Metal-resin joined body for laminate molding, laminate, and method for producing metal-resin joined body for laminate molding

Abstract

To provide a metal-resin joined body that exhibits favorable adhesion to a metal layer and also favorable adhesion to another resin layer (a polyphenylene sulfide layer).SOLUTION: A metal-resin joined body for laminate molding comprises a resin film laminated on a metal layer, wherein at least one surface layer of the resin film comprises a resin having a polyphenylene sulfide skeleton, with a melting peak top temperature in a range of 220°C to 270°C as measured by differential scanning calorimetry (DSC).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a metal-resin joined body for laminate molding, a laminate, and a method for producing a metal-resin joined body for laminate molding. [Background technology]

[0002] In recent years, environmental regulations and global warming have led to an increasing demand for improved fuel efficiency and lighter weight in automobiles. To reduce the weight of automobiles, the use of high-strength steel materials and light metals such as aluminum has been considered. The use of resin materials to reduce weight has also been considered, and composite materials of metal and resin are being used in automobile parts.

[0003] For example, Patent Document 1 discloses the use of a PPS sheet as an electrical insulating material, and discloses a laminate in which a polyphenylene sulfide layer (A) and a polyphenylene sulfide alloy layer (B) are laminated. Furthermore, various proposals have been made regarding methods for bonding metal and resin in metal-resin composites. For example, Patent Document 2 discloses a laminate including a resin layer containing a polyarylene sulfide resin and a metal layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-40962 [Patent Document 2] Japanese Patent Publication No. 2023-15622 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, Patent Document 1 proposes a resin film having an alloy structure of polyphenylene sulfide and an olefin copolymer, but while the tensile strength of the film is good, the adhesion to the metal layer is insufficient. Also, Patent Document 2 has a problem with adhesion to the metal, and in order to improve the adhesion, it is necessary to improve the manufacturing process, such as by increasing the temperature during heat pressing.

[0006] When a bonded body formed by laminating a metal layer and a resin layer is used as an automobile part or the like, another resin layer may be further laminated thereon in some cases, and therefore the metal-resin bonded body is required to have good adhesion to the other resin layer.

[0007] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a metal-resin bonded body that has good adhesion to a metal layer and also good adhesion to another resin layer (polyphenylene sulfide layer). [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by employing a metal-resin bonded body in which a resin film having a specific configuration is bonded to a metal layer, and have completed the present invention as described below. That is, the present invention provides the following [1] to

[13] . [1] A metal layer and a resin layer laminated on the metal layer, A metal-resin bonded body for laminate molding, wherein the resin layer contains a resin having a polyphenylene sulfide skeleton, the melting peak top temperature of which is in the range of 220 to 270°C as measured by a differential scanning calorimeter (DSC). [2] The metal-resin joined body for laminate molding according to [1], wherein the 180° peel strength of the resin layer from the metal layer is 1.0 N / 20 mm or more when rolled at a rolling reduction of 50 to 60%. [3] The metal-resin bonded body for laminate molding according to [1] or [2], wherein the resin layer has a thickness of 5 to 200 μm. [4] The metal-resin bonded body for laminate molding according to any one of [1] to [3], wherein the metal layer contains aluminum or an aluminum alloy. [5] The metal-resin bonded body for laminate molding according to any one of [1] to [3], wherein the metal layer contains copper or a copper alloy. [6] The metal-resin bonded body for laminate molding according to any one of [1] to [5], wherein the thickness of the metal layer is 0.05 to 2.0 mm. [7] The resin layer has a multi-layer structure; The metal-resin bonded body for laminate molding according to any one of [1] to [6], wherein the resin layer disposed on the metal layer side contains a resin having a polyphenylene sulfide skeleton, the melting peak top temperature of which, as measured by a differential scanning calorimeter (DSC), is in the range of 220°C to 270°C. [8] The metal-resin bonded body for laminate molding according to any one of [1] to [7], which is for use in automobile parts. [9] The metal-resin bonded body for laminate molding according to [8], which is for a bus bar.

[10] A laminate obtained by laminating another resin layer on the resin layer of the metal-resin bonded product for laminate molding according to any one of [1] to [9].

[11] The laminate according to

[10] , wherein the other resin layer is a polyphenylene sulfide layer.

[12] A method for producing a metal-resin bonded body for laminate molding according to any one of [1] to [9], A method for producing a metal-resin joined body for laminate molding, comprising a step of joining a metal layer and a resin layer directly or via another layer.

