Thermally decomposable sheet, thermally decomposable sheet with peeling liner, laminate, joined body, method for manufacturing joined body, and method for disassembling joined body

Abstract

To provide a thermally decomposable sheet which is excellent in handleability, adhesive force and thermal decomposition property, a thermally decomposable sheet with a peeling liner using the thermally decomposable sheet, a laminate, a joined body excellent in thermal decomposition property, a method for manufacturing a joined body, and a method for disassembling a joined body.SOLUTION: A thermally decomposable sheet includes a thermally decomposable layer, wherein the thermally decomposable layer contains a resin and an inorganic expansion agent, a content of the inorganic expansion agent relative to 100 pts.mass of the resin is 10 pts.mass or more, and adhesive force of the thermally decomposable sheet is 1.0 N / 20 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a thermally disintegrable sheet, a thermally disintegrable sheet with a release liner, a laminate, a bonded body, a method for producing a bonded body, and a method for dismantling a bonded body. [Background technology]

[0002] Adhesives are used to join members made of various materials such as resin, rubber, metal, glass, ceramics, and paper. In recent years, research has been conducted into easily dismantlable adhesives that have sufficient adhesive strength according to the intended use and the ability to reduce adhesive strength at any time to allow for easy peeling (dismantling). Demand for such easily dismantlable adhesives is increasing for applications such as the separate collection of bonding materials used to join components made of different materials, the repair and replacement of components, and improving productivity through temporary bonding in the manufacturing process.

[0003] As dismantling means, for example, methods using stimuli such as heating, voltage application, light irradiation, and immersion in chemical solutions are being considered. Dismantling means using heat include, for example, thermal decomposition of resins and additives contained in adhesives, and expansion of additives, and as expansion agents, resin microcapsules containing liquid low-boiling point hydrocarbons and inorganic expansion agents such as expanded graphite are used.

[0004] For example, Patent Document 1 describes a hot melt adhesive that uses a thermoplastic epoxy resin with a specific formulation and can be attached and fixed to an adherend at relatively low temperatures, and can be bonded by heating to 150°C or higher.It also has high shear adhesive strength and, because it is thermoplastic, can be made recyclable by reheating. Furthermore, Patent Document 2 describes an easily dismantled adhesive sheet having an adhesive layer containing an inorganic expanding agent and a resin, with the adhesive strength of the adhesive layer controlled within a specific range, which provides excellent adhesiveness and holding power, and also provides excellent adhesive strength for firmly adhering adherends, as well as dismantlability that allows the bonded body to be easily dismantled when desired. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-126942 [Patent Document 2] International Publication No. 2023 / 176800 Summary of the Invention [Problem to be solved by the invention]

[0006] However, since the hot melt adhesive described in Patent Document 1 has a high modulus of elasticity at 120°C, the dismantling properties of a bonded body using this hot melt adhesive are insufficient, resulting in poor workability. Furthermore, the easily dismantlable adhesive sheet described in Patent Document 2 is adhesive, which makes it difficult to adjust the attachment position when attaching the sheet to adherends, and is therefore poor in handleability.

[0007] The present invention has been made in view of the above-mentioned circumstances, and aims to provide a thermally disintegrable sheet having excellent adhesive strength and thermal disintegrability. It also aims to provide a thermally disintegrable sheet with release liner, a laminate, a bonded body having excellent thermal disintegrability, a method for manufacturing a bonded body, and a method for dismantling a bonded body, all of which use the thermally disintegrable sheet. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems, and as a result have found that a thermally disintegrable sheet having an elastic modulus controlled within a specific range at a specific temperature can provide a bonded article that is easy to handle, has excellent adhesive strength for strong bonding to adherends, and exhibits thermal disintegrability that allows easy disassembly at a desired temperature, thereby completing the present invention.

[0009] The means for solving the above problems are as follows. [1] A thermally disintegrable sheet having a thermally disintegrable layer, the thermally disintegratable layer contains a resin and an inorganic expanding agent, The content of the inorganic expanding agent relative to 100 parts by mass of the resin is 10 parts by mass or more, The adhesive strength of the thermally disintegratable sheet is 1.0 N / 20 mm or less. Thermally decomposable sheet. [2] The thermally disintegratable layer is Elastic modulus E' at 25°C 25 is 10 5 Pa or more 10 10 Pa or less, Elastic modulus E' at 120°C 120 is 10 4 Pa or more 10 8 Pa or less, Elastic modulus E' at 250℃ 250 is 10 5 Pa or less, The thermally disintegrable sheet according to [1]. [3] The thermally disintegrable sheet according to [1], which has an expansion ratio in the thickness direction of 2.0 times or more after heating at 250°C for 10 minutes. [4] The thermally disintegratable sheet according to [1], wherein the inorganic expanding agent is expanded graphite or a silicate. [5] The thermally disintegrable sheet according to [1], wherein the thermally disintegrable layer further contains a filler. [6] The thermally disintegrable sheet according to [5], wherein the resin comprises at least one selected from polyamide resin, acrylic rubber, and epoxy resin. [7] The thermally disintegrable sheet according to [5], wherein the resin comprises an epoxy-modified resin. [8] The thermally disintegrable sheet according to [1], further comprising a resin layer. [9] A thermally disintegrable sheet with a release liner, comprising the thermally disintegrable sheet according to [1] and a release sheet.

[10] A laminate in which the thermally disintegrable sheet according to any one of [1] to [8] is laminated on a resin material.

[11] A bonded body obtained by bonding the thermally disintegrable sheet according to any one of [1] to [8] and a resin material.

[12] the resin material is a first member, The joined body according to

[11] , wherein the first member and the second member are joined by the thermally disintegrable sheet.

[13] The bonded body according to

[12] , wherein the resin material includes a thermosetting resin.

[14] A method for producing a bonded body using the thermally disintegrable sheet according to any one of [1] to [8].

[15] a lamination step of laminating the thermally disintegratable sheet and a resin material; a fusion step of fusing the thermally disintegratable layer and the resin material, A method for producing the bonded body according to

[13] .

[16] a lamination step of laminating the thermally disintegrable sheet and a substrate; an impregnation step of impregnating the substrate with a resin composition; a curing step of curing the resin composition to form a resin material; Equipped with A method for producing the bonded body according to

[13] .

[17]

[12] A method for dismantling the bonded body according to

[11] , comprising the step of heating at least a part of the bonded body to destroy the thermally disintegrable layer. [Effects of the Invention]

[0010] According to the present invention, a thermally disintegrable sheet having excellent handling properties, adhesive strength, and thermal disintegrability can be obtained. Furthermore, a bonded body bonded with the thermally disintegrable sheet of the present invention has excellent thermal disintegrability, being easily disintegrated at a desired temperature. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a thermally disintegrable sheet according to an embodiment of the present invention. [Figure 2]FIG. 2 is a schematic cross-sectional view showing a thermally disintegrable sheet according to another embodiment of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view showing a bonded body bonded by a thermally disintegrable sheet according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view for explaining a joined body used for evaluation of dismantling property and expansion ratio in the examples. [Figure 5] FIG. 6 is a schematic cross-sectional view for explaining the bonded body of the example. [Figure 6] FIG. 6 is a schematic cross-sectional view for explaining a joined body used for evaluation of dismantling ease and expansion ratio in the examples. [Figure 7] FIG. 7 is a schematic cross-sectional view for explaining a joined body used for evaluation of dismantling ease and expansion ratio in the examples. [Figure 8] FIG. 8 is a schematic cross-sectional view for explaining the bonded body of Comparative Example 5. As shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to the following embodiments and can be modified as desired without departing from the spirit of the present invention. Furthermore, the symbol "to" indicating a numerical range is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0013] In this specification, "adhesion" means that two surfaces are temporarily joined together by external pressure (microscopic pressure) based on the cohesive force of the chemical structure of the composition, and can be peeled off if necessary.

[0014] "Adhesion" refers to the joining of two surfaces by thermocompression or by chemical reaction (hardening) of a composition. In this specification, unless otherwise specified, the term "major component" refers to a component that is contained in an amount of more than 50% by mass. In this specification, percentages based on mass are synonymous with percentages based on weight.

[0015] [Thermal decomposition sheet] The thermally disintegrable sheet according to an embodiment of the present invention is a thermally disintegrable sheet having a thermally disintegrable layer, the thermally disintegratable layer contains a resin and an inorganic expanding agent, The content of the inorganic expanding agent relative to 100 parts by mass of the resin is 10 parts by mass or more, The adhesive strength of the thermally disintegrable sheet is 1.0 N / 20 mm or less. The thermally disintegrable sheet according to an embodiment of the present invention has a thermally disintegrable layer containing a specific amount of inorganic expanding agent, which expands when stimulated by heat, reducing adhesive strength and allowing for easy disintegration. The adhesive strength of the thermally disintegrable sheet is measured at room temperature. Setting the adhesive strength of the thermally disintegrable sheet to 1.0 N / 20 mm or less results in low adhesiveness at room temperature, preventing the sheet from sticking to an adherend when placed on it, making it easy to adjust its position and providing excellent handling when producing a bonded structure.

[0016] The thermally disintegrable sheet according to an embodiment of the present invention can be strongly bonded to an adherend by being placed on the adherend and then heated and pressed or cured, and two or more adherends can be bonded together via the thermally disintegrable sheet (which may be a thermally disintegrable layer) to form a bonded body.

[0017] Fig. 1 is a schematic cross-sectional view showing a thermally disintegrable sheet according to an embodiment of the present invention. As shown in Fig. 1, the thermally disintegrable sheet 100 according to this embodiment includes a thermally disintegrable layer, and may consist of only a thermally disintegrable layer 11. Although Fig. 1 shows a thermally disintegrable layer having a single-layer structure, the thermally disintegrable layer may have a multi-layer structure of two or more layers.

