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

Abstract

This invention provides an adhesive tape that offers excellent workability and reliability when bonding fluororesin to a can or the like. It also provides a laminated sheet having the adhesive tape. Furthermore, it provides a chemical tank to which the adhesive tape or the laminated sheet is attached. In addition, it provides a method for manufacturing a chemical tank using the adhesive tape and the laminated sheet. [Solution] An adhesive tape comprising a base material, an adhesive layer (Y1) formed on one side of the base material using an adhesive composition (X1), and an adhesive layer (Y2) formed on the other side of the base material using an adhesive composition (X2), wherein the adhesive tape has a thickness of 250 μm or more, and after backing the adhesive layer (Y2) with a PET film with a thickness of 50 μm, the adhesive layer (Y1) is bonded to a polytetrafluoroethylene board, and the laminate A obtained by standing at 23°C for 24 hours is JIS Z In accordance with JIS Z 0237, the 180° peel force of the adhesive layer (Y1) against the polytetrafluoroethylene plate, measured at 23°C and a peeling speed of 300 mm / min, is 5 N / 25 mm or more. The adhesive tape is obtained by backing the adhesive layer (Y1) with a 1.0 mm thick polytetrafluoroethylene plate, then bonding the adhesive layer (Y2) to a SUS304 plate, and heating at 120°C for 1 hour, wherein the 180° peel force of the adhesive layer (Y2) against the SUS304 plate, measured at 23°C and a peeling speed of 30 mm / min, is 40 N / 25 mm or more.

Description

[Technical Field]

[0001] This invention relates to an adhesive tape. Furthermore, it relates to a laminated sheet having the adhesive tape. Moreover, it relates to a chemical tank to which the adhesive tape or the laminated sheet is attached. In addition, this invention relates to a method for manufacturing a chemical tank using the adhesive tape and the laminated sheet. [Background technology]

[0002] Conventionally, adhesive tape has been widely used to fix various components. Specifically, for example, adhesive tape is used to adhere a cover panel to protect the surface of a portable electronic device to a touch panel module or display panel module, or to bond a touch panel module to a display panel module. In addition to high adhesiveness, adhesive tape used to fix such components is required to have functions such as heat resistance, thermal conductivity, and impact resistance, depending on the environment in which it is used (for example, Patent Documents 1 to 3). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-052050 [Patent Document 2] Japanese Patent Publication No. 2015-021067 [Patent Document 3] Japanese Patent Publication No. 2015-120876 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In recent years, the demand for fluororesins has been increasing in various fields due to their excellent heat resistance, chemical resistance, low dielectric properties, and water repellency. For example, polytetrafluoroethylene (PTFE) is used in a wide range of applications, such as wire insulation 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, these adhesives cannot achieve sufficient bonding strength without pre-treatment of the fluororesin surface. Typically, pre-treatment, such as chemical etching, is applied to the fluororesin to improve bonding strength. Such pre-treatment is not only expensive but also presents challenges in terms of quality degradation, safety, and environmental impact. Therefore, there is a need for an alternative adhesive tape that can bond without pre-treatment.

[0006] On the other hand, when using adhesive tape to bond the fluororesin to the can body, there are problems such as reduced workability due to wrinkles forming when bonding large areas of adhesive tape, and reduced reliability of the lining due to void formation between the fluororesin and the can body due to thermal expansion, or insufficient adhesive strength.

[0007] The present invention provides an adhesive tape that offers excellent workability and reliability when bonding fluororesin to a can or the like. The present invention also provides a laminated sheet having the adhesive tape. Furthermore, the present invention provides a chemical tank to which the adhesive tape or the laminated sheet is attached. In addition, the present invention provides a method for manufacturing a chemical tank using the adhesive tape and the laminated sheet. [Means for solving the problem]

[0008] The present disclosure 1 is an adhesive tape having a base material, an adhesive layer (Y1) formed on one surface of the base material using an adhesive composition (X1), and an adhesive layer (Y2) formed on the other surface of the base material using an adhesive composition (X2). The adhesive tape has a thickness of 250 μm or more. After backing the adhesive layer (Y2) with a PET film having a thickness of 50 μm, the adhesive layer (Y1) is bonded to a polytetrafluoroethylene plate and left standing at 23° C. for 24 hours. For the laminate A thus obtained, in accordance with JIS Z 0237, the 180° peel force of the adhesive layer (Y1) side with respect to the polytetrafluoroethylene plate measured under the conditions of 23° C. and a peel rate of 300 mm / min is 5 N / 25 mm or more. After backing the adhesive layer (Y1) with a polytetrafluoroethylene plate having a thickness of 1.0 mm, the adhesive layer (Y2) is bonded to a SUS304 plate and heated at 120° C. for 1 hour. For the laminate B thus obtained, in accordance with JIS Z 0237, the 180° peel force of the adhesive layer (Y2) side with respect to the SUS304 plate measured under the conditions of 23° C. and a peel rate of 30 mm / min is 40 N / 25 mm or more. The present disclosure 2 is the adhesive tape of the present disclosure 1, wherein the adhesive composition (X1) contains a base polymer (P1), and the base polymer (P1) contains at least one selected from the group consisting of a (meth)acrylic copolymer and a styrene-based elastomer. The present disclosure 3 is the adhesive tape of the present disclosure 1 or 2, wherein the adhesive composition (X1) contains an adhesion-imparting resin (T1). The present disclosure 4 is the adhesive tape of the present disclosure 3, wherein the adhesion-imparting resin (T) contains an adhesion-imparting resin (T1-1) having at least one structural unit (A) selected from the group consisting of a structural unit (A-1), a structural unit (A-1'), a structural unit (A-2), a structural unit (A-2'), a structural unit (A-3), a structural unit (A-3'), a structural unit (A-4), and a structural unit (A-4') represented by the following formula. In the present disclosure 5, the tackifier resin (T1) contains at least one tackifier resin (T1-2) selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins, and is the adhesive tape of the present disclosure 3 or 4. In the present disclosure 6, the adhesive composition (X1) contains a crosslinking agent, and is the adhesive tape of the present disclosure 1, 2, 3, 4, or 5. In the present disclosure 7, the crosslinking agent contains at least one selected from the group consisting of isocyanate-based crosslinking agents and epoxy-based crosslinking agents, and is the adhesive tape of the present disclosure 6. In the present disclosure 8, the adhesive layer (Y1) has a gel fraction of 15% by mass or more and 60% by mass or less, and is the adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, or 7. In the present disclosure 9, the adhesive layer (Y1) has a thickness of 50 μm or more and 1000 μm or less, and is the adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, or 8. In the present disclosure 10, the adhesive composition (X2) contains a base polymer (P2), and the base polymer (P2) contains at least one selected from the group consisting of (meth)acrylic copolymers and styrene-based elastomers, and is the adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, or 9. In the present disclosure 11, the adhesive composition (X2) contains a tackifier resin (T2), and the tackifier resin (T2) contains at least one tackifier resin selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins, and is the adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In the present disclosure 12, the adhesive composition (X2) contains a silane coupling agent, and is the adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11. In the present disclosure 13, the adhesive composition (X2) contains a crosslinking agent, and is the adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12. In the present disclosure 14, the crosslinking agent contains at least one selected from the group consisting of isocyanate-based crosslinking agents and epoxy-based crosslinking agents, and is the adhesive tape of the present disclosure 13. Disclosure 15 is an adhesive tape according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14, wherein the adhesive layer (Y2) has a gel fraction of 15% by mass or more and 60% by mass or less. Disclosure 16 is an adhesive tape according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15, wherein the adhesive layer (Y2) has a probe tack value of 20 N / 5 mmφ or more, measured under the conditions of 23°C, pressurized pressure of 98 gf, pressurizing speed of 100 mm / sec, pressurizing time of 10 seconds, and release speed of 5 mm / sec. Disclosure 17 is an adhesive tape according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16, wherein the adhesive layer (Y2) has a thickness of 50 μm or more and 1000 μm or less. Disclosure 18 is an adhesive tape according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 17, in which the substrate contains at least one selected from the group consisting of polyester resin, polyimide resin, polyether resin, polyolefin resin, polyurethane resin, metal, glass fiber, and carbon fiber. Disclosure 19 is an adhesive tape of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18, wherein the substrate is a substrate of at least one shape selected from the group consisting of nonwoven fabric and woven fabric. Disclosure 20 is an adhesive tape of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19, wherein the substrate has a thickness of 50 μm or more and 1000 μm or less. Disclosure 21 is an adhesive tape according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, wherein the 180° peel force from the adhesive layer (Y2) to the SUS304 plate is 20 N / 25 mm or more, measured in accordance with JIS Z 0237 under conditions of 80°C and a peeling speed of 30 mm / min, for a laminate B obtained by backing the adhesive layer (Y1) with a 1.0 mm thick polytetrafluoroethylene plate, then bonding the adhesive layer (Y2) to a SUS304 plate, and heating at 120°C for 1 hour. Disclosure 22 is an adhesive tape of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21 used for lining the can body in chemical tanks for semiconductors or chemical tanks for the chemical industry. Disclosure 23 is a laminated sheet having a sheet containing fluororesin on the adhesive layer (Y1) side of the adhesive tape of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 or 22. Disclosure 24 is a laminated sheet of Disclosure 23 used to protect an adherend. Disclosure 25 is a laminated sheet of Disclosure 24 used to protect an adherend from a chemical solution. Disclosure 26 is a chemical tank in which the adhesive tape of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22, or the laminated sheet of Disclosure 23, 24, or 25 is attached to the inner surface of the can body. Disclosure 27 is a method for manufacturing a chemical tank, comprising the steps of: preparing a laminated sheet according to Disclosure 23, 24, or 25 by pressing a sheet containing fluororesin onto the adhesive layer (Y1) of the adhesive tape according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22; and attaching the adhesive layer (Y2) of the laminated sheet to the inner surface of the can body of the chemical tank.

[0009] [ka]

[0010] [ka]

[0011] [ka]

[0012] [ka]

[0013] In the formula, R 1 ~R 7 * represents a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a group having a polar functional group. n and l represent integers between 2 and 4, respectively, and n' and l' represent integers between 2 and 5, respectively. m and k represent integers between 1 and 4, respectively, and m' and k' represent integers between 1 and 5, respectively. * represents a linking part. The present invention will be described in detail below.

[0014] The inventors of the present invention investigated the following: for an adhesive tape having a base material, an adhesive layer (Y1) on one side of the base material, and an adhesive layer (Y2) on the other side of the base material, they adjusted the thickness to be above a specific value, and then set the 180° peel strength of the adhesive layer (Y1) side against a polytetrafluoroethylene plate at 23°C to be above a specific value, and the 180° peel strength of the adhesive layer (Y2) side against a SUS304 plate at 23°C to be above a specific value. As a result, they found that an adhesive tape with excellent workability and reliability when bonding fluororesin to cans and the like could be obtained, and thus completed the present invention.

[0015] The adhesive tape of the present invention comprises a base material, an adhesive layer (Y1) formed on one side of the base material using an adhesive composition (X1), and an adhesive layer (Y2) formed on the other side of the base material using an adhesive composition (X2).

[0016] The adhesive tape of the present invention has a minimum thickness of 250 μm. Having a thickness of 250 μm or more allows the adhesive tape of the present invention to achieve a high level of both adhesive strength and ease of application. A preferred minimum thickness for the adhesive tape of the present invention is 300 μm, and a more preferred minimum thickness is 400 μm. Furthermore, from the viewpoint of reducing the load due to the self-weight of the adhesive tape, the preferred upper limit for the thickness of the adhesive tape of the present invention is 1200 μm, and the more preferred upper limit is 1000 μm. The thickness of the adhesive tape of the present invention may be less than 1000 μm, or 800 μm or less. The thickness of the adhesive tape of the present invention may be 250 μm to 1200 μm, 300 μm to 1000 μm, or 400 μm to 800 μm.