[13] A method for producing a metal-resin joined body for laminate molding according to

[12] , comprising: step 1 of surface-treating the surface of at least one selected from the metal layer and the resin layer with a silane coupling agent treatment liquid; and step 2 of laminating an untreated resin layer on the surface of the surface-treated metal layer, or laminating an untreated metal layer on the surface-treated resin layer, and bonding them by thermocompression bonding. [Effects of the Invention]

[0009] According to the present invention, a metal-resin bonded body can be obtained which has good adhesion between a metal layer and a resin layer, and also has good adhesion to another resin layer (polyphenylene sulfide layer). DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, an example of an embodiment of the present invention will be described. However, the present invention is not limited to the embodiment described below, and can be implemented with any modifications within the scope of the gist of the present invention. In this specification, when "X to Y" (X and Y are any numbers) is used, unless otherwise specified, it means "X or more and Y or less," and also includes "preferably greater than X" or "preferably less than Y." Furthermore, when "X or more" (X is any number) or "Y or less" (Y is any number), it also includes the meaning "preferably greater than X" or "preferably less than Y." In the following description, the terms "film" and "sheet" are not clearly distinguished from each other, and the term "film" includes the term "sheet," and the term "sheet" includes the term "film."

[0011] <Metal-resin bonded body> This embodiment relates to a metal-resin bonded body for laminate molding (hereinafter also simply referred to as a metal-resin bonded body) having a metal layer and a resin layer laminated on the metal layer. In this metal-resin bonded body of this embodiment, the resin layer contains a resin having a polyphenylene sulfide skeleton whose melting peak top temperature, as measured by a differential scanning calorimeter (DSC), is in the range of 220 to 270°C.

[0012] The metal-resin bonded body of this embodiment is a metal-resin bonded body for laminate molding. In this specification, "for laminate molding" includes both an application for further laminating metal-resin bonded bodies having a metal layer and a resin layer to each other and an application for laminating a metal-resin bonded body having a metal layer and a resin layer to another adherend. When laminating the metal-resin bonded body to another adherend, examples of the other adherend include a resin injection-molded product and a metal molded product.

[0013] The metal-resin bonded body of this embodiment is a metal-resin bonded body having at least one metal layer and one resin layer. The metal-resin bonded body of this embodiment has excellent adhesion between the metal layer and the resin layer, and the resin layer has good conformability to the metal layer, making it applicable to, for example, a lamination molding process that involves deformation, such as a rolling process. Therefore, the metal-resin bonded body of this embodiment is particularly suitable for use in automobile parts (e.g., automobile interior materials, automobile exterior materials, bus bars). When the metal-resin bonded body is used for automobile parts, another resin layer (polyphenylene sulfide layer) may be attached, and the metal-resin bonded body of this embodiment can exhibit good adhesion to the other resin layer (polyphenylene sulfide layer).

[0014] Furthermore, the metal-resin bonded body of this embodiment has excellent adhesion between the metal layer and the resin layer, and the resin layer has good conformability to the metal layer, so that the metal-resin bonded body also has excellent processability. For example, even when the metal-resin bonded body is subjected to severe deformation such as rolling, bending, or pressing, the resin layer conforms to the metal layer, so that the metal-resin bonded body can exhibit good processability.

[0015] When the metal-resin bonded body of this embodiment is rolled to a rolling reduction of 50 to 60%, the 180° peel strength of the resin layer relative to the metal layer is preferably 1.0 N / 20 mm or more, more preferably 1.5 N / 20 mm or more, and even more preferably 2.0 N / 20 mm or more. The upper limit of the 180° peel strength of the resin layer relative to the metal layer when rolled to a rolling reduction of 50 to 60% is not particularly limited, but is preferably, for example, 10 N / 20 mm or less. When a rolling process is included, the resin layer needs to conform to the metal layer as it is stretched thin. A peel strength at a rolling reduction of 50 to 60% within the above range indicates good adhesion between the metal layer and the resin layer even under harsh conditions, and excellent conformability of the resin layer. Therefore, the metal-resin bonded body of this embodiment is also applicable to laminate molding applications that involve deformation such as a rolling process. The rolling reduction when measuring the 180° peel strength can be adjusted appropriately depending on the type of metal layer, but the specific measurement method described in the Examples can be adopted.

