Adhesive tape, article, and method for dismantling an article

Abstract

The present invention provides an adhesive tape which is able to be removed by heating in a short time, while being capable of preventing thermal damage to an adherend, and which is removed by heating by an easy operation.　The present invention provides an adhesive tape which comprises an adhesive layer A that contains a heating element and an adhesive, wherein: the heating element has a volume resistivity of 30 µΩ∙cm or more; and the adhesive layer A is melted or softened by means of resistance heating, thereby becoming removable. It is preferable that the adhesive is composed of at least one of a pressure sensitive adhesive and a hot melt adhesive; and it is preferable that the heating element is selected from the group consisting of Nichrome, stainless steel, titanium, nickel silver, and carbon.

Description

[Technical Field]

[0001] The present invention relates to an adhesive tape, an article, and a method for dismantling an article. [Background technology]

[0002] As a joining means with excellent workability and adhesive reliability, adhesive tape is used in various industrial fields such as office automation equipment, IT products, home appliances, and automobiles for applications such as fixing parts, temporarily fixing parts, and labeling to display product information. In recent years, from the perspective of protecting the global environment, there has been an increasing demand for the recycling and reuse of used products in various industrial fields such as home appliances and automobiles. When recycling or reusing various products, it is necessary to remove the adhesive tape used to fix parts and for labels. However, because adhesive tape is applied in various places within the product, there is a demand for a simple removal process that reduces labor costs.

[0003] In order to separate adherends from each other, for example, a hot melt adhesive composition that dissolves quickly in a short time by electromagnetic induction heating has been proposed (see, for example, Patent Document 1).As a method for separating adherends from each other, a building demolition method has been proposed in which a metal base material is heated by an electromagnetic induction heating device, the adhesive between this base material and interior material is heated and foamed to separate it, and the interior material is peeled off from the metal base material (see, for example, Patent Document 2). Also proposed is a double-sided adhesive tape having a heat conductive layer that can be easily dismantled by contacting it with a heat generating source and directly heating the heat conductive layer (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-188068 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-200279 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-108394 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional methods for peeling and dismantling by heating require the use of external devices as heating means, such as electromagnetic induction heating or a heat generating source, which results in the problem of large-scale dismantling work. Furthermore, when the heating method is electromagnetic induction heating or infrared heating, heat is applied from the outside, and therefore, when heating an adhesive tape incorporated into a component, the adhesive tape may not be heated sufficiently, and it may be difficult to adjust the heating temperature to a level at which the adhesive tape can be peeled. In particular, in electronic components that are completely shielded from the outside, it is difficult to heat only the adhesive tape, and if heating takes a long time, the adherend may be exposed to high temperatures, resulting in thermal degradation.

[0006] Therefore, there is a demand for adhesive tapes that can be used to fasten adherends such as rigid bodies together, and that have the ability to dismantle and reuse the adherend components. In particular, there is a demand for adhesive tapes that can be easily dismantled and peeled off by heating.

[0007] The present invention aims to solve the above-mentioned conventional problems and to achieve the following object: That is, the present invention aims to provide a pressure-sensitive adhesive tape, an article, and a method for dismantling an article, which can be thermally peeled in a short time, can prevent thermal damage to an adherend, and is easy to perform the thermal peeling operation. [Means for solving the problem]

[0008] The present invention is based on the above findings of the present inventors, and the means for solving the above problems are as follows: <1> This adhesive tape has an adhesive layer A containing a heating element and an adhesive, the volume resistivity of the heating element being 30 μΩ·cm or more, and the adhesive layer A melting or softening due to resistance heating makes it peelable. <2> The adhesive is at least one of a pressure-sensitive adhesive and a hot-melt adhesive. <1> 1. The adhesive tape according to claim 1. <3> The heating element is selected from the group consisting of nichrome, stainless steel, titanium, nickel silver, and carbon. <1> From the above <2> The adhesive tape according to any one of the above items. <4> The adhesive layer A is a laminate having a planar heating element and an adhesive layer a1 and an adhesive layer a2 on each surface of the heating element, and at least one of the adhesive layer a1 and the adhesive layer a2 is melted or softened by resistance heating and becomes peelable. <1> From the above <3> The adhesive tape according to any one of the above items. <5> In a plan view, the planar heating element has a pair of extension portions extending from the outer peripheries of the adhesive layer a1 and the adhesive layer a2. <4> 1. The adhesive tape according to claim 1. <6> The adhesive layer A is a single layer containing the heating element and the adhesive. <1> From the above <3> The adhesive tape according to any one of the above items. <7> The temperature at which the loss tangent (tanδ) of the adhesive layer formed by the adhesive is 0.45 or more is in the temperature range of 80°C or more and 200°C or less. <1> from <6> 10. The adhesive tape according to claim 9, wherein <8> At least two adherends and the above-mentioned adhesive tape between the two adherends. <1> from <7> and the adhesive tape according to any one of the above items 1 to 4, wherein two adherends are bonded together via the adhesive tape. <9> In a plan view, the adhesive tape has a pair of extension portions extending from the outer periphery of the adherend. <8> The article is described in <10> The aforementioned <8> from <9> The method for dismantling an article described in any one of the above items is characterized in that the adhesive layer A is electrically connected to a power source, electricity is passed from the power source to the heating element, and the adhesive layer A is softened or melted by resistance heating to separate the two adherends. <11> The power source is an external power source. <10> This is a method for dismantling the article described in the above. <12> The article is an electronic device or a component built into an electronic device, the power source is a driving power source for the electronic device, the adhesive layer A is electrically connected to the driving power source and the electric circuit of the electronic device, and electricity is passed from the driving power source to the heating element, and the adhesive layer A is melted or softened by resistance heating to separate the two adherends. <10> This is a method for dismantling the article described in the above. [Effects of the Invention]

[0009] According to the present invention, it is possible to solve the above-mentioned problems in the prior art, achieve the above-mentioned object, and provide an adhesive tape, an article, and a method for dismantling an article that can be thermally peeled in a short time, can prevent thermal damage to an adherend, and is easy to perform the thermal peeling operation. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1A is a schematic cross-sectional view showing an example of the pressure-sensitive adhesive tape of the present invention. [Figure 1B] FIG. 1B is a schematic cross-sectional view showing another example of the pressure-sensitive adhesive tape of the present invention. [Figure 1C] FIG. 1C is a schematic plan view showing another example of the pressure-sensitive adhesive tape of the present invention. [Figure 1D] FIG. 1D is a schematic plan view showing an example of the pattern of the heating element in the pressure-sensitive adhesive tape of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing another example of the pressure-sensitive adhesive tape of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view showing another example of the pressure-sensitive adhesive tape of the present invention. [Figure 4A] FIG. 4A is a schematic plan view showing an example of the article of the present invention. [Figure 4B] FIG. 4B is a schematic cross-sectional view showing an example of the article of the present invention. [Figure 5] FIG. 5 is a schematic cross-sectional view showing another example of the article of the present invention. [Figure 6] FIG. 6 is a diagram showing a schematic diagram of a method for dismantling an article according to the present invention. [Figure 7A]FIG. 7A is a schematic plan view of the pressure-sensitive adhesive tape of Example 1. FIG. [Figure 7B] FIG. 7B is a schematic cross-sectional view of the pressure-sensitive adhesive tape of Example 1. [Figure 8A] FIG. 8A is a schematic plan view showing the article of Example 1 and the evaluation method. [Figure 8B] FIG. 8B is a schematic front view showing the article of Example 1 and the evaluation method. [Figure 8C] FIG. 8C is a schematic side view showing the article of Example 1 and the evaluation method. DETAILED DESCRIPTION OF THE INVENTION

[0011] In this specification, "adhesion" refers to a type of adhesion, and refers to adhesion by pressure, and is also called "pressure-sensitive adhesion." Correspondingly, "adhesive" refers to an adhesive that has both liquid and solid properties, is sticky (tacky), and adheres when pressure is applied, and is also called a "pressure-sensitive adhesive."

[0012] 1. Adhesive tape The pressure-sensitive adhesive tape of the present invention has at least an adhesive layer A containing a heating element and an adhesive, and may further have other layers such as a release layer. The pressure-sensitive adhesive tape of the present invention is a pressure-sensitive adhesive tape in which the adhesive layer A melts or softens when subjected to resistance heating, thereby becoming peelable.

[0013] The pressure-sensitive adhesive tape of the present invention can be used as an easily dismantled pressure-sensitive adhesive tape that can be easily disassembled after a certain period of time has passed after being applied to an adherend and fixing the adherends together. That is, by electrically connecting the adhesive layer A to a power source and applying a voltage to the heating element to pass electricity, the heating element and its surroundings are heated by resistance heating. As a result, the adhesive or any melt-softening layer in the adhesive layer A softens or melts, and the adhesive layer A itself or a desired position within the adhesive layer A is released from its adhesive state, making the adhesive layer A peelable and the bonded adherends dismantled. In the adhesive tape of the present invention, current is passed directly through the heating element when the tape is dismantled, making it easy to adjust the amount of current, etc., and by using a heating element with a predetermined volume resistivity, thermal peeling is possible in a short period of time. Compared with conventional heating methods such as electromagnetic induction heating and infrared heating, the pressure-sensitive adhesive tape of the present invention can generate heat only within the pressure-sensitive adhesive tape, making it easier to adjust the heating even when the pressure-sensitive adhesive tape is incorporated into a component, and preventing excessive heating of the adherend. Furthermore, when the pressure-sensitive adhesive tape is thermally disassembled using a driving current within an electronic component, thermal degradation of the circuits within the component can be prevented. In particular, the pressure-sensitive adhesive tape of the present invention uses a heating element having a predetermined volume resistivity, so that when electricity is applied to the pressure-sensitive adhesive tape using a driving current within the electronic component, excessive temperature rise can be prevented in the electronic circuits within the component and in the connection between the circuit and the pressure-sensitive adhesive tape.

[0014] In the pressure-sensitive adhesive tape of the present invention, "the adhesive layer A melts or softens due to resistance heating" may mean that the entire adhesive layer A melts or softens due to resistance heating, or that a portion of the adhesive layer A melts or softens due to resistance heating. For example, when the adhesive layer A is a laminate as described below, "a portion of the adhesive layer A melts or softens" may mean that one or more layers constituting the laminate melt or soften.

[0015] Furthermore, when the pressure-sensitive adhesive tape of the present invention is described as "resistance heating causes the adhesive layer A to melt or soften, thereby making it possible to peel it off," it may mean that the entire adhesive layer A melts or softens due to resistance heating, making it possible to peel the adhesive layer A in the pressure-sensitive adhesive tape as a whole from the adherend; it may mean that resistance heating causes one or more layers constituting adhesive layer A to melt or soften, thereby making it possible to peel the adhesive layer A in the pressure-sensitive adhesive tape as a whole from the adherend; or it may mean that resistance heating causes one or more layers constituting adhesive layer A to melt or soften, thereby causing peeling within adhesive layer A, making it possible to peel a portion of adhesive layer A in the pressure-sensitive adhesive tape from the adherend.

[0016] The adhesive layer A "contains an adhesive" may mean that the adhesive layer A is a single layer and the adhesive is contained throughout the single layer, or that the adhesive layer A is a laminate consisting of multiple layers and the adhesive is contained in at least one of the multiple layers constituting the laminate. For example, as described below, when the adhesive layer A has two adhesive layers a (e.g., adhesive layers a1 and a2), the two adhesive layers a (e.g., adhesive layers a1 and a2) may each contain the same or different adhesives. Furthermore, when the adhesive layer A has an adhesive layer a, a heating element b, and a melt-softening layer c, the adhesive layer a may contain an adhesive, and the melt-softening layer c may also contain an adhesive. The same applies when there are two melt-softening layers c (e.g., melt-softening layers c1 and c2). Note that when the adhesive layer A is a laminate, the adhesive layers a1 and a2 constituting the adhesive layer A may be collectively referred to as adhesive layer a, and the melt-softening layers c1 and c2 may be collectively referred to as melt-softening layer c. The adhesive layer a, the heating element b, and the melt-softening layer c will be described in detail later.

