Adhesive tape, article, and method for detaching article

Abstract

The invention relates to an adhesive tape, an article, and a method for detaching the article. The present invention addresses the problem of providing: an adhesive tape which can be thermally peeled off in a short time, can prevent thermal damage to adherends, and is easy to perform a thermal peeling operation; an article in which at least two adherends are adhered via the adhesive tape; and a method for detaching the article. An adhesive tape having at least an adhesive layer, a heat-generating body, and a melt-softening layer adjacent to the heat-generating body in this order, the heat-generating body having an average thickness of 2 [mu] m or more and 200 [mu] m or less, the heat-generating body being a heat-generating body obtained by bonding a conductive filler into a sheet.

Description

TECHNICAL FIELD

[0001] The present application relates to an adhesive tape ("adhesive" in Japanese is "sticky"), an article, and a method for disassembling the article. In detail, the present application relates to an adhesive tape which can be applied in various fields such as manufacturing of electronic devices, an article having a structure bonded by the adhesive tape, and a method for disassembling the article. BACKGROUND

[0002] The adhesive tape is used for a component fixing purpose, a temporary fixing purpose of components, a label purpose of displaying product information, and the like in various industrial fields such as OA equipment, IT products, home electric appliances, automobiles, and the like, as a joining means which is excellent in workability and high in bonding reliability. In recent years, from the viewpoint of protecting the global environment, the demand for recycling and reuse of used products is increasing in these various industrial fields such as home electric appliances, automobiles, and the like.

[0003] When recycling and reusing various products, a work of peeling the adhesive tape for fixing of components, labels is required, but since the adhesive tape is provided at various places in the product, it is desired to reduce the work cost by a simple removal process.

[0004] In order to separate the adherends from each other, for example, a hot melt adhesive composition which is rapidly dissolved in a short time by electromagnetic induction heating is proposed (for example, refer to Patent Literature 1).

[0005] As a method for separating the adherends from each other, a method for disassembling a building is proposed in which a metal base material is heated by an electromagnetic induction heating device, an adhesive between the base material and an interior material is heated and foamed to be peeled, and the interior material is peeled from the metal base material (for example, refer to Patent Literature 2).

[0006] In addition, a double-sided adhesive tape having a heat conductive layer is proposed in which the double-sided adhesive tape can be easily disassembled by directly heating the heat conductive layer by contact with a heat generation source (for example, refer to Patent Literature 3).

[0007] PRIOR ART DOCUMENTS PATENT LITERATURE Patent Literature 1: Japanese Patent Application Laid-Open No. 2002-188068 Patent Literature 2: Japanese Patent Application Laid-Open No. 2006-200279 Patent Literature 3: Japanese Patent Application Laid-Open No. 2016-108394 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION However, in the conventional method of peeling and detaching by heating, since heat is applied from the outside, if the amount of heat generated from the heat generator is desired to be the amount of heat required for peeling the adhesive tape, there is a case where the adherend is thermally deteriorated or damaged due to the generated heat. On the other hand, if thermal deterioration or damage of the adherend is desired to be suppressed, there is a case where the amount of heat generated is reduced and the adhesive tape is not sufficiently heated, so that peeling is difficult to occur.

[0008] Therefore, in the adhesive tape in which adherends such as rigid bodies are fixed to each other, an adhesive tape having a function of detaching and reusing a member as an adherend is desired, and an adhesive tape having a function of being simply detached and peeled by heating is more desired.

[0009] An object of the present application is to provide an adhesive tape capable of heating and peeling in a short time, capable of preventing thermal damage of an adherend, and easy to operate, an article having a configuration bonded by the adhesive tape, and a detaching method of the article.

[0010] Technical solution for solving the technical problem The present application relates to the following (1) to (14).

[0011] (1) An adhesive tape having at least, in order, an adhesive layer, a heat generator, and a fusion softening layer adjacent to the heat generator, the average thickness of the heat generator being 2 μ μm or more and 200 μ μm or less, the heat generator being a heat generator obtained by bonding and sheeting an electrically conductive filler.

[0012] (2) The adhesive tape according to (1), wherein the volume resistivity of the heat generator at 20°C is 50 μ Ω-cm or more.

[0013] (3) The adhesive tape according to (1) or (2), wherein the heat generator is a heat generator obtained by bonding and sheeting an electrically conductive filler in a fibrous or particulate form, and further impregnating a binder.

[0014] (4) The adhesive tape according to any one of (1) to (3), wherein the heat generator is a heat generator obtained by bonding and sheeting an electrically conductive filler in a fibrous or particulate form and an organic filler.

[0015] (5) The adhesive tape according to any one of (1) to (4), wherein the heat generator is a heat generator obtained by sintering and sheeting an electrically conductive filler in a fibrous or particulate form.

[0016] (6) The adhesive tape according to any one of (1) to (5), wherein the electrically conductive filler is selected from a metal, an alloy, and carbon.

[0017] (7) The adhesive tape according to any one of (1) to (6), wherein the heat generating body has one pair of protrusions that protrude from the outer periphery of the adhesive layer and the fusion-softening layer in a plan view.

[0018] (8) The adhesive tape according to any one of (1) to (7), wherein the adhesive layer is further provided on the side of the opposite face of the fusion-softening layer to the face adjacent to the heat generating body.

[0019] (9) The adhesive tape according to any one of (1) to (8), wherein the fusion-softening layer is peeled by heating.

[0020] (10) The adhesive tape according to any one of (1) to (9), wherein the heat generating body is an electrically conductive body that generates heat by electric conduction, and the adhesive tape is peeled by the heat generation of the electrically conductive body.

[0021] (11) An article comprising at least two adherends and the adhesive tape according to any one of (1) to (10) between the two adherends, the two adherends being bonded via the adhesive tape.

[0022] (12) The article according to (11), wherein the heat generating body constituting the adhesive tape has one pair of protrusions that protrude from the outer periphery of the adherend in a plan view.

[0023] (13) A disassembly method of the article according to (11) or (12), wherein the fusion-softening layer is fused and / or softened by heating of the heat generating body, thereby separating the two adherends.

[0024] (14) The disassembly method of the article according to (13), wherein the heating of the heat generating body is resistance heating, the heat generating body is electrically connected to a power source, the heat generating body is electrically conducted from the power source, the fusion-softening layer is fused and / or softened by the resistance heating, thereby separating the two adherends.

[0025] Effects of the Invention According to the present application, an adhesive tape that can be peeled by heating in a short time, can prevent thermal damage to the adherend, and is easy to operate can be provided.

[0026] In addition, according to the present application, an article in which at least two adherends are bonded via the adhesive tape, and a disassembly method of the article can be provided, thermal degradation to the adherend such as an electronic component can be suppressed, recycling is possible, and disassembly work becomes easy. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic cross-sectional view showing one example of the adhesive tape of the present application.

[0028] Figure 2 is a schematic cross-sectional view showing another example of the adhesive tape of the present application.

[0029] Figure 3 is a schematic plan view showing another example of the adhesive tape of the present application.

[0030] Figure 4 is a schematic plan view showing an example of a pattern of the heat-generating body in the adhesive tape of the present application.

[0031] Figure 5 is a schematic cross-sectional view showing another example of the adhesive tape of the present application.

[0032] Figure 6 is a schematic plan view showing an example of the article of the present application.

[0033] Figure 7 is a schematic cross-sectional view showing an example of the article of the present application.

[0034] Figure 8 is a view schematically showing a disassembly method of the article of the present application.

[0035] Figure 9 is a schematic plan view of the adhesive tape of Example 1.

[0036] Figure 10 is a schematic cross-sectional view of the adhesive tape of Example 1.

[0037] Figure 11 is a schematic plan view showing an example of the article of the present application, and an evaluation method.

[0038] Figure 12 is a schematic front view showing an example of the article of the present application, and an evaluation method.

[0039] Figure 13 is a schematic side view showing an example of the article of the present application, and an evaluation method. DETAILED DESCRIPTION

[0040] Hereinafter, the embodiments of the present application will be explained in detail. It should be noted that in the present specification, a numerical range represented by "to" indicates a range including the numerical values recited before and after "to" as the minimum value and the maximum value, respectively.

[0041] 1. Adhesive tape The present application is an adhesive tape having at least an adhesive layer, a heat-generating body, and a fusion softening layer adjacent to the heat-generating body in this order, wherein the average thickness of the heat-generating body is 2 μ or more and 200 μ or less, and the heat-generating body is a heat-generating body obtained by bonding and sheeting an electrically conductive filler.

[0042] The adhesive tape of the present application can be used as an easily detachable adhesive tape which, after being attached to an adherend and fixed between adherends, can be easily separated or detached after a certain period of time.

[0043] Since the adhesive tape of the present application has the above-described configuration, it can maintain a high adhesive force when fixed between adherends, and can be easily separated or detached by heating when the adherends are separated or detached, regardless of the material of the adherends. Note that "separation or detachment" is simply referred to as "detachment" hereinafter.

[0044] The adhesive tape of the present application has a heating element. The heating element is heated by a heating means such as direct current, induction heating, infrared rays, microwaves, or the like from the outside, and the molten and softened layer adjacent to the heating element is molten or softened.

[0045] In the present application, in order to be able to suppress the deterioration of the adherend caused by the irradiation of energy from the outside and to be able to perform detachment of the article in a state in which the adhesive tape is built in the article, the heating element is preferably a current-carrying element which is heated by current, and the adhesive tape of the present application is preferably of a type which is peeled by the heating of the current-carrying element.

[0046] Here, the average thickness of the heating element of the adhesive tape of the present application is 2 μ μm or more and 200 μ μm or less, and the heating element is a heating element obtained by bonding and sheeting an electrically conductive filler, whereby the volume resistivity thereof can be increased. In detail, by adopting a design in which the average thickness of the heating element is made thin, a tendency to increase the volume resistivity can be obtained.

[0047] That is, the effect of increasing the amount of heat generated by the heating element by applying a smaller current is exerted. By the above effect, the thermoplastic resin constituting the molten and softened layer can be efficiently molten or softened.

[0048] Therefore, the adhesive tape of the present application has a sufficient initial adhesive force in the vicinity of room temperature (0 to 40°C), and the adhesive strength decreases with heating by the heat from the heating element, the residual adhesive force after current application is small with respect to the initial adhesive force, and the reduction rate of the adhesive force by current application is large. Therefore, the detachability of an article made using the adhesive tape of the present application is excellent.

[0049] In addition, even in the case where the operator accidentally contacts the current application portion during detachment work, the adhesive tape of the present application can obtain a sufficient amount of heat with a low current to the extent that no physical impact is caused on the operator. Therefore, the work safety of the detachment method of the present application is excellent.

[0050] In other words, the adhesive tape of the present application causes heat generation inside the tape, and thus, when the article formed by bonding at least two adherends via the adhesive tape of the present application is disassembled, heat damage to the adherends can be reduced, and the article can be easily disassembled.

[0051] Further, even in the case of an article formed by embedding electronic components in a device, and thus, the adhesive tape cannot be contacted and the article is completely shielded from the outside, the electronic components can be easily disassembled from each other without preparing a large-scale device. In particular, in the case of disassembling the adhesive tape by heating using a driving current in the electronic components in a state of being embedded in an electronic device, heat deterioration of a circuit in the electronic components can be prevented, and the heating peeling can be performed without an external device, and thus, the disassembling work becomes easy.