[0016] [Resin layer] The metal-resin bonded body of the present embodiment has a resin layer, and the resin layer contains a resin having a polyphenylene sulfide skeleton whose melting peak top temperature, as measured by a differential scanning calorimeter (DSC), is in the range of 220 to 270° C. When the resin layer contains a resin having a polyphenylene sulfide skeleton satisfying the above conditions, the adhesion between the metal layer and the resin layer can be more effectively improved, and the conformability of the resin layer to the metal layer can be more effectively improved.

[0017] In this specification, the resin layer refers to a layer that is in contact with the metal layer or a layer that is laminated on the metal layer via a primer layer, etc. In this way, by containing a resin having a polyphenylene sulfide skeleton and having a melting peak top temperature in the range of 220 to 270°C in the resin layer that is laminated directly or indirectly on the metal layer, the adhesion between the metal layer and the resin layer can be more effectively improved, and the conformability of the resin layer to the metal layer can be more effectively improved.

[0018] The melt viscosity of the resin having a polyphenylene sulfide skeleton is preferably 250 Pa·s or more and 2000 Pa·s or less.

[0019] The thickness (total thickness) of the resin layer is preferably 5 μm or more, more preferably 7 μm or more. On the other hand, the upper limit is 200 μm or less, preferably 100 μm or less, more preferably 80 μm or less, and particularly preferably 60 μm or less, taking into consideration ease of handling. By keeping the thickness of the resin layer within the above range, the adhesion between the metal layer and the resin layer can be more effectively improved.

[0020] In the metal-resin bonded body of this embodiment, the resin layer may be a single layer or may have a multilayer structure. When the resin layer has a multilayer structure, the layer disposed on the metal layer side contains a resin having a polyphenylene sulfide skeleton whose melting peak top temperature measured by a differential scanning calorimeter (DSC) is in the range of 220°C to 270°C. This can improve the adhesion between the resin layer and the metal.

[0021] When the resin layer has a multilayer structure, the resin layer may be, for example, a one-type two-layer structure consisting of two layers (A / A), a two-type two-layer structure consisting of two layers (A / B), a two-type three-layer structure consisting of three layers (A / B / A), or a three-type three-layer structure consisting of three layers (A / B / C). Below, each component in the two-type two-layer structure consisting of two layers (A / B) will be described in detail. Note that when the resin layer is a single layer, the resin layer is composed only of resin layer A.

[0022] <Resin layer A> Resin layer A is a layer of the resin layer that is arranged on the metal layer side, and contains a resin (hereinafter also referred to as polyphenylene sulfide resin) having a polyphenylene sulfide skeleton whose melting peak top temperature measured by a differential scanning calorimetry (DSC) is in the range of 220°C to 270°C.

[0023] Polyphenylene sulfide resin has a repeating unit represented by the following structural formula (1): The repeating unit has a sulfur atom attached to one benzene ring. n is an integer of 2 or more, preferably 80 to 1000, more preferably 100 to 700, and even more preferably 150 to 500. [ka]

[0024] Polyphenylene sulfide resins having a substantially linear structure are preferred from the viewpoints of film formability, physical properties, etc. However, within the range that does not substantially deteriorate these physical properties, for example, a polymerized cross-linked product obtained by using an effective amount of a cross-linking agent (e.g., trihalobenzene) during polymerization, or a thermally cross-linked product obtained by cross-linking a polymer by heat treatment in the presence of oxygen, etc., can also be used.

[0025] The polyphenylene sulfide resin is also preferably a modified polyphenylene sulfide. Examples of the modified polyphenylene sulfide include modified polyphenylene sulfides obtained by graft-reacting unmodified polyphenylene sulfide with a modifier having both a double bond and a reactive functional group, such as glycidyl methacrylate, glycidyl acrylate, acrylic acid, maleic anhydride, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, acrylamide, N-[4-(2,3-epoxypropoxy)-3,5-dimethylphenylmethyl]acrylamide, or vinyltrimethoxysilane, to introduce functional groups such as epoxy groups, carboxyl groups, acid anhydride groups, alcoholic hydroxyl groups, amino groups, and alkoxysilyl groups.

[0026] The modified polyphenylene sulfide may be one obtained by melt-reacting a modifying agent having both a disulfide group and a reactive functional group, such as 4,4'-dithiodi(n-butyl acid), dithiodiacetic acid, dithiodianiline, or dithiodibenzoic acid, to introduce functional groups such as carboxyl groups or amino groups. The modified polyphenylene sulfide may also be one obtained by melt-reacting a modifying agent having both a mercapto group and a reactive functional group, such as thiomalic acid, mercaptoacetic acid, mercaptopropionic acid, or aminothiophenolmercaptobenzoic acid, to introduce functional groups such as carboxyl groups or amino groups. Modified polyphenylene sulfide may also be one obtained by reacting a silane coupling agent, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, or γ-aminopropyltriethoxysilane.