[0018] The thermally disintegrable sheet of this embodiment may include a resin layer 12 as shown in Fig. 2. The thermally disintegrable sheet of this embodiment may also include other layers such as a thermally disintegrable layer 11 and a resin layer 12. There are no particular restrictions on the layers other than the thermally disintegrable layer 11 and the resin layer 12, and known layers can be used depending on the application of the thermally disintegrable sheet, the material of the adherend, etc.

[0019] Fig. 3 is a schematic cross-sectional view showing one embodiment of a bonded structure bonded by a thermally disintegrable sheet according to an embodiment of the present invention. The bonded structure 200 shown in Fig. 3 is a bonded structure in which a first member 14 and a second member 15 are bonded via a thermally disintegrable layer 11 as an adherend.

[0020] As described above, the thermally disintegrable sheet according to the embodiment of the present invention preferably includes a thermally disintegrable layer, but may consist of only a thermally disintegrable layer. The thermally disintegrable sheet according to the present embodiment may be a sheet with a supporting substrate in a form in which the thermally disintegrable layer is provided on one or both sides of a sheet-like substrate (supporting substrate), or may be a substrate-less thermally disintegrable sheet in a form in which at least one surface of the thermally disintegrable layer is supported by a release liner. That is, the thermally disintegrable sheet according to an embodiment of the present invention may be a thermally disintegrable sheet with a release liner (hereinafter, sometimes simply referred to as a thermally disintegrable sheet) in which at least one surface of the thermally disintegrable layer in the thermally disintegrable sheet is protected by a release liner.

[0021] The thermally disintegrable layer is typically formed continuously, but is not limited to this form, and may be formed in a regular or random pattern such as dots or stripes. The thermally disintegrable layer of this embodiment may be in the form of a roll or sheets. Alternatively, it may be a thermally disintegrable sheet processed into various shapes.

[0022] (Adhesive strength of thermally disintegrable sheet) The adhesive strength of the thermally disintegrable sheet according to an embodiment of the present invention is 1.0 N / 20 mm or less. When the thermally disintegrable layer is a thermally disintegrable sheet, the adhesive strength of the thermally disintegrable layer must be 1.0 N / 20 mm or less. If the adhesive strength of the thermally disintegrable layer is greater than 1.0 N / 20 mm, a resin layer or the like may be provided on the surface of the thermally disintegrable layer to form a thermally disintegrable sheet with an adhesive strength of the outermost surface of 1.0 N / 20 mm or less. The adhesive strength of the thermally disintegrable sheet was measured by transferring it to a 75μm PET substrate, cutting out a test piece measuring 25mm wide x 12.5mm, and bonding it to an aluminum plate A5052P. After 30 minutes, the adhesive strength was measured using a tensile tester at 23°C, 50% RH, at a pulling speed of 300mm / min and a peel angle of 180°.

[0023] By setting the adhesive strength of the thermally disintegratable sheet according to the embodiment of the present invention to 1.0 N / 20 mm or less, handling is excellent, making it easier to re-stick or adjust the position when laminated on an adherend, and improving work efficiency when producing a joined body. The adhesive strength of the thermally disintegratable sheet according to the embodiment of the present invention is preferably 2.0 N / 20 mm or less, and more preferably 1.0 N / 20 mm or less, from the viewpoint of preventing contamination of the adherend due to re-sticking.

[0024] (Expansion ratio of thermally disintegrable sheet) The thermally disintegrable sheet according to an embodiment of the present invention has an expansion ratio in the thickness direction of 2.0 times or more after being heated at 250°C for 10 minutes. The thermally disintegrable sheet according to an embodiment of the present invention has an expansion ratio in the thickness direction of 2.0 times or more after heating at 250°C for 10 minutes, which reduces the adhesive strength upon heating and enables the thermally disintegrable layer to be easily disassembled. From the viewpoint of the fracture morphology of the thermally disintegrable layer, the expansion ratio in the thickness direction of the thermally disintegrable sheet according to an embodiment of the present invention after heating at 250°C for 10 minutes is preferably 3 times or more, and more preferably 4 times or more. There is no particular upper limit to the expansion ratio, but from the viewpoint of durability, it may be 5 times or less. The expansion ratio in the thickness direction of the thermally disintegrable sheet according to the embodiment of the present invention before and after heating can be calculated by measuring the thickness of the thermally disintegrable sheet before and after heating at 250°C. Specifically, the thickness of the joined body obtained using the thermally disintegratable sheet according to the embodiment of the present invention and the thickness of the joined body after heating at 250°C for 10 minutes and allowing it to cool to room temperature are measured, and the thickness can be calculated using the following formulas 1 and 2.

[0025]

number

[0026]

number

[0027] More specifically, the expansion ratio can be measured by the method described in the Examples.

[0028] <Thermodegradable layer> In the thermally disintegrable sheet according to an embodiment of the present invention, the thermally disintegrable layer contains a resin and an inorganic expanding agent, and the content of the inorganic expanding agent per 100 parts by mass of the resin is 10 parts by mass or more. The thermally disintegrable layer may further contain an inorganic filler. The thermally disintegrable layer is preferably a sheet-like layer.

[0029] As mentioned above, when the thermally disintegrable layer is made into a thermally disintegrable sheet, the adhesive strength of the thermally disintegrable layer must be 1.0 N / 20 mm or less. If the adhesive strength of the thermally disintegrable layer is greater than 1.0 N / 20 mm, a resin layer or the like may be provided on the surface of the thermally disintegrable layer to form a thermally disintegrable sheet with an adhesive strength of the outermost surface of 1.0 N / 20 mm or less.

[0030] The thermally disintegrable layer is preferably cured by at least one of a polymerization reaction and a crosslinking reaction of the resin contained in the thermally disintegrable layer. That is, the resin contained in the thermally disintegrable layer may have a reactive functional group. Furthermore, it is preferable that the resin layer according to the embodiment of the present invention can be further cured by at least one of a polymerization reaction and a crosslinking reaction after being attached to the adherend.

[0031] The thermally disintegrable layer can be formed into a sheet from a thermally disintegrable composition. The thermally disintegrable composition contains a resin and an inorganic expanding agent, and can be formed into a sheet to form a thermally disintegrable layer. The thermally disintegrable composition may further contain an inorganic filler.

[0032] (resin) The resin contained in the thermally disintegrable layer according to the embodiment of the present invention is not particularly limited, and may be at least one type of resin, and preferably two or more types of resin. Examples of resins according to the embodiment of the present invention include thermoplastic resins and thermosetting resins, and from the viewpoint of recyclability, it is preferable to include a thermoplastic resin.

[0033] Examples of thermosetting resins include phenolic resins, urea resins, melamine resins, diallyl phthalate resins, polyester resins, epoxy resins, aniline resins, silicone resins, furan resins, polyurethane resins, alkylbenzene resins, alkyd resins, guanamine resins, xylene resins, and imide resins. Among these, it is preferable to use epoxy resins because of their excellent curability and heat resistance of the cured product.

[0034] Examples of epoxy resins include bisphenol A, bisphenol F, bisphenol S, brominated bisphenol A, hydrogenated bisphenol A, bisphenol AF, biphenyl, naphthalene, fluorene, phenol novolac, cresol novolac, orthocresol novolac, trishydroxyphenylmethane, tetraphenylolethane, hydantoin, trisglycidyl isocyanurate, and glycidylamine epoxy resins. Among these, bisphenol A epoxy resins are preferred.

[0035] Furthermore, as the thermosetting resin, a thermoplastic resin having a thermosetting functional group can also be used. Examples of the thermosetting functional group include an acrylate group, an epoxy group, an oxetane group, an isocyanate group, and a silanol group. Examples of the thermoplastic resin having a thermosetting functional group include a thermosetting functional group-containing resin. Examples of the thermosetting functional group-containing resin include an acrylic-modified resin, a polyurethane-modified resin, an epoxy-modified resin, a phenol-modified resin, a polyether-modified resin, and a silicone-modified resin. From the viewpoint of achieving high adhesive strength, an epoxy-modified resin is preferred.

[0036] More specifically, examples of the thermosetting functional group-containing resin include polyurethane-modified acrylic resin, acrylic-modified polyurethane resin, epoxy-modified acrylic resin, epoxy-modified polyurethane resin, o-cresol-modified resin, phenol-modified acrylic resin, phenol-modified polyurethane resin, phenol-modified epoxy resin, polyether-modified acrylate resin, and silicone-modified acrylate resin. The resin contained in the thermally disintegratable layer according to the embodiment of the present invention preferably contains an epoxy-modified resin from the viewpoint of adhesion to the adherend.

[0037] Examples of the acrylic resin in the thermosetting functional group-containing acrylic resin include those containing a monomer unit derived from a (meth)acrylic acid ester. In the case of a thermoplastic resin having a thermosetting functional group, a curing agent is selected depending on the type of the thermosetting functional group.

[0038] Furthermore, examples of thermoplastic resins include natural rubber, butyl rubber, isoprene rubber, styrene rubber (e.g., styrene-butadiene rubber, styrene-isoprene rubber, styrene-ethylene-propylene-styrene rubber, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer, styrene-ethylene-propylene block copolymer, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resins such as polyamide 6 and polyamide 6,6, phenoxy resin, thermoplastic acrylic resin, saturated polyester resins such as PET and PBT, polyamide-imide resin, fluororesin, polypropylene resin, polyphenylene ether, polyphenylene sulfide, polyether sulfide, and epoxy. The thermoplastic resins may be used singly or in combination of two or more.

