick polyimide (PI) film back and forth with a 2 kg rubber roller at a speed of 300 mm / min, and then cut to a size of 25 mm wide x 100 mm long. The adhesive layer (Y2) side of the cut adhesive sheet was pressed onto a 2 mm thick polytetrafluoroethylene sheet (Yodogawa Hutech Co., Ltd., "Yodoflon") by passing a 2 kg rubber roller back and forth at a speed of 300 mm / min, and then a laminate was fabricated by further pressing it under pressure at 0.1 MPa for 10 minutes in an environment of 120°C. The obtained laminates were subjected to a 180° peel test using a tensile testing machine (ORIENTEC, "Tensilon") in accordance with JIS Z 0237, under conditions of 23°C and a peeling speed of 300 mm / min. The 180° peel force of the adhesive layer (Y2) against PTFE at 23°C was measured by peeling the adhesive layer (Y2) from the polytetrafluoroethylene film. The results are shown in Table 3.

[0124] (8) Measurement of the gel fraction of the adhesive sheet The obtained adhesive sheet was cut into a flat rectangular shape measuring 50 mm wide x 100 mm long to prepare test specimens, and their mass (W3 (g)) was measured. The obtained test specimens were immersed in a sample tube containing ethyl acetate at 23°C for 24 hours, then removed from the sample tube and dried at 110°C for 1 hour. The mass (W4 (g)) of the dried test specimens was measured, and the gel fraction of the adhesive sheet was calculated using formula (2) above. The results are shown in Table 3.

[0125] (9) Measurement of the peak temperature of the loss tangent of the adhesive sheet The obtained adhesive sheet was cut into a rectangular shape measuring 50 mm wide x 100 mm long to prepare test specimens. The dynamic viscoelastic spectrum of the prepared test specimens was measured from -50°C to 200°C using a viscoelastic spectrometer (IT Measurement Control Co., Ltd., "DVA-200") under shear mode, heating rate of 5°C / min, and measurement frequency of 10 Hz. The peak temperature of the loss tangent of the adhesive sheet was then obtained from the resulting dynamic viscoelastic spectrum. The results are shown in Table 3.

[0126] (Examples 2-12, 16-17, Comparative Examples 1-7) In the above-described "(1) Preparation of adhesive sheet," an adhesive sheet was prepared and measured in the same manner as in Example 1, except that the composition of the adhesive composition (X1), the thickness of the adhesive layer (Y1), the type and thickness of the substrate, the composition of the adhesive composition (X2), and the thickness of the adhesive layer (Y2) were as shown in Tables 3 to 5. The results are shown in Tables 3 to 5.

[0127] (Example 13) In the above-mentioned "(1) Preparation of adhesive sheet," the composition of the adhesive composition (X1), the thickness of the adhesive layer (Y1), the composition of the adhesive composition (X2), and the thickness of the adhesive layer (Y2) were as shown in Table 4. Furthermore, the adhesive sheet was prepared in the same manner as in Example 1, except that corona treatment was performed on both surfaces of the substrate shown in Table 4 using TEC-4AX (manufactured by Kasuga Electric Co., Ltd.) under the conditions of 100W, 2m / min, and a treatment width of 300mm.

[0128] Furthermore, in Example 13, since the solvents that readily elute the base polymer of adhesive layer (Y1) and the base polymer of adhesive layer (Y2) are different, the gel fraction of the entire adhesive layer in the adhesive sheet was measured instead of the gel fraction of the adhesive sheet itself. Specifically, adhesive layers (Y1) and (Y2) were removed from the substrate using a cutter, adhesive layer (Y1) was immersed in ethyl acetate and adhesive layer (Y2) in toluene at 23°C for 24 hours, then removed from the organic solvents and dried at 110°C for 1 hour. Then, using the above-mentioned formula (1), the total gel fraction of the adhesive layer in the adhesive sheet was measured by calculating W0=0, using the sum of the masses of adhesive layer (Y1) and adhesive layer (Y2) after the above procedure as "W1: mass of the test piece after immersion and drying" in formula (1). Other measurements were performed in the same manner as in Example 1. The results are shown in Table 4.

[0129] (Example 14) In the above-described "(1) Preparation of adhesive sheet," the composition of the adhesive composition (X1), the thickness of the adhesive layer (Y1), the composition of the adhesive composition (X2), and the thickness of the adhesive layer (Y2) were as shown in Table 4. Furthermore, the substrate shown in Table 4 was heated at 300°C for 24 hours and heat-cleaned. Except for these modifications, an adhesive sheet was prepared and measured in the same manner as in Example 1. The results are shown in Table 4.

