Adhesive tape, article, and method for disassembling an article

Abstract

The present application provides an adhesive tape capable of heating and peeling in a short time and capable of preventing thermal damage to an adherend. The present application is an adhesive tape comprising: an intermediate layer A containing a heat generator and an adhesive; an adhesive layer B1 containing an adhesive and disposed on one side of the intermediate layer A; and an adhesive layer B2 containing an adhesive and disposed on the other side of the intermediate layer A, at least either of the adhesive layer B1 and the adhesive layer B2 being a thermal insulation layer C having thermal insulation, or the adhesive tape further comprising a thermal insulation layer C having thermal insulation at at least either of a position between the intermediate layer A and the adhesive layer B1 and a position between the intermediate layer A and the adhesive layer B2, the adhesive tape being capable of peeling by heating.

Description

Technical Field

[0001] The present invention relates to an adhesive tape (the Japanese term for "adhesive" is "adhesion"), an article, and a method for disassembling the article. Background Art

[0002] As a joining method excellent in workability and high in bonding reliability, adhesive tapes are used for component fixing applications, temporary component fixing applications, label applications for displaying product information, etc. in various industrial fields such as OA equipment, IT products, home appliances, and automobiles. In recent years, from the viewpoint of global environmental protection, requirements for recycling and reuse of used products have increased in various industrial fields such as home appliances and automobiles. When recycling and reusing various products, an operation of peeling off the adhesive tape used for fixing components and labels is required. However, since adhesive tapes are arranged at various positions in products, it is expected to reduce the operation cost through a simple removal process.

[0003] In order to separate adherends from each other, for example, a hot-melt adhesive composition that can be rapidly melted in a short time by electromagnetic induction heating has been proposed (for example, refer to Patent Document 1). As a method for separating adherends from each other, a method for demolishing a building is proposed, in which a metal base material is heated by an electromagnetic induction heating device, so that the adhesive between the base material and the interior trim material is heated, foamed and peeled off, and the interior trim material is peeled off from the metal base material (for example, refer to Patent Document 2). In addition, a double-sided adhesive tape having a thermally conductive layer that can be easily disassembled by directly heating the thermally conductive layer through contact with a heat generation source is proposed (for example, refer to 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 Technical Problem to be Solved by the Invention

[0005] However, in conventional methods of peeling and disassembling by heating, since heat is applied from the outside, when heat required for peeling the adhesive tape is generated from a heating element, there is a problem that thermal degradation and thermal damage may occur to the adherend due to the generated heat. On the other hand, when thermal degradation and thermal damage to the adherend are intended to be suppressed, the heat generation amount is reduced, so that the adhesive tape cannot be sufficiently heated, which causes a problem that peeling is difficult to achieve.

[0006] Therefore, in adhesive tapes that fix rigid bodies or other adhered objects to each other, it is desirable to have adhesive tapes that can disassemble and reuse the parts that are adhered objects, and even more desirable to have adhesive tapes that can be easily disassembled and peeled off by heating.

[0007] The technical problem of the present invention is to solve the various problems mentioned above and achieve the following objective: that is, the objective of the present invention is to provide an adhesive tape, an article, and a method for removing the article that can be peeled off by heating in a short time and can effectively prevent thermal damage to the adhered objects. Technical solutions for solving technical problems

[0008] This invention was made based on the above-described insights of the inventors, and the means for solving the aforementioned technical problems are as follows. That is, <1> An adhesive tape, characterized in that the adhesive tape comprises: an intermediate layer A including a heating element and an adhesive; an adhesive layer B1 disposed on one side of the intermediate layer A and including the adhesive; and an adhesive layer B2 disposed on the other side of the intermediate layer A and including the adhesive, wherein at least one of the adhesive layers B1 and B2 is an insulating layer C that also has heat insulation properties, or the adhesive tape further comprises an insulating layer C with heat insulation properties at at least any position between the intermediate layer A and the adhesive layer B1 and between the intermediate layer A and the adhesive layer B2, and the adhesive tape can be peeled off by heating. <2> According to the above <1> The adhesive tape described herein has an insulating layer C at two locations: between the intermediate layer A and the adhesive layer B1, and between the intermediate layer A and the adhesive layer B2. <3> According to the above <1> Up to the above <2> The adhesive tape according to any one of the following methods, wherein the aforementioned heat insulation layer is selected from the group consisting of a foam layer, a hollow layer, and a hollow particle layer. <4> According to the above <1> Up to the above <3> The adhesive tape according to any one of the following methods, wherein the thickness of the above-mentioned heat insulation layer C is 15 μm to 1000 μm. <5> According to the above <1> Up to the above <4> The adhesive tape according to any one of the following methods, wherein the volume resistivity of the heating element is 30 μΩ·cm or higher. <6> According to the above <5> The adhesive tape wherein the heating element is selected from the group consisting of nickel-chromium alloy, stainless steel, titanium, nickel silver, and carbon. <7> According to the above <1> Up to the above <6> The adhesive tape according to any one of the following, wherein the intermediate layer A has a planar heating element and adhesive layers a1 and a2 on each surface of the planar heating element. <8> According to the above <7> The adhesive tape, in a top view, has a pair of protrusions extending from the outer periphery of the adhesive layer a1 and the adhesive layer a2. <9> According to the above <7> Up to the above <8> The adhesive tape according to any one of the following methods, wherein at least one of the adhesive layer a1 and adhesive layer a2 is softened or melted by heating. <10> According to the above <1> Up to the above <6> The adhesive tape according to any one of the following methods, wherein the intermediate layer A is composed of a single layer comprising the heating element and the adhesive. <11> According to the above <1> Up to the above <10> The adhesive tape according to any one of the following methods, wherein the intermediate layer A is softened or melted by heating. <12> According to the above <1> Up to the above <11> The adhesive tape according to any one of the above-mentioned adhesives, wherein the temperature at which the loss tangent (tanδ) of the adhesive layer formed by the adhesive reaches 0.45 or more exists in a temperature region of 80°C or more and 200°C or less. <13> An article, characterized in that the article comprises at least two adhered objects and a space between the two adhered objects. <1> Up to the above <12> The adhesive tape described in any one of the above-mentioned adhesive tapes is used to bond the two objects together. <14> According to the above <13> The article described herein, wherein, in a top view, the adhesive tape has a pair of protrusions extending from the outer periphery of the object to be adhered to. <15> According to the above <13> Up to the above <14> The method for disassembling the article as described in any one of the above-mentioned methods involves softening or melting the intermediate layer A by heating the heating element, thereby separating the two adhered objects. <16> According to the above <15> The method for disassembling the items described herein involves heating the heating element by resistance heating, connecting the intermediate layer A to a power source, supplying power to the heating element from the power source, and softening or melting the adhesive layer A through resistance heating, thereby separating the two adhered items. Invention Effects

[0009] According to the present invention, the aforementioned problems can be solved and the above-mentioned objectives can be achieved, and an adhesive tape, article, and method for removing the article can be provided that can be peeled off by heating in a short time and can effectively prevent thermal damage to the adhered object. Attached Figure Description

[0010] Figure 1A This is a schematic cross-sectional view showing an example of the adhesive tape of the present invention. Figure 1B This is a schematic cross-sectional view showing another example of the adhesive tape of the present invention. Figure 1CThis is a schematic top view illustrating another example of the adhesive tape of the present invention. Figure 1D This is a schematic top view showing an example of a pattern of the heating element in the adhesive tape of the present invention. Figure 2 This is a schematic cross-sectional view showing another example of the adhesive tape of the present invention. Figure 3 This is a schematic cross-sectional view showing another example of the adhesive tape of the present invention. Figure 4 This is a schematic cross-sectional view showing another example of the adhesive tape of the present invention. Figure 5 This is a schematic cross-sectional view showing another example of the adhesive tape of the present invention. Figure 6A This is a schematic top view illustrating an example of the article of the present invention. Figure 6B This is a schematic cross-sectional view showing an example of the article of the present invention. Figure 7 This is a schematic diagram illustrating a method for disassembling the article of the present invention. Figure 8A This is a schematic top view of the adhesive tape of Example 1. Figure 8B This is a schematic cross-sectional view of the adhesive tape of Example 1. Figure 9A This is a schematic top view illustrating the article and evaluation method of Embodiment 1. Figure 9B This is a schematic front view illustrating the article and evaluation method of Embodiment 1. Figure 9C This is a schematic side view showing the article and evaluation method of Embodiment 1. Detailed Implementation

[0011] In this specification, "adhesion" is a type of bonding that refers to bonding through pressure, also known as "pressure-sensitive bonding". Correspondingly, "adhesive" refers to an adhesive that combines the properties of both liquids and solids, possesses tack, and exerts its bonding effect through pressure; also known as "pressure-sensitive adhesive".

[0012] 1. Adhesive tape The adhesive tape of the present invention has at least an intermediate layer A, an adhesive layer B1, an adhesive layer B2, and an insulating layer C, and may also have other layers such as a release layer as needed. The adhesive tape of the present invention is an adhesive tape that can be peeled off by heating.

[0013] The adhesive tape of the present invention can be used as an easily removable adhesive tape, which allows for easy removal of the adhesive between the adhered objects after a certain period of time following the application and fixation of the adhered objects. That is, it can be peeled off by heating the intermediate layer A, allowing the adhered objects to be removed. Compared to conventional methods of peeling and removing adhesive layers by heating, the adhesive tape of the present invention, by having an insulating layer, prevents heat generated within the intermediate layer A from dissipating (preventing heat diffusion), allowing the intermediate layer A to receive sufficient heat for heat-based peeling (particularly by melting or softening the adhesive in the intermediate layer A). Furthermore, the insulating layer of the adhesive tape of the present invention prevents heat generated within the intermediate layer A from being transferred to the adhered object, thus suppressing thermal degradation of the adhered object. In particular, when heating the adhesive or any molten or softened layer adjacent to the heating element by directly passing current through the heating element using resistance heating, even a small amount of energy can release the adhesive state within the intermediate layer A itself or at a desired location within the intermediate layer A, allowing for the removal of the bonded adhered objects. Moreover, when integrated into electronic devices, using the driving current within the electronic components to thermally peel off the adhesive tape prevents thermal degradation of the circuitry within the components, and heat-based peeling can be performed without the need for external devices, making the removal operation easier.

[0014] The adhesive tape of the present invention being "capable of being peeled off by heating" can refer to a method in which the adhesive tape becomes integral through heating and can be peeled off from the adhered object, or it can refer to a method in which peeling occurs within the adhesive tape, particularly within the intermediate layer A, or between the intermediate layer A and the layer adjacent to the intermediate layer A, thereby allowing a portion of the adhesive tape to be peeled off from the adhered object. Furthermore, when peeling off the adhesive tape by heating, the intermediate layer A can become integral and be peeled off from the adhered object, or a portion of the intermediate layer A can be peeled off from the adhered object.

[0015] <Intermediate Layer A> The aforementioned intermediate layer A includes at least a heating element and an adhesive, and may further include other components as needed. Intermediate layer A can be a single layer or multiple layers. Furthermore, intermediate layer A can be a layer with adhesiveness on both sides or a non-adhesive layer. The adhesiveness on both sides of intermediate layer A can refer to pressure-sensitive adhesiveness on both sides, heat-adhesiveness on both sides, or pressure-sensitive adhesiveness on one side and heat-adhesiveness on the other. When intermediate layer A has pressure-sensitive adhesiveness on both sides, it can easily bond to the adhered object and other layers constituting the adhesive tape of the present invention at room temperature, and can firmly bond before heating, therefore this is preferred.

[0016] <<Fever Body>> There are no particular limitations on the heating element used, and any known heating element can be appropriately selected depending on the heating method used. There are also no particular limitations on the heating method and heating means used, and any known heating means can be appropriately selected depending on the purpose. Examples include electromagnetic induction heating, infrared heating, microwave heating, heat conduction, and resistance heating. Among these, resistance heating is preferred because it allows for sufficient softening or melting of the adhesive (or any melt-softened layer) even with minimal energy; it allows for thermal disassembly of the adhesive tape using a drive current within an electronic component when integrated into an electronic device; it eliminates the need for heating the heating element via an external heat source through the adhered object; and it prevents overheating of the adhered object.

[0017] Here, "electromagnetic induction heating" refers to a non-contact heating method of electric heating, also known as high-frequency induction heating. If a resistive current-carrying body (heating element) is placed in the magnetic field generated by a coiled wire through which a high-frequency current (alternating current) flows, then according to the principle of electromagnetic induction, the current flows through the current-carrying body, heating it using Joule heat. "Resistance heating" refers to a type of electric heating method where a power source is connected to a resistive current-carrying body (heating element), allowing current to flow through it, and the current heats the current-carrying body using Joule heat. If current flows through the current-carrying body, the amount of Joule heat generated within a certain time is proportional to the square of the current and the resistance of the wire (Joule's law). The current-carrying body has an inherent resistivity (volume resistivity, etc.).

[0018] "Infrared heating" and "microwave heating" refer to non-contact heating methods that utilize electromagnetic waves in specific wavelength ranges, such as infrared and microwaves, and leverage radiation-based thermal energy. The atoms that make up a substance undergo thermal vibrations (molecular motion, crystal lattice vibrations) corresponding to the substance's own temperature. If electromagnetic waves of wavelengths corresponding to these vibration frequencies are absorbed, the molecular vibrations become more intense, generating heat. "Heat conduction" is a heating method that utilizes the phenomenon of heat transfer from a high-temperature side to a low-temperature side within a solid. It allows the heat source to directly contact a material with excellent thermal conductivity to transfer heat.