[0017] <Adhesive layer A> The adhesive layer A contains at least a heating element and an adhesive, and further contains other components as necessary. The adhesive layer A has adhesive properties on both sides, and may be a single layer or may be composed of multiple layers.

[0018] The adhesive layer A having adhesive properties on both sides may mean that both sides of the adhesive layer A have pressure-sensitive adhesive properties, that both sides of the adhesive layer A have heat-adhesive properties, or that one side of the adhesive layer A has pressure-sensitive adhesive properties and the other side has heat-adhesive properties. Of these, it is preferable that both sides of the adhesive layer A have pressure-sensitive adhesive properties, because this allows the adhesive layer A to be easily adhered to an adherend or other layers constituting the pressure-sensitive adhesive tape of the present invention at room temperature and to remain firmly adhered until resistance heating is applied.

[0019] <<Heater>> The heating element is not particularly limited and can be selected from known heating elements used in resistance heating depending on the purpose, and the volume resistivity of the heating element at room temperature (20°C) is 30 μΩ·cm or more, preferably 50 μΩ·cm or more, more preferably 70 μΩ·cm or more, and particularly preferably 100 μΩ·cm or more. Although there are no particular limitations on the upper limit of the volume resistivity of the heating element, if the volume resistivity is too high, a high voltage is required when energized, so the volume resistivity is preferably 100,000 μΩ·cm or less, more preferably 20,000 μΩ·cm or less, more preferably 10,000 μΩ·cm or less, and particularly preferably 5,000 μΩ·cm or less. Specifically, the volume resistivity of the heating element can be within the range of 30 μΩ·cm to 100,000 μΩ·cm, 50 μΩ·cm to 20,000 μΩ·cm, 70 μΩ·cm to 10,000 μΩ·cm, or 100 μΩ·cm to 5,000 μΩ·cm. Here, "resistance heating" refers to a type of electrical heating method in which a current is passed through a resistive current-carrying element (heating element) and the resulting Joule heat is used to heat the current-carrying element. When a steady current is passed through a current-carrying element, the amount of Joule heat generated within a certain period of time is proportional to the square of the current magnitude and the resistance of the conductor (Joule's Law). Current-carrying elements have their own inherent resistance value (e.g., volume resistivity). By ensuring that the volume resistivity of the heating element is 30 μΩ·cm or higher, the adhesive tape can be heated alone, preventing high-temperature deterioration of the wiring circuit, for example, when the heating element is connected to the wiring circuit in an electronic device and the driving current of the electronic device is passed through the heating element during disassembly. In addition, by using a heating element having a predetermined volume resistivity, it is possible to melt or soften the adhesive layer A in a short time, thereby shortening the disassembly time. Furthermore, by using a heating element having a predetermined volume resistivity, it is possible to prevent the electronic circuit and connecting parts from being excessively heated due to the current flowing through the heating element, particularly when using a driving current within the electronic component, and to prevent thermal degradation of the electronic component.

[0020] The heating element is not particularly limited and can be selected from known heating elements depending on the purpose. Examples include metals and non-metals. Examples of metals include nichrome (108 μΩ·cm); stainless steels such as SUS 410 (62.2 μΩ·cm), SUS 304 (72.0 μΩ·cm), and SUS 430 (60.0 μΩ·cm); titanium (55.0 μΩ·cm); and nickel silver (for example, "Nickel Silver C7701" manufactured by Takeuchi Metal Foil Powder Co., Ltd. has a resistivity of 34.0 μΩ·cm). The values ​​in parentheses indicate the approximate volume resistivity of each substance at 20°C. Examples of non-metals include carbon (for example, 3,352 μΩ·cm) such as carbon nanomaterials such as graphite, graphene, graphene oxide, carbon nanotubes, graphene platelets, and carbon nanofibers. Among these, nichrome, stainless steel, and the like are preferred because they are resistant to tearing when made into a metal foil, are easy to handle as a tape, and can melt or soften the adhesive layer in a short time to significantly reduce the adhesive strength. Carbon is also preferred because it exhibits high volume resistivity, is easily formed into a thin film, and is less likely to impair the physical properties required of a tape, such as conformability. Of these, carbon nanomaterials such as carbon nanotubes are preferred because they are rod-shaped and therefore easily exhibit conductivity even in small amounts, and can melt or soften the adhesive layer A in a short time by resistance heating.

[0021] The volume resistivity of the heating element can be measured in a 20°C environment using a low resistivity meter (manufactured by Nitto Seiko Analytech Co., Ltd., product name: "Loresta-AX MCT-T370") and a four-point probe (manufactured by Nitto Seiko Analytech Co., Ltd., product name: "ASP Probe MCP-TP03P") in accordance with JIS K 7194. Measurement is performed at one point, and a resistivity correction coefficient of 4.532 is used.

[0022] The shape of the heating element is not particularly limited and can be appropriately selected depending on the purpose, as long as the heating elements are in electrical contact with each other so as to generate resistance heating. Examples include planar, mesh, particulate, and fibrous shapes. Planar shapes are preferred because they can adhere sufficiently to other layers in contact with the heating element before energization and generate heat on the surface when energized, making the heating element itself less susceptible to breakdown or disconnection during electrolysis. Examples of planar heating elements include metal foils made of the metals, nonmetallic sheets, resin sheets in which particles or fibers made of the metal or nonmetal are densely dispersed, metal or nonmetallic coatings, sheets in which nonwoven fabrics are impregnated with the metal or nonmetal, and metal or nonmetallic nonwoven fabrics. Among these planar heating elements, metal foils, nonmetallic sheets, metal or nonmetallic coatings, and metal or nonmetallic nonwoven fabrics are more preferred because they have high volume resistivity, allowing heating of the entire surface and being less susceptible to disconnection, with metal foil being even more preferred.

[0023] The planar heating element may cover the entire adhesive layer in a plan view of the adhesive tape, or may cover only a portion of the adhesive layer. The planar heating element may also be molded into a pattern, or may be strip-shaped or linear (see also FIG. 1D described below). A strip-shaped or linear heating element is advantageous in that it provides high heat generation efficiency and has a small contact area with the adherend, making it easy to peel. In this case, the length of the heating element in the minor axis direction (strip width or linear width) is preferably 0.5 mm to 20 mm, more preferably 1 mm to 10 mm, and even more preferably 2 mm to 5 mm.

[0024] When the planar heating element is patterned (has a pattern shape), the distance between the terminals (terminals for connecting to a power source) of the heating element can be increased, thereby increasing the resistance. This increases the heat generation efficiency of the planar heating element, and the pressure-sensitive adhesive tape of the present invention can be peeled off in a short time. When the planar heating element is patterned, the line width of the pattern is not particularly limited, but can be the same as the preferred range of the band width or line width.

[0025] In a planar heating element, the heating element may be disposed on one or both sides of the substrate. When the heating element is disposed on one or both sides of the substrate, the heating element may be disposed so as to cover the entire area of ​​one or both sides of the substrate, or may be disposed in a linear, strip, or pattern. When the planar heating element is disposed on one or both sides of the substrate, the heating element is disposed so as to be in direct contact with one or both sides of the substrate. The substrate is not particularly limited as long as it can support the heating element, but a resin film is preferably used from the viewpoints of adhesive tape conformability and thinning. Examples of the resin film that can be used include general-purpose films such as polyester resin films such as polyethylene terephthalate (PET) film and polyethylene naphthalate (PEN), imide resin films such as polyimide (PI) film, and polyolefin resin films such as polypropylene (PP). The resin film may also be a resin film used in the melt-softening layer described below.

[0026] Examples of the mesh-shaped heating element include a planar heating element having a plurality of through holes, a mesh-shaped or lattice-shaped heating element, and an integrally molded heating element.

[0027] The shape of the heating elements may be any shape, as long as they are electrically contactable with each other, even if they are not integrally molded. For example, they may be particles or fibers made of the metal or non-metal. Particulate or fibrous heating elements may be dispersed in the adhesive, thereby forming electrical contact between the heating elements even if they are not integrally molded. When particulate or fibrous heating elements are dispersed in the adhesive, the content of the particles or fibers is not particularly limited and can be appropriately selected depending on the purpose, as long as electrical contact between the heating elements is formed. However, the content is preferably 20% to 95% by mass, more preferably 40% to 90% by mass, relative to the total amount of the adhesive. When adhesive layer A is a single layer formed by adhesive and the heating element is contained in the single layer, the content of the particles or fibers can be defined as the content relative to the total amount of adhesive layer A. When adhesive layer A is a laminate, and one of the layers constituting the laminate has adhesive layer A in which particles or fibers of the heating element are dispersed, the content of the particles or fibers can be defined as the content relative to the total amount of one adhesive layer A.

[0028] The average thickness of the planar heating element is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 μm to 200 μm, more preferably 2 μm to 200 μm, more preferably 3 μm to 150 μm, more preferably 5 μm to 150 μm, more preferably 5 μm to 100 μm, even more preferably 10 μm to 100 μm, and preferably 10 μm to 50 μm. The average thickness of the planar heating element is the average value obtained by measuring the thickness at five or more arbitrarily selected locations. As the average thickness of the planar heating element increases, the amount of current flowing and the amount of heat generated increase, but the thickness is limited from the perspective of the adhesive tape's trackability and application workability. In contrast, when the average thickness of the planar heating element is within the above-mentioned range, a sufficient amount of current and amount of heat generated can be obtained, allowing the heating element to be efficiently heated by resistance heating, and excellent adhesive tape trackability and application workability can be achieved.

[0029] In addition, when the planar heating element is arranged on one or both sides of the substrate, the average thickness of the planar heating element refers to the thickness excluding the resin film, and when the heating element is formed on both sides of the resin film, it refers to the thickness of the heating element on each side.

[0030] The heating element may be an appropriately manufactured one or a commercially available product. The commercially available product is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include planar heating elements such as nichrome foil such as nichrome NCH1-H, stainless steel foil such as stainless steel SUS304-H and stainless steel SUS430-H, titanium foil such as titanium type 1 TR270C-H, and nickel silver such as nickel silver C7701 (all manufactured by Takeuchi Metal Foil and Powder Co., Ltd.). Pattern-molded versions of these can also be used.

[0031] <<Adhesive>> The adhesive is not particularly limited and can be selected appropriately depending on the purpose, but is preferably at least one of a pressure-sensitive adhesive and a hot-melt adhesive. By using a hot-melt adhesive or a pressure-sensitive adhesive containing a thermoplastic resin as the adhesive contained in adhesive layer A, the resin can be melted or softened by the heat generated by passing an electric current, which is advantageous in that peeling is possible without the need to mix in components that cause peeling initiation points at the adhesive interface or components that cause a decrease in adhesive strength, such as a heat-foaming agent. Furthermore, the adhesive preferably has a softening point, which is advantageous in that it rapidly becomes flexible when heated above the softening point, thereby exhibiting high deformability and fluidity.

[0032] When heated, the resin of the adhesive melts or softens, and the adhesive strength during heating decreases compared to the adhesive strength at room temperature.

[0033] The storage modulus G of the adhesive (adhesive layer formed by the adhesive) measured by dynamic viscoelasticity spectrum at 1 Hz and 23°C 23 From the viewpoint of securing the adherends well together under normal conditions, the adhesive strength is set to 1.0 x 10 3Pa~1.0×10 9 Pa is preferred, and 1.0×10 3 Pa ~ 5.0 × 10 7 Pa is preferred, 5.0 x 10 3 Pa ~ 5.0 × 10 7 Pa is more preferred, 5.0 × 10 3 Pa ~ 5.0 × 10 6 Pa is more preferable, and 5.0×10 3 Pa~1.0×10 6 Pa is particularly preferred.

[0034] In particular, when the adhesive is a pressure-sensitive adhesive (adhesive), the storage modulus G of the pressure-sensitive adhesive (pressure-sensitive adhesive layer) measured by dynamic viscoelasticity spectroscopy at 1 Hz and 23°C is 23 From the viewpoint of properly fixing the adherends together in a normal state (a state where resistance heating is not performed), the storage modulus G 23 Within the range of 1.0×10 3 Pa ~ 5.0 × 10 7 Pa is preferred, 5.0 x 10 3 Pa ~ 5.0 × 10 6 Pa is more preferred, 5.0 × 10 3 Pa~1.0×10 6 Pa is more preferred.