[0052] The mode in which the adhesive tape of the present application "can be peeled by heating" can be a mode in which, by heating, the molten softening layer itself is molten or softened, and cohesive failure occurs inside the molten softening layer, and further, a part or the whole of the adhesive tape is peeled from the adherend, or a mode in which, by heating, the molten softening layer itself is molten or softened, and the adhesive force thereof is reduced, and peeling (interface failure) occurs between the molten softening layer and a layer adjacent to the molten softening layer or the adherend, and further, a part or the whole of the adhesive tape is peeled from the adherend.

[0053] Further, when the adhesive tape is peeled by heating, the molten softening layer can be peeled as a whole from the adherend, or a part of the molten softening layer can be peeled from the adherend.

[0054] Further, as described later, the adhesive layer constituting the adhesive tape of the present application is composed of a component which is less likely to be molten or softened by heating than the component constituting the molten softening layer.

[0055] Thus, the adhesive tape of the present application can heat the molten softening layer to be selectively molten or softened, and further, peeled, by causing the heating body to generate heat.

[0056] Hereinafter, the structure of the adhesive tape of the present application will be described.

[0057] [Heating Body] The average thickness of the heating body in the adhesive tape of the present application is 2 μ m or more and 200 μ The heating body in the adhesive tape of the present application is a heating body obtained by bonding and sheeting an electrically conductive filler.

[0058] The temperature rise of the heating body in the adhesive tape of the present application when a current of 0.5 A is applied to the heating body for 30 seconds is preferably in the range of 120°C or more, and more preferably 150°C or more.

[0059] If the adhesive tape of the present application has a heat-generating body having the above-described properties in its constitution, when an article formed by adhering at least two adherends via the adhesive tape of the present application is disassembled, heat damage to the adherends can be reduced, and the article can be easily disassembled.

[0060] As the conductive filler, a filler selected from the group consisting of a metal, an alloy, and carbon is preferable. As the metal, silver, iron, copper, aluminum, nickel, titanium, chromium, platinum, gold, palladium, rhodium, iridium, ruthenium, and the like can be exemplified.

[0061] As the alloy, for example, stainless steel such as SUS410, SUS304, SUS430, and the like; an alloy of two or more kinds of metals such as brass, white copper, bronze, nickel-chromium alloy, nickel-silver, and the like can be exemplified. As the carbon, for example, carbon nanomaterials such as graphite, graphene, graphene oxide, carbon nanotube, graphene platelet, carbon nanofiber, and the like can be exemplified.

[0062] The conductive filler can be used alone or in combination of two or more kinds.

[0063] Among them, as the conductive filler, a filler selected from the group consisting of silver, stainless steel, and carbon is more preferable.

[0064] The conductive filler is preferably in a fibrous or particulate shape.

[0065] In the case where the conductive filler is in a fibrous shape, from the viewpoint of easily obtaining the fibrous conductive filler to be described later, which is made into a nonwoven fabric, the average fiber diameter thereof is preferably in the range of 0.01 μ m to 30 μ The range of m is more preferably in the range of 0.02 μ m to 20 μ The range of m.

[0066] The cross-sectional shape perpendicular to the length direction of the fiber can be any shape such as a circular shape, an elliptical shape, a substantially quadrangular shape, an indefinite shape, and the like. The "average fiber diameter" in the present specification means the average value of the area diameters derived by calculating the cross-sectional area in an arbitrary perpendicular cross-section with respect to the length direction of 20 fibrous conductive fillers photographed using a microscope, and calculating the diameter of a circle having the same area as the cross-sectional area.

[0067] In the case where the conductive filler is in a fibrous shape, from the viewpoint of easily improving the homogeneity of the fibrous conductive filler to be described later, which is made into a nonwoven fabric, the average fiber length thereof is preferably in the range of 0.01 mm to 10 mm, and more preferably in the range of 0.03 mm to 5 mm. The "average fiber length" in the present specification means the average value obtained by measuring 20 fibrous conductive fillers photographed using a microscope.

[0068] In the case where the electrically conductive filler is fibrous, the aspect ratio thereof is preferably 33 to 10,000, more preferably 150 to 1,500.

[0069] In the case where the electrically conductive filler is particulate, the shape of the particles can be exemplified by a spherical shape, a scale shape, a lamellar shape, a blade shape, a columnar shape, an isometric shape, a leaf shape, a flat plate shape, a wedge shape, a rosette shape, and the like, and is not particularly limited.

[0070] In the case where the electrically conductive filler is particulate, the particle diameter (average particle diameter) thereof is preferably 0.01 μ m to 500 μ more preferably 0.02 μ m to 200 μ in the range of 0.05 μ m to 100 μ in the range of 0.05. Note that the particle diameter of the particulate electrically conductive filler is a value of the median particle diameter (D50) measured by a laser diffraction / scattering type particle size distribution measuring device.

[0071] As the bonding method of the electrically conductive filler, there can be exemplified firing, chemical etching, laser welding, IH heating, chemical bonding, thermal bonding, and the like.

[0072] In the case where the electrically conductive filler is, for example, in a state in which silver nanoparticles or silver nanowires of a silver nano-ink like that are dispersed in a dispersion medium, a sheet-like electrically conductive filler, that is, a heating element, can be formed by applying the above-mentioned ink to a substrate and drying it, and then applying the bonding method.

[0073] Here, the electrically conductive filler bonding is a state in which the electrically conductive filler is physically fixed, and a site at which the electrically conductive filler is physically fixed is referred to as a bonding portion.

[0074] In the bonding portion, the electrically conductive fillers can be directly fixed to each other, and a part of the electrically conductive fillers can be indirectly fixed to each other via a component other than a metal component.

[0075] Among them, from the viewpoint of easily and reliably performing bonding, the electrically conductive fillers being fixed to each other, and the coefficient of variation (CV value) of the basis weight in the heating element, which is defined by JIS Z8101 (ISO3534), being easily stable, as the bonding method, firing is preferred.

[0076] That is, the heating element is preferably a heating element formed by firing and sheeting the electrically conductive filler in a fibrous or particulate form, and the electrically conductive filler in a fibrous form made into a nonwoven fabric is preferably fired.

[0077] Note that as a method of producing a nonwoven fabric from a fibrous conductive filler, a dry method of compressing a fibrous conductive filler or a web mainly composed of a fibrous conductive filler using a carding method, an air-laying method, or the like can be given. A wet papermaking method of preparing a slurry by dispersing a fibrous conductive filler in water, casting the slurry into a sheet shape, and then performing each process of dewatering, pressing, and drying can also be given.

[0078] The firing is preferably performed in a vacuum or a non-oxidizing atmosphere at a temperature lower than the melting point of the material (metal, alloy) constituting the conductive filler.

[0079] Further, the heat-generating body in the adhesive tape of the present application is more preferably a heat-generating body obtained by bonding and sheeting a fibrous or particulate conductive filler, and further impregnating a binder.

[0080] In the case of the above heat-generating body, the adhesive layer and the heat-generating body, and the fusion-softening layer and the heat-generating body have a tendency to increase the interlayer adhesive strength, and are thus preferable from the viewpoint of easily improving the performance of the adhesive tape.

[0081] As the above binder, an organic binder such as an epoxy resin, an acrylonitrile-butadiene copolymer resin, an unsaturated polyester resin, a phenol resin, a melamine resin, a polyimide resin, a polyurea resin, a polyurethane resin, and the like; and an inorganic binder such as colloidal silica, water glass, sodium silicate, and the like can be given. Among these, an acrylonitrile-butadiene copolymer resin and a phenol resin are preferable, and a resol-type phenol resin is more preferable.

[0082] As the heat-generating body obtained by bonding and sheeting a fibrous or particulate conductive filler, and further impregnating a binder, a carbon-based sheet can be used.

[0083] As the carbon-based sheet, for example, a graphite sheet obtained by using carbon fibers and carbon particles such as graphite as a conductive filler, and using the above resin, preferably a resol-type phenol resin, as a binder can be given.

[0084] Further, the heat-generating body in the adhesive tape of the present application is preferably a heat-generating body obtained by bonding and sheeting the above fibrous or particulate conductive filler and an organic filler.

[0085] In the case of the above heat-generating body, it is preferable from the viewpoint of easily controlling the volume resistivity of the heat-generating body to be in a suitable range described later, and easily improving the performance of the adhesive tape.

[0086] As the above-mentioned organic filler, there can be mentioned a cellulose-based filler derived from wood pulp, rice husk, cotton, bamboo, kenaf, hemp, and the like; a filler of a heat-resistant resin such as liquid crystal polyester, an aromatic polyamide, nylon, and the like. The organic filler can be fibrous or particulate, and the preferable ranges of the average fiber diameter, the average fiber length, and the average particle diameter thereof are preferably the same as those of the above-mentioned electrically conductive filler.

[0087] In the case where the electrically conductive filler and the organic filler are bonded and sheeted to constitute the heat-generating body, the content of the organic filler with respect to the entire heat-generating body is preferably in the range of 0.01 to 60% by mass, and more preferably in the range of 0.01 to 40% by mass.

[0088] As the heating of the heat-generating body and the heating means, there can be mentioned, for example, resistance heating, electromagnetic induction heating, infrared heating, microwave heating, and heat conduction.

[0089] Among them, from the viewpoint that the molten softened layer can be sufficiently softened or molten even with a small amount of energy, for example, the adhesion tape can be heated and detached using the driving current within the electronic component in a state of being built in the electronic device, and from the viewpoint that the heat-generating body does not need to be heated by an external heat source through the adherend, and the over-heating of the adherend can be prevented, resistance heating is preferable.

[0090] Here, "resistance heating" refers to one of the electric heating methods, and is a method in which an electric current is passed through an electrically conductive body (heat-generating body) having an electric resistance, and the electrically conductive body is heated using the Joule heat thereof. If a constant electric current is passed through the electrically conductive body, the amount of Joule heat generated in a certain time is proportional to the square of the size of the electric current and the electric resistance of the wire (Joule's law). The electrically conductive body has an electric resistance value (volume resistivity or the like) inherent to the substance thereof.

[0091] "Electromagnetic induction heating" refers to one of the non-contact heating methods in the electric heating methods, and is also called high-frequency induction heating. If an electrically conductive body (heat-generating body) having an electric resistance is placed in a magnetic field generated by flowing a high-frequency current (alternating current) through a wire in a coil shape, an electric current flows through the electrically conductive body according to the principle of electromagnetic induction, and the electrically conductive body is heated using the Joule heat thereof.

[0092] "Infrared heating" and "microwave heating" refer to non-contact heating methods using electromagnetic waves in a specific wavelength region such as infrared rays and microwaves, and using heat energy based on radiation.

[0093] The bonds of atoms and the molecules constituting a substance perform thermal vibration (molecular motion, lattice vibration of a crystal) corresponding to the temperature inherent to the substance, and if electromagnetic waves of a wavelength corresponding to the vibration frequency are absorbed, the vibration of the molecules becomes intense and heat is generated.

[0094] "Thermal conduction" is a heating method using a heat transfer phenomenon in which heat transfers from a high temperature side to a low temperature side inside a solid, and enables heat to be transferred while a heat source is directly in contact with a material having excellent thermal conduction.