[0019] When the heating method is resistance heating, the preferred heating element is a current-carrying body with resistance, such as metals or non-metals. Examples of metals include nickel-chromium alloys (108 μΩ·cm); stainless steels such as SUS 410 (62.2 μΩ·cm), SUS304 (72.0 μΩ·cm), and SUS430 (60.0 μΩ·cm); titanium (55.0 μΩ·cm); and nickel silver (for example, 34.0 μΩ·cm in "Yangbai C7701" manufactured by Takeuchi Metal Foil Powder Industry Co., Ltd.). It should be noted that the values ​​in parentheses represent approximate volume resistivity of each material at 20°C. Examples of non-metals include carbon nanomaterials such as graphite, graphene, graphene oxide, carbon nanotubes, graphene plates, and carbon nanofibers (for example, 3352 μΩ·cm). Among these, nickel-chromium alloys and stainless steel are preferred from the viewpoints of being difficult to break when made into metal foils, easy to handle as tapes, and capable of melting or softening the adhesive layer in a short time to significantly reduce adhesive strength. Furthermore, carbon is preferred because it exhibits high volume resistivity, is easy to form into thin films, and is unlikely to compromise the required properties of the tape, such as conformability. Among these, carbon nanomaterials such as carbon nanotubes are preferred because their rod-like shape readily exhibits conductivity even in small quantities, enabling the adhesive layer A to melt or soften quickly through resistance heating.

[0020] The volume resistivity of the heating element when the heating method is resistance heating is preferably 30 μΩ·cm or more at room temperature (20°C), more preferably 50 μΩ·cm or more, even more preferably 70 μΩ·cm or more, and particularly preferably 100 μΩ·cm or more. Furthermore, there is no particular upper limit to the volume resistivity of the heating element, but if the volume resistivity is too high, a high voltage is required when energized. Therefore, it is preferably 100,000 μΩ·cm or less, more preferably 20,000 μΩ·cm or less, even 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 set in 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, and 100 μΩ·cm to 5,000 μΩ·cm. By making the volume resistivity of the heating element 30 μΩ·cm or higher, when using resistance heating to disassemble items, and in cases where the heating element is powered by the drive current of the electronic device connected to the wiring circuit within the electronic device, only the adhesive tape can be heated, preventing high-temperature degradation of the wiring circuit. In this case, the volume resistivity of the heating element is preferably higher than the volume resistivity of the wiring circuit within the electronic device.

[0021] The volume resistivity of the aforementioned heating element was measured at 20°C using a low resistivity meter (manufactured by Nitto Seiko Analytech Co., Ltd., trade name: "Loresta-AXMCT-T370") and a four-probe probe (manufactured by Nitto Seiko Analytech Co., Ltd., trade name: "ASP probe MCP-TP03P"), according to JIS K 7194. The measurement point was set to one point, and a correction factor of 4.532 was used for resistivity.

[0022] When the heating method is electromagnetic induction heating, the heating element is preferably a current-carrying body with resistance, such as iron, aluminum, nickel, stainless steel, zinc, lead, magnesium, and their metal oxides and alloys. Among these, aluminum and iron are more preferred.

[0023] When the heating method is either infrared heating or microwave heating, the heating element is preferably a material that absorbs a specific wavelength of infrared or microwave heating and undergoes thermal vibration (heat generation). Examples of such materials include organic and inorganic substances. Examples of such organic substances include resins, rubber, fibers, organic pigments, organic dyes, and organic pigments. The organic substance is preferably a component of the adhesive in the intermediate layer A. As for the inorganic substance, any material that generates heat when heated by infrared or microwaves is acceptable. Examples of such inorganic substances include metallic inorganic substances, non-metallic inorganic substances, inorganic pigments, inorganic dyes, and inorganic pigments. Examples of such metallic inorganic substances include non-ferrous metals such as aluminum, titanium, chromium, manganese, cobalt, nickel, magnesium, zinc, and copper; iron; and oxides of at least one of the aforementioned non-ferrous metals and iron. Examples of such non-metallic inorganic substances include silicon, carbon; and oxides of silicon dioxide (e.g., SiO2).

[0024] When the heating method is heat conduction, the preferred heating element is a material with excellent thermal conductivity, such as metals or non-metals. Examples of metals include aluminum, iron, copper, oxides of these metals, and nitrides. Examples of non-metals include silicon carbide ceramics and graphite.

[0025] When the heating method is resistance heating, there are no particular restrictions on the shape of the heating element, as long as it is a shape that allows resistance heating to occur through electrical contact between the heating elements. It can be appropriately selected according to the purpose; for example, sheet-like, mesh-like, granular, and fibrous shapes are possible. Among these, a sheet-like shape is preferred from the perspective of ensuring sufficient adhesion between other layers that can contact the heating element before energization, and minimizing the risk of damage or wire breakage to the heating element itself when disassembling it after energization due to heat generation on the surface. Examples of sheet-like heating elements include: metal foil containing the aforementioned metal, sheets containing the aforementioned non-metal, resin sheets with high-density dispersion of particles or fibers containing the aforementioned metal or non-metal, coatings containing the aforementioned metal or non-metal, sheets impregnated with the aforementioned metal or non-metal in nonwoven fabric, and nonwoven fabrics containing the aforementioned metal or non-metal. Even among these planar heating elements, from the perspective of being able to heat the entire surface through high volume resistance and not easily broken, metal foil, non-metallic sheet, metallic or non-metallic coating, or metallic or non-metallic nonwoven fabric are more preferred, and metal foil is even more preferred.

[0026] The planar heating element can cover the entire surface of the adhesive layer or only a portion of it in a top view of the adhesive tape. Furthermore, the planar heating element can be patterned, or it can be a strip or line. If the heating element is a strip or line, the heating efficiency is high, and the contact area with the adhered object is small, thus offering advantages in terms of ease of peeling. In this case, the length (strip width or line width) of the heating element along its minor axis is preferably 0.5 mm to 20 mm, more preferably 1 mm to 10 mm, and even more preferably 2 mm to 5 mm.

[0027] Furthermore, if the planar heating element is patterned (has a patterned shape), the distance between the terminals (terminals for connection to the power supply) of the heating element can be increased, thereby increasing the resistance. Therefore, the heating efficiency of the planar heating element is higher, and the adhesive tape of the present invention can be peeled off in a short time. In the case where the planar heating element is patterned, the line width of the pattern is not particularly limited and can be within the same preferred range as the tape width or line width described above.

[0028] In planar heating elements, the heating element can be disposed on one or both sides of the substrate. When the heating element is disposed on one or both sides of the substrate, it can be configured to cover the entire area of ​​one or both sides of the substrate, or it can be configured as a line, strip, or pattern. When the planar heating element is disposed on one or both sides of the substrate, it is configured to be in direct contact with one or both sides of the substrate. As for the substrate, there are no particular limitations as long as it can support the heating element; from the viewpoints of adhesive tape conformability and thin film formation, a resin film is preferred. Examples of resin films that can be used include 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) film. Alternatively, a resin film used for the melt softening layer described later can also be used.

[0029] Examples of mesh-like heating elements include integrally formed heating elements such as heating elements with multiple through holes on the surface-shaped heating element, mesh-like or grid-like heating elements, etc.

[0030] Furthermore, even if the heating element is not integrally formed, as long as the heating elements can make electrical contact with each other, it can be, for example, particles or fibers containing the aforementioned metal or non-metal. By dispersing granular or fibrous heating elements in the adhesive, even if the heating elements are not integrally formed, as long as electrical contact between the heating elements can be formed, it is acceptable. When the particles or fibers containing the heating element are dispersed in the adhesive, there is no particular limitation on the content of the particles or fibers, as long as electrical contact between the heating elements can be formed, and it can be appropriately selected according to the purpose. Relative to the total amount of the adhesive, it is preferably 20% to 95% by mass, more preferably 40% to 90% by mass. When the intermediate layer A is a single layer formed by the adhesive and the single layer contains the heating element, the content of particles or fibers can be set to the content relative to the total amount of intermediate layer A. In addition, when the intermediate layer A is a laminate, and one of the layers constituting the laminate has an adhesive layer a in which particles or fibers of the heating element are dispersed, the content of particles or fibers can be set to the content relative to the total amount of one adhesive layer a.

[0031] The average thickness of the planar heating element is not particularly limited and can be appropriately selected according to the purpose. Preferably, it is 1μm to 200μm, more preferably 2μm to 200μm, more preferably 3μm to 150μm, more preferably 5μm to 150μm, more preferably 5μm to 100μm, even more preferably 10μm to 100μm, and most preferably 10μm to 50μm. The average thickness of the planar heating element is the average value obtained by measuring the thickness at five or more randomly selected locations. The greater the average thickness of the planar heating element, the greater the current flow and the heat generation; however, from the viewpoint of the adhesive tape's followability and adhesion, the thickness is limited. Conversely, if the average thickness of the planar heating element is within the aforementioned range, sufficient current flow and heat generation can be obtained, the heating element can be effectively heated by resistance heating, and excellent adhesive tape followability and adhesion can be achieved.

[0032] 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. When the heating element is formed on both sides of the resin film, it refers to the thickness of the heating element on each single side.

[0033] As the heating element mentioned above, a suitably manufactured heating element or a commercially available product can be used. As for the aforementioned commercially available products, there are no particular restrictions, and appropriate selections can be made according to the purpose. For example, nickel-chromium alloy foils such as NCH1-H; stainless steel foils such as SUS304-H and SUS430-H; titanium foils such as TR270C-H; and nickel silver such as C7701 (all of which are manufactured by Takeuchi Metal Foil Powder Industry Co., Ltd.) can be used as surface heating elements. In addition, heating elements formed by patterning these materials can also be used.

[0034] When the heating method is either electromagnetic induction heating or heat conduction, the shape of the heating element is not particularly limited and can be appropriately selected according to the purpose. For example, it can be planar, mesh-like, or a shape in which particles or fibers containing the heating element are dispersed in the adhesive. When the heating method is electromagnetic induction heating or heat conduction, the planar heating element can cover the entire surface of the adhesive layer or only a part of it. Furthermore, it can be patterned, strip-shaped, or linear. If the heating element is strip-shaped or linear, the heating efficiency is high, and the contact area with the adhered object is small, thus improving ease of peeling. In this case, the length (strip width or line width) of the heating element along its minor axis is preferably 1 mm to 10 mm, more preferably 2 mm to 5 mm. The average thickness of the planar heating element is not particularly limited and can be appropriately selected according to the purpose. It is preferably 5 μm to 200 μm, more preferably 10 μm to 150 μm, and even more preferably 12 μm to 100 μm.

[0035] When the heating method is either infrared heating or microwave heating, the heating element is preferably dispersed in the adhesive or in the melt-softening layer described later, and more preferably is a component of the adhesive in the intermediate layer A. When the heating method is infrared heating, pigments or the like can be used as infrared absorbing materials, which can be dispersed in the adhesive or resin, or a thin film coating can be applied to the intermediate layer A, which is a laminate.

[0036] <<Adhesives>> There are no particular limitations on the adhesive used, and it can be appropriately selected according to the purpose, but at least one of pressure-sensitive adhesive and hot-melt adhesive is preferred. By setting the adhesive included in the intermediate layer A as a hot-melt adhesive or a pressure-sensitive adhesive containing a thermoplastic resin, the resin can melt or soften due to heat. Therefore, it is advantageous that it can be peeled off even without the presence of components that cause the initiation of peeling at the adhesive interface, such as heating foaming agents, or components that cause a decrease in adhesive strength. In addition, the adhesive is preferably one that has a softening point, which is advantageous because it becomes rapidly softer by reaching a temperature higher than the softening point and exhibits high deformability and fluidity.

[0037] The adhesive described above melts or softens the resin by heating, resulting in a lower adhesive strength during heating compared to that at room temperature.

[0038] The storage modulus G of the aforementioned adhesive (the adhesive layer formed by the aforementioned adhesive), measured using dynamic viscoelastic spectra at 1 Hz and 23 °C. 23 From the viewpoint of ensuring good fixation of the adhered objects to each other under normal conditions, a 1.0 × 10⁻⁶ ohmmeter is preferred. 3 Pa ~ 1.0 × 109 Pa, preferably 1.0 × 10 Pa. 3 Pa ~ 5.0 × 10 7 Pa, more preferably 5.0 × 10 Pa. 3 Pa ~ 5.0 × 10 7 Pa, more preferably 5.0 × 10 Pa. 3 Pa ~ 5.0 × 10 6 Pa, preferably 5.0 × 10 Pa. 3 Pa ~ 1.0 × 10 6 Pa.

[0039] In the case where the adhesive is a pressure-sensitive adhesive (adhesive), the storage modulus G of the pressure-sensitive adhesive (pressure-sensitive adhesive layer) is determined by dynamic viscoelastic spectroscopy at 1 Hz and 23 °C. 23 From the viewpoint of ensuring that the adhered objects are well fixed together under normal conditions (unheated state), the aforementioned storage modulus G 23 Within the range, 1.0 × 10 is preferred. 3 Pa ~ 5.0 × 10 7 Pa, more preferably 5.0 × 10 Pa. 3 Pa ~ 5.0 × 10 6 Pa, more preferably 5.0 × 10 Pa. 3 Pa ~ 1.0 × 10 6 Pa.

[0040] Furthermore, when the aforementioned adhesive is a hot melt adhesive, the storage modulus G of the aforementioned hot melt adhesive (hot melt adhesive layer) is determined using dynamic viscoelastic spectra at 1 Hz and 23 °C. 23 From the viewpoint of ensuring good adhesion between the adhered objects under normal conditions (unheated state), a density of 1.0 × 10⁻⁶ is preferred. 3 Pa ~ 1.0 × 10 9 Pa, more preferably 5.0 × 10 Pa. 3 Pa ~ 5.0 × 10 8 Pa, more preferably 1.0 × 10 Pa. 4 Pa ~ 1.0 × 10 8 Pa.

[0041] The storage modulus G of the aforementioned adhesive (the adhesive layer formed by the aforementioned adhesive) was determined by dynamic viscoelastic spectroscopy at 1 Hz and 100 °C. 100 From the viewpoint that heating makes it easier to separate the adhered materials from each other, 1.0 × 10⁻⁶ is preferred. 0 Pa ~ 5.0 × 10 6 Pa, preferably 1.0 × 10 3 Pa ~ 1.0 × 106 Pa, more preferably 1.0 × 10 Pa 3 Pa ~ 1.0 × 10 6 Pa, more preferably 5.0 × 10 Pa. 3 Pa ~ 5.0 × 10 5 Pa.