[0027] The polyphenylene sulfide resin constituting the resin layer A is also preferably a copolymerized polyphenylene sulfide. Examples of copolymerized polyphenylene sulfide include copolymerized polyphenylene sulfide produced by copolymerizing functional group-containing monomers, such as copolymerized polyphenylene sulfide containing amino groups, hydroxyl groups, and carboxyl groups. Furthermore, modified copolymerized polyphenylene sulfide can be used, which is obtained by melt-reacting a modifier having both a sulfonic acid group or a nitro group and a reactive functional group, such as 4-hydroxy-1-naphthalenesulfonic acid, 3-amino-4-hydroxybenzenesulfonic acid, 4-aminobenzenesulfonic acid, 3-sulfobenzoic acid, 4-sulfophthalic acid, 4-nitronaphthalene-1,8-dicarboxylic anhydride, 4-nitrophthalic anhydride, or nitrobenzoic acid, to introduce functional groups such as carboxyl groups, acid anhydride groups, hydroxyl groups, and amino groups. For example, by changing the chemical structure of a polyphenylene sulfide precursor and copolymerizing it with a normal polyphenylene sulfide precursor, good physical properties such as adhesion to a metal layer can be obtained, which is more preferable.

[0028] When polyphenylene sulfide is blended with another resin component for the purpose of modifying the resin layer A, the type of resin may be any, and examples thereof include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polymethylpentene, polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyacetal, aliphatic polyamide, polymethyl methacrylate, polycarbonate, ABS, aromatic polyamide, polyarylate, polyetherimide, polyamideimide, polysulfone, polyethersulfone, polyphenylene sulfone, polyaryletherketone, liquid crystal polymer, copolymers thereof, and mixtures thereof. Among these, polycarbonate, polyphenylene ether, polyethersulfone, polyphenylene sulfone, polyetherimide, and polysulfone are preferred, with polyphenylene ether being more preferred, particularly from the viewpoint of improving adhesion to metal layers and to resins (polyphenylene sulfide).

[0029] The crystalline melting temperature (Tm) of the resin layer A is preferably 270° C. or lower, more preferably 265° C. or lower, and particularly preferably 260° C. or lower. The lower limit of the crystalline melting temperature (Tm) of the resin layer A is not particularly limited, but is preferably 230° C. or higher, for example. By setting the crystalline melting temperature (Tm) of the resin layer A within the above range, the adhesion between the metal layer and the resin layer can be more effectively improved.

[0030] The thickness of the resin layer A is preferably 5 μm or more, more preferably 7 μm or more. On the other hand, the upper limit is 200 μm or less, preferably 80 μm or less, and more preferably 60 μm or less, taking into consideration ease of handling. By keeping the thickness of the resin layer A within the above range, the adhesion between the metal layer and the resin layer can be more effectively improved.

[0031] <Resin layer B> Resin layer B is a layer disposed on the opposite side of the resin layer from the metal layer side. Resin layer B contains a resin having a polyphenylene sulfide skeleton as a main component (50% by mass or more), and the melt viscosity of the resin having a polyphenylene sulfide skeleton is preferably 250 Pa s or more and 2000 Pa s or less.

[0032] Polyphenylene sulfide resin has a repeating unit represented by the following structural formula (1): The repeating unit has a sulfur atom attached to one benzene ring. n is an integer of 2 or more, preferably 80 to 1000, more preferably 100 to 700, and even more preferably 150 to 500. [ka]

[0033] Polyphenylene sulfide resins having a substantially linear structure are preferred from the viewpoints of film formability, physical properties, etc. However, within the range that does not substantially deteriorate these physical properties, for example, a polymerized cross-linked product obtained by using an effective amount of a cross-linking agent (e.g., trihalobenzene) during polymerization, or a thermally cross-linked product obtained by cross-linking a polymer by heat treatment in the presence of oxygen, etc., can also be used.

[0034] The polyphenylene sulfide resin contained in the resin layer B may be a modified polyphenylene sulfide, but in this embodiment, the polyphenylene sulfide resin contained in the resin layer B is preferably an unmodified polyphenylene sulfide.