[0130] (Examples 15, 18) In the above-mentioned "(1) Preparation of adhesive sheet," the composition of the adhesive composition (X1), the thickness of the adhesive layer (Y1), the type and thickness of the substrate, the composition of the adhesive composition (X2), and the thickness of the adhesive layer (Y2) were as shown in Table 4. After curing for 48 hours in an environment of 40°C and 50%RH, the adhesive sheet was prepared and measured in the same manner as in Example 1, except that an electron beam with an acceleration voltage of 175kV was irradiated from both sides of the adhesive sheet to an irradiation dose of 100kGy. For the above-mentioned "(2) Measurement of gel fraction of adhesive layer (Y1)," "(3) Measurement of gel fraction of adhesive layer (Y2)," and "(8) Measurement of gel fraction of adhesive sheet," the test specimens were immersed in toluene instead of ethyl acetate. The results are shown in Table 4.

[0131] <Rating> The obtained adhesive sheets were evaluated using the following method. The results are shown in Tables 3-5.

[0132] (Plane rebound properties) The obtained adhesive sheet was cut to a size of 20 mm wide x 200 mm long. The adhesive layer (Y1) side was then bonded to a SUS plate (SUS304 plate cleaned with ethanol and then wiped dry) measuring 20 mm wide, 200 mm long, and 1 mm thick, and a 2 kg rubber roller was passed back and forth once at a speed of 300 mm / min. Next, the adhesive layer (Y2) was bonded to a polytetrafluoroethylene plate (manufactured by Yoshida SKT Co., Ltd., "TEFPASS Etching Sheet", 50 mm wide, 125 mm long, and 3 mm thick) whose surface had been treated with sodium etching. At this time, the adhesive sheet was adjusted to be located in the center of the length direction of the polytetrafluoroethylene plate. The polytetrafluoroethylene plate and the SUS plate were then bonded together via the adhesive sheet by passing a 2 kg rubber roller back and forth once at a speed of 300 mm / min on the polytetrafluoroethylene plate, and a laminate was fabricated by pressing it under pressure at 0.1 MPa for 10 minutes in an environment of 120°C. The resulting laminate was mounted on a jig as shown in Figure 1, and bending stress was applied in the longitudinal direction of the laminate to deform it into an arc shape such that the distance between the ends of the polytetrafluoroethylene sheets in the longitudinal direction was 190 mm and the height of the curved laminate was 30 mm. In this state, the laminate was placed in a constant temperature oven at 120°C and left undisturbed for 24 hours. The laminate was removed from the oven while still in its arc shape, and the peel height H (mm) between the adhesive sheet and the SUS plate was measured with calipers. Planar rebound properties were evaluated according to the following criteria. ◎: If the peeling height H is 5.0 mm or less ○: If the peeling height H exceeds 5.0 mm but is 10 mm or less. ×: If the peeling height Hg exceeds 10mm

[0133] (Appearance of the adhesive sheet) The adhesive sheets obtained in "(1) Preparation of adhesive sheets" described above were visually inspected on the surface of the adhesive layer (Y1), and the appearance of the adhesive sheets was evaluated according to the following criteria. ○: If no air bubbles are present on the surface of the adhesive layer (Y1) ×: If air bubbles are present on the surface of the adhesive layer (Y1)

[0134] (Adhesive residue on PTFE) After the 180° peel test of the adhesive sheet in "(5) Measurement of 180° peel force against PTFE at 23°C on the adhesive layer (Y1) side" described above, the surface of the PTFE board after peeling the adhesive sheet was visually observed, and the amount of adhesive residue on the PTFE was evaluated according to the following criteria. ○: When no adhesive residue is present on the surface of the PTFE board after the adhesive sheet has been removed. ×: If adhesive residue is present on the surface of the PTFE board after the adhesive sheet has been removed. Even if the evaluation result is "×", it can still be used without problems depending on the application.