[0042] In the case where the adhesive is a pressure-sensitive adhesive (adhesive), the storage modulus G of the pressure-sensitive adhesive (pressure-sensitive adhesive layer) is determined by dynamic viscoelastic spectroscopy at 1 Hz and 100 °C. 100 In the aforementioned energy storage modulus G 100 Within the range, 1.0 × 10 is preferred. 2 Pa ~ 5.0 × 10 6 Within the range of Pa, 1.0 × 10 Pa is more preferred. 3 Pa ~ 1.0 × 10 6 Within the range of Pa, it is further preferred to be 5.0 × 10 Pa. 3 Pa ~ 5.0 × 10 5 Within the range of Pa. This is because, by measuring the storage modulus G of the aforementioned pressure-sensitive adhesive (pressure-sensitive adhesive layer)... 100 Within the aforementioned range, pressure-sensitive adhesives can be melted or softened by heating in a short time, thereby allowing them to be peeled off.

[0043] When the adhesive is a pressure-sensitive adhesive, the above storage modulus G 23 and energy storage modulus G 100 The following method can be used to determine the energy modulus. Using a viscoelasticity testing machine (ARES-G2, manufactured by TA Instruments Japan), a test piece is sandwiched between parallel discs with a diameter of 8 mm, which serve as the measuring section of the machine. The storage modulus G′ is measured at a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a heating rate of 2°C / min. The values ​​at 23°C and 100°C are recorded. The test piece uses the following pressure-sensitive adhesive layer (adhesive layer): the pressure-sensitive adhesive is applied using a coater to a dry thickness of approximately 2 mm and dried, and then cured as needed.

[0044] Furthermore, when the adhesive is a hot melt adhesive, the aforementioned storage modulus G 23 and energy storage modulus G 100 The test piece is clamped between the tensile testing fixtures of the measuring section of a viscoelasticity testing machine, and the storage modulus G′ is measured under the conditions of a frequency of 1 Hz, a temperature range of -40℃ to 200℃, and a heating rate of 2℃ / min. The values ​​are recorded at 23℃ and 100℃. The test piece is formed using a hot melt adhesive layer: a hot melt adhesive is applied using an applicator to a thickness of approximately 0.1 mm after drying, and then dried.

[0045] The temperature at which the loss tangent (tanδ) of the adhesive (the adhesive layer formed by the adhesive) reaches 0.45 or more is preferably in a temperature range of 80°C or higher and 200°C or lower. The temperature at which the loss tangent (tanδ) reaches 0.8 or higher is more preferably in a temperature range of 80°C or higher and 200°C or lower. The temperature at which the loss tangent (tanδ) reaches 1.0 or higher is even more preferably in a temperature range of 80°C or higher and 200°C or lower.

[0046] By ensuring that the temperature at which the tanδ of the adhesive (the adhesive layer formed by the adhesive) reaches a specific value exists in a temperature range of 80°C or higher and 200°C or lower, the adhesive, when heated to this temperature by a heat source, is prone to plastic deformation due to melting or softening. This facilitates easier peeling and disassembly in a shorter time by utilizing the cohesive breakdown within the layer formed by the adhesive. As will be described later, when the intermediate layer A has an adhesive layer a1 and an adhesive layer a2, it is preferable that at least one of the adhesive layers a1 and a2 exists in a temperature range of 80°C or higher and 200°C where the loss tangent (tanδ) reaches 0.45 or higher.

[0047] It should be noted that the loss tangent (tanδ) is calculated using the formula tanδ = G″ / G′, based on the storage modulus (G′) and loss modulus (G″) obtained from the dynamic viscoelasticity determination based on temperature dispersion. The dynamic viscoelasticity determination and the aforementioned storage modulus G... 23 and energy storage modulus G 100 The determination method is the same.

[0048] Storage modulus G of adhesive (adhesive layer) 23 Energy storage modulus G 100 The loss tangent (tanδ) can be adjusted by modifying the types and combinations of monomers in the resin (base polymer) that constitutes the main component of the adhesive, the proportions of each monomer, the amount of tackifying resin added as needed, and the amount of crosslinking agent added as needed (gel fraction of the adhesive). The resin (base polymer) that constitutes the main component of the adhesive can be used alone or in combination of two or more. The resin that constitutes the main component of the adhesive will be explained in the "-Resin-" section below. Furthermore, when the adhesive layer contains a heating element, the storage modulus G of the adhesive (adhesive layer)... 23 Energy storage modulus G 100 And the loss tangent (tanδ) is set to the value of the adhesive (adhesive layer) excluding the heating element.

[0049] The melting point of the aforementioned adhesive is preferably 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. This is because by setting the melting point of the adhesive within the above range, it can exhibit high adhesive strength before heating, and the adhesive can easily melt or soften even with a small amount of heating. The melting point of the aforementioned adhesive can be adjusted by selecting the type of resin as the main component of the adhesive, the content of tackifying resin in the adhesive, the gel fraction, etc. The melting point of the aforementioned adhesive can be set as the temperature of the endothermic peak accompanying melting, as measured using differential scanning calorimetry (DSC).

[0050] <<<Pressure-sensitive adhesives>>> The aforementioned pressure-sensitive adhesive refers to an adhesive that bonds by applying pressure for a short time at room temperature. Pressure-sensitive adhesives are also called adhesives. The aforementioned pressure-sensitive adhesive is viscous at room temperature. There are no particular limitations on the aforementioned pressure-sensitive adhesive; any known pressure-sensitive adhesive can be appropriately selected according to the purpose. Examples include: acrylic-based pressure-sensitive adhesives (acrylic adhesives), urethane-based pressure-sensitive adhesives (urethane adhesives), synthetic rubber-based pressure-sensitive adhesives, natural rubber-based pressure-sensitive adhesives, and other rubber-based pressure-sensitive adhesives (rubber adhesives), silicone-based pressure-sensitive adhesives (silicone adhesives), etc.

[0051] The aforementioned pressure-sensitive adhesive may contain a thermoplastic resin or may contain a non-thermoplastic resin instead of a thermoplastic resin. When the pressure-sensitive adhesive contains a thermoplastic resin, heating it melts or softens the adhesive, thereby reducing its adhesive strength and allowing the intermediate layer A to peel off. When the pressure-sensitive adhesive contains a non-thermoplastic resin instead of a thermoplastic resin, it is used in conjunction with at least one of the aforementioned hot-melt adhesive and the melt-softened layer; the hot-melt adhesive or the melt-softened layer melts upon heating, allowing the intermediate layer A to peel off.

[0052] As described above, the acrylic-based pressure-sensitive adhesive includes acrylic resin, and further includes, as needed, other components such as tackifying resin, crosslinking agent, and antioxidant. As described above, the urethane-based pressure-sensitive adhesive includes urethane resin, and further includes, as needed, other components such as tackifying resin, crosslinking agent, and antioxidant. As described above, the rubber-based pressure-sensitive adhesive includes rubber materials such as styrene resin, and further includes, as needed, other components such as tackifying resin, crosslinking agent, and antioxidant. As described above, the silicone-based pressure-sensitive adhesive includes silicone resin, and further includes, as needed, other components such as tackifying resin, crosslinking agent, and antioxidant.

[0053] <<<Hot Melt Adhesives>>> The aforementioned hot melt adhesive refers to a thermoplastic adhesive that is solid at room temperature but melts upon heating, liquefies, is applied to the substrates, and solidifies upon cooling to form a bond. This hot melt adhesive can be dissolved in a solvent for coating, cured by drying to form a film, and bonded by applying heat when adhering to the substrates. This hot melt adhesive typically has no tackiness at room temperature or has lower tackiness than pressure-sensitive adhesives. The hot melt adhesive contains a thermoplastic resin and, if necessary, other components such as tackifying resins, crosslinking agents, and antioxidants.

[0054] Examples of the aforementioned hot melt adhesives 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 with styrene-based thermoplastic elastomers as their base.

[0055] -Resin- Examples of resins (base polymers) that can be used as the main component of the aforementioned pressure-sensitive adhesives and hot-melt adhesives 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; acrylic resins such as polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate (PMMA), polyethyl methacrylate, and acrylic polymers formed by polymerizing one or more (meth)acrylic acid monomers; polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polypropylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate; and nylon. Polyamide resins such as Long (registered trademark); 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 resins; cellulose resins such as nitrocellulose and cellulose acetate; silicone resins; thermoplastic resins such as fluorinated resins; 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 can be used individually or in combination with two or more.

[0056] Among these, thermoplastic resins are preferred, more preferably acrylic resins, urethane resins, polyester resins, styrene thermoplastic elastomers, olefin thermoplastic elastomers, vinyl chloride thermoplastic elastomers, acrylic thermoplastic elastomers, ester thermoplastic elastomers, urethane thermoplastic elastomers, amide thermoplastic elastomers, and other thermoplastic elastomers, with styrene thermoplastic elastomers being particularly preferred.

[0057] Examples of the aforementioned styrene thermoplastic elastomers include: styrene-ethylene-butene copolymers (SEB) and other styrene-based AB-type diblock copolymers; styrene-butadiene-styrene copolymers (SBS), hydrides of SBS (styrene-ethylene-butene-styrene copolymer (SEBS)), styrene-isoprene-styrene copolymers (SIS), hydrides of SIS (styrene-ethylene-propylene-styrene copolymer (SEPS)), styrene-isobutylene-styrene copolymers (SIBS) and other styrene-based ABA-type triblock copolymers; styrene-butadiene-styrene-butadiene copolymers (SBSB) and other styrene-based ABAB-type tetrablock copolymers; styrene-butadiene-styrene-butadiene copolymers (SBSBS) and other styrene-based ABABA-type pentablock copolymers; styrene-based multiblock copolymers having more than one AB repeating unit; hydrides formed by hydrogenating the ethylene double bonds of styrene-based random copolymers such as styrene-butadiene rubber (SBR); etc. They can be used individually or in combination of two or more. Commercially available products can be used as the aforementioned styrene-based thermoplastic elastomers.

[0058] 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 setting it within the above range, it is easy to adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired range, and it becomes easier to melt or soften the adhesive by heating. The method for determining the weight-average molecular weight can be the same as the method for determining the weight-average molecular weight of acrylic polymers described later.

[0059] The aforementioned thermoplastic elastomer can be one or more triblock copolymers, one or more diblock copolymers, or a mixture of triblock copolymers and diblock copolymers. Preferably, the thermoplastic elastomer contains at least a diblock copolymer because the adhesive exhibits moderate cohesiveness, good adhesion at room temperature before heating, and easy melting or softening upon heating. 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 further preferably in the range of 20% to 75% by mass, from the perspective of an excellent balance between adhesion at room temperature and melting or softening upon heating.

[0060] Furthermore, the thermoplastic resin used as the main component of the adhesive is preferably a polyester resin. It can be a crystalline polyester resin or a non-crystalline polyester resin.

[0061] Furthermore, acrylic resin is preferred as the main thermoplastic resin used as the adhesive. As the aforementioned acrylic resin, an acrylic polymer obtained by polymerizing a monomer component containing a (meth)acrylate monomer can be used. The acrylic polymer can be a homopolymer of the (meth)acrylate monomer or a copolymer with the (meth)acrylate monomer and other monomers. Copolymers are preferred. It should be noted that (meth)acrylate refers to acrylic acid or methacrylic acid. (Meth)acrylate refers to acrylate or methacrylate.

[0062] Examples of (meth)acrylate monomers constituting acrylic polymers include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, isononyl methacrylate, isodecanyl methacrylate, lauryl methacrylate, and other (meth)acrylate monomers with 1 to 14 carbon atoms. Preferably, the monomer comprises an alkyl (meth)acrylate monomer having an alkyl chain having 1 to 9 carbon atoms; more preferably, it comprises an alkyl (meth)acrylate monomer having an alkyl chain having 2 to 9 carbon atoms. From the perspective of easily adjusting the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired range, it is further preferred to include an alkyl (meth)acrylate monomer having an alkyl chain having 4 to 9 carbon atoms; more preferably, it comprises an alkyl acrylate monomer having an alkyl chain having 4 to 9 carbon atoms. Examples of the aforementioned alkyl acrylate monomers having an alkyl chain having 4 to 9 carbon atoms include n-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, and isononyl acrylate. The acrylic polymer preferably contains one or more of the groups selected from these monomers in its structural unit.

[0063] In the total amount of monomer components constituting the above-mentioned acrylic polymer, the content of the above-mentioned (meth)acrylate monomer is preferably in the range of 70% to 99.9% by mass, more preferably in the range of 80% to 99% by mass, and even more preferably in the range of 90% to 97% by mass, since it is easy to adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired range.

[0064] In the aforementioned acrylic polymers, the (meth)acrylic acid monomer, in addition to the aforementioned (meth)acrylate monomers, is preferably a (meth)acrylic acid monomer that includes a polar group in its structural unit. Examples of polar groups include hydroxyl, carboxyl, amide, and other polar groups.

[0065] Examples of hydroxyl-containing (meth)acrylate monomers include, for example, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, hydroxypropyl (meth)acrylate, caprolactone-modified (meth)acrylate, polyethylene glycol mono(meth)acrylate, and polypropylene glycol mono(meth)acrylate. Among these, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate are preferred.

[0066] Examples of (meth)acrylic acid monomers having a carboxyl group include: acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, dimers of acrylic acid or methacrylic acid, and ethylene oxide-modified succinic acid acrylates. Among these, acrylic acid is preferred.

[0067] Examples of (meth)acrylic acid monomers having an amide group include, for example, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, acrylmorpholine, acrylamide, N,N-dimethylacrylamide, and 2-(perhydrogenated phthalimide-N-yl)ethyl acrylate. Among these, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, and acrylmorpholine are preferred.

[0068] Examples of vinyl monomers having the other polar groups mentioned above include vinyl acetate, acrylonitrile, maleic anhydride, and itaconic anhydride.

[0069] Among (meth)acrylic acid monomers having polar groups, at least one of (meth)acrylic acid monomers having hydroxyl groups and (meth)acrylic acid monomers having carboxyl groups is preferred. This is because, when used with the crosslinking agent described later, a crosslinked structure can be formed between the hydroxyl groups, the carboxyl groups and the crosslinking agent, and the storage modulus of the adhesive (adhesive layer) can be adjusted.