[0095] In the case where the heating means is resistance heating, the volume resistivity of the heat generating body at 20°C is preferably 50 μ Ω·cm or more, more preferably 70 μ Ω·cm or more, further preferably 100 μ Ω·cm or more. From the viewpoint of not excessively increasing the voltage required when current is supplied to the heat generating body, the volume resistivity of the heat generating body at 20°C is preferably 100000 μ Ω·cm or less, more preferably 20000 μ Ω·cm or less, further preferably 10000 μ Ω·cm or less, particularly preferably 5000 μ Ω·cm or less. Specifically, the volume resistivity of the heat generating body can be in the range of 50 to 100000 μ Ω·cm, 50 to 20000 μ Ω·cm, 70 to 10000 μ Ω·cm, 100 to 5000 μ Ω·cm.

[0096] If the volume resistivity of the heat generating body is 50 μ Ω·cm or more, the adhesive tape can be heated only, and high-temperature deterioration of the wiring circuit can be prevented when the heat generating body is supplied with the driving current of the electronic device by being connected to the wiring circuit in the electronic device, and the like.

[0097] In addition, if a heat generating body having a volume resistivity in the above range is used, the molten softened layer can be melted or softened in a short time, and the dismounting time can be shortened.

[0098] Furthermore, when the driving current in the electronic component is used, excessive heating of the electronic circuit and the connection portion due to the supply of current to the heat generating body can be prevented, and thermal deterioration of the electronic component can be prevented.

[0099] The volume resistivity of the heat generating body can be measured at 20°C in accordance with JIS K 7194 using a low resistivity meter (manufactured by Soto Kagaku Analytech Co., Ltd., trade name "Loresta-AX MCT-T370") and a four-probe probe (manufactured by Soto Kagaku Analytech Co., Ltd., trade name "ASP Probe MCP-TP03P"). The number of measurement points is set to 1 point measurement, and the resistivity correction coefficient is 4.532.

[0100] The heat generating body obtained by bonding and sheeting the electrically conductive filler can be in a mesh shape, and is usually in a planar shape. If the heat generating body is in a planar shape, it can be sufficiently bonded to a molten and softened layer before energization, the molten and softened layer being in contact with the heat generating body, and heat is generated on the surface during energization, whereby the heat generating body itself is less likely to be damaged or broken when peeled off after energization.

[0101] As the heat generating body in a planar shape, a heat generating body obtained by bonding and sheeting the electrically conductive filler in a fibrous or particulate shape, preferably the electrically conductive filler in a fibrous shape formed into a nonwoven fabric, by firing, and more preferably a heat generating body obtained by bonding and sheeting the electrically conductive filler in a fibrous or particulate shape and further impregnating a bonding agent, is preferable.

[0102] The heat generating body in a planar shape can be shaped in a pattern shape, or can be in a strip shape or a line shape (see the description of the heat generating body in a strip shape or a line shape described later). Figure 4 If the heat generating body is in a strip shape or a line shape, the heat generating efficiency is high, and the contact area with the adherend is small, and thus it is advantageous in terms of easy peeling. In this case, the length in the short axis direction of the heat generating body (strip width or line width) is preferably 0.5 to 20 mm, more preferably 1 to 10 mm, and further preferably 2 to 5 mm.

[0103] If the heat generating body in a planar shape is in a pattern shape (has a pattern shape), the distance between the terminals (terminals for connection to a power source) of the heat generating body can be lengthened, and the resistance can be increased.

[0104] Thus, the heat generating efficiency of the heat generating body in a planar shape is increased, and the adhesive tape of the present application can be peeled off in a short time. The pattern width in the case where the heat generating body in a planar shape is in a pattern shape is not particularly limited, and can be the same as the preferable range of the strip width described above.

[0105] In the heat generating body in a planar shape, the heat generating body can be arranged on one side or both sides of the base material. In this case, the heat generating body is arranged in direct contact with one side or both sides of the base material. In addition, the heat generating body can be arranged so as to cover the entire area of one side or both sides of the base material, or can be arranged in a line shape, a strip shape, or a pattern shape.

[0106] As the base material, there is no particular limitation as long as it can support the heat generating body, and from the viewpoints of the followability of the adhesive tape, thinning, heat resistance, and the like, a film of a polyester such as polyethylene terephthalate or polyethylene naphthalate; a polyolefin such as polypropylene; or a resin such as polyimide is preferable.

[0107] The average thickness of the heat generating body is preferably 2 μ μm or more and 200 μ μm or less, more preferably 5 μ μm or more, and further preferably 10 μ μm or more. On the other hand, the average thickness of the heat generating body is preferably 200 μm, more preferably 150 μ m. From the viewpoint of easily increasing the volume resistivity of the heat generating body, and easily obtaining sufficient heat generation of the adhesive tape of the present application even at a low current, the average thickness of the heat generating body is preferably 10 to 150 μ m.

[0108] If the average thickness of the planar heat generating body is in the above range, sufficient current amount and heat generation can be obtained, the heat generating body can be efficiently heated by resistance heating, and the adhesive tape is excellent in followability and adhesion workability.

[0109] Note that the average thickness of the planar heat generating body is an average value obtained by measuring the thickness of 5 or more places selected at random. In the case where the planar heat generating body is a type in which the heat generating body is disposed on one face or both faces of the base material, the average thickness of the planar heat generating body refers to the thickness excluding the base material, and in the case where the heat generating body is disposed on both faces of the base material, it refers to the thickness of the heat generating body of each single face.

[0110] The heat generating body obtained by sintering and sheeting the fibrous or particulate conductive filler, or the heat generating body obtained by sheeting the fibrous or particulate conductive filler and further impregnating the binder can also use a commercially available product, and for example, "Stainless Steel Fiber Sheet" manufactured by Batsuan Seizo Co., Ltd., and "PGS Graphite Sheet" manufactured by Matsushita Electric Industrial Co., Ltd. can be mentioned. In addition, a heat generating body formed by pattern-molding them can also be used.

[0111] [Adhesive layer] In the adhesive tape of the present application, the component constituting the adhesive layer can be, for example, an acrylic adhesive, a urethane adhesive, a rubber-based adhesive such as a synthetic rubber-based or a natural rubber-based adhesive, a silicone-based adhesive, a vinyl ether-based adhesive, and the like. Among them, an adhesive capable of being used as a pressure-sensitive adhesive is preferred, and an acrylic adhesive containing an acrylic polymer is more preferred. The acrylic adhesive containing an acrylic polymer is less likely to melt or soften due to heating.

[0112] Therefore, by the heat generated from the heat generating body of the adhesive tape of the present application, the fusion-softening layer to be described later, which the adhesive tape of the present application has, is selectively fused or softened. Note that the pressure-sensitive adhesive refers to an adhesive that is adhered by applying pressure for a short time at room temperature around 20°C, and has tackiness at ordinary temperature.

[0113] As the acrylic polymer, a homopolymer of a (meth)acrylate monomer, a copolymer of a (meth)acrylate monomer and another monomer, or the like can be exemplified. In the present specification, "(meth)acrylic acid" is a term for acrylic acid, methacrylic acid, and both of them. "(Meth)acrylate" is a term for acrylate, methacrylate, and both of them.

[0114] As the (meth)acrylate monomer, for example, (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid propyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid hexyl ester, (meth)acrylic acid cyclohexyl ester, (meth)acrylic acid octyl ester, (meth)acrylic acid-2-ethylhexyl ester, (meth)acrylic acid isononyl ester, (meth)acrylic acid isodecyl ester, (meth)acrylic acid lauryl ester, and the like (meth)acrylic acid alkyl esters having an alkyl chain of 1 to 14 carbon atoms can be exemplified.

[0115] The acrylic polymer can contain one of these monomers in the structural unit, or two or more of them.

[0116] The content of the (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 further preferably in the range of 90 to 97% by mass, relative to the total content of the monomers constituting the acrylic polymer.

[0117] In addition, as the other monomer for obtaining the acrylic polymer, a monomer containing a polar group can be contained. As the monomer containing a polar group, for example, (meth)acrylic acid, itaconic acid, itaconic anhydride, maleic acid, maleic anhydride, crotonic acid, and the like carboxylic acids having an ethylenic unsaturated group; (meth)acrylic acid-2-hydroxyethyl ester, (meth)acrylic acid hydroxypropyl ester, (meth)acrylic acid-4-hydroxybutyl ester, caprolactone-modified (meth)acrylic acid ester, polyoxyethylene (meth)acrylic acid ester, polyoxypropylene (meth)acrylic acid ester, and the like (meth)acrylic acid esters having a hydroxyl group; (meth)acrylonitrile, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, N-vinyl lauryl lactam, (meth)acryloyl morpholine, (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, (meth)acrylic acid-N,N-dimethylamino methyl ester, acrylic acid-2-(perhydrophthaloyl-N-yl)ethyl ester, and the like nitrogen-containing monomers having an ethylenic unsaturated group can be exemplified.

[0118] In the case of using the crosslinking agent described later, from the viewpoint of being able to form a crosslinking structure between the hydroxyl group, the carboxyl group, and the crosslinking agent, and being able to adjust the storage modulus of the adhesive layer, as the monomer containing a polar group, a (meth)acrylate having a hydroxyl group, a carboxylic acid having an ethylenic unsaturated group, more preferably (meth)acrylate-2-hydroxyethyl, (meth)acrylate-4-hydroxybutyl, (meth)acrylate-6-hydroxyhexyl, acrylic acid are preferable.

[0119] The content of the monomer containing a polar group in the acrylic polymer 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, relative to the total components of the monomers constituting the acrylic polymer.

[0120] The weight average molecular weight of the acrylic polymer is preferably in the range of 400 to 1,400, more preferably in the range of 600 to 1,200, and further preferably in the range of 650 to 1,100. Here, the weight average molecular weight is the weight average molecular weight converted to standard polystyrene, which is measured by gel permeation chromatography (GPC). Specifically, as the GPC measuring device, "SC8020" manufactured by Tosoh Corporation is used, and the measurement is performed under the following measurement conditions.

[0121] • Sample concentration: 0.5% by mass (tetrahydrofuran solution) • Sample injection amount: 100 μ L • Eluent: tetrahydrofuran (THF) • Flow rate: 1.0 mL / minute • Column temperature (measurement temperature): 40°C • Column: "TSKgel GMHHR-H" manufactured by Tosoh Corporation • Detector: differential refractometer The adhesive layer can further contain a tackifying resin for the purpose of adjusting the adhesiveness. As the tackifying resin, various tackifying resins such as rosin-based, polymerized rosin-based, polymerized rosin ester-based, rosin phenol-based, stabilized rosin ester-based, disproportionated rosin ester-based, hydrogenated rosin ester-based, terpene-based, terpene phenol-based, petroleum resin-based, C5 / C9 petroleum resin-based, (meth)acrylate-based, and the like can be exemplified. In addition, a tackifying resin that is liquid at room temperature such as a process oil, a polyester-based tackifying resin, a low molecular weight liquid rubber such as polybutene, and the like can also be used.

[0122] In the case where the adhesive layer contains a tackifying resin, from the viewpoint of obtaining good adhesiveness at around room temperature (0 to 40°C) and being able to exert thermal durability, the amount of the tackifying resin is preferably in the range of 1 to 150 parts by mass, more preferably in the range of 10 to 150 parts by mass, relative to 100 parts by mass of the base resin such as an acrylic polymer that constitutes the adhesive layer. In the case where the adhesive layer contains a tackifying resin, the total content of the base resin and the tackifying resin in the adhesive that forms the adhesive layer is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 90% by mass or more, relative to the total amount of the solid components of the adhesive.

[0123] For the purpose of improving cohesion, the adhesive layer can further contain a crosslinking agent. As the crosslinking agent, for example, known crosslinking agents such as isocyanate-based, epoxy-based, aziridine-based, polyvalent metal salt-based, metal chelate-based, ketone-hydrazine-based, oxazoline-based, carbodiimide-based, silane-based, and glycidyl (alkoxy) epoxy silane-based crosslinking agents can be given.

[0124] In a range not impairing the effects of the present application, the adhesive layer can further contain, as needed, an antioxidant, an anti-aging agent, a coloring agent such as a pigment and a dye, a thickening agent, a leveling agent, a film-forming aid, an infrared absorber, an ultraviolet absorber, a water repellent, and other additives.

[0125] The adhesive layer can be in a manner further containing a thermoplastic resin, and in the adhesive tape of the present application, from the viewpoint of selectively melting or softening the molten softening layer by heat generated from a heat-generating body, it is preferable to be in a manner constituted by a component that is not easily melted or softened by heating and is different from the thermoplastic resin contained in the molten softening layer.

[0126] More specifically, for example, it is preferable to be in a manner containing a thermoplastic resin whose tan δ ) becomes 0.8 or more at a temperature higher than the melting point of the molten softening layer described later in a temperature range of 40°C or higher.

[0127] From the viewpoint of adhesion retention to an adherend and film uniformity at the time of solution coating, the thickness of the adhesive layer is preferably in the range of 10 to 200 μ m, and more preferably in the range of 20 to 100 μ m. Note that the thickness of the adhesive layer is set as an average value obtained by measuring the thickness at any 5 places.

[0128] The melting point of the adhesive layer is preferably higher than the melting point of the molten softening layer described later. Here, the "melting point of the adhesive layer" refers to the melting point of a composition (hereinafter, simply referred to as "adhesive layer composition") composed of an acrylic adhesive, a urethane adhesive, a rubber-based adhesive, a silicone-based adhesive, a vinyl ether-based adhesive, and the like constituting the adhesive layer, and a tackifying resin, a crosslinking agent, other additives, and a thermoplastic resin different from the thermoplastic resin contained in the molten softening layer, and the like, as necessary.

[0129] The melting point of the adhesive layer (adhesive layer composition) is, for example, preferably 130°C or higher, and more preferably in the range of 130°C to 200°C. By adjusting the melting point of the adhesive layer to the above range and adjusting the melting point of the molten softening layer to the range described later, the melting or softening of the molten softening layer can be caused prior to the melting or softening of the adhesive layer using the heat generated by the heat generating body.

[0130] That is, when the article having a constitution bonded by the adhesive tape of the present application is subjected to thermal disassembly, the melting or softening of the molten softening layer can be stably and preferentially caused, and disassembly can be easily performed.

[0131] Note that the "melting point of the adhesive layer" is the temperature of the endothermic peak accompanying the melting of the adhesive layer (adhesive layer composition) measured using differential scanning calorimetry (DSC).

[0132] In the temperature range of 40°C or higher, the tan δ at which the adhesive layer (adhesive layer composition) reaches 0.8 is preferably higher than the tan δ at which the molten softening layer reaches 0.8. Among them, the tan δ at which the adhesive layer (adhesive layer composition) reaches 0.8 is more preferably higher than the tan δ at which the molten softening layer reaches 1.

[0133] Specifically, in the temperature range of 40°C or higher, the tan δ at which the adhesive layer (adhesive layer composition) reaches 0.8 is preferably higher than the tan δ at which the molten softening layer reaches 0.8, and more preferably higher than the tan δ at which the molten softening layer reaches 1, and further preferably higher than the tan δ at which the molten softening layer reaches 1.2.

[0134] As one of the preferable modes of the adhesive layer (adhesive layer composition), the tan δless than 1, more preferably less than 0.8, and further preferably 0.6 or less. From the viewpoint of being able to exert adhesiveness and elasticity from the adhesive layer, the tan δ is preferably 0.2 or more.

[0135] As one of the preferable modes of the adhesive layer, the tan δ The temperature range reaching 0.8 or more is preferably more than 150°C, and more preferably 170°C or more. The upper limit of the above temperature range is not particularly limited, and can be set to 300°C, for example, and is preferably 250°C.

[0136] In the adhesive tape of the present application, if the adhesive layer has such properties, when the adhesive layer and the melt-softening layer receive the same amount of heat from a heat-generating body, the melting and / or softening of the adhesive layer can be inhibited.

[0137] That is, when a product having a constitution bonded by the adhesive tape of the present application is subjected to thermal disassembly, the melting or softening of the adhesive layer can be inhibited while the melting or softening of the melt-softening layer stably and preferentially occurs, and disassembly can be easily performed in a short time.

[0138] Note that, from the viewpoint of being able to exhibit good adhesiveness with respect to a bonded object before and after disassembly, the tan δ is preferably 0.1 to 0.8, and more preferably 0.2 to 0.6.

[0139] The tan δ is measured by dynamic viscoelasticity measurement at a frequency of 1 Hz. For example, a test piece of the adhesive layer composition having a dry thickness of about 2 mm is prepared, and a viscoelasticity tester (ARES-G2, manufactured by TA Instruments Japan, Inc.) is used to measure the storage modulus G' and the loss modulus (G'') at a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a temperature increase rate of 2°C / minute.

[0140] The tan δ is calculated by the formula [tan δ = G'' / G'].

[0141] The tan δ can be adjusted by the kind, combination, and blending ratio of the monomers of the base polymer constituting the adhesive as a main component, such as the above-described acrylic polymer, the blending amount of the tackifying resin added as needed, the addition amount (gel fraction) of the crosslinking agent added as needed, and the like.

[0142] 〔Melt-softening layer〕 The fusion-softening layer of the adhesive tape according to the present application contains a thermoplastic resin.

[0143] <Thermoplastic Resin> As the thermoplastic resin, for example, urethane-based resins, polycarbonates, vinyl chloride-based resins, acrylic-based resins, crystalline or non-crystalline polyester-based resins such as polyethylene terephthalate, polyamide-based resins, styrene-based resins, olefin-based resins, cellulose-based resins, silicone-based resins, fluorine-based resins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, acrylic-based thermoplastic elastomers, urethane-based thermoplastic elastomers, ester-based thermoplastic elastomers, amide-based thermoplastic elastomers, and the like can be given.

[0144] They can be used alone in one kind, or in combination of two or more kinds.

[0145] As the thermoplastic resin, among the above, urethane-based resins, acrylic-based resins, polyester-based resins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, acrylic-based thermoplastic elastomers, urethane-based thermoplastic elastomers, ester-based thermoplastic elastomers, amide-based thermoplastic elastomers are preferred, and styrene-based thermoplastic elastomers are more preferred.

[0146] These thermoplastic resins become capable of fusion or softening by the heat generated from the heat-generating body of the adhesive tape according to the present application, and can be caused to fuse or soften even without containing components such as a heating foaming agent or the like that generate a peeling starting point at the bonding interface, or components for generating a reduction in bonding force.

[0147] Accordingly, the adhesive tape easily becomes capable of peeling, and in addition, it is preferred to have a softening point, and the fusion-softening layer becomes sharply soft by reaching a temperature higher than the softening point, and is easily advantageous in terms of exhibiting high deformability and fluidity.

[0148] As the styrene-based thermoplastic elastomer, a block copolymer containing a polymer block containing a structural unit derived from an aromatic vinyl compound and a polymer block containing a structural unit derived from a conjugated diene compound, or a hydrogenated product thereof is preferred.

[0149] Specifically, mention can be made of: polystyrene-polybutadiene diblock copolymer or polystyrene-poly(ethylene-butylene) diblock copolymer (SEB) as a hydrogenated product thereof, polystyrene-polybutadiene-polystyrene triblock copolymer (SBS) or polystyrene-poly(ethylene-butylene)-polystyrene triblock copolymer (SEBS) as a hydrogenated product thereof, polystyrene-polyisoprene diblock copolymer or polystyrene-poly(ethylene-propylene) diblock copolymer (SEP) as a hydrogenated product thereof, polystyrene-polyisoprene-polystyrene triblock copolymer (SIS) or polystyrene-poly(ethylene-propylene)-polystyrene triblock copolymer (SEPS) as a hydrogenated product thereof, polystyrene-polybutadiene-polystyrene-polybutadiene tetrablock copolymer (SBSB) or a hydrogenated product thereof, polystyrene-polybutadiene-polystyrene-polybutadiene-polystyrene pentablock copolymer (SBSBS), styrene-based multi-block copolymer, styrene-butadiene rubber (SBR) and the like styrene-based random copolymer whose olefinic double bond has been hydrogenated.

[0150] In addition, as the styrene-based thermoplastic elastomer, a commercially available product can also be used.

[0151] The weight average molecular weight of the styrene-based thermoplastic elastomer is preferably in the range of 100,000 to 800,000, more preferably in the range of 300,000 to 500,000, and further preferably in the range of 500,000 to 3,000,000.

[0152] If the weight average molecular weight is set to the above range, it is easy to adjust the storage modulus and the tangent of the loss angle of the melt-softening layer to be in the desired range, and the melting or softening of the melt-softening layer by heating becomes easy.

[0153] Note that the weight average molecular weight of the styrene-based thermoplastic elastomer is measured in the same manner as the weight average molecular weight of the above-described acrylic polymer.

[0154] The styrene-based thermoplastic elastomer can be used alone or in combination with two or more. That is, the styrene-based thermoplastic elastomer can be one or two or more triblock copolymers, one or two or more diblock copolymers, or a mixture of a triblock copolymer and a diblock copolymer.

[0155] Among them, from the viewpoint of showing a moderate cohesive force from the melt-softening layer, having good adhesion at room temperature (0 to 40°C) before heating, and being able to easily melt or soften by heating, the styrene-based thermoplastic elastomer preferably contains at least a diblock copolymer.

[0156] The content of the diblock copolymer in the styrene thermoplastic elastomer is preferably in the range of 10 to 100% by mass, more preferably in the range of 10 to 90% by mass, and further preferably in the range of 15 to 80% by mass; and particularly preferably in the range of 20 to 75% by mass from the viewpoint of the balance between the adhesiveness at 20°C and the heat-based meltability.

[0157] The melt-softening layer is melted or softened by the heat generated from the heat-generating body, thereby making the adhesion in heating lower than the adhesion in the vicinity of room temperature (0 to 40°C).

[0158] The content ratio of the thermoplastic resin in the melt-softening layer is preferably in the range of 30 to 95% by mass, and more preferably in the range of 35 to 90% by mass, with respect to the total amount of the melt-softening layer. If the content of the thermoplastic resin in the melt-softening layer is in the above range, it is advantageous from the viewpoint of controlling the coatability and the melt-softening temperature of the melt-softening layer.

[0159] <Optional Components> The melt-softening layer can further contain a filler for the purpose of improving the initial adhesion by imparting softness and improving the heat-accumulating effect of the melt-softening layer by reducing the thermal conductivity. As the filler, there are organic fillers and inorganic fillers, which can be solid or hollow.

[0160] As the resin constituting the organic filler, for example, there are resins containing structural units derived from acrylonitrile, chlorovinyl, vinylidene chloride, styrene, vinyl acetate, ethylene, (meth)acrylate, and the like.

[0161] For example, there are acrylonitrile-based copolymers, vinylidene chloride-based copolymers, acrylic acid-based copolymers, styrene-based copolymers, polyethylene-based copolymers, and the like. The surface of the organic filler can be surface-treated with organic surface treatment agents such as fatty acids and fatty acid esters; inorganic surface treatment agents such as calcium carbonate, barium sulfate, talc, titanium oxide, titanium, clay, and silica.

[0162] As the inorganic substance constituting the inorganic filler, for example, there are metal oxide-based ceramics such as alumina, silica, silica alumina, zirconia, and magnesium oxide; non-oxide-based ceramics such as silicon carbide, boron carbide, carbon nitride, aluminum nitride, silicon nitride, and boron nitride; and glass, calcium carbonate, volcanic ash (shirasu), fly ash, and the like.

[0163] The inorganic filler can be subjected to surface treatment such as hydrophobization with a silane coupling agent, a fluorine-based compound, and the like.

[0164] The filler can be used alone or in combination of two or more.

[0165] In the case where the melt-softening layer further contains a filler, the amount thereof is preferably in the range of 5 to 80% by volume, more preferably in the range of 10 to 65% by volume, with respect to the total volume of the melt-softening layer. In addition, the content of the organic filler or the inorganic filler is preferably in the range of 0.01 to 30% by mass, more preferably in the range of 0.02 to 20% by mass, with respect to the total mass of the melt-softening layer.

[0166] The melt-softening layer can further contain, within a range not impairing the effects of the present application, an antioxidant, an anti-aging agent, a coloring agent such as a pigment or a dye, a thickening agent, a leveling agent, a film-forming aid, an infrared absorber, an ultraviolet absorber, a water repellent, or other additives as needed.

[0167] The melt-softening layer can further contain a tackifying resin for the purpose of adjusting the adhesiveness thereof. The tackifying resin is the same as the tackifying resin described in the item of the adhesive layer.

[0168] The tackifying resin can be contained singly or in two or more kinds. In the case where the melt-softening layer contains a tackifying resin, it is preferable to contain a tackifying resin having a mass reduction rate of 5% or less when raised from 25°C to 200°C at a temperature increase of 10°C / minute under a nitrogen atmosphere.

[0169] In the case where the melt-softening layer contains a tackifying resin, the amount of the tackifying resin is preferably in the range of 1 to 150 parts by mass, more preferably in the range of 10 to 150 parts by mass, with respect to 100 parts by mass of the thermoplastic resin constituting the melt-softening layer, from the viewpoint of allowing the adhesiveness thereof to be good at around room temperature (0 to 40°C) and allowing heat durability to be exerted.

[0170] In the case where the melt-softening layer contains a tackifying resin, the total content of the thermoplastic resin and the tackifying resin constituting the melt-softening layer is preferably in the range of 70 to 99.9% by mass, more preferably in the range of 80 to 99.8% by mass, with respect to the total mass of all the components constituting the melt-softening layer, that is, the thermoplastic resin and the tackifying resin, and a crosslinking agent, a filler, and other additives, if any.

[0171] The melt-softening layer can further contain a crosslinking agent for the purpose of improving the cohesive force. The crosslinking agent is the same as the crosslinking agent described in the item of the adhesive layer.

[0172] <Physical properties of the melt-softening layer> The melting point of the melt-softening layer is preferably lower than the melting point of the adhesive layer, specifically preferably in the range of 80 to 200°C, more preferably in the range of 90 to 180°C, further preferably in the range of 100 to 160°C.

[0173] Herein, the "melting point of the melt-softening layer" refers to the melting point of the composition containing the thermoplastic resin that constitutes the melt-softening layer.

[0174] Hereinafter in the specification, the "composition containing a thermoplastic resin that constitutes the melt-softening layer" will also be simply referred to as "melt-softening resin composition".

[0175] In other words, the melt-softening resin composition is a composition formed from the thermoplastic resin that constitutes the melt-softening layer, a tackifying resin, a crosslinking agent, other additives, and the like, which are further contained as necessary. The "melting point of the melt-softening layer" refers to the melting point of this melt-softening resin composition.

[0176] If the melting point of the melt-softening layer is within the above range, the adhesive tape of the present application is able to exert a high adhesive force before heating. Also, when thermally disassembling an article having a constitution bonded by the adhesive tape of the present application, even if the amount of heating due to heat generated by a heat-generating body is small, the melting or softening of the melt-softening layer is able to occur stably and preferentially, and disassembly is able to be performed easily and in a short time.

[0177] Note that the "melting point of the melt-softening layer" is the temperature of the endothermic peak accompanying the melting of the melt-softening resin composition, as measured using differential scanning calorimetry (DSC).

[0178] From the viewpoint of fixing the adherends to each other well in a state at around room temperature (0 to 40°C), the storage modulus G' of the melt-softening layer (i.e., the melt-softening resin composition) at 23°C is preferably 1.0 x 104Pa or more. 23 More preferably, it is 1.0 x 105Pa or more. 3 Further more preferably, it is 1.0 x 106Pa or more. 9 Still more preferably, it is 1.0 x 107Pa or more. 3 In particular, it is 5.0 x 107Pa or more. 7 More particularly, it is 5.0 x 108Pa or more. 3 Further more particularly, it is 5.0 x 109Pa or more. 7 Still more particularly, it is 5.0 x 1010Pa or more. 3 In particular, it is 5.0 x 107Pa or more. 3 More particularly, it is 5.0 x 108Pa or more. 6 Further more particularly, it is 5.0 x 109Pa or more.

[0179] From the viewpoint of easily separating the adherends from each other by heating, the storage modulus G' of the melt-softening layer at 120°C is preferably 1.0 x 104Pa or less. 120 More preferably, it is 1.0 x 105Pa or less. 0 Further more preferably, it is 1.0 x 106Pa or less. 6 Still more preferably, it is 1.0 x 107Pa or less. 3 In particular, it is 5.0 x 107Pa or less. 6 More particularly, it is 5.0 x 108Pa or less. 3 Further more particularly, it is 5.0 x 109Pa or less.3 Pa ~ 1.0 x 10 6 Pa, and further preferably 5.0 x 10 3 Pa ~ 5.0 x 10 5 Pa. If the storage modulus G 120 is in the above range, the molten softening layer can be melted or softened in a short time by heating to peel off.

[0180] Further, the tan δ of the molten softening layer in a temperature range of 80°C or higher is preferably 0.8 or higher, and more preferably 1 or higher. δ

[0181] As one of the preferable modes of the molten softening layer, the temperature at which the tan δ of the molten softening layer reaches 0.8 or higher is lower than the temperature at which the tan δ of the adhesive layer (adhesive layer composition) reaches 0.8 or higher.

[0182] In detail, the temperature range at which the tan δ of the molten softening layer reaches 0.8 or higher is, for example, preferably 80°C or higher, more preferably 80°C or higher and 200°C or lower, further preferably 100°C or higher and 160°C or lower, and further more preferably 100°C or higher and 130°C or lower.

[0183] More specifically, the temperature at which the tan δ of the molten softening layer reaches 0.8 or higher is preferably 80°C or higher, more preferably 80°C or higher and 200°C or lower, and further preferably 100°C or higher and 160°C or lower.

[0184] Further, the temperature at which the tan δ of the molten softening layer reaches 1 or higher is preferably 80°C or higher, more preferably 80°C or higher and 200°C or lower, and further preferably 100°C or higher and 180°C or lower.

[0185] The temperature difference between the temperature at which the tan δ of the molten softening layer reaches 0.8 or higher (and more preferably the temperature at which the tan δ reaches 1 or higher) and the temperature at which the tan δ of the adhesive layer (adhesive layer composition) reaches 0.8 or higher (and more preferably the temperature at which the tan δ reaches 1 or higher) is, for example, 10°C or higher, preferably 25°C or higher, further preferably 30°C or higher, and more preferably 50°C or higher, as long as it is a temperature difference that enables the molten softening layer to be preferentially melted or softened by receiving heat from the heat generating body.

[0186] ​In the adhesive tape of the present application, if the melt-softening layer has such properties, when the adhesive layer and the melt-softening layer receive the same heat from the heat-generating body, melting and / or softening of the melt-softening layer easily occurs preferentially.

[0187] When the melt-softening layer reaches the desired peeling temperature range described later by heat generated by the heat-generating body, plastic deformation easily occurs due to melting or softening, and peeling can occur within the layer of the melt-softening layer, or at the interface of the layer adjacent to the melt-softening layer, the adherend, by cohesive failure within the melt-softening layer.

[0188] That is, when an article having a configuration bonded by the adhesive tape of the present application is subjected to thermal peeling, melting or softening of the melt-softening layer can stably and preferentially occur, and peeling can be easily performed in a short time.

[0189] Note that, from the viewpoint of good adhesiveness before peeling, the melt-softening layer has a tan δ Preferably, it is 0.1 to 0.8, and more preferably, it is 0.2 to 0.6.

[0190] Note that the storage modulus G and tan δ It is measured by dynamic viscoelasticity measurement. For example, a test piece of the melt-softening resin composition having a dry thickness of about 2 mm is prepared, and using a viscoelasticity tester (ARES-G2, manufactured by TA Instruments Japan, Inc.), the storage modulus G' and the loss modulus (G'') at each temperature are measured under the conditions of a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a temperature increase rate of 2°C / minute. The tan δ It can be calculated from the formula [tan δ = G'' / G'].

[0191] The storage modulus G 23 of the melt-softening layer, the storage modulus G 120 , and the tan μ The storage modulus G , the storage modulus G

[0192] , and the melting point can be adjusted by the type and combination of the thermoplastic resin, the compounding amount of the tackifying resin added as needed, the addition amount of the crosslinking agent added as needed, and the like. μ From the viewpoints of coatability, adhesion retention to the adherend, and peeling properties, the thickness of the melt-softening layer can be set to 500 μ μm or less, preferably in the range of 10 to 200 Figure 1 μm, and more preferably in the range of 20 to 150 μm or less, preferably in the range of 10 to 200

[0193] The adhesive tape of the present application has at least one fusion-softened layer adjoining the heat-generating body, and can also have a fusion-softened layer c1 adjoining one side of the layered heat-generating body and a fusion-softened layer c2 adjoining the other side of the heat-generating body. The specific layer constitution of the adhesive tape having two fusion-softened layers will be described later.

[0194] [Layer structure of adhesive tape] The first mode of the adhesive tape of the present application, as shown in Figure 2 and Figure 3 , the adhesive tape 10 can be in the form of a laminate having a planar heat-generating body b, an adhesive layer a disposed on one side of the planar heat-generating body b, and a fusion-softened layer c disposed on the other side of the planar heat-generating body b, and laminated in the order of adhesive layer a / heat-generating body b / fusion-softened layer c.

[0195] By the heat generated by the heat-generating body b, the fusion-softened layer c adjoining the heat-generating body b is fused or softened, the adhesive force is reduced, and peeling becomes possible.

[0196] The planar heat-generating body b is preferably provided with one pair of protruding portions e (see Figure 4 and Figure 4 ) protruding from the outer periphery of the adhesive layer a and the fusion-softened layer c in a plan view. The protruding portions e can be two or more, and there is no particular limitation on the position in the heat-generating body, which can be appropriately selected according to the purpose. Two protruding portions e can be located on the same side of the outer periphery of the adhesive layer a and the fusion-softened layer c (see Figure 3 (1) to (3)), or can be located on different sides (see Figure 4 , Figure 4 (4) to (6)).