[0035] In addition, when the adhesive is a hot melt adhesive, the storage modulus G of the hot melt adhesive (hot melt adhesive layer) measured by a dynamic viscoelastic spectrum at 1 Hz and 23°C 23 From the viewpoint of securing the adherends well together under normal conditions (when not resistance heated), the 3 Pa~1.0×10 9 Pa is preferred, 5.0 x 10 3 Pa ~ 5.0 × 10 8 Pa is more preferable, and 1.0 × 10 4 Pa~1.0×10 8 Pa is more preferred.

[0036] The storage modulus G of the adhesive (the adhesive layer formed by the adhesive) measured by a dynamic viscoelastic spectrum at 1 Hz and 100 ° C. 100 From the viewpoint of easily separating the adherends by resistance heating, the 0 Pa ~ 5.0 × 10 6 Pa is preferred, 1.0 x 10 3 Pa~1.0×10 6 Pa is preferred, 1.0 x 10 3 Pa~1.0×10 6 Pa is more preferred, 5.0 × 10 3 Pa ~ 5.0 × 10 5 Pa is more preferred.

[0037] In particular, when the adhesive is a pressure-sensitive adhesive (adhesive), the storage modulus G of the pressure-sensitive adhesive (pressure-sensitive adhesive layer) measured by dynamic viscoelasticity spectroscopy at 1 Hz and 100°C is 100 As the storage modulus G 100 Within the range of 1.0×10 2 Pa ~ 5.0 × 10 6 Pa range is preferred, and 1.0 × 10 3 Pa~1.0×10 6 Pa, more preferably in the range of 5.0 × 10 3 Pa ~ 5.0 × 10 5 The storage modulus of the pressure-sensitive adhesive (adhesive layer formed by the pressure-sensitive adhesive) is more preferably in the range of Pa. G100 By keeping the resistance heating temperature within the above range, the pressure-sensitive adhesive can be melted or softened in a short time by resistance heating and become peelable, even when a low current is used.

[0038] When the adhesive is a pressure-sensitive adhesive, the storage modulus G 23 , and storage modulus G 100can be measured by the following method. Using a viscoelasticity tester (ARES-G2, manufactured by TA Instruments Japan), a test specimen was sandwiched between parallel disks with a diameter of 8 mm, which are the measuring section of the tester, and the storage modulus G' was measured under conditions of a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a heating rate of 2°C / min, and the values ​​at 23°C and 100°C were recorded. The test specimens used had a pressure-sensitive adhesive layer (adhesive layer) formed by applying a pressure-sensitive adhesive to a dry thickness of approximately 2 mm using an applicator, drying, and curing as necessary.

[0039] In addition, when the adhesive is a hot melt adhesive, the storage modulus G 23 , and storage modulus G 100 The test piece was sandwiched between the tensile measurement jigs, which are the measuring part of the viscoelasticity tester, and the storage modulus G' was measured under conditions of a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a heating rate of 2°C / min, and the values ​​were recorded as the values ​​at 23°C and 100°C. The test piece was coated with hot melt adhesive using an applicator so that the thickness after drying was approximately 0.1 mm, and then dried, and cured as necessary to form a hot melt adhesive layer.

[0040] The temperature at which the loss tangent (tan δ) of the adhesive (the adhesive layer formed by the adhesive) is 0.45 or greater is preferably in the temperature range of 80°C or greater and 200°C or less, more preferably the temperature at which the tan δ is 0.8 or greater is in the temperature range of 80°C or greater and 200°C or less, and even more preferably the temperature at which the tan δ is 1.0 or greater is in the temperature range of 80°C or greater and 200°C or less.

[0041] The temperature at which the tan δ of the adhesive (the adhesive layer formed by the adhesive) is equal to or greater than a predetermined value is in the temperature range of 80°C or higher and 200°C or lower, which is advantageous in that when the adhesive reaches that temperature due to heat received from a heating element, plastic deformation is likely to occur due to melting or softening, and cohesive failure occurs within the layer formed by the adhesive, making it easier to peel and disassemble in a shorter time. As will be described later, when adhesive layer A has adhesive layer a1 and adhesive layer a2, it is preferable that the temperature at which at least one of adhesive layers a1 and a2 has a loss tangent (tan δ) of 0.45 or higher is in the temperature range of 80°C or higher and 200°C or lower.

[0042] The loss tangent (tanδ) is calculated from the storage modulus (G') and loss modulus (G") obtained by dynamic viscoelasticity measurement using temperature dispersion, using the formula tanδ=G" / G'. 23 and storage modulus G 100 The measurement method is the same as that of

[0043] Storage modulus G of the adhesive (adhesive layer formed using the adhesive) 23 , storage modulus G 100 The loss tangent (tanδ) and the loss tangent (tanδ) can be adjusted by adjusting the type and combination of monomers constituting the resin (base polymer) that is the main component of the adhesive, the compounding ratio of each monomer, the compounding amount of tackifying resin added as needed, the compounding amount (gel fraction) of crosslinking agent added as needed, etc. The resin (base polymer) that is the main component of the adhesive may be used alone or in combination of two or more types. The resin that is the main component of the adhesive will be explained in the "-Resin-" section below. In addition, when the adhesive layer contains a heating element, the storage modulus G of the adhesive layer 23 , storage modulus G 100 The loss tangent (tan δ) and the heat dissipation factor (H) are the values ​​for the adhesive (adhesive layer) excluding the heating element.

[0044] The adhesive preferably has a melting point of 70°C or higher and 150°C or lower, more preferably 75°C or higher and 130°C or lower, and even more preferably 80°C or higher and 110°C or lower. By setting the melting point of the adhesive within this range, high adhesive strength can be exhibited before current is applied, and the adhesive can be easily melted or softened even with a small amount of resistance heating due to current application. The melting point of the adhesive can be adjusted by selecting the type of resin that is the main component of the adhesive, the content of the tackifier resin in the adhesive, the gel fraction, etc. The melting point of the adhesive can be the temperature of the endothermic peak associated with melting measured using differential scanning calorimetry (DSC).

[0045] <<<Pressure-sensitive adhesive>>> The pressure-sensitive adhesive is an adhesive that bonds by applying pressure for a short time at room temperature. Pressure-sensitive adhesives are also called pressure-sensitive agents. The pressure-sensitive adhesive has tackiness at room temperature. There are no particular limitations on the pressure-sensitive adhesive, and any known pressure-sensitive adhesive can be appropriately selected depending on the purpose. Examples include acrylic pressure-sensitive adhesives (acrylic pressure-sensitive adhesives), urethane pressure-sensitive adhesives (urethane pressure-sensitive adhesives), rubber-based pressure-sensitive adhesives (rubber-based pressure-sensitive adhesives) such as synthetic rubber pressure-sensitive adhesives and natural rubber pressure-sensitive adhesives, and silicone pressure-sensitive adhesives (silicone pressure-sensitive adhesives).

[0046] The pressure-sensitive adhesive may be in an embodiment containing a thermoplastic resin, or in an embodiment containing a resin that does not contain a thermoplastic resin and has no thermoplastic properties. When the pressure-sensitive adhesive is in an embodiment containing a thermoplastic resin, the pressure-sensitive adhesive melts or softens due to resistance heating, reducing the adhesive strength of the pressure-sensitive adhesive and making the adhesive layer A peelable. When the pressure-sensitive adhesive is in an embodiment containing a resin that does not contain a thermoplastic resin and has no thermoplastic properties, by using the pressure-sensitive adhesive in combination with at least one of the hot-melt adhesive and the melt-softening layer, the hot-melt adhesive or the melt-softening layer melts due to resistance heating, making the adhesive layer A peelable.

[0047] The acrylic pressure-sensitive adhesive contains an acrylic resin and, if necessary, further contains other components such as a tackifier resin, a crosslinker, and an antioxidant. The urethane pressure-sensitive adhesive contains a urethane resin and, if necessary, further contains other components such as a tackifier resin, a crosslinker, and an antioxidant. The rubber pressure-sensitive adhesive contains a rubber material such as a styrene resin and, if necessary, further contains other components such as a tackifier resin, a crosslinker, and an antioxidant. The silicone pressure-sensitive adhesive contains a silicone resin and, if necessary, further contains other components such as a tackifier resin, a crosslinker, and an antioxidant.

[0048] <<<Hot melt adhesive>>> The hot melt adhesive is a thermoplastic adhesive that is solid at room temperature but is liquefied by heating and melting, applied to an adherend, and then cooled and solidified to form a bond. The hot melt adhesive is dissolved in a solvent, applied, and dried to solidify to form a film, and a bonded state can be formed by applying heat when bonding to an adherend. The hot melt adhesive typically has no tackiness at room temperature or has lower tackiness than a pressure-sensitive adhesive. The hot melt adhesive contains a thermoplastic resin and, if necessary, further contains other components such as a tackifier resin, a crosslinking agent, and an antioxidant.

[0049] Examples of the hot melt adhesive include ethylene-vinyl acetate copolymer (EVA)-based hot melt adhesives, polyolefin-based hot melt adhesives, polyamide-based hot melt adhesives, polyurethane-based hot melt adhesives, acrylic-based hot melt adhesives, polyester-based hot melt adhesives, and rubber-based hot melt adhesives based on styrene-based thermoplastic elastomers.

[0050] -resin- Examples of resins (base polymers) that can be used as the main component of the pressure-sensitive adhesive and the hot melt adhesive include urethane resins such as polyurethane (PU) and thermoplastic polyurethane (TPU); polycarbonate (PC); vinyl chloride resins such as polyvinyl chloride (PVC) and vinyl chloride-vinyl acetate copolymer resin; acrylic resins such as polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate (PMMA), polyethyl methacrylate, and acrylic polymers obtained by polymerizing one or more (meth)acrylic monomers; polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate; polyamide resins such as Nylon (registered trademark); Examples of suitable thermoplastic elastomers include polystyrene resins such as polystyrene (PS), imide-modified polystyrene, acrylonitrile-butadiene-styrene (ABS) resin, imide-modified ABS resin, styrene-acrylonitrile copolymer (SAN) resin, and acrylonitrile-ethylene-propylene-diene-styrene (AES) resin; olefin resins such as polyethylene (PE) resin, polypropylene (PP) resin, and cycloolefin resin; cellulose resins such as nitrocellulose and cellulose acetate; silicone resins; thermoplastic resins such as fluorine-based resins; and thermoplastic elastomers such as styrene thermoplastic elastomers, olefin thermoplastic elastomers, vinyl chloride thermoplastic elastomers, acrylic thermoplastic elastomers, urethane thermoplastic elastomers, ester thermoplastic elastomers, and amide thermoplastic elastomers. These may be used alone or in combination of two or more.

[0051] Among these, thermoplastic resins are preferred, and thermoplastic elastomers such as acrylic resins, urethane resins, polyester resins, styrene thermoplastic elastomers, olefin thermoplastic elastomers, vinyl chloride thermoplastic elastomers, acrylic thermoplastic elastomers, ester thermoplastic elastomer thermoplastic elastomers, urethane thermoplastic elastomers, and amide thermoplastic elastomers are more preferred, with styrene thermoplastic elastomers being particularly preferred.

[0052] Examples of the styrene thermoplastic elastomer include styrene-based AB diblock copolymers such as styrene-ethylene-butylene copolymer (SEB); styrene-butadiene-styrene copolymer (SBS), hydrogenated SBS (styrene-ethylene-butylene-styrene copolymer (SEBS)), styrene-isoprene-styrene copolymer (SIS), hydrogenated SIS (styrene-ethylene-propylene-styrene copolymer (SEPS)), and styrene-isobutylene-styrene copolymer (SIBS); styrene-based ABAB tetrablock copolymers such as styrene-butadiene-styrene-butadiene (SBSB); styrene-based ABABA pentablock copolymers such as styrene-butadiene-styrene-butadiene-styrene (SBSBS); styrene-based multiblock copolymers having AB repeating units of any of the above; and hydrogenated styrene-based random copolymers such as styrene-butadiene rubber (SBR) in which the ethylenic double bonds have been hydrogenated. These may be used alone or in combination of two or more. As the styrene-based thermoplastic elastomer, commercially available products may be used.