[0035] The content of the polyphenylene sulfide resin is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, relative to the total mass of the resin layer B. The content of the polyphenylene sulfide resin may be 100% by mass, relative to the total mass of the resin layer B.

[0036] The thickness of the resin layer B is preferably 5 μm or more, more preferably 7 μm or more, and even more preferably 10 μm or more. The thickness of the resin layer B is preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less. By setting the thickness of the resin layer B within the above range, the handleability of the resin film forming the resin layer can be improved.

[0037] (additives) The resin layers (resin layer A and resin layer B) may contain various additives such as heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, dyes, fillers, etc., within the scope of the present invention. The content of the additives is preferably 5% by mass or less relative to the total mass of the resin layer.

[0038] [Metal layer] The metal-resin bonded body of this embodiment has a metal layer. The metal constituting the metal layer can be a commercially available product and is not particularly limited. Specific examples include iron, steel, tinplate, tin-free steel (TFS), copper, aluminum, stainless steel, and alloys containing any of these as a single component.

[0039] From the viewpoint of corrosion resistance and adhesion to the resin layer, the surface of the metal layer may be plated with one or more metals, or may be provided with a commonly used inorganic oxide coating, such as a chemical conversion coating represented by chromic acid treatment, phosphate treatment, chromic acid / phosphate treatment, electrolytic chromic acid treatment, chromate treatment, etc. Furthermore, the metal layer may be subjected to other treatments such as electrochemical treatment and physical treatment.

[0040] From the viewpoint of electrical properties, etc., it is preferable that the metal layer contains aluminum or an aluminum alloy, or copper or a copper alloy. In particular, it is preferable that the metal layer contains aluminum or an aluminum alloy, in consideration of processability, cost, environmental friendliness, lightweight, etc.

[0041] Specific examples of aluminum alloys include non-heat-treatable or heat-treatable aluminum alloys specified by or conforming to JIS. Non-heat-treatable aluminum alloys include pure aluminum (1000 series), Al-Mn alloys (3000 series), Al-Si alloys (4000 series), and Al-Mg alloys (5000 series). Heat-treatable aluminum alloys include Al-Cu-Mg alloys (2000 series), Al-Mg-Si alloys (6000 series), and Al-Zn-Mg alloys (7000 series).

[0042] Specific examples of copper or copper alloys include, but are not limited to, high-purity copper such as tough pitch copper, oxygen-free copper, and phosphorus-deoxidized copper, as well as copper alloys such as brass, phosphor bronze, Cu-Fe alloys, Cu-Fe-P alloys, and Cu-Ni-Si alloys. Among these, copper or copper alloys with a copper purity of 99.90% or more are preferred, particularly from the viewpoint of further improving electrical properties.

[0043] The thickness of the metal layer is preferably 0.05 mm or more, more preferably 0.1 mm or more. The thickness of the metal layer is preferably 3.0 mm or less, more preferably 2.5 mm or less, even more preferably 2.0 mm or less, even more preferably 1.5 mm or less, and particularly preferably 1.0 mm or less. By setting the thickness of the metal layer within the above range, formability can be more effectively improved.

[0044] [Method of manufacturing a metal-resin bonded body] The metal-resin bonded body is manufactured by forming the aforementioned resin layer on at least one surface of a metal layer. The manufacturing method is not particularly limited, but examples include a method in which a molten resin, which is a resin layer-forming composition, is extruded into a film on the surface of the metal layer to form a laminate, and a method in which a pre-formed resin film for forming the resin layer is laminated onto the metal layer. Regarding the manufacturing method of the resin film for forming the resin layer, a general molding method can be used. For example, the resin film can be molded into a desired shape, such as a film or a sheet, by extrusion molding, lamination molding, melt casting, or press molding. The apparatus and processing conditions for each molding method are not particularly limited, and known methods can be used. Furthermore, to improve adhesion, the surface of the resin layer may be subjected to various surface treatments, such as corona treatment or painting, or metal vapor deposition.

[0045] In particular, the method for producing a metal-resin bonded body according to this embodiment preferably includes a step of bonding a metal layer and a resin layer directly or via another layer. The step of bonding a metal layer and a resin layer is not particularly limited, but thermocompression bonding is preferably performed by passing the resin layer and the metal layer between a pair of heating rolls (pressure bonding rolls). The temperatures of the pair of heating rolls may be the same or different. Alternatively, bonding can be performed by overlaying a resin layer on a metal layer preheated to a predetermined temperature and then performing pressure bonding at a temperