Laminate, belt, and method for manufacturing laminate

Abstract

This laminate comprises: a fluororesin layer that contains at least one fluororesin selected from the group consisting of an ethylene-tetrafluoroethylene copolymer, a tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer, and a tetrafluoroethylene-hexafluoropropylene copolymer; an adhesive layer that is disposed on one main surface of the fluororesin layer and contains an aminosilane coupling agent; and a resin substrate that is provided on the surface of the adhesive layer opposite to the surface on which the fluororesin layer is disposed, the resin substrate containing at least one resin selected from the group consisting of polyvinyl chloride, olefin resin, acrylic resin, epoxy resin, nylon, polycarbonate, and thermoplastic polyurethane.

Description

Laminate, belt, and method for manufacturing laminate

[0001] FIELD The present disclosure relates to laminates, belts, and methods for making laminates.

[0002] Laminates including a fluororesin layer with excellent properties such as heat resistance, water repellency, and oil repellency are utilized in a wide range of fields. Examples of such laminates include industrial belts. Belts made of thermoplastic polyurethane are used as industrial belts because they can be bonded and deformed by heating. However, thermoplastic polyurethane has issues such as its tendency to adhere to other components and its low heat resistance, so a fluororesin with excellent non-adhesive properties and heat resistance is sometimes laminated onto the thermoplastic polyurethane layer. For example, Patent Document 1 describes that a laminate in which an ethylene-tetrafluoroethylene copolymer film and a base belt containing a thermoplastic polyurethane film are bonded via an adhesive is suitable for belt applications.

[0003] Japanese Patent Application Publication No. 10-151683

[0004] However, the laminate described in Patent Document 1 sometimes had insufficient adhesive strength and low peel strength. Furthermore, food processing belts are sometimes heated to about 80°C during use, and there was a problem that the peel strength decreased when exposed to heat at such a temperature. Similar problems occurred when using resin substrates other than thermoplastic polyurethane, such as polyvinyl chloride, olefin resin, acrylic resin, epoxy resin, nylon, or polycarbonate.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a laminate, a belt, and a method for manufacturing a laminate that has high peel strength and that prevents a decrease in peel strength even when heated to 80°C.

[0006] Specific means for achieving the above object are as follows: <1> A laminate comprising: a fluororesin layer containing at least one fluororesin selected from the group consisting of ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer; an adhesive layer disposed on one main surface of the fluororesin layer and containing an aminosilane coupling agent; and a resin substrate disposed on the surface of the adhesive layer opposite to the surface on which the fluororesin layer is disposed and containing at least one resin selected from the group consisting of polyvinyl chloride, olefin resin, acrylic resin, epoxy resin, nylon, polycarbonate, and thermoplastic polyurethane. <2> A laminate comprising: a fluororesin layer having an amino group content of 0.01 to 2.5 mmol / m ２<3> The laminate according to <1> or <2>, wherein the adhesive layer has an average thickness of 1 μm or less. <4> The laminate according to any one of <1> to <3>, wherein the ethylene-tetrafluoroethylene copolymer content in the fluororesin layer is 90% by mass or more. <5> The laminate according to any one of <1> to <4>, wherein the resin substrate contains a pigment. <6> The laminate according to any one of <1> to <5>, wherein the resin substrate contains at least one selected from the group consisting of an ethylene resin, a polyester-based thermoplastic polyurethane, and a polyether-based thermoplastic polyurethane. <7> The laminate according to any one of <1> to <6>, wherein the difference between the melting temperature of the fluororesin layer and the softening temperature of the resin substrate is 50 to 200°C. <8> The laminate according to any one of <1> to <7>, wherein at least one of the surface of the fluororesin layer facing the adhesive layer and the surface of the resin substrate facing the adhesive layer is surface-treated. <9> The laminate according to any one of <1> to <8>, wherein the peel strength between the fluororesin layer and the resin substrate at 23°C is 2.0 N or more. <10> The laminate according to any one of <1> to <9>, wherein the ratio of the peel strength between the fluororesin layer and the resin substrate at 80°C to the peel strength at 23°C is 0.6 or more. <11> A belt having the laminate according to any one of <1> to <10>. <12> A method for producing a laminate, comprising: a fluororesin layer containing at least one fluororesin selected from the group consisting of an ethylene-tetrafluoroethylene copolymer, a tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and a tetrafluoroethylene-hexafluoropropylene copolymer; an adhesive layer containing an aminosilane coupling agent; and a resin substrate containing at least one resin selected from the group consisting of polyvinyl chloride, an olefin resin, an acrylic resin, an epoxy resin, nylon, polycarbonate, and thermoplastic polyurethane, directly stacked in this order and heat-pressed to obtain the laminate according to any one of <1> to <11>. <13> The method for producing a laminate according to <12>, wherein the heat pressing is performed so that a total thickness of the fluororesin layer, the adhesive layer, and the resin substrate after the heat pressing is 85% or less of that before the heat pressing.<14> The method for producing a laminate according to <12> or <13>, wherein the heat press temperature is equal to or higher than the softening temperature of the resin substrate and equal to or lower than the softening temperature of the resin substrate + 100° C. <15> The method for producing a laminate according to any one of <12> to <14>, wherein the heat press temperature is 160 to 190° C.

[0007] According to one aspect of the present disclosure, it is possible to provide a laminate, a belt, and a method for manufacturing a laminate, which have high peel strength and are prevented from decreasing even when heated to 80°C.

[0008] 1 is a cross-sectional schematic diagram illustrating an example of a laminate according to the present disclosure.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure.

[0010] In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. Furthermore, in numerical ranges described in the present disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, particles corresponding to each component may include multiple types of particles. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0011] In this disclosure, the term "unit" of a polymer refers to a portion derived from a monomer that exists in the polymer and constitutes the polymer. The term "unit" also refers to a unit obtained by chemically converting the structure of a unit after polymer formation. In some cases, units derived from individual monomers are referred to by the name of the monomer followed by "unit."

[0012] In this disclosure, films and sheets are referred to as "films" regardless of their thickness. In this disclosure, "(meth)acrylic" means at least one of acrylic and methacrylic. When embodiments are described with reference to drawings in this disclosure, the configuration of the embodiment is not limited to the configuration shown in the drawings. In addition, the sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to these.

[0013] <Laminate> The laminate of the present disclosure comprises: a fluororesin layer containing at least one fluororesin selected from the group consisting of ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer; an adhesive layer disposed on one main surface of the fluororesin layer and containing an aminosilane coupling agent; and a resin substrate provided on the surface of the adhesive layer opposite to the surface on which the fluororesin layer is disposed and containing at least one resin selected from the group consisting of polyvinyl chloride, olefin resin, acrylic resin, epoxy resin, nylon, polycarbonate, and thermoplastic polyurethane.