[0070] In the total amount of monomer components constituting the above-mentioned acrylic polymer, the content of (meth)acrylic acid monomers having polar groups is preferably in the range of 0.1% to 20% by mass, more preferably in the range of 1% to 13% by mass, and more preferably in the range of 1.5% to 8% by mass, since it is easy to adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired range.

[0071] The weight-average molecular weight of the acrylic polymer is preferably 400,000 to 1,400,000, more preferably 600,000 to 1,200,000, and preferably 650,000 to 1,100,000 in order to easily adjust the storage modulus and loss tangent of the adhesive (adhesive layer) to the desired range.

[0072] Weight-average molecular weight can be determined by gel permeation chromatography (GPC). More specifically, the GPC measuring instrument can be the "SC8020" manufactured by Tosoh Corporation, which determines the weight-average molecular weight by measuring the polystyrene equivalent under the following GPC measuring conditions. (GPC determination conditions) • Sample concentration: 0.5% by mass (tetrahydrofuran solution) • Sample injection volume: 100 μL • Eluent: Tetrahydrofuran (THF) • Flow rate: 1.0 mL / min • Column temperature (measurement temperature): 40℃ ·Pillar: "TSKgel GMHHR-H" manufactured by Tosoh Corporation • Detector: Differential Refraction

[0073] The resin content, as the main component of the aforementioned adhesive, is preferably 50% by mass or more out of 100% by mass of the total solid content of the adhesive, more preferably 70% by mass or more, further preferably 90% by mass or more, more preferably 98% by mass or more, and even more preferably 99% by mass or more. It should be noted that when the adhesive includes the aforementioned heating element, this refers to the content percentage in the total solid content of the adhesive excluding the heating element.

[0074] Furthermore, when the adhesive, in addition to the resin as the main component, also includes the tackifying resin described later, the total proportion of the main component resin and the tackifying resin is preferably 50% by mass or more in 100% by mass of the total solid components of the adhesive, more preferably 70% by mass or more, further preferably 90% by mass or more, more preferably 98% by mass or more, and even more preferably 99% by mass or more. It should be noted that when the adhesive includes the aforementioned heating element, this refers to the proportion in the total solid components of the adhesive excluding the heating element.

[0075] -Other ingredients- Other components that can be used in the aforementioned pressure-sensitive adhesives and hot-melt adhesives include, for example: tackifying resins, crosslinking agents, antioxidants, thermally expandable fillers, solvents, infrared absorbers, ultraviolet absorbers, fillers; glass and plastic fibers; fillers such as balls, beads, and metal powders; pigments, thickeners, etc.

[0076] The aforementioned pressure-sensitive adhesives and hot-melt adhesives can be thermofoaming types that can foam and / or expand upon heating, and preferably non-thermally foaming types that do not foam and / or expand upon heating. Even without the presence of thermally expandable fillers, foaming agents, or other components that foam and / or expand within the adhesive layer (expansion-promoting components), peeling is possible through the melting or softening of the resin contained in the adhesive. Furthermore, by using a non-thermally foaming adhesive layer constituting the intermediate layer, malfunctions of articles and components caused by gases generated through foaming, and damage to articles and components caused by pressure applied to the adhered objects through expansion, can be suppressed. Moreover, in the case of a thermofoaming adhesive layer, after long-term use in articles and components, there may be instances where the foaming agent, etc., may be modified, deactivated, or released to the outside, resulting in no foaming upon disassembly. However, by using a non-thermally foaming adhesive layer, reliable disassembly is possible even after long-term use in articles and components. An adhesive that does not contain foaming and / or swelling components (swelling performance components) means that the content of the adhesive in 1 part by weight relative to 100 parts by weight of the base polymer is less than 1 part by weight.

[0077] --Tackifying Resin-- In the above-mentioned adhesives, a tackifying resin can be used to adjust the strong adhesion of the resulting adhesive layer. There are no particular limitations on the tackifying resin used; it can be appropriately selected according to the purpose. Examples include: rosin-based tackifying resins, polymerized rosin-based tackifying resins, polymerized rosin ester-based tackifying resins, rosin phenolic 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 phenolic tackifying resins, aliphatic (petroleum resin)-based tackifying resins, C5 / C9 petroleum-based tackifying resins, and (meth)acrylate-based tackifying resins.

[0078] In addition to the aforementioned tackifying resin, tackifying resins that are liquid at room temperature can also be used. Examples of such liquid tackifying resins include processing oils, polyester-based tackifying resins, and low molecular weight liquid rubbers such as polybutene.

[0079] The content of the tackifying resin in the adhesive is preferably in the range of 1 to 150 parts by weight relative to 100 parts by weight of the base polymer, with a focus on ensuring good adhesion of the adhesive at room temperature and enabling it to exhibit heat durability. More preferably, it is in the range of 10 to 150 parts by weight, even more preferably in the range of 15 to 100 parts by weight, and even more preferably in the range of 50 to 100 parts by weight.

[0080] --Cross-linking agent-- In the above-mentioned adhesives, a crosslinking agent can be used to improve the cohesiveness of the resulting adhesive layer. There are no particular limitations on the crosslinking agent used; it can be appropriately selected according to the purpose. Examples include: isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, polyvalent metal salt-based crosslinking agents, metal chelate-based crosslinking agents, ketone-hydrazide-based crosslinking agents, oxazoline-based crosslinking agents, carbodiimide-based crosslinking agents, silane-based crosslinking agents, and glycidyl (alkoxy)epoxysilane-based crosslinking agents.

[0081] The content of the crosslinking agent contained in the above adhesive can be set to a range in which the adhesive becomes the gel fraction described later, and can be appropriately set.

[0082] --Antioxidants-- There are no particular limitations on the antioxidants mentioned above, and they can be appropriately selected according to the purpose. For example, phenolic antioxidants, amine antioxidants, and carbodiimide antioxidants can be cited.

[0083] --Solvent-- There are no particular limitations on the solvents used in the adhesive composition. Solvents commonly used in adhesive compositions can be appropriately selected according to the purpose. Examples include organic solvents such as toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, and hexane; and water or aqueous solvents with water as the main component. It should be noted that the adhesive layer typically does not contain solvents, but residual solvents may be present.

[0084] -Adhesive- When the adhesive comprises the resin and crosslinking agent as the main components, it is preferable that the adhesive has a gel fraction of 0% to 80% by mass, which allows it to melt and / or soften sufficiently even with a short heating time. Within the aforementioned range, from the perspective of good initial tackiness of the adhesive layer and good holding power even at high temperatures, the gel fraction is more preferably 10% to 65% by mass, and even more preferably 15% to 55% by mass. Particularly when the adhesive is a pressure-sensitive adhesive, the aforementioned gel fraction range is preferred. On the other hand, within the aforementioned range, from the perspective of good removability through heating, the aforementioned gel fraction is more preferably 0% to 60% by mass, and even more preferably 0% to 40% by mass. Among these, when the adhesive is a hot-melt adhesive, the aforementioned gel fraction range is preferred.

[0085] The gel fraction of an adhesive is the percentage of the dried mass of the remaining insoluble components after the adhesive coating has been immersed in toluene for 24 hours. The gel fraction can be adjusted by adjusting the amount of crosslinking agent, etc.

[0086] [The structure of intermediate layer A] The intermediate layer A in the aforementioned adhesive tape can be a layer with adhesive properties on both sides, or it can be a layer without adhesive properties. Preferably, the intermediate layer A is a layer with pressure-sensitive adhesive and / or heat-adhesive properties on both sides. This is because it can be easily bonded to other layers constituting the insulating layer or other adhesive tapes. Furthermore, the intermediate layer A can be a single layer or can comprise multiple layers.

[0087] It should be noted that when the intermediate layer A is a laminate, sometimes the adhesive layers a1 and a2 constituting the intermediate layer A are collectively referred to as adhesive layer a, and sometimes the melt-softening layers c1 and c2 are collectively referred to as melt-softening layer c. Adhesive layer a, heating element b, and melt-softening layer c will be described in detail later.

[0088] The intermediate layer A of the adhesive tape described above will be described below using the accompanying drawings. The adhesive layers B1 and B2 and the insulation layer C of the adhesive tape will be described separately.

[0089] [First Method] In the case where the aforementioned intermediate layer A comprises multiple layers, the intermediate layer A in the adhesive tape 10 is, for example, as shown in the example... Figure 1A and Figure 1B As shown, the intermediate layer A can be a laminate containing a planar heating element b, adhesive layers a1 and a2 on each surface of the heating element, and the layers are stacked sequentially as adhesive layer a1 / heating element b / adhesive layer a2. Specifically, in the first embodiment, the intermediate layer A is a laminate containing the heating element b, adhesive layer a1 in contact with one side of the heating element b, and adhesive layer a2 in contact with the other side of the heating element b. Adhesive layers a1 and a2 can have the same composition or different compositions. At least one of adhesive layers a1 and a2 can be softened or melted by heating, or both adhesive layers a1 and a2 can be softened or melted by heating. When at least one of the adhesive layers a1 and a2 in contact with the heating element b is melted or softened by heating, the adhesive force decreases, and the intermediate layer A can be peeled off.

[0090] Preferably, adhesive layers a1 and a2 have different compositions. By forming adhesive layers a1 and a2 with different adhesives, it is possible to change the tendency of the storage modulus and loss tangent (tanδ). Even if adhesive layers a1 and a2 can be softened or melted by heating, it is advantageous to adjust the temperature and peeling position during disassembly based on the differences in the physical properties of adhesive layers a1 and a2.

[0091] In the adhesive layer A of the first method, the details of the adhesive forming adhesive layer a are the same as those described in the aforementioned "<<Adhesive>>" section.

[0092] At least one of the aforementioned adhesive layers a1 and a2 is preferably a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive, and more preferably, both adhesive layers a1 and a2 are pressure-sensitive adhesive layers. The pressure-sensitive adhesive layer is viscous at room temperature, therefore, adhesive layer a1 and / or adhesive layer a2, as pressure-sensitive adhesive layers, can be easily bonded to other layers constituting the adhesive tape, such as the insulation layer.

[0093] Furthermore, at least one of the aforementioned adhesive layers a1 and a2 may be a hot-melt adhesive layer formed of a hot-melt adhesive, and both adhesive layers a1 and a2 may also be hot-melt adhesive layers. Hot-melt adhesives exhibit adhesive properties upon heating; therefore, adhesive layers a1 and / or a2, as hot-melt adhesive layers, can be easily bonded to other layers constituting the adhesive tape, such as the insulation layer, upon heating.

[0094] 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.

[0095] In the first embodiment, the intermediate layer A is preferably, in a top view, the planar heating element b has a pair of protrusions e extending from the outer peripheries of the adhesive layer a1 and the adhesive layer a2 (see reference). Figure 1C and D). There can be two or more protrusions e, and their positions within the heating element are not particularly limited and can be appropriately selected according to the purpose. The two protrusions e can be located on the same side of the outer periphery of the adhesive layers a1 and a2 (see reference). Figure 1D (1)~(3)) can also be located on different sides (see reference) Figure 1C , Figure 1D (4)~(6)).

[0096] The protrusion e is preferably located on opposite sides of the outer periphery of adhesive layers a1 and a2, respectively (see reference). Figure 1D (4)~(6)) are preferably located on approximately diagonal lines on the outer periphery of adhesive layers a1 and a2, respectively (see reference). Figure 1D (2)~(7)). Thus, current can flow through the entire area of ​​the planar heating element b, which can further improve the heating efficiency. Furthermore, when the protrusion e is located on the same side of the outer periphery of adhesive layers a1 and a2, the heating element b is preferably shaped like a ko, a serrated shape, etc. in the top view (see reference). Figure 1D (1)~(4), (8)), as long as the heating element can uniformly heat the surfaces of adhesive layers a1 and a2, then adjacent parts located on the same side can also be heated (see reference). Figure 1D (3), (8)). Thus, the current can flow through the entire area of ​​the planar heating element b, which can further improve the heating efficiency.

[0097] Additionally, the protruding part e can be in three or more locations (see reference). Figure 1D (9) Alternatively, the desired pair (two locations) can be selected to energize the heating element. The pair of protrusions e of the heating element b function as a pair of terminals for electrical connection to the power source in the disassembly method of the article described later, and can be easily energized to the heating element b.

[0098] The length of the protrusions is preferably 1mm to 50mm, more preferably 2mm to 25mm, from the perspective of facilitating contact with power sources and heat sources. Each protrusion can be bent in a direction different from the direction of the adhesive tape. For example, when the objects to be bonded together are in a state of being glued together, the protrusions can be bent and tucked in a direction perpendicular to the direction of the adhesive tape. When it is time to remove the objects from the adhesive tape (during disassembly), the protrusions can be bent again in the direction of the adhesive tape, so that the protrusions come into contact with power sources and heat sources.

[0099] When the aforementioned intermediate layer A is a multi-layered laminate, the average thickness of each of the adhesive layers a1 and a2 is not particularly limited and can be appropriately selected according to the purpose. Preferably, it is 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 later can also be set to the same specification. When the aforementioned intermediate layer A is a multi-layered laminate, the total thickness of the aforementioned intermediate layer A is not particularly limited and can be appropriately selected according to the purpose. Preferably, it is 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 intermediate layer A in the second embodiment described later can also be set to the same specification.

[0100] [Second Method] In addition, such as Figure 2 As shown, the intermediate layer A in the adhesive tape 20 can be a laminate consisting of adhesive layer a1, heating element b, and melt-softening layer c stacked sequentially. Alternatively, the intermediate layer A can also be a laminate consisting of: adhesive layer a1, heating element b, and adhesive layer a2 stacked sequentially; adhesive layer a1, heating element b, melt-softening layer c, and adhesive layer a2 stacked sequentially; adhesive layer a1, melt-softening layer c, heating element b, and adhesive layer a2 stacked sequentially; or adhesive layer a1, melt-softening layer c1, heating element b, melt-softening layer c2, and adhesive layer a2 stacked sequentially.

