Adhesive body and method for producing the same

Abstract

An aspect of the present invention relates to a bonded object or a method for producing the bonded object, the bonded object comprising substrates bonded to each other by an adhesive layer obtained from a fluororubber composition comprising at least one fluororubber selected from among fluoroelastomers (FKM) and perfluoroelastomers (FFKM) and having a Mooney viscosity (ML1+10), as measured at 121°C in accordance with ASTM D 1646, of 80-115.

Description

[Technical field]

[0001] One embodiment of the present invention relates to an adhesive body or a method for producing an adhesive body. [Background technology]

[0002] Substrates such as nonwoven fabrics, woven fabrics, fibers, porous membranes, and films may be used alone or in combination with a plurality of the same substrates or with other substrates.

[0003] When substrates are laminated in this manner, a method is usually used in which an adhesive is used to bond the substrates together by reacting components contained in the adhesive or volatilizing the solvent, or the adhesive layer or the substrate itself is melted and thermally fused to bond the substrates together (e.g., Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-283517 A Summary of the Invention [Problem to be solved by the invention]

[0005] The method of bonding substrates together using the adhesive has the advantage that the substrates can be bonded together easily, but the obtained bonded body may have problems with the heat resistance of the adhesive part, or foreign matter may be mixed in or contamination may occur at the adhesive part, leaving room for improvement in this regard.

[0006] In addition, the method of bonding substrates together by heat fusion has the advantage that an adhesive with high adhesive strength can be obtained, but the freedom of selection of the substrate is limited in terms of heat resistance, and there is room for improvement in that the shape and physical properties of the substrates before fusion, specifically, the shape of voids and the like that the substrates before fusion had, the function of the functional material contained in the substrates before fusion, and the functions of the substrates before fusion due to treatment such as surface treatment, are impaired (lost). Furthermore, the method of bonding substrates together by thermal fusion also leaves room for improvement in terms of energy costs.

[0007] One embodiment of the present invention provides an adhesive structure in which substrates are bonded together with sufficient adhesive strength using a fluororubber, without impairing the physical properties, shape, function, etc., of the substrates before bonding. [Means for solving the problem]

[0008] As a result of intensive research by the present inventors to solve the above problems, they found that the above problems can be solved by the following configuration examples, and completed the present invention. A configuration example of the present invention is as follows.

[0009] [1] The substrates are An adherend formed via an adhesive layer made of a fluororubber composition containing at least one fluororubber selected from fluoroelastomers (FKM) and perfluoroelastomers (FFKM) and having a Mooney viscosity (ML1+10) of 80 to 115 at 121°C as measured in accordance with ASTM D 1646.

[0010] [2] The fluororubber composition is A fluororubber (A1) having a Mooney viscosity (ML1+10) of 40 to 150 at 121°C as measured in accordance with ASTM D 1646; Fluororubber (A2) having a Mooney viscosity (ML1+10) of 10 or more and less than 40 at 121°C as measured in accordance with ASTM D 1646; The adhesive according to [1],

[0011] [3] The adhesive body according to [1] or [2], wherein the fluororubber contains a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene polymer.

[0012] [4] The bonded body according to any one of [1] to [3], wherein the bonded body is bonded in the presence of liquid or gaseous carbon dioxide.

[0013] [5] The bonded body according to any one of [1] to [4], wherein the bonded body is bonded at a temperature lower than the melting temperature of the fluororubber.

[0014] [6] A method for producing an adhesive body, comprising the steps of: Providing a structure having an adhesive disposed between substrates; bonding the structure in the presence of liquid or gaseous carbon dioxide; Including, The adhesive is an adhesive obtained from a fluororubber composition having a Mooney viscosity (ML1+10) of 80 to 115 at 121°C measured in accordance with ASTM D 1646. A method for producing an adhesive body.

[0015] [7] placing the structure in a pressure vessel; introducing carbon dioxide into the pressure vessel; The method for producing an adhesive body according to [6], further comprising:

[0016] [8] The step of introducing carbon dioxide into the pressure vessel comprises: A process of introducing liquid or gaseous carbon dioxide into a pressure vessel so that the pressure in the pressure vessel is 3 MPa or more. A method for producing the adhesive structure described in [7].

[0017] [9] The method for producing an adhesive body according to any one of [6] to [8], wherein the fluororubber composition contains at least one kind of fluororubber selected from a fluoroelastomer (FKM) and a perfluoroelastomer (FFKM).

[0018]

[10] The fluororubber composition, A fluororubber (A1) having a Mooney viscosity (ML1+10) of 40 to 150 at 121°C as measured in accordance with ASTM D 1646; Fluororubber (A2) having a Mooney viscosity (ML1+10) of 10 or more and less than 40 at 121°C as measured in accordance with ASTM D 1646; The method for producing an adhesive body according to any one of [6] to [9], comprising:

[0019]

[11] The method for producing an adhesive body according to any one of [6] to

[10] , wherein the fluororubber composition contains a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene polymer.

[0020]

[12] The method for producing an adherend according to any one of [6] to

[11] , wherein the adhesive is the fluororubber composition in a liquid or paste form, a dried product of the fluororubber composition in a liquid or paste form, or a fiber, nonwoven fabric or film obtained from the fluororubber composition.

[0021]

[13] The adhesive, A step of spinning the fluororubber composition; and Step B of crosslinking the fibers obtained in step A The fluororubber fiber or fluororubber nonwoven fabric is obtained by a method comprising the steps of: The method for producing the bonded body according to any one of [6] to

[12] .

[0022]

[14] The method for producing an adhesive body according to any one of [6] to

[13] , wherein at least one of the substrates is a nonwoven fabric, a woven fabric, a porous membrane or a fiber.

[15] The substrate is selected from a nonwoven fabric, a woven fabric, and a porous membrane; The adhesive is a fiber or a nonwoven fabric obtained from the fluororubber composition. The method for producing the bonded body according to any one of [6] to

[14] . Effect of the Invention

[0023] According to one embodiment of the present invention, it is possible to provide an adhesive body in which substrates are bonded together using fluororubber with sufficient adhesive strength (e.g., peel strength of 0.3 N / 10 mm or more) without impairing the physical properties, shape, function, etc., of the substrates before bonding. Furthermore, according to one embodiment of the present invention, there is a high degree of freedom in the selection of the substrate, so that a bonded body can be obtained using any desired substrate without impairing its physical properties, shape, function, etc., and the adhesive portion (adhesive layer) has excellent chemical resistance, and an adhesive body can be obtained in which foreign matter is less likely to enter or become contaminated through the adhesive portion (adhesive layer). According to one embodiment of the present invention, since the adhesive body can be formed without applying heat from the outside, the adhesive body can be obtained at low energy cost and through a simplified process, and further, the obtained adhesive body has the advantage that it is easy to perform secondary processing. Furthermore, according to one embodiment of the present invention, multiple adhesive bodies can be formed in a single process, so that even if multiple adhesive bodies are required, the desired adhesive bodies can be obtained at low energy costs and through a simplified process. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a plan view showing an outline of a laminate of a substrate and an adhesive used in Example 9. As shown in FIG. [Diagram 2] FIG. 2 is a front view showing the outline of the state in which the laminate of FIG. 1 is spirally wound around a rod or a cylindrical member (the state of the bonded body obtained in Example 9). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] ≪Adhesive body≫ An adherend according to one embodiment of the present invention (hereinafter also referred to as "the adherend") is an adherend in which substrates are adhered to each other via an adhesive layer obtained from a fluororubber composition containing at least one kind of fluororubber selected from fluoroelastomers (FKM) and perfluoroelastomers (FFKM) and having a Mooney viscosity of 80 to 115. Hereinafter, the term "Mooney viscosity" in this specification refers to the Mooney viscosity (ML1+10) at 121°C measured in accordance with ASTM D1646.

[0026] This adhesive may be an adhesive (hereinafter also referred to as "adhesive (I)") different from a so-called pressure-bonded body in which substrates are bonded together without being pressed, or may be a so-called pressure-bonded body (hereinafter also referred to as "adhesive (II)") in which substrates are bonded together by pressing. For example, the bonded body (I) obtained by the method (I) described below usually has a strength of several hundred gf / cm in the lamination direction of the substrates during bonding. 2 When bonding, only a pressure (surface pressure) of about 10 kgf / cm is applied in the lamination direction of the base materials. 2 This is different from a crimped body that is subjected to a pressure of a certain degree or more. The present adhesive product is preferably the above-mentioned adhesive product (I) in that it forms an adhesive product in which the substrates are sufficiently bonded to each other without substantially impairing the shapes of the substrates before bonding (e.g., voids and fiber shapes of nonwoven fabrics, etc.), and is preferably the above-mentioned adhesive product (II) in that it provides superior adhesive strength between the substrates.

[0027] The present bonded body is preferably a bonded body that is bonded in the presence of liquid or gaseous carbon dioxide. By bonding in the presence of liquid or gaseous carbon dioxide, at least a portion of the fluororubber is plasticized by the carbon dioxide, and the substrates can be bonded and joined while being interlocked with each other and the shape is fixed due to the anchor effect, etc., and an adherend can be obtained without applying heat from the outside or pressing the substrates together while maintaining the shape and physical properties, etc., of the substrates before bonding. For this reason, an adherend bonded in the presence of liquid or gaseous carbon dioxide is preferable because it is an adherend in which the substrates are bonded with sufficient adhesive strength while maintaining the shape and physical properties, etc., of the substrates before bonding.

[0028] For the same reasons as above, the adhesive (II) is preferably an adhesive that is compressed in the presence of liquid or gaseous carbon dioxide, particularly in the presence of liquid, gas-liquid mixed, or near-liquid carbon dioxide. In this specification, "carbon dioxide in a state close to liquid" specifically refers to carbon dioxide in a state in which the density is 0.4 g / mL or more (about half the density of liquid carbon dioxide).