[0135] [Table 3]

[0136] [Table 4]

[0137] [Table 5] [Industrial applicability]

[0138] According to the present invention, it is possible to provide an adhesive sheet that has excellent adhesion to SUS, excellent heat resistance, and also has a superior appearance. Furthermore, according to the present invention, it is possible to provide a laminated sheet having the adhesive sheet. Moreover, according to the present invention, it is possible to provide a chemical tank to which the adhesive sheet or the laminated sheet is attached. In addition, according to the present invention, it is possible to provide a method for manufacturing a chemical tank using the adhesive sheet and the laminated sheet. [Explanation of Symbols]

[0139] 1 Adhesive sheet 2 SUS board 3. Polytetrafluoroethylene sheet 4 Laminate 5. Jig

Claims

1. An adhesive sheet having a base material and an adhesive layer (Y1) formed on one surface of the base material using an adhesive composition (X1), The substrate is composed of at least one selected from the group consisting of nonwoven fabric, a substrate having a mesh structure, and a foam having an open-cell structure. The adhesive layer (Y1) has a gel fraction of 10% by mass or more. The adhesive sheet has a 180° peel force of 50 N / 25 mm or more on the adhesive layer (Y1) side against SUS at 23°C. An adhesive sheet characterized by the following features.

2. The adhesive sheet according to claim 1, wherein the thickness of the adhesive layer (Y1) is 200 μm or more.

3. The adhesive sheet according to claim 1 or 2, wherein the 180° peel force on the PTFE side of the adhesive layer (Y1) is less than 5.0 N / 25 mm.

4. The adhesive composition (X1) contains a base polymer (P1), The base polymer (P1) includes at least one selected from the group consisting of (meth)acrylic copolymers, styrene elastomers, and synthetic rubbers. The adhesive sheet according to claim 1 or 2.

5. The adhesive sheet according to claim 1 or 2, wherein the adhesive composition (X1) contains a tackifying resin (T1).

6. The adhesive sheet according to claim 5, wherein the tackifying resin (T1) comprises at least one tackifying resin selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins.

7. The adhesive sheet according to claim 5, wherein the content of the tackifying resin (T1) is 10 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the base polymer (P1).

8. The adhesive sheet according to claim 1 or 2, wherein the adhesive composition (X1) contains a silane coupling agent.

9. The adhesive sheet according to claim 8, wherein the silane coupling agent comprises a silane coupling agent having at least one functional group selected from the group consisting of epoxy group, amino group, vinyl group, acrylic group, methacrylic group, isocyanate group, isocyanurate group, styryl group, ureido group, acid anhydride group, and mercapto group.

10. The adhesive sheet according to claim 8, wherein the content of the silane coupling agent is 0.1 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of the base polymer (P1).

11. The adhesive sheet according to claim 1 or 2, wherein the thickness of the substrate is 50 μm or more and 1000 μm or less.

12. Furthermore, the adhesive sheet according to claim 1, further comprising an adhesive layer (Y2) made of an adhesive composition (X2) on the other surface of the substrate.

13. The adhesive sheet according to claim 12, wherein the thickness of the adhesive layer (Y2) is 200 μm or more.

14. The adhesive sheet according to claim 12 or 13, wherein the 180° peel force on the PTFE side of the adhesive layer (Y2) is less than 5.0 N / 25 mm.

15. The adhesive composition (X2) contains a base polymer (P2), The base polymer (P2) includes at least one selected from the group consisting of (meth)acrylic copolymers, styrene elastomers, and synthetic rubbers. The adhesive sheet according to claim 12 or 13.

16. The adhesive sheet according to claim 1 or 2, wherein the loss tangent (tanδ), measured by a dynamic viscoelasticity measuring device under the conditions of shear mode, heating rate of 5°C / min, and frequency of 10 Hz, has a peak in the temperature range of 10°C or higher.

17. The adhesive sheet according to claim 1 or 2, used for lining the body of a chemical tank.

18. A laminated sheet according to claim 12, wherein the adhesive sheet has a sheet containing fluororesin on a surface different from the surface of the adhesive layer (Y2) that is in contact with the substrate.

19. The laminated sheet according to claim 18, wherein the sheet containing the fluororesin has at least one surface treatment layer selected from the group consisting of a sodium etching layer, a glass backing layer, and an atmospheric pressure plasma treatment layer on one of its surfaces.

20. A laminated sheet according to claim 18, used for protecting an adherend.

21. A laminated sheet according to claim 20, used to protect an adherend from a chemical solution.

22. A chemical tank having the adhesive sheet described in claim 1, or the laminated sheet described in claim 18, attached to the inner surface of a can body.

23. A method for manufacturing a chemical tank, comprising the step of attaching the laminated sheet described in claim 18 to the inner surface of the tank body of the chemical tank.

24. A method for manufacturing a chemical tank, comprising the steps of: manufacturing a laminated sheet using the adhesive sheet described in claim 12 or 13, and pressing a sheet containing fluororesin onto the adhesive layer (Y2); and attaching the adhesive layer (Y1) of the laminated sheet to the inner surface of the tank body of the chemical tank.

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