[0017] The adhesive tape of the present invention is obtained by backing the adhesive layer (Y2) with a 50 μm thick corona-treated PET film, then laminating the adhesive layer (Y1) to a polytetrafluoroethylene board, and leaving it to stand at 23°C for 24 hours. For the resulting laminate A, the lower limit of the 180° peel force of the adhesive layer (Y1) relative to the polytetrafluoroethylene board (hereinafter also referred to as "the 180° peel force of the adhesive layer (Y1) relative to PTFE at 23°C") is 5 N / 25 mm, measured 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 (Y1) relative to PTFE at 23°C is 5 N / 25 mm or higher, which provides excellent adhesion to fluororesins for the adhesive tape of the present invention. A preferred lower limit for the 180° peel force of the adhesive layer (Y1) relative to PTFE at 23°C is 7 N / 25 mm, and a more preferred lower limit is 10 N / 25 mm. Furthermore, there is no particular preferred upper limit for the 180° peel force of the adhesive layer (Y1) against PTFE at 23°C, but the practical upper limit is 100 N / 25 mm. The 180° peel force of the adhesive layer (Y1) above against PTFE at 23°C may be 5N / 25mm to 100N / 25mm, 7N / 25mm to 100N / 25mm, or 10N / 25mm to 100N / 25mm. In this specification, the term "adhesion" refers not only to a permanent bonding phenomenon but also to a temporary bonding phenomenon called "tackiness."

[0018] The 180° peel force of the above adhesive layer (Y1) against PTFE at 23°C can be measured by the following method. Specifically, an adhesive tape with the adhesive layer (Y2) backed using a 50 μm thick PET film is cut to a size of 25 mm wide x 100 mm long. Then, the adhesive layer (Y1) side is placed on a 2 mm thick polytetrafluoroethylene board (for example, "Yodoflon PTFE (F4) Film Sheet 4400" manufactured by Yodogawa Hutech Co., Ltd.), and pressed together by moving a 2 kg rubber roller back and forth once at a speed of 300 mm / min. After that, the laminate A is produced by curing it for 24 hours in an environment of 23°C and 50% RH. For the obtained laminate A, a 180° peel test is performed using a tensile testing machine (e.g., "Tensilon" manufactured by ORIENTEC) 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 tape from the polytetrafluoroethylene board, the 180° peel force of the adhesive layer (Y1) relative to PTFE at 23°C can be measured.

[0019] Methods for adjusting the 180° peel force of the adhesive layer (Y1) to PTFE at 23°C to within the range described above 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.

[0020] The adhesive tape of the present invention is prepared by backing the adhesive layer (Y1) with a 1.0 mm thick polytetrafluoroethylene board, then bonding the adhesive layer (Y2) to a SUS304 board, and heating the laminate B obtained at 120°C for 1 hour. The lower limit of the 180° peel force of the adhesive layer (Y2) relative to the SUS304 board (hereinafter also referred to as "the 180° peel force of the heated adhesive layer (Y2) relative to SUS at 23°C") measured in accordance with JIS Z 0237 at 23°C and a peeling speed of 30 mm / min is 40 N / 25 mm. Because the 180° peel force of the heated adhesive layer (Y2) relative to SUS at 23°C is 40 N / 25 mm or more, the adhesive tape of the present invention exhibits excellent adhesive strength upon heating, resulting in superior reliability when bonding fluororesin to cans, etc. The preferred lower limit of the 180° peel force of the adhesive layer (Y2) after heating, relative to SUS at 23°C, is 45 N / 25 mm, and the more preferred lower limit is 50 N / 25 mm. Furthermore, there is no particular preferred upper limit for the 180° peel force of the adhesive layer (Y2) after heating on SUS at 23°C, but the practical upper limit is 100 N / 25 mm. The 180° peel force of the adhesive layer (Y2) after heating, relative to SUS at 23°C, may be 40N / 25mm to 100N / 25mm, 45N / 25mm to 100N / 25mm, or 50N / 25mm to 100N / 25mm.

[0021] The adhesive tape of the present invention is obtained by backing the adhesive layer (Y1) with a 1.0 mm thick polytetrafluoroethylene board, then bonding the adhesive layer (Y2) to a SUS304 board, and heating it at 120°C for 1 hour. For the laminate B obtained in accordance with JIS Z 0237, the preferred lower limit of the 180° peel force of the adhesive layer (Y2) relative to the SUS304 board (hereinafter also referred to as "the 180° peel force of the heated adhesive layer (Y2) relative to SUS at 80°C") is 20 N / 25 mm. Since the 180° peel force of the heated adhesive layer (Y2) relative to SUS at 80°C is 20 N / 25 mm or more, the resulting adhesive tape can exhibit superior adhesive strength upon heating, thus providing greater reliability when bonding fluororesin to cans, etc. A more preferable lower limit for the 180° peel force of the adhesive layer (Y2) after heating, relative to SUS at 80°C, is 25 N / 25 mm. Furthermore, there is no particular preferred upper limit for the 180° peel force of the adhesive layer (Y2) after heating relative to SUS at 80°C, but the practical upper limit is 50 N / 25 mm. The 180° peel force of the adhesive layer (Y2) after heating, relative to SUS at 80°C, may be 20N / 25mm to 50N / 25mm, or 25N / 25mm to 50N / 25mm.

[0022] The 180° peel force of the heated adhesive layer (Y2) against SUS at 23°C, and the 180° peel force of the heated adhesive layer (Y2) against SUS at 80°C, can be measured by the following method. Specifically, an adhesive tape with the above-mentioned adhesive layer (Y1) backed on a 1.0 mm thick polytetrafluoroethylene sheet (for example, "Yodoflon PTFE (F4) Film Sheet 4400" manufactured by Yodogawa Hutech Co., Ltd.) is cut to a size of 25 mm wide x 100 mm long. Then, the adhesive layer (Y2) side is placed on a thick SUS sheet (SUS304 sheet that has been washed with ethanol and then wiped dry), and laminate B is produced by pressing them together under pressure at 0.1 MPa for 1 hour in an environment of 120°C. For the obtained laminate B, 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 or 80°C, 50% RH, and a peeling speed of 30 mm / min. By peeling the adhesive tape from the SUS plate, the 180° peel force of the heated adhesive layer (Y2) relative to SUS at 23°C, or the 180° peel force of the heated adhesive layer (Y2) relative to SUS at 80°C, can be measured.

[0023] Methods for adjusting the 180° peel force of the heated adhesive layer (Y2) on SUS at 23°C and the 180° peel force of the heated adhesive layer (Y2) on SUS at 80°C 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), and changing the substrate.

[0024] The adhesive layer (Y1) is formed using an 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, and silicone resins. In particular, the base polymer (P1) preferably contains at least one selected from the group consisting of (meth)acrylic copolymers and styrene elastomers, as this allows for a wide range of designs for the adhesive layer (Y1) and enables the adhesive layer (Y1) to exhibit strong adhesive strength. Furthermore, from the viewpoint of suppressing contamination of the adherend, the base polymer (P1) is preferably a base polymer other than a silicone resin. 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.

[0025] The above (meth)acrylic copolymer preferably has constituent units derived from alkyl (meth)acrylate. The alkyl (meth)acrylate described above preferably includes an alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus. That is, the (meth)acrylic copolymer preferably has structural units derived from an alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus. By having structural units derived from an alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus, the glass transition temperature (Tg) of the (meth)acrylic copolymer is further reduced. As a result, the flexibility of the adhesive layer (Y1) is further improved, and the adhesion strength of the adhesive layer (Y1) to the fluororesin is further improved. 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.

[0026] 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 resulting adhesive tape has superior adhesion (especially to fluororesins), 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.

[0027] 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, and the adhesion strength of the adhesive layer (Y1) to the fluororesin is further improved. 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 85% by mass, an even more preferred lower limit is 90% by mass, and an even more preferred lower limit is 95% by mass. Furthermore, from the viewpoint of 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 the ester terminus is 99.5% by mass, and the more preferred upper limit is 99% by mass. The content of the constituent units derived from alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms at its ester terminus may be 50% to 99.5% by mass, 85% to 99% by mass, 90% to 99% by mass, or 95% to 99% by mass.

[0028] 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 types.

[0029] The (meth)acrylic copolymer preferably further contains structural units derived from a polar functional group-containing monomer. The presence of structural units derived from a polar functional group-containing monomer in the (meth)acrylic copolymer increases the bulk cohesive strength of the adhesive layer (Y1), resulting in a more adhesive tape.

[0030] The above polar functional group is reactive, such as through crosslinking reactions, and preferably at least one selected from the group consisting of carboxyl groups, hydroxyl groups, amino groups, and epoxy groups. In particular, one selected from the group consisting of carboxyl groups and hydroxyl groups is more preferred because it can contribute to improving the adhesive strength of the resulting adhesive tape. That is, it is preferable that the (meth)acrylic copolymer has at least one structural unit selected from the group consisting of a structural unit derived from a polar functional group-containing monomer (carboxyl group-containing monomer) having a carboxyl group as the above polar functional group, and a structural unit derived from a polar functional group-containing monomer (hydroxyl group-containing monomer) having a hydroxyl group as the above polar functional group. Examples of the above-mentioned carboxyl group-containing monomers include (meth)acrylic acid. Examples of the hydroxyl group-containing monomers mentioned above include 4-hydroxybutyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate. Examples of polar functional group-containing monomers (epoxy group-containing monomers) having an epoxy group as the polar functional group include glycidyl (meth)acrylate. The above-mentioned monomers containing polar functional groups may be used individually or in combination of two or more types.

[0031] 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 3.0% by mass. By having the content of constituent units derived from the carboxyl group-containing monomer within this range, the cohesive force of the bulk of the adhesive layer (Y1) can be appropriately adjusted, resulting in an adhesive tape with superior adhesion. 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 2.0% by mass. The content of the constituent units derived from the above-mentioned carboxyl group-containing monomer may be 0.01% by mass to 3.0% by mass, or 0.05% by mass to 2.0% by mass.

[0032] 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 3.0% by mass. By having the content of constituent units derived from the above hydroxyl group-containing monomer within this range, the cohesive force of the bulk of the adhesive layer (Y1) can be appropriately adjusted, resulting in an adhesive tape with superior adhesion. 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 2.0% by mass. The content of the constituent units derived from the above-mentioned hydroxyl group-containing monomer may be 0.01% by mass to 3.0% by mass, or 0.05% by mass to 2.0% by mass.

[0033] 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. By having the total content of constituent units derived from the above polar functional group-containing monomer within this range, the cohesive force of the bulk of the adhesive layer (Y1) can be appropriately adjusted, resulting in an adhesive tape with superior adhesion. 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. The total content of constituent units derived from the above polar functional group-containing monomer may be 0.01% by mass to 6.0% by mass, or 0.1% by mass to 3.0% by mass.

[0034] 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.

[0035] 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 improves the bulk cohesive force of the adhesive layer (Y1), resulting in a more adhesive tape. A weight-average molecular weight (Mw) of 1,600,000 or less further improves the adhesion of the adhesive layer (Y1) to the fluororesin. 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. The weight-average molecular weight (Mw) of the above (meth)acrylic copolymer may be between 50,000 and 1,600,000, or between 100,000 and 1,200,000.

[0036] The preferred lower limit for the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the (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 (meth)acrylic copolymer is 1.05 or higher, the adhesive layer (Y1) becomes more flexible, and the resulting adhesive tape has better adhesion to fluororesin. When the molecular weight distribution (Mw / Mn) of the (meth)acrylic copolymer is 10.0 or lower, the proportion of low molecular weight components is suppressed, the bulk cohesive force of the adhesive layer (Y1) is improved, and the resulting adhesive tape has better adhesion. A more preferred upper limit for the molecular weight distribution (Mw / Mn) of the (meth)acrylic copolymer is 9.0, an even more preferred upper limit is 8.0, and an even more preferred upper limit is 7.0. The molecular weight distribution (Mw / Mn) of the above (meth)acrylic copolymer may be 1.05 to 10.0, 1.05 to 9.0, 1.05 to 8.0, or 1.05 to 7.0.

[0037] 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).

[0038] 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.

[0039] The preferred lower limit for 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 resulting adhesive tape exhibiting superior adhesion to fluororesin. A more preferred lower limit for the glass transition temperature (Tg) of the above (meth)acrylic copolymer is -60°C, and a more preferred upper limit is -40°C. The glass transition temperature (Tg) of the above (meth)acrylic copolymer may be -70°C to -30°C or -60°C to -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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] Examples of the styrene-based elastomers mentioned above include styrene-isoprene-styrene (SIS) block copolymer, styrene-butadiene-styrene (SBS) block copolymer, styrene-chloroprene-styrene 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 tape 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.

[0047] 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 higher, the adhesive strength of the adhesive layer (Y1) to the adherend is further improved, and the resulting adhesive tape has superior adhesive properties. In addition, the flexibility of the adhesive layer (Y1) is further improved, so the adhesive strength of the adhesive layer (Y1) to the fluororesin is further improved. 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 Zibloc ratio may be 50% to 90% by mass, or 70% to 90% by mass. The above diblock ratio can be calculated from the peak area ratio of each copolymer measured by gel permeation chromatography (GPC).

[0048] 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. When the styrene content is 20% by mass or less, the adhesive layer (Y1) does not become too hard, the adhesive strength to the adherend is further improved, and the resulting adhesive tape has superior adhesion. 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 styrene content may be 8% to 20% by mass, or 8% to 16% by mass. The above styrene content is, 1 It can be calculated from the peak area ratio of each block measured by 1H-NMR.

[0049] The preferred lower limit for the weight-average molecular weight (Mw) of the above styrene-based elastomer is 50,000, and the preferred upper limit is 600,000. A weight-average molecular weight (Mw) of 50,000 or more for the above styrene-based elastomer increases the bulk strength of the adhesive layer (Y1), resulting in a more adhesive tape with superior adhesion. A weight-average molecular weight (Mw) 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 (Mw) of the above styrene-based elastomer is 100,000, and a more preferred upper limit is 500,000. The weight-average molecular weight (Mw) of the above styrene-based elastomer may be between 50,000 and 600,000, or between 100,000 and 500,000.

[0050] Examples of commercially available silicone resins include KR-3700 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0051] 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. Having the base polymer (P1) content within this range further improves the adhesion of the adhesive layer (Y1) to the fluororesin. 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. The content of the above base polymer (P1) may be 30% to 99.5% by mass, 40% to 99% by mass, or 50% to 95% by mass.

[0052] The above adhesive composition (X1) preferably contains a tackifying resin (T1). The tackifying resin (T1) preferably contains a tackifying resin (T1-1) having at least one constituent unit (A) selected from the group consisting of constituent units (A-1), (A-1'), (A-2), (A-2'), (A-3), (A-3'), (A-4), and (A-4') represented by the above formula. By including the tackifying resin (T1-1) in the adhesive composition (X1), the adhesive layer (Y1) can exhibit higher adhesive strength, particularly to adherends with low polarity (e.g., fluororesins). In particular, the interaction with the adherend can be greatly improved, and the adhesive strength to the adherend can be further enhanced, so it is preferable that the above-mentioned structural unit (A) is at least one selected from the group consisting of structural unit (A-1), structural unit (A-1'), structural unit (A-2), structural unit (A-2'), structural unit (A-3), and structural unit (A-3'), and it is more preferable that it is at least one selected from the group consisting of structural unit (A-1) and structural unit (A-1'). By the above-mentioned structural unit (A) being at least one selected from the group consisting of structural unit (A-1) and structural unit (A-1'), the interaction with the adherend can be further greatly improved. Furthermore, since monomers containing bio-derived materials, which will be described later, can be easily used as monomers constituting the above-mentioned structural unit (A-1) and structural unit (A-1'), it is preferable from the viewpoint of saving petroleum resources. Furthermore, if the base polymer (P1) contains the (meth)acrylic copolymer, the tackifying resin (T1-1) has appropriate polarity, which further improves its compatibility with the (meth)acrylic copolymer.

[0053] The tackifying resin (T1-1) may have the above-mentioned structural unit (A) in the side chain, or in the main chain skeleton or at the ends of the main chain skeleton. In particular, it is preferable that the tackifying resin (T1-1) has the above-mentioned structural unit (A) in the main chain skeleton or at the ends of the main chain skeleton, as this allows it to have suitable physical properties required as a tackifying resin.

[0054] In the above structural unit (A), R 1 ~R 7 each represents a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a group having a polar functional group. Examples of the aliphatic hydrocarbon group include linear, branched, or cyclic alkyl groups having 1 to 20 carbon atoms. Examples of the aromatic hydrocarbon group include substituted or unsubstituted aryl groups having 1 to 20 carbon atoms. Specific examples of the polar functional group in the group having a polar functional group include monovalent functional groups having a carbonyl group, an amino group, an alkoxy group having 1 to 2 carbon atoms, a hydroxyl group, a nitrile group, a nitro group, and the like. Examples of the monovalent functional group containing a carbonyl group include a carboxy group, a group containing an ester bond, an aldehyde group, an enone group, a group containing an amide bond, a group containing a thioester bond, and the like. Incidentally, R 1 can use, as the group having a polar functional group, other than a hydroxyl group, and R 2 can use, as the group having a polar functional group, other than a carboxy group, and R 3 can use, as the group having a polar functional group, other than a group represented by OR 4 and R 5 can use, as the group having a polar functional group, other than a group represented by NR 6 R 7 and can use, as the group having a polar functional group, other than a group represented by. The group having a polar functional group may be the polar functional group itself, an aliphatic hydrocarbon group having the polar functional group, or an aromatic hydrocarbon group having the polar functional group. Examples of the aliphatic hydrocarbon group having a polar functional group include groups in which one or more hydrogens in the aliphatic hydrocarbon group are substituted with the polar functional group. Examples of the aromatic hydrocarbon group having a polar functional group include groups in which one or more hydrogens in the aromatic hydrocarbon group are substituted with the polar functional group.

[0055] Furthermore, in the above-mentioned tackifying resin (T1-1), multiple R components are included in one constituent unit (A-1). 1 These may be the same or different. Also, multiple Rs contained in different constituent units (A-1) 1 These may be the same or different. Similarly, multiple Rs contained within a single constituent unit (A-1') 1 These may be the same or different. Also, multiple Rs contained in different constituent units (A-1') 1 They may be the same or they may be different.

[0056] Similarly, multiple R units contained within a single constituent unit (A-2) 2 These may be the same or different. Also, multiple Rs contained in different constituent units (A-2) 2 These may be the same or different. Similarly, multiple Rs contained within a single constituent unit (A-2') 2 These may be the same or different. Also, multiple Rs contained in different constituent units (A-2') 2 They may be the same or they may be different.

[0057] Similarly, multiple Rs contained within a single constituent unit (A-3) 3 These may be the same or different. Also, multiple Rs contained in different constituent units (A-3) 3 These may be the same or different. Similarly, multiple Rs contained within a single constituent unit (A-3') 3 These may be the same or different. Also, multiple Rs contained in different constituent units (A-3') 3 They may be the same or they may be different.

[0058] Similarly, multiple Rs contained within one constituent unit (A-3) 4These may be the same or different. Also, multiple Rs contained in different constituent units (A-3) 4 These may be the same or different. Similarly, multiple Rs contained within a single constituent unit (A-3') 4 These may be the same or different. Also, multiple Rs contained in different constituent units (A-3') 4 They may be the same or they may be different.

[0059] Similarly, multiple Rs contained within a single constituent unit (A-4) 5 These may be the same or different. Also, multiple Rs contained in different constituent units (A-4) 5 These may be the same or different. Similarly, multiple Rs contained within a single constituent unit (A-4') 5 These may be the same or different. Also, multiple Rs contained in different constituent units (A-4') 5 They may be the same or they may be different.

[0060] Similarly, multiple Rs contained within a single constituent unit (A-4) 6 and R 7 These may be the same or different. Also, multiple Rs contained in different constituent units (A-4) 6 and R 7 These may be the same or different. Similarly, multiple Rs contained within a single constituent unit (A-4') 6 and R 7 These may be the same or different. Also, multiple Rs contained in different constituent units (A-4') 6 and R 7 They may be the same or they may be different.

[0061] In the above-mentioned structural unit (A), n and l are integers between 2 and 4, and n' and l' are integers between 2 and 5, but from the viewpoint of ease of obtaining raw materials, it is preferable that n, l, n', and l' are 2 or 3, and it is more preferable that n, l, n', and l' are 3, as this can further improve the adhesive strength of the adhesive layer (Y1).

[0062] In the above-mentioned structural unit (A), m and k are integers between 1 and 4, and m' and k' are integers between 1 and 5, but from the viewpoint of ease of obtaining raw materials, it is preferable that m, k, m', and k' are 1, 2, or 3, and it is more preferable that m, k, m', and k' are 1, as this can further improve the adhesive strength of the adhesive layer (Y1).

[0063] More specifically, the above-mentioned constituent units (A-1) and (A-1') include, for example, a constituent unit derived from dihydroxybenzene or its derivatives (when n and n' are 2), a constituent unit derived from trihydroxybenzene or its derivatives (when n and n' are 3), and so on. These constituent units may be used individually, or two or more may be used in combination.

[0064] Examples of the above-mentioned dihydroxybenzene or its derivatives include resorcinol, pyrocatechol, hydroquinone, dihydroxytoluene, dihydroxyxylene, dihydroxyphenylethylamine hydrochloride, dihydroxybenzoic acid, dihydroxyphenylacetic acid, dihydroxyhydrocinnamic acid, dihydroxyphenylpropionic acid, dihydroxyphenylalanine, dihydroxybenzaldehyde, dihydroxyacetophenone, diacetyldihydroxybenzene, dihydroxyphenyl-2-butanone, dihydroxyphenylmethyl acetate, benzyldihydroxyphenyl ketone, dihydroxybenzamide, dihydroxymethoxybenzene, dihydroxybenzyl alcohol, dihydroxyphenylethanol, dihydroxyphenyl glycol, dihydroxyphenylacetonitrile, and dihydroxynitrobenzene. Among these, pyrocatechol is preferred because it has low steric hindrance and readily interacts with the adherend. The above-mentioned dihydroxybenzene or its derivatives may be used alone or in combination of two or more types.

[0065] Examples of the above-mentioned trihydroxybenzene or its derivatives include pyrogallol, 1,2,4-trihydroxybenzene, phloroglucinol, trihydroxytoluene, trihydroxydiphenylmethane, 6-hydroxy-L-dopa, gallic acid, methyl gallate, butyl gallate, isobutyl gallate, isoamyl gallate, hexadecyl gallate, stearyl gallate, trihydroxyacetophenone, trihydroxyphenylethanone, trihydroxyphenylbutanone, trihydroxybenzaldehyde, trihydroxybenzamide, and trihydroxynitrobenzene. Among these, pyrogallol is preferred because it has low steric hindrance and readily interacts with the adherend. The above-mentioned trihydroxybenzene or its derivatives may be used alone or in combination of two or more types.

[0066] More specifically, the above-mentioned constituent units (A-2) and (A-2') include constituent units derived from benzoic acid, salicylic acid, dihydroxybenzoic acid, gallic acid, 2-methylbenzoic acid, 3-methylbenzoic acid, 4-methylbenzoic acid, 2-ethylbenzoic acid, 3-ethylbenzoic acid, 4-ethylbenzoic acid, 4-tert-butylbenzoic acid, 2-vinylbenzoic acid, 3-vinylbenzoic acid, 4-vinylbenzoic acid, 4,4'-stilbendicarboxylic acid, and their derivatives. Among these, the constituent unit derived from 4-vinylbenzoic acid is preferred because it has less steric hindrance and readily interacts with the adherend. These constituent units may be used individually, or two or more may be used in combination.

[0067] More specifically, the above-mentioned constituent units (A-3) and (A-3') include, for example, constituent units derived from dialkoxybenzene or its derivatives (when l and l' are 2), and constituent units derived from trialkoxybenzene or its derivatives (when l and l' are 3).

[0068] Examples of the above-mentioned dialkoxybenzene or its derivatives include 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, and 1,4-dimethoxybenzene. The above-mentioned dialkoxybenzene or its derivatives may be used alone or in combination of two or more types.

[0069] Examples of trialkoxybenzene or its derivatives include 1,2,3-trimethoxybenzene, 1,2,4-trimethoxybenzene, and 1,3,5-trimethoxybenzene. Among these, 1,2,3-trimethoxybenzene is preferred because it has low steric hindrance and readily interacts with the adherend. The above trialkoxybenzene or its derivatives may be used alone or in combination of two or more types.

[0070] More specifically, the above-mentioned constituent units (A-4) and (A-4') include, for example, constituent units derived from aminobenzene or its derivatives (when k and k' are 1). Examples of the above-mentioned aminobenzene or its derivatives include aniline, methylaniline, ethylaniline, dimethylaniline, and diethylaniline. The above-mentioned aminobenzene or its derivatives may be used alone or in combination of two or more types.

[0071] The above-mentioned component (A) may consist solely of petroleum-derived materials, but it is preferable that it includes bio-derived materials. The depletion of petroleum resources and the emission of carbon dioxide from the combustion of petroleum-derived products are serious concerns. Therefore, attempts are being made to conserve petroleum resources by using bio-derived materials instead of petroleum-derived materials. It is preferable from the standpoint of conserving petroleum resources if the above-mentioned component (A) includes bio-derived materials. Furthermore, if the above-mentioned component (A) includes bio-derived materials, since bio-derived materials are originally produced by absorbing carbon dioxide from the atmosphere, it is thought that burning them will not increase the total amount of carbon dioxide in the atmosphere, which is also preferable from the standpoint of reducing carbon dioxide emissions. Examples of monomers constituting the above-mentioned constituent unit (A), which includes bio-derived materials, include resorcinol, dihydroxyphenylethylamine hydrochloride, dihydroxyhydrocinnamic acid, dihydroxyphenylalanine, dihydroxybenzaldehyde, dihydroxybenzyl alcohol, pyrogallol, 1,2,4-trihydroxybenzene, phloroglucinol, 6-hydroxy-L-dopa, gallic acid, methyl gallate, butyl gallate, isobutyl gallate, isoamyl gallate, hexadecyl gallate, stearyl gallate, trihydroxyacetophenone, trihydroxybenzaldehyde, trihydroxybenzamide, trihydroxynitrobenzene, and the like.

[0072] The preferred lower limit for the content (molar basis) of the constituent unit (A) in the tackifying resin (T1-1) is 1 mol%, and the preferred upper limit is 60 mol%. By having a content (molar basis) of 1 mol% or more of the constituent unit (A), the adhesive strength of the adhesive layer (Y1) can be further improved by blending the tackifying resin (T1-1) into the adhesive composition (X1). By having a content (molar basis) of 60 mol% or less of the constituent unit (A), the tackifying resin (T1-1) will have the preferred physical properties required for a tackifying resin. A more preferred lower limit for the content (molar basis) of the constituent unit (A) is 5 mol%, a more preferred upper limit is 50 mol%, an even more preferred lower limit is 10 mol%, and an even more preferred upper limit is 30 mol%. The content ratio (on a mole basis) of the above constituent unit (A) may be 1 mol% to 60 mol%, 5 mol% to 50 mol%, or 10 mol% to 30 mol%. Furthermore, the preferred lower limit of the content ratio (by mass) of the constituent unit (A) in the tackifying resin (T1-1) is 0.9% by mass, and the preferred upper limit is 60% by mass. By having a content ratio (by mass) of 0.9% by mass or more of the constituent unit (A), the adhesive strength of the adhesive layer (Y1) can be further improved by blending the tackifying resin (T1-1) into the adhesive composition (X1). By having a content ratio (by mass) of 60% by mass or less of the constituent unit (A), the tackifying resin (T1-1) will have the preferred physical properties required for a tackifying resin. A more preferred lower limit of the content ratio (by mass) of the constituent unit (A) is 5% by mass, a more preferred upper limit is 50% by mass, an even more preferred lower limit is 10% by mass, and an even more preferred upper limit is 30% by mass. The content ratio (by mass) of the above constituent unit (A) may be 0.9% to 60% by mass, 5% to 50% by mass, or 10% to 30% by mass.

[0073] Preferably, the tackifying resin (T1-1) further has a constituent unit (B) derived from at least one monomer (b) selected from the group consisting of terpene monomers and vinyl monomers. By having the above constituent unit (B) in the tackifying resin (T1-1), the adhesive strength of the adhesive layer (Y1) can be further improved. Furthermore, from the viewpoint of improving compatibility with the base polymer, the tackifying resin (T1-1) is preferably composed of structural units derived from terpene monomers. Since the structural units derived from terpene monomers have an aliphatic hydrocarbon group having an unsaturated double bond, the tackifying resin (T1-1) having structural units derived from terpene monomers improves the compatibility between the tackifying resin (T1-1) and the base polymer (P1), thereby suppressing a decrease in the adhesive strength of the adhesive layer (Y1) due to deterioration of compatibility.

[0074] Examples of the above-mentioned terpene monomers include α-pinene, β-pinene, limonene, dipentene, δ-3-carene, dimethyloctatriene, allocimene, myrcene, ocimene, linalool, and cosmene. Among these, α-pinene, β-pinene, or limonene are preferred because they can further improve the adhesive strength of the adhesive layer (Y1). As the vinyl monomers mentioned above, vinyl monomers that do not have a structure containing two or more aromatic rings in one molecule (for example, naphthalene structure, anthracene structure, biphenyl structure, anthraquinone structure, benzophenone structure, etc.) are preferred from the viewpoint of improving the compatibility between the tackifying resin (T1-1) and the base polymer (P1). Examples of vinyl monomers that do not have a structure containing two or more aromatic rings in a single molecule include ethylene, propylene, butylene, hexene, vinyl acetate, vinyl chloride, styrene, α-methylstyrene, coumarone, indene, vinyltoluene, divinylbenzene, divinyltoluene, and 2-phenyl-2-butene. Among these, styrene is preferred because it can further improve the adhesive strength of the adhesive layer (Y1). The above monomer (b) may be used alone or in combination of two or more types.

[0075] The above-mentioned component unit (B) may consist solely of petroleum-derived materials, but it is preferable that it includes bio-derived materials. The depletion of petroleum resources and the emission of carbon dioxide from the combustion of petroleum-derived products are serious concerns. Therefore, attempts are being made to conserve petroleum resources by using bio-derived materials instead of petroleum-derived materials. It is preferable from the standpoint of conserving petroleum resources if the above-mentioned component unit (B) includes bio-derived materials. Furthermore, if the above-mentioned component unit (B) includes bio-derived materials, since bio-derived materials are originally produced by absorbing carbon dioxide from the atmosphere, it is thought that burning them will not increase the total amount of carbon dioxide in the atmosphere, which is also preferable from the standpoint of reducing carbon dioxide emissions. Examples of monomers (b) that constitute the above-mentioned constituent unit (B) containing bio-derived materials include terpene monomers, ethylene, propylene, hexene, and the like.

[0076] The preferred lower limit for the content of the constituent unit (B) in the tackifying resin (T1-1) is 40 mol%, and the preferred upper limit is 99 mol%. By having a content of 40 mol% or more of the constituent unit (B), the tackifying resin (T1-1) can have the desirable physical properties required for a tackifying resin. By having a content of 99 mol% or less of the constituent unit (B), the content of the constituent unit (A) can be sufficiently secured, thereby further improving the adhesive strength of the adhesive layer (Y1), and in particular, further improving the adhesive strength even to adherends with low polarity. The more preferred lower limit for the content of the constituent unit (B) is 50 mol%, and the more preferred upper limit is 90 mol%. The content of the above constituent unit (B) may be 40 mol% to 99 mol%, or 50 mol% to 90 mol%.

[0077] The tackifying resin (T1-1) is preferably a copolymer having a structure represented by the following formula. In particular, when the above constituent unit (A) is present in or at the end of the main chain skeleton, it is preferable that the copolymer has a structure represented by the following formula. Copolymers having such a structure are obtained by a cationic polymerization method as described later, and can further improve the adhesive strength of the adhesive layer (Y1), and in particular can further improve the adhesive strength even to adherends with low polarity.

[0078] [ka]

[0079] In the formula, A represents a constituent unit (A), B represents a constituent unit (B), and s and t each represent an integer greater than or equal to 1. * represents a connection.

[0080] The tackifying resin (T1-1) is preferably a copolymer having the above-mentioned structural unit (A) and the above-mentioned structural unit (B), and may further have other structural units. When the tackifying resin (T1-1) is a copolymer having the above-mentioned structural unit (A) and the above-mentioned structural unit (B), the above-mentioned structural unit (A) and the above-mentioned structural unit (B) may be copolymerized randomly, or they may be copolymerized in a regular or periodic manner, for example, when each forms a block segment and the block segments are bonded to each other.

[0081] The tackifying resin (T1-1) described above preferably has an aliphatic hydrocarbon group having an unsaturated double bond. The tackifying resin (T1-1) may have the aliphatic hydrocarbon group having an unsaturated double bond in the constituent unit (A) or the constituent unit (B), or in other constituent units. In particular, from the viewpoint of ease of synthesis and improving the compatibility between the tackifying resin (T1-1) and the base polymer (P1), and especially between the tackifying resin (T1-1) and the styrene elastomer, it is preferable that the aliphatic hydrocarbon group having an unsaturated double bond is present in the constituent unit (B) or other constituent units. The constituent unit (B) or other constituent units having such aliphatic hydrocarbon group having an unsaturated double bond are not particularly limited, but it is preferable that the constituent unit (B) is derived from at least one monomer (b) selected from the group consisting of terpene monomers and vinyl monomers. In other words, it is preferable that the tackifying resin (T1-1) has the aliphatic hydrocarbon group having an unsaturated double bond in a constituent unit (B) derived from at least one monomer (b) selected from the group consisting of terpene monomers and vinyl monomers. In particular, it is preferable that the aliphatic hydrocarbon group having an unsaturated double bond is contained in a constituent unit derived from a terpene monomer, as this can further improve the adhesive strength of the adhesive layer (Y1).

[0082] Other constituent units mentioned above include, for example, constituent units derived from other phenolic monomers not included in constituent unit (A), and constituent units derived from maleic anhydride. Other phenolic monomers mentioned above include, for example, phenol, cresol, xylenol, propylphenol, norylphenol, methoxyphenol, bromophenol, bisphenol A, bisphenol F, bisphenol S, and dihydroxynaphthalene. The other phenolic monomers mentioned above may be used individually or in combination of two or more.

[0083] The preferred lower limit of the weight-average molecular weight (Mw) of the above tackifying resin (T1-1) is 400, and the preferred upper limit is 10,000. When the weight-average molecular weight (Mw) of the above tackifying resin (T1-1) is within this range, the above tackifying resin (T1-1) will have the preferred physical properties required for a tackifying resin. A more preferred lower limit of the weight-average molecular weight (Mw) of the above tackifying resin (T1-1) is 500, a more preferred upper limit is 5000, an even more preferred lower limit is 700, and an even more preferred upper limit is 3000. The weight-average molecular weight (Mw) of the above-mentioned tackifying resin (T1-1) may be 400 to 10,000, 500 to 5,000, or 700 to 3,000. Methods for adjusting the weight-average molecular weight (Mw) to the above range include, for example, adjusting the composition, polymerization method, and polymerization conditions of the tackifying resin (T1-1).

[0084] The preferred lower limit of the Young's modulus of the tackifying resin (T1-1) at 25°C is 10 MPa. A Young's modulus of 10 MPa or higher at 25°C for the tackifying resin (T1-1) provides appropriate hardness and desirable physical properties required for a tackifying resin. A more preferred lower limit for the Young's modulus of the tackifying resin (T1-1) at 25°C is 50 MPa, and an even more preferred lower limit is 70 MPa. Furthermore, from the viewpoint of preventing the adhesive layer (Y1) from becoming too hard and reducing its adhesive strength, the preferred upper limit for the Young's modulus of the tackifying resin (T1-1) at 25°C is 10,000 MPa, and the more preferred upper limit is 5,000 MPa. The Young's modulus of the above-mentioned tackifying resin (T1-1) at 25°C may be 10 MPa to 10,000 MPa, 50 MPa to 5,000 MPa, or 70 MPa to 5,000 MPa. The Young's modulus of the tackifying resin (T1-1) at 25°C can be measured by performing a tensile test using a tensile testing machine (e.g., ORIENTEC's "Tensilon") under the conditions of a tensile speed of 200 mm / min, a grip distance of 15 mm, and a temperature of 25°C. A sample for this measurement can be obtained, for example, by filling a mold measuring 10 × 50 mm with the tackifying resin (T1-1) and melting it at a temperature 100°C higher than the glass transition temperature to produce a test piece with a thickness of 1 mm.

[0085] Methods for adjusting the Young's modulus of the tackifying resin (T1-1) at 25°C to within the above range include, for example, adjusting the molecular weight or weight-average molecular weight of the tackifying resin (T1-1), the composition and content ratio of the constituent units (A) and (B) in the tackifying resin (T1-1), etc.

[0086] The preferred lower limit for the glass transition temperature (Tg) of the above tackifying resin (T1-1) is 0°C, and the preferred upper limit is 200°C. Having the glass transition temperature (Tg) of the above tackifying resin (T1-1) within this range makes it easier to adjust the Young's modulus of the above tackifying resin (T1-1) at 25°C to within this range, thus allowing the above tackifying resin (T1-1) to possess the desirable physical properties required for a tackifying resin. A more preferred lower limit for the glass transition temperature (Tg) of the above tackifying resin (T1-1) is 10°C, and a more preferred upper limit is 150°C. The glass transition temperature (Tg) of the tackifying resin (T1-1) described above may be 0°C to 200°C or 10°C to 150°C.

[0087] The preferred lower limit of the iodine value of the tackifying resin (T1-1) is 2 g / 100 g, and the preferred upper limit is 180 g / 100 g. Having an iodine value of 2 g / 100 g or higher makes it easier to suppress the decrease in adhesive strength of the adhesive layer (Y1) caused by poor compatibility between the tackifying resin (T1-1) and the base polymer (P1). Having an iodine value of 180 g / 100 g or lower further improves the adhesive strength of the adhesive layer (Y1), and in particular, it can further improve adhesive strength even to low-polarity substrates. A more preferred lower limit of the iodine value of the tackifying resin (T1-1) is 70 g / 100 g, and a more preferred upper limit is 170 g / 100 g. The iodine value of the above tackifying resin (T1-1) may be 2g / 100g to 180g / 100g, or 70g / 100g to 170g / 100g. The iodine value is an indicator of the amount of unsaturated double bonds (C=C bond amount), and refers to the value measured in accordance with the method described in "JIS K 0070:1992".

[0088] The preferred lower limit for the content of bio-derived carbon (carbon atoms) in the carbon (carbon atoms) of the above-mentioned tackifying resin (T1-1) is 10%. A bio-derived carbon content of 10% or more is an indicator that a product is "bio-based". The above tackifying resin (T1-1) is preferable if it contains 10% or more bio-derived carbon, from the viewpoint of conserving petroleum resources and reducing carbon dioxide emissions. A more preferable lower limit for the bio-derived carbon content of the above tackifying resin (T1-1) is 30%, an even more preferable lower limit is 60%, an even more preferable lower limit is 70%, and a particularly preferable lower limit is 90%. There is no particular preferred upper limit for the bio-derived carbon content of the above tackifying resin (T1-1), and it may be 100%. The bio-derived carbon content of the above tackifying resin (T1-1) may be 10% to 100%, 30% to 100%, 60% to 100%, 70% to 100%, or 90% to 100%. Furthermore, while bio-derived carbon contains a certain percentage of the radioactive isotope (C-14), petroleum-derived carbon contains almost no C-14. Therefore, the percentage of bio-derived carbon in the above-mentioned tackifying resin (T1-1) can be calculated by measuring the concentration of C-14 contained in the compound. Specifically, this can be measured in accordance with ASTM D6866-22, a standard widely used in the bioplastics industry.

[0089] The tackifying resin (T1-1) described above also includes hydrogenated compounds of the compounds described above. A hydrogenated compound is a compound in which at least partially the carbon-carbon double bonds present in the tackifying resin (T1-1) described above have been saturated by hydrogenation. That is, the adhesive composition (X1) may contain a hydrogenated compound in which some of the carbon-carbon double bonds in the tackifying resin (T1-1) have been hydrogenated, or it may contain a hydrogenated compound in which all of the carbon-carbon double bonds in the tackifying resin (T1-1) have been hydrogenated. Even such a hydrogenated compound can be suitably used as a tackifying resin to be blended into the adhesive composition (X1), and can improve the adhesive strength of the adhesive layer (Y1), and in particular can improve the adhesive strength even to adherends with low polarity.

[0090] The method for producing the above-mentioned tackifying resin (T1-1) is not particularly limited, but when the above-mentioned constituent unit (A) is present in or at the end of the main chain skeleton, the following method is preferred, for example. In other words, a method of copolymerizing monomer (a) constituting the above-mentioned structural unit (A) with at least one monomer (b) selected from the group consisting of terpene monomers and vinyl monomers constituting the above-mentioned structural unit (B) (hereinafter also referred to as "production method [I]") is preferred.

[0091] The monomer (a) is preferably at least one selected from the group consisting of monomer (a-1), monomer (a-2), monomer (a-3), and monomer (a-4), which are represented by the following formula.

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] In formulas (a-1) to (a-4), R 1 ~R 7 Each of the following represents a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a polar functional group, an aliphatic hydrocarbon group having a polar functional group, or an aromatic hydrocarbon group having a polar functional group. n'' represents an integer between 2 and 5, preferably 2 or 3, and more preferably 3. m'' represents an integer between 1 and 5. l'' represents an integer between 2 and 5. k'' represents an integer between 1 and 5.

[0097] In the method for producing the tackifying resin (T1-1) described above [I], it is preferable to copolymerize monomer (a) and monomer (b) by cationic polymerization. By using the cationic polymerization described above, monomer (a) and monomer (b) can be copolymerized without prior chemical modification to protect the functional groups of monomer (a), such as phenolic hydroxyl groups, carboxyl groups, alkoxy groups, and amino groups, and subsequent deprotection is also unnecessary. Therefore, monomer (a) and monomer (b) can be copolymerized in a simpler one-step reaction process, leading to a reduction in impurities and an improvement in yield.

[0098] A preferred method for copolymerizing monomer (a) and monomer (b) by cationic polymerization is to react monomer (a) and monomer (b) in the presence of a Lewis acid. This method is thought to generate cations of monomer (b), leading to cationic polymerization between monomers (b) and a Fridel-Crafts alkylation reaction between monomer (a) and monomer (b). Repeated reactions of this nature allow for the production of a copolymer having constituent units (A) derived from monomer (a) and constituent units (B) derived from monomer (b). The Lewis acid mentioned above is not particularly limited, and conventionally known Lewis acids can be used, such as aluminum chloride (AlCl3), diethylaluminum chloride (Et2AlCl2), tin(IV) chloride (SnCl4), titanium(IV) chloride (TiCl4), boron trichloride (BCl3), and boron trifluoride ether complex (BF3·EtO). Among these, aluminum chloride (AlCl3) is preferred because it yields a higher yield of copolymer.

[0099] More specifically, for example, if pyrogallol is used as monomer (a) and α-pinene is used as monomer (b), and these are reacted in the presence of aluminum chloride (AlCl3), which is a Lewis acid, the reaction shown in the following scheme is expected to proceed. Specifically, a cation of monomer (b), α-pinene, is generated, and cationic polymerization of α-pinenes proceeds (upper part of the scheme below), while a Fridel-Crafts alkylation reaction proceeds between monomer (a), pyrogallol, and monomer (b), α-pinene (middle part of the scheme below). By repeatedly performing such reactions, a copolymer having structural units derived from pyrogallol and structural units derived from α-pinene can be obtained (lower part of the scheme below). Such a copolymer will have structural units derived from pyrogallol in the main chain skeleton or at the ends of the main chain skeleton.

[0100] [ka]

[0101] In the expression, s and t each represent an integer greater than or equal to 1. * represents a concatenation.

[0102] As for the method of producing the above-mentioned tackifying resin (T1-1), if the above-mentioned structural unit (A) is present in the side chain, for example, the following method is preferred. In other words, a method of copolymerizing a monomer (a') obtained by introducing an unsaturated double bond to monomer (a) constituting the above-mentioned structural unit (A), with at least one monomer (b) selected from the group consisting of terpene monomers and vinyl monomers constituting the above-mentioned structural unit (B) (hereinafter also referred to as "production method [II]") is preferred.

[0103] Examples of the above monomer (a') include 2-vinylbenzoic acid, 3-vinylbenzoic acid, 4-vinylbenzoic acid, and 4,4'-stilbendicarboxylic acid. Among these, 4-vinylbenzoic acid is preferred because it has less steric hindrance and readily interacts with the adherend. The above monomer (a') may be used alone or in combination of two or more types.

[0104] In the above method for producing the tackifying resin (T1-1) [II], it is preferable to copolymerize the monomer (a') and the monomer (b) by cationic polymerization, similar to the method for producing the tackifying resin (T1-1) [I]. A preferred method for copolymerizing monomer (a') and monomer (b) by cationic polymerization is to react monomer (a') and monomer (b) in the presence of a Lewis acid as described above. By such a method, cationic polymerization proceeds between the unsaturated double bond in monomer (a') and the unsaturated double bond in monomer (b), and a copolymer having constituent units (A) derived from monomer (a') and constituent units (B) derived from monomer (b) can be obtained.

[0105] The above-mentioned tackifying resin (T1-1) can improve the adhesive strength of the adhesive layer (Y1) even in a small amount compared to conventional tackifying resins. The preferred lower limit of the content of the above-mentioned tackifying resin (T1-1) per 100 parts by mass of the above-mentioned base polymer (P1) is 5 parts by mass, and the preferred upper limit is 30 parts by mass. By having a content of 5 parts by mass or more of the above-mentioned tackifying resin (T1-1), the adhesive strength of the adhesive layer (Y1) can be further improved, and in particular, the adhesive strength to low-polarity adherends (e.g., fluororesins, etc.) can be further improved. By having a content of 30 parts by mass or less of the above-mentioned tackifying resin (T1-1), a decrease in adhesive strength caused by the adhesive layer (Y1) becoming too hard can be suppressed. The more preferred lower limit of the content of the above-mentioned tackifying resin (T1-1) is 10 parts by mass, and the more preferred upper limit is 20 parts by mass. The content of the tackifying resin (T1-1) may be 5 to 30 parts by mass, or 10 to 20 parts by mass.

[0106] The tackifying resin preferably contains at least one tackifying resin (T1-2) selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins. By including the tackifying resin (T1-2), the adhesive strength of the adhesive layer (Y1) can be further improved. In particular, the tackifying resin (T1-2) is more preferably composed of at least one tackifying resin selected from the group consisting of rosin ester resins and terpene resins because it can further improve the adhesive strength to low-polarity adherends (e.g., fluororesins, etc.), and the tackifying resin (T1-2) is even more preferably composed of a rosin ester resin because it can further improve the adhesive strength to low-polarity adherends (e.g., fluororesins, etc.).

[0107] The preferred lower limit of the softening temperature of the tackifying resin (T1-2) is 50°C, and the preferred upper limit is 200°C. A softening temperature of 50°C or higher for the tackifying resin (T1-2) prevents the adhesive layer (Y1) from becoming too soft and reducing its adhesive strength. A softening temperature of 200°C or lower for the tackifying resin (T1-2) improves the wettability of the interface of the adhesive layer (Y1), preventing interfacial delamination. Furthermore, the glass transition temperature (Tg) of the (meth)acrylic copolymer is further reduced. As a result, the flexibility of the adhesive layer (Y1) is further improved, thus improving the adhesive strength of the adhesive layer (Y1) to the fluororesin. A more preferred lower limit of the softening temperature of the tackifying resin (T1-2) is 70°C, and a more preferred upper limit is 150°C. The softening temperature of the tackifying resin (T1-2) may be 50°C to 200°C or 70°C to 150°C. Note that the softening temperature refers to the softening temperature measured according to JIS K 2207 (ring-ball method).

[0108] The preferred lower limit of the hydroxyl value of the tackifying resin (T1-2) is 0 mgKOH / g, and the preferred upper limit is 200 mgKOH / g. Having the hydroxyl value of the tackifying resin (T1-2) within this range improves the wettability of the interface of the adhesive layer (Y1), thereby suppressing interfacial delamination. A more preferred lower limit of the hydroxyl value of the tackifying resin (T1-2) is 30 mgKOH / g, and a more preferred upper limit is 130 mgKOH / g. The hydroxyl value of the above-mentioned tackifying resin (T1-2) may be 0 mg KOH / g to 200 mg KOH / g, or 30 mg KOH / g to 130 mg KOH / g. The above hydroxyl value can be measured according to JIS K 1557 (phthalic anhydride method).

[0109] 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).

[0110] 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).

[0111] 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. The constituent units derived from the phenol compound in the terpene phenol resin do not include the constituent units (A-1) and (A-1') mentioned above. 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).

[0112] 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).

[0113] The preferred lower limit for the content of the tackifying resin (T1-2) per 100 parts by mass of the base polymer (P1) is 10 parts by mass, and the preferred upper limit is 100 parts by mass. A content of 10 parts by mass or more of the tackifying resin (T1-2) can further improve the adhesive strength of the adhesive layer (Y1). A content of 100 parts by mass or less of the tackifying resin (T1-2) can prevent the adhesive layer (Y1) from becoming too hard and reducing its adhesive strength. A more preferred lower limit for the content of the tackifying resin (T1-2) is 15 parts by mass, a more preferred upper limit is 60 parts by mass, an even more preferred upper limit is 50 parts by mass, and an even more preferred upper limit is 40 parts by mass. The content of the tackifying resin (T1-2) may be 10 to 100 parts by mass, 15 to 60 parts by mass, 15 to 50 parts by mass, or 15 to 40 parts by mass.

[0114] 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 crosslinked structure by chemical crosslinking, thereby improving the bulk cohesive force of the adhesive layer (Y1) and increasing the gel fraction of the adhesive layer (Y1), as described later, thus improving the adhesive strength of the resulting adhesive tape. Furthermore, from the viewpoint of storage stability and other factors, the crosslinking agent may be added to the adhesive composition (X1) immediately before forming the adhesive layer (Y1).

[0115] 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).

[0116] Examples of commercially available isocyanate-based crosslinking agents include Coronate L-45 (manufactured by Tosoh Corporation), Takenate 500 (manufactured by Mitsui Chemicals), and Desmodule L-75 (manufactured by Covestro Corporation).

[0117] The preferred lower limit for the content of the crosslinking agent in the above 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 20.0 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 (Y1). 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. The amount of the crosslinking agent may be 0.01 parts by mass to 20.0 parts by mass, 0.1 parts by mass to 10.0 parts by mass, or 0.5 parts by mass to 8.0 parts by mass.

[0118] The above adhesive composition (X1) may further contain a coloring agent for the purpose of providing light-shielding properties. Examples of the coloring agent include carbon black, aniline black, and titanium dioxide. Among these, carbon black is preferred because it is relatively inexpensive and chemically stable.

[0119] 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.

[0120] The preferred lower limit for the gel fraction of the adhesive layer (Y1) is 15% by mass, and the preferred upper limit is 60% by mass. When the gel fraction of the adhesive layer (Y1) is 15% by mass or more, the bulk strength of the adhesive layer (Y1) is increased, and the resulting adhesive tape has superior adhesion. When the gel fraction of the adhesive layer (Y1) is 60% by mass or less, the flexibility of the adhesive layer (Y1) is further improved, and the adhesion strength of the adhesive layer (Y1) to the fluororesin is further improved. The more preferred lower limit for the gel fraction of the adhesive layer (Y1) is 25% by mass, and the more preferred upper limit is 50% by mass. The gel fraction of the adhesive layer (Y1) may be 15% to 60% by mass, or 25% to 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 substrate to which the adhesive layer (Y1) is attached, or the adhesive layer (Y1) alone, into a flat 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. If the base polymer (P1) is a (meth)acrylic copolymer, ethyl acetate can be used as the organic solvent; if the base polymer (P1) is a styrene elastomer or silicone resin, toluene can be used. 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 not laminated with a release film to protect the adhesive layer (Y1). If the test specimen does not have a substrate, W0 is calculated as 0. 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)

[0121] The gel fraction of the adhesive layer (Y1) can be adjusted to within the above range by, for example, adjusting the type and content ratio of monomers constituting the (meth)acrylic copolymer, the weight-average molecular weight of the (meth)acrylic copolymer, the type and content of the crosslinking agent, etc.

[0122] The preferred lower limit for the thickness of the adhesive layer (Y1) is 50 μm, and the preferred upper limit is 1000 μm. The adhesive layer (Y1) having a thickness within this range ensures sufficient adhesive strength. A more preferred lower limit for the thickness of the adhesive layer (Y1) is 100 μm, a more preferred upper limit is 500 μm, and an even more preferred upper limit is 300 μm. The thickness of the adhesive layer (Y1) may be 50 μm to 1000 μm, 100 μm to 500 μm, or 100 μm to 300 μm.

[0123] The adhesive layer (Y2) is formed using the adhesive composition (X2). From the viewpoint of ease of bonding, the adhesive layer (Y2) is preferably a low-tack adhesive layer. Because the adhesive layer (Y2) is a low-tack adhesive layer, stickiness of the adhesive layer (Y2) can be suppressed, resulting in an adhesive tape with superior bonding ease.

[0124] The above adhesive layer (Y2) has a preferred lower limit of 20 N / 5 mmφ for its probe tack value (hereinafter also referred to as "the probe tack value of the adhesive layer (Y2) at 23°C"), measured under the conditions of 23°C, applied pressure of 98 gf, applied pressure of 100 mm / sec, applied pressure for 10 seconds, and pulled-away speed of 5 mm / sec. A probe tack value of 20 N / 5 mmφ or higher for the above adhesive layer (Y2) at 23°C provides adequate adhesive strength, making it easier to adjust the application position of the adhesive tape of the present invention, thus resulting in superior bonding workability. A more preferred lower limit for the probe tack value of the above adhesive layer (Y2) at 23°C is 22 N / 5 mmφ. Furthermore, the preferred upper limit of the probe tack value of the adhesive layer (Y2) at 23°C is 25N / 5mmφ. By having a probe tack value of the adhesive layer (Y2) at 23°C of 25N / 5mmφ or less, the stickiness of the adhesive layer (Y2) can be suppressed, and thus the adhesive tape of the present invention has superior bonding workability. The more preferred upper limit of the probe tack value of the adhesive layer (Y2) at 23°C is 23N / 5mmφ. The probe tack value of the adhesive layer (Y2) at 23°C may be 20N / 5mmφ to 25N / 5mmφ, or 22N / 5mmφ to 23N / 5mmφ. The probe tack value of the adhesive layer (Y2) at 23°C can be measured by a probe tack test in accordance with JIS Z 3284. Specifically, for example, a test piece can be prepared by cutting the adhesive tape of the present invention to a size of 30 mm in width and 30 mm in length. The adhesive layer (Y2) of the prepared test piece can then be tested using a probe tack tester (RHESCA, "TAC-2," etc.) under the following conditions: 23°C, pressurized pressure of 98 gf, pressurization speed of 100 mm / sec, pressurization time of 10 seconds, and release speed of 5 mm / sec.

[0125] Methods for adjusting the probe tack value of the adhesive layer (Y2) at 23°C include changing the composition and content ratio of the base polymer (P2) and the tackifying resin (T2) described later, and changing the thickness of the adhesive layer (Y2).

[0126] The adhesive layer (Y2) preferably contains a base polymer (P2). The above-mentioned base polymer (P2) preferably contains at least one selected from the group consisting of (meth)acrylic copolymer, styrene elastomer, ethylene-vinyl acetate copolymer, chloroprene rubber, nitrile rubber, polyurethane resin, polyamide resin, polyolefin resin, polyester resin, epoxy resin, and silicone resin. In particular, from the viewpoint of making it easier to adjust the probe tack value and improving heat resistance, it is preferable to include at least one selected from the group consisting of (meth)acrylic copolymer and styrene elastomer. Furthermore, from the viewpoint of suppressing contamination of the adherend, it is preferable that the above-mentioned base polymer (P2) is a base polymer other than silicone resin.

[0127] Examples of the (meth)acrylic copolymer, styrene-based elastomer, and silicone resin in the above-mentioned base polymer (P2) are the same as those used in the above-mentioned base polymer (P1).

[0128] Examples of commercially available ethylene-vinyl acetate copolymers include HM200 (manufactured by Cemedyne Co., Ltd.). Examples of commercially available chloroprene rubbers 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.). Examples of commercially available polyurethane resins include SHM107-PUR (manufactured by Seedam Corporation). Examples of commercially available polyamide resins include SHM301-PAD (manufactured by Seedam Corporation). Examples of commercially available polyolefin resins include PPET1200F (manufactured by Toagosei Co., Ltd.). Examples of commercially available polyester resins include PH-413 (manufactured by Nippon Matai Co., Ltd.). Examples of commercially available epoxy resins include 1500 (manufactured by Cemedyne Co., Ltd.).

[0129] 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. By keeping the content of the base polymer (P2) within this range, the adhesive properties such as peel strength and holding strength of the adhesive layer (Y2) can be well-balanced. The more preferred lower limit for the content of the base polymer (P2) is 75% by mass, and the more preferred upper limit is 90% by mass. The content of the above base polymer (P2) may be 50% to 99% by mass, or 75% to 90% by mass.

[0130] The above adhesive composition (X2) preferably contains a tackifying resin (T2) from the viewpoint of further improving adhesive strength. The above 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 (T1-2) described above.

[0131] 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 100 parts by mass. A content of 10 parts by mass or more of the tackifying resin (T2) can further improve the adhesive strength of the adhesive layer (Y2). A content of 100 parts by mass or less of the tackifying resin (T2) can prevent the adhesive layer (Y2) from becoming too hard and reducing its adhesive strength. A more preferred lower limit for the content of the tackifying resin (T2) is 20 parts by mass, and a more preferred upper limit is 80 parts by mass. The content of the tackifying resin (T2) may be 10 to 100 parts by mass, or 20 to 80 parts by mass.

[0132] The adhesive composition (X2) 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, resulting in an adhesive tape with superior adhesion. Furthermore, from the viewpoint of storage stability and other factors, the crosslinking agent may be added to the adhesive composition (X2) immediately before forming the adhesive layer (Y2).

[0133] 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). Examples of the above-mentioned isocyanate-based crosslinking agent and epoxy-based crosslinking agent include those the same as those used in the above-mentioned adhesive composition (X1).

[0134] The preferred lower limit for the content of the crosslinking agent in the above 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. The amount of the crosslinking agent may be 0.1 to 10 parts by mass, or 0.5 to 5 parts by mass.

[0135] From the viewpoint of further improving adhesive strength, the above adhesive composition (X2) preferably contains a silane coupling agent. 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. The silane coupling agents described above may be used individually or in combination of two or more.

[0136] 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 3 parts by mass. A content of 0.1 parts by mass or more of the silane coupling agent can further improve the adhesive strength of the adhesive layer (Y2). A content of 3 parts by mass or less of the silane coupling agent can 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 parts by mass. The content of the silane coupling agent may be 0.1 to 3 parts by mass, or 0.5 to 2 parts by mass.

[0137] 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.

[0138] 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 tape 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) may be 15% to 60% by mass, or 25% to 50% by mass. The gel fraction of the adhesive layer (Y2) can be measured using the same method as described above for the gel fraction of the adhesive layer (Y1).

[0139] The gel fraction of the adhesive layer (Y2) can be adjusted to within the above range by, for example, adjusting the type and content ratio of monomers constituting the (meth)acrylic copolymer, the weight-average molecular weight of the (meth)acrylic copolymer, the type and content of the crosslinking agent, etc.

[0140] The preferred lower limit for the thickness of the adhesive layer (Y2) is 50 μm, and the preferred upper limit is 1000 μm. By having the thickness of the adhesive layer (Y2) within this range, the adhesive layer (Y2) will have sufficient adhesive strength. A more preferred lower limit for the thickness of the adhesive layer (Y2) is 100 μm, and a more preferred upper limit is 700 μm. The thickness of the adhesive layer (Y2) may be 50 μm to 1000 μm, or 100 μm to 700 μm.

[0141] The adhesive tape of the present invention has a base material. Because the adhesive tape of the present invention has a base material, the resulting adhesive tape has excellent workability when being bonded.

[0142] From the viewpoint of heat resistance and chemical resistance, the above-mentioned substrate preferably contains at least one selected from the group consisting of polyester resin, polyimide resin, polyether resin, polyolefin resin, polyurethane resin, metal, glass fiber, and carbon fiber.

[0143] Furthermore, the generation of air at the adhesive surface when the above-mentioned substrate is pressed against the adhesive layer can cause the adhesive layer to peel off easily. Therefore, it is preferable that the above-mentioned substrate includes at least one shape selected from the group consisting of nonwoven fabrics and woven fabrics, as this improves the anchoring strength of the substrate and improves air release properties by providing air passages to suppress air generation, thereby suppressing the peeling of the adhesive layer.

[0144] Examples of commercially available nonwoven fabric-like base materials include G2260-1S (manufactured by Toray International, Inc.). Examples of the woven base material mentioned above include glass cloth and carbon cloth. Examples of commercially available glass cloths among those mentioned above include KS2770 (manufactured by Nitto Boseki Co., Ltd.) and L73A×1045 (manufactured by Arisawa Seisakusho Co., Ltd.). Among the carbon cloths mentioned above, commercially available examples include C-540 (manufactured by Hagiwara Industries Co., Ltd.).

[0145] The preferred lower limit for the thickness of the above 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 resulting adhesive tape. A more preferred lower limit for the thickness of the above substrate is 100 μm, and a more preferred upper limit is 500 μm. The thickness of the above-mentioned substrate may be 50 μm to 1000 μm, or 100 μm to 500 μm.

[0146] The method for manufacturing the adhesive tape 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), a tackifying resin (T1), and, if necessary, a crosslinking agent or solvent. The obtained adhesive solution (a) is applied to the release 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 a laminate having an adhesive layer (Y1) on one side of the substrate. Note that the step of applying the adhesive solution (a) to the release 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), a tackifying resin (T2), and, if necessary, a crosslinking agent or solvent. The obtained adhesive solution (b) is applied to the release 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. Note that the step of applying the adhesive solution (b) to the release surface of the release PET film may be performed once, 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 (Y2) can be easily adjusted. By overlapping a substrate with a laminate having an adhesive layer (Y1) on one side of the substrate, the side of the substrate without the adhesive layer (Y1), and a laminate film having an adhesive layer (Y2) formed on a release PET film, so that they face each other, and curing for 48 hours in an environment of 40°C and 50%RH, an adhesive tape can be obtained 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.

[0147] The adhesive tape of the present invention is not particularly limited in its applications, but because it has excellent adhesive strength to fluororesins such as polytetrafluoroethylene without pretreatment to the fluororesin, it is suitably used for joining fluororesins 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 is suitably used to protect adherends, and especially suitably used to protect adherends from chemical solutions. Furthermore, because the adhesive tape of the present invention can suppress peeling of the substrate and provide high-strength adhesion, it is more suitably used when joining lining sheets to tank bodies in chemical solution tanks for semiconductors or chemical solution tanks for the chemical industry.

[0148] A laminated sheet having a sheet containing fluororesin on the adhesive layer (Y1) side of the adhesive tape 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.

[0149] 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.

[0150] 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 tanks for semiconductors or chemical tanks for the chemical industry, or for piping used to transport chemical solutions, as a coating material for electronic equipment components, or as a building material. In particular, the laminated sheet of the present invention is suitably used for lining (surface treatment covering the inner surface of a can) of cans in chemical tanks for semiconductors or chemical tanks for the chemical industry.

[0151] A chemical tank in which the adhesive tape or laminated sheet of the present invention is attached to the inner surface of a can is also one of the present inventions. The chemical tank of the present invention allows for strong bonding of fluororesin to the inner surface of the tank body via the adhesive tape of the present invention or the adhesive layer (Y1) in the laminated sheet of the present invention, thereby further suppressing peeling and lifting of the fluororesin caused by the chemical solution stored in the chemical tank to which the fluororesin is bonded.

[0152] 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 (Y1) of the adhesive tape of the present invention; and attaching the adhesive layer (Y2) of the laminated sheet to the inner surface of the tank body of the chemical tank. [Effects of the Invention]

[0153] According to the present invention, it is possible to provide an adhesive tape that offers excellent workability and reliability when bonding fluororesin to a can or the like. Furthermore, according to the present invention, it is possible to provide a laminated sheet having the adhesive tape. Moreover, according to the present invention, it is possible to provide a chemical tank to which the adhesive tape 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 tape and the laminated sheet. [Brief explanation of the drawing]

[0154] [Figure 1] This diagram schematically illustrates a method for evaluating the holding power of adhesive tape. [Modes for carrying out the invention]

[0155] 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.

[0156] (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.

[0157] (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.

[0158] The constituent monomers shown in Table 1 are as follows: BA: n-butyl acrylate 2EHA:2-Ethylhexylacrylate nHA:n-heptylacrylate HEA: 2-hydroxyethyl acrylate AAc: Acrylic acid

[0159] [Table 1]

[0160] (Preparation of tackifying resin (T1-1)) (Synthesis example A) 50 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) (n=2) 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 (T1-1). Regarding the obtained tackifying resin (T1-1) 1 ¹H-NMR measurements were performed to confirm that the tackifying resin (T1-1) is a copolymer having constituent units (A) derived from catechol (pyrocatechol) and constituent units (B) derived from α-pinene (a copolymer having constituent unit (A) in or at the ends of the main chain skeleton). The obtained tackifying resin (T1-1) 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 (T1-1) and determine the weight-average molecular weight (Mw). A GPC KF-802.5L column (Showa Denko) was used, and a differential refractometer was used as the detector. The results are shown in Table 2.

[0161] (Measurement of the bio-derived carbon content of tackifying resin (T1-1)) The bio-derived carbon content of the obtained tackifying resin (T1-1) was measured according to ASTM D6866-22. The results are shown in Table 2.

[0162] (Synthesis examples B-C and E) In the above-mentioned "(Preparation of Tackifying Resin (T1-1))", the tackifying resin (T1-1) was synthesized in the same manner as in "(Synthesis Example A)", except that the constituent unit monomers were changed as shown in Table 2, and measurements were performed. The results are shown in Table 2.

[0163] (Synthesis example D) (Preparation of tackifying resin (T1-1)) 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, while maintaining the toluene at 75°C, two parts by mass of aluminum chloride (AlCl3) were added. A solution of 70 parts by mass of 4-vinylbenzoic acid (m=1) 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 (T1-1). Regarding the obtained tackifying resin (T1-1) 1 ¹H-NMR measurements were performed to confirm that the tackifying resin (T1-1) is a copolymer having structural units (A) derived from 4-vinylbenzoic acid and structural units (B) derived from α-pinene (a copolymer having structural unit (A) in its side chains). The obtained tackifying resin (T1-1) 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 (T1-1) and determine the weight-average molecular weight (Mw). A GPC KF-802.5L column (Showa Denko) was used, and a differential refractometer was used as the detector. The results are shown in Table 2.

[0164] (Measurement of the bio-derived carbon content of tackifying resin (T1-1)) The bio-derived carbon content of the obtained tackifying resin (T1-1) was measured according to ASTM D6866-22. The results are shown in Table 2.

[0165] [Table 2]

[0166] (Example 1) (1) Making adhesive tape To 100 parts by mass of the solid content of the acrylic copolymer obtained in Synthesis Example 1 as the base polymer (P1), 10 parts by mass of the tackifying resin (T1-1) obtained in Synthesis Example B was added, along with 10 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") as tackifying resins (T1-2). Furthermore, 30 parts by mass of ethyl acetate (Fuji Chemical Co., Ltd.) and 0.5 parts 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 100 μm thick adhesive layer (Y1) on the release PET film, thereby producing a laminated film. A 50 μm thick PET film (Futamura Chemical Co., Ltd., "FE2002") was prepared as a substrate, and the prepared laminated film was placed on top of the substrate so that the adhesive layer (Y1) faced the substrate, and then cured by heating at 40°C for 48 hours. This resulted in obtaining a laminate having a substrate and an adhesive layer (Y1) on one side of the substrate. Furthermore, 30 parts by mass of terpene phenol resin (Yasuhara Chemical Co., Ltd., "YS Polystar G150") was added as a tackifying resin (T2) to 100 parts by mass of the solid content of the acrylic copolymer obtained in Synthesis Example 1 as the base polymer (P2). In addition, 30 parts by mass of ethyl acetate (Fuji Chemical Co., Ltd.) and 1.5 parts by mass of isocyanate crosslinking agent (Covestro Co., Ltd., "Desmodule L-75") were added and 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 an adhesive layer (Y2) with a thickness of 100 μm on the release PET film, thereby producing a laminated film. An adhesive tape was obtained by overlapping a substrate with a laminate having an adhesive layer (Y1) on one side of the substrate, where the side of the substrate without the adhesive layer (Y1) is facing the adhesive layer (Y2) of a laminate film having an adhesive layer (Y2) formed on a release PET film, and curing it for 48 hours in an environment of 40°C and 50%RH.

[0167] (2) Measurement of the gel fraction of the adhesive layer (Y1) Only the adhesive layer (Y1) was extracted from the obtained adhesive tape, cut into a flat rectangular shape measuring 50 mm wide x 100 mm long to prepare a test specimen, 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.

[0168] (3) Measurement of the probe tack value of the adhesive layer (Y2) at 23°C Test specimens were prepared by cutting the obtained adhesive tape to a size of 30 mm wide x 30 mm long. A probe tack test was performed on the adhesive layer (Y2) of the obtained test specimens using a probe tack tester (RHESCA, "TAC-2") under the following conditions: 23°C, applied pressure of 98 gf, applied speed of 100 mm / sec, applied for 10 seconds, and released speed of 5 mm / sec. The probe tack value of the adhesive layer (Y2) at 23°C was measured. The results are shown in Table 3.

[0169] (4) Measurement of the gel fraction of the adhesive layer (Y2) Only the adhesive layer (Y2) was extracted from the obtained adhesive tape, cut into a flat rectangular shape measuring 50 mm wide x 100 mm long to prepare a test specimen, 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.

[0170] (5) Measurement of the 180° peel force of the adhesive layer (Y1) against PTFE at 23°C The obtained adhesive tape was cut to a size of 25 mm wide x 100 mm long. Then, using a 2 kg rubber roller, the adhesive layer (Y1) side was pressed onto a 2 mm thick polytetrafluoroethylene sheet (Yodogawa Hutech Co., Ltd., "Yodoflon") by one back-and-forth motion at a speed of 300 mm / min. The sheet was then left to stand for 20 minutes in an environment of 23°C and 50% RH. After that, laminate A was prepared by curing. A 180° peel test was performed on the obtained laminate A using a tensile testing machine (ORIENTEC Co., Ltd., "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 (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.

[0171] (6) 180° peel strength of the adhesive layer (Y2) after heating relative to SUS at 23°C The obtained adhesive tape was backed with a 1.0 mm thick polytetrafluoroethylene plate to create the adhesive layer (Y1), and then cut to a size of 25 mm wide x 100 mm long. Next, the adhesive layer (Y2) side was placed on a thick SUS plate (SUS304 plate that had been washed with ethanol and then wiped dry), and laminate B was fabricated by pressing it under pressure at 0.1 MPa for 1 hour in an environment of 120°C. For the obtained laminate B, a 180° peel test was performed 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 30 mm / min. The 180° peel force of the heated adhesive layer (Y2) relative to SUS at 23°C was measured by peeling the adhesive tape from the SUS plate. The results are shown in Table 3.

[0172] (7) 180° peel strength of the adhesive layer (Y2) on SUS at 80°C after heating For laminate B, obtained in the same manner as described in "(6) 180° peel force of the heated adhesive layer (Y2) relative to SUS at 23°C," a 180° peel test was performed using a tensile testing machine (ORIENTEC, "Tensilon") in accordance with JIS Z 0237, under conditions of 80°C, 50%RH, and a peeling speed of 30 mm / min. The 180° peel force of the heated adhesive layer (Y2) relative to SUS at 80°C was measured by peeling the adhesive tape from the SUS plate. The results are shown in Table 3.

[0173] (Examples 2-43, Comparative Examples 1-4) In the above-mentioned "(1) Preparation of adhesive tape," adhesive tape 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 9. The results are shown in Tables 3 to 9.

[0174] <Rating> The obtained adhesive tapes were evaluated using the following method. The results are shown in Tables 3-9.

[0175] (Bonding reliability) The obtained adhesive tape was backed with the adhesive layer (Y1) using a corona-treated PET film, and then cut to a size of 20 mm wide x 50 mm long. Next, the adhesive layer (Y2) side was attached to a polycarbonate resin plate and cured overnight at 23°C and 50% RH to obtain test specimens. Subsequently, a constant load peel test was performed by applying a 50 g load to the edge of the PET film at a 90° angle to the surface at 23°C, and measuring the peel length of the adhesive tape after 1 hour. The same constant load peel test was also performed on the test specimens obtained in the same manner at 85°C. The bonding reliability was evaluated according to the following criteria. ◎: If the peeled length of the adhesive tape is 10 mm or less. ○: When the peeled length of the adhesive tape exceeds 10 mm but is 25 mm or less. △: If the peeled length of the adhesive tape exceeds 25 mm but is 50 mm or less. ×: If the peeled length of the adhesive tape exceeds 50 mm, or if the adhesive tape falls off. Even if a product receives a "×" rating in a constant-load peel test at 85°C, it can still be used without problems depending on the application.

[0176] (Ease of bonding) For laminate B obtained in the same manner as described in "(6) 180° peel strength of the adhesive layer (Y2) after heating relative to SUS at 23°C", the presence or absence of wrinkles in the polytetrafluoroethylene plate was visually confirmed, and the wrinkle prevention performance during bonding was evaluated according to the following criteria. ○: If it was applied without wrinkles △: If wrinkles are found in some areas ×: If numerous wrinkles are observed Furthermore, the obtained adhesive tape was backed with a 1.0 mm thick polytetrafluoroethylene board to create the adhesive layer (Y1), and then cut to a size of 25 mm wide x 100 mm long. Next, the side with the adhesive layer (Y2) was gently placed on a SUS plate (a SUS304 plate measuring 50 mm wide x 200 mm long x 2 mm thick, which had been washed with ethanol and then wiped dry) without applying any load. After 10 seconds, the adhesive tape was lifted to check if it was fixed to the SUS plate, and the ease of positioning and temporary fixing was evaluated according to the following criteria. ○: If the SUS is lifted for more than 3 seconds △: If the SUS is lifted for more than 1 second but less than 3 seconds ×: If the SUS is lifted for less than 1 second, or if the SUS cannot be lifted. Even if the evaluation result for ease of alignment and temporary fixing is "×", it can still be used without problems depending on the application.

[0177] (retention) The release PET film on the adhesive layer (Y2) side of the obtained adhesive tape was peeled off, cut into 25mm wide strips, and bonded to a SUS plate (SUS304 plate washed with ethanol and then wiped dry) by running a 2kg rubber roller back and forth once at a speed of 300mm / min. Next, cuts were made in the adhesive tape so that the bonding area was 25mm x 25mm, and the test sample was prepared by letting it stand at 23°C for 20 minutes. The prepared test sample was placed in an 80°C oven and heated for another 20 minutes, and then a 500g weight was suspended under 80°C and 50%RH conditions as shown in Figure 1 to apply a load in the shear direction. The amount of displacement (movement) (mm) from the cut position one hour after the load was applied was measured with a scale loupe. The obtained displacement amount (mm) was used to evaluate the retention performance according to the following criteria. ○: If the displacement is 0 mm or more but less than 1 mm △: If the displacement is 1 mm or more but less than 2 mm ×: If the displacement is 2 mm or more, or if the adhesive tape falls off. Even if the evaluation result of the retention property is "×", it can be used without problems depending on the application.

[0178] (Low adhesion body contamination) After the 180° peel test of the adhesive tape in the above-mentioned "(5) Measurement of the 180° peel force of the adhesive layer (Y1) against PTFE at 23°C", XPS measurement was performed using a scanning X-ray photoelectron spectrometer (manufactured by ULVAC-PHI, Inc., "PHI 5000 VersaProbe II") to measure the silicon atom concentration (at%) on the adhesive tape peel surface of the PTFE plate. After the 180° peel test of the adhesive tape in the above-mentioned "(6) 180° peel force of the adhesive layer (Y2) against SUS at 23°C after heating", the silicon atom concentration (at%) was similarly measured for the surface of the SUS plate from which the adhesive tape was peeled. The XPS measurement was performed under the following conditions. <Measurement conditions> X-ray source: Monochromatic AlKα (1486.6 eV) Spectrometer: Electrostatic concentric hemispherical analyzer Photoelectron extraction angle: 45 degrees Charge neutralization: Yes X-ray beam diameter: 200 μm Pass energy: 117 eV Using the obtained silicon atom concentration (at%), the contamination of the adherend by the adhesive tape was evaluated according to the following criteria. ○: For both PTFE and SUS, the silicon atom concentration was 1.0 at% or less. ×: For at least one of PTFE and SUS, the silicon atom concentration was greater than 1.0 at%. Even if the evaluation result of the adherend contamination is "×", it can be used without problems depending on the application.

[0179]

Table 3

[0180]

Table 4

[0181] [Table 5]

[0182] [Table 6]

[0183] [Table 7]

[0184] [Table 8]

[0185] [Table 9] [Industrial applicability]

[0186] According to the present invention, it is possible to provide an adhesive tape that offers excellent workability and reliability when bonding fluororesin to a can or the like. Furthermore, according to the present invention, it is possible to provide a laminated sheet having the adhesive tape. Moreover, according to the present invention, it is possible to provide a chemical tank to which the adhesive tape 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 tape and the laminated sheet. [Explanation of Symbols]

[0187] 1 Adhesive tape 2 SUS304 plate 3,500g weight

Claims

1. An adhesive tape comprising a base material, an adhesive layer (Y1) formed on one surface of the base material using an adhesive composition (X1), and an adhesive layer (Y2) formed on the other surface of the base material using an adhesive composition (X2), The adhesive tape has a thickness of 250 μm or more. After backing the adhesive layer (Y2) with a PET film with a thickness of 50 μm, the adhesive layer (Y1) is bonded to a polytetrafluoroethylene board, and the resulting laminate A is left to stand at 23°C for 24 hours. In accordance with JIS Z 0237, the 180° peel force of the adhesive layer (Y1) relative to the polytetrafluoroethylene board is 5 N / 25 mm or more, measured at 23°C and a peeling rate of 300 mm / min. Laminate B, obtained by backing the adhesive layer (Y1) with a 1.0 mm thick polytetrafluoroethylene board, then bonding the adhesive layer (Y2) to a SUS304 board and heating at 120°C for 1 hour, has a 180° peel force of 40 N / 25 mm or more on the adhesive layer (Y2) side relative to the SUS304 board, measured at 23°C and a peel rate of 30 mm / min in accordance with JIS Z 0237. An adhesive tape characterized by the following features.

2. The adhesive composition (X1) contains a base polymer (P1), The adhesive tape according to claim 1, wherein the base polymer (P1) comprises at least one selected from the group consisting of (meth)acrylic copolymers and styrene-based elastomers.

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

4. The adhesive tape according to claim 3, wherein the tackifying resin (T1) comprises a tackifying resin (T1-1) having at least one constituent unit (A) selected from the group consisting of constituent units (A-1), (A-1'), (A-2), (A-2'), (A-3), (A-3'), (A-4), and (A-4') represented by the following formula. 【Chemistry 1】 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 In the formula, R １ ~R ７ Each represents a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a group having a polar functional group. n and l each represent integers between 2 and 4, and n' and l' each represent integers between 2 and 5. m and k each represent integers between 1 and 4, and m' and k' each represent integers between 1 and 5. * represents a linking part.

5. The adhesive tape according to claim 3, wherein the tackifying resin (T1) comprises at least one tackifying resin (T1-2) selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins.

6. The adhesive tape according to claim 1 or 2, wherein the adhesive composition (X1) contains a crosslinking agent.

7. The adhesive tape according to claim 6, wherein the crosslinking agent comprises at least one selected from the group consisting of isocyanate-based crosslinking agents and epoxy-based crosslinking agents.

8. The adhesive tape according to claim 1 or 2, wherein the adhesive layer (Y1) has a gel fraction of 15% by mass or more and 60% by mass or less.

9. The adhesive tape according to claim 1 or 2, wherein the adhesive layer (Y1) has a thickness of 50 μm or more and 1000 μm or less.

10. The adhesive composition (X2) contains a base polymer (P2), The adhesive tape according to claim 1, wherein the base polymer (P2) comprises at least one selected from the group consisting of (meth)acrylic copolymers and styrene-based elastomers.

11. The adhesive tape according to claim 1 or 10, wherein the adhesive composition (X2) contains a tackifying resin (T2), and the tackifying resin (T2) comprises at least one tackifying resin selected from the group consisting of rosin ester resins, terpene resins, terpene phenol resins, and petroleum resins.

12. The adhesive tape according to claim 1 or 10, wherein the adhesive composition (X2) contains a silane coupling agent.

13. The adhesive tape according to claim 1 or 10, wherein the adhesive composition (X2) contains a crosslinking agent.

14. The adhesive tape according to claim 13, wherein the crosslinking agent comprises at least one selected from the group consisting of isocyanate-based crosslinking agents and epoxy-based crosslinking agents.

15. The adhesive tape according to claim 1 or 10, wherein the adhesive layer (Y2) has a gel fraction of 15% by mass or more and 60% by mass or less.

16. The adhesive tape according to claim 1 or 10, wherein the adhesive layer (Y2) has a probe tack value of 20 N / 5 mmφ or more, measured under the conditions of 23°C, pressurized pressure of 98 gf, pressurizing speed of 100 mm / sec, pressurizing time of 10 seconds, and release speed of 5 mm / sec.

17. The adhesive tape according to claim 1 or 10, wherein the adhesive layer (Y2) has a thickness of 50 μm or more and 1000 μm or less.

18. The adhesive tape according to claim 1, wherein the substrate contains at least one selected from the group consisting of polyester resin, polyimide resin, polyether resin, polyolefin resin, polyurethane resin, metal, glass fiber, and carbon fiber.

19. The adhesive tape according to claim 1 or 18, wherein the base material comprises a base material in at least one shape selected from the group consisting of nonwoven fabric and woven fabric.

20. The adhesive tape according to claim 1 or 18, wherein the substrate has a thickness of 50 μm or more and 1000 μm or less.

21. The adhesive tape according to claim 1, wherein the laminate B obtained by backing the adhesive layer (Y1) with a 1.0 mm thick polytetrafluoroethylene plate, then bonding the adhesive layer (Y2) to a SUS304 plate, and heating at 120°C for 1 hour, has a 180° peel force of 20 N / 25 mm or more on the adhesive layer (Y2) side relative to the SUS304 plate, measured in accordance with JIS Z 0237 under conditions of 80°C and a peel rate of 30 mm / min.

22. The adhesive tape according to claim 1 or 21, used for lining the body of a chemical tank for semiconductors or a chemical tank for the chemical industry.

23. A laminated sheet having a sheet containing fluororesin on the adhesive layer (Y1) side of the adhesive tape according to claim 1.

24. A laminated sheet according to claim 23, used for protecting an adherend.

25. A laminated sheet according to claim 24, used to protect an adherend from a chemical solution.

26. A chemical tank having the adhesive tape described in claim 1 or the laminated sheet described in claim 23 attached to the inner surface of the can body.

27. A step of producing a laminated sheet according to claim 23, 24, or 25 by pressing a sheet containing fluororesin onto the adhesive layer (Y1) of the adhesive tape according to claim 1, A method for manufacturing a chemical tank, comprising the step of attaching the adhesive layer (Y2) of the laminated sheet to the inner surface of the tank body of the chemical tank.

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