[0029] The present bonded body is preferably bonded at a temperature below the melting temperature of the fluororubber, preferably at a temperature of about 50° C. or less, and more preferably without applying heat from the outside. In this case, various substrates can be used as the substrate in this adhesive body, and even if a substrate that has been subjected to a functionalization treatment such as a conventionally known surface treatment such as hydrophilization treatment is used, the function is not impaired, so the substrate can be selected with a high degree of freedom. In particular, the substrate can be made to have the characteristics of the substrate (e.g., function, voids in the nonwoven fabric, fiber shape) intact, and when this adhesive body is made to have a functional material such as the following, even if the functional material has poor heat resistance, the adhesive body can have the functions, properties, etc. of the functional material.

[0030] The shape and size of the present adhesive body are not particularly limited and may be appropriately selected depending on the desired application, etc. Examples of the shape of the present adhesive body include a laminate shape, a bag shape, a ring shape, a spiral shape, and a tube shape (cylindrical shape). The thickness of the adhesive body is not particularly limited and may be appropriately selected depending on the application, but in the case of a laminated adhesive body using a nonwoven fabric or a porous membrane as the substrate, the thickness is usually 10 μm or more, preferably 50 μm or more, and usually 30 mm or less, preferably 25 mm or less.

[0031] The adhesive can be suitably used in applications where substrates containing resins, carbon materials, glass, metals, etc. have been used, and is particularly suitable for use in the medical field, electrical equipment field, semiconductor field, etc., and specifically, is suitable for use as filters, various separators, clothing, etc.

[0032] The adhesive body may contain one or more functional materials required for a desired application, such as foodstuffs, drugs (medicinal, agricultural, industrial), dyes, adsorbents, deodorants, fragrances, insect repellents, electronic device materials, enzymes, and catalysts. Furthermore, when the present adhesive contains, for example, a drug or the like, it can also be an adhesive with controlled sustained release.

[0033] <Adhesive layer> The adhesive layer is an adhesive layer obtained from the fluororubber composition. The adhesive layer in the adhesive body refers to a member that bonds the substrates together, and is not necessarily limited to a layer (film-like) layer, but includes a layer that exists only between fibers (a member that connects the fibers together).

[0034] The thickness of the adhesive layer varies depending on the adhesive used in producing the bonded body, but is usually 1 μm or more, preferably 3 μm or more, and usually 1 mm or less, preferably 200 μm or less.

[0035] [Fluororubber composition] The fluororubber composition that is the raw material of the adhesive layer contains at least one type of fluororubber selected from fluoroelastomers (FKM) and perfluoroelastomers (FFKM), and has a Mooney viscosity of 80 to 115. The fluororubber composition in the adhesive used in the present method described below preferably contains at least one type of fluororubber selected from fluoroelastomers (FKM) and perfluoroelastomers (FFKM).

[0036] The fluororubber composition has a Mooney viscosity of 80 or more, preferably 85 or more, more preferably 90 or more, and 115 or less, preferably 110 or less. By using an adhesive layer or adhesive obtained from a fluororubber composition having a Mooney viscosity within the above range, an adherend in which substrates are adhered to each other with sufficient adhesive strength can be easily obtained. In particular, when bonding is carried out in the presence of liquid or gaseous carbon dioxide during the production of an adhesive, it is believed that, as described above, at least a portion of the fluororubber is plasticized by the carbon dioxide, and due to an anchor effect or the like, the substrates are interlocked with each other, and the shape is fixed and the substrates are bonded and joined. It is believed that a fluororubber composition having a Mooney viscosity within the above range has high affinity with carbon dioxide and is more likely to be plasticized by carbon dioxide, and therefore, by using this composition, it is believed that an adhesive in which substrates are bonded to each other with sufficient adhesive strength can be easily obtained. Furthermore, a fluororubber composition having a Mooney viscosity within the above range is easy to spin, and after spinning, the shape of the obtained fluororubber fiber (nonwoven fabric) is unlikely to change, and a fiber (nonwoven fabric) having a desired shape (average fiber diameter) can be easily formed. Therefore, when the fluororubber fiber or fluororubber nonwoven fabric is used as an adhesive for producing an adherend, the fiber or nonwoven fabric can be easily formed. In one embodiment of the present invention, the fluororubber (fluororubber composition) may be crosslinked, and the Mooney viscosity in this specification refers to the Mooney viscosity before the fluororubber (fluororubber composition) is crosslinked.

[0037] [Fluororubber] The fluororubber is at least one selected from fluoroelastomers (FKM) and perfluoroelastomers (FFKM). Among these, FKM is preferred because it is considered to be easily plasticized by carbon dioxide. In addition, FKM has excellent chemical resistance and heat resistance, and also has excellent resistance to stains, dirt, oxidation, and ultraviolet rays. The fluororubber contained in the fluororubber composition may be one type or two or more types.

[0038] As the fluororubber used in the fluororubber composition, it is preferable to use a fluororubber that gives a Mooney viscosity of the resulting fluororubber composition within the above range. As the fluororubber, one or more kinds of fluororubbers having a Mooney viscosity in the above range may be used, but it is preferable to contain a fluororubber (A1) having a Mooney viscosity of 40 to 150 and a fluororubber (A2) having a Mooney viscosity of 10 or more and less than 40, from the viewpoints that a fluororubber composition having a Mooney viscosity in the above range can be easily prepared, and when a fluororubber fiber or a fluororubber nonwoven fabric is used as an adhesive used in producing an adherend, spinning is easy, the shape of the obtained fluororubber fiber (nonwoven fabric) is unlikely to change after spinning, and fibers (nonwoven fabric) having the desired shape (average fiber diameter) can be easily formed.

[0039] The weight average molecular weight of the fluororubber as measured by gel permeation chromatography is preferably 1×10 to 50% by weight, from the viewpoints of excellent solubility in a solvent when a liquid or paste-like fluororubber composition is prepared, and of easy formation of an adhesive layer having excellent mechanical strength. 3 More preferably, 1×10 4 or more, preferably 5×10 7 Less than or equal to 1×10 7 The following is the result.

[0040] The fluorine content in the fluororubber is preferably 55% by mass or more, more preferably 62% by mass or more, particularly preferably 64% by mass or more, and is preferably 80% by mass or less, more preferably 78% by mass or less. When the fluorine content is within the above range, when a fluororubber fiber or a fluororubber nonwoven fabric is used as an adhesive for producing a bonded body, the fiber can be easily spun, and an adhesive layer having excellent chemical resistance can be easily formed. The fluorine content can be measured or calculated by solid-state nuclear magnetic resonance (NMR) or mass spectrometry (MS spectrometry), or the like.

[0041] The content of the fluororubber in the adhesive layer is preferably 20% by mass or more, more preferably 30% by mass or more, and particularly preferably 50% by mass or more. The upper limit of the content is not particularly limited, but may be 100% by mass when the adhesive layer does not contain the below-mentioned filler. The content of the fluororubber in the fluororubber composition is, for example, 5% by mass or more, preferably 10% by mass or more, and for example, 100% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less. When the content of the fluororubber is within the above range, an adhesive layer in which the physical properties of the fluororubber, such as chemical resistance and heat resistance, are more fully exhibited can be easily obtained.

[0042] ·FFKM The FFKM is not particularly limited, but examples thereof include polymers that do not contain hydrogen atoms (carbon-hydrogen bonds) in the polymer main chain (excluding the terminals). Specifically, examples thereof include tetrafluoroethylene (TFE)-perfluorovinyl ether copolymers, and copolymers that contain structural units derived from TFE and structural units derived from perfluorovinyl ether and, if necessary, structural units derived from a cross-linking site-containing monomer are preferred.

[0043] Suitable examples of the perfluorovinyl ether include perfluoro(alkyl vinyl ether) and perfluoro(alkoxyalkyl vinyl ether).

[0044] The perfluoro(alkyl vinyl ether) may be a compound in which the alkyl group has, for example, 1 to 10 carbon atoms. Specific examples include perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), and perfluoro(propyl vinyl ether), and preferably perfluoro(methyl vinyl ether).

[0045] The perfluoro(alkoxyalkyl vinyl ether) may be a vinyl ether group (CF 2 Specific examples of the compound include compounds having a carbon number of 3 to 15 in the group bonded to the group (=CFO-). CF 2 =CFOCF 2 CF(CF 3 )OC n F 2n+1 , CF 2 =CFO(CF 2 ) 3 O.C. n F 2n+1 , CF 2 =CFOCF 2 CF(CF 3 )O(CF 2 O) m C n F 2n+1 , CF 2 =CFO(CF 2 ) 2 O.C. n F 2n+1 Examples include: In these formulas, n is, independently, for example, 1 to 5, and m is, for example, 1 to 3.

[0046] The FFKM can be provided with crosslinkability by including a structural unit derived from a crosslinking site-containing monomer. The crosslinking site means a site capable of undergoing a crosslinking reaction, and examples of such sites include a nitrile group, a halogen group (e.g., an I group, a Br group), and a perfluorophenyl group.

[0047] Crosslinking site having a nitrile group as a crosslinking site Contains Examples of the monomer include nitrile group-containing perfluorovinyl ethers, specifically, CF 2 =CFO(CF 2 ) n OCF(CF 3 )CN (n is, for example, 2 to 4); CF 2 =CFO(CF 2 ) n CN (n is, for example, 2 to 12), CF 2 =CFO[CF 2 CF(CF 3 )O] m (CF 2 ) n CN (n is, for example, 1 to 4, m is, for example, 1 to 5), CF 2 =CFO[CF 2 CF(CF 3 )O] n CF 2 CF(CF 3 )CN (n is, for example, 0 to 4) etc.

[0048] Examples of crosslinking site-containing monomers having a halogen group as a crosslinking site include halogen group-containing perfluorovinyl ethers, and specific examples thereof include compounds in which the nitrile group in the specific examples of the nitrile group-containing perfluorovinyl ethers described above is replaced with a halogen group.

[0049] In FFKM, the content of constituent units derived from TFE is preferably 50.0 to 79.9 mol %, the content of constituent units derived from perfluorovinyl ether is preferably 20.0 to 46.9 mol %, and the content of constituent units derived from crosslinking site-containing monomers is preferably 0.1 to 2.0 mol %.