[0101] That is, the intermediate layer A of the second embodiment has a heating element, one or more adhesive layers a, and a melt-softening layer c. As an example of the intermediate layer A of the second embodiment, a laminate having a heating element b, an adhesive layer a disposed on one side of the heating element b, and a melt-softening layer c disposed on the other side of the heating element b can be given. Furthermore, as another example of the intermediate layer A of the second embodiment, a laminate having a heating element b, an adhesive layer a1 disposed on one side of the heating element b, an adhesive layer a2 disposed on the other side of the heating element b, and a melt-softening layer c disposed at at least one position between the heating element b and the adhesive layer a1, and between the heating element b and the adhesive layer a2.

[0102] At least the melt-softened layer c in the aforementioned intermediate layer A is melted or softened by heating, thereby allowing the intermediate layer A to be peeled off. In this case, each layer of adhesive layer a1 and adhesive layer a2 may contain an adhesive that is melted or softened by heating, or may not contain an adhesive that is melted or softened by heating. Furthermore, adhesive layer a1 and adhesive layer a2 may have the same composition or different compositions. Preferably, in the top view, the planar heating element b has a pair of protrusions extending from the outer periphery of adhesive layer a1, adhesive layer a2, and the melt-softened layer c. The details of the protrusions are the same as those of the protrusions in the planar heating element b in the intermediate layer A of the first embodiment described above.

[0103] <<Adhesive layer a>> In the intermediate layer A of the second method, the adhesive layer a is preferably formed of a pressure-sensitive adhesive or a hot-melt adhesive. Details regarding the adhesive used to form the adhesive layer a are the same as those described in the aforementioned section on "<<Adhesives>>".

[0104] In the intermediate layer A of the second method, the aforementioned melt-softening layer is a layer that is melted or softened by heating. Therefore, the aforementioned adhesive layer a can be melted or softened by heating, or it can remain unmelted or unsoftened, but it is preferred to be melted or softened.

[0105] In the intermediate layer A of the second embodiment, it is preferable that at least one of the adhesive layers a1 and a2 is a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive, and more preferably that both adhesive layers a1 and a2 are pressure-sensitive adhesive layers. The pressure-sensitive adhesive layer is viscous at room temperature, therefore, adhesive layer a1 and / or adhesive layer a2, as pressure-sensitive adhesive layers, can easily bond to other layers constituting the adhesive tape, such as the insulation layer, at room temperature.

[0106] Furthermore, at least one of the aforementioned adhesive layers a1 and a2 may be a hot-melt adhesive layer formed by a hot-melt adhesive, and both adhesive layers a1 and a2 may also be hot-melt adhesive layers. Hot-melt adhesives exhibit adhesive properties upon heating; therefore, adhesive layers a1 and / or a2, as hot-melt adhesive layers, can easily adhere and firmly bond to other layers constituting the adhesive tape, such as the insulation layer, upon heating.

[0107] 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.

[0108] <<Melted Softened Layer>> The aforementioned melt-softened layer is a layer that is melted or softened by heating. As for the aforementioned melt-softening layer, there are no particular limitations as long as it can achieve a tight fit with the aforementioned adhesive layer and the aforementioned heating element, and ensure the desired bonding strength between the adhered objects in the article described later. The resin layer that melts or softens with heat can be appropriately selected according to the purpose. Examples include: thermoplastic resin film, resin layer in which particles with a softening point lower than the aforementioned matrix resin are dispersed in the matrix resin, and resin layer in which particles with a softening point are dispersed in a matrix resin that does not have a softening point, etc. Examples of thermoplastic resins used in the aforementioned thermoplastic resin films 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. Additionally, thermoplastic resins and thermoplastic elastomers described in the above adhesives can also be used.

[0109] In cases where it is difficult to adjust the melting or softening temperature of the resin monomers constituting the thermoplastic film, the aforementioned thermoplastic film may contain additives such as plasticizers and tackifying resins.

[0110] The melting point of the aforementioned melt-softening layer is preferably 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. This is because, by keeping the melting point of the aforementioned melt-softening layer within the above range, it can be easily melted or softened even with a small amount of resistance heating. The melting point of the aforementioned melt-softening layer can be adjusted by selecting the type and composition of the resin (especially a thermoplastic resin) that is the main component of the aforementioned melt-softening layer. The melting point (melting temperature) of the aforementioned melt-softening layer can be set to the temperature of the endothermic peak accompanying melting, as measured using differential scanning calorimetry (DSC).

[0111] Storage modulus G, as a melt softening layer, was determined by dynamic viscoelastic spectroscopy at 1 Hz and 23 °C. 23 From the viewpoint of ensuring good fixation with adjacent layers under normal conditions, 1.0 × 10⁻⁶ is preferred. 3 Pa ~ 1.0 × 10 9 Pa, more preferably 5.0 × 10 Pa. 3 Pa ~ 5.0 × 10 8 Pa, preferably 1.0 × 10 Pa. 4 Pa ~ 1.0 × 10 8 Pa. Storage modulus G of the above-mentioned molten softened layer. 23 The energy storage modulus G of the adhesive (adhesive layer) can be utilized 23The determination method is the same as that used for the previous determination.

[0112] The storage modulus of the aforementioned melt-softened layer is less than 1.0 × 10⁻⁶. 5 The preferred temperature for Pa is within the temperature range of 80℃ to 200℃, and the storage modulus of the aforementioned melt-softened layer is less than 1.0 × 10⁻⁶. 4 The temperature of Pa is more preferably in the temperature range of 80°C to 200°C, and the storage modulus of the aforementioned melt-softened layer is less than 1.0 × 10⁻⁶. 3 The temperature of Pa is further preferably in the temperature range of 80°C to 200°C. The storage modulus of the aforementioned melt-softening layer is less than 1.0 × 10⁻⁶. 5 The temperature of Pa exists in the temperature range of 80°C to 200°C. It is advantageous that when the molten softened layer reaches this temperature through heating from the heating element, it melts or softens and peels off within the molten softened layer or at the interface of layers adjacent to these layers. The storage modulus of the aforementioned molten softened layer can be measured in the same way as the storage modulus of the aforementioned adhesive layer.

[0113] When the above-mentioned melt-softening layer is present, there is no particular limitation on the average thickness of the melt-softening layer, which can be appropriately selected according to the purpose. It is preferably 5 μm to 200 μm, more preferably 10 μm to 150 μm, and even more preferably 20 μm to 100 μm.

[0114] [Third Method] When the intermediate layer A is a single layer, it can also be a single layer in the adhesive tape 30 that includes the heating element b and the adhesive layer a3 containing the adhesive (see [reference]). Figure 3 The heating element b can be mesh-like or dispersed with particles or fibers containing the heating element, and can be appropriately selected according to the heating method used. The adhesive layer a3 preferably contains at least one of the pressure-sensitive adhesive containing the above-mentioned thermoplastic resin and the above-mentioned hot melt adhesive as the adhesive. The adhesive layer a3 melts or softens by heating, thereby reducing the adhesive strength, and the intermediate layer A can be peeled off.

[0115] In the third-party intermediate layer A, the adhesive layer a3 is preferably formed of a pressure-sensitive adhesive or a hot-melt adhesive. Details regarding the adhesive used to form the adhesive layer a3 can be found in the same section described above under "<<Adhesive>>". Furthermore, in the third-party intermediate layer A, details regarding the heating element b included in the adhesive layer a3 can be found in the same section described above under "<<Heating Element>>".

[0116] In the third-party intermediate layer A, it is preferable that both sides of the intermediate layer (the outermost surfaces located at opposite positions in the thickness direction of the intermediate layer) have adhesive properties (pressure-sensitive adhesive and / or thermal adhesive).

[0117] In the intermediate layer A of the third type, the adhesive forming the adhesive layer a3 can be a pressure-sensitive adhesive. That is, adhesive layer A can be a pressure-sensitive adhesive layer a3 containing a heating element. This is because both sides of adhesive layer A can be tacky at room temperature, allowing it to adhere to and bond with other layers constituting the adhesive tape of the present invention, such as the insulation layer.

[0118] Furthermore, in the third-party adhesive layer A, the adhesive forming adhesive layer a3 can be a hot-melt adhesive. That is, the intermediate layer A can be a hot-melt adhesive layer a3 containing a heating element. Hot-melt adhesives exhibit adhesive properties when heated, therefore, adhesive layer A, as a hot-melt adhesive layer, can be easily bonded to other layers constituting the adhesive tape, such as the insulation layer, when heated.

[0119] The total thickness of the intermediate layer A, when the intermediate layer A is a single layer, is not particularly limited and can be appropriately selected according to the purpose. It is preferably 15μm to 500μm, more preferably 30μm to 400μm, and even more preferably 50μm to 300μm.

[0120] <Adhesive layers B1 and B2> The adhesive layer B1 comprises at least adhesive B1, and may further comprise other components as needed. Adhesive layer B1 is disposed on one side of the intermediate layer A. Adhesive layer B2 comprises at least adhesive B2, and may further comprise other components as needed. Adhesive layer B2 is disposed on the other side of the intermediate layer A. At least either adhesive layer B1 or adhesive layer B2 may be an insulating layer C that also provides thermal insulation. There are no particular limitations on adhesives B1 and B2; known or commonly used adhesives can be appropriately selected depending on the purpose, such as pressure-sensitive adhesives. As the pressure-sensitive adhesive, the pressure-sensitive adhesive described in the intermediate layer A can be appropriately selected. Adhesives B1 and B2 may have the same composition or different compositions.

[0121] As other components mentioned above, the other components described in the intermediate layer A can be appropriately selected.

[0122] The average thickness of the adhesive layer B1 and the adhesive layer B2 is not particularly limited and can be appropriately selected according to the purpose. It is preferably 5μm to 200μm, more preferably 10μm to 150μm, and even more preferably 15μm to 100μm.

[0123] <Insulation Layer C> As for the aforementioned insulation layer C, there are no particular restrictions as long as it has thermal insulation properties, and it can be appropriately selected according to the purpose. For example, a planar layer with voids (hollows) within a foam layer, a hollow layer, or a hollow particle layer can be cited. Among these, a foam layer is preferred from the viewpoints of flexibility and adhesive conformability.

[0124] The thermal conductivity of the aforementioned insulation layer C, as measured according to ASTM-D5470, is preferably 0.15 W / m·K or less, more preferably 0.1 W / m·K or less, more preferably 0.08 W / m·K or less, and even more preferably 0.06 W / m·K or less. By ensuring that the thermal conductivity of the insulation layer C is within the aforementioned range, heat conduction from the heating element to the adhered material can be shielded, allowing the heat generated in the heating element to be efficiently used for melting or softening the intermediate layer A.

[0125] When the aforementioned insulation layer C is a foamed layer, the foamed layer can consist of individual air bubbles or continuous air bubbles. As the foamed layer, polyolefin foams containing polyethylene, polypropylene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, etc., polyurethane foams, and rubber foams containing acrylic rubbers, other elastomers, etc., can be used. Among these, polyolefin foams are preferred from the perspective of excellent shape retention at high temperatures.

[0126] When at least one of the adhesive layers B1 and B2 is also a heat-insulating layer C, examples of heat-insulating layer C include a hollow adhesive layer and an adhesive layer containing hollow particles. Alternatively, the heat-insulating layer C may be disposed at at least one of the intermediate layer A and the adhesive layer B1, and at least one of the intermediate layer A and the adhesive layer B2. Preferably, the heat-insulating layer C is disposed at either the intermediate layer A and the adhesive layer B1, or the intermediate layer A and the adhesive layer B2.

[0127] Alternatively, the insulation layer C is preferably characterized by having a first region and a second region with a thermal conductivity lower than that of the first region. The first region is not particularly limited and can be appropriately selected depending on the purpose; for example, the adhesive and resin described above can be used. Examples of resins include polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; acrylic resins; styrene resins such as polystyrene; urethane resins such as polyurethane; polyvinyl chloride resins; olefin elastomers; acrylic elastomers; styrene elastomers; butyl elastomers; and rubber resins such as natural rubber. The second region is not particularly limited and can be appropriately selected depending on the purpose; it can be air, an inert gas, hollow particles containing the gas, a liquid or solid with low thermal conductivity, or a filler containing the liquid or solid. Among these, a gas or hollow particles containing the gas are preferred.

[0128] The average thickness of the aforementioned insulation layer C is not particularly limited as long as it achieves the desired insulation performance, and can be appropriately selected according to the purpose. Preferably, it is 15 μm to 1000 μm, more preferably 30 μm to 500 μm, and even more preferably 50 μm to 200 μm. Furthermore, the porosity of the aforementioned insulation layer C is only required to achieve porosity-based insulation performance, preferably 5% to 90%, more preferably 10% to 80%, and even more preferably 20% to 70%. Having the thickness and porosity of the insulation layer C within the aforementioned ranges is advantageous in terms of efficiently achieving the insulation effect of the insulation layer C.

[0129] The porosity of the aforementioned insulation layer C represents the proportion of gas-containing voids and porous pores (voids) contained in the insulation layer C relative to the insulation layer C itself, and can be calculated using the following method. First, according to JIS K 6767, the insulation layer with a pre-determined thickness is cut into rectangles of 4cm × 5cm, and approximately 15cm... 3 The quantity is measured, its mass is determined, and the density (X1) is calculated from the mass and volume. Next, the density (X2) is calculated from the density of the materials originating from the region outside the voids constituting the insulation layer and their proportions. If the insulation layer is composed of one component, the density of the material originating from that component is density (X2). For example, if the insulation layer is formed only of acrylic resin, the density of the acrylic resin is density (X2). Furthermore, if the insulation layer is composed of n components, the density (X2) can be calculated using the following formula. Density (X2) = (Density of material derived from component 1 × Proportion of component 1 in the insulation layer material) + (Density of material derived from component 2 × Proportion of component 2 in the insulation layer material) + ... + (Density of material derived from component n × Proportion of component n in the insulation layer material) It should be noted that the total proportion of components 1 to n is 100 by mass. The porosity is calculated based on the obtained densities (X1) and (X2) using the following formula. Porosity (%) = {1 - (density x1 / density x2)} × 100

[0130] <Peeling Layer> The adhesive tape described above may have other layers such as a release layer. There are no particular limitations on the release layer; it can be appropriately selected depending on the purpose. Examples include: cellophane, kraft paper, clay-coated paper, paper laminated with polyethylene films, paper coated with resins such as polyvinyl alcohol or acrylate copolymers, and release layers coated with fluoropolymers, silicone resins, etc., as release agents, onto synthetic resin films such as polyester or polypropylene. The release layer may be present on one side or both sides of the adhesive tape.