[0039] The thermoplastic acrylic resin is preferably a polymer containing a monomer unit derived from a (meth)acrylic acid ester as the most abundant monomer unit by mass. Examples of (meth)acrylic acid esters include (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters. The acrylic resin may also contain a monomer unit derived from another component copolymerizable with the (meth)acrylic acid ester. Examples of the other component include functional group-containing monomers such as carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphate group-containing monomers, acrylamides, and acrylonitriles, as well as various polyfunctional monomers.

[0040] The resin contained in the thermally disintegratable layer according to the embodiment of the present invention preferably contains at least one selected from polyamide resin, acrylic rubber, and epoxy resin, from the viewpoint of reducing the elastic modulus in the heating temperature range during dismantling.

[0041] The polyamide resin is not particularly limited as long as it has an amide bond as a repeating unit in the main chain, and examples thereof include polymers of aliphatic or aromatic diamines and aliphatic or aromatic dicarboxylic acids, ring-opening polymers of cyclic lactams, etc. These may be used alone or in combination of two or more.

[0042] Examples of acrylic rubber include NBR (nitrile butadiene rubber), carboxy-terminated butadiene-acrylonitrile copolymer rubber (CTBN), copolymers of acrylic esters and 2-chloroethyl vinyl ether, copolymers of acrylic esters and acrylonitrile, and copolymers of acrylic esters and acrylic acid. The acrylic rubbers can be used alone or in combination of two or more kinds.

[0043] Commercially available resins may be used. For example, commercially available polyamide resins include "Platamid M1276" and "Platamid HX2519" (manufactured by Arkema) and "Fine Resin FR-105" (manufactured by Lead City Co., Ltd.). Commercially available epoxy resins include "jER1256," "jER1256B40," and "jER4250" (manufactured by Mitsubishi Chemical Corporation), "YP-50S," "YP-50," "YP-70," and "FX-316" (manufactured by Nippon Steel Chemical & Materials Co., Ltd.). Thermoplastic acrylic resins include acrylic rubbers such as "HyPoxRK84L" (manufactured by Huntsman).

[0044] The above resins may be used alone or in combination of two or more. From the viewpoint of improving the dismantling property during thermal dismantling and the molding processability of the thermally dismantlable layer, the above resin is preferably a thermoplastic resin, and more preferably a polyamide resin, an epoxy resin, or an acrylic rubber. Furthermore, the resin preferably contains an epoxy-modified resin. By including an epoxy-modified resin in the resin, a strong bond with the adherend interface can be achieved during bonding.

[0045] The blending ratio of the resin is, for example, 50 parts by mass or more, preferably 80 parts by mass or more, more preferably 90 parts by mass or more, and for example, 100 parts by mass or less, preferably 99 parts by mass or less, more preferably 98 parts by mass or less, relative to 100 parts by mass of all resin components in the thermally disintegratable composition.

[0046] (hardening agent) A curing agent can also be blended into the thermally degradable composition, which provides the effect of increasing durability.

[0047] The curing agent is a component that reacts with the resin to cure the thermally disintegrable layer when the thermally disintegrable composition contains the resin. The curing agent may be appropriately selected from curing agents that can cure the resin depending on the type and composition of the resin used.

[0048] For example, when the resin contains an epoxy resin, the curing agent is preferably an epoxy resin curing agent. The epoxy resin curing agent is preferably a latent curing agent, which can achieve stronger adhesion to the interface of the adherend by reacting with the adherend when the epoxy resin is joined. The epoxy resin curing agent may be a thermosetting or photocuring curing agent, and is preferably a thermosetting or photocuring latent curing agent. The epoxy resin curing agent may be a thermosetting curing agent, and is preferably a thermosetting latent curing agent.

[0049] Furthermore, when a resin having a crosslinked structure is blended into the thermally disintegrable composition, a curing agent can be blended when preparing the thermally disintegrable composition to control the crosslinked structure after curing. A crosslinking agent or curing accelerator can be used as the curing agent, which makes it easier to set the elastic modulus E' of the thermally disintegrable layer within a specific range.

[0050] Examples of the curing agent include an isocyanate-based crosslinking agent, an aziridine-based crosslinking agent, an epoxy-based crosslinking agent, a silane-based crosslinking agent, a metal chelate-based crosslinking agent, an amine-based curing agent, an amide-based curing agent, a phenol-based curing agent, and an acid anhydride, and preferably an isocyanate-based crosslinking agent.

[0051] Examples of the isocyanate crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; aromatic diisocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate and polymethylene polyphenyl isocyanate; trimethylolpropane / tolylene diisocyanate trimer adduct (for example, manufactured by Mitsui Chemicals, Inc., trade name: D-101E), trimethylolpropane / hexamethylene diisocyanate trimer adduct (for example, manufactured by Tosoh Corporation, trade name: Coronate HL), and isocyanurate of hexamethylene diisocyanate (for example, manufactured by Tosoh Corporation, trade name: , trade name: Coronate HX); trimethylolpropane adduct of xylylene diisocyanate (e.g., Mitsui Chemicals, Inc., trade name: Takenate D110N), trimethylolpropane adduct of xylylene diisocyanate (e.g., Mitsui Chemicals, Inc., trade name: Takenate D120N), trimethylolpropane adduct of isophorone diisocyanate (e.g., Mitsui Chemicals, Inc., trade name: Takenate D140N), trimethylolpropane adduct of hexamethylene diisocyanate (e.g., Mitsui Chemicals, Inc., trade name: Takenate D160N); polyether polyisocyanate, polyester polyisocyanate, and adducts thereof with various polyols; and polyisocyanates multifunctionalized with isocyanurate bonds, biuret bonds, allophanate bonds, etc.

[0052] As the epoxy-based crosslinking agent, a multifunctional epoxy compound having two or more epoxy groups in one molecule can be used. Examples of the epoxy-based crosslinking agent include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol. Examples of epoxy resins include diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Commercially available epoxy crosslinking agents include diglycidylaniline, N,N,N',N'-tetraglycidyl-m-xylylenediamine (manufactured by Mitsubishi Gas Chemical Company, Inc., trade name: TETRAD-X), and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Company, Inc., trade name: TETRAD-C). These compounds may be used alone or in combination of two or more.

[0053] Examples of silane crosslinking agents include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.), 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane.

[0054] Examples of amine and amide curing agents that can be used include diethylenetriamine (DETA), diaminodiphenylmethane (DDM), dicyandiamide, and polyamide, and preferably dicyandiamide (for example, Omicure DDA-50, manufactured by Huntsman Co., Ltd.). Examples of phenol-based curing agents include phenol novolac resins, aralkyl-type phenol resins, dicyclopentadiene-modified phenol resins, naphthalene-type phenol resins, and bisphenol-based phenol resins.

[0055] Examples of the curing accelerator that can be used include imidazole compounds, tertiary amine compounds, phosphine compounds, and urea compounds. Imidazole compounds include various grades of the "Curezol" series marketed by Shikoku Chemical Industry Co., Ltd., and examples of suitable imidazole compounds include "Curezol 2MZA-PW" (manufactured by Shikoku Chemical Industry Co., Ltd.), "Curezol 2PHZ-PW" (manufactured by Shikoku Chemical Industry Co., Ltd.), and "Curezol 2MA-OK" (manufactured by Shikoku Chemical Industry Co., Ltd.). Examples of urea compounds include Omicure U-52 (manufactured by CVC Thermoset Specialties) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) (manufactured by Hodogaya Chemical Co., Ltd.). The curing accelerators can be used alone or in combination of two or more.

[0056] The blending ratio of the curing agent in the thermally degradable composition can be appropriately selected depending on the types of curing agent and curing accelerator.

[0057] The blending ratio of the curing agent in the thermally disintegratable composition is, relative to 100 parts by mass of the resin, for example, 0.1 part by mass or more, or preferably 0.3 part by mass or more, and for example, 20 parts by mass or less, or preferably 15 parts by mass or less, thereby adjusting the elastic modulus E' of the thermally disintegratable layer.

[0058] (inorganic leavening agent) In the thermally disintegrable sheet according to an embodiment of the present invention, the thermally disintegrable layer contains an inorganic expanding agent, and the content of the inorganic expanding agent relative to 100 parts by mass of the resin is 10 parts by mass or more.

[0059] In the thermally disintegrable sheet according to an embodiment of the present invention, the thermally disintegrable layer contains an inorganic expansion agent, and therefore, by heating the thermally disintegrable layer, the inorganic expansion agent in the thermally disintegrable layer expands at the desired timing, destroying the thermally disintegrable layer and reducing the adhesive strength, thereby enabling the joined body to be disassembled.

[0060] Examples of inorganic expanding agents include expanded graphite, vermiculite, silicates, vermullandite, aluminum phosphate, tammagite, and hydrosaltite, with expanded graphite and silicates being preferred. The inorganic expanding agents can be used alone or in combination of two or more.

[0061] Expanded graphite is produced by treating natural graphite, pyrolytic graphite, kish graphite, etc. with sulfuric acid, sodium nitrate, potassium permanganate, bromine, halides, etc. to form an intercalation compound between the graphite layers. By heat treating this at high temperatures, gas is generated from the intercalation compound, which causes the spaces between the graphite layers to expand in the direction perpendicular to the carbon planes. The thermally disintegrable layer according to an embodiment of the present invention contains an inorganic expansion agent. Therefore, when heat is applied to an assembly formed using the thermally disintegrable sheet, the inorganic expansion agent expands and easily destroys the thermally disintegrable layer, allowing the assembly to be disassembled without damaging the adherends.