[0197] The protruding portions e are preferably located on opposite sides of the outer periphery of the adhesive layer a and the fusion-softened layer c (see Figure 4 (4) to (6)), and are preferably located on substantially diagonal lines of the outer periphery of the adhesive layer a and the fusion-softened layer c (see Figure 4 (2) to (7)). In the case where the protruding portions e are located on the same side of the outer periphery of the adhesive layer a and the fusion-softened layer c, the heat-generating body b is preferably in the shape of aコ (ko) or a zigzag shape or the like in a plan view (see Figure 4 (1) to (4) and (8)), and can also be located on a close portion of the same side (see Figure 4 (3) and (8)), as long as the heat-generating body b can uniformly heat the adhesive layer a and the fusion-softened layer c in the plane.

[0198] Thus, the current can be made to flow through the entire area of the planar heat-generating body b, and the heat-generating efficiency can be further improved.

[0199] The extensions e can also be more than 3 (see Figure 5 (9) and the desired pair (2) can be appropriately selected and the heating element energized. The pair of extensions e of the heating element b function as a pair of terminals for electrical connection to a power source in the method of detaching the article described later and the heating element b can be easily energized.

[0200] From the viewpoint of easy contact with the power source and heat source, the length of the extensions is preferably 1 to 50 mm and more preferably 2 to 25 mm. The extensions can be bent in a direction different from the direction of the surface of the adhesive tape.

[0201] For example, the extensions can be bent in a direction perpendicular to the direction of the surface of the adhesive tape and stored when the adherends are adhered to each other and the extensions can be bent again in the surface direction to contact the extensions with the power source and heat source when the adherends are to be detached.

[0202] In addition, as a second aspect of the adhesive tape of the present application, as shown in μ , the adhesive tape 20 can be a laminate in which the adhesive layer al / heating element b / melt-softening layer c / adhesive layer a2 are sequentially stacked.

[0203] Alternatively, the adhesive tape 20 can be a laminate in which the adhesive layer al / melt-softening layer cl / heating element b / melt-softening layer c2 are sequentially stacked and in this case, the adhesive layer a2 can be further provided on the side of the melt-softening layer c2 opposite the heating element b.

[0204] That is, as a second aspect of the adhesive tape of the present application, there can be mentioned a laminate having a heating element b, an adhesive layer al provided on one face of the heating element b, a melt-softening layer c provided on the other face of the heating element b, and an adhesive layer a2 provided on a face of the melt-softening layer c different from the adjoining face of the heating element b.

[0205] In addition, as another example of the second aspect, there can be mentioned a laminate having a heating element b, melt-softening layers cl and c2 provided on both faces of the heating element b, an adhesive layer al provided on a face of the melt-softening layer cl different from the adjoining face of the heating element b, and an adhesive layer a2 provided on a face of the melt-softening layer c2 different from the adjoining face of the heating element b.

[0206] By the heat generated by the heating element b, the melt-softening layer cl or c2 adjoining the heating element b melts or softens, the adhesive force decreases and peeling becomes possible. The adhesive tape of the present application of the second aspect in which the adhesive layer is further provided on the face (opposite face) of the melt-softening layer different from the adjoining face of the heating element can increase the initial adhesive force and the rate of decrease in the adhesive force caused by heating becomes large.

[0207] In the top view, the preferably planar heating element b has a pair of protrusions extending from the outer periphery of the adhesive layers a1 and 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 of the first embodiment.

[0208] The adhesive tape of the present invention may have a release layer (also called a release sheet or release liner). Examples of release layers include: cellophane; kraft paper; clay-coated paper; paper laminated with a film such as polyethylene; paper coated with resins such as polyvinyl alcohol or acrylate copolymers; and synthetic resin films such as polyester or polypropylene coated with fluoropolymers or silicone resins. The release layer may be present on one side or on both sides of the adhesive tape of the present invention.

[0209] In the adhesive tape of the present invention, as long as the outermost layer (excluding the release layer) arranged opposite each other in the thickness direction has an adhesive surface that can adhere to the object being adhered, in addition to the adhesive layer, the heating element, and the melt softening layer, there may also be other layers such as an insulating layer, a heat insulation layer (e.g., a foamed resin layer, a hollow layer, or a layer containing hollow particles), or other functional layers with insulating, heat insulation, or heat insulation properties.

[0210] In the first embodiment of the adhesive tape of the present invention, the adhesive layer a and the melt-softening layer c can be the bonding surface of the adhered object, and in the second embodiment, the adhesive layer a1 and the adhesive layer a2 can be the bonding surface of the adhered object.

[0211] The adhesive tape of the present invention can have the following exemplary configurations, but is not limited to these. In the following layer configurations, " / " indicates a layer interface, for example, in "layer A / layer B", layer A and layer B are adjacent, i.e., directly connected. • Release layer / adhesive layer a / heating element b / melted softening layer c • Adhesive layer a / heating element b / melted softening layer c / release layer • Release layer / adhesive layer a / heating element b / melted softening layer c / release layer • Adhesive layer a / functional layer / heating element b / melted softening layer c / release layer • Release layer / adhesive layer a / functional layer / heating element b / melted softening layer c / release layer • Release layer / adhesive layer a / heating element b / melted softening layer c / adhesive layer a • Adhesive layer a / heating element b / melted softening layer c / adhesive layer a / Peel-off layer / Adhesive layer a / Heating element b / Melt softening layer c / Adhesive layer a / Peel-off layer / Adhesive layer a / Heating element b / Melt softening layer c / Functional layer / Adhesive layer a / Peel-off layer / Adhesive layer a / Functional layer / Heating element b / Melt softening layer c / Adhesive layer a / Peel-off layer / Adhesive layer a / Functional layer / Heating element b / Melt softening layer c / Functional layer / Adhesive layer a / Peel-off layer / Adhesive layer a / Melt softening layer c / Heating element b / Melt softening layer c / Peel-off layer The thickness of the adhesive tape as a whole according to the present application is preferably 50 μ m ~ 2000 μ m, more preferably 50 μ m ~ 1000 μ m, further preferably 50 μ m ~ 800 Figure 6 m. In this case, when the adherends are joined to each other, in addition to being able to impart a cushioning property (flexibility) and the like, it is also possible to further improve the operability of the adhesive tape in terms of mechanical strength and processability and the like.

[0212] [Use of the adhesive tape] The adhesive tape according to the present application functions as a surface (adhesive surface) having adhesiveness on both sides of the removal of the release layer, and thus it is possible to adhere the adherends to each of the both sides of the adhesive tape, and it is possible to be suitably used for the joining of the adherends to each other.

[0213] The adhesive tape according to the present application can be peeled by heating, preferably resistance heating, and thus it is particularly suitable for use as a resistance heating (electricity heating) peeling tape.

[0214] The adhesive tape according to the present application can be suitably used, for example, for the adhesion of an adherend that is a rigid body to an adherend, and the separation of the adherends to each other.

[0215] The adhesive tape according to the present application can be easily peeled by heating, and thus it can be used for applications in which the adhesive tape needs to be peeled when separating components for the purpose of recycling or reusing. For example, it can be suitably used as an adhesive tape for fixing components between various products in industrial applications such as electronic devices, automobiles, building materials, OA, and home electric appliances, and it can improve the work efficiency when separating the components, peeling the labels, and the like.

[0216] [Manufacturing method of the adhesive tape] The manufacturing method of the adhesive tape according to the present application is not particularly limited. For example, the adhesive tape according to the present application of the above-described first mode can be manufactured by a method in which a composition containing components constituting the adhesive layer and a solvent is applied to a release sheet and dried to form the adhesive layer, a composition containing components constituting the melt-softening layer and a solvent is applied to another release sheet and dried to form the melt-softening layer, and they are sequentially adhered to each surface of a planar heat generating body.

[0217] Here, the release sheet on the surface side of the melt-softening layer of the obtained adhesive tape is peeled, and the adhesive layer formed on the release sheet is further adhered to the exposed surface of the melt-softening layer, whereby the adhesive tape according to the present application of the above-described second mode can be manufactured.

[0218] Alternatively, the adhesive layer formed on the release sheet is attached to one side of the planar heat generating body, and a composition containing the components constituting the fusion softening layer and a solvent is applied to the other side of the planar heat generating body and dried to form the fusion softening layer, whereby the adhesive tape of the first aspect of the present application can be produced.

[0219] Further, by further attaching the adhesive layer formed on the release sheet to the surface of the fusion softening layer of the obtained adhesive tape, the adhesive tape of the second aspect of the present application can be produced.

[0220] Further, the composition containing the components constituting the adhesive layer and the composition containing the components constituting the fusion softening layer can be molded by extrusion molding, press molding, injection molding, or the like.

[0221] The solvent is not particularly limited, and examples thereof include organic solvents such as toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, and hexane; water; and aqueous solvents in which water is the main component. Note that the solvent can remain in the adhesive layer and the fusion softening layer of the obtained adhesive tape, but it is generally preferable that the adhesive layer and the fusion softening layer be free of the solvent.

[0222] 2. Article The present application also provides an article including at least two adherends and the adhesive tape of the present application between the two adherends, the two adherends being bonded via the adhesive tape.

[0223] The adherend can be rigid or flexible like a film. The material and shape of the adherend are not particularly limited, and examples thereof include a plate-shaped adherend including resin, glass, or metal, a case and a cover, and a member having any of them on the adhered surface.

[0224] The two adherends bonded via the adhesive tape can be the same as or different from each other. As the bonding method of the adherend, a method in which the adherend is attached to each surface of the adhesive tape of the present application having adhesion can be exemplified.

[0225] The article is not particularly limited, and is preferably an electronic device, a component built into an electronic device, or the like from the viewpoint of effectively utilizing the effects of the adhesive tape of the present application.

[0226] The article of the present application preferably has a pair of protrusions of the heat generating body constituting the adhesive tape protruding from the outer periphery of the adherend in a plan view.

[0227] For example, as illustrated in the schematic plan view of Figure 7 and the schematic cross-sectional view of Figure 6As shown in a schematic cross-sectional view, the article 100 of the present application is an article in which two adherends 50 are bonded via an adhesive tape 10, and the adhesive tape 10 is provided between the two adherends 50, and the adhesive tape 10 includes a laminated body of an adhesive layer a / a planar heat generating body b / a molten softening layer c, which are sequentially laminated.

[0228] In a plan view (Fig. 1 (b)), Figure 6 In the plan view, both ends of the planar heat generating body b in the long axis direction protrude from the outer periphery of the adhesive layer a and the molten softening layer c.

[0229] In the article disassembly method described later, the both ends of the protruding adhesive tape 10 can be used as a pair of terminals for electrical connection to a power source or end portions in contact with a heat source in the case where the heating means is either of resistance heating and heat conduction, and the heat generating body b of the adhesive tape 10 can be easily heated. In addition, as shown in Figure 5 the smaller the contact area of the adherend with the adhesive tape in the plan view, the higher the heat generating efficiency of the heat generating body, and the easier the opportunity to disassemble at the time of heating, and thus it is advantageous in terms of easy disassembly.

[0230] In addition, although not shown, the article of the present application can also be an article in which two adherends and an adhesive tape as shown in Figure 6 described above are included between the two adherends, and the two adherends are bonded via the adhesive tape.