[0131] [Uses of adhesive tape] The adhesive tape of the present invention does not include the two sides of the release liner that function as adhesive surfaces, thus allowing the adhered objects to be bonded to both sides of the adhesive tape, making it suitable for bonding the adhered objects together. The adhesive tape of the present invention can be peeled off by resistance heating, therefore it can be used as a resistance heating (electric heating) release tape.

[0132] The adhesive tape of the present invention is not particularly limited and is suitable for bonding and separating objects that are rigid. When separating parts during reuse or recycling, the adhesive tape of the present invention can be easily removed by heating. Therefore, it can be used in applications where adhesive tape peeling is required. For example, it is suitable for use as an adhesive tape for fixing parts of various products in industrial applications such as electronics, automobiles, building materials, office automation, and home appliances. It also offers good work efficiency when separating large numbers of parts or peeling off large numbers of labels during reuse or recycling.

[0133] [Layer Composition of Adhesive Tape] The layer composition of the adhesive tape described above will be explained using the accompanying drawings. For example... Figure 1A and Figure 1B As shown, the adhesive tape 10 has an intermediate layer A, an adhesive layer B1 disposed on one side of the intermediate layer A, and an adhesive layer B2 disposed on the other side of the intermediate layer A; heat insulation layers C are respectively located between the intermediate layer A and the adhesive layer B1, and between the intermediate layer A and the adhesive layer B2; it can be a laminate consisting of adhesive layer B1 / heat insulation layer C1 / intermediate layer A / heat insulation layer C2 / adhesive layer B2 stacked sequentially. It should be noted that... Figure 2 and 3The adhesive tapes 20 and 30 shown also illustrate a laminated structure, similar to Figure 1, consisting of adhesive layer B1 / insulation layer C1 / intermediate layer A / insulation layer C2 / adhesive layer B2, except for a different layer composition in the intermediate layer A. Adhesive layer B1 and adhesive layer B2 can have the same composition or different compositions. Similarly, insulation layer C1 and insulation layer C2 can have the same composition or different compositions.

[0134] like Figure 4 As shown, the adhesive tape 40 has an intermediate layer A, an adhesive layer B1 disposed on one side of the intermediate layer A, and an adhesive layer B2 disposed on the other side of the intermediate layer A. An insulating layer C is provided at any position between the intermediate layer A and the adhesive layer B1, and between the intermediate layer A and the adhesive layer B2. It can be a laminate consisting of adhesive layer B1, insulating layer C1, intermediate layer A, and adhesive layer B2 stacked sequentially. Alternatively, it can be a laminate consisting of adhesive layer B1, intermediate layer A, insulating layer C2, and adhesive layer B2 stacked sequentially. As the intermediate layer A, any of the methods described in steps 1 to 3 above can be appropriately selected.

[0135] like Figure 5 As shown, the adhesive tape 50 has an intermediate layer A, an adhesive layer B1 disposed on one side of the intermediate layer A, and an adhesive layer B2 disposed on the other side of the intermediate layer A. At least one of the adhesive layer B1 and the adhesive layer B2 can be an insulating layer C that also has heat insulation properties. The adhesive tape 50 is a laminate in which adhesive layer B1 (= insulating layer C1) / intermediate layer A / adhesive layer B2 (= insulating layer C2) are stacked in sequence. Alternatively, the adhesive tape can be a laminate in which adhesive layer B1 (= insulating layer C1) / intermediate layer A / adhesive layer B2 are stacked in sequence, or it can be a laminate in which adhesive layer B1 / intermediate layer A / adhesive layer B2 (= insulating layer C2) are stacked in sequence. As the intermediate layer A, any of the first to third methods described above can be appropriately selected.

[0136] [Manufacturing method of adhesive tape] As a method for manufacturing the aforementioned adhesive tape, examples include: preparing an adhesive layer obtained by coating a release sheet with a composition comprising the aforementioned adhesive B1 and drying it; preparing an adhesive layer obtained by coating a release sheet with a composition comprising the aforementioned adhesive B2 and drying it; and an insulating layer C, and sequentially bonding them to each side of the aforementioned intermediate layer A. As a method for manufacturing the aforementioned intermediate layer A, if the intermediate layer A has a planar heating element or an integrally formed mesh-like heating element, examples include: coating a release sheet with a composition comprising the aforementioned adhesive a1; furthermore, coating a release sheet with a composition comprising the aforementioned adhesive a2; and after a drying process, sequentially bonding it to each side of the aforementioned heating element. If the aforementioned intermediate layer A has a granular or fibrous heating element, examples include: coating a release sheet with a composition comprising a granular or fibrous heating element and an adhesive; after a drying process, bonding the release sheet (or adhesive layers B1, B2, insulating layer C, etc.) to it.

[0137] As a method for manufacturing the aforementioned insulation layer C, known methods can be used depending on the type of insulation layer. For example, when the insulation layer C is a foamed layer, a known foam manufacturing method can be used to manufacture the foamed layer. Specifically, a mixture obtained by adding a foaming agent and a crosslinking agent to a foaming resin, and adding additives such as multifunctional monomers and fillers as needed, is molded into a specific shape, crosslinked by irradiation or heating at a temperature below the decomposition temperature of the foaming agent, and then heated to above the decomposition temperature of the foaming agent to foam. It should be noted that the above crosslinking and foaming can also be performed simultaneously. In addition, commercially available foams can also be used as the insulation layer. When the insulation layer C is a hollow layer, for example, a composition in which thermally expanding fillers are dispersed in a resin can be used, formed into a layer by a desired method such as extrusion or coating, and a hollow layer is manufactured by foaming the thermally expanding fillers to form hollows within the layer. When the insulation layer C is a hollow particle layer, the hollow particle layer can be manufactured by forming the composition in which hollow particles are dispersed in the resin into a layer by means of desired methods such as extrusion or coating.

[0138] 2. Items The article of the present invention comprises at least two adherends and an adhesive strip of the present invention located between the two adherends, the two adherends being bonded together via the adhesive strip. As a method of bonding the adherends, examples include attaching the adherends to the adhesive surfaces of the adhesive strip respectively, thereby bringing the two adherends together. There are no particular limitations on the article; it can be appropriately selected depending on the purpose, and is preferably an electronic device, a component built into an electronic device, etc. Preferably, in a top view, the adhesive strip has a pair of protrusions extending from the outer periphery of the adherends.

[0139] Adhesive tape Details regarding the adhesive tape in the articles of the present invention are as described in the item “1. Adhesive Tape” above.

[0140] <Object to be adhered> The aforementioned adhesive material can be rigid or flexible, such as a membrane. There are no particular limitations on the adhesive material; it can be appropriately selected depending on the purpose. Examples include metal plates, metal frames, metal covers, glass plates, and plastic plates; and components of any of these types can be present on the adhesive surface. The two adhesive materials bonded by the adhesive tape can be the same or different from each other.

[0141] For example, such as Figure 6A schematic plan and Figure 6B As shown in the schematic cross-sectional view, the article 100 of the present invention includes an adhesive tape 10, which comprises two adherends 90 and a laminate consisting of an adhesive layer B1, an insulation layer C1, an intermediate layer A, an insulation layer C2, and an adhesive layer B2 sequentially stacked between the two adherends 90, wherein the two adherends 90 are bonded to each other via the adhesive tape 10. In the top view (… Figure 6A In the adhesive layer A, both ends of the intermediate layer A extend from the outer periphery of the adhered material along its long axis. Furthermore, both ends of the planar heating element b extend from the outer periphery of adhesive layers a1 and a2 along their long axes. In the disassembly method of the article described later, the two ends of the protruding adhesive tape 10 can be used as a pair of terminals for electrical connection to a power source or as ends in contact with a heat source, in cases where the heating means are either resistance heating or heat conduction, and the heating element b of the adhesive tape 10 can be easily heated. Additionally, as... Figure 6A As shown in the top view, when the contact area between the object being adhered and the adhesive tape is small, the heating efficiency of the heating element is high, and it is easy to create an opportunity for disassembly during heating, thus it is advantageous in terms of ease of disassembly.

[0142] Additionally, although not illustrated, the article of the present invention may also be an article comprising two adherends 90 and any one of the adhesive strips 10 to 50 shown in Figures 1 to 5 between the two adherends 90, and the two adherends 90 are bonded together by the adhesive strip.

[0143] In the top view of the aforementioned item, the adhesive tape can be applied to the entire area of ​​the adhesive tape side (i.e., the surface to be bonded), or it can be applied to a portion of the adhesive tape surface. For example, Figure 6A As illustrated, it is preferable that the adhesive tape 10 is adhered to a portion of the adhesive surface of the adherend 50. By making the contact area between the adherend and the adhesive tape small, a peeling start point becomes easier to generate between the adherend and the adhesive tape when the adhesive tape is peeled off from the adherend by resistance heating, which is advantageous in terms of ease of peeling.

[0144] like Figure 6A As illustrated, in the top view of the article of the present invention, when the adhesive tape 10 is attached to a portion of the adhesive surface of the adhesive 50, the top view shape of the adhesive tape 10 in the article can be strip-shaped, line-shaped, or patterned.

[0145] Furthermore, in the top view of the article of the present invention, when the adhesive tape is adhered to the entire area of ​​the adhesive tape side of the object to be adhered, that is, the adhesive tape surface, the top view shape of the planar heating element in the adhesive tape can be the same as the top view shape of the adhesive tape, or it can be strip-shaped, line-shaped, or patterned.

[0146] 3. Methods for disassembling items The method for disassembling the article of the present invention is a method for disassembling the article of the present invention, or a method for disassembling an article formed by two adhered objects bonded together by the adhesive tape of the present invention, which includes a separation step and may further include other steps as needed.

[0147] The details regarding the article used in the disassembly method of the present invention and the adhesive tape used in the article are the same as those described in the items “2. Article” and “1. Adhesive Tape” above.

[0148] <Separation Process> The above separation process is a process of separating the two adhered objects by heating the above-mentioned heating element to soften or melt the above-mentioned intermediate layer A.

[0149] There are no particular limitations on the means and methods of heating the aforementioned heating element, and they can be appropriately selected according to the purpose. For example, electromagnetic induction heating, infrared heating, microwave heating, heat conduction, and resistance heating can be cited. Among these, resistance heating is preferred.

[0150] <<Resistance Heating>> When the heating of the heating element is resistance heating, the separation process is preferably the following: the intermediate layer A is electrically connected to a power source, the heating element is powered by the power source, and the intermediate layer A is softened or melted by resistance heating to separate the two adhered objects.

[0151] There are no particular limitations on the power source, and it can be appropriately selected according to the purpose. It can be an external power source or a driving power source for an electronic device or the aforementioned article that is a component built into an electronic device, but it is preferred to be a driving power source for an electronic device or a component built into an electronic device. In addition, when the aforementioned article is an electronic device or a component built into an electronic device, and the aforementioned power source is a driving power source for the aforementioned electronic device, the aforementioned separation process is preferably the following process: electrically connecting the aforementioned intermediate layer A to the aforementioned driving power source and circuit of the aforementioned electronic device, passing electricity from the aforementioned driving power source to the aforementioned heating element, and separating the two aforementioned adhered objects by melting or softening the aforementioned intermediate layer A through resistance heating.

[0152] As a method for electrical connection, known means such as alligator clips can be used to electrically connect the intermediate layer A (preferably the heating element, or the two ends of the protruding heating element) to the power source. The circuit and the means of electrical connection are preferably formed of a conductive material exhibiting a volume resistivity different from that of the heating element in the adhesive tape, and more preferably of a conductive material with a volume resistivity lower than that of the heating element. By forming the circuit with a conductive material having a volume resistivity lower than that of the heating element, it is advantageous to prevent overheating of the circuit and the means of electrical connection when the heating element is electrically connected to the circuit and energized from the driving power source, and to efficiently apply voltage to the intermediate layer A so that it can be peeled off in a short time.

[0153] As for the above-mentioned method of applying electricity, it can be appropriately selected according to the size of the adhesive tape, the heating element used, etc. For example, a method of applying a voltage of 0.1V to 200V until the adhesive layer A melts or softens (e.g., 0.5 seconds to 30 minutes) can be cited. For example, such as Figure 7 As schematically illustrated, a simple power source can be used to electrically connect the intermediate layer A of the adhesive tape to the power source, apply voltage to the heating element to energize it, and thereby heat the heating element and its surroundings through resistance heating. As a result, the adhesive or any melt-softening layer softens or melts, releasing the adhesive state at a desired location within or on the intermediate layer A itself, thus allowing the intermediate layer A to be peeled off and the adhered objects to be removed.

[0154] The voltage applied to the heating element by energizing it is not particularly limited, but is preferably 0.1V or higher and 200V or lower, more preferably 0.5V or higher and 150V or lower, and even more preferably 1.0V or higher and 100V or lower. Even with a low applied voltage, the adhesive layer A of the adhesive tape of the present invention softens or melts within a short time. Therefore, by setting the voltage applied in the separation process within the above-mentioned range, the article can be disassembled in a short time without applying excessive voltage, thus preventing damage to the article. In particular, by applying a voltage compatible with small electronic devices and household appliances, the disassembly of these articles can be easily performed.

[0155] The current flowing through the heating element is not particularly limited, but is preferably 0.01A or more and 20A or less, preferably 0.03A or more and 15A or less, preferably 0.05A or more and 10A or less, and more preferably 0.1A or more and 5A or less. Because the adhesive tape of the present invention softens or melts the adhesive layer A in a short time, by setting the current applied in the separation process within the above-mentioned range, the current flowing through common electronic devices and household appliances can be used to disassemble the items in a short time, preventing damage to the items. In particular, by applying a current that is compatible with small electronic devices and household appliances, the disassembly of these items can be easily performed.

[0156] The application time of the current is not particularly limited, but is preferably 0.5 seconds or more and 30 minutes or less, more preferably 0.5 seconds or more and 120 seconds or less, and even more preferably 0.5 seconds or more and 30 seconds or less. By setting the application time to the above range and applying an appropriate voltage, disassembly can be performed in a short time without damaging the item.

[0157] <<Electromagnetic Induction Heating>> When the heating element described above is heated by electromagnetic induction heating, the preferred separation step is to soften or melt the intermediate layer A by using electromagnetic induction heating to separate the two adhered materials. There are no particular limitations on the electromagnetic induction heating method; any known electromagnetic induction heating device can be appropriately selected depending on the purpose.

[0158] <<Infrared Heating and Microwave Heating>> When the heating element described above is either infrared heating or microwave heating, the separation process is preferably a process in which the intermediate layer A is softened or melted by either infrared heating or microwave heating to separate the two adhered materials. There are no particular limitations on the infrared heating method or microwave heating method; known infrared heating devices and microwave heating devices can be appropriately selected according to the purpose.

[0159] Heat conduction When the heating of the aforementioned heating element is achieved through heat conduction, the preferred separation step is to bring the intermediate layer A into contact with the heating source, thereby softening or melting the adhesive layer A through heat conduction to separate the two adhered materials. There are no particular limitations on the heating source; any known heater can be appropriately selected depending on the purpose. The heat conduction method using the heating source can be appropriately selected based on the size of the adhesive tape, the heating element used, etc.; for example, a method that brings the layers into contact at a desired temperature until the intermediate layer A melts or softens can be cited. Example

[0160] The present invention will now be described in more detail with reference to the embodiments, but the present invention is not limited to the following embodiments. It should be noted that, unless otherwise specified, "parts" refers to "parts by mass" and "%" refers to "% by mass". In addition, the adhesive tape shown in the embodiments and reference examples is configured without a release liner, and the total thickness of the adhesive tape does not include the thickness of the release liner.

[0161] <Methods for Determining Physical Properties> (energy storage modulus G) 23 and energy storage modulus G 100 ) The storage modulus G of the adhesive layer a formed by the adhesive compositions (P-1) and (P-2) 23 and energy storage modulus G 100 The following method was used for determination. Using a viscoelasticity testing machine (ARES-G2, manufactured by TA Instruments Japan), a test piece was sandwiched between parallel discs with a diameter of 8 mm, which served as the measuring section of the machine. The storage modulus G′ was measured at a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a heating rate of 2°C / min. The values ​​at 23°C and 100°C were recorded. For the test piece, an adhesive composition was applied using an applicator to a dry thickness of approximately 2 mm and dried. An adhesive layer (adhesive layer) was then used, cured at 40°C for 48 hours.

[0162] (Measured value of volume resistivity of the heating element) The measured volume resistivity of the heating element used in the examples and reference examples was determined using a low resistivity meter (manufactured by Nitto Seiko Analytech Co., Ltd., trade name: "Loresta-AX MCT-T370") and a four-probe probe (manufactured by Nitto Seiko Analytech Co., Ltd., trade name: "ASP probe MCP-TP03P"), according to JIS K 7194 at room temperature (20°C). The number of measurement points was set to one, and a resistivity correction factor of 4.532 was used.

[0163] <Preparation of Adhesive Composition (P-1)> 100 parts by weight of styrene-isoprene block copolymer composition a (a mixture of styrene-isoprene diblock copolymer and styrene-isoprene triblock copolymer, wherein 24% by mass of styrene-derived structural units represented by the following chemical formula (1), and the proportion of styrene-isoprene diblock copolymer to the total amount of composition a is 67% by mass), 40 parts by mass of Quintone G115 (a C5 / C9 series petroleum resin manufactured by Zeon Corporation of Japan, with a softening point of 115°C), and Pensel 30 parts by weight of D-160 (polymerized rosin ester resin manufactured by Arakawa Chemical Industry Co., Ltd., softening point 15℃~150℃), 5 parts by weight of Nippon Seki polybutene HV-50 (polybutene manufactured by JX Nippon Seki Energy Co., Ltd., flow point -12.5℃), and 1 part by weight of anti-aging agent (tetra-[methylene-3-(3′5′-di-tert-butyl-4-hydroxyphenyl)propionate]methane) are dissolved in 100 parts by weight of toluene as solvent to obtain the adhesive composition (P-1).

[0164] [Chemical Formula 1]

[0165] <Preparation of Adhesive Composition (P-2)> 79.9 parts by mass of n-butyl acrylate, 6 parts by mass of 2-ethylhexyl acrylate, 10 parts by mass of cyclohexyl acrylate, 4 parts by mass of acrylic acid, 0.1 parts by mass of 4-hydroxybutyl acrylate, and 200 parts by mass of ethyl acetate were added to a reaction vessel equipped with a stirrer, reflux condenser, nitrogen inlet tube, and thermometer. The mixture was stirred and bubbled under nitrogen at room temperature for 1 hour to obtain a mixture. Next, 2 parts by mass of a 2,2′-azobis(2-methylbutyronitrile) solution (1.0% by mass of solids) pre-dissolved in ethyl acetate was added to the above mixture. The mixture was stirred and maintained at 72°C for 4 hours, followed by a further maintenance at 75°C for 5 hours. The resulting mixture was then diluted with ethyl acetate and filtered through a 200-mesh metal mesh to obtain an acrylic copolymer (A-1) solution (26% solids concentration) with a weight average molecular weight of 1,060,000 and an average carbon number of 4.4 saturated hydrocarbon groups in the alkyl acrylate monomers. In 100 parts by mass of the above acrylic copolymer (A-1) solution, 1.0 parts by mass of the adduct of toluene diisocyanate and trimethylolpropane ("BURNOCKD-40" manufactured by DIC Corporation, an isocyanate-based crosslinking agent, 40% solid content, hereinafter "D-40") was added to obtain the adhesive composition (P-2).

[0166] (Example 1) Making Adhesive Tape <<Production of Foam Layer>> As the heat insulating layer C, a polyethylene foam layer (thickness: 100 μm, porosity: 60%) is used.

[0167] <<Production of Intermediate Layer A>> The adhesive composition (P-1) is applied to the release-treated surface of a release liner (a 75 μm-thick polyethylene terephthalate film with release treatment performed on one side) such that the thickness after drying becomes 50 μm, and dried at 90°C for 3 minutes to produce an adhesive layer a1.

[0168] Next, the adhesive composition (P-2) is applied to the release-treated surface of a release liner (a 75 μm-thick polyethylene terephthalate film with release treatment performed on one side) such that the thickness after drying becomes 50 μm, and dried at 90°C for 3 minutes to produce an adhesive layer a2.

[0169] As the heating element, a 10 μm-thick nichrome foil (manufactured by Takeuchi Metal Foil & Powder Industry Co., Ltd., "Nichrome NCH1-H") is used. The adhesive layer a1 cut to a length of 50 mm and any width and the nichrome foil cut to a length of 100 mm are bonded together using a hand pressure roller, and positioned such that both ends of the nichrome foil each protrude 25 mm in the length direction. Similarly, the adhesive layer a2 cut to a length of 50 mm and any width is bonded to the opposite surface of the nichrome foil that is bonded to the adhesive layer a1, and laminated with a roller having a linear pressure of 5 kg / cm from the upper surface of the above-mentioned release liner. After forming a laminated body with a total thickness of 110 μm in a shape where both ends of the nichrome foil each protrude 25 mm in the length direction of the nichrome foil from the outer peripheries of the adhesive layer a1 and the adhesive layer a2, the laminated body is aged for 48 hours in an environment of 40°C. The resulting product is cut to a width of 2 mm, whereby the intermediate layer A is obtained, in which the adhesive layer a1 and the adhesive layer a2 have a dimension of 2 mm in width × 50 mm in length, the nichrome foil has a dimension of 2 mm × 100 mm in length, and the nichrome foil has a pair of protruding portions protruding from the outer peripheries of the adhesive layer a1 and the above-mentioned adhesive layer a2. It should be noted that, for the volume resistivity of the nichrome foil, the catalog value is 108 μΩ·cm, and the actually measured value is 105 μΩ·cm. The intermediate layer A obtained in Example 1 is designated as intermediate layer (A-1).

[0170] Regarding the viscoelastic parameters of the adhesive layer formed from the adhesive composition (P-1), the storage modulus G at 23°C 23 is 3.E+05, the loss tangent (tanδ) at 23°C is 0.33; the storage modulus G at 100°C 1008.E+04, loss tangent (tanδ) at 100℃: 0.48; temperature at which loss tangent (tanδ) reaches 0.45 or above: above 94℃. Regarding the viscoelastic parameters of the adhesive layer formed by the adhesive composition (P-2), the storage modulus G at 23°C 23 Loss tangent (tanδ) at 23℃: 0.69; Energy storage modulus G at 100℃ 100 2.E+04, loss tangent (tanδ) at 100℃: 0.33; temperature at which loss tangent (tanδ) reaches 0.45 or higher: above 150℃.

[0171] <<Fabrication of the laminate of adhesive layer B1 and insulation layer C>> The adhesive composition (P-2) was coated to a thickness of 50 μm after drying onto the release liner (a 75 μm thick polyethylene terephthalate film with a single-sided release treatment). The mixture was dried at 90°C for 3 minutes to obtain adhesive layer B1. After bonding adhesive layer B1 with the insulation layer C (polyethylene foam layer), lamination was performed from the upper surface of the release liner using a roller with a linear pressure of 5 kg / cm. The lamination was cured at 40°C for 48 hours to obtain a laminate (T-2) containing adhesive layer B1 and insulation layer C with a total thickness of 150 μm. Two laminates (T-2) were produced.

[0172] With the foam layer and the intermediate layer (A-1) in contact on both sides, two laminates (T-2) cut to arbitrary widths with a length of 50 mm are sandwiched in, and the ends of adhesive layers a1 and a2 are aligned with the ends of T-2. The laminate is then applied from the upper surface of the release liner using a roller with a linear pressure of 5 kg / cm to obtain the adhesive tape of Example 1 with a total thickness of 410 μm.

[0173] Regarding the adhesive tape of Example 1, excluding the release liner, the layer configuration consists of adhesive layer B1 / insulation layer C / adhesive layer a1 / heating element b / adhesive layer a2 / insulation layer C / adhesive layer B1 stacked sequentially. Adhesive layers a1 and a2, as well as adhesive layer B1, are laminates containing pressure-sensitive adhesive. Furthermore, regarding the adhesive tape of Example 1, the dimensions of the adhesive surface (effective portion) are 2mm wide × 50mm long, and the dimensions of the nickel-chromium alloy foil are 2mm wide × 100mm long. The two ends of the nickel-chromium alloy foil extend from the outer periphery of adhesive layer a1 (and the adhesive layer a2 on the back side) (see reference). Figure 8A and Figure 8B Regarding the volume resistivity of the nickel-chromium alloy foil, the rated value is 108 μΩ·cm, and the measured value is 105 μΩ·cm.

[0174] <Item Crafting> Regarding the adhesive tape of Example 1 ( Figure 9A ~C, indicated by reference numeral 10 in the attached drawing, peel off the release liner near the adhesive layer a1, and attach it to the substrate 90a (glass, 40mm wide × 50mm long × 10mm thick) with a length of 50mm including the adhesive surface (effective portion) across the center of the substrate 90a along its length (refer to...). Figure 9A ~C). Next, peel off the release liner on the adhesive layer a2 side, and use it to sandwich the adhesive tape 10 into the shape of the object 90b (glass, 30mm wide × 100mm long × 2.8mm thick) (refer to). Figure 9A ~C) Paste, at 20N / cm 2 Press for 10 seconds, and place the resulting adhesive at 23°C and 50% RH for more than 24 hours to obtain the article of Example 1.

[0175] (Refer to Example 1) In Example 1, the laminate (T-2) was not bonded; only the intermediate layer (A-1) was made into the adhesive tape of Reference Example 1. Otherwise, through the same operation as in Example 1, the adhesive tape of Reference Example 1 with a total thickness of 110 μm was obtained as a laminate consisting of adhesive layer a1 / heating element b / adhesive layer a2 stacked sequentially, excluding the release liner. In addition, in Example 1, the adhesive tape of Reference Example 1 was used instead of the adhesive tape of Example 1. Otherwise, through the same operation as in Example 1, the article of Reference Example 1 was obtained, which consisted of an object to be bonded (glass, width 40 mm × length 50 mm × thickness 10 mm) / adhesive layer a1 / heating element b / adhesive layer a2 / object to be bonded (glass, width 30 mm × length 100 mm × thickness 2.8 mm).

[0176] (Example 2) Intermediate layer A was obtained by replacing the nickel-chromium alloy foil with a 10 μm thick stainless steel foil (manufactured by Takeuchi Metal Foil Powder Industry Co., Ltd., trade name: "Stainless Steel SUS304-H") with a volume resistivity of 72.0 μΩ·cm (nominal value 79.9 μΩ·cm). Otherwise, the adhesive tape and article of Example 2 with a total thickness of 410 μm were obtained by the same operation as in Example 1. Intermediate layer A in Example 2 was used as intermediate layer (A-2).

[0177] (Example 3) Intermediate layer A was obtained by replacing the nickel-chromium alloy foil with a 10 μm thick stainless steel foil (manufactured by Takeuchi Metal Foil Powder Industry Co., Ltd., trade name: "Stainless Steel SUS430-H") with a volume resistivity of 60.0 μΩ·cm (nominal value 62.0 μΩ·cm). Otherwise, the adhesive tape and article of Example 3 with a total thickness of 410 μm were obtained by the same operation as in Example 1. Intermediate layer A in Example 3 was used as intermediate layer (A-3).

[0178] (Example 4) Intermediate layer A was obtained by replacing the nickel-chromium alloy foil with a 10 μm thick titanium foil (manufactured by Takeuchi Metal Foil Powder Industry Co., Ltd., trade name: "A Titanium TR270C-H") with a volume resistivity of 55.0 μΩ·cm (nominal value 51.8 μΩ·cm). Otherwise, the adhesive tape and article of Example 4 with a total thickness of 410 μm were obtained by the same operation as in Example 1. Intermediate layer A in Example 4 was used as intermediate layer (A-4).