[0062] When expanded graphite is used as the inorganic expanding agent, the particle size of the expanded graphite particles before expansion is preferably 0.1 to 400 μm, more preferably 10 to 200 μm. If the particle size is 0.1 μm or more, the degree of expansion is excellent, and if it is 400 μm or less, the influence of a decrease in adhesive strength is small.

[0063] The expansion starting temperature is preferably 130 to 400°C, more preferably 180 to 350°C, in view of the temperature at which the thermally disintegrable layer is formed from the thermally disintegrable composition, and the relationship between heat resistance durability and disintegrability when the bonded body is in use.

[0064] Furthermore, the thermally disintegrable layer (thermally disintegrable composition) may contain an expansion aid, if necessary.

[0065] In the thermally disintegrable sheet according to an embodiment of the present invention, the content of the inorganic expanding agent relative to 100 parts by mass of the resin is 10 parts by mass or more. The content of the inorganic expanding agent is 10 parts by mass or more, preferably 15 parts by mass or more, and more preferably 20 parts by mass or more, per 100 parts by mass of the resin, from the viewpoint of facilitating cohesive failure and interfacial failure of the thermally disintegrable layer, and is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, from the viewpoint of suppressing cohesion of the inorganic expanding agent.

[0066] In addition to inorganic expanding agents, microcapsules containing substances that are easily gasified and expand when heated, such as isobutane, propane, and pentane, within a shell (outer shell) made of an elastic outer shell material can also be used as thermally expandable particles.

[0067] Examples of the shell material (material forming the shell) of the microcapsules used in the present invention include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, polysulfone, etc. Microcapsules can be produced by conventional methods, such as coacervation and interfacial polymerization.

[0068] The glass transition temperature (Tg) of the shell material of the microcapsules is preferably 92°C or higher, more preferably 92 to 200°C, and even more preferably 93 to 180°C.

[0069] Commercially available microcapsules can also be used. Examples of commercially available microcapsules include, but are not limited to, products under the trade names "Matsumoto Microsphere F-80S" (expansion start temperature: 140-150°C), "Matsumoto Microsphere F-190D" (expansion start temperature: 160-170°C), "Matsumoto Microsphere F-230D" (expansion start temperature: 180-190°C), and "Matsumoto Microsphere F-260D" (expansion start temperature: 190-200°C) (all manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.); and products under the trade names "Expancel Microsphere 051DU40" (expansion start temperature: 108-113°C), "Expancel Microsphere 461DU40" (expansion start temperature: 98-104°C), and "Expancel Microsphere 920DU40" (expansion start temperature: 123-133°C) (all manufactured by Expancel).

[0070] The average particle size of the microcapsules is generally about 1 to 80 μm, preferably about 3 to 50 μm, from the viewpoints of dispersibility and thin layer formation.

[0071] (filler) The thermally disintegrable composition (which may be the thermally disintegrable layer) may further contain a filler. The type and amount of filler to be added are not particularly limited. The thermally disintegrable composition (which may be the thermally disintegrable layer) contains a filler, which makes it possible to adjust the shear adhesive strength and elastic modulus E' of the thermally disintegrable layer.

[0072] The proportion of the filler in the thermally disintegratable composition (which may be the thermally disintegratable layer) is not particularly limited, and is preferably 0.1 to 50 parts by mass, 0.5 to 40 parts by mass, more preferably 1 to 30 parts by mass, more preferably 5 to 21 parts by mass, and more preferably 10 to 20 parts by mass, relative to 100 parts by mass of the thermally disintegratable composition. If the proportion is less than 0.1 part by mass, a sufficient improvement in the elastic modulus cannot be obtained. If the content exceeds 50 parts by mass, it becomes difficult to form the thermally disintegratable layer.

[0073] The filler is not particularly limited, and may be non-particulate such as fibrous, bundle-like, plate-like, layer-like, needle-like, spike-like, or amorphous, fine particles, secondary particles (aggregates) of fine particles, solid particles, or hollow particles. The filler may be organic or inorganic fine particles, and is not limited thereto, but is preferably inorganic fine particles.

[0074] ((Inorganic fine particles)) Examples of inorganic fine particles that can be blended into the thermally disintegratable composition of the present invention include metal oxides such as silica, alumina, zirconia, and titania; metal salts such as aluminum borate and aluminum hydroxide; minerals such as mica; and inorganic fine particles having a hollow structure such as hollow nanosilica. These can be used alone or in combination of two or more.

[0075] ((Organic fine particles)) Examples of organic fine particles that can be incorporated into the thermally disintegratable composition of the present invention include fine particles composed of polymers such as styrene resins, acrylic resins, silicone resins, acrylic-styrene resins, vinyl chloride resins, vinylidene chloride resins, amide resins, urethane resins, phenol resins, styrene-conjugated diene resins, acrylic-conjugated diene resins, olefin resins, and fluorine-based resins, as well as crosslinked products of these polymers, and fine particles composed of these crosslinked polymers to have a hollow structure. These can be used alone or in combination of two or more types.

[0076] The inorganic fine particles may be surface-treated to improve dispersibility in the thermally decomposable composition. Any known or commonly used surface treatment agent can be used without limitation. Examples of such surface treatment agents include silane coupling agents, titanium coupling agents, organic acids, polyols, and silicones. Silane coupling agents are preferred. Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, dimethylvinylmethoxysilane, dimethylvinylethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, vinyltris(2-methoxy)silane, vinyltriacetoxysilane, 2-methacryloxyethyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, triethoxyphenylsilane, trimethoxyphenylsilane, dimethoxydiphenylsilane, methyldiethoxyphenylsilane, and dimethoxymethylphenylsilane.

[0077] The surface of the filler is not particularly limited. For example, the filler may be untreated or may be surface-treated, but it is preferred that the surface of the filler is untreated or that the functional group on the surface of the filler is at least one group selected from the group consisting of a silanol group, a hydroxyl group, an amino group, a mercapto group, a carboxyl group, an isocyanate group, and an epoxy group.

[0078] Examples of the filler include silica particles such as fumed silica, colloidal silica, and precipitated silica, and silica-based fillers such as silica gel, silica aerogel, quartz glass, and glass fiber. Among these, fumed silica and colloidal silica are preferred from the viewpoint of being easily mixed into the thermally disintegratable composition.

[0079] As the fumed silica, a general commercially available product can be used, for example, hydrophobic fumed silica manufactured by Nippon Aerosil Co., Ltd., and specific examples include products manufactured by Nippon Aerosil Co., Ltd. under the trade names "AEROSIL (registered trademark) RX series" (RX50, RX200, RX300, etc.), "AEROSIL (registered trademark) RY series" (RY50, RY200, RY200S, etc.), "AEROSIL (registered trademark) NY50 series," "AEROSIL (registered trademark) NAX series," and "AEROSIL (registered trademark) R series."

[0080] The thermally disintegratable composition may contain appropriate additives depending on the application of the thermally disintegratable sheet, such as leveling agents, crosslinking aids, plasticizers, softeners, antistatic agents, ultraviolet absorbers, fillers, antioxidants, antioxidants, light stabilizers, colorants (pigments, dyes, etc.), foaming agents, etc. As for such various additives, conventionally known ones can be used in the usual manner, and detailed description thereof will be omitted since they do not particularly characterize the present invention.

[0081] The method for preparing the thermally disintegratable composition is not particularly limited, and for example, a liquid composition containing each component and, if necessary, a solvent is prepared, and the composition can be obtained using a planetary centrifugal mixer. The thermally disintegrable layer may be formed into a sheet by applying the thermally disintegrable composition onto the substrate, drying it, and removing the solvent.

[0082] When forming a thermally disintegrable layer by applying a thermally disintegrable composition, the application can be carried out using a conventional coater such as a gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, etc. In the thermally disintegrable sheet having a supporting substrate described below, the method of providing a thermally disintegrable layer on the supporting substrate may be a direct method in which the thermally disintegrable composition is directly applied to the supporting substrate to form a thermally disintegrable layer, or a transfer method in which a thermally disintegrable layer formed on a release surface is transferred to the substrate.

[0083] As another method for preparing the thermally disintegrable composition, the composition can be obtained by heating and kneading the components using a kneader such as a twin-screw kneader, a kneader, etc. The thermally disintegrable composition may also be obtained by compressing and stretching the composition by calendar molding, extrusion molding, press molding, or the like to form the thermally disintegrable layer into a sheet shape.

[0084] The thickness of the thermally disintegratable layer is not particularly limited and is, for example, 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and for example, 3000 μm or less, preferably 1000 μm or less, more preferably 500 μm or less.

[0085] Parameters (thermal decomposable layer) (Elastic modulus E' of thermally degradable layer) In the thermally disintegrable sheet according to an embodiment of the present invention, the thermally disintegrable layer is Elastic modulus E' at 25°C 25 is 10 5 Pa or more 10 10 Pa or less, Elastic modulus E' at 120°C 120 is 10 4 Pa or more 10 8 Pa or less, Elastic modulus E' at 250℃ 250 is 10 5 It is preferable that the viscosity is less than or equal to Pa.

[0086] The thermally disintegratable layer according to the embodiment of the present invention has an elastic modulus E' at 25°C from the viewpoint of handling. 25 is 10 5 Pa or more, and 6 More preferably, 10 Pa or more. 7 More preferably, the temperature is 10 Pa or higher. 8 From the viewpoint of enhancing adhesive strength, the modulus of elasticity E' at 25°C is more preferably 1 Pa or more. 25 is 10 10 Pa or less, and 9 It is more preferable that the viscosity is 0.05 Pa or less.

[0087] From the viewpoint of heat resistance, the thermally disintegratable layer according to the embodiment of the present invention has an elastic modulus E' at 120°C. 120 is 10 4 Pa or more, and 5 From the viewpoint of suppressing flow, the elastic modulus E' at 120°C is more preferably equal to or greater than 1 Pa. 120 is 10 8 Pa or less, and 7 It is more preferable that the viscosity is 0.05 Pa or less.

[0088] From the viewpoint of heat resistance, the thermally disintegratable layer according to the embodiment of the present invention has an elastic modulus E' at 250°C. 250 is 10 3 Pa or more, and 4 From the viewpoint of dismantling property, the elastic modulus E' at 250°C is more preferably 1 Pa or more. 250 is 10 7 Pa or less, and 6 It is more preferable that the viscosity is 0.05 Pa or less.

[0089] The elastic modulus E' of the thermally disintegrable layer is dynamic viscoelasticity measured with a viscoelasticity measuring device. When the thermally disintegrable layer contains a curing agent, the dynamic viscoelasticity is measured with a viscoelasticity measuring device after the thermally disintegrable layer has been cured. Specifically, the produced thermally disintegrable layer is cut into a piece 10 mm wide x 50 mm long, and the dynamic viscoelasticity can be measured using a rheometer (product name "RSA G2", manufactured by TA Instruments) under conditions of a frequency of 1 Hz, a heating rate of 5°C / min, and a measurement temperature of -40 to 200°C. In this manner, the dynamic viscoelasticity of the thermally disintegrable layer is measured at each temperature, and this is taken as the elastic modulus E'. More specifically, it can be measured by the method described in the Examples.

[0090] (resin layer) The thermally disintegrable sheet according to the embodiment of the present invention may further have a resin layer. This resin layer may be, for example, an outermost layer provided for the purpose of adjusting the adhesive strength of the thermally disintegrable sheet. The resin layer can be formed from a resin composition containing a resin component (hereinafter, the resin layer, resin component, and resin composition component may be referred to as resin layer B, resin component B, and resin composition component B, respectively). Examples of the resin component B include polyethylene resins (low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, very low-density polyethylene, etc.), polypropylene resins (random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, etc.), polybutene, polymethylpentene, ionomers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester (random, alternating) copolymers, ethylene-vinyl acetate copolymers (EVA), ethylene-propylene copolymers, cyclic olefin polymers, ethylene-butene copolymers, ethylene- Examples of suitable resins include polyolefin resins such as hexene copolymers; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, and polybutylene terephthalate (PBT); polycarbonates; polyimide resins; polyether ether ketones; polyetherimides; polyamides such as aramids and wholly aromatic polyamides; polyphenyl sulfides; fluororesins; polyvinyl chloride; polyvinylidene chloride; cellulose resins such as triacetyl cellulose (TAC); silicone resins; acrylic resins such as polymethyl methacrylate (PMMA); polysulfones; polyarylates; and polyvinyl acetates. Only one of the above resins may be used, or two or more may be used. From the viewpoint of reducing adhesive strength and durability, the resin component A is preferably polyamide or epoxy, and more preferably polyamide.

[0091] The resin layer B (resin composition A) may further contain a curing agent. The curing agent is a component that reacts with resin component B to cure the resin layer. Examples of the curing agent include the same curing agents used in the thermally disintegrable layer. The curing agent may be appropriately selected from curing agents capable of curing resins depending on the type and composition of the resin used as resin component B. Among these, epoxy-based crosslinking agents are preferred. Commercially available epoxy-based crosslinking agents include diglycidyl aniline, N,N,N',N'-tetraglycidyl-m-xylylenediamine (manufactured by Mitsubishi Gas Chemical Company, Inc., trade name: TETRAD-X), and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Company, Inc., trade name: TETRAD-C). These compounds may be used alone or in combination of two or more.

[0092] The blending ratio of the curing agent in the resin layer B can be appropriately selected depending on the type of curing agent and curing accelerator. The blending ratio of the curing agent in resin layer B is, for example, 0.1 part by mass or more, preferably 0.3 part by mass or more, and for example, 20 parts by mass or less, preferably 15 parts by mass or less, relative to 100 parts by mass of resin B. This may adjust the adhesive strength of resin layer B, or the adhesive strength of the thermally disintegrable sheet may be adjusted by providing resin layer B as the outermost layer of the thermally disintegrable sheet.

[0093] The thickness of the resin layer B is usually 1 μm or more. In one embodiment, the thickness of the resin layer B may be 2 μm or more. In another embodiment, the thickness of the resin layer B may be 5 μm or more, 10 μm or more, or 50 μm or more.

[0094] The method for preparing the resin composition is not particularly limited, and it can be prepared by the same method as for the thermally disintegratable composition. The method for forming the resin layer is not particularly limited, and it can be formed by the same method as for the thermally disintegratable layer.

[0095] (Supporting base material) Furthermore, as described above, the thermally disintegrable sheet of this embodiment may include a supporting substrate. That is, the thermally disintegrable sheet of this embodiment may further include a supporting substrate, and the thermally disintegrable layer may be provided on at least one surface of the supporting substrate. This allows the thermally disintegrable sheet to be processed with high precision by punching or the like. Such a thermally disintegrable sheet is also preferred for applications in which it is processed into a specific shape or is used in a narrow width.

[0096] Furthermore, the thickness of the supporting substrate in this embodiment is preferably 100 μm or less, more preferably 80 μm or less, even more preferably 70 μm or less, even more preferably 50 μm or less, and particularly preferably 30 μm or less. In one aspect, the thickness of the supporting substrate may be 20 μm or less, 12 μm or less, 7 μm or less, or 3 μm or less. There is no particular lower limit to the thickness of the supporting substrate. From the viewpoint of the handleability and processability of the thermally disintegratable sheet, the thickness of the supporting substrate is usually 0.5 μm or more (for example, 1 μm or more). In one aspect, the thickness of the supporting substrate may be 3 μm or more. In another aspect, the thickness of the supporting substrate may be 8 μm or more, or may be 13 μm or more, or may be 16 μm or more.

[0097] The structure and material of the supporting substrate are not particularly limited, and it is typically a film-like substrate (also referred to as a "substrate film"). As the substrate film, one containing a resin film as a base film can be preferably used. The base film is typically a member that can independently maintain its shape (independent). The substrate film in this embodiment may be substantially composed of such a base film. Alternatively, the substrate film may include an auxiliary layer in addition to the base film. Examples of the auxiliary layer include a colored layer, a reflective layer, an undercoat layer, an antistatic layer, etc., provided on the surface of the base film. The substrate film may also be a porous film. The porous film is not particularly limited as long as it has a plurality of pores in the film (as long as pores are formed), and examples thereof include foam films and nonwoven fabrics.

[0098] The resin film is a film whose main component is a resin material (e.g., a component contained in the resin film in an amount exceeding 50% by mass). Examples of resin films include polyolefin-based resin films such as polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymer; polyester-based resin films such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN); polyurethane-based resin films; vinyl chloride-based resin films; vinyl acetate-based resin films; polyimide-based resin films; polyamide-based resin films; fluororesin films; cellophane; and the like. The resin film may also be a rubber-based film such as a natural rubber film or a butyl rubber film. Among these, polyester films are preferred from the viewpoints of handleability and processability, and PET films are particularly preferred.

[0099] <Application> The thermally disintegrable sheet according to the embodiment of the present invention can be used for joining various adherends. The thermally disintegrable sheet according to the embodiment of the present invention can easily destroy the thermally disintegrable layer by applying a stimulus such as heat, and the joined body can be disassembled without damaging the adherends, so the sheet can be suitably used for joining adherends or adherends made of different materials that require separation and recovery, as well as for joining members.

[0100] The thermally disintegrable sheets according to the embodiments of the present invention are suitable for fastening and joining metal parts, resin parts, and metal-resin composite parts used in boats, aircraft, automobiles, etc. In particular, automobile batteries, bodies, motors, etc., are required to be separated and collected in consideration of environmental issues, and may require dismantling. Furthermore, because the thermally disintegrable sheets according to the embodiments of the present invention are in sheet form, they have excellent processing precision, making them suitable for applications where they can be processed into specific shapes or narrowed for use, such as fastening and joining components in portable electronic devices. Such portable electronic devices and other electronic devices may require dismantling for the purpose of separated collection, repair or replacement of components, etc.

[0101] [Laminate, Joined Body, Manufacturing Method of Joined Body, and Disassembly Method of Joined Body] The thermally disintegrable sheet according to the embodiment of the present invention can be used in a laminate, a bonded body, a method for manufacturing a bonded body, and a method for dismantling a bonded body.

[0102] The above description can be directly applied to the thermally disintegrable sheet and the thermally disintegrable layer in the laminate, the joined body, the method for manufacturing the joined body, and the method for dismantling the joined body according to the embodiments of the present invention.

[0103] (Laminate, Joint, and Method for Manufacturing Joint) The laminate according to the embodiment of the present invention is a laminate in which a thermally disintegrable sheet is laminated on a resin material. The laminate according to the embodiment of the present invention is preferably a laminate in which a thermally disintegrable layer of the thermally disintegrable sheet is laminated on a resin material. The laminate according to an embodiment of the present invention may be a laminate in which at least a portion of the surface of the thermally disintegratable layer in the thermally disintegratable sheet according to an embodiment of the present invention is laminated on at least a portion of the surface of the resin material, and it is preferable that the laminate is laminated so that at least a portion of the surface of the thermally disintegratable layer is in contact with at least a portion of the surface of the resin material.

[0104] The joined body according to the embodiment of the present invention is a joined body in which the thermally disintegrable sheet according to the embodiment of the present invention is joined to a resin material. The joined body according to the embodiment of the present invention is preferably a joined body in which the thermally disintegrable layer of the thermally disintegrable sheet is joined to a resin material. The bonded structure according to an embodiment of the present invention may be a bonded structure in which at least a portion of the surface of the thermally disintegratable layer in the thermally disintegratable sheet according to an embodiment of the present invention is bonded to at least a portion of the surface of the resin material, and it is preferable that at least a portion of the surface of the thermally disintegratable layer is bonded to at least a portion of the surface of the resin material. The bonded body according to the embodiment of the present invention may be a bonded body in which a resin material is a first member, and the first member and a second member are bonded together via a thermally disintegrable sheet.

[0105] When two or more adherends (e.g., a first member and a second member) are joined using a thermally disintegrable sheet according to an embodiment of the present invention, the thermally disintegrable sheet may be a sheet consisting of only a thermally disintegrable layer without a substrate, a sheet having the thermally disintegrable layer on both sides of a supporting substrate, or a sheet having the thermally disintegrable layer on one side of a supporting substrate and another adhesive layer on the other side. That is, in the laminate and bonded body according to the embodiment of the present invention, a supporting substrate, an adhesive layer other than the thermally disintegrable layer, and the like may be present between the adherend and the thermally disintegrable layer.

[0106] The method for producing a joined body according to an embodiment of the present invention uses a thermally disintegrable sheet according to an embodiment of the present invention. The bonded body may be manufactured and molded using a molding method such as compression molding, transfer molding, injection compression molding, RTM (Resin Transfer Molding) molding, VaRTM (Vacuum assisted Resin Transfer Molding) molding (vacuum impregnation method), autoclave molding, or the like.

[0107] The method for producing a joined body according to an embodiment of the present invention uses a thermally disintegrable sheet according to an embodiment of the present invention.

[0108] The manufacturing method of the joined body according to the embodiment of the present invention includes a lamination step of laminating the thermally disintegrable layer of the thermally disintegrable sheet according to the embodiment of the present invention and a resin material; The method may further include a fusion step of fusion-bonding the thermally disintegratable layer and the resin material.

[0109] A method for producing a joined body according to another embodiment of the present invention includes a laminating step of laminating the thermally disintegratable layer of the thermally disintegratable sheet and a substrate; an impregnation step of impregnating the substrate with a resin composition; a curing step of curing the resin composition to form a resin material; The device may also include:

[0110] Furthermore, the method for producing a bonded body according to the embodiment of the present invention may include a bonding step of curing the thermally disintegrable layer to bond two or more adherends together.

[0111] The resin material in the laminate, the bonded body, and the method for manufacturing the bonded body includes a resin. The resin included in the resin material may be a thermosetting resin or a thermoplastic resin, and examples thereof include polyimide resins, acrylic resins, epoxy resins, polyethernitrile resins, polyethersulfone resins, polyester resins (polyethylene terephthalate resins, polyethylene naphthalate resins, etc.), polyvinyl chloride resins, polyphenylene sulfide resins, polyetheretherketone resins, polyamide resins (so-called aramid resins, etc.), polyarylate resins, polycarbonate resins, and liquid crystal polymers.

[0112] Examples of thermoplastic resins include PP (polypropylene), PA (polyamide), PPE (polyphenylene ether), PPS (polyphenylene sulfide), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), POM (polyacetal), PEEK (polyether ether ketone), PC (polycarbonate), PES (polyether sulfide), EP (epoxy), etc. Among these resins, thermoplastic resins that can advantageously exhibit the effects of the present invention include PPS (polyphenylene sulfide), PA (polyamide), PES (polyether sulfide), and EP (epoxy).

[0113] As the thermoplastic resin, fiber reinforced thermoplastic resin (FRTP) can be used. Examples of fiber reinforced thermoplastic resins (FRTP) include carbon fiber reinforced thermoplastic resins (CFRTP) and glass fiber reinforced thermoplastic resins (GFRTP).

[0114] Examples of carbon fiber reinforced thermoplastic resins (CFRTP) include PPS-based carbon fiber reinforced thermoplastic resins, PA-based carbon fiber reinforced thermoplastic resins, PES-based carbon fiber reinforced thermoplastic resins, EP-based carbon fiber reinforced thermoplastic resins, and PP-based carbon fiber reinforced thermoplastic resins.

[0115] Examples of glass fiber reinforced thermoplastic resins (GFRTP) include PPS-based glass fiber reinforced thermoplastic resins, PA-based glass fiber reinforced thermoplastic resins, and PP-based glass fiber reinforced thermoplastic resins.

[0116] The resin contained in the resin material may be a thermosetting resin, or from the viewpoint of improving adhesion between the resin material or resin composition and the thermally disintegratable layer, may be a thermosetting epoxy resin or a thermosetting resin containing an unsaturated hydrocarbon group. Examples of thermosetting epoxy resins include bisphenol A, bisphenol F, bisphenol S, brominated bisphenol A, hydrogenated bisphenol A, bisphenol AF, biphenyl, naphthalene, fluorene, phenol novolac, cresol novolac, orthocresol novolac, trishydroxyphenylmethane, tetraphenylolethane, hydantoin, trisglycidyl isocyanurate, and glycidylamine epoxy resins. Among these, it is preferable to use at least one of bisphenol A, epoxy resin, and cresol novolac epoxy resin, and it is more preferable to use a combination of bisphenol A, epoxy resin, and cresol novolac epoxy resin. Examples of bisphenol A type epoxy resins include aliphatic modified bisphenol A type epoxy resins. Examples of the unsaturated hydrocarbon group-containing thermosetting resin include unsaturated polyester resin and vinyl ester resin, with unsaturated polyester resin being preferred. The thermosetting epoxy resin and unsaturated hydrocarbon group-containing thermosetting resin contained in the resin material include at least a part of the thermosetting epoxy resin and unsaturated hydrocarbon group-containing thermosetting resin that is in an uncured state.

[0117] The resin material may include a fiber-reinforced resin, and the thermosetting resin may be a fiber-reinforced thermosetting resin. Examples of the fiber-reinforced thermosetting resin include carbon fiber-reinforced thermosetting resin and glass fiber-reinforced thermosetting resin.

[0118] The resin material preferably contains a thermosetting resin, a reactive monomer, a curing agent, carbon fiber, or glass fiber. For example, an unsaturated hydrocarbon group-containing thermosetting resin, such as an unsaturated polyester resin, undergoes radical polymerization of the unsaturated hydrocarbon group in the thermosetting resin and the reactive monomer in the presence of a curing agent to form a polymer (three-dimensional crosslinking), thereby obtaining a cured product. When the resin contained in the resin material is an unsaturated polyester resin, for example, styrene is preferably used as the reactive monomer, and benzoyl peroxide (BPO) is preferably used as the curing agent.

[0119] The shape of the resin material is not particularly limited, but examples thereof include a plate having a flat surface, a plate having a curved surface, a plate having an uneven surface, a sheet, and a film. The thickness of the resin material is not particularly limited, but is, for example, 0.001 mm to 30 mm.

[0120] Examples of the substrate in the method for producing the bonded body include substrates formed of glass, resin (e.g., polyethylene, aramid, etc.), cellulose, carbon fiber, etc. These are preferably fiber assemblies, and the fiber assemblies may be, for example, nonwoven fabrics, woven fabrics, intersection-welded meshes, etc. More specific examples include glass cloth and carbon cloth.

[0121] The materials for the first and second members constituting the adherend and laminate are not particularly limited, but examples include metal materials such as copper, silver, gold, iron, tin, palladium, aluminum, nickel, titanium, chromium, zinc, etc., or alloys containing two or more of these, as well as inorganic materials such as the above-mentioned resin materials, alumina, zirconia, soda glass, quartz glass, and carbon. The resin composition used in the method for producing the bonded body is not particularly limited as long as it is a composition that can form a resin material, and examples thereof include resin compositions that can form the above-mentioned resin materials.

[0122] The adherend may have either a single layer structure or a multilayer structure, and the surface to which the thermally disintegrable sheet is attached (attachment surface) may be subjected to various surface treatments.

[0123] In a method for manufacturing a bonded body using a thermally disintegrable sheet configured in this manner, for example, the thermally disintegrable sheet is laminated between a first member and a second member, which are adherends. Then, by applying pressure and heating to the first member and the second member in a direction that brings them into close contact with each other, the first member and the thermally disintegrable layer are fused together, and the thermally disintegrable layer and the second member are fused together, resulting in a bonded body in which the first member and the second member are bonded via the thermally disintegrable sheet (which may be the thermally disintegrable layer). Thereafter, by hardening the thermally disintegrable layer of the bonded body bonded using the thermally disintegrable sheet, a bonded body in which the first member and the second member are more firmly bonded via the thermally disintegrable sheet (which may be the thermally disintegrable layer) is obtained.

[0124] (Method of dismantling the joint) A method for dismantling a bonded structure according to an embodiment of the present invention is a method for dismantling a bonded structure according to an embodiment of the present invention, The method includes heating at least a portion of the bonded body to destroy the thermally decomposable layer.

[0125] In the method for dismantling a bonded body according to the embodiment of the present invention, the heating temperature when at least a part of the bonded body is heated can be appropriately selected depending on the type of resin contained in the thermally dismantlable layer used in the bonded body.

[0126] In the method for dismantling a joined body according to an embodiment of the present invention, at least a portion of the joined body is heated, causing the inorganic expansion agent in the thermally disintegratable layer to expand and become the starting point for dismantling, thereby enabling the joined body to be dismantled without damaging the adherends. When the bonded structure according to the embodiment of the present invention is a bonded structure in which a first member and a second member, which are adherends, are bonded using the thermally disintegrable sheet, the first member and the second member can be separated without being damaged.