[0231] In the plan view of the article, the adhesive tape can be attached to the entire region of the surface of the adherend on the adhesive tape side, that is, the adhered surface, or the adhesive tape can be attached to a part of the adhered surface of the adherend. Among them, as shown in Figure 8 it is preferable that the adhesive tape 10 is attached to a part of the adhered surface of the adherend 50.

[0232] In this case, the plan view shape of the adhesive tape 10 in the article can be a band shape or a line shape, or a pattern shape. If the contact area of the adherend with the adhesive tape is made small, when the adhesive tape is peeled from the adherend by resistance heating, the starting point of peeling between the adherend and the adhesive tape can be easily generated, and thus it is advantageous from the viewpoint of easy peeling.

[0233] In addition, in the plan view of the article of the present application, in the case where the adhesive tape is attached to the entire region of the surface of the adherend on the adhesive tape side, that is, the adhered surface, the plan view shape of the planar heat generating body in the adhesive tape can be the same shape as the plan view shape of the adhesive tape, or can be a band shape, a line shape, or a pattern shape.

[0234] 3. Article disassembly method In addition, the present application also provides an article disassembly method of the above-described article of the present application, in which the molten softening layer is melted or softened by heating of the heat generating body, and thereby the two adherends are separated.

[0235] The disassembly method of the present application preferably includes a process (separation process) of separating at least two adherends by melting or softening the melting-softening layer by heating of the heat-generating body, and can further include other processes as necessary.

[0236] The heating means and method of the heat-generating body are not particularly limited, and examples thereof include resistance heating, electromagnetic induction heating, infrared heating, microwave heating, and heat conduction. Among them, resistance heating is preferred.

[0237] In the case where the heating of the heat-generating body is resistance heating, the separation process is preferably a process of electrically connecting the heat-generating body to a power source, applying electric power from the power source to the heat-generating body, and melting or softening the melting-softening layer adjacent to the heat-generating body by resistance heating, thereby separating the two adherends.

[0238] The power source can be an external power source, or a driving power source of an article that is an electronic device or a component built in an electronic device. In the case where the article is an electronic device or a component built in an electronic device, and the power source is a driving power source of the electronic device, the separation process is preferably a process of electrically connecting the heat-generating body to the driving power source and a circuit of the electronic device, applying electric power from the driving power source to the heat-generating body, and melting or softening the melting-softening layer by resistance heating, thereby separating the two adherends.

[0239] The method of electrical connection can be any method of electrically connecting one pair of protruding portions of the heat-generating body, which protrude from the heat-generating body or the adhesive layer and the outer periphery of the melting-softening layer, to the power source using a publicly known means such as an alligator clip.

[0240] The circuit and the means of electrical connection are preferably formed of an electrically conductive material that exhibits a volume resistivity different from that of the material of the heat-generating body in the adhesive tape, and more preferably formed of an electrically conductive material having a lower volume resistivity than the heat-generating body. In this case, when the heat-generating body is electrically connected to the circuit and electric power is applied from the driving power source to the heat-generating body, excessive heating of the circuit and the means of electrical connection can be prevented, and at the same time, electric voltage can be efficiently applied to the heat-generating body, so that peeling can be performed in a short time, which is advantageous.

[0241] The method of applying electric power can be appropriately selected depending on the size of the adhesive tape of the present application or the type of the heat-generating body, and examples thereof include a method of applying electric voltage of 0.1 to 200 V until the melting-softening layer is melted or softened (for example, in the range of 0.5 seconds to 30 minutes). As μ A simple power source can be used as illustrated schematically.

[0242] By electrically connecting the heat-generating body of the adhesive tape of the present application to a power source and applying electric voltage to the heat-generating body to apply electric power thereto, the heat-generating body and its periphery can be heated by resistance heating. By the above heating, the melting-softening layer is melted or softened, the bonded state is released, and peeling becomes possible, and the adherends adhered become disassemblable.

[0243] The voltage applied to the heat generating body by the energization is preferably in the range of 0.1 V to 200 V, more preferably 0.5 V to 150 V, and further preferably 1.0 V to 100 V.

[0244] The adhesive tape of the present application causes melting or softening of the melting and softening layer in a short time even if the applied voltage is low, and thus, by setting the voltage applied in the separation process to the above range, the article can be detached in a short time without applying excessive voltage, and damage to the article due to heat can be prevented. In particular, by applying a voltage corresponding to the article such as a small electronic device or a household appliance, the article can be easily detached.

[0245] The current applied to the heat generating body is not particularly limited, and is preferably in the range of 0.01 A to 20 A, more preferably 0.03 A to 15 A, further preferably 0.05 A to 10 A, and particularly preferably 0.1 A to 5 A. Since the adhesive tape of the present application causes melting or softening of the melting and softening layer in a short time, if the current applied in the separation process is set to the above range, the current flowing in a general electronic device or a household appliance is allowed to flow, and the article can be detached in a short time, and damage to the article due to heat can be prevented. In particular, by applying a current corresponding to the article such as a small electronic device or a household appliance, the article can be easily detached.

[0246] In addition, even if the worker accidentally comes into contact with the energization portion during the detaching work, the adhesive tape of the present application can obtain sufficient heat generation with a low current to the extent that does not cause physical effects on the worker. Thus, the detaching method of the present application is excellent in work safety.

[0247] The application time is not particularly limited, and is preferably in the range of 0.5 seconds to 30 minutes, more preferably 0.5 seconds to 120 seconds, and further preferably 0.5 seconds to 30 seconds. If the application time is set to the above range, damage to the article due to heat does not occur, and the article can be easily detached in a short time.

[0248] In the case where the heating of the heat generating body is electromagnetic induction heating, the separation process is preferably a process of melting or softening the melting and softening layer by electromagnetic induction heating using an electromagnetic induction heating means, thereby separating the two adherends. The electromagnetic induction heating means is not particularly limited, and a publicly known electromagnetic induction heating device can be appropriately selected.

[0249] In the case where the heating of the heat generating body is either of infrared heating and microwave heating, the separation process is preferably a process of melting or softening the melting and softening layer by either of infrared heating using an infrared heating means and microwave heating using a microwave heating means, thereby separating the two adherends.

[0250] The infrared heating means and the microwave heating means are not particularly limited, and a publicly known infrared heating device and a microwave heating device can be appropriately selected.

[0251] In a case where the heating of the heat generating body is heat conduction, the separating step is preferably a step of bringing the heat generating body into contact with a heat generating source to melt or soften the molten and softened layer by heat conduction, thereby separating the two adherends. The heat generating source is not particularly limited, and a publicly known heater can be appropriately selected.

[0252] The method using heat conduction of the heat generating source can be appropriately selected depending on the size of the adhesive tape, the type of the heat generating body, and the like, and for example, a method of bringing it into contact until the molten and softened layer is melted or softened at a desired temperature can be cited.

[0253] The detaching temperature of the article is preferably in the range of 80°C to 160°C, more preferably in the range of 90°C to 150°C, and further preferably in the range of 100°C to 130°C. By making the detaching temperature in the above range, heat damage to the article and the adherend can be suppressed, and detaching can be made easy. In particular, in a case where the heating of the adhesive tape is resistance heating (electrical resistance heating), by directly generating heat inside the tape, detaching can be made before heat is transferred to the article and the adherend.

[0254] The detaching temperature of the article can be measured by using a temperature sensor using a thermocouple as the temperature of the heat generating body of the adhesive tape of the present application (the achieved temperature of the heat generating body at the time of detaching).

[0255] The above describes one embodiment of the adhesive tape, the article, and the detaching method of the article of the present application, but the present application is not limited to the configuration of the above embodiment. For example, the adhesive tape of the present application can be additionally provided with any other configuration in the configuration of the above embodiment, or can be replaced with any configuration that produces the same effect.

[0256] Example Hereinafter, the present application will be specifically described by examples. However, the present application is not limited to the following examples. The materials used in the present examples and the like are shown below.

[0257] <Heat generating body> Heat generating body 1: metal fiber sheet In a case where the average fiber diameter is 1 μ m to 50 μ m, and the average fiber length is 100 μ m to 20 mm, the binder (coagulant of the organic system) is mixed in a manner such that the weight per unit area is 50 g / m 2 The metal fiber (stainless steel fiber) sheet is obtained by using a papermaking device to perform sheeting and firing after mixing the binder (coagulant of the organic system) in a manner such that the weight per unit area is 50 g / m μm, volume resistivity at 20°C: 1600 μ Ω-cm.

[0258] Heating element 2: graphite sheet Carbon fibers (average fiber length 100 μ m ~ 20 mm) or graphite (average particle diameter 1 μ m ~ 100 μ m) were sheeted, fired, and a graphite sheet was obtained. The thickness was 50 μ m, and the volume resistivity at 20°C was 5000 μ Ω-cm.

[0259] Heating element 3: graphite sheet impregnated with a cured phenol resin Carbon fibers (average fiber length 100 μ m ~ 20 mm) or graphite (average particle diameter 1 μ m ~ 100 μ m) were sheeted, and then impregnated with a cured phenol resin, and a graphite sheet was obtained by firing by hot pressing. The thickness was 90 μ m, and the volume resistivity at 20°C was 13700 μ Ω-cm.

[0260] Heating element 4: nickel-chromium alloy foil "Nickel-chromium NCH1-H" [trade name, manufactured by Takine Metal Foil Kogyo Co., Ltd., thickness 10 μ m. The volume resistivity at 20°C was 108 μ Ω-cm (catalog value), 105 μ Ω-cm (measured value) <Peeling layer> Release liner: polyethylene terephthalate film with a thickness of 75 δ m, which had been subjected to peeling treatment on one side <Materials constituting the melt-softening layer (melt-softening resin composition) [Preparation Example 1] A styrene-isoprene block copolymer composition (mixture of styrene-isoprene diblock copolymer and styrene-isoprene triblock copolymer; constitutional unit from styrene 24 mass%) 100 mass parts, Quintone G115 (C5 / C9 petroleum resin manufactured by ZEON Corporation, softening point 115°C) 40 mass parts, Pensel D-160 (polymerized rosin ester resin manufactured by Arakawa Chemical Industries, Ltd., softening point 15-150°C) 30 mass parts, Nisshin polybutene HV-50 (polybutene manufactured by JX Nippon Oil & Energy Corporation, flow point -12.5°C) 5 mass parts, and an anti-aging agent (tetra-[methylene-3-(3'5'-di-t-butyl-4-hydroxyphenyl)propionate]methane) 1 mass part were mixed, dissolved in toluene 100 mass parts as a solvent, and thus a resin composition 1 was obtained.

[0261] The obtained resin composition 1 was applied to a release liner in a manner such that the thickness after drying became about 2 mm, and a layer 1 was produced; using a viscoelastic tester (ARES-G2, manufactured by TA Instrument Japan Corporation), the storage modulus G' and the loss modulus (G'') were measured under conditions of a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a temperature increase rate of 2°C / minute. In addition, tan δ was measured at a frequency of 1 Hz. δ was calculated by the formula [tan

[0262] The melting point of the resin composition 1 was 140°C, the storage modulus G 23 at 23°C was 2.5 x 10 5 Pa, the storage modulus G 120 at 120°C was 5.0 x 10 4 Pa, and the temperature at which tan δ reached 0.8 was 125°C (tan δ reached 0.8 or more was 125°C or more.

[0263] <Composition of Adhesive Layer> [Preparation Example 2] Into a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, n-butyl acrylate 79.9 mass parts, 2-ethylhexyl acrylate 6 mass parts, cyclohexyl acrylate 10 mass parts, acrylic acid 4 mass parts, 4-hydroxybutyl acrylate 0.1 mass parts, and ethyl acetate 200 mass parts were put, and a mixture was obtained by nitrogen bubbling at 23°C for 1 hour with stirring.

[0264] Next, 2,2'-azobis(2-methylbutyronitrile) solution 2 parts by mass (1.0% by mass of solid content) previously dissolved in ethyl acetate was added to the mixture, and after stirring for 4 hours at 72°C and stirring for 5 hours at 75°C, the resulting mixture was diluted with ethyl acetate and filtered with a 200-mesh metal screen, thereby obtaining an acrylic copolymer solution having a weight average molecular weight of 1,060,000 and an average number of carbon atoms of the saturated hydrocarbon group possessed by the alkyl acrylate monomer of 4.4 (26% by mass of solid content).

[0265] To 100 parts by mass of the resulting acrylic copolymer solution, 1.0 parts by mass of an adduct of toluene diisocyanate and trimethylolpropane ("BURNOCK D-40" manufactured by DIC Corporation, isocyanate-based crosslinking agent, 40% by mass of solid content, hereinafter referred to as "D-40") was added as a crosslinking agent, thereby obtaining Composition 2.

[0266] Composition 2 was applied to the release-treated surface of a release liner in a manner such that the dried thickness became about 2 mm, and Layer 2 was produced; the storage modulus G' and loss modulus (G'') were measured using a viscoelastic tester (ARES-G2, manufactured by TA Instrument Japan Corporation) under conditions of a frequency of 1 Hz, a temperature range of -40°C to 200°C, and a temperature increase rate of 2°C / minute. In addition, tan δ was measured at a frequency of 1 Hz. δ was calculated from the formula [tan

[0267] Composition 2 had a melting point of 150°C or higher, a storage modulus G 23 at 23°C of 7.5 x 10 4 Pa, a storage modulus G 120 at 120°C of 5.5 x 10 4 Pa, and a temperature at which tan δ reached 0.8 of a temperature higher than 150°C (tan δ reached 0.8 or more at a temperature higher than 150°C. In addition, the maximum value of tan μ in the temperature range of 100°C to 150°C was 0.4.

[0268] 1. Production Examples of Adhesive Tape and Articles [Example 1] <Production of Adhesive Tape> Resin Composition 1 was applied to the release-treated surface of a release liner in a manner such that the dried thickness became 80 μ m, and dried at 90°C for 5 minutes, thereby obtaining a molten softening layer c1 (thermal conductivity 0.16 W / m-K).

[0269] On the other hand, the thickness of the other release liner after drying is 50. Figure 9 The composition 2 is coated in the manner of m and dried at 90°C for 3 minutes to form an adhesive layer (thermal conductivity 0.20 W / m·K).

[0270] It should be noted that the thermal conductivity of the melt-softened layer and the adhesive layer was measured using a rapid thermal conductivity meter (“QTM-710” manufactured by Kyoto Electronics Industry Co., Ltd.).

[0271] A molten softened layer c1, cut to a length of 50 mm and of arbitrary width, is bonded to a heating element 1, 100 mm in length, using a hand roller. The heating element 1 is positioned such that each end extends 25 mm beyond its length. Similarly, an adhesive layer, cut to a length of 50 mm and of arbitrary width, is bonded to the opposite side of the heating element 1, which is bonded to the molten softened layer c1. This is then laminated from the upper surface of the release liner using a roller with a linear pressure of 5 kg / cm, and cured at 40°C for 48 hours. This produces a heating element 1 with each end extending 25 mm beyond the outer periphery of the molten softened layer c1 and the adhesive layer along its length, and a total thickness excluding the release liner of 180 mm. Figure 10 m, except for the release liner, constitutes a laminate consisting of an adhesive layer a1, a heating element 1, and a melt softening layer c1 stacked in sequence.

[0272] The resulting laminate is cut with a width of 2 mm to obtain adhesive tape (T-1), wherein the melt-softened layer c1 and adhesive layer a1 are 2 mm wide × 50 mm long, the heating element 1 is 2 mm × 100 mm long, and the heating element 1 has a pair of protrusions extending from the outer periphery of the melt-softened layer c1 and adhesive layer a1. A schematic top view of adhesive tape (T-1) is shown below. Figures 11-13 The schematic cross-section is shown in Figures 11-13 .

[0273] <Item Crafting> For the adhesive tape of Example 1 ( Figures 11-13 (Referring to Figure 10), peel off the release liner from the side of the melted softened layer c1, and attach it to the substrate 50a (glass, 40mm wide × 50mm long × 10mm thick) with the adhesive tape (effective portion) extending 50mm across the center of the substrate 50a in the width direction. (Refer to Figure 10). Figures 11-13 Next, peel off the release liner on the adhesive layer a1 side to hold the adhesive tape 10 in the shape of the object to be bonded 50b (glass, 30mm wide × 100mm long × 2.8mm thick) (refer to...). Figure 11 Paste at 20 N / cm 2The resulting adhered article was left to stand for 24 hours or more in an atmosphere of 23°C and 50% RH, whereby the article of Example 1 was obtained.

[0274] [Example 2] In Example 1, the heat-generating body 2 was used instead of the heat-generating body 1, and otherwise, by the same steps as in Example 1, the adhesive tape (T-2) and the article of Example 2 were produced.

[0275] [Example 3] In Example 1, the heat-generating body 3 was used instead of the heat-generating body 1, and otherwise, by the same steps as in Example 1, the adhesive tape (T-3) and the article of Example 3 were produced.

[0276] [Reference Example 1] In Example 1, the heat-generating body 4 was used instead of the heat-generating body 1, and otherwise, by the same steps as in Example 1, the adhesive tape (RT) and the article of the reference example were produced.

[0277] 2. Evaluation For the article obtained in each of the examples and the reference example, the push strength was measured in the following manner using the apparatus shown in Fig. 1. Figures 12-13

[0278] (1) Push strength before heating The article obtained in each of the examples and the reference example was used as a test piece, and in a press position of 23°C, a glass plate was pressed in the arrow direction at a speed of 10 mm / min using the probe 70 shown in Fig. 1, and the strength at the time of peeling of the adhesive tape [push strength (Gl)] was measured. Figures 12-13 ​ (2) Push strength after heating for 10 seconds The article obtained in each of the examples and the reference example was used as a test piece, and the protruding portion e of the heat-generating body in the adhesive tape 10 of each test piece was held with the crocodile clip 60, and a direct current stabilizing power supply (manufactured by Kikusui Electronics Corp., trade name "PAS160-1") was used to pass a current of 0.3 A. After 10 seconds from the start of the current passage, the glass plate was pressed in the arrow direction at a speed of 10 mm / min using the probe 70 shown in Fig. 1 while continuing the current passage, and the strength at the time of peeling of the adhesive tape [push strength (G2)] was measured. Note that the achieved temperature of the heat-generating body at the time of peeling with the current passage of 0.3 A (the peeling temperature of the article) was about 95°C.

[0279] ​ The temperature of the heat-generating body after the current passage was measured by a temperature sensor using a thermocouple.

[0280]

[0281] (3) Residual adhesive force ​​​​Using the pressing strength (G1) and the pressing strength (G2), the residual adhesive force was calculated using the following formula, and the detachability was evaluated according to the following criteria.

[0282] Residual adhesive force (%) = 100 x G2 / G1 [Evaluation criteria for detachability] O: Residual adhesive force less than 75% Δ: Residual adhesive force 75% or more and less than 90% X: Residual adhesive force 90% or more The results are summarized in Table 1.

[0283] [Table 1] The residual adhesive force after 0.3A current heating of the adhesive tape of each example was smaller than that of the reference example. That is, the article made using the adhesive tape of each example had a large adhesive force reduction rate relative to the initial adhesive force even in the case where a low current that does not affect the body of the worker was passed, and the detachability was excellent.

[0284] Industrial applicability The adhesive tape of the present application can be heated and peeled in a short time, can prevent thermal damage to the adherend, and the operation of heating and peeling is easy. Therefore, the adhesive tape of the present application can be suitably used as an adhesive tape that needs to be peeled when separating components for the purpose of recycling or recycling, for example, an adhesive tape that is used for fixing between components of various products in industrial uses such as electronic devices, automobiles, building materials, OA, home appliance industry, and the like, and can improve the work efficiency when separating between components, label peeling, and the like.

[0285] Explanation of reference numerals a, a1, a2: adhesive layer b: heat generating body c: melt-softening layer e: protrusion (of the heat generating body) 10, 20, 30: adhesive tape 50, 50a, 50b: adherend 100: article 60: crocodile clip 70: probe P: pressed position.

Claims

1. An adhesive tape, characterized by At least sequentially having an adhesive layer, a heating element, and a fusion softening layer adjacent to the heating element, the average thickness of the heating element is 2 μ m or more and 200 μ m or less, the heating element is a heating element obtained by bonding and sheeting an electrically conductive filler.

2. The adhesive tape according to claim 1, wherein The volumetric resistivity of the heat generating body at 20°C is 50 μ Ω·cm or more.

3. The adhesive tape according to claim 1, wherein The heat generating body is a heat generating body obtained by bonding and sheeting a fibrous or particulate conductive filler, and further impregnating a binder.

4. The adhesive tape according to claim 1, wherein The heat generating body is a heat generating body obtained by bonding and sheeting a fibrous or particulate conductive filler and an organic filler.

5. The adhesive tape according to claim 1, wherein The heat generating body is a heat generating body obtained by firing and sheeting a fibrous or particulate conductive filler.

6. The adhesive tape according to claim 1, wherein The conductive filler is selected from a metal, an alloy, and carbon.

7. The adhesive tape according to claim 1, wherein In a plan view, the heat generating body has one pair of protrusions protruding from the outer periphery of the adhesive layer and the melt-softening layer.

8. The adhesive tape according to claim 1, wherein The melt-softening layer has an adhesive layer on the side opposite to the side adjacent to the heat generating body.

9. The adhesive tape according to claim 1, wherein The melt-softening layer is capable of being peeled by heating.

10. The adhesive tape according to claim 1, wherein The heat generating body is an electrically conductive body that generates heat by electric conduction, and the adhesive tape is peeled by the heat generation of the electrically conductive body.

11. An article, characterized by, Comprising: at least two adherends; and the adhesive tape according to any one of claims 1 to 10 between the two adherends, The two adherends are adhered via the adhesive tape.

12. The article of claim 11, wherein, In a plan view, the heat generating body constituting the adhesive tape has one pair of protrusions protruding from the outer periphery of the adherend.

13. The method of claim 11, wherein the article is a package. The melt-softening layer is melted and / or softened by the heating of the heat generating body, thereby separating the two adherends.

14. The method of disassembly of an article according to claim 13, wherein, The heating of the heat generating body is resistance heating, the heat generating body is electrically connected to a power source, the heat generating body is electrically conducted from the power source, the melt-softening layer is melted and / or softened by resistance heating, thereby separating the two adherends. The heating of the heat generating body is resistance heating, the heat generating body is electrically connected to a power source, the heat generating body is electrically conducted from the power source, the melt-softening layer is melted and / or softened by resistance heating, thereby separating the two adherends.

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