[0179] (Example 5) 7.5g of amphoteric surfactant (manufactured by Toho Chemical Industry Co., Ltd., trade name: "Obazoline CAB-30") and 7.6g of carbon nanotubes (manufactured by Nanocyl Corporation, trade name: "NC7000") were mixed in 500ml of water to make an aqueous solution. The solution was then placed in the ball mill body (capacity = 900ml, ball mill diameter = 130mm, ball filling amount = 1600g) and gently made into a paste. The ball mill body was then placed on a rotating stand and stirred for 2 hours. The total amount of the obtained dispersion liquid was removed from the ball mill body, and 250 ml of a 15% aqueous solution of the above-mentioned amphoteric surfactant was added. The mixture was then filled into a ball mill (manufactured by WAB, trade name: "DYNO-MILL ECM-AP2", internal volume = 1900 ml, filled with 1800 g of zirconia beads with a diameter of 0.6 mm). The mixture was stirred at a speed of 300 times / minute for 60 minutes to prepare an aqueous dispersion of carbon nanotubes containing the amphoteric surfactant (concentration of carbon nanotubes = 0.99 w%).

[0180] An aqueous dispersion of carbon nanotubes was coated onto one side of a 25 μm thick polyimide film (manufactured by Toray DuPont, trade name: "Kapton 100H") using a rod coater to achieve a dried film thickness of 3 μm. The coating was dried at 100°C for 10 minutes, forming a carbon nanotube layer on the single side of the polyimide film, thus obtaining a carbon nanotube coated film. The measured volume resistivity of the carbon nanotube layer was 19270 μΩ·cm.

[0181] Using the carbon nanotube coating film described above instead of the nickel-chromium alloy foil of Example 1, except that the same operation as in Example 1 was performed, the adhesive tape and article of Example 5 with a total thickness of 428 μm were obtained. It should be noted that the carbon nanotube coating film described above is applied by bonding the carbon nanotube layer adjacent to the adhesive layer a1. The intermediate layer A in Example 5 is used as the intermediate layer (A-5).

[0182] (Example 6) Metal nonwoven fabric (material: SUS316L, thickness: 25μm, density: 1.6g / cm³) was used. 3 The adhesive tape and article of Example 6, with a total thickness of 425 μm, were obtained by replacing the nickel-chromium alloy foil with a fiber diameter of 7 μm and a measured volume resistivity of 783 μΩ·cm. Otherwise, the same operation as in Example 1 was followed. The intermediate layer A in Example 6 was used as the intermediate layer (A-6).

[0183] (Example 7) Making Adhesive Tape A crystalline polyester resin coating (manufactured by Mitsubishi Chemical Corporation, trade name: "Nichigo-Polyester MSP-640", melting point 100℃, molecular weight 10000, non-sticky) (P-3) was applied to the release-treated side of the release liner (a 75μm thick polyethylene terephthalate film with a single-sided release treatment) to a thickness of 50μm after drying. The coating was then dried at 90℃ for 3 minutes to create a melt-softened layer c.

[0184] Perform the same procedure as in Example 1, preparing two adhesive layers, each 50 μm thick, formed by coating and drying an adhesive composition (P-2) onto a release liner. One layer is designated as adhesive layer a1, and the other as adhesive layer a2. Next, a molten softened layer c, cut to arbitrary widths with a length of 50 mm, and a 100 mm long nickel-chromium alloy foil are laminated using a hand roller, positioned with the nickel-chromium alloy foil extending 25 mm from each end in the length direction. The lamination is performed at 120°C using a roller with a linear pressure of 5 kg / cm. Then, adhesive layer a1, cut to arbitrary widths with a length of 50 mm, is laminated onto the surface of the molten softened layer c where the release liner has been removed. Next, an adhesive layer a2, cut to any width and 50 mm in length, is bonded to the opposite side of the nickel-chromium alloy foil to which the melt-softened layer c and adhesive layer a1 are bonded. Lamination is then performed from the upper surface of the release liner using a roller with a linear pressure of 5 kg / cm, causing both ends of the nickel-chromium alloy foil to extend 25 mm from the outer periphery of the melt-softened layer c and adhesive layers a1 and a2 along the length of the nickel-chromium alloy foil. Thus, a laminate with a total thickness of 160 μm excluding the release liner is formed, consisting of adhesive layer a1, melt-softened layer c, nickel-chromium alloy foil, and adhesive layer a2 stacked sequentially. This laminate is then cured at 40°C for 48 hours and cut to a width of 2 mm to obtain the intermediate layer (A-7). The intermediate layer (A-7) is configured as follows: the melt softening layer c and the adhesive layers a1 and a2 are 2 mm wide and 50 mm long, and the nickel-chromium alloy foil is 2 mm wide and 100 mm long. The nickel-chromium alloy foil has a pair of protrusions extending from the outer periphery of the melt softening layer c and the adhesive layers a1 and a2.

[0185] Prepare two laminates (T-2) of arbitrary width, each 50 mm in length, prepared in Example 1. The two laminates (T-2) are sandwiched between the intermediate layer (A-7) with the foam layer in contact with both sides of the intermediate layer (A-7). The ends of the molten softening layer c and the adhesive layers a1 and a2 are aligned with the ends of the two laminates (T-2). The two laminates (T-2) are then pressed onto the intermediate layer A (A-7) from the upper surface of the release liner using a roller with a linear pressure of 5 kg / cm, resulting in the adhesive tape of Example 7 with a total thickness of 460 μm.

[0186] Regarding the adhesive tape of Example 7, excluding the release liner, the layer configuration consists of adhesive layer B1, insulation layer C, adhesive layer a1, melt-softening layer c, heating element b, adhesive layer a2, insulation layer C, and adhesive layer B1 stacked sequentially. Melt-softening layer c includes a hot-melt adhesive, adhesive layers a1 and a2, and adhesive layer B1 is a laminate containing a pressure-sensitive adhesive. Furthermore, regarding the adhesive tape of Example 7, the dimensions of the adhesive surface (effective portion) are 2mm wide × 50mm long, and the dimensions of the nickel-chromium alloy foil are 2mm wide × 100mm long. Both ends of the nickel-chromium alloy foil extend from and are positioned around the outer periphery of the melt-softening layer c and adhesive layers a1 and a2. The nominal volume resistivity of the nickel-chromium alloy foil is 108 μΩ·cm, and the measured value is 105 μΩ·cm.

[0187] <Item Crafting> Peeling the adhesive tape of Example 7 ( Figure 9A In section C (represented by reference numeral 10 in the attached drawing), the release liner near the side of the melted softened layer c is adhered to the substrate 90a (glass, 40mm wide × 50mm long × 10mm thick) in a manner that extends 50mm along the length of the substrate 90a and crosses the center of the substrate 90a (refer to the attached drawing). Figure 9A ~C). Next, peel off the release liner on the opposite side of the adhesive tape, so that the object to be adhered 90b (glass, 30mm wide × 100mm long × 2.8mm thick) can be sandwiched in the shape of the adhesive tape 10 (refer to...). Figure 9A ~C) Paste, at 20N / cm 2 Press for 10 seconds. Place the resulting adhesive at 23°C and 50% RH for at least 24 hours to obtain the article of Example 7.

[0188] (Refer to Examples 2-7) In Examples 2-7, the laminate (T-2) is not adhered to either side of the intermediate layer A. Otherwise, the adhesive tapes of Reference Examples 2-7 are obtained in the same manner as in Examples 2-7. Regarding the adhesive tapes of Reference Examples 2-7, the composition excluding the release liner consists only of the intermediate layers (A-2) to (A-7). The total thickness of the adhesive tapes in Reference Examples 2-4 is 110 μm, the total thickness of the adhesive tape in Reference Example 5 is 128 μm, the total thickness of the adhesive tape in Reference Example 6 is 125 μm, and the total thickness of the adhesive tape in Reference Example 7 is 160 μm.

[0189] In addition, the adhesive tape of Reference Examples 2 to 7 was used instead of the adhesive tape of Examples 2 to 7. Otherwise, the articles of Reference Examples 2 to 7 were obtained by the same operation as those of Examples 2 to 7.

[0190] <Evaluation> <<Peeling Time>> Using the articles from Examples 1 to 7 (excluding Example 5) and Reference Examples 1 to 7 (excluding Reference Example 5) as test pieces, in Figure 9B Place 500g / cm in the direction of the arrow shown in ~C. 2 After applying a load L, at 23°C, the protruding portion e of the metal foil (heating element) in the adhesive tape 10 of the test piece was held by an alligator clip 60. Using a dry cell battery and a resistor (manufactured by uxcell, trade name: "Metal Clatt Resistance"), a current was flowed through the test piece at a heat output of 37 J per second. The time until the intermediate layer A peeled off and the adhered object 90a fell off, and the item was removed (peeling time) was measured. In addition, in the evaluation of the items in Example 5 and Reference Example 5, a DC stabilized power supply (manufactured by Kikusui Electronics Industry Co., Ltd., trade name: "PAS160-1") was used instead of a dry cell battery. A current was flowed through the test piece at a heat output of 5.4 J per second. The time until the intermediate layer A peeled off and the adhered object 90a fell off, and the item was removed (peeling time) was measured. The results are shown in Table 1. It should be noted that peeling occurred within the adhesive layer a1 in Examples 1-5 and Reference Examples 1-5. In both Example 6 and Reference Example 6, delamination occurred at the interface between the adhesive layer a1 of intermediate layer A and the metal nonwoven fabric. In both Example 7 and Reference Example 7, delamination occurred within the melt-softened layer c of intermediate layer A.

[0191] <<Insulation: Temperature of the Adherent>> In the determination of peeling time in Examples 1-7 (excluding Example 5) and Reference Examples 1-7 (excluding Reference Example 5), the temperature of the adhered object was measured over time, and the highest temperature reached by the adhered object during disassembly was measured. In the temperature measurement of the adhered object, a thin temperature sensor (device name: ST-50 (K thermocouple), manufactured by RIKEN K.K.) and a recorder (device name: midi LOGGER GL200A, manufactured by Graphtec Co.K.) were used. The thin temperature sensor was placed on the surface (opposite to the tape) of the adhered object (glass, 30mm wide × 100mm long × 2.8mm thick). The metal foil at the adhesive end of the test piece was held with alligator clips. A dry cell battery and a resistor (manufactured by uxcell, trade name: "Metal Clatter Resistance") were used to flow current at a rate of 37J of heat generated per second, and the temperature of the adhered object during disassembly was measured. In addition, in the evaluation of the items in Example 5 and Reference Example 5, a DC stabilized power supply (manufactured by Kikusui Electronics Industry Co., Ltd., trade name: "PAS160-1") was used instead of a dry cell battery to flow current through the test piece at a heat generation of 5.4 J per second, and the temperature of the adhered object during disassembly was measured. The results are shown in Table 1.

[0192] [Table 1] Explanation of reference numerals in the attached figures

[0193] A Intermediate Layer a1, a2, a3 adhesive layers b. Heating element c Melt softening layer e (the protrusion of the heating element) B, B1, B2 adhesive layers C, C1, C2 insulation layers 10, 20, 30, 40, 50 adhesive tape 90 Adhesive 100 items 60 Alligator Clips L load

Claims

1. An adhesive tape, characterized in that, The adhesive tape has the following features: Intermediate layer A, comprising the heating element and adhesive; An adhesive layer B1 disposed on one side of the intermediate layer A and containing adhesive; and An adhesive layer B2, disposed on the other side of the intermediate layer A and containing adhesive, At least one of the adhesive layer B1 and the adhesive layer B2 is a heat-insulating layer C that also has heat-insulating properties; or, the adhesive tape further comprises a heat-insulating layer C at at least any position between the intermediate layer A and the adhesive layer B1, and between the intermediate layer A and the adhesive layer B2. The adhesive tape can be peeled off by heating the heating element within the intermediate layer A or between the intermediate layer A and the layer adjacent to the intermediate layer A.

2. The adhesive tape according to claim 1, wherein, The adhesive tape has the heat insulation layer C at two locations: between the intermediate layer A and the adhesive layer B1, and between the intermediate layer A and the adhesive layer B2.

3. The adhesive tape according to claim 1 or 2, wherein, The insulation layer C is selected from the group consisting of a free foam layer, a hollow layer, and a hollow particle layer.

4. The adhesive tape according to claim 1 or 2, wherein, The thickness of the insulation layer C is 15. μ m~1000 μ m.

5. The adhesive tape according to claim 1 or 2, wherein, The volume resistivity of the heating element is 30. μ Ω·cm or higher.

6. The adhesive tape according to claim 5, wherein, The heating element is selected from the group consisting of nickel-chromium alloy, stainless steel, titanium, nickel silver, and carbon.

7. The adhesive tape according to claim 1 or 2, wherein, The intermediate layer A is a laminate consisting of a planar heating element and adhesive layers a1 and a2 on each surface of the planar heating element.

8. The adhesive tape according to claim 7, wherein, In the top view, the planar heating element has a pair of protrusions extending from the outer periphery of the adhesive layer a1 and the adhesive layer a2.

9. The adhesive tape according to claim 7, wherein, At least one of adhesive layer a1 and adhesive layer a2 is softened or melted by heating.

10. The adhesive tape according to claim 1 or 2, wherein, The intermediate layer A is composed of a single layer containing the heating element and the adhesive.

11. The adhesive tape according to claim 1 or 2, wherein, The intermediate layer A is softened or melted by heating.

12. The adhesive tape according to claim 1 or 2, wherein, The loss tangent of the adhesive layer formed by the adhesive is tan δ Temperatures reaching 0.45 or higher fall within the temperature range of 80°C to 200°C.

13. An article characterized in that, The item comprises: At least two objects to be glued; and The adhesive tape according to any one of claims 1 to 12 between the two adhered objects. The two objects to be bonded are bonded together via the adhesive tape.

14. The article according to claim 13, wherein, In a top view, the adhesive tape has a pair of protrusions extending from the outer periphery of the adhered object.

15. The method for disassembling an article according to claim 13 or 14, characterized in that, The heating element softens or melts the intermediate layer A, thereby separating the two adhered objects.

16. The method for disassembling an article according to claim 15, wherein, The heating element is heated by resistance heating. The intermediate layer A is electrically connected to a power source, and electricity is supplied from the power source to the heating element. The adhesive layer A is softened or melted by resistance heating, thereby separating the two adhered objects.

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