[0050] ·FKM The FKM may be any fluoroelastomer other than the FFKM, and is not particularly limited, but specific examples include vinylidene fluoride-hexafluoropropylene polymers; vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene polymers; tetrafluoroethylene-propylene polymers; vinylidene fluoride-propylene-tetrafluoroethylene polymers; ethylene-tetrafluoroethylene-perfluoromethylvinyl ether polymers; vinylidene fluoride-tetrafluoroethylene-perfluoromethylvinyl ether polymers, and vinylidene fluoride-perfluoromethylvinyl ether polymers. Among these, ternary polymers are preferred from the viewpoint of excellent heat resistance, chemical resistance, etc., and vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene polymers are more preferred. In order to impart crosslinkability to the FKM, the FKM may contain a constituent unit derived from a crosslinking site-containing monomer, as in the section on FFKM above.

[0051] [Additives] In addition to the fluororubber, the fluororubber composition may contain conventionally known additives, if necessary, within the range that does not impair the effects of the present invention. Examples of the additives include polymers other than the fluororubber (e.g., fluororesin), crosslinking agents, co-crosslinking agents, antioxidants, antioxidants, vulcanization accelerators, stabilizers, silane coupling agents, fillers (reinforcing agents), plasticizers, flame retardants, waxes, lubricants, solvents, surfactants, dispersants, charge control agents, viscosity control agents, and fiber-forming agents. The additives may be used alone or in combination of two or more.

[0052] When the other polymer is used as the additive, the content of the fluororubber is 50% by mass or more relative to 100% by mass of the total of the fluororubber and the other polymer in the fluororubber composition.

[0053] The crosslinking agent may be appropriately selected depending on the fluororubber used. For example, when FKM is used, examples of the crosslinking agent include peroxide-based crosslinking agents, polyamine-based crosslinking agents, and polyol-based crosslinking agents. When FFKM is used, examples of the crosslinking agent include peroxide-based crosslinking agents, bisphenol-based crosslinking agents, triazine-based crosslinking agents, oxazole-based crosslinking agents, imidazole-based crosslinking agents, and thiazole-based crosslinking agents. When a crosslinking agent is used, the amount of the crosslinking agent used per 100 parts by mass of the fluororubber is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, and preferably 30 parts by mass or less, more preferably 10 parts by mass or less.

[0054] Examples of peroxide-based crosslinking agents include 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, di-t-butyl peroxide, t-butyldicumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-(t-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, t-butylperoxyisopropyl carbonate, and p-chlorobenzoyl peroxide.

[0055] As the co-crosslinking agent, a conventionally known co-crosslinking agent (crosslinking assistant) can be used. Examples of the co-crosslinking agent include compounds (polyfunctional monomers) capable of co-crosslinking by radicals, such as triallyl isocyanurate, triallyl cyanurate, triallyl formal, triallyl trimellitate, N,N'-m-phenylene bismaleimide, dipropargyl terephthalate, diallyl phthalate, and tetraallyl terephthalamide. Among these, it is preferable to include triallyl isocyanurate in terms of reactivity and the heat resistance of the resulting adhesive layer. When a co-crosslinking agent is used, the amount of the co-crosslinking agent used per 100 parts by mass of the fluororubber is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 30 parts by mass or less, more preferably 10 parts by mass or less.

[0056] Examples of the filler include functional fillers (e.g., thermally conductive particles, electrically conductive particles, insulating particles, reinforcing fibers), and specific examples of the filler include carbon materials (e.g., carbon black, nanocarbon, carbon nanotubes, graphite), silica, alumina, zinc oxide, titanium dioxide, clay, talc, diatomaceous earth, barium sulfate, silicate compounds (silicates, etc.), calcium carbonate, magnesium carbonate, calcium oxide, mica, aluminum hydroxide, metal (e.g., silver) particles, and resin fine particles. The shape of the filler is not particularly limited, and examples thereof include particles and fibers.

[0057] When the fluororubber composition contains the filler, the content of the filler in the fluororubber composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, and is preferably 80% by mass or less, more preferably 70% by mass or less, from the viewpoints that the physical properties of the fluororubber such as chemical resistance and heat resistance are exhibited and that the physical properties of the filler are fully exhibited.

[0058] The solvent is not particularly limited as long as it can dissolve or disperse the fluororubber, and examples thereof include water, dimethylacetamide, dimethylformamide, tetrahydrofuran, methylpyrrolidone, xylene, acetone, methyl ethyl ketone, chloroform, ethylbenzene, cyclohexane, benzene, sulfolane, methanol, ethanol, phenol, pyridine, propylene carbonate, acetonitrile, trichloroethane, hexafluoroisopropanol, diethyl ether, and fluorine-based solvents. The amount of the solvent used is, for example, 0 mass % or more, preferably 10 mass % or more, more preferably 20 mass % or more, and preferably 90 mass % or less, more preferably 80 mass % or less, relative to 100 mass % of the fluororubber composition.

[0059] <Base material> The number of the substrates may be one or more. The number of substrates used in the bonded body (II) is preferably two or more. Examples of the case where one substrate is used include a case where both ends of the substrate are in contact with each other (e.g., a sheet-like substrate is rolled so that both ends are in contact with each other) and both ends of the substrate are bonded with an adhesive layer, and a laminate having adhesive 2 disposed on a long substrate 1 as shown in FIG. 1 is spirally wound around a rod or tubular member 4 as shown in FIG. 2 and bonded with adhesive 2, and for example, a ring-shaped or tubular (cylindrical) bonded body is obtained. When two or more substrates are used, two or more substrates having different materials, shapes, etc. may be used, or two or more substrates having the same material, shape, etc. may be used.

[0060] The substrate is not particularly limited, and examples thereof include substrates containing at least one selected from the group consisting of resins, carbon materials, glass, and metals. As the substrate, it is preferable to use at least one selected from a nonwoven fabric, a woven fabric, a porous membrane, and a fiber, from the viewpoint that an adhesive body having a desired shape in which substrates are bonded to each other with sufficient adhesive strength can be easily obtained, and it is more preferable to use at least one selected from a nonwoven fabric, a woven fabric, and a porous membrane.

[0061] 〔resin〕 The resin is not particularly limited, but examples thereof include fluororesins, engineering plastics, and other plastics. Among these, fluororesins and engineering plastics are preferred.

[0062] [Fluorine resin] The fluororesin is not particularly limited, and conventionally known fluororesins can be used. The fluororubber contained in the fluororubber composition and the fluororesin constituting the substrate may be the same or different, but are preferably different, and it is more preferable that the crystallinity of the fluororesin constituting the substrate is higher than the crystallinity of the fluororubber contained in the fluororubber composition.

[0063] Specific examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE), fluoroethylene-vinyl ether copolymer (FEVE), poly(chlorotrifluoroethylene) (PCTFE), ethylene-chlorotrifluoroethylene-copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), vinylidene fluoride-hexafluoropropylene copolymer (VDF-HFP copolymer), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer (VDF-HFP-TFE copolymer). Among these, PTFE and PFA are preferred.

[0064] [Engineering plastics] The engineering plastic is not particularly limited, and conventionally known engineering plastics can be used. Specific examples thereof include polyphenylene sulfide resins (PPS), polysulfone resins, polyethersulfone resins, polyetheretherketone resins (PEEK), polyarylate resins, liquid crystal polymers, aromatic polyester resins, polyimide resins, polyamideimide resins, polyetherimide resins, aramid resins, polycarbonate resins, polyacetal resins, polyethylene terephthalate (PET), polybutylene terephthalate (PPE), and the like. Examples of suitable resins include polyester resins such as polycyclohexylene dimethyl terephthalate (PBT) and polycyclohexylene dimethyl terephthalate (PCT), polyphenylene ether resins, polyphenylene oxide resins, polyamide resins such as nylon 6, nylon 66 and aromatic polyamide, (meth)acrylic polymers, vinyl chloride polymers, vinylidene chloride polymers, polybenzazole resins (e.g. polybenzimidazole (PBI)), polyethylene (e.g. ultra-high molecular weight polyethylene), polypropylene (e.g. ultra-high molecular weight polypropylene), and other olefin resins.

[0065] [Other plastics] The other plastic is not particularly limited as long as it is a resin other than a fluorine-based resin or an engineering plastic, and a conventionally known plastic can be used. do. Specific examples include thermosetting resins such as polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile-butadiene-styrene resin (ABS), polymethyl methacrylate resin (PMMA), phenol resin (including straight phenol resin and various modified phenol resins), melamine resin, and epoxy resin.

[0066] The base material containing the resin may contain other components such as fibers, such as carbon fibers or glass fibers, and the additives described in the section on the adhesive layer.

[0067] Examples of the form of the substrate containing the resin include fibers, porous membranes (including stretched porous membranes), nonwoven fabrics, woven fabrics, and films. In addition, when a film containing a resin is used as the substrate, it is preferable to use a film whose surface in contact with the adhesive has been roughened by a conventionally known method, from the viewpoint that an adhesive body in which substrates are bonded to each other with sufficient adhesive strength can be obtained, etc. In addition, since it is not easy to bond resin-containing films to each other, when a film containing a resin is used as the substrate, it is preferable that the substrate bonded to the film is a substrate through which carbon dioxide can pass, for example, a fiber, a porous membrane, a nonwoven fabric, or a woven fabric.

[0068] [Carbon materials] Examples of the substrate containing a carbon material include substrates containing carbon fibers, carbon nanotubes, and graphite sheets. The shape of the substrate containing carbon fibers is not particularly limited, and examples of the substrate include fibers, filaments, cloth, felt, mats, papers, and prepregs.

[0069] [Glass] Examples of the substrate containing glass include glass fiber, glass woven fabric, and glass nonwoven fabric. Specific examples of these include glass cloth, glass paper, glass mat, glass felt, and substrates having the above-mentioned resin on the surface thereof.

[0070] [metal] Examples of the substrate containing a metal include woven metal fabric, nonwoven metal fabric, and metal fiber (including wool-like metal). The substrate containing a metal may also be a substrate in which a support such as a fiber, a porous membrane, a nonwoven fabric, or a woven fabric is treated with a metal (e.g., a substrate in which a support is plated or a substrate in which a metal is vapor-deposited on a support). Examples of the metal include stainless steel, aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, copper, copper alloys, gold, gold alloys, silver, silver alloys, tantalum, tantalum alloys, chromium, chromium alloys, molybdenum, molybdenum alloys, tungsten, and tungsten alloys.

[0071] As the substrate, a substrate made of a fluororesin is preferable, and a substrate made of PTFE, PFA, or the like is more preferable, because the substrate has excellent mechanical strength, heat resistance, chemical resistance, weather resistance, and electrical insulation, and an adhesive can be easily obtained in which all of the components constituting the adhesive are fluorine components. Incidentally, since fluorine components are non-adhesive and have a small coefficient of friction, it has not been possible to obtain an adherend having a desired shape in which substrates are bonded together with sufficient adhesive strength using an adhesive in which all of the components constituting the adhesive are fluorine components. However, according to one embodiment of the present invention, even with an adhesive made of such a fluorine component, it is possible to easily obtain an adherend having a desired shape in which substrates are bonded together with sufficient adhesive strength.

[0072] The nonwoven fabric, woven fabric, porous membrane, fiber (tube), and film (sheet) are not particularly limited, and conventionally known nonwoven fabrics, woven fabrics, porous membranes, fibers (tubes), and films (sheets) can be used.

[0073] The substrate may be a substrate that has been subjected to a functionalization treatment such as a conventionally known surface treatment such as a hydrophilization treatment. According to one embodiment of the present invention, even if a substrate that has been subjected to such a functionalization treatment is used, an adhesive body in which the function is not impaired can be obtained.

[0074] The average fiber diameter of the fibers constituting the nonwoven fabric or woven fabric, or the fibers serving as the base material, is preferably 0.01 μm or more, more preferably 0.1 μm or more, even more preferably 0.5 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 20 μm or less. When the average fiber diameter is within the above range, the mechanical strength is excellent. , ten Therefore, a bonded body having a desired shape in which the substrates are bonded together with sufficient adhesive strength can be easily obtained.

[0075] The average fiber diameter in this specification is an average value calculated based on the measurement results by observing the fiber (group) to be measured with a scanning electron microscope (SEM) (magnification: for example, 2000 times), randomly selecting 20 fibers from the obtained SEM image, and measuring the fiber diameter (long diameter) of each of these fibers.

[0076] The fiber diameter variation coefficient of the fibers constituting the nonwoven fabric or woven fabric, or the fibers serving as the base material, calculated by the following formula, is preferably 0.7 or less, more preferably 0.01 to 0.5. When the fiber diameter variation coefficient is within the above range, the fiber diameter becomes uniform, and the mechanical strength is excellent. , ten Therefore, a bonded body having a desired shape in which the substrates are bonded together with sufficient adhesive strength can be easily obtained. Coefficient of variation of fiber diameter = standard deviation / average fiber diameter (Note that the "standard deviation" refers to the standard deviation of the fiber diameters of the 20 fibers.)

[0077] The fiber length of the fibers constituting the nonwoven fabric or woven fabric and the fibers serving as the base material is not particularly limited, but is preferably 0.5 mm or more, more preferably 1 mm or more, and is preferably 100 mm or less, more preferably 50 mm or less.

[0078] The stretched porous membrane is not particularly limited, and may be a uniaxially stretched porous membrane or a biaxially stretched porous membrane.

[0079] The porosity of the nonwoven fabric, woven fabric or porous membrane is not particularly limited, but is, for example, 0.1 vol. % or more, preferably 30 vol. % or more, and is, for example, 95 vol. % or less, preferably 90 vol. % or less. The porosity in this specification can be calculated from the difference between the theoretical volume calculated assuming no voids based on the specific gravity of the material constituting the nonwoven fabric, woven fabric or porous membrane and the actual measured mass of the nonwoven fabric, woven fabric or porous membrane, and the actual volume calculated by measuring the dimensions of the nonwoven fabric, woven fabric or porous membrane, using the following formula. Porosity (volume%) = (1-(theoretical volume / measured volume)) x 100

[0080] The weight of the nonwoven fabric, woven fabric or porous membrane is preferably 100 g / m 2 or less, more preferably 1 to 80 g / m 2 It is.

[0081] The thickness of the nonwoven fabric, woven fabric, porous membrane, or film (sheet) is usually 5 μm or more, preferably 10 μm or more, and usually 1 mm or less, preferably 500 μm or less. The nonwoven fabric, woven fabric, porous membrane, and film (sheet) may be composed of a single layer, or may be composed of two or more identical or different layers.

[0082] <Method of manufacturing adhesive body> The method for producing a bonded body according to one embodiment of the present invention (hereinafter also referred to as "this method") is as follows: Step I of preparing a structure having an adhesive disposed between substrates; Step II of bonding the structure in the presence of liquid or gaseous carbon dioxide; Including, The adhesive is an adhesive obtained from a fluororubber composition having a Mooney viscosity ML1+10 of 80 to 115 at 121° C. as measured in accordance with ASTM D 1646. According to this method, the present bonded body can be produced.

[0083] A specific example of the method for producing the bonded body (I) according to one embodiment of the present method (hereinafter also referred to as "the present method (I)") is as follows: Between steps I and II in the method, A step 1 of placing the structure obtained in the step I in a pressure vessel; Step 2 of introducing carbon dioxide into the pressure vessel having the structure obtained in step 1; Includes. Incidentally, the step 2 may be carried out as substantially the same step as the step II.

[0084] A specific example of the method for producing the bonded body (II) according to one embodiment of the present method (hereinafter also referred to as "the present method (II)") is as follows: The step II includes a step 4 of pressing (bonding by pressing) the substrate.

[0085] The substrate is preferably made of a fluororesin. In this case, the present method can be said to be a novel method for processing substrates made of a fluororesin, which is difficult to process.

[0086] According to this method, a bonded body can be produced at a low cost in a short time at a temperature of about 50°C or less without applying high heat that melts the resin constituting the substrate, and since the obtained bonded body basically does not contain residual carbon dioxide, it is possible to easily obtain a clean bonded body with excellent safety, controllability and productivity, and to easily obtain a bonded body having a desired shape in which substrates are bonded together with excellent mechanical strength and sufficient adhesive strength. In particular, a bonded body can be obtained while maintaining the physical properties, shape, function, etc. of the substrates. Furthermore, according to the present method, when producing an adhesive body containing a functional material to be used according to the desired application, even if the functional material has poor heat resistance, it is possible to obtain an adhesive body that makes use of the functions, properties, etc. of the functional material. According to the method (I), an adherend can be formed without pressing the substrates together, and therefore the adherend can be obtained at low energy cost and through a simplified process. Furthermore, according to the present method (I), by placing a plurality of the structures in a pressure vessel, a plurality of bonded bodies can be formed in a single treatment (step 2), so that a plurality of bonded bodies can be obtained at low energy cost and through a simplified process.

[0087] It is not entirely clear why method (I) can provide an adhesive having excellent mechanical strength and a desired shape in which substrates are bonded together with sufficient adhesive strength. However, it is believed that the carbon dioxide introduced into the pressure vessel plasticizes the fluororubber in the adhesive, and this plasticization allows the substrates to be bonded and joined while interlocking with each other and fixing the shape. In addition, the reason why the present method (II) can provide an adhesive having excellent mechanical strength and a desired shape in which substrates are bonded together with sufficient adhesive strength is not entirely clear. However, it is believed that the application of pressure in the presence of liquid or gaseous carbon dioxide plasticizes the fluororubber in the adhesive, and the application of pressure in the plasticized state causes the fluororubber to become plasticized by the carbon dioxide. carbon It is believed that this is because the material becomes subcritical and plasticizes further, allowing the base materials to interlock and fix their shape, allowing them to be bonded and joined.

[0088] [glue] The adhesive used in this method is not particularly limited as long as it is an adhesive obtained from a fluororubber composition having a Mooney viscosity in the above range, and it is preferably a composition similar to the fluororubber composition described in the adhesive layer section. Specific examples of the adhesive include the fluororubber composition in a liquid or paste form (the fluororubber composition itself is an adhesive), a dried product of the fluororubber composition in a liquid or paste form (the dried product itself is an adhesive), and a fiber, nonwoven fabric or film obtained from the fluororubber composition (the fiber, nonwoven fabric or film itself is an adhesive). The adhesive used in this method may be one type or two or more types.

[0089] The liquid or paste-like fluororubber composition may contain a solvent capable of dispersing or dissolving the fluororubber, and in this case, it preferably contains a solvent capable of dissolving the fluororubber. In the present invention, there is no particular distinction between the liquid form and the paste form. The concentration of the fluororubber in the fluororubber composition containing the solvent is preferably 0.01% by mass or more, more preferably 0.5% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less.

[0090] According to this method, an adherend can be obtained while maintaining the shape of the adhesive and the substrate used, so that the effects of this method can be more effectively exhibited. Therefore, it is preferable to use a fiber or nonwoven fabric obtained from the fluororubber composition as the adhesive, and a substrate selected from a nonwoven fabric, a woven fabric, and a porous membrane as the substrate. By using such an adhesive and substrate, a totally porous adherend can be obtained, in which the entire adherend is porous.

[0091] The average fiber diameter of the fibers constituting the adhesive or nonwoven fabric is preferably 0.1 μm or more, more preferably 0.5 μm or more, and is preferably 5 μm or less, more preferably 3 μm or less.

[0092] The fiber length of the fibers constituting the adhesive or nonwoven fabric is not particularly limited, but is preferably 0.1 mm or more, more preferably 0.5 mm or more, and even more preferably 1 mm or more, and is preferably 1000 mm or less, more preferably 100 mm or less, and even more preferably 50 mm or less.

[0093] The porosity of the nonwoven fabric as the adhesive is not particularly limited, but is, for example, 0.1 vol. % or more, preferably 30 vol. % or more, and is, for example, 95 vol. % or less, preferably 90 vol. % or less.

[0094] The basis weight of the nonwoven fabric as the adhesive is preferably 100 g / m 2 or less, more preferably 1 to 80 g / m 2 It is.

[0095] The thickness of the nonwoven fabric or film used as the adhesive may be appropriately selected, but is usually 1 μm or more, preferably 3 μm or more, and usually 1 mm or less, preferably 200 μm or less. The nonwoven fabric used as the adhesive may be either a single layer or two or more layers made of different materials or different fiber diameters.

[0096] The fiber or nonwoven fabric serving as the adhesive is preferably produced by a method including a step A of spinning the fluororubber composition.

[0097] ·Process A Examples of the process A include electrospinning, melt spinning, melt electrospinning, and spunbonding (meltblowing). Of these, electrospinning and melt spinning are preferred, and electrospinning is particularly preferred because it can easily spin fibers of a desired shape, can obtain fibers with a small fiber diameter, and tends to result in nonwoven fabrics and the like obtained using the fibers that have a high porosity and a high specific surface area. For example, when step A is performed by electrospinning, the obtained fibers may be formed on a collector, in which case a nonwoven fabric is formed on the collector. Therefore, one embodiment of step A is also a method for producing a nonwoven fabric.

[0098] Specifically, to form a nonwoven fabric, for example, a step of forming fibers by an electrospinning method or the like and a step of accumulating the formed fibers into a sheet to form a nonwoven fabric may be carried out simultaneously, or after the step of forming fibers, a step of accumulating the formed fibers into a sheet to form a nonwoven fabric by a wet papermaking method, a water punching method, a chemical bonding method, a thermal bonding method, a spun bonding method, a needle punching method, a stitch bonding method or the like may be carried out.

[0099] When fibers or nonwoven fabrics are formed by electrospinning, a fluororubber composition, optionally containing a solvent, is preferably used.

[0100] In the fluororubber composition, for example, when the solubility of the fluororubber in a solvent is low, it is preferable to contain one or more fiber forming agents from the viewpoint of maintaining the fluororubber in a fibrous form during spinning. The fiber-forming agent is preferably an organic polymer having high solubility in a solvent, and examples thereof include polyethylene oxide, polyethylene glycol, dextran, alginic acid, chitosan, starch, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, cellulose, and polyvinyl alcohol. The amount of the fiber-forming agent used, depending on the viscosity of the solvent and the solubility in the solvent, is, for example, 0.1 mass % or more, preferably 1 mass % or more, and for example, 15 mass % or less, preferably 10 mass % or less, relative to 100 mass % of the fluororubber composition.

[0101] The conditions for electrospinning include, for example, the following conditions. The applied voltage (the voltage applied between the spinning nozzle and the fiber collecting collector) is preferably 1 kV or more, more preferably 5 kV or more, even more preferably 10 kV or more, and preferably 100 kV or less, more preferably 50 kV or less, even more preferably 40 kV or less. The spinning distance (the distance between the spinning nozzle and the fiber collecting collector) is preferably 5 to 30 cm. The discharge speed of the fluororubber composition is preferably 0.01 to 3 ml / min. The tip diameter (outer diameter) of the spinning nozzle used in electrospinning is preferably 0.1 mm or more, more preferably 0.2 mm or more, and is preferably 2.0 mm or less, more preferably 1.6 mm or less. The spinning atmosphere does not need to be particularly controlled, but it is preferable that the relative humidity is, for example, 10 to 50%, and the temperature is, for example, 10 to 35°C.

[0102] As the fiber collecting collector, a rotary collector or a flat collector can be used. When a rotary collector is used, the fibers ejected from the spinning nozzle are wound around the drum by rotating the drum, and a nonwoven fabric in which the fibers are oriented in a certain direction can be obtained. The rotation speed of the rotary collector is, for example, 50 to 5,000 revolutions per minute. When a flat fiber collecting collector is used, a nonwoven fabric made of non-oriented fibers can be obtained.

[0103] The melt spinning can be carried out, for example, by melting the fluororubber composition with heat, extruding it from a spinneret (nozzle) to form fibers, and then cooling it. The specific method of melt spinning is not particularly limited, and it can be carried out by a known method depending on the raw material used.

[0104] ·Process B When producing the fiber or nonwoven fabric as the adhesive, only the step A may be carried out. However, it is preferable to carry out the step B of crosslinking the fiber obtained in the step A, because the fiber shape (porous shape, nonwoven fabric shape) obtained in the step A can be maintained for a long period of time and fibers with improved tensile properties such as tensile strength and tensile modulus can be easily obtained. By carrying out step B in this manner, it is possible to obtain a fiber or nonwoven fabric containing at least one selected from a crosslinked product of an FKM and a crosslinked product of an FFKM.

[0105] Specific examples of step B include a step of irradiating the fiber or nonwoven fabric obtained in step A with radiation (radiation crosslinking) and a step of applying heat to the fiber or nonwoven fabric obtained in step A (thermal crosslinking). Of these, radiation crosslinking is preferred because it allows crosslinking treatment in a short time and makes it easy to maintain the fiber shape (porous shape, nonwoven fabric shape) obtained in step A. The fibers obtained in step A may be the fibers immediately after being extruded from the nozzle or the like, or the fibers (nonwoven fabric) after being accumulated on a collector or the like.

[0106] Examples of the radiation include X-rays, gamma rays, electron beams, proton beams, neutron beams, heavy particle beams, alpha rays, and beta rays, and among these, electron beams are preferable. The radiation to be irradiated may be of one type alone or of two or more types.

[0107] The radiation crosslinking may be carried out by a conventionally known method. In the case of irradiating with an electron beam, the conditions are, for example, as follows. It is desirable to irradiate with electron beams so that the absorbed dose is preferably 5 kGy or more, more preferably 10 kGy or more, even more preferably 20 kGy or more, and preferably 500 kGy or less, more preferably 300 kGy or less, even more preferably 150 kGy or less. Furthermore, the absorbed dose is preferably 30 to 100 kGy, for example, when a fiber or nonwoven fabric-like adhesive is used as described above, because it is easy to obtain an adhesive body having an adhesive layer in a shape that maintains the shape of the fiber or nonwoven fabric, and is preferably 30 to 70 kGy, because it is easy to obtain an adhesive body having an adhesive layer in a shape that maintains the shape of the fiber or nonwoven fabric and has excellent adhesive strength. The irradiation with radiation is preferably carried out in an atmosphere of an inert gas such as nitrogen or argon, since the crosslinking reaction is less likely to be inhibited and fibers or nonwoven fabrics having excellent mechanical properties can be easily obtained.

[0108] The heating conditions for the thermal crosslinking may be set according to the composition of the fluororubber composition used, and examples of the heating temperature include 150 to 200° C. and the heating time is 1 to 24 hours.

[0109] <Process I> The step I is not particularly limited as long as it is a step of preparing a structure in which an adhesive is disposed between substrates, and when forming this structure, one or more functional materials required for the intended use may be used according to the intended use. Examples of the functional materials include the same functional materials as those described in the adhesive body section.

[0110] The method for disposing the adhesive between the substrates is not particularly limited, but may be, for example, A method in which the fluororubber composition is formed in advance into an adhesive such as a fiber (including a line-shaped adhesive), a woven or nonwoven fabric (including a lattice-shaped adhesive), or a film (including a sphere-, particle- or dot-shaped adhesive), and the adhesive is then disposed between substrates; A method in which a substrate is immersed in a liquid or paste adhesive, or a liquid or paste adhesive is applied onto a substrate in a desired shape (e.g., film, line, dot, or grid), and the substrates are arranged so that the adhesive is between them (the adhesive may be dried as necessary before or after the substrates are arranged so that the adhesive is between them); Examples include:

[0111] Furthermore, when placing the adhesive between substrates, two or more substrates may be laminated with the adhesive interposed therebetween, or both ends of one substrate may be brought into contact (for example, a sheet-like substrate may be rolled so that both ends are brought into contact) and the adhesive may be placed between both ends of the brought-in substrate; or, as shown in FIG. 1, a laminate in which adhesive 2 is placed on a long substrate 1 may be spirally wound around a rod or cylindrical member 4 as shown in FIG. 2 and placed between substrates 1 (note that the portion 3 in FIG. 2 is a substrate / adhesive (adhesive layer) / substrate laminate portion in which adhesive 2 is placed between the substrate surface on the adhesive 2 side of substrate 1 in the laminate in FIG. 1 and the substrate surface on the opposite side to the adhesive 2 side of the laminate). When disposing the adhesive between the base materials, the base materials and the adhesive may be disposed while being wound around an auxiliary member such as a rod, if necessary.

[0112] The structure may be prepared by first forming a preliminary body by bonding one substrate and the adhesive in the presence of liquid or gaseous carbon dioxide, and then arranging the obtained preliminary body and a desired substrate to be bonded to the preliminary body, using the adhesive as necessary, so that the adhesive is located between the substrates.

[0113] Particularly when used in the method (I) above, in order to maintain the state of the structure, it is preferable to temporarily fix the structure using a temporary fixing means so that the substrate and the adhesive are in contact with each other, or to press the structure (to give it a shape) by hand or a device, etc. so that the substrate and the adhesive are in contact with each other. Examples of the temporary fixing means include clips, springs, tapes, staplers, screws, nails, needles, rubber bands, cable ties, weights, and magnets.

[0114] <Process 1> Step 1 is not particularly limited as long as it is a step of placing the structure obtained in step I into a pressure vessel. When placing a structure having an adhesive disposed between substrates into a pressure vessel, one structure may be placed in the pressure vessel, or multiple structures may be placed in the pressure vessel.

[0115] The pressure vessel is not particularly limited as long as it can withstand the pressure of carbon dioxide introduced in step 2. The size of the pressure vessel may be determined according to the size of the bonded body to be formed. The pressure vessel may be, for example, a vessel equipped with a carbon dioxide inlet, a valve for adjusting the amount of carbon dioxide introduced, a carbon dioxide outlet, and a valve for controlling the outlet.

[0116] <Process 2> The step 2 is not particularly limited as long as it is a step of introducing carbon dioxide into the pressure vessel having the structure obtained in the step 1, and it is preferable to introduce carbon dioxide in the form of liquid or gas. By this step 2, a bonded body is formed. The carbon dioxide to be introduced may be carbon dioxide in a subcritical or supercritical state. However, it is preferable not to use carbon dioxide in a subcritical or supercritical state, since carbon dioxide can be introduced without using a device having a heating mechanism or the like.

[0117] From the viewpoint of easily obtaining an adherend in which substrates are adhered to each other with sufficient adhesive strength without impairing the physical properties, shape, function, etc., of the substrates before adhesion, it is desirable to introduce carbon dioxide into the pressure vessel so that the pressure of carbon dioxide in the pressure vessel is preferably 3 MPa or more, more preferably 4 MPa or more, and even more preferably 5 MPa or more.

[0118] In step 2, it is preferable not to perform pressing with a pressing means. The surface pressure during bonding in step 2 (pressure in the lamination direction of the substrates) may be appropriately selected depending on the type of substrate used, the amount of adhesive, the desired shape of the bonded body, etc., but is preferably 10 gf / cm 2 More preferably, 100 gf / cm 2 or more, preferably 1000 gf / cm 2 Less than or equal to 500gf / cm 2 The following is the result. When the surface pressure is within the above range, it is possible to easily form an adhesive body in which the substrates are sufficiently bonded to each other without substantially damaging the shape of the substrates before bonding (e.g., the voids and fiber shape of a nonwoven fabric, etc.).

[0119] In step 2, it is believed that the fluororubber can be melted due to the melting point depression caused by the impregnation of the fluororubber in the adhesive with carbon dioxide, and an adhesive body can be formed without heating. Accordingly, in step 2, it is desirable to carry out the process at a temperature below the melting point of the fluororubber, preferably at a temperature of about 50°C or less, and more preferably without applying heat from the outside, in order to avoid impairing the function of the substrate, provide a high degree of freedom in selecting the substrate, and furthermore, in the case of forming an adhesive body containing a functional material, even if the functional material has poor heat resistance, it is possible to form an adhesive body that makes use of the functions and properties of the functional material. The temperature in step 2 is usually 0° C. or higher, preferably 20° C. or higher, and usually 40° C. or lower, preferably 30° C. or lower.

[0120] The time for step 2 (adhesion time) may be appropriately selected depending on the type and amount of the base material and adhesive used, etc., but is preferably 0.2 seconds or more, more preferably 1 second or more, and is preferably 15 minutes or less, more preferably 5 minutes or less.

[0121] <Process 3> When a temporary fixing means is used in the step I, the temporary fixing means is usually removed after the step 2 is carried out.

[0122] In one embodiment of the present invention, unlike an adhesive obtained by heat fusion, after carrying out step 3, a secondary process can be carried out in which the adhesive obtained is further bonded to another substrate.

[0123] <Step 4> The step 4 is not particularly limited as long as it is a step of pressing (bonding by pressing) the substrates as the step II, that is, a step of pressing the substrates in the structure obtained in the step I together in the presence of liquid or gaseous carbon dioxide.

[0124] The liquid or gaseous carbon dioxide is preferably carbon dioxide in a liquid state, a gas-liquid mixture state, or a state close to liquid state, from the viewpoints that it is believed that the fluororubber can be rapidly plasticized, and an adhesive having superior adhesive strength can be easily obtained. In step 4, carbon dioxide in a subcritical or supercritical state may be used. However, it is preferable not to use carbon dioxide in a subcritical or supercritical state, since this allows a reduction in the pressing force and allows compression bonding without using a device having a heating mechanism or the like.

[0125] As described above, it is believed that when pressure bonding is performed in the presence of liquid or gaseous carbon dioxide, the fluororubber in the adhesive is impregnated with carbon dioxide, plasticizing the fluororubber, and an adhesive body can be produced without heating. Therefore, in step 4, it is desirable to perform compression bonding at a temperature below the melting point of the fluororubber, preferably at a temperature of about 50°C or less, and more preferably without applying external heat, because the function of the substrate is not impaired, there is a high degree of freedom in selecting the substrate, and further, when an adhesive body containing a functional material is to be formed, even if the functional material has poor heat resistance, it is possible to form an adhesive body that makes use of the functions and properties of the functional material. In this case, the temperature during compression bonding in step 4 is usually 0° C. or higher, preferably 20° C. or higher, and usually 40° C. or lower, preferably 30° C. or lower.

[0126] Specifically, the step 4 is preferably carried out by introducing liquid or gaseous carbon dioxide into the system. When liquid or gaseous carbon dioxide is introduced into the system, the order in which the structure and carbon dioxide are introduced into the system is not particularly limited. For example, the structure may be introduced into a system filled with carbon dioxide, but it is preferable to introduce carbon dioxide into the system into which the structure has been introduced. When introducing liquid carbon dioxide, the compression step for liquefaction can be omitted compared to when introducing gaseous carbon dioxide, and therefore the bonded body can be produced in a short time. On the other hand, when gaseous carbon dioxide is introduced, the process is easier than when liquid carbon dioxide is introduced, and a pressure pump may be unnecessary, allowing the device to be simplified. When gaseous carbon dioxide is introduced, the introduced carbon dioxide may be pressurized to liquefy the carbon dioxide. In this case, it is not necessary to liquefy all of the introduced carbon dioxide, and it is sufficient to liquefy at least a portion of it.

[0127] The amount of carbon dioxide introduced is not particularly limited, but when gaseous carbon dioxide is introduced and compression bonding is performed at a temperature of 31°C (the critical temperature of carbon dioxide) or higher, for example, carbon dioxide is introduced so that the density of carbon dioxide during compression bonding is 0.4 g / mL or higher (about half the density of liquid carbon dioxide). Furthermore, in order to easily form an adhesive body in which substrates are bonded together with sufficient adhesive strength, when introducing gaseous carbon dioxide, it is desirable to introduce the carbon dioxide so that the pressure of the carbon dioxide introduced into the system is preferably 3 MPa or more, more preferably 4 MPa or more, and even more preferably 5 MPa or more.

[0128] The surface pressure during pressure bonding in step 4 may be appropriately selected depending on the type and amount of the base material used, the desired shape of the bonded body, etc., but is preferably 4 MPa or more, more preferably 5 MPa or more, and there is no particular upper limit, but it is, for example, 50 MPa or less. The surface pressure is the sum of the pressure of the carbon dioxide introduced into the system and the pressing pressure (when no pressing is performed, the pressure of the carbon dioxide introduced into the system).

[0129] The bonding time in step 4 may be appropriately selected depending on the type and amount of the base material and adhesive used, the surface pressure and temperature during bonding, etc., but is preferably 0.2 seconds or more, more preferably 1 second or more, and is preferably 15 minutes or less, more preferably 5 minutes or less.

[0130] Step 4 may be carried out in a sealed container capable of reducing the volume, or may be carried out using an open pressing device. The sealed container may, for example, have an inlet for introducing liquid or gaseous carbon dioxide into the sealed space and an outlet for carbon dioxide, and may have a member such as a piston that can reduce the volume of the sealed container to press the substrate.

[0131] When an open pressing device is used, the object to be treated can be treated in a spot manner without using a large treatment vessel that covers the entire substrate to be treated. For example, the substrate can be sent out and pressed repeatedly at a different position, or a roller can be used instead of a piston to press the substrate, thereby continuously producing an adhesive body.

[0132] Furthermore, according to one embodiment of the present invention, unlike an adhesive obtained by thermal fusion, after carrying out step 4, a secondary process can be carried out in which the adhesive obtained is further pressure-bonded to another substrate. EXAMPLES

[0133] Next, one embodiment of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these.

[0134] [Preparation Example 1] A fluororubber composition was prepared by dissolving 70 mass% of FKM1 (Dai-el G901H, Daikin Industries, Ltd., Mooney viscosity at 121°C measured in accordance with ASTM D 1646 (ML1+10): 135) and 30 mass% of FKM2 (Dai-el G902, Daikin Industries, Ltd., Mooney viscosity at 121°C measured in accordance with ASTM D 1646 (ML1+10): 21) in methyl ethyl ketone (special grade, Fujifilm Wako Pure Chemical Industries, Ltd.) so that the total concentration of FKM was 20 mass%. The resulting fluororubber composition had a Mooney viscosity (ML1+10) of 96 at 121° C. as measured in accordance with ASTM D 1646.

[0135] Using the prepared fluororubber composition, fluororubber fibers were directly spun (to form an uncrosslinked fluororubber nonwoven fabric) onto a collector with aluminum foil attached under the following conditions using an electrospinning device (manufactured by MEC Corporation).

[0136] (Spinning conditions) Voltage: 25kV Discharge amount: 2.0ml / min Discharge time: 1 hour Drum rotation speed: 300 rpm

[0137] The obtained non-crosslinked fluororubber nonwoven fabric was observed with an SEM (S-3400N, manufactured by Hitachi High-Technologies Corporation; the same device was used for the SEM below), and it was confirmed that the fibers constituting the nonwoven fabric had a fibrous shape. Not yet The crosslinked fluororubber nonwoven fabric had a thickness of 20 μm, and the average fiber diameter of the fibers constituting the uncrosslinked fluororubber nonwoven fabric was approximately 1 μm. The obtained uncrosslinked fluororubber nonwoven fabric was peeled off from the aluminum foil to prepare an adhesive layer A.

[0138] [Preparation Example 2] In the same manner as in Production Example 1, after forming an uncrosslinked fluororubber nonwoven fabric, the uncrosslinked fluororubber nonwoven fabric was irradiated with an electron beam (EB) using an EB apparatus (manufactured by Iwasaki Electric Co., Ltd., CB250 / 30 / 20 mA), and then the aluminum foil was peeled off to produce a crosslinked fluororubber nonwoven fabric. During this irradiation, at room temperature (21 °C), N 2 under the condition that the absorbed dose was 100 kGy, the electron beam was irradiated. The conveyance speed was 5 m / min. The obtained crosslinked fluororubber nonwoven fabric was observed by SEM image, and it was confirmed that the fibers constituting the nonwoven fabric had a fiber shape. The thickness of the obtained crosslinked fluororubber nonwoven fabric was 20 μm, and the average fiber diameter of the fibers constituting the crosslinked fluororubber nonwoven fabric was about 1 μm. The obtained crosslinked fluororubber nonwoven fabric was cut into a 5 mm × 20 mm square to produce Adhesive Layer B.

[0139] [Production Example 3] In Production Example 1, a fluororubber composition was prepared in the same manner as in Production Example 1, except that the amount of FKM1 used was changed to 80% by mass and the amount of FKM2 used was changed to 20% by mass. The Mooney viscosity (ML1+10) at 121 °C measured in accordance with ASTM D 1646 of the obtained fluororubber composition was 109. A crosslinked fluororubber nonwoven fabric was produced in the same manner as in Production Example 2, except that the obtained fluororubber composition was used.

[0140] [Production Example 4] In Production Example 1, a fluororubber composition was prepared in the same manner as in Production Example 1, except that the amount of FKM1 used was changed to 90% by mass and the amount of FKM2 used was changed to 10% by mass. The Mooney viscosity (ML1+10) at 121 °C measured in accordance with ASTM D 1646 of the obtained fluororubber composition was 120. A crosslinked fluororubber nonwoven fabric was produced in the same manner as in Production Example 2, except that the obtained fluororubber composition was used. The obtained crosslinked fluororubber nonwoven fabric was cut into a 5 mm × 20 mm square to produce Adhesive Layer D.

[0141] [Preparation Example 5] A fluororubber composition was prepared in the same manner as in Preparation Example 1, except that the amount of FKM1 used was changed to 50% by mass, and the amount of FKM2 used was changed to 50% by mass. The resulting fluororubber composition had a Mooney viscosity (ML1+10) of 69 at 121° C. as measured in accordance with ASTM D 1646. A crosslinked fluororubber nonwoven fabric was produced in the same manner as in Production Example 2, except that the obtained fluororubber composition was used. The resulting crosslinked fluororubber nonwoven fabric was cut into a 5 mm×20 mm square to prepare an adhesive layer E.

[0142] [Preparation Example 6] A fluororubber nonwoven fabric was produced in the same manner as in Production Example 1, except that the amount of FKM1 used was changed to 60 mass % and the amount of FKM2 used was changed to 40 mass %. The resulting fluororubber composition had a Mooney viscosity (ML1+10) of 86 at 121° C. as measured in accordance with ASTM D 1646. The obtained fluororubber nonwoven fabric was cut into a 5 mm×20 mm square to prepare an adhesive layer F.

[0143] [Example 1] Nonwoven fabric made of PTFE nanofibers hydrophilically treated with PVA (ZEUS Industrial Products, Inc., basis weight: 24 g / m 2 ) and adhesive layer A (adhesive layer A cut to a 5 mm x 20 mm square) prepared in Preparation Example 1 was placed between them, and the overlapping parts of the three sheets of the laminate were temporarily secured in place with clips. The temporarily fixed laminate was placed in a pressure vessel equipped with a pressure gauge, a carbon dioxide inlet, and a carbon dioxide outlet. Carbon dioxide gas was then slowly introduced into the pressure vessel over a period of 1 minute (final pressure inside the pressure vessel: 5 MPa), after which the carbon dioxide was immediately discharged and the clips were removed to produce an adhesive body. The obtained bonded structure had two nonwoven fabrics made of hydrophilically treated PTFE nanofibers bonded together with sufficient strength.

[0144] [Example 2] In Example 1, instead of two sheets of nonwoven fabric made of PTFE nanofibers hydrophilically treated with PVA, one sheet of nonwoven fabric made of PTFE nanofibers hydrophilically treated with PVA and one sheet of nonwoven fabric made of PTFE nanofibers not hydrophilically treated (manufactured by ZEUS Industrial Products, Inc., basis weight: 40 g / m) were used. 2 An adhesive bonded structure was prepared in the same manner as in Example 1, except that one sheet of adhesive (30 mm square) was used. In the obtained bonded structure, the nonwoven fabric made of the hydrophilically treated PTFE nanofiber and the nonwoven fabric made of the non-hydrophilically treated PTFE nanofiber were bonded with sufficient strength.

[0145] [Example 3] In Example 1, instead of the two sheets of nonwoven fabric made of PTFE nanofibers that had been hydrophilically treated with PVA, a nonwoven fabric made of PTFE nanofibers that had not been hydrophilically treated (manufactured by ZEUS Industrial Products, Inc., basis weight: 40 g / m 2 An adherend was prepared in the same manner as in Example 1, except that two sheets of the adhesive (30 mm square) were used. The obtained bonded structure had two nonwoven fabrics made of PTFE nanofibers that had not been hydrophilically treated bonded together with sufficient strength.

[0146] [Example 4] Nonwoven fabric made of PTFE nanofibers hydrophilically treated with PVA (ZEUS Industrial Products, Inc., basis weight: 40 g / m 2 A laminate in which adhesive layer A produced in Production Example 1 (adhesive layer A cut into a 10 mm x 10 mm square) was placed between two sheets of PTFE nanofiber (10 x 40 mm square) was placed on a SUS plate. Next, a magnet was placed on the part of the nonwoven fabric made of PTFE nanofiber that was not in contact with the SUS plate where the three sheets overlapped, and the laminate was temporarily fixed by magnetic force. The temporarily fixed laminate together with the SUS plate was placed in a pressure vessel equipped with a pressure gauge, a carbon dioxide inlet and a carbon dioxide outlet. Then, gaseous carbon dioxide was slowly introduced into the pressure vessel over a period of one minute (final pressure inside the pressure vessel: 5 MPa), after which the carbon dioxide was immediately discharged and the SUS plate and magnet were removed to produce an adhesive body. The obtained bonded structure had two nonwoven fabrics made of hydrophilically treated PTFE nanofibers bonded together with sufficient strength.

[0147] [Example 5] Nonwoven fabric made of PTFE nanofibers hydrophilically treated with PVA (ZEUS Industrial Products, Inc., basis weight: 40 g / m 2 A laminate in which the adhesive layer A (adhesive layer A cut into 25 mm x 10 mm squares) produced in Production Example 1 was placed between two sheets of adhesive (25 mm square x 25 mm square) was placed on the bottom of a pressure vessel having a pressure gauge, a carbon dioxide inlet, and a carbon dioxide outlet, so that the lamination direction was parallel to gravity. Then, a weight with an outer diameter of Φ19.5 mm and a weight of 94.7 g was placed on the part where the three sheets of the laminate overlapped. Next, gaseous carbon dioxide was slowly introduced into the pressure vessel over a period of one minute (final pressure in the pressure vessel: 5 MPa), and then the carbon dioxide was immediately discharged and the weight was removed to produce an adhesive body. The obtained bonded structure had two nonwoven fabrics made of hydrophilically treated PTFE nanofibers bonded together with sufficient strength.

[0148] [Example 6] Nonwoven fabric made of PTFE nanofibers hydrophilically treated with PVA (ZEUS Industrial Products, Inc., basis weight: 40 g / m 2Adhesive layer A (adhesive layer A cut into a 10 mm x 10 mm square) prepared in Preparation Example 1 was placed on one end of a nonwoven fabric (10 mm x 50 mm square, 10 mm x 50 mm square). Next, the 10 mm square portion of the end opposite to the side where adhesive layer A of the nonwoven fabric made of PTFE nanofiber was placed was rolled up so as to overlap with adhesive layer A, and the overlapping portion of the three sheets was temporarily fixed in a state where it was tightened with a jig (a fixing jig incorporating a precision compression spring (manufactured by Samini Co., Ltd.), free length: 10 mm, spring constant: 0.209 N / mm) until the length of the spring became 5 mm, thereby forming a ring-shaped laminate. A bonded body was produced in the same manner as in Example 1, except that the formed ring-shaped laminate was placed in a pressure vessel having a pressure gauge, a carbon dioxide inlet, and a carbon dioxide outlet. The obtained bonded structure was a ring-shaped bonded structure in which both ends of a single nonwoven fabric made of hydrophilically treated PTFE nanofiber were bonded with sufficient strength.

[0149] [Example 7] An adherend was produced in the same manner as in Example 1, except that adhesive layer B produced in Preparation Example 2 was used instead of adhesive layer A in Example 1. The obtained bonded structure had two nonwoven fabrics made of hydrophilically treated PTFE nanofibers bonded together with sufficient strength.

[0150] [Example 8] An adherend was produced in the same manner as in Example 1, except that the adhesive layer F produced in Preparation Example 6 was used instead of the adhesive layer A in Example 1. The obtained bonded structure had two nonwoven fabrics made of hydrophilically treated PTFE nanofibers bonded together with sufficient strength.

[0151] [Example 9] Nonwoven fabric made of PTFE nanofiber (ZEUS Industrial Products, Inc., basis weight: 24 g / m 21) and the adhesive layer A (adhesive layer A cut to 300 mm x 5 mm, adhesive 2 in FIG. 1) prepared in Preparation Example 1 was placed on a substrate 1 (300 mm x 20 mm, substrate 1 in FIG. 1) and the laminate was spirally wound around a φ6 mm SUS tube (cylindrical member) as shown in FIG. 2 so that the length of the laminated portion 3 in FIG. 2 was 5 mm. The SUS pipe having the spirally wound laminate was placed in a pressure vessel equipped with a pressure gauge, a carbon dioxide inlet and a carbon dioxide outlet. Gaseous carbon dioxide was then slowly introduced into the pressure vessel over a period of one minute (final pressure inside the pressure vessel: 5 MPa), after which the carbon dioxide was immediately discharged and the SUS pipe was removed to produce an adhesive body. The obtained bonded body was tubular (cylindrical), and the nonwoven fabric made of PTFE nanofiber was bonded with sufficient strength at the bonded portion (substrate / adhesive layer / substrate laminate portion 3 in FIG. 2). The average peel strength in Table 1 below is the measured peel strength of the obtained bonded body at substrate / adhesive (adhesive layer) / substrate laminate portion 3 in FIG. 2.

[0152] [Comparative Example 1] An attempt was made to prepare an adhesive structure in the same manner as in Example 7, except that carbon dioxide was not introduced, but when the clips were removed, the two sheets of nonwoven fabric made of hydrophilic-treated PTFE nanofiber peeled off and did not adhere to each other. In other words, the desired adhesive structure could not be prepared.

[0153] [Comparative Example 2] An adherend was produced in the same manner as in Example 7, except that adhesive layer D produced in Preparation Example 4 was used instead of adhesive layer B in Example 7. In the obtained bonded structure, the two nonwoven fabrics made of hydrophilically treated PTFE nanofibers were not bonded with sufficient strength, meaning that the desired bonded structure could not be produced.

[0154] [Comparative Example 3] An adherend was prepared in the same manner as in Example 7, except that the adhesive layer E prepared in Preparation Example 5 was used instead of the adhesive layer B in Example 7. In the obtained bonded structure, the two nonwoven fabrics made of hydrophilically treated PTFE nanofibers were not bonded with sufficient strength, meaning that the desired bonded structure could not be produced.

[0155] <Peel strength test> The mechanical properties of the obtained bonded bodies were measured using a universal tensile testing machine (EZ-test, manufactured by Shimadzu Corporation) by tearing the bonded bodies in the bonding direction at a speed of 1 mm / s (applying a tensile load perpendicular to the bonded surface) and measuring the average peel strength (N / 10 mm) of the bonded bodies at a displacement of 5 to 10 mm (5 to 10 seconds after tearing). When the average peel strength was 1 N / 10 mm or more, it was rated as AA, when the average peel strength was 0.3 N / 10 mm or more but less than 1 N / 10 mm, it was rated as BB, and when the average peel strength was less than 0.3 N / 10 mm, it was rated as CC. The results are shown in Table 1. When there was no adhesion, it is indicated as "no adhesion" in Table 1.

[0156] [Table 1]

[0157] [Example 10] In the same manner as in Preparation Example 1, an uncrosslinked fluororubber nonwoven fabric was formed, and then the uncrosslinked fluororubber nonwoven fabric was irradiated with an electron beam (EB) using an EB device (manufactured by Iwasaki Electric Co., Ltd., CB250 / 30 / 20mA), and the resulting crosslinked fluororubber nonwoven fabric was peeled off from the aluminum foil and cut into a 5 mm x 20 mm square to prepare an adhesive layer. 2 The specimens were irradiated with electron beams under conditions of absorbed doses of 30, 40, 50, 60, 70, 80, or 100 kGy.

[0158] Nonwoven fabric made of PTFE nanofiber (ZEUS Industrial Products, Inc., basis weight: 24 g / m 2) The prepared adhesive layer was placed between the two sheets of the laminate, and the overlapping portion of the three sheets of the laminate was lightly pressed together with a hand. The pressed laminate was placed in a pressure vessel equipped with a pressure gauge, a carbon dioxide inlet and a carbon dioxide outlet, and then gaseous carbon dioxide was slowly introduced into the pressure vessel over a period of one minute (final pressure inside the pressure vessel: 6 MPa), after which the carbon dioxide was immediately discharged to produce an adhesive body. The average peel strength of the prepared bonded structure was measured in the same manner as described above. The results are shown in Table 2.

[0159] [Table 2]

[0160] [Example 11] Nonwoven fabric made of PTFE nanofibers with an average fiber diameter of 900 nm (ZEUS Industrial Products, Inc., basis weight: 24 g / m 2 ) The substrate was prepared by punching each of the two sheets into a circle with a diameter of 19 mm. In addition, the cross-linked fluororubber nonwoven fabric produced in Preparation Example 2 was punched out into a circle with a diameter of 19 mm to produce an adhesive.

[0161] The laminate in which the obtained substrate, the obtained adhesive, and the obtained substrate were laminated in this order was placed in a sealable container (diameter: φ20 mm, container described in JP 2018-099885 A) having a piston, a carbon dioxide inlet, and a carbon dioxide outlet, was placed therein, and carbon dioxide equivalent to the vapor pressure of carbon dioxide (cylinder pressure: 6 MPa) was introduced therein at room temperature (25 ° C), the piston was lowered to reduce the volume inside the container (while liquefying carbon dioxide), and a pressure of 500 N was applied for 10 seconds to pressure-bond the two substrates with the adhesive (crosslinked fluororubber nonwoven fabric). After that, the carbon dioxide was instantly discharged while maintaining the pressure, and then the pressure was released, and the obtained φ20 mm bonded body (pressure-bonded body) was taken out of the container. During the lamination, a polyimide film was sandwiched between the base material and the adhesive (so as to protrude outward), which would become the peeling portion (tongue) in the peel strength test. The average peel strength of the resulting bonded body (pressure-bonded body) was measured in the same manner as above. The results are shown in Table 3.

[0162] [Example 12] A bonded article (compression bonded article) was produced in the same manner as in Example 11, except that the crosslinked fluororubber nonwoven fabric produced in Production Example 3 was used instead of the crosslinked fluororubber nonwoven fabric produced in Production Example 2. The average peel strength of the resulting bonded article (compression bonded article) was measured in the same manner as described above. The results are shown in Table 3.

[0163] [Comparative Example 4] A bonded body (pressure-bonded body) was produced in the same manner as in Example 11, except that carbon dioxide was not introduced. In the obtained bonded body (compression bonded body), the substrate and the adhesive (crosslinked fluororubber nonwoven fabric) were not bonded, which means that the desired bonded body (compression bonded body) could not be produced.

[0164] [Comparative Example 5] A bonded body (compression-bonded body) was prepared in the same manner as in Example 11, except that the crosslinked fluororubber nonwoven fabric prepared in Preparation Example 4 was used instead of the crosslinked fluororubber nonwoven fabric prepared in Preparation Example 2. The obtained bonded body (compression bonded body) had insufficient adhesion between the substrate and the adhesive (crosslinked fluororubber nonwoven fabric) (average peel strength: less than 0.3 N / 10 mm), and the substrate and the adhesive peeled off. In other words, the desired bonded body (compression bonded body) could not be produced.

[0165] [Comparative Example 6] A bonded body (compression-bonded body) was prepared in the same manner as in Example 11, except that the crosslinked fluororubber nonwoven fabric prepared in Preparation Example 5 was used instead of the crosslinked fluororubber nonwoven fabric prepared in Preparation Example 2. The obtained bonded body (compression bonded body) had insufficient adhesion between the substrate and the adhesive (crosslinked fluororubber nonwoven fabric) (average peel strength: less than 0.3 N / 10 mm), and the substrate and the adhesive peeled off. In other words, the desired bonded body (compression bonded body) could not be produced.

[0166] [Table 3] [Explanation of symbols]

[0167] 1: Base material 2: Glue 3: Substrate / adhesive (adhesive layer) / substrate laminate 4: Rod or tubular member

Claims

1. A fluororubber composition for forming an adhesive layer for bonding substrates together, comprising: A fluororubber composition for bonding substrates together in the presence of carbon dioxide in a liquid state, a gas-liquid mixed state, or a state having a density of 0.4 g / mL or more, The fluororubber composition contains at least one fluororubber selected from a fluoroelastomer and a perfluoroelastomer, and has a Mooney viscosity ML1+10 at 121°C measured in accordance with ASTM D 1646 of 80 to 115. Fluororubber composition.

2. The fluororubber composition is A fluororubber (A1) having a Mooney viscosity ML1+10 of 40 to 150 at 121°C measured in accordance with ASTM D 1646; A fluororubber (A2) having a Mooney viscosity ML1+10 at 121°C measured in accordance with ASTM D 1646 of 10 or more and less than 40; The fluororubber composition according to claim 1, comprising:

3. 3. The fluororubber composition according to claim 1, wherein the fluororubber comprises a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene polymer.

4. A method for producing an adhesive body, comprising the steps of: Providing a structure having an adhesive disposed between substrates; placing the structure in a pressure vessel; introducing carbon dioxide into the pressure vessel; bonding the structure in the presence of liquid or gaseous carbon dioxide; Including, the adhesive is obtained from a fluororubber composition having a Mooney viscosity ML1+10 of 80 to 115 at 121°C measured in accordance with ASTM D 1646; The step of introducing carbon dioxide into the pressure vessel is a step of introducing liquid or gaseous carbon dioxide so that the pressure in the pressure vessel is 3 MPa or more. A method for producing an adhesive body.

5. The method for producing an adhesive body according to claim 4, wherein the fluororubber composition contains at least one kind of fluororubber selected from a fluoroelastomer and a perfluoroelastomer.

6. The fluororubber composition is A fluororubber (A1) having a Mooney viscosity ML1+10 of 40 to 150 at 121°C measured in accordance with ASTM D 1646; A fluororubber (A2) having a Mooney viscosity ML1+10 at 121°C measured in accordance with ASTM D 1646 of 10 or more and less than 40; A method for producing the adhesive body according to claim 4 or 5, comprising:

7. The method for producing an adhesive body according to any one of claims 4 to 6, wherein the fluororubber composition contains a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene polymer.

8. The method for producing an adhesive body according to any one of claims 4 to 7, wherein the adhesive is the fluororubber composition in a liquid or paste form, a dried product of the fluororubber composition in a liquid or paste form, or a fiber, nonwoven fabric or film obtained from the fluororubber composition.

9. The adhesive is A step of spinning the fluororubber composition; and Step B of crosslinking the fibers obtained in step A The fluororubber fiber or fluororubber nonwoven fabric is obtained by a method comprising the steps of: The method for producing the bonded body according to any one of claims 4 to 8.

10. The method for producing an adhesive article according to any one of claims 4 to 9, wherein at least one of the substrates is a nonwoven fabric, a woven fabric, a porous membrane or a fiber.

11. The substrate is selected from a nonwoven fabric, a woven fabric, and a porous membrane; The adhesive is a fiber or a nonwoven fabric obtained from the fluororubber composition. The method for producing the bonded body according to any one of claims 4 to 10.

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