[0014] [Fluororesin Layer] The fluororesin layer contains at least one fluororesin selected from the group consisting of ethylene-tetrafluoroethylene copolymer (hereinafter also referred to as "ETFE"), tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (hereinafter also referred to as "PFA"), and tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter also referred to as "FEP"). ETFE, PFA, and FEP may each be used alone or in combination of two or more. These fluororesins may further contain units derived from other monomers, as necessary, to the extent that their essential properties are not impaired. The melting point of the fluororesin is preferably 190 to 320°C, more preferably 220 to 310°C.

[0015] ETFE is a copolymer having tetrafluoroethylene units (hereinafter referred to as TFE units) and ethylene units. The molar ratio of TFE units to ethylene units in ETFE (TFE units / ethylene units) is preferably 20 / 80 to 80 / 20, more preferably 30 / 70 to 70 / 30, and even more preferably 40 / 60 to 60 / 40.

[0016] ETFE may have other monomer units in addition to TFE units and ethylene units. The proportion of the other monomer units is preferably 10 mol% or less, more preferably 6 mol% or less, and even more preferably 3 mol% or less, relative to the total (100 mol%) of all monomer units of ETFE.

[0017] The other monomer may be copolymerizable with tetrafluoroethylene and ethylene, for example, CF ２ = CFCl, CF ２ =CH ２ Fluoroethylenes (excluding TFE) such as hexafluoropropylene and octafluorobutene-1; perfluoroolefins having 3 to 5 carbon atoms such as X(CF ２ ) ｎ CY=CH ２ (wherein X and Y each independently represent a hydrogen atom or a fluorine atom, and n represents an integer of 2 to 8); ｆ (OCFXCF２ ) ｍ OCF = CF ２ (However, R ｆ represents a perfluoroalkyl group having 1 to 6 carbon atoms, X represents a fluorine atom or a trifluoromethyl group, and m represents an integer of 0 to 5; ３ OC(=O)CF ２ CF ２ CF ２ OCF = CF ２ , FSO ２ CF ２ CF ２ OCF (CF ３ )CF ２ OCF = CF ２ perfluorovinyl ethers having a group that can be easily converted into a carboxylic acid group or a sulfonic acid group, such as CF ２ = CFOCF ２ CF = CF ２ , C.F. ２ = CFO (CF ２ ) ２ CF = CF ２ perfluorovinyl ethers having two or more unsaturated bonds, such as perfluoro(2,2-dimethyl-1,3-dioxole), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole, perfluoro(2-methylene-4-methyl-1,3-dioxolane), and the like; fluorine-containing monomers having an alicyclic structure, such as perfluoro(2,2-dimethyl-1,3-dioxole), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole, and perfluoro(2-methylene-4-methyl-1,3-dioxolane); and olefins having three or more carbon atoms, such as olefins having three carbon atoms (propylene, etc.) and olefins having four carbon atoms (butylene, isobutylene, etc.).

[0018] X (CF ２ ) ｎ CY=CH ２ In the polyfluoroalkylethylenes represented by the formula (I), n is preferably 2 to 6, more preferably 2 to 4. Specific examples include CF ３ CF ２ CH=CH ２ , C.F. ３ CF ２ CF ２ CF ２ CH=CH ２ , C.F. ３ CF２ CF ２ CF ２ CF=CH ２ , C.F. ２ HCF ２ CF ２ CF=CH ２ , C.F. ２ HCF ２ CF ２ CF=CH ２ etc. ｆ (OCFXCF ２ ) ｍ OCF = CF ２ Specific examples of perfluorovinyl ethers such as perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), CF ２ = CFOCF ２ CF (CF ３ ) O(CF ２ ) ２ CF ３ , C.F. ２ = CFO (CF ２ ) ３ O (CF ２ ) ２ CF ３ , C.F. ２ = CFO (CF ２ CF (CF ３ ) O) ２ (CF ２ ) ２ CF ３ , C.F. ２ = CFOCF ２ CF (CF ３ ) O(CF ２ ) ２ CF ３ etc.

[0019] As the other monomers, the polyfluoroalkylethylenes, hexafluoropropylene, and perfluoro(propyl vinyl ether) are preferred, and CF ３ CF ２ CH=CH ２ , C.F. ３ (CF ２ ) ３ CH=CH ２, hexafluoropropylene, and perfluoro(propyl vinyl ether) are more preferred. These other monomers may be used alone or in combination of two or more.

[0020] The melting point of ETFE is preferably 190°C or higher, more preferably 200°C or higher, even more preferably 210°C or higher, and particularly preferably 220°C or higher. The upper limit of the melting point of ETFE is not particularly limited, but is, for example, 270°C. When the melting point of ETFE is within this range, the laminate tends to have excellent heat resistance, and even when heated to 80°C, the peel strength of the laminate of the present disclosure is unlikely to decrease. "Melting point" means the temperature corresponding to the maximum value of the melting peak measured by differential scanning calorimetry (DSC).

[0021] The melt flow rate (MFR) of ETFE is preferably 2 to 40 g / 10 min, more preferably 3 to 30 g / 10 min, and even more preferably 5 to 20 g / 10 min. When the MFR of ETFE is within this range, it tends to have excellent flexibility. The MFR of ETFE and the PFA and FEP described below is a value measured in accordance with ASTM D3159 at a load of 49 N and 297°C.

[0022] From the viewpoint of the bending resistance of the laminate of the present disclosure, the elastic modulus of ETFE is preferably 600 to 1200 MPa, more preferably 800 to 1000 MPa. The elastic modulus of ETFE is a value measured in accordance with ASTM D638.

[0023] PFA is a copolymer containing TFE units and units based on perfluoro(alkyl vinyl ether) (hereinafter referred to as PAVE units). The molar ratio of TFE units to PAVE units in PFA (TFE units / PAVE units) is preferably 90 / 10 to 99 / 1, more preferably 95 / 5 to 99 / 1.

[0024] The melting point of the PFA is preferably 280 to 320° C., more preferably 290 to 310° C. The MFR of the PFA is preferably 1 to 40 g / 10 min, more preferably 3 to 10 g / 10 min. When the MFR of the PFA is in this range, it tends to have excellent flexibility.

[0025] FEP is a copolymer containing TFE units and units based on hexafluoropropylene (hereinafter referred to as HFP units). The molar ratio of TFE units to HFP units in FEP (TFE units / HFP units) is preferably 75 / 25 to 95 / 5, more preferably 85 / 15 to 93 / 7.

[0026] In addition to TFE units and HFP units, FEP may have other monomer units such as PAVE units. The proportion of the other monomer units is preferably 10 mol% or less, more preferably 6 mol% or less, and even more preferably 3 mol% or less, relative to the total (100 mol%) of all monomer units of FEP.

[0027] The melting point of FEP is preferably 260 to 300° C., more preferably 270 to 290° C. The MFR of FEP is preferably 1 to 40 g / 10 min., more preferably 5 to 20 g / 10 min. When the MFR of FEP is in this range, it tends to have excellent flexibility.