[0127] When two or more components are joined or separated using a thermally disintegrable sheet in this way, it is preferable to satisfy the relationship X≦Y≦Z, where the temperature when forming the thermally disintegrable layer is X°C, the temperature when hardening the thermally disintegrable layer is Y°C, and the temperature when destroying the thermally disintegrable layer and dismantling the joined body is Z°C. This relationship is true regardless of whether or not heat is used in forming, hardening, and dismantling the thermally disintegrable layer.

[0128] When heating, only the thermally disintegrable layer may be heated, or the entire bonded body may be heated. The heating method is not particularly limited, but examples include heating in a heating oven and heating by electromagnetic induction heating. The heating temperature is preferably 130° C. or higher, more preferably 150° C. or higher, and even more preferably 180° C. or higher. From the viewpoint of dismantling the adherend without deformation or deterioration, the heating temperature is preferably 400° C. or lower, more preferably 370° C. or lower, and even more preferably 350° C. or lower.

[0129] As described above, the present specification discloses the following: <1> A thermally disintegrable sheet having a thermally disintegrable layer, the thermally disintegratable layer contains a resin and an inorganic expanding agent, The content of the inorganic expanding agent relative to 100 parts by mass of the resin is 10 parts by mass or more, The adhesive strength of the thermally disintegratable sheet is 1.0 N / 20 mm or less. Thermally decomposable sheet. <2> The thermally disintegratable layer is Elastic modulus E' at 25°C 25 is 10 5 Pa or more 10 10 Pa or less, Elastic modulus E' at 120°C 120 is 10 4 Pa or more 10 8 Pa or less, Elastic modulus E' at 250℃ 250 is 10 5 Pa or less, <1> The thermally disintegrable sheet according to claim 1. <3> After heating at 250°C for 10 minutes, the expansion ratio in the thickness direction is 2.0 times or more. <1> The thermally disintegrable sheet according to claim 1. <4> The inorganic expanding agent is expanded graphite or a silicate. <1> The thermally disintegrable sheet according to claim 1. <5> The thermally disintegratable layer further comprises a filler. <1> The thermally disintegrable sheet according to claim 1. <6> The resin contains at least one selected from polyamide resin, acrylic rubber, and epoxy resin. <5> The thermally disintegrable sheet according to claim 1. <7> The resin includes an epoxy-modified resin. <5> The thermally disintegrable sheet according to claim 1. <8> Further, the resin layer is <1> The thermally disintegrable sheet according to claim 1. <9> <1> A thermally disintegrable sheet with a release liner, comprising the thermally disintegrable sheet according to claim 1 and a release sheet. <10> <1> ~ <8> 10. A laminate in which the thermally disintegrable sheet according to any one of claims 1 to 9 is laminated on a resin material. <11> <1> ~ <8> 10. A bonded body in which the thermally disintegratable sheet according to any one of claims 1 to 9 is bonded to a resin material. <12> the resin material is a first member, The first member and the second member are joined by the thermally disintegrable sheet. <11> The conjugate according to claim 1. <13> The resin material includes a thermosetting resin. <12> The conjugate according to claim 1. <14> <1> ~ <8> 1. A method for producing a bonded body using the thermally disintegrable sheet according to any one of claims 1 to 9. <15> a lamination step of laminating the thermally disintegratable sheet and a resin material; a fusion step of fusing the thermally disintegratable layer and the resin material, <13> A method for producing the bonded body according to claim 1. <16> a lamination step of laminating the thermally disintegrable sheet and a substrate; an impregnation step of impregnating the substrate with a resin composition; a curing step of curing the resin composition to form a resin material; Equipped with <13> A method for producing the bonded body according to claim 1. <17> <11> 2. A method for dismantling the bonded body according to claim 1, comprising the step of heating at least a part of the bonded body to destroy the thermally disintegrable layer. [Example]

[0130] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples in any way.

[0131] Example 1 A polyamide resin solution was obtained by adding a mixed solvent of ethanol (EtOH) / water = 60% by mass / 40% by mass to a polyamide copolymer (Amilan CM8000, manufactured by Toray Industries, Inc.) to a solids ratio of 20% by mass, and stirring thoroughly while heating at 60°C. The polyamide resin solution was mixed with 100 parts by mass of polyamide resin and 30 parts by mass of expandable graphite (GG210-200N, manufactured by NeoGraf Co., Ltd.) to obtain a thermally disintegratable composition. Next, the thermally disintegrable composition was applied to the release-treated surface of a 75 μm-thick PET release liner using an applicator so that the thickness after heating would be 100 μm, to prepare a layer. Next, the layer was heated at 100°C for 5 minutes in a thermostatic oven to obtain a thermally disintegrable layer (thermally disintegrable sheet) with a release liner. Further, a resin composition layer was prepared in the same manner as above except that it did not contain an inorganic expanding agent, and used as an evaluation specimen for evaluating the elastic modulus.

[0132] [Examples 2, 3, and 4, and Comparative Example 2] Thermally disintegrable sheets and evaluation specimens for evaluating elastic modulus were prepared in the same manner as in Example 1, except that the types and amounts of the various raw materials used to prepare the thermally disintegrable sheets were changed as shown in Table 1 or 2.

[0133] Example 4 A thermally disintegrable composition was obtained in the same manner as in Example 1, except that the types and amounts of the various raw materials used to prepare the thermally disintegrable sheet were changed as shown in Table 1. The thermally disintegrable composition was applied using an applicator to the release-treated surface of a 75 μm-thick PET release liner having a release-treated surface, so that the thickness after heating would be 100 μm, to obtain a layer. Next, the layer was heated at 100°C for 5 minutes to obtain a thermally disintegrable layer (thermally disintegrable sheet) with a release liner. Further, a resin composition layer was prepared in the same manner as above except that it did not contain an inorganic expanding agent, and used as an evaluation specimen for evaluating the elastic modulus.

[0134] [Examples 5, 6, and 7, and Comparative Example 3] Thermally disintegrable sheets and evaluation specimens for evaluating elastic modulus were prepared in the same manner as in Example 4, except that the types and amounts of the various raw materials used to prepare the thermally disintegrable sheets were changed as shown in Table 1 or 2.

[0135] Comparative Example 4 The raw materials and amounts shown in Table 2 were blended, dissolved in methyl ethyl ketone (MEK) as a solvent, and mixed at room temperature for 15 minutes using a rotary stirrer to prepare a thermally disintegrable composition. Next, the thermally disintegrable composition was applied to the release-treated surface of a 75 μm-thick PET release liner using an applicator so that the thickness after heating would be 100 μm, forming a layer. This was then heated at 80°C for 5 minutes to prepare a thermally disintegrable layer (thermally disintegrable sheet) with a release liner. For evaluation samples for elastic modulus evaluation, a resin composition layer was prepared in the same manner except that no inorganic expanding agent was added.

[0136] Comparative Example 5 A mixture containing 100 parts by mass of DGEBA (bisphenol A epoxy resin, manufactured by Tokyo Chemical Industry Co., Ltd.) and 29 parts by mass of DDM (diaminodiphenylmethane, manufactured by Tokyo Chemical Industry Co., Ltd.) was heated at 100°C for 15 minutes and allowed to cool. Next, 20 parts by mass of silica filler (M5 Cab-o-sil, manufactured by CABOT) and 30 parts by mass of expandable graphite (GG210-200N, manufactured by NeoGraf) were added to obtain the thermally disintegrable composition shown in Table 1. A resin composition was prepared in the same manner as above, except that no inorganic expanding agent was added, and used as an evaluation specimen for evaluating the elastic modulus.

[0137] Example 8 A thermally disintegrable sheet with a thermally disintegrable layer was obtained in the same manner as in Comparative Example 4, except that the raw materials and blending amounts of the thermally disintegrable layer were changed as shown in Table 2. Next, a mixed solvent of ethanol (EtOH) / water = 60% by mass / 40% by mass was added to CM8000 so that the solid content ratio was 20% by mass, and the mixture was thoroughly stirred while heating at 60°C to obtain a polyamide resin solution. The above polyamide resin solution was mixed with the raw materials for the resin layer in the amounts shown in Table 2 to obtain a resin composition. Next, the above resin composition was applied using an applicator onto the release-treated surface of a 75 μm thick PET liner having a release-treated surface so that the thickness after heating would be 15 μm, thereby creating a layer. A resin sheet (resin layer) was produced by heating in a thermostatic chamber at 100°C for 5 minutes. Next, a thermally disintegrable sheet having a layer structure of resin layer / thermally disintegrable layer / resin layer including a thermally disintegrable layer was produced by laminating a thermally disintegrable layer 11 and a resin layer 12 as shown in Figure 2. In addition, an evaluation specimen for evaluating the elastic modulus was produced in the same manner except that it did not contain an inorganic expanding agent, and used as the evaluation specimen.

[0138] The various raw materials shown in Tables 1 to 3 are as follows. CM-8000: Amilan CM8000, polyamide copolymer, manufactured by Toray Industries, Inc. UC-3510: Alphon UC3510, acrylic polymer, manufactured by Toagosei Co., Ltd. jER828: Bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation jER1256B40: Bisphenol A phenoxy resin, manufactured by Mitsubishi Chemical Corporation EX-141: Denacol EX-141, special epoxy compound, manufactured by Nagase ChemteX Corporation DGEBA: Bisphenol A epoxy resin, manufactured by Tokyo Chemical Industry Co., Ltd. Omicure DDA-50: Dicyandiamide, manufactured by HUNTSMAN DCMU: urea compound, manufactured by Hodogaya Chemical Co., Ltd. TETRAD-C: Multifunctional epoxy resin, manufactured by Mitsubishi Gas Chemical Company, Inc. DDM: Diaminodiphenylmethane, manufactured by Tokyo Chemical Industry Co., Ltd. M5: M5 Cab-o-sil, silica filler, manufactured by CABOT GG210-200N: Expanded graphite, manufactured by NeoGraf

[0139] 〔evaluation〕 (1) Elastic modulus (E') As an index of the strength and heat resistance of the matrix resin of the thermally disintegrable sheet and the disintegrability during thermal disintegration, the elastic modulus (E') at 25°C, 120°C and 250°C was calculated using the evaluation specimens of each of the Examples and Comparative Examples prepared above. A specimen for evaluation was cut into a width of 5 mm and a length of 50 mm. The release liner was peeled off, and the dynamic viscoelasticity was measured using a rheometer (product name "RSA G2", manufactured by TA Instruments) at a frequency of 1 Hz, a heating rate of 5°C / min, and a measurement temperature range of 0 to 250°C. The evaluation specimens of Examples 7 and 8 and Comparative Examples 4 and 5 were previously heat-cured at 100° C. for 60 minutes before evaluating the elastic modulus. In this manner, the elastic modulus E' was measured at each temperature. If the sample is destroyed during measurement or if the 4 The measurement was stopped when the elastic modulus was 1.0 × 10 4 Pa or less (<1.0×10 4 Pa).

[0140] (2) Adhesive strength The thermally disintegrable sheets of Examples 1 to 8 and Comparative Examples 2 to 4 were transferred from the release sheet to a 75 μm PET substrate and cut out to a width of 25 mm and a length of 12.5 mm to prepare test pieces for evaluating adhesive strength. The thermally disintegrable composition of Comparative Example 5 was applied to the PET substrate using an applicator to a thickness of 100 μm to form a thermally disintegrable layer, which was then cut out to a width of 20 mm and a length of 50 mm to prepare test pieces for evaluation. Next, the surface of the test piece with the thermally disintegrable layer was attached to aluminum plate A5052P. After 30 minutes, a tensile tester (trade name "RTG-1310", manufactured by A&D Co., Ltd.) was used to perform a 180°C peel test at a peel rate of 300 mm / min, and the adhesive strength [N / 20 mm] of the thermally disintegrable sheet was measured.

[0141] (3) Dismantling and expansion ratio (3-1) Dismantling Ease and Expansion Ratio (Examples 1-8, Comparative Examples 1-4) Test pieces for evaluating dismantling properties and expansion ratio were prepared by press molding using the thermally dismantlable sheets (thickness 100 μm) prepared in Examples 1 to 8 and Comparative Examples 2 to 4, CFRP prepregs, and thermally dismantlable sheets. A CFRP prepreg laminate (laminate 21) formed by laminating two layers of CFRP prepreg (3K, plain weave, thermosetting epoxy resin system) was cut out to a width of 50 mm and a length of 50 mm. A thermally disintegrable sheet was cut out to a width of 50 mm and a length of 50 mm. The cut-out laminate 21 and the thermally disintegrable sheet (thermal disintegrable layer 11) were used to produce laminate 300 as shown in FIG. 4. As shown in Figure 5, the laminate 300 was sandwiched between a 75 µm thick PET release liner 24 and a 2 mm thick aluminum plate 25. By heating at 150°C for 30 minutes while applying a pressure of 1 MPa, a bonded body (CFRP / thermally demolitionable sheet (thermally demolition layer) / CFRP) was obtained as a test piece for evaluating dismantling properties and expansion ratio. In Comparative Example 1, the test piece was made using only the CFRP prepreg (laminate 21) without using a thermally demolitionable sheet. The resulting test pieces were heated at 250°C for 10 minutes and allowed to cool to room temperature. The expansion ratio in the thickness direction of the thermally disintegrable sheet before and after heating was calculated as an index of dismantling ability using Equations 1 and 2. Dismantling ability was recorded as "Level 4" when the thermally disintegrable layers separated and the expansion ratio was 3.0 or more; "Level 3" when the thermally disintegrable layers separated and the expansion ratio was 2.0 or more but less than 3.0; "Level 2" when the thermally disintegrable layers did not separate and the expansion ratio was 1.0 or more; and "Level 1" when the thermally disintegrable layers did not separate and the expansion ratio was less than 1.0. Levels 3 and 4 are considered suitable for practical use.

[0142]

number

[0143]

number

[0144] (3-2) Dismantling and expansion rate (Comparative Example 5) Test specimens for evaluating dismantling properties and expansion ratio were prepared by press molding using CFRP prepreg and thermally decomposable composition. First, a CFRP prepreg laminate consisting of two layers of CFRP prepreg (3K, plain weave, thermosetting epoxy resin system) was cut into a width of 50 mm and a length of 50 mm to produce two laminates. As shown in FIG. 6, the thermally disintegratable composition of Comparative Example 5 was applied to the surface of one laminate 21 using an applicator to a thickness of 100 μm to form a layer 11′, and the other laminate 21 was placed on the formed layer 11′ to produce a laminate 300′ having the configuration shown in FIG. 7. 8, the laminate 300′ was sandwiched between a 75 μm thick PET release liner 24 and a 2 mm thick aluminum plate 25. By heating at 150°C for 30 minutes while applying a pressure of 1 MPa, a bonded body of Comparative Example 5 (CFRP / thermally dismantling sheet (thermally dismantling layer) / CFRP) was obtained as a test piece for evaluating dismantling ability and expansion coefficient.

[0145] The resulting bonded structure was heated at 250°C for 10 minutes and allowed to cool to room temperature. The expansion ratio in the thickness direction of the thermally disintegrable sheet before and after heating was calculated as an index of dismantling property using Equations 1 and 2. When the bonded structure delaminated between the thermally disintegrable layers and the expansion ratio was 3.0 or more, it was rated as "Lv4." When the bonded structure delaminated between the thermally disintegrable layers and the expansion ratio was 2.0 or more but less than 3.0, it was rated as "Lv3." When the bonded structure delaminated between the thermally disintegrable layers and the expansion ratio was 1.0 or more, it was rated as "Lv2." When the bonded structure delaminated between the thermally disintegrable layers and the expansion ratio was less than 1.0, it was rated as "Lv1." Levels 3 and 4 are considered suitable for practical use.

[0146] The evaluation results for Examples 1 to 8 and Comparative Examples 1 to 5 are shown in Tables 1 to 3 below.

[0147] [Table 1]

[0148] [Table 2]

[0149] [Table 3] [Explanation of symbols]

[0150] 100 Thermally decomposable sheet 11 Thermodegradable layer 11' layer 12 Resin layer 200 zygote 14 First member 15 Second member 21 Laminate 24 Release liner 25 Aluminum Plate 300, 300' laminate

Claims

1. A thermally disintegrable sheet having a thermally disintegrable layer, the thermally disintegratable layer contains a resin and an inorganic expanding agent, The content of the inorganic expanding agent relative to 100 parts by mass of the resin is 10 parts by mass or more, The adhesive strength of the thermally disintegratable sheet is 1.0 N / 20 mm or less. Thermally decomposable sheet.

2. The thermally disintegratable layer is Elastic modulus E' at 25°C ２５ is 10 ５ Pa or more 10 １０ Pa or less, Elastic modulus E' at 120°C １２０ is 10 ４ Pa or more 10 ８ Pa or less, Elastic modulus E' at 250°C ２５０ is 10 ５ Pa or less, The thermally disintegrable sheet according to claim 1.

3. 2. The thermally disintegrable sheet according to claim 1, which has an expansion ratio in the thickness direction of 2.0 times or more after heating at 250°C for 10 minutes.

4. 2. The thermally disintegrable sheet according to claim 1, wherein the inorganic expanding agent is expanded graphite or a silicate.

5. The thermally disintegrable sheet according to claim 1 , wherein the thermally disintegrable layer further comprises a filler.

6. The thermally disintegrable sheet according to claim 5 , wherein the resin comprises at least one selected from the group consisting of polyamide resin, acrylic rubber, and epoxy resin.

7. The thermally disintegrable sheet according to claim 5 , wherein the resin comprises an epoxy-modified resin.

8. The thermally disintegrable sheet according to claim 1 , further comprising a resin layer.

9. A thermally disintegrable sheet with a release liner, comprising the thermally disintegrable sheet according to claim 1 and a release sheet.

10. A laminate in which the thermally disintegrable sheet according to any one of claims 1 to 8 is laminated on a resin material.

11. A bonded body obtained by bonding the thermally disintegrable sheet according to any one of claims 1 to 8 and a resin material.

12. the resin material is a first member, The joined body according to claim 11 , wherein the first member and the second member are joined by the thermally disintegrable sheet.

13. The assembly of claim 12 , wherein the resin material comprises a thermosetting resin.

14. A method for producing a bonded body using the thermally disintegrable sheet according to any one of claims 1 to 8.

15. a lamination step of laminating the thermally disintegratable sheet and a resin material; a fusion step of fusing the thermally disintegratable layer and the resin material, The method for producing the bonded body according to claim 13 .

16. a lamination step of laminating the thermally disintegrable sheet and a substrate; an impregnation step of impregnating the substrate with a resin composition; a curing step of curing the resin composition to form a resin material; Equipped with The method for producing the bonded body according to claim 13 .

17. 12. A method for dismantling a bonded body according to claim 11, comprising the step of heating at least a portion of the bonded body to destroy the thermally disintegrable layer.

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