[0053] The weight-average molecular weight of the thermoplastic elastomer is preferably in the range of 10,000 to 800,000, more preferably in the range of 30,000 to 500,000, and even more preferably in the range of 50,000 to 300,000. By adjusting it to the above range, it is easy to adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to within the desired range, and it becomes easy to melt or soften the adhesive by resistance heating. The method for measuring the weight-average molecular weight can be the same as the method for measuring the weight-average molecular weight of an acrylic polymer described below.

[0054] The thermoplastic elastomer may be one or more triblock copolymers, one or more diblock copolymers, or a mixture of a triblock copolymer and a diblock copolymer. Among these, it is preferable that the thermoplastic elastomer contain at least a diblock copolymer, because the adhesive exhibits moderate cohesive strength, has good adhesive strength at room temperature before application of current, and can be easily melted or softened by resistance heating after application of current. The content of the diblock copolymer in the thermoplastic elastomer is preferably in the range of 10% to 100% by mass, more preferably in the range of 10% to 90% by mass, more preferably in the range of 15% to 80% by mass, and even more preferably in the range of 20% to 75% by mass, because this provides an excellent balance between adhesiveness at room temperature and melting or softening by resistance heating.

[0055] The thermoplastic resin that is the main component of the adhesive is preferably a polyester resin, and may be a crystalline polyester resin or a non-crystalline polyester resin.

[0056] Furthermore, the thermoplastic resin that is the main component of the adhesive is preferably an acrylic resin. As the acrylic resin, an acrylic polymer obtained by polymerizing a monomer component containing a (meth)acrylic acid ester monomer can be used. The acrylic polymer may be a homopolymer of a (meth)acrylic acid ester monomer, or a copolymer of a (meth)acrylic acid ester monomer and another monomer. Among these, a copolymer is preferable. Note that (meth)acrylic means acrylic or methacrylic. (Meth)acrylate means acrylate or methacrylate.

[0057] Examples of the (meth)acrylic acid ester monomer that constitutes the acrylic polymer include (meth)acrylic acid ester monomers having 1 to 14 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, and lauryl (meth)acrylate. Among these, it is preferable to contain a (meth)acrylic acid alkyl ester monomer having an alkyl chain containing 1 to 9 carbon atoms, more preferably a (meth)acrylic acid alkyl ester monomer having an alkyl chain containing 2 to 9 carbon atoms, and even more preferable to contain a (meth)acrylic acid alkyl ester monomer having an alkyl chain containing 4 to 9 carbon atoms, since this makes it easier to adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired ranges. Examples of the acrylic acid alkyl ester monomer having an alkyl chain containing 4 to 9 carbon atoms include n-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, and isononyl acrylate. It is preferable that the acrylic polymer contains one or more structural units selected from the group consisting of these.

[0058] The content of the (meth)acrylic acid ester monomer is preferably in the range of 70 to 99.9 mass % of the total amount of monomer components constituting the acrylic polymer, more preferably in the range of 80 to 99 mass %, and even more preferably in the range of 90 to 97 mass %, since this makes it easier to adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired ranges.

[0059] The acrylic polymer preferably contains, as a (meth)acrylic monomer, a (meth)acrylic monomer having a polar group as a constituent unit in addition to the (meth)acrylic acid ester monomer described above. Examples of the polar group include a hydroxyl group, a carboxyl group, an amide group, and polar groups other than these groups.

[0060] Examples of the (meth)acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, hydroxypropyl (meth)acrylate, caprolactone-modified (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, etc. Among these, it is preferable to use 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate.

[0061] Examples of the (meth)acrylic monomer having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, a dimer of acrylic acid or methacrylic acid, ethylene oxide-modified succinic acid acrylate, etc. Among these, it is preferable to use acrylic acid.

[0062] Examples of the (meth)acrylic monomer having an amide group include N-vinyl-2-pyrrolidone, N-vinylcaprolactam, acryloylmorpholine, acrylamide, N,N-dimethylacrylamide, 2-(perhydrophthalimide-N-yl)ethyl acrylate, etc. Among these, it is preferable to use N-vinyl-2-pyrrolidone, N-vinylcaprolactam, and acryloylmorpholine.

[0063] Examples of the vinyl monomer having another polar group include vinyl acetate, acrylonitrile, maleic anhydride, and itaconic anhydride.

[0064] Among (meth)acrylic monomers having a polar group, it is preferable to include at least one of a (meth)acrylic monomer having a hydroxyl group and a (meth)acrylic monomer having a carboxyl group, because when a crosslinking agent described below is used in combination, a crosslinked structure can be formed between the hydroxyl group or carboxyl group and the crosslinking agent, making it possible to adjust the storage modulus of the adhesive (adhesive layer).

[0065] The content of the (meth)acrylic monomer having a polar group is preferably in the range of 0.1% by mass to 20% by mass, more preferably in the range of 1% by mass to 13% by mass, and more preferably in the range of 1.5% by mass to 8% by mass, because this makes it easier to adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired ranges.

[0066] The acrylic polymer preferably has a weight-average molecular weight of 400,000 to 1,400,000, more preferably 600,000 to 1,200,000, and more preferably 650,000 to 1,100,000, since this makes it easier to adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired ranges.

[0067] The weight-average molecular weight can be measured by gel permeation chromatography (GPC). More specifically, the weight-average molecular weight can be determined in terms of polystyrene using a GPC measuring device "SC8020" manufactured by Tosoh Corporation under the following GPC measuring conditions: (GPC measurement conditions) Sample concentration: 0.5% by mass (tetrahydrofuran solution) Sample injection volume: 100 μL Eluent: tetrahydrofuran (THF) ·Flow rate: 1.0mL / min Column temperature (measurement temperature): 40℃ Column: Tosoh Corporation "TSKgel GMHHR-H" Detector: Differential refraction

[0068] The content of the resin, which is the main component of the adhesive, is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more, based on 100% by mass of the total solid content of the adhesive. Note that, when the adhesive contains the above-mentioned heat generating element, this refers to the content ratio of the total solid content of the adhesive excluding the content of the heat generating element.

[0069] Furthermore, when the adhesive contains a tackifier resin described below in addition to the resin as the main component, the total content of the resin as the main component and the tackifier resin is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more, based on 100% by mass of the total solid content of the adhesive. When the adhesive contains the above-mentioned heat-generating element, the content means the content ratio of the total solid content of the adhesive excluding the content of the heat-generating element.

[0070] -Other ingredients- Examples of other components that can be used in the pressure-sensitive adhesive and hot melt adhesive include tackifier resins, crosslinking agents, antioxidants, thermally expandable fillers, solvents, infrared absorbers, ultraviolet absorbers, fillers; glass or plastic fibers; fillers such as balloons, beads, and metal powders; pigments, thickeners, etc.

[0071] The adhesive and the adhesive layer formed using the adhesive may be thermally foamable, capable of foaming and / or expanding upon heating. However, they are preferably non-foamable, meaning they do not foam and / or expand upon heating. Even if the adhesive does not contain components that foam and / or expand within the adhesive layer (expansion-inducing components), such as thermally expandable fillers or foaming agents, the resin contained in the adhesive melts or softens, making it possible to separate the adhesive. Furthermore, the non-foamable adhesive layer can prevent damage to articles or parts due to gas generated by foaming, and damage to articles or parts due to pressure generated by expansion pressing against the adherend. Furthermore, if the adhesive layer is thermally foamable, after long-term use in articles or parts, the foaming agent may denature, deactivate, or be released to the outside, preventing foaming during disassembly. However, the non-foamable adhesive layer ensures reliable disassembly even after long-term use in articles or parts. The term "an adhesive (adhesive layer) that does not contain a foaming and / or expanding component (expansion-inducing component)" refers to the adhesive (adhesive layer) containing less than 1 part by mass per 100 parts by mass of the base polymer.

[0072] --Tackifying resin-- In the adhesive, a tackifying resin may be used to adjust the adhesive strength of the resulting adhesive layer. The tackifying resin is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include rosin-based tackifying resins, polymerized rosin-based tackifying resins, polymerized rosin ester-based tackifying resins, rosin phenol-based tackifying resins, stabilized rosin ester-based tackifying resins, disproportionated rosin ester-based tackifying resins, hydrogenated rosin ester-based tackifying resins, terpene-based tackifying resins, terpene phenol-based tackifying resins, aliphatic (petroleum resin)-based tackifying resins, C5-based / C9-based petroleum-based tackifying resins, and (meth)acrylate-based tackifying resins.

[0073] In addition to the tackifier resins described above, tackifier resins that are liquid at room temperature can also be used, such as process oil, polyester-based tackifier resins, and low-molecular-weight liquid rubbers such as polybutene.

[0074] The content of the tackifier resin in the adhesive is preferably in the range of 1 to 150 parts by mass per 100 parts by mass of the base polymer, since this improves the adhesive properties of the adhesive at room temperature and enables it to exhibit thermal durability. Of these, the range of 10 to 150 parts by mass is more preferred, the range of 15 to 100 parts by mass is more preferred, and the range of 50 to 100 parts by mass is even more preferred.

[0075] --Crosslinking agent-- A crosslinking agent may be used in the adhesive to improve the cohesive strength of the resulting adhesive layer. The crosslinking agent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, polyvalent metal salt-based crosslinking agents, metal chelate-based crosslinking agents, ketohydrazide-based crosslinking agents, oxazoline-based crosslinking agents, carbodiimide-based crosslinking agents, silane-based crosslinking agents, and glycidyl(alkoxy)epoxysilane-based crosslinking agents.

[0076] The content of the crosslinking agent contained in the adhesive can be set appropriately so that the adhesive has a gel fraction in the range described below.

[0077] --Antioxidants-- The antioxidant is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include phenol-based antioxidants, amine-based antioxidants, and carbodiimide-based antioxidants.

[0078] --solvent-- The solvent is not particularly limited and can be selected appropriately from solvents commonly used in adhesive compositions depending on the purpose, and examples thereof include organic solvents such as toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, and hexane; water; and aqueous solvents mainly containing water. Note that the adhesive layer A usually does not contain a solvent, but may contain residual solvent.

[0079] -glue- When the adhesive contains the resin and crosslinking agent as the main components described above, the gel fraction of the adhesive is preferably 0% to 80% by mass, because the adhesive can be sufficiently melted and / or softened by resistance heating caused by short-term current application to the heating element, even if the time for applying current to the heating element is short. Within the above-mentioned range, the gel fraction is more preferably 10% to 65% by mass, and even more preferably 15% to 55% by mass, because this improves the initial tackiness of the adhesive layer and allows the adhesive to exhibit good holding power even in high-temperature environments. The above gel fraction range is particularly preferred when the adhesive is a pressure-sensitive adhesive. Meanwhile, the gel fraction is more preferably 0% to 60% by mass, and even more preferably 0% to 40% by mass, because this improves ease of dismantling by heating. The above gel fraction range is particularly preferred when the adhesive is a hot-melt adhesive.

[0080] The gel fraction of the adhesive is determined by forming a coating film of the adhesive, immersing the coating film in toluene, and leaving it for 24 hours, measuring the mass of the remaining insoluble matter after drying, and expressing it as a percentage of the original mass. The gel fraction of the adhesive can be adjusted by the amount of crosslinking agent, etc.

[0081] [Layer structure of adhesive layer A] The adhesive layer A in the pressure-sensitive adhesive tape is a layer having adhesiveness on both sides thereof, and may be a single layer or may be composed of multiple layers. It is preferable that both sides of the adhesive layer A have pressure-sensitive adhesiveness and / or heat-adhesiveness.

[0082] [First aspect] When the adhesive layer A is composed of multiple layers, the pressure-sensitive adhesive tape 10 of the present invention may include, for example, an adhesive layer A as a laminate having a planar heating element b and an adhesive layer a1 and an adhesive layer a2 on each side of the heating element, laminated in the order of adhesive layer a1 / heating element b / adhesive layer a2, as shown in Figures 1A and 1B. That is, the adhesive layer A of the first embodiment is a laminate having a heating element b, an adhesive layer a1 in contact with one side of the heating element b, and an adhesive layer a2 in contact with the other side of the heating element b. The adhesive layer a1 and the adhesive layer a2 may have the same composition or different compositions. At least one of the adhesive layer a1 and the adhesive layer a2 may be softened or melted by heating, and both the adhesive layer a1 and the adhesive layer a2 may be softened or melted by heating. At least one of the adhesive layer a1 and the adhesive layer a2 in contact with the heating element b melts or softens by resistance heating, reducing the adhesive strength and making the adhesive layer A peelable.

[0083] In particular, it is preferable that the adhesive layers a1 and a2 have different compositions. By forming the adhesive layers a1 and a2 from different adhesives, the tendency of the storage modulus and loss tangent (tan δ) can be changed, and even if both the adhesive layers a1 and a2 can be softened or melted by heating, it is advantageous in that it becomes possible to adjust the temperature and peel position during disassembly due to the difference in the physical properties of the adhesive layers a1 and a2.

[0084] In the adhesive layer A of the first embodiment, the details of the adhesive that forms the adhesive layer a can be the same as those explained in the above section "<<Adhesive>>".

[0085] At least one of the adhesive layers a1 and a2 is preferably a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive, and more preferably both of the adhesive layers a1 and a2 are pressure-sensitive adhesive layers. Because the pressure-sensitive adhesive layer has tackiness at room temperature, the adhesive layer a1 and / or adhesive layer a2, which is a pressure-sensitive adhesive layer, can be easily attached and bonded to other layers constituting the pressure-sensitive tape or to an adherend at room temperature.

[0086] At least one of the adhesive layers a1 and a2 may be a hot melt adhesive layer formed of a hot melt adhesive, or both of the adhesive layers a1 and a2 may be hot melt adhesive layers. Since a hot melt adhesive exhibits adhesive properties when heated, the adhesive layer a1 and / or adhesive layer a2, which are hot melt adhesive layers, can be easily attached and bonded to other layers constituting the pressure-sensitive adhesive tape or to an adherend by heating.

[0087] Alternatively, one of the adhesive layers a1 and a2 may be a pressure-sensitive adhesive layer, and the other may be a hot-melt adhesive layer.

[0088] In the adhesive layer A of the first embodiment, it is preferable that the planar heating element b has a pair of extension portions e that extend and are exposed from the outer peripheries of the adhesive layer a1 and the adhesive layer a2 in a planar view (see FIGS. 1C and 1D). The extension portions e may be provided in two or more independent locations, and their positions on the heating element are not particularly limited and can be selected appropriately depending on the purpose. The two extension portions e may be located on the same side of the outer peripheries of the adhesive layers a1 and a2 (see FIGS. 1D(1) to (3)), or on two different sides (see FIGS. 1C and 1D(4) to (6)).

[0089] The extensions e are preferably located on two opposing sides of the outer periphery of the adhesive layers a1 and a2 (see FIGS. 1D(4) to (6)), and preferably on diagonal lines of the outer periphery of the adhesive layers a1 and a2 (see FIGS. 1D(2) to (7)). This allows current to flow throughout the entire area of ​​the planar heating element b, further improving heating efficiency. Furthermore, when the extensions e are located on the same side of the outer periphery of the adhesive layers a1 and a2, it is preferable that the heating element b has a U-shape, zigzag shape, or the like in plan view (see FIGS. 1D(1) to (4) and (8)). However, the extensions e may be located in adjacent parts of the same side as long as the heating element can uniformly heat the surfaces of the adhesive layers a1 and a2 (see FIGS. 1D(3) and (8)). This allows current to flow throughout the entire area of ​​the planar heating element b, further improving heating efficiency.

[0090] The extensions e may be provided in three or more locations (see FIG. 1D(9)), and a desired pair (two locations) may be selected appropriately to energize the heating element. The pair of extensions e of the heating element b functions as a pair of terminals for electrically connecting to a power source in the article dismantling method described below, making it possible to easily energize the heating element b.

[0091] The length of the extension portion is preferably 1 mm to 50 mm, more preferably 2 mm to 25 mm, from the viewpoint of facilitating contact with a power source. Each extension portion may be bent in a direction different from the surface direction of the adhesive tape. For example, when the adherends are bonded together, the extension portion may be folded in a direction perpendicular to the surface direction of the adhesive tape and stored, and when the bond between the adherends is to be released (during disassembly), the extension portion may be folded again in the surface direction to bring the extension portion into contact with the power source.

[0092] When the adhesive layer A is a laminate composed of multiple layers, the average thickness of each of the adhesive layers a1 and a2 is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 μm to 200 μm, more preferably 10 μm to 150 μm, and even more preferably 20 μm to 100 μm. The average thickness of each of the adhesive layers a1 and a2 in the second embodiment described below can be similarly specified. When the adhesive layer A is a laminate composed of multiple layers, the total thickness of the adhesive layer A is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 15 μm to 500 μm, more preferably 30 μm to 400 μm, and even more preferably 50 μm to 300 μm. The total thickness of the adhesive layer A in the second embodiment described below can be similarly specified.

[0093] [Second aspect] 2, the pressure-sensitive adhesive tape 20 of the present invention may include an adhesive layer A that is a laminate formed by laminating adhesive layer a1 / heat generating element b / melt-softening layer c / adhesive layer a2 in this order. Alternatively, the adhesive layer A may be a laminate formed by laminating adhesive layer a1 / melt-softening layer c / heat generating element b / adhesive layer a2 in this order; or a laminate formed by laminating adhesive layer a1 / melt-softening layer c1 / heat generating element b / melt-softening layer c2 / adhesive layer a2 in this order. Furthermore, the adhesive layer A may be a laminate formed by laminating adhesive layer a / heat generating element b / melt-softening layer c in this order.

[0094] That is, the adhesive layer A of the second embodiment has a heating element, one or more adhesive layers a, and one or more melt-softening layers c. One example of the adhesive layer A of the second embodiment is a laminate having a heating element b, an adhesive layer a arranged on one side of the heating element b, and a melt-softening layer c arranged on the other side of the heating element b. Another example of the adhesive layer A of the second embodiment is a laminate having a heating element b, an adhesive layer a1 arranged on one side of the heating element b, an adhesive layer a2 arranged on the other side of the heating element b, and a melt-softening layer c arranged at least either between the heating element b and the adhesive layer a1 or between the heating element b and the adhesive layer a2.

[0095] At least the melt-softening layer c of the adhesive layer A melts or softens by resistance heating, making the adhesive layer A peelable. In this case, each of the adhesive layers a1 and a2 may contain an adhesive that melts or softens by resistance heating, or may not contain an adhesive that melts or softens by resistance heating. Furthermore, the adhesive layers a1 and a2 may have the same composition as each other, or may have different compositions. In plan view, it is preferable that the planar heating element b has a pair of extension portions that extend and are exposed from the outer peripheries of the adhesive layers a1 and a2 and the melt-softening layer c. Details of the extension portions are the same as those of the extension portions of the planar heating element b in the adhesive layer A of the first embodiment described above.

[0096] <<Adhesive layer a>> In the adhesive layer A of the second embodiment, the adhesive layer a is preferably formed of a pressure-sensitive adhesive or a hot-melt adhesive. Details of the adhesive that forms the adhesive layer a can be the same as those described above in the "<<Adhesive>>" section.

[0097] In the adhesive layer A of the second embodiment, since the melt-softening layer is a layer that melts or softens when heated, the adhesive layer a may or may not melt or soften when heated, but it is preferable that it melts or softens.

[0098] In the adhesive layer A of the second embodiment, at least one of the adhesive layers a1 and a2 is preferably a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive, and it is more preferable that both of the adhesive layers a1 and a2 are pressure-sensitive adhesive layers. Because the pressure-sensitive adhesive layer has tackiness at room temperature, the adhesive layer a1 and / or adhesive layer a2, which is a pressure-sensitive adhesive layer, can be easily attached and bonded to other layers constituting the pressure-sensitive tape or to an adherend at room temperature.

[0099] At least one of the adhesive layers a1 and a2 may be a hot melt adhesive layer formed of a hot melt adhesive, or both of the adhesive layers a1 and a2 may be hot melt adhesive layers. Since a hot melt adhesive exhibits adhesive properties when heated, the adhesive layer a1 and / or adhesive layer a2, which are hot melt adhesive layers, can be easily attached and bonded to other layers constituting the pressure-sensitive adhesive tape or to an adherend by heating.

[0100] Alternatively, one of the adhesive layers a1 and a2 may be a pressure-sensitive adhesive layer, and the other may be a hot-melt adhesive layer.

[0101] <<Melted and softened layer>> The melt-softening layer is a layer that melts or softens when heated. The melt-softening layer is not particularly limited, and can be any resin layer that melts or softens when heated, as long as it provides adhesion to the adhesive layer and the heating element and ensures the desired adhesive strength between adherends in the article described below. Examples include a thermoplastic resin film, a resin layer in which particles with a softening point lower than that of the matrix resin are dispersed in a matrix resin, and a resin layer in which particles with a softening point are dispersed in a matrix resin that has no softening point. Examples of thermoplastic resins used in the thermoplastic resin film include polyolefin resins such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), polypropylene (PP), and linear low-density polyethylene (LLDPE); ethylene copolymer resins such as ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); polyester resins such as crystalline polyester and amorphous polyester; and urethane resins. The thermoplastic resins and thermoplastic elastomers described above for adhesives can also be used.

[0102] The thermoplastic film may contain additives such as a plasticizer or a tackifier resin when it is difficult to adjust the melting or softening temperature of the resin constituting the thermoplastic film alone.

[0103] The melting / softening layer preferably has a melting point of 70°C or higher and 150°C or lower, more preferably 75°C or higher and 130°C or lower, and even more preferably 80°C or higher and 110°C or lower. By setting the melting point of the melting / softening layer within this range, it can be easily melted or softened even with a small amount of resistance heating due to electrical current application. The melting point of the melting / softening layer can be adjusted by selecting the type and composition of the resin (particularly the thermoplastic resin) that is the main component of the melting / softening layer. The melting point (melting temperature) of the melting / softening layer can be the temperature of the endothermic peak associated with melting measured using differential scanning calorimetry (DSC).

[0104] Storage modulus G measured by dynamic viscoelasticity spectrum at 1 Hz and 23°C of the melt-softened layer23 In order to ensure good fixation between adjacent layers under normal conditions, the 3 Pa~1.0×10 9 Pa is preferred, 5.0 x 10 3 Pa ~ 5.0 × 10 8 Pa is more preferable, and 1.0 × 10 4 Pa~1.0×10 8 The storage modulus G of the melt-softening layer is particularly preferably 100 Pa. 23 is the storage modulus G of the adhesive (adhesive layer) 23 It can be measured by the same method as the measurement method of (1).

[0105] The storage modulus of the melt-softened layer is 1.0×10 5 The temperature at which the storage modulus of the melt-softened layer is less than 1.0×10 Pa is preferably in the temperature range of 80°C to 200°C, and 4 It is more preferable that the temperature at which the storage modulus of the melt-softened layer is less than 1.0×10 Pa is in the temperature range of 80°C to 200°C. 3 It is more preferable that the temperature at which the storage modulus of the melt-softened layer is less than 1.0×10 Pa is in the temperature range of 80° C. to 200° C. 5 The temperature at which the storage modulus is less than Pa is in the temperature range of 80°C to 200°C, which is advantageous in that when the melt-softening layer reaches that temperature by receiving heat from the heating element, it melts or softens, causing peeling within the melt-softening layer or at the interface between this layer and an adjacent layer. The storage modulus of the melt-softening layer can be measured in the same manner as the method for measuring the storage modulus of the adhesive (adhesive layer) described above.

[0106] When the melt-softening layer is provided, the average thickness of the melt-softening layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 μm to 200 μm, more preferably 10 μm to 150 μm, and even more preferably 20 μm to 100 μm.

[0107] [Third aspect] When the adhesive layer A is a single layer, the adhesive layer A may be a single layer of adhesive layer a3, and the adhesive layer a3 may contain the heating element b (see FIG. 3). The adhesive layer a3 preferably contains at least one of the pressure-sensitive adhesive containing the thermoplastic resin and the hot-melt adhesive as the adhesive, and the adhesive layer a3 melts or softens due to resistance heating, reducing the adhesive strength and making the adhesive layer A peelable.

[0108] In the adhesive layer A of the third embodiment, the adhesive forming the adhesive layer a3 may be a pressure-sensitive adhesive. That is, the adhesive layer A may be a pressure-sensitive adhesive layer a3 containing a heating element. This is because both sides of the adhesive layer A can have tackiness at room temperature, allowing it to be stuck to and adhered to an adherend or other layers constituting the pressure-sensitive adhesive tape of the present invention.

[0109] Furthermore, in the adhesive layer A of the third embodiment, the adhesive forming the adhesive layer a3 may be a hot melt adhesive. That is, the adhesive layer A may be a hot melt adhesive layer a3 containing a heating element. Because a hot melt adhesive exhibits adhesive properties when heated, the adhesive layer A, which is a hot melt adhesive layer, can be easily attached and bonded to other layers constituting the pressure-sensitive adhesive tape or to an adherend by heating.

[0110] In the adhesive layer A of the third embodiment, the details of the adhesive forming the adhesive layer a3 can be the same as those described above in the section "<<Adhesive>>." The details of the heating element b included in the adhesive layer a3 can be the same as those described above in the section "<<Heater>>."

[0111] When the adhesive layer A is a single layer, the total thickness of the adhesive layer A is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 15 μm to 500 μm, more preferably 30 μm to 400 μm, and even more preferably 50 μm to 300 μm.

[0112] [Other aspects] Other embodiments of the adhesive layer A, which is a laminate, include, but are not limited to, the following lamination structures: In the lamination structure, " / " represents the lamination interface, and for example, "Layer A / Layer B" indicates that Layer A and Layer B are in direct contact with each other. A laminated structure in the order of melt-softening layer c / adhesive layer a1 / heat generating element b / adhesive layer a2 ·Laminated structure in the order of adhesive layer a1 / heating element b / adhesive layer a2 / melt-softening layer c A laminated structure in the order of melt-softening layer c1 / adhesive layer a1 / heating element b / adhesive layer a2 / melt-softening layer c2 A laminated structure in which the adhesive layer a1 containing the heating element b is laminated in the order of the adhesive layer a2 not containing the heating element b A laminated structure in which adhesive layer a1 containing heating element b is laminated in this order, followed by adhesive layer a2 containing heating element b.

[0113] <Release layer> In addition to the adhesive layer A, the pressure-sensitive adhesive tape may have other layers such as a release layer D. The release layer is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include glassine paper, kraft paper, clay-coated paper, paper laminated with a film such as polyethylene, paper coated with a resin such as polyvinyl alcohol or an acrylic acid ester copolymer, and a synthetic resin film such as polyester or polypropylene coated with a release agent such as a fluororesin or silicone resin, etc. The release layer may be provided on one side or both sides of the pressure-sensitive adhesive tape.

[0114] <Other layers> The tape of the present invention is not limited in its configuration as long as it contains at least an adhesive layer A and the outermost layers (excluding the release layer D) positioned opposite each other in the thickness direction have adhesive surfaces that can be bonded to an adherend. In addition to the above-mentioned adhesive layer A and the optional release layer D, the tape may also contain other layers such as a functional layer E having insulating, heat-insulating or heat-shielding functions, such as an insulating layer or a heat-insulating layer (e.g., a foamed resin layer, a hollow-containing layer, a hollow particle-containing layer, etc.), and an adhesive layer (pressure-sensitive adhesive layer) F that constitutes the adhesive surface of the adhesive tape.

[0115] [Adhesive tape composition] The pressure-sensitive adhesive tape of the present invention may have any configuration as long as it has at least an adhesive layer A, and may have, for example, the configurations exemplified below, but is not limited to these. In the following laminate configurations, " / " represents the lamination interface, and for example, in "Layer A / Layer B", Layer A and Layer B are in direct contact with each other. Peel layer D / adhesive layer A configuration Peel layer D / adhesive layer A / peel layer D configuration ·Composition of peeling layer D / adhesive layer F / functional layer E / adhesive layer A · Composition of adhesive layer F / functional layer E / adhesive layer A / peeling layer D ·Composition of release layer D / adhesive layer F / functional layer E / adhesive layer A / release layer D · Structure of adhesive layer F / functional layer E / adhesive layer A / functional layer E / adhesive layer F / release layer D ·Composition of release layer D / adhesive layer F / functional layer E / adhesive layer A / functional layer E / adhesive layer F / release layer D

[0116] In the pressure-sensitive adhesive tape of the present invention, both sides of the adhesive layer A may be the adhesive surface for contacting the adherend, or the pressure-sensitive adhesive layer F provided on one or both sides of the adhesive layer A may be the adhesive surface for contacting the adherend.

[0117] When the adhesive layer A is a laminate and the pressure-sensitive adhesive tape has a release layer D in contact with one or both sides of the adhesive layer A, the outermost layer of the adhesive layer A in contact with the release layer D may be a pressure-sensitive adhesive layer or a hot-melt adhesive layer, but is preferably a pressure-sensitive adhesive layer because it allows bonding to the adherend at room temperature. Also, when the adhesive layer A is a single layer and the pressure-sensitive adhesive tape has a release layer D in contact with one or both sides of the adhesive layer A, the adhesive layer A is preferably a pressure-sensitive adhesive layer.

[0118] When the adhesive layer A is a laminate and the pressure-sensitive adhesive tape has a release layer D on one or both sides of the adhesive layer A via another layer, the outermost layer of the adhesive layer A may be a pressure-sensitive adhesive layer or a hot-melt adhesive layer, as long as it is capable of room temperature or heat adhesion to the other layer. In particular, it is preferable that the outermost layer of the adhesive layer A is a pressure-sensitive adhesive layer. The same applies when the adhesive layer A is a single layer and the pressure-sensitive adhesive tape has a release layer D on one or both sides of the adhesive layer A via another layer.

[0119] The pressure-sensitive adhesive layer F can be formed using a known pressure-sensitive adhesive, and for example, the pressure-sensitive adhesive described for the adhesive layer A can be used.

[0120] [Adhesive tape applications] The pressure-sensitive adhesive tape of the present invention has both surfaces, excluding the release liner, that function as adhesive surfaces (adhesive surfaces), and therefore adherends can be attached to both surfaces of the pressure-sensitive adhesive tape, making it suitable for use in joining adherends together.The pressure-sensitive adhesive tape of the present invention can be peeled off by resistance heating, and is therefore used as a resistance heating (electrical heating) peeling tape.

[0121] The pressure-sensitive adhesive tape of the present invention is not particularly limited, and can be suitably used for bonding rigid adherends and separating adherends from each other. The pressure-sensitive adhesive tape of the present invention can be easily disassembled by resistance heating when separating components during reuse or recycling. Therefore, it can be used in applications where peeling of the pressure-sensitive adhesive tape is required. For example, it can be suitably used as a pressure-sensitive adhesive tape for fixing components of various products in industrial applications such as electronic devices, automobiles, building materials, office automation, and home appliances. The work efficiency is also good when separating a large number of components during reuse or recycling, or when peeling a large number of labels.

[0122] [Adhesive tape manufacturing method] When the pressure-sensitive adhesive tape has a planar heating element or an integrally molded mesh-like heating element, the method for producing the pressure-sensitive adhesive tape may include, for example, a method in which a composition containing the adhesive is coated on a release sheet, and after a drying process, the sheet is laminated to each side of the heating element in order.When the pressure-sensitive adhesive tape has a particulate or fibrous heating element, the method may include, for example, a method in which a composition containing a particulate or fibrous heating element and an adhesive is coated on a release sheet, and after a drying process, another release sheet is laminated.

[0123] 2.Goods The article of the present invention comprises at least two adherends and at least the pressure-sensitive adhesive tape of the present invention between the two adherends, with the two adherends bonded together via the pressure-sensitive adhesive tape. Examples of a method for bonding the adherends include a method in which an adherend is attached to each adhesive surface of the pressure-sensitive adhesive tape, and the two adherends are bonded together. The article is not particularly limited and can be selected appropriately depending on the purpose, but is preferably an electronic device, a component built into an electronic device, or the like. In the article, it is preferable that, in a plan view, the pressure-sensitive adhesive tape has a pair of extensions extending from the outer periphery of the adherend.

[0124] <Adhesive tape> Details of the adhesive tape in the article of the present invention are as already described in the section "1. Adhesive tape."

[0125] <Adherend> The adherend may be rigid or flexible like a film. The adherend is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a metal plate, a metal housing, a metal cover, a glass plate, a plastic plate, etc.; a part having any of these on the adhesion surface, etc. The two adherends bonded via the pressure-sensitive adhesive tape may be the same or different.

[0126] As shown, for example, in the schematic plan view of FIG. 4A and the schematic cross-sectional view of FIG. 4B, an article 100 of the present invention is an article in which two adherends 50 are bonded via the adhesive tape 10, the article including two adherends 50 and an adhesive tape 10 including an adhesive layer A, which is a laminate in which adhesive layer a1 / planar heating element b / adhesive layer a2 are laminated between the two adherends 50. In a plan view (FIG. 4A), both ends in the longitudinal direction of the adhesive tape 10 extend from the periphery of the adherends. Furthermore, both ends in the longitudinal direction of the planar heating element b extend from the periphery of the adhesive layer a1 and the adhesive layer a2. The extending ends of the adhesive tape 10 can be used as a pair of terminals for electrically connecting to a power source in the article disassembly method described below, making it possible to easily pass electricity through the heating element b of the adhesive tape 10.

[0127] Furthermore, as shown in the schematic cross-sectional view of Figure 5, the article 300 of the present invention may be an article comprising two adherends 50 and an adhesive tape 30 consisting of a heating element b and an adhesive layer a3 containing an adhesive between the two adherends 50, and in which the two adherends 50 are bonded via the adhesive tape 30.

[0128] In a plan view of the article, the adhesive tape may be attached to the entire adherend surface, which is the surface of the adherend facing the adhesive tape, or the adhesive tape may be attached to a portion of the adherend surface. In particular, as illustrated in Fig. 4A, it is preferable that adhesive tape 10 is attached to a portion of the adherend surface of adherend 50. The small contact area between the adherend and the adhesive tape is advantageous in that when the adhesive tape is peeled from the adherend by resistance heating, a peeling initiation point is more likely to occur between the adherend and the adhesive tape, facilitating peeling.

[0129] As illustrated in FIG. 4A, when the adhesive tape 10 is attached to a portion of the adherend surface of the adherend 50 in a plan view of the article of the present invention, the planar shape of the adhesive tape 10 in the article may be strip-shaped or linear, or may be a patterned shape.

[0130] Furthermore, when the article of the present invention is viewed in a plane, and the adhesive tape is attached to the entire adherend surface, which is the surface of the adherend facing the adhesive tape, the planar shape of the planar heating element in the adhesive tape may be the same as the planar shape of the adhesive tape, or may be strip-shaped, linear, or patterned.

[0131] 3. How to dismantle items The method for dismantling an article of the present invention is a method for dismantling an article of the present invention, or a method for dismantling an article in which two adherends are bonded via the adhesive tape of the present invention, and includes a separation step and, if necessary, further includes other steps.

[0132] Details regarding the articles and the adhesive tape used for the articles in the dismantling method of the present invention are the same as those explained in the above sections "2. Articles" and "1. Adhesive Tape."

[0133] <Separation process> The separation process is a process in which the adhesive layer A is electrically connected to a power source, electricity is passed from the power source to the heating element, and the adhesive layer A is softened or melted by resistance heating, thereby separating the two adherends.

[0134] The power source is not particularly limited and can be selected appropriately depending on the purpose. It may be an external power source or a power source for driving the article, which is an electronic device or a component built into an electronic device, but is preferably a power source for driving the electronic device or a component built into an electronic device. Furthermore, when the article is an electronic device or a component built into an electronic device, and the power source is the driving power source of the electronic device, it is preferable that the separation process is a process of electrically connecting the adhesive layer A to the driving power source and electrical circuit of the electronic device, passing electricity from the driving power source to the heating element, and melting or softening the adhesive layer A by resistance heating to separate the two adherends.

[0135] The electrical connection can be achieved by electrically connecting the adhesive layer A (preferably the heating element or both ends of the extended heating element) to a power source using known means such as alligator clips. The electrical circuit and the electrical connecting means are preferably formed from a conductive material exhibiting a volume resistivity different from that of the heating element material in the pressure-sensitive adhesive tape, and more preferably from a conductive material having a volume resistivity lower than that of the heating element. By forming the means from a conductive material having a volume resistivity lower than that of the heating element, it is possible to electrically connect the heating element and the electrical circuit and pass current from the driving power source to the heating element, which is advantageous in that it prevents the electrical circuit and the electrical connecting means from being excessively heated, and allows voltage to be efficiently applied to the adhesive layer A, enabling peeling in a short time.

[0136] The method of applying electricity can be appropriately selected depending on the size of the pressure-sensitive adhesive tape, the type of heating element used, etc., and examples include a method of applying a voltage of 0.1 V to 200 V until the adhesive layer A melts or softens (for example, for 0.5 seconds to 30 minutes). For example, as schematically shown in Figure 6, a simple power supply can be used. By electrically connecting the adhesive layer A to the power supply and applying a voltage to the heating element to pass electricity, the heating element and its surroundings are heated by resistance heating. As a result, the adhesive or any melt-softened layer in the adhesive layer A softens or melts, and the adhesive layer A itself or a desired position within the adhesive layer A is released from its adhesive state, making the adhesive layer A peelable and the bonded adherends dismantled.

[0137] The voltage applied to the heating element by energization is not particularly limited, but is preferably 0.1 V or more and 200 V or less, more preferably 0.5 V or more and 150 V or less, and even more preferably 1.0 V or more and 100 V or less. In the pressure-sensitive adhesive tape of the present invention, the adhesive layer A softens or melts in a short time even when a low voltage is applied. Therefore, by applying a voltage within the above range in the separation step, articles can be disassembled in a short time without applying excessive voltage, and damage to the articles can be prevented. In particular, by applying a voltage that can be handled by small electronic devices and household electrical appliances, these articles can be easily disassembled.

[0138] The current applied to the heating element is not particularly limited, but is preferably 0.01 A to 20 A, more preferably 0.03 A to 15 A, more preferably 0.05 A to 10 A, and even more preferably 0.1 A to 5 A. In the pressure-sensitive adhesive tape of the present invention, the adhesive layer A softens or melts in a short time. Therefore, by applying a current within the above range in the separation step, the article can be disassembled in a short time by applying the same current as that used in general-purpose electronic devices and home appliances, and damage to the article can be prevented. In particular, by applying a current compatible with small electronic devices and home appliances, these articles can be easily disassembled.

[0139] The current application time is not particularly limited, but is preferably from 0.5 seconds to 30 minutes, more preferably from 0.5 seconds to 120 seconds, and even more preferably from 0.5 seconds to 30 seconds. By applying an appropriate voltage within this range, the articles can be dismantled in a short time without damaging them. [Example]

[0140] The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples. Unless otherwise specified, "parts" refers to "parts by mass" and "%" refers to "% by mass".

[0141] Furthermore, the configurations of the pressure-sensitive adhesive tapes shown in the Examples and Reference Examples exclude the release liner, and the total thickness of the pressure-sensitive adhesive tape does not include the thickness of the release liner.

[0142] <Methods for measuring physical properties> (Storage modulus G 23 , and storage modulus G 100 ) Storage modulus G of adhesive layer a formed with adhesive compositions (P-1) and (P-2) 23 , and storage modulus G 100was measured by the following method. Using a viscoelasticity tester (ARES-G2, manufactured by TA Instruments Japan), a test specimen was sandwiched between parallel disks with a diameter of 8 mm, which are the measuring section of the tester, and the storage modulus G' was measured under conditions of a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a heating rate of 2°C / min, and the values ​​were recorded at 23°C and 100°C. The test specimens used were adhesive layers (pressure-sensitive adhesive layers) that had been coated with the adhesive composition using an applicator to a dry thickness of approximately 2 mm, dried, and then aged in an environment of 40°C for 48 hours.

[0143] (Measured volume resistivity of heating element) The actual measured values ​​of the volume resistivity of the heating elements used in the examples and reference examples were values ​​measured at room temperature of 20°C using a low resistivity meter (manufactured by Nitto Seiko Analytech Co., Ltd., product name: "Loresta-AX MCT-T370") and a four-point probe (manufactured by Nitto Seiko Analytech Co., Ltd., product name: "ASP Probe MCP-TP03P") in accordance with JIS K 7194. Measurement was performed at one point, and a resistivity correction coefficient of 4.532 was used.

[0144] <Preparation of Adhesive Composition (P-1)> 100 parts by mass of styrene-isoprene block copolymer composition a (a mixture of styrene-isoprene diblock copolymer and styrene-isoprene triblock copolymer, 24% by mass of styrene-derived structural units represented by the following chemical formula (1), the ratio of styrene-isoprene diblock copolymer to the total amount of composition a being 67% by mass), 40 parts by mass of Quinton G115 (a C5 / C9 petroleum resin manufactured by Zeon Corporation, softening point 115°C), and Pencel D-160 An adhesive composition (P-1) was obtained by mixing 30 parts by mass of (polymerized rosin ester resin manufactured by Arakawa Chemical Industries, Ltd., softening point 15°C to 150°C), 5 parts by mass of Nippon Oil Polybutene HV-50 (polybutene manufactured by JX Nippon Oil & Energy Corporation, pour point -12.5°C), and 1 part by mass of antioxidant (tetrakis-[methylene-3-(3'5'-di-t-butyl-4-hydroxyphenyl)propionate]methane) and dissolving the mixture in 100 parts by mass of toluene as a solvent.

[0145] [ka]

[0146] <Preparation of Adhesive Composition (P-2)> A reaction vessel equipped with a stirrer, reflux condenser, nitrogen inlet tube, and thermometer was charged with 79.9 parts by weight of n-butyl acrylate, 6 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of cyclohexyl acrylate, 4 parts by weight of acrylic acid, 0.1 parts by weight of 4-hydroxybutyl acrylate, and 200 parts by weight of ethyl acetate. Nitrogen bubbling was performed at room temperature for 1 hour under stirring to obtain a mixture. Next, 2 parts by weight of 2,2'-azobis(2-methylbutyronitrile) solution (solids content: 1.0% by weight) previously dissolved in ethyl acetate was added to the mixture, and the mixture was stirred at 72°C for 4 hours, followed by 5 hours at 75°C. The resulting mixture was then diluted with ethyl acetate and filtered through a 200-mesh wire screen to obtain an acrylic copolymer (A-1) solution (solids concentration: 26%) with a weight-average molecular weight of 1,060,000 and an average number of carbon atoms in the saturated hydrocarbon groups of the alkyl acrylate monomers of 4.4. An adhesive composition (P-2) was obtained by blending 1.0 part by mass of an adduct of tolylene diisocyanate and trimethylolpropane as a crosslinking agent ("Burnoc D-40" manufactured by DIC Corporation, isocyanate-based crosslinking agent, solid content 40%, hereinafter referred to as "D-40") into 100 parts by mass of the acrylic copolymer (A-1) solution.

[0147] Example 1 <Preparation of adhesive tape> The adhesive composition (P-1) was applied to the release-treated surface of a release liner (a 75 μm-thick polyethylene terephthalate film with one release-treated side) to a dry thickness of 50 μm, and then dried at 90° C. for 3 minutes to produce adhesive layer a1. Next, the adhesive composition (P-2) was applied to the release-treated surface of a release liner (a 75 μm-thick polyethylene terephthalate film with one release-treated side) to a dry thickness of 50 μm, and then dried at 90° C. for 3 minutes to produce adhesive layer a2. A 10 μm-thick nichrome foil (Takeuchi Metal Foil Powder Co., Ltd., "Nichrome NCH1-H") was used as the heating element.

[0148] A 50 mm long, cut-to-width adhesive layer a1 was bonded to a 100 mm long nichrome foil using a hand roller, and the nichrome foil was positioned so that both ends of the nichrome foil extended 25 mm in the longitudinal direction. Similarly, a 50 mm long, cut-to-width adhesive layer a2 was bonded to the opposite side of the nichrome foil bonded to the adhesive layer a1, and the laminate was laminated from the top surface of the release liner using a roll with a linear pressure of 5 kg / cm to create a laminate with a total thickness of 110 μm, in which both ends of the nichrome foil extended 25 mm in the longitudinal direction from the outer periphery of the adhesive layer a1 and adhesive layer a2, and then aged in an environment of 40°C for 48 hours. This was cut to a width of 2 mm, and adhesive layers a1 and a2 were 2 mm wide x 50 mm long, and the nichrome foil was 2 mm long x 100 mm long, with the nichrome foil having a pair of extensions extending from the outer periphery of adhesive layer a1 and adhesive layer a2, to obtain pressure-sensitive adhesive tape (T-1) of Example 1. The catalog value for the volume resistivity of the nichrome foil was 108 μΩ cm, and the measured value was 105 μΩ cm.

[0149] The viscoelastic parameters of the adhesive layer a formed from the adhesive composition (P-1) were the storage modulus G at 23°C 23 : 3.E+05, Loss tangent (tanδ) at 23°C: 0.33, Storage modulus G at 100°C 100 : 8.E+04, loss tangent (tan δ) at 100°C: 0.48, temperature at which the loss tangent (tan δ) of the adhesive layer a1 becomes 0.45 or more: 94°C or more.

[0150] The viscoelastic parameters of the adhesive layer a formed from the adhesive composition (P-2) were the storage modulus G at 23°C 23 : 9.E+04, Loss tangent (tanδ) at 23°C: 0.69, Storage modulus G at 100°C 100 : 2.E+04, loss tangent (tan δ) at 100°C: 0.33, temperature at which the loss tangent (tan δ) of the adhesive layer a2 becomes 0.45 or more: over 150°C.

[0151] <Production of items> The release liner on the adhesive layer a1 side of the pressure-sensitive adhesive tape of Example 1 (indicated by the symbol 10 in FIGS. 8A-C) was peeled off, and the tape was applied to an adherend 50a (glass, width 40 mm × length 50 mm × thickness 10 mm) so that the 50 mm length of the tape adhesive surface (effective portion) crossed the center of the adherend 50a along the width direction of the adherend 50a (see FIGS. 8A-C). Next, the release liner on the adhesive layer a2 side was peeled off, and the tape was applied to an adherend 50b (glass, width 30 mm × length 100 mm × thickness 2.8 mm) in a sandwiched shape (see FIGS. 8A-C), and a pressure of 20 N / cm was applied. 2 The resulting adhesive was left to stand in an atmosphere of 23° C. and 50% RH for 24 hours or more to obtain the article of Example 1.

[0152] Example 2 An adhesive tape (T-2) and article of Example 2 having a total thickness of 110 μm were obtained in the same manner as in Example 1, except that a 10 μm thick stainless steel foil (manufactured by Takeuchi Metal Foil Powder Co., Ltd., product name: "Stainless Steel SUS304-H") having a catalog value of 72.0 μΩ·cm and an actual measured value of 79.9 μΩ·cm was used instead of the nichrome foil.

[0153] Example 3 An adhesive tape (T-3) and article of Example 2 having a total thickness of 110 μm were obtained in the same manner as in Example 1, except that a 10 μm thick stainless steel foil (manufactured by Takeuchi Metal Foil Powder Co., Ltd., product name: "Stainless Steel SUS430-H") having a catalog value of 60.0 μΩ·cm and an actual measured value of 62.0 μΩ·cm was used instead of the nichrome foil.

[0154] Example 4 An adhesive tape (T-4) and article of Example 2 having a total thickness of 110 μm were obtained in the same manner as in Example 1, except that a 10 μm-thick titanium foil (manufactured by Takeuchi Metal Foil Powder Co., Ltd., product name: "Titanium Type 1 TR270C-H") having a catalog value of 55.0 μΩ·cm and an actual measured value of 51.8 μΩ·cm was used instead of the nichrome foil.