[0028] Among the above fluororesins, the fluororesin layer preferably contains ETFE from the viewpoint of peel strength.

[0029] The fluororesin layer may contain other fluororesins in addition to ETFE, PFA, and FEP. Examples of the other fluororesins include vinyl fluoride polymers, vinylidene fluoride polymers, vinylidene fluoride-hexafluoropropylene copolymers, tetrafluoroethylene-propylene copolymers, and tetrafluoroethylene-vinylidene fluoride-propylene copolymers. One type of the other fluororesins may be used alone, or two or more types may be used in combination.

[0030] The content of ETFE relative to the total fluororesin contained in the fluororesin layer is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and particularly preferably 100% by mass. That is, it is particularly preferable that the fluororesin is ETFE.

[0031] The fluororesin layer may contain other resins besides fluororesin, such as (meth)acrylic resin, polycarbonate, ethylene resin, propylene resin, polyethylene terephthalate, polybutylene terephthalate, nylon, etc.

[0032] The content of the fluororesin in the fluororesin layer is preferably 50% by mass or more, more preferably 90% by mass or more, even more preferably 98% by mass or more, and particularly preferably 100% by mass. The content of ETFE in the fluororesin layer is preferably 50% by mass or more, more preferably 90% by mass or more, even more preferably 98% by mass or more, and particularly preferably 100% by mass.

[0033] The fluororesin layer may contain components other than the resin. Examples of the other components include copper compounds such as copper oxide and copper iodide, hydrophobizing agents, antioxidants, pigments, mica, and antibacterial agents. The content of these additives is preferably determined appropriately so that the additives can perform their functions without deteriorating the appearance of the film.

[0034] The inclusion of a copper compound improves the heat resistance of the fluororesin layer. The average particle size of the copper compound is preferably 1 to 50 μm. The copper compounds may be used alone or in combination of two or more.

[0035] Examples of the antioxidant include known antioxidants such as phosphorus-containing antioxidants, phenolic antioxidants, sulfur-containing antioxidants, etc. One type of antioxidant may be used alone, or two or more types may be used in combination.

[0036] Examples of the hydrophobizing agent include a silane coupling agent having an alkyl group, a silicone compound, etc. One type of hydrophobizing agent may be used alone, or two or more types may be used in combination.

[0037] The pigment may be a pigment for coloring the fluororesin layer. A commonly used pigment may be used. One type of pigment may be used alone, or two or more types may be used in combination.

[0038] Examples of pigments include black pigments typified by carbon black, blue pigments typified by cobalt oxide, red pigments typified by iron oxide, yellow pigments such as cerium oxide, and white pigments typified by titanium oxide, silicon oxide, zinc oxide, and cerium oxide. Of these, carbon black and titanium oxide are preferred, and carbon black is more preferred from the viewpoint of improving the ultraviolet shielding properties and antistatic performance of the laminate of the present disclosure and from the viewpoint of adjusting the hardness.

[0039] The pigment content in the fluororesin layer is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, and particularly preferably 2.5% by mass or more. From the viewpoint of excellent kneadability when kneading the pigment into the fluororesin, the pigment content in the fluororesin layer is preferably 15.0% by mass or less, more preferably 13.0% by mass or less, and even more preferably 11.0% by mass or less.

[0040] The average thickness of the fluororesin layer is preferably 10 μm or more, more preferably 12 μm or more, and even more preferably 20 μm or more, and the upper limit is preferably 300 μm or less, and even more preferably 250 μm or less.

[0041] The average thickness of the fluororesin layer can be determined by measuring five points on the cross section of the laminate using a microscope and calculating the average value.

[0042] The melting temperature of the fluororesin layer is preferably 190°C or higher, more preferably 200°C or higher, even more preferably 210°C or higher, and particularly preferably 220°C or higher. The upper limit of the melting temperature of the fluororesin layer is not particularly limited, but is, for example, 270°C. When the melting temperature of the fluororesin layer is within this range, the laminate tends to have excellent heat resistance, and even when heated to 80°C, the peel strength of the laminate of the present disclosure is unlikely to decrease. "Melting temperature" means the temperature corresponding to the maximum value of the melting peak measured by differential scanning calorimetry (DSC).

[0043] The fluororesin layer may have an uneven structure on at least one surface. When an uneven structure is provided on the surface of the fluororesin layer facing the adhesive layer, the adhesion area with the adhesive layer increases, and the laminate of the present disclosure is likely to have excellent peel strength. When an uneven structure is provided on the surface opposite the adhesive layer of the fluororesin layer, the laminate of the present disclosure is likely to have excellent slip properties. For example, when the laminate of the present disclosure is used as a food belt, the contact area between the laminate of the present disclosure and food is reduced, and the laminate of the present disclosure and food are likely to stick less. The laminate of the present disclosure does not need to have an uneven structure on its surface, and may be mirror-finished.

[0044] The arithmetic mean roughness Ra of the surface having a concave-convex structure is preferably 0.3 to 3.0 μm, more preferably 0.8 to 3.0 μm, and even more preferably 1.0 to 2.5 μm. The depth of the concave-convex structure may be set shallower, in which case Ra is preferably 0.3 to 2.0 μm, more preferably 0.8 to 1.8 μm, and even more preferably 1.0 to 1.6 μm. On the other hand, the depth of the concave-convex structure may be set deep, in which case Ra is preferably 0.6 to 3.0 μm, more preferably 1.7 to 3.0 μm, and even more preferably 1.8 to 2.5 μm.

[0045] The maximum height roughness Rz of the surface having the uneven structure is preferably 1 to 25 μm, more preferably 4 to 25 μm, and even more preferably 4 to 22 μm. When the depth of the unevenness is set to be shallow, Rz is preferably 1 to 8 μm, more preferably 4 to 7 μm, and even more preferably 4 to 6 μm. When the depth of the unevenness is set to be deep, Rz is preferably 13 to 25 μm, more preferably 15 to 25 μm, and even more preferably 18 to 22 μm.

[0046] The arithmetic mean roughness Ra and the maximum height roughness Rz refer to values ​​measured by the method described in JIS B0601:2013 (ISO4287:1997, Amd.1:2009).

[0047] [Adhesive Layer] The adhesive layer contains an aminosilane coupling agent. When a general adhesive is used as the adhesive layer, volatile gases are generated when heated to about 80°C, which is a concern when the laminate is used as a belt for food processing, for example. In contrast, aminosilane coupling agents do not generate volatile gases when heated to about 80°C. The aminosilane coupling agents may be used alone or in combination of two or more. The aminosilane coupling agent may have one or more amino groups, or may have two or more amino groups.

[0048] The aminosilane coupling agent includes a compound represented by the following general formula (1).

[0049]

[0050] In formula (1), R １ represents an alkyl group, and R ２ and R ３ each independently represents a hydrogen atom, an alkyl group, an aminoalkyl group, a phenyl group, or an aminocarbonyl group.

[0051] R １ The alkyl group represented by R preferably has 1 to 3 carbon atoms, and more preferably has 1 or 2 carbon atoms. ２ and R ３ The aminoalkyl group as R is preferably an aminomethyl group, an aminoethyl group, or an aminopropyl group. The aminoalkyl group may have a substituent. Examples of the substituent include a phenyl group. ２ and R ３ The alkyl group represented by R may have a substituent. Examples of the substituent include a phenyl group and a vinylphenyl group. ２ and R ３ The phenyl group as may have a substituent, such as a vinyl group.

[0052] The aminosilane coupling agent, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropylmethyldimethoxysilane, or N-phenyl-3-aminopropylmethyldiethoxysilane is preferred, and from the viewpoint of obtaining stable adhesive strength, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or 3-aminopropylmethyldimethoxysilane is more preferred.

[0053] The amount of amino groups contained in the adhesive layer is 0.01 to 2.5 mmol / m ２ is preferably 0.1 to 2.3 mmol / m ２ More preferably, 0.5 to 2.0 mmol / m ２ More preferably, the amino group equivalent is 0.01 mmol / m ２ When the amino group equivalent is 2.5 mmol / m or more, the adhesion to the resin substrate is excellent. ２ If it is less than this, the laminate is less permeable to water vapor.

[0054] The amount of functional groups in the silane coupling agent contained in the adhesive layer can be determined, for example, from the following theoretical value: Theoretical value: When a coating liquid containing the silane coupling agent (solid content) is applied with a bar coater and dried to form an adhesive layer, the amount is determined by multiplying the wire number of the bar coater by 2.29, multiplying the result by the concentration (= mass of silane coupling agent / mass of coating liquid), and dividing the result by the molecular weight of the silane coupling agent.

[0055] The content of the aminosilane coupling agent contained in the adhesive layer is 0.001 to 1.0 g / m ２ is preferably 0.01 to 0.60 g / m２ More preferably, 0.10 to 0.40 g / m ２ is more preferable.

[0056] The content of the aminosilane coupling agent in the adhesive layer can be determined from the following theoretical value: Theoretical value: When a coating liquid containing the aminosilane coupling agent (solid content) is applied with a bar coater and dried to form an adhesive layer, the content is determined by multiplying the bar coater (gauge) number by 2.29 and multiplying the result by the concentration (= mass of aminosilane coupling agent / mass of coating liquid).

[0057] From the viewpoint of improving adhesive strength, the average thickness of the adhesive layer is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.4 μm or less. From the viewpoint of fully exhibiting adhesiveness, the average thickness of the adhesive layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, and even more preferably 0.1 μm or more.

[0058] In the present disclosure, when a coating liquid containing an aminosilane coupling agent (solid content) is applied with a bar coater and dried to form an adhesive layer, the average thickness of the adhesive layer is determined by multiplying the number of the bar coater (gauge) by 2.29, multiplying the result by the concentration (= mass of aminosilane coupling agent / mass of coating liquid), and then dividing the result by the specific gravity of the silane coupling agent.

[0059] In addition to the aminosilane coupling agent, the adhesive layer may further contain a leveling agent, a solvent, etc. The solvent contained in the coating liquid to dilute the aminosilane coupling agent and improve the coatability when forming the adhesive layer is removed by drying, but may remain in the adhesive layer.

[0060] The solvent may be any solvent capable of dissolving or dispersing a silane coupling agent having a functional group, and examples thereof include aromatic hydrocarbons such as benzene, toluene, and xylene; alicyclic hydrocarbons such as cyclohexane; aliphatic hydrocarbons such as hexane and octane; ethers, ketones, or esters such as diacetone alcohol, diethylene glycol, butyl carbitol, isophorone, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, and ethyl acetate; halogenated hydrocarbons such as dichloromethane and carbon tetrachloride; organic solvents containing two or more functional groups such as dimethylformamide, butyl carbitol acetate, and diethanolamine; and monohydric or polyhydric alcohols such as methanol, ethanol, propanol, 2-propanol, butanol, 2-methyl-1-propanol, and ethylene glycol. The solvents may be used alone or in combination of two or more.

[0061] [Resin substrate] The resin substrate contains at least one resin selected from the group consisting of polyvinyl chloride, olefin resin, acrylic resin, epoxy resin, nylon, polycarbonate, and thermoplastic polyurethane. Among these resins, olefin resin and thermoplastic polyurethane are preferred, and thermoplastic polyurethane is more preferred, from the viewpoint of ease of bonding by hot pressing during production of the laminate.

[0062] The thermoplastic polyurethane may be any of polyester-based thermoplastic polyurethane, polyether-based thermoplastic polyurethane, and polycarbonate-based thermoplastic polyurethane, and from the viewpoint of excellent flexibility, the laminate of the present disclosure preferably contains at least one selected from the group consisting of polyester-based thermoplastic polyurethane and polyether-based thermoplastic polyurethane. From the viewpoints of versatility, cost, and hydrolysis resistance, polyether-based thermoplastic polyurethane is preferred, and from the viewpoint of weather resistance, polycarbonate-based thermoplastic polyurethane is preferred.

[0063] From the viewpoint of the flexibility of the laminate of the present disclosure, the hardness of the thermoplastic polyurethane is preferably 75 to 100, and more preferably 85 to 95. From the viewpoint of the strength of the laminate of the present disclosure, the tensile strength of the thermoplastic polyurethane is preferably 20 to 60 MPa, and more preferably 40 to 50 MPa. From the viewpoint of the flexibility of the laminate of the present disclosure, the tensile elongation of the thermoplastic polyurethane is preferably 300 to 1500%, and more preferably 400 to 1000%. The hardness, tensile strength, and tensile elongation of the thermoplastic polyurethane are values ​​measured in accordance with JIS K7311:1995.

[0064] When the resin substrate contains a thermoplastic polyurethane, the content of the thermoplastic polyurethane in the resin substrate is preferably 70% by mass or more, more preferably 80% by mass or more, and preferably 90% by mass or more, from the viewpoint of the strength and flexibility of the laminate of the present disclosure. The upper limit of the content of the thermoplastic polyurethane in the resin substrate is 100% by mass.

[0065] Examples of olefin resins include ethylene resins and polymers of α-olefins having 3 to 20 carbon atoms, with ethylene resins being preferred. The ethylene resin may be a homocopolymer of ethylene, but from the viewpoint of providing the laminate of the present disclosure with excellent flexibility and sealability, a copolymer of ethylene and a comonomer that is an α-olefin having 3 to 20 carbon atoms is preferred, and a copolymer of ethylene and a comonomer selected from the group consisting of propylene, butene-1, and hexene-1 is preferred. The comonomer content in the ethylene resin affects the melting point and crystallinity of the ethylene resin. The crystallinity affects the hardness of the ethylene resin. Therefore, the comonomer content in the ethylene resin is preferably set so as to obtain the desired melting point and Shore hardness.

[0066] The melting point of the olefin resin is preferably 105°C or higher from the viewpoint of heat resistance of the laminate of the present disclosure. The melting point of the olefin resin is preferably 130°C or lower. When the resin substrate contains an olefin resin, the Shore A hardness of the resin substrate is preferably 60 to 95 from the viewpoint of durability of the laminate of the present disclosure. The Shore A hardness of the resin substrate is a value measured in accordance with JIS K 7215.

[0067] The resin substrate preferably contains an olefin resin foam. In this case, when the laminate of the present disclosure is used as a packing for a cap of a sealed container as described below, sufficient sealing performance is likely to be obtained.

[0068] When the resin substrate contains an olefin resin, the content of the olefin resin in the resin substrate is preferably 70% by mass or more, more preferably 80% by mass or more, and preferably 90% by mass or more, from the viewpoint of the laminate. The upper limit of the content of the olefin resin in the resin substrate is 100% by mass.

[0069] The resin substrate may contain a pigment. One type of pigment may be used alone, or two or more types may be used in combination. As the pigment contained in the resin substrate, a general pigment may be applied, or the pigments exemplified for the fluororesin layer may be applied, and carbon black is preferred.

[0070] The content of the pigment in the resin substrate is preferably 5% by mass or less, more preferably 2% by mass or less, and may be 0% by mass (none contained).

[0071] The resin substrate may be a fiber-containing resin substrate. Examples of fibers contained in the fiber-containing resin substrate include glass fiber and carbon fiber. Examples of resins contained in the fiber-containing resin substrate include thermosetting epoxy resins and room-temperature curing acrylic resins. The resin contained in the fiber-containing resin substrate may be a styrene-based elastomer, saturated polyester resin, etc. A specific example of a fiber-containing resin substrate is Euclear Sheet (registered trademark) manufactured by Unitika Ltd. The laminate of the present disclosure can have high peel strength even when a fiber-containing resin substrate is used.

[0072] When the resin substrate has a softening temperature, the softening temperature is preferably 70 to 200°C, more preferably 110 to 120°C. From the viewpoint of bonding the fluororesin layer and the resin substrate by hot pressing, the difference between the melting temperature of the fluororesin layer and the softening temperature of the resin substrate is preferably within 200°C, more preferably within 150°C. The difference between the melting temperature of the fluororesin layer and the softening temperature of the resin substrate may be 50°C or more, or may be 100°C or more. The softening temperature of the resin substrate can be measured using a high-temperature flow tester described in JIS K7210-1:2014. Approximately 2 g of the resin substrate is filled into a cylinder equipped with a die having a hole with an inner diameter of 1 mm and a length of 10 mm, and a load of 294 N is applied. The temperature is increased from an initial temperature of 100°C at a rate of 6°C / min, and the softening temperature is determined as the temperature at which the resin substrate begins to flow out of the die.

[0073] The average thickness of the resin substrate is not particularly limited and is selected depending on various applications. For example, from the viewpoint of improving adhesive strength, the average thickness of the resin substrate is preferably 0.01 to 10 mm, more preferably 0.05 to 5 mm, and even more preferably 0.1 to 3 mm.

[0074] The average thickness of the resin substrate can be determined by measuring five points on the cross section of the laminate using a microscope and calculating the average value.

[0075] The ratio of the average thickness of the fluororesin layer to the average thickness of the resin substrate is not particularly limited. From the viewpoint of obtaining a laminate having excellent non-stick properties and heat resistance, the ratio of the average thickness of the fluororesin layer to the average thickness of the resin substrate may be 0.001 or more, 0.005 or more, or 0.01 or more. Furthermore, from the viewpoint of obtaining a laminate having excellent flexibility, the ratio of the average thickness of the fluororesin layer to the average thickness of the resin substrate may be 1.0 or less, 0.5 or less, or 0.1 or less.

[0076] [Physical properties of laminate] The peel strength between the fluororesin layer and the resin substrate layer at 23°C is preferably 2.0 N or more, more preferably 5.0 N or more, and even more preferably 10 N or more. The peel strength between the fluororesin layer and the resin substrate layer at 80°C is preferably 2.0 N or more, more preferably 4.0 N or more, and even more preferably 8.5 N or more.

[0077] The ratio of the peel strength at 80°C to the peel strength at 23°C between the fluororesin layer and the resin substrate layer is preferably 0.6 or more, more preferably 0.7 or more, and even more preferably 0.8 or more. The closer the peel strength ratio is to 1, the more the initial peel strength set according to the application of the laminate is maintained even after use at 80°C.

[0078] The peel strength is measured by peeling the fluororesin layer and the resin substrate at a rate of 50 mm / min in accordance with the T-peel test of JIS K6854-3: 1999. The peel strength at 80°C is measured in a thermostatic chamber at 80°C in accordance with the above method.

[0079] From the viewpoint of bending resistance, the elastic modulus is preferably 600 to 1200 MPa, more preferably 800 to 1000 MPa. The elastic modulus is a value measured in accordance with ASTM D638.

[0080] [Layer structure of laminate] Fig. 1 is a cross-sectional schematic diagram showing an example of a laminate of the present disclosure. The laminate 10 of Fig. 1 is formed by providing a fluororesin layer 2, an adhesive layer 4, and a resin substrate 6 in this order. Another layer may be provided on the outer surface of at least one of the fluororesin layer 2 and the resin substrate 6.

[0081] [Applications of Laminate] Applications of the laminate of the present disclosure include belts and chemical-resistant aprons. Other uses of the laminate of the present disclosure include architectural applications (for example, it can be used as a membrane material, a protective film for exterior walls, decorations, a protective film for panels, a protective film for glass, and an adhesive layer for laminated glass), metal-to-metal bonding applications (for example, it can be used to bond a metal plate to a core material, and to bond an aluminum plate to an aluminum honeycomb core or aluminum corrugated), agricultural applications (for example, it can be used as a film for agricultural greenhouses and a protective film for agricultural greenhouses), transportation equipment applications (for example, it can be used to protect the body, headlights, lighting, components, etc. of transportation equipment such as automobiles, aircraft, electric vertical take-off and landing aircraft (eVTOLs), helicopters, drones, ships, etc.), solar cell applications (for example, it can be used as a front sheet, back sheet, film for tab leads, sealing layer, adhesive layer in monocrystalline solar cells, polycrystalline batteries, CIS solar cells, CIGS solar cells, CdTe solar cells, perovskite solar cells (PSCs), dye-sensitized solar cells (DSCs), organic thin-film solar cells (OPVs), GaAs solar cells, etc.), and wind power generation. Applications (for example, it can be used to protect blades, housings, etc.); applications for power generation and charging housings (for example, it can be used as an insulating film in housings); applications for displays (for example, it can be used to protect digital signage, traffic signs, public signs, etc.); applications for protecting plastic films (for example, it can be used to protect plastic molded products and recycled plastics, and to prevent marking films from fading and deterioration); applications for carbon fiber reinforced thermoplastics (CFRTP) and carbon fiber reinforced plastics (CFRP) (for example, it can be used to protect the surface of CFRTP or CFRP. Furthermore, CFRTP or CFRP can be obtained by impregnating carbon fiber with the laminate of the present disclosure); applications for motor insulation in electric vehicles (for example, it can be used as insulating tape or repair tape); applications for batteries (for example, it can be used as an exterior material, film for tab leads, electrodes, and insulating members of batteries. Types of batteries include all-solid-state batteries, semi-solid batteries (for example, gel polymer type semi-solid batteries, clay type semi-solid batteries, liquid added type semi-solid batteries, etc.).), lithium-sulfur batteries (Li-S batteries), lithium ion batteries, manganese iron lithium phosphate batteries (LMFP batteries), lithium iron phosphate batteries (for example, the "M3P battery" manufactured by Contemporary Amperex Technology Co., Ltd. (CATL)), aggregate batteries, all-resin batteries, aluminum-air batteries, etc., but are not limited to these.), semiconductor device component applications (can be used for general components in semiconductor devices that require chemical resistance, pumps, tubes, etc.), semiconductor applications (for example, can be used for release films for sealing resin molds, dicing tapes, and semiconductor heat-resistant tapes. Can also be used to protect semiconductor substrates and wafers.), capacitors, electronic substrates, heat dissipation components, anti-static protective materials, conveyor belts, packing, medical packaging, pharmaceutical packaging, medical instrument packaging, sterilization-resistant packaging, medical tubes, aerospace exterior sheets, food sheet packaging, food belts, food caps, electromagnetic wave shielding materials, heat-shielding sheets, heat-shielding plates, etc. The laminate of the present disclosure, particularly a laminate of the present disclosure in which the resin substrate includes an olefin resin, can be suitably used as a packing for a cap of a sealed container. Specifically, it is useful as a packing used inside a lid to seal the opening of a container body. Examples of sealed containers include sealed containers for storing food or medicine. When the laminate of the present disclosure is used as a packing, it is less likely to be discolored by the contents, such as food or medicine. In addition, a desiccant such as silica gel may be placed inside the lid to maintain the quality of the contents. The laminate of the present disclosure is moderately permeable to water vapor. Therefore, when the laminate of the present disclosure is used as a packing, it is possible to prevent water vapor from entering from the outside while allowing the desiccant to adsorb water vapor, thereby maintaining the quality of the contents.

[0082] <Belt> The belt of the present disclosure includes the laminate of the present disclosure. Examples of the belt include industrial belts such as conveyor belts. Since the decrease in peel strength is suppressed even when used at 80°C, the belt can also be suitably used as a food conveyor belt. Belts such as conveyor belts are used by being placed over a roll-shaped drive pulley and a driven pulley and rotating. If the pulley diameter is small, the belt will be bent with a small curvature. Because the belt of the present disclosure has high peel strength, even when the belt is bent with such a small curvature, peeling between layers is suppressed. Note that PTFE, which is mainly used for belts, has a high elastic modulus and therefore cannot be bent very much. Since each layer of the belt of the present disclosure is composed of the above-mentioned material, it can be bent with a small curvature. From the above, when the belt of the present disclosure is used, a device equipped with a pulley with a small diameter can be constructed, thereby achieving miniaturization of the device.

[0083] <Method for Producing Laminate> One embodiment of the method for producing a laminate according to the present disclosure includes a method of directly stacking and heat-pressing a fluororesin layer containing at least one fluororesin selected from the group consisting of ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer, an adhesive layer containing an aminosilane coupling agent, and a resin substrate containing at least one resin selected from the group consisting of polyvinyl chloride, olefin resin, acrylic resin, epoxy resin, nylon, polycarbonate, and thermoplastic polyurethane in this order to obtain a laminate.

[0084] A method for producing the laminate of the present disclosure includes, for example, applying a coating liquid containing an aminosilane coupling agent to a fluororesin film to form an adhesive layer, laminating a resin substrate on the adhesive layer, and heat-pressing the resulting layer. In this case, the resin substrate melts during heat-pressing and reacts with the aminosilane contained in the adhesive layer, thereby bonding the resin substrate to the fluororesin layer.

[0085] The coating liquid containing the aminosilane coupling agent may be a dispersion or a solution. It is preferable to appropriately adjust the concentration of the coating liquid containing the aminosilane coupling agent, taking into consideration factors such as viscosity. Typically, the solvent is contained in an amount of 10 to 100 parts by mass per 10 parts by mass of the aminosilane coupling agent, but this is not limited thereto. Furthermore, the leveling agent is typically contained in an amount of 0.01 to 0.10 parts by mass per 10 parts by mass of the aminosilane coupling agent, but this is not limited thereto. The contents of other optional components are also appropriately adjusted.

[0086] The method for applying the coating liquid to the fluororesin film is not particularly limited, and examples thereof include various printing methods such as screen printing, spin coating, brush coating, spraying, doctor blade coating, roll coating, inkjet coating, microgravure coating, direct gravure coating, etc. Of these, spin coating, bar coating, and microgravure coating, which allows application in small amounts, are preferred.

[0087] Before applying the coating liquid, at least one of the surface of the fluororesin film facing the adhesive layer and the surface of the resin substrate facing the adhesive layer may be surface-treated in advance. Surface treatment tends to further improve the adhesive strength between the adhesive layer and the fluororesin film, or the adhesive strength between the adhesive layer and the resin substrate. From the viewpoint of improving the peel strength of the laminate, it is preferable to surface-treat the surface of the resin substrate facing the adhesive layer.

[0088] The surface treatment is not particularly limited, and examples thereof include corona discharge treatment, plasma discharge treatment, UV ozone treatment, flame treatment, chemical conversion treatment, primer treatment, etc. A preferred surface treatment method is selected depending on the type of substrate, but from the viewpoint of ease of introduction into industrial processes, corona discharge treatment or plasma discharge treatment is preferred, and corona discharge treatment is more preferred.

[0089] The surface wetting index of the surface-treated fluororesin film is preferably 30 mN / m or more, more preferably 35 mN / m or more, and even more preferably 40 mN / m or more. The upper limit of the wetting tension is not particularly limited, and may be 60 mN / m or less.

[0090] The surface wetting index of the surface-treated resin substrate is preferably 30 mN / m or more, more preferably 40 mN / m or more, and even more preferably 50 mN / m or more. The upper limit of the wetting tension is not particularly limited, and may be 60 mN / m or less.

[0091] The surface wettability index is a value measured in accordance with JIS K6768:1999 using a wettability index reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0092] There are no particular limitations on the ratio of the average thickness of the fluororesin layer before heat pressing to the average thickness of the resin substrate before heat pressing. From the viewpoint of obtaining a laminate excellent in non-stickiness and heat resistance, the ratio of the average thickness of the fluororesin layer before heat pressing to the average thickness of the resin substrate before heat pressing may be 0.001 or more, 0.005 or more, or even 0.01 or more. Furthermore, from the viewpoint of obtaining a laminate excellent in flexibility, the ratio of the average thickness of the fluororesin layer before heat pressing to the average thickness of the resin substrate before heat pressing may be 1.0 or less, 0.5 or less, or even 0.1 or less.

[0093] The heat pressing is preferably performed so that the total thickness of the fluororesin layer, adhesive layer, and resin substrate after the heat pressing is 85% or less, more preferably 60% or less, and even more preferably 50% or less, of the thickness before the heat pressing. When the heat pressing is performed under such conditions, the peel strength of the laminate tends to be further improved. Furthermore, the heat pressing is preferably performed so that the total thickness of the fluororesin layer, adhesive layer, and resin substrate after the heat pressing is 10% or more, more preferably 20% or more, and even more preferably 30% or more, of the thickness before the heat pressing. When the heat pressing is performed under such conditions, overflow of the resin substrate from the laminate tends to be suppressed. The ratio of the total thickness after the heat pressing to the total thickness before the heat pressing can be within the above-mentioned range by adjusting the heat pressing temperature.

[0094] When the resin substrate has a softening temperature, the heat press temperature is preferably equal to or higher than the softening temperature of the resin substrate, and more preferably equal to or higher than the softening temperature of the resin substrate + 20° C., from the viewpoint of improving the peel strength of the laminate. When the resin substrate has a softening temperature, the heat press temperature is preferably equal to or lower than the softening temperature of the resin substrate + 100° C., and more preferably equal to or lower than the softening temperature of the resin substrate + 80° C., from the viewpoint of preventing the resin substrate from flowing too much and protruding from the laminate.

[0095] The heat press temperature is preferably 160 to 190° C., more preferably 170 to 185° C., and even more preferably 175 to 185° C. Even when the laminate of the present disclosure is produced at such a low heat press temperature, the resulting laminate has high peel strength.

[0096] During the heat pressing, it is preferable to use a release film in order to prevent adhesion between the heat pressing machine and the laminate.The release film is preferably a fluororesin film from the viewpoint of conformability and releasability, and more preferably a fluororesin film containing at least one selected from the group consisting of polytetrafluoroethylene (PTFE), ETFE, PFA and FEP.From the viewpoint of conformability such as softness and adhesion, a fluororesin film containing ETFE is preferred, and from the viewpoint of releasability, a fluororesin film containing at least one selected from the group consisting of PTFE, PFA and FEP is preferred.

[0097] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Examples 1 to 3, 5, 6, 8, and 10 are examples, and Examples 4, 7, 9, 11, and 12 are comparative examples.

[0098] [Example 1] (Preparation of Adhesive Film) An adhesive liquid was prepared containing 3.00 mass% of a silane coupling agent containing 3-aminopropyltrimethoxysilane (product name "KBM-903", manufactured by Shin-Etsu Chemical Co., Ltd.), 0.05 mass% of a leveling agent (product name "Surfynol 420", manufactured by Shin-Etsu Chemical Co., Ltd.), and 96.95 mass% of industrial ethanol (product name "Solmix AP-1", manufactured by Japan Alcohol Sales Co., Ltd.). One side of a film (melting temperature: 260°C) of ETFE (TFE unit / E unit / PFBE unit = 54 / 46 / 1.4 (molar ratio), melting point: 260°C, MFR: 10 g / 10 min) with an average thickness of 50 μm was corona discharge treated, and then the adhesive liquid was coated on the corona discharge treated surface by the bar coating method using a No. 5 bar, and the coated fluororesin film was dried at 80°C for 5 seconds. This resulted in a coating thickness of 0.34 μm and a coating amount of 0.34 g / m ２ An adhesive layer of 1.000 ppm was formed on the adhesive film 1, and the surface wettability index after the corona discharge treatment was 42 mN / m. The amount of amino groups in the adhesive layer was measured by the above-mentioned method and found to be 1.92 mmol / m. ２ It was.

[0099] (Preparation of Laminate) The obtained adhesive film 1 was cut into a size of 5 cm x 10 cm. In addition, a carbon black (CB)-containing ester-based thermoplastic polyurethane film (TPU) having an average thickness of 1.05 mm as a resin substrate (product name "DUS501", manufactured by Seedum Co., Ltd., hardness 90, tensile strength 46 MPa, tensile elongation 550%, softening temperature 150 ° C., CB content 2% by mass or less) was cut into a size of 5 cm x 7 cm. In addition, an ETFE film (product name "Fluon (registered trademark) ETFE C-88AXP", manufactured by AGC) as a release film was cut into a size of 10 cm x 15 cm, and two sheets were prepared.

[0100] The adhesive film 1 and the ester-based thermoplastic polyurethane film were stacked together, and the ETFE films serving as the release films were stacked on both outer sides of the film. In this state, a heat press machine (manufactured by Tester Sangyo Co., Ltd.) was used to press the film at a temperature of 160°C for 10 seconds under a surface pressure of 10 kgf / cm. ２The mixture was pressed and heated under the above conditions to obtain a laminate of fluororesin layer / adhesive layer / resin substrate.

[0101] [Examples 2 and 3] Laminates of fluororesin layer / adhesive layer / resin substrate were obtained in the same manner as in Example 1, except that the press temperature was changed to 170°C and 180°C, respectively.

[0102] Example 4 A laminate of fluororesin layer / resin substrate was obtained in the same manner as in Example 1, except that no adhesive layer was provided and the press temperature was set to 180°C.

[0103] [Example 5] A laminate of fluororesin layer / adhesive layer / resin substrate was obtained in the same manner as in Example 1, except that the ester-based thermoplastic polyurethane film (DUS501, manufactured by Seedomm Co., Ltd.) was changed to a polyether-based thermoplastic polyurethane film (product name "DUS220", manufactured by Seedomm Co., Ltd., softening temperature 110 to 120°C) having an average thickness of 0.45 mm, and the press temperature was set to 170°C.

[0104] Example 6 A laminate of fluororesin layer / adhesive layer / resin substrate was obtained in the same manner as in Example 5, except that the press temperature was changed to 180°C.

[0105] Example 7 A laminate of fluororesin layer / resin substrate was obtained in the same manner as in Example 5, except that no adhesive layer was provided and the press temperature was set to 180°C.

[0106] [Example 8] (Preparation of adhesive film) In the same manner as in Example 1, except that ETFE film is changed to PFA (TFE unit / PPVE unit=98.5 / 1.5 (molar ratio), melting point is 305°C, MFR is 4g / 10min) film (melting temperature is 305°C), adhesive film 2 is prepared.

[0107] (Preparation of Laminate) A laminate of fluororesin layer / adhesive layer / resin substrate was obtained in the same manner as in Example 1, except that adhesive film 1 was changed to adhesive film 2 and the press temperature was changed to 180°C.

[0108] Example 9 A laminate of fluororesin layer / resin substrate was obtained in the same manner as in Example 8, except that no adhesive layer was provided.

[0109] [Example 10] (Preparation of adhesive film) Adhesive film 3 was prepared in the same manner as in Example 1, except that the ETFE film was replaced with FEP (TFE unit / HFP unit / PPVE unit = 90 / 9 / 1 (molar ratio), melting point 270 ° C., MFR 10 g / 10 min film (melting temperature 270 ° C.).

[0110] (Preparation of Laminate) A laminate of fluororesin layer / adhesive layer / resin substrate was obtained in the same manner as in Example 1, except that adhesive film 1 was changed to adhesive film 3 and the press temperature was changed to 180°C.

[0111] Example 11 A laminate of fluororesin layer / resin substrate was obtained in the same manner as in Example 10, except that no adhesive layer was provided.

[0112] [Example 12] A fluororesin layer / adhesive layer / resin substrate laminate was obtained in the same manner as in Example 1, except that the adhesive layer was replaced with an acrylic pressure-sensitive adhesive layer, and the method was changed to hand-attaching at room temperature (23°C) without heat pressing. The acrylic pressure-sensitive adhesive layer was formed by applying a composition obtained by mixing a base agent (product name "SK Dyne 2094", manufactured by Soken Chemical & Engineering Co., Ltd.) and a curing agent (product name "M-5A", manufactured by Soken Chemical & Engineering Co., Ltd.) in a ratio of 100:1 to the corona discharge-treated surface of an ETFE film with an applicator, and then removing the dilution solvent in a drying oven. The thickness of the acrylic pressure-sensitive adhesive layer was 25 μm.

[0113] (Evaluation of flowability after hot pressing) The state of the laminate after hot pressing was visually confirmed. The evaluation criteria are as follows: A: The entire resin substrate is melted, and the thickness of the laminate after pressing is reduced to 50% or less of the thickness before pressing. B: Only the surface of the resin substrate is melted. C: Not even the surface of the resin substrate is melted.

[0114] (Evaluation of Peel Strength) The peel strength of the obtained laminate at 23°C was measured by the method described above. In addition, the laminate was placed in a thermostatic chamber at 80°C for 5 minutes, and the peel strength was measured in the thermostatic chamber at 80°C by the method described above. The peel strength measurements at 23°C and 80°C were each performed three times, and the average values ​​were calculated. In addition, the ratio of the average peel strength at 80°C to the average peel strength at 23°C (adhesion strength retention) was calculated.

[0115]

[0116] The laminates of Examples 1 to 3, 5, 6, 8, and 10 all had peel strengths of 2.0 N or more at 23°C, and also had peel strengths of 2.0 N or more at 80°C, and adhesion retention rates of 0.6 or more. In contrast, the laminates of Examples 4, 7, 9, and 11, which did not have an adhesive layer, all had peel strengths of less than 2.0 N at 23°C, and the peel strengths were so low that they could not be measured at 80°C. Furthermore, Example 12, which used an acrylic pressure-sensitive adhesive as the adhesive layer, had a peel strength of 2.0 N or more at 23°C, but the peel strength at 80°C was significantly reduced, and the adhesion retention rate was 0.29.

[0117] Comparing Examples 1 to 3, which used the same fluororesin layer, adhesive layer, and resin substrate, Example 3, in which the thickness of the laminate after heat pressing was reduced to 50% or less of that before heat pressing, had significantly higher peel strengths at 23°C and 80°C than Examples 1 and 2, in which the thickness was more than 50%. Similarly, comparing Examples 5 and 6, Example 6, in which the thickness of the laminate after heat pressing was reduced to 50% or less of that before heat pressing, had significantly higher peel strengths at 23°C and 80°C than Example 5, in which the thickness was more than 50%.

[0118] The disclosures of Japanese Patent Application Nos. 2024-017486 and 2024-076016 are incorporated herein by reference in their entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

[0119] 2: Fluorine resin layer, 4: Adhesive layer, 6: Resin substrate, 10: Laminate

Claims

1. A laminate comprising: a fluororesin layer containing at least one fluororesin selected from the group consisting of ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer; an adhesive layer disposed on one main surface of the fluororesin layer and containing an aminosilane coupling agent; and a resin substrate disposed on the surface of the adhesive layer opposite to the surface on which the fluororesin layer is disposed and containing at least one resin selected from the group consisting of polyvinyl chloride, olefin resin, acrylic resin, epoxy resin, nylon, polycarbonate, and thermoplastic polyurethane.

2. The amount of amino groups contained in the adhesive layer is 0.01 to 2.5 mmol / m ２ The laminate according to claim 1 , 3. The laminate according to claim 1 or 2, wherein the adhesive layer has an average thickness of 1 μm or less.

4. The laminate according to claim 1 or 2, wherein the content of the ethylene-tetrafluoroethylene copolymer in the fluororesin layer is 90% by mass or more.

5. The laminate according to claim 1 or claim 2, wherein the resin substrate contains a pigment.

6. The laminate according to claim 1 or claim 2, wherein the resin substrate comprises at least one selected from the group consisting of ethylene resin, polyester-based thermoplastic polyurethane, and polyether-based thermoplastic polyurethane.

7. The laminate according to claim 1 or 2, wherein the difference between the melting temperature of the fluororesin layer and the softening temperature of the resin substrate is 50 to 200°C.

8. A laminate according to claim 1 or 2, wherein at least one of the surface of the fluororesin layer facing the adhesive layer and the surface of the resin substrate facing the adhesive layer is surface-treated.

9. The laminate according to claim 1 or 2, wherein the peel strength between the fluororesin layer and the resin substrate at 23°C is 2.0 N or more.

10. A laminate according to claim 1 or 2, wherein the ratio of the peel strength at 80°C to the peel strength at 23°C between the fluororesin layer and the resin substrate is 0.6 or more.

11. A belt comprising the laminate of claim 1 or claim 2.

12. A method for manufacturing a laminate, comprising: a fluororesin layer containing at least one fluororesin selected from the group consisting of ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer; an adhesive layer containing an aminosilane coupling agent; and a resin substrate containing at least one resin selected from the group consisting of polyvinyl chloride, olefin resin, acrylic resin, epoxy resin, nylon, polycarbonate, and thermoplastic polyurethane; and then hot pressing the layers in this order to obtain the laminate described in claim 1 or 2.

13. The method for producing a laminate according to claim 12, wherein the heat pressing is carried out so that the total thickness of the fluororesin layer, the adhesive layer, and the resin substrate after the heat pressing is 85% or less of the thickness before the heat pressing.

14. The method for producing a laminate according to claim 12, wherein the temperature of the heat press is equal to or higher than the softening temperature of the resin substrate and equal to or lower than the softening temperature of the resin substrate + 100°C.

15. The method for producing a laminate according to claim 12, wherein the temperature of the heat press is 160 to 190°C.

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