[0155] Example 5 An adhesive tape (T-5) and an article of Example 2 having a total thickness of 110 μm were obtained in the same manner as in Example 1, except that a 10 μm-thick nickel silver foil (manufactured by Takeuchi Metal Foil and Powder Co., Ltd., product name: "Nickel Silver C7701") having a catalog value of 34.0 μΩ·cm and an actual measured value of 33.1 μΩ·cm was used instead of the nichrome foil.

[0156] Example 6 7.5 g of an amphoteric surfactant (manufactured by Toho Chemical Industry Co., Ltd., trade name: "Obazolin CAB-30") and 7.6 g of carbon nanotubes (manufactured by Nanocyl Corporation, trade name: "NC7000") were mixed in 500 ml of water to prepare an aqueous solution, which was then placed in a ball mill body (volume = 900 ml, ball mill diameter = 130 mm, ball loading amount = 1600 g) and stirred to form a paste. The ball mill body was then placed on a rotating stand and stirred for 2 hours. The entire amount of the obtained dispersion liquid was removed from the ball mill body, and 250 ml of a 15% aqueous solution of the amphoteric surfactant was added. The mixture was then loaded into a bead mill (manufactured by WAB, trade name: "Dynomill ECM-AP2", internal volume = 1900 ml, filled with 1800 g of zirconia beads with a diameter of 0.6 mm), and stirred for 60 minutes at a rotation speed of 300 rpm to prepare an aqueous dispersion of carbon nanotubes containing amphoteric surfactant (carbon nanotube concentration = 0.99 wt%).

[0157] The aqueous dispersion of carbon nanotubes was applied to one side of a 25 μm-thick polyimide film (manufactured by DuPont-Toray Co., Ltd., product name: Kapton 100H) using a bar coater so that the film would have a thickness of 3 μm after drying. The coating was dried at 100°C for 10 minutes to form a carbon nanotube layer on one side of the polyimide film, yielding a carbon nanotube-coated film. The actual volume resistivity of the carbon nanotube layer was measured to be 19,270 μΩ·cm.

[0158] An adhesive tape (T-6) and article of Example 6 having a total thickness of 128 μm were obtained in the same manner as in Example 1, except that the carbon nanotube coated film was used instead of the nichrome foil of Example 1. The carbon nanotube coated film was attached with the carbon nanotube layer adjacent to the adhesive layer a1.

[0159] Example 7 Instead of nichrome foil, metal nonwoven fabric (material: SUS316L, thickness 25 μm, density 1.6 g / cm 3 An adhesive tape (T-7) and article of Example 7 having a total thickness of 125 μm were obtained in the same manner as in Example 1, except that a 1000-kJ / cm adhesive tape (T-7) having a fiber diameter of 7 μm and a measured volume resistivity of 783 μΩ·cm was used.

[0160] Example 8 A crystalline polyester resin coating material (manufactured by Mitsubishi Chemical Corporation, trade name: "Nichigo Polyester MSP-640", melting point 100 ° C, molecular weight 10,000, tack-free) (P-3) was applied to the release-treated surface of a release liner (a 75 μm-thick polyethylene terephthalate film with one side treated for release) so that the thickness after drying was 50 μm, and the coating was dried at 90 ° C for 3 minutes to produce a melt-softened layer c. The melt-softened layer c, cut to an arbitrary width with a length of 50 mm, was attached to one side of a 100 mm long nichrome foil with a hand roller, and the nichrome foil was positioned so that it extended 25 mm at both ends in the longitudinal direction. The laminate was then laminated with a roll at 120 ° C and a linear pressure of 5 kg / cm to form a multilayer body. Next, two 50 μm thick adhesive layers were prepared by applying the adhesive composition (P-2) onto a release liner and drying it in the same manner as in Example 1. The adhesive layers were then cut to lengths of 50 mm and arbitrary widths, and the release liner of the multilayer body was peeled off, followed by laminating the adhesive layers to both sides of the multilayer body and laminating them with a roll at a linear pressure of 5 kg / cm to form adhesive layer a1 and adhesive layer a2. In this way, a pressure-sensitive adhesive tape (T-8) and article of Example 8 having a total thickness of 160 μm were obtained.

[0161] (Reference example 1) An adhesive tape (T-9) and an article of Reference Example 1 having a total thickness of 110 μm were obtained in the same manner as in Example 1, except that a 10 μm-thick nickel foil (manufactured by Takeuchi Metal Foil Powder Co., Ltd., product name: "Nickel Ni-H") having a catalog value of 8.5 μΩ·cm and an actual measured value of 8.2 μΩ·cm was used instead of the nichrome foil.

[0162] (Reference example 2) An adhesive tape (T-10) and an article of Reference Example 2 having a total thickness of 110 μm were obtained in the same manner as in Example 1, except that a 10 μm-thick copper foil (manufactured by Takeuchi Metal Foil Powder Co., Ltd., product name: "Copper C1020R-H") having a catalog value of 1.7 μΩ·cm and an actual measured value of 1.9 μΩ·cm was used instead of the nichrome foil.

[0163] (Reference example 3) An adhesive tape (T-11) and an article of Reference Example 3 having a total thickness of 112 μm were obtained in the same manner as in Example 1, except that a 12 μm thick PET film (manufactured by Unitika Ltd., product name: "PETB") was used instead of the nichrome foil. The PET film was not electrically conductive and had a volume resistivity of >10 23 The value was μΩ·cm (literature value).

[0164] <Evaluation> <<Peel strength>> [Push strength before heating] Using the articles of Examples 1 to 7 and Reference Examples 1 to 3 as test pieces, the adhesive tape peel strength (G1) was measured by pressing a glass plate at the pressing position shown in Figure 8A in the direction of the arrow using probe 70 shown in Figures 8B and 8C at a speed of 10 mm / min in an environment of 23°C. [Push strength after 10 seconds of heating] Next, the extension e of the metal foil (heating element) in the pressure-sensitive adhesive tape 10 of the test piece was clamped with an alligator clip 60, and a current of 3.7 A was passed using a dry cell battery and a resistor (manufactured by uxcell, product name: "Metal Clad Resistor"), and 10 seconds after the start of the current passage, the glass plate was pressed at a speed of 10 mm / min, and the adhesive strength (G2) at this time was measured. In addition, in the evaluation of the article obtained in Example 6 (pressure-sensitive adhesive tape (T-6)), a current of 0.06 A was passed using a DC stabilized power supply (manufactured by Kikusui Electronics Co., Ltd., product name: "PAS160-1") instead of a dry cell battery, and the adhesive strength (G2) was measured in the same manner.

[0165] [Push strength reduction rate] The push strength reduction rate was calculated using the push strength (G1) measured before heating and the push strength (G2) measured 10 seconds after heating according to the following formula. Push strength reduction rate (%) = 1-(G2 / G1) x 100 The results are shown in Table 1. In Examples 1 to 6 and Reference Examples 1 to 3, peeling occurred within the adhesive layer a1. In Example 7, peeling occurred at the interface between the metal nonwoven fabric and the adhesive layer a1. In Example 8, fracture occurred within the melt-softened layer c.

[0166] <<Temperature of the adherend>> In measuring the peel time, the temperature of the adherend was measured over time, and the maximum temperature reached by the adherend during disassembly was measured. The temperature of the adherend was measured using a thin temperature sensor (device name: ST-50 (K thermocouple), manufactured by Rika Kogyo Co., Ltd.) and a recorder (device name: midi LOGGER GL200A, manufactured by Graphtec Corporation), with the thermocouple set on the surface (opposite side from the adhesive tape) of adherend 50b (glass, 30 mm wide x 100 mm long x 2.8 mm thick). The results are shown in Table 1.

[0167] <<Ease of heating operation>> The ease of heating operation was evaluated based on the following criteria, and the results are shown in Table 1. [Evaluation criteria] ⊚: The power supply or external device is simple, and electrical connection to the power supply is also very easy. ◯: The power supply or external device is simple, and electrical connection to the power supply is also easy. △: The power supply or external device is simple, but electrical connection to the power supply is not easy. ×: The power supply or external device is not simple, and electrical connection to the power supply is not easy. -: Could not be peeled off.

[0168] [Table 1]

[0169] The results of Example 1 show that the adhesive strength after 10 seconds of resistance heating was significantly reduced compared to before heating, reaching 71%. In contrast, in Reference Examples 1 and 2, which used heating elements with volume resistivities of less than 30 μΩ·cm, the strength reduction rates were only 3% and 1%, respectively. Therefore, it was found that Example 1 enabled peeling in a shorter time than Reference Examples 1 and 2. The results of Examples 1 to 8 showed that the strength reduction rate varied depending on the volume resistivity of the heating element, and that peeling in a shorter time within a practical range was possible when the volume resistivity was 30 μΩ·cm or higher. Furthermore, thermal peeling was easily achieved by connecting to a power source (dry cell battery) without using large-scale equipment such as electromagnetic induction heating or other heating methods. In Reference Example 3, shown for reference, the PET film was not electrically connected, so resistance heating did not occur and peeling was not possible. [Industrial Applicability]

[0170] The present invention can be used as an adhesive tape used to fix components in various electronic devices, such as portable electronic (electrical) devices such as mobile phones, smartphones, tablet PCs, portable music players, and PDAs, wearable devices such as smart watches and VR goggles, digital cameras, videos, car navigation systems, personal computers, displays, monitors, televisions, game consoles, air conditioners, and copy machines.

[0171] This application claims priority from Japanese Patent Application No. 2021-114334, filed on July 9, 2021, and incorporates by reference all of the contents of that Japanese application. [Explanation of symbols]

[0172] a1, a2, a3 adhesive layer b Heating element c Melt-softened layer e. Extension part (of heating element) 10, 20, 30 adhesive tape 50 Adherent 100, 300 items 60 alligator clips 70 probes P Press position

Claims

1. an adhesive layer A containing a heating element and an adhesive; The volume resistivity of the heating element is 30 μΩ cm or more, The shape of the heating elements is a shape in which the heating elements are in electrical contact with each other to generate resistance heating, and is in a planar, mesh, particle, or fiber shape; a temperature at which the loss tangent (tanδ) of the adhesive layer A formed by the adhesive is 0.45 or more is in a temperature range of 80°C or more and 200°C or less; The adhesive tape is characterized in that the adhesive layer A melts or softens due to resistance heating of the heating element, causing peeling within the adhesive layer A and making it peelable.

2. 2. The pressure-sensitive adhesive tape according to claim 1, wherein the adhesive is at least one of a pressure-sensitive adhesive and a hot-melt adhesive.

3. 2. The pressure-sensitive adhesive tape according to claim 1, wherein the heating element is selected from the group consisting of nichrome, stainless steel, titanium, nickel silver, and carbon.

4. The adhesive layer A is a laminate having the planar heating element and an adhesive layer a1 and an adhesive layer a2 on each surface of the heating element, The pressure-sensitive adhesive tape according to claim 1 , wherein at least one of the adhesive layer a1 and the adhesive layer a2 is melted or softened by resistance heating to become peelable.

5. The pressure-sensitive adhesive tape according to claim 4 , wherein the planar heating element has a pair of extending portions extending from outer peripheries of the adhesive layer a1 and the adhesive layer a2 in a plan view.

6. The pressure-sensitive adhesive tape according to claim 1 , wherein the adhesive layer A is a single layer containing the heating element and the adhesive.

7. At least two adherends; An article comprising the adhesive tape according to any one of claims 1 to 6 between two adherends, wherein the two adherends are bonded via the adhesive tape.

8. The article according to claim 7 , wherein the pressure-sensitive adhesive tape has, in a plan view, a pair of extension portions extending from the outer periphery of the adherend.

9. The method for dismantling an article according to claim 7, A method for dismantling an article, comprising electrically connecting the adhesive layer A to a power source, passing electricity from the power source to the heating element, and softening or melting the adhesive layer A by resistance heating to separate the two adherends.

10. The method for dismantling articles according to claim 9, wherein the power source is an external power source.

11. The article is an electronic device or a component built into an electronic device, the power supply is a driving power supply for the electronic device, 10. The method for dismantling articles according to claim 9, wherein the adhesive layer A is electrically connected to the driving power source and the electric circuit of the electronic device, and electricity is passed from the driving power source to the heating element, melting or softening the adhesive layer A by resistance heating to separate the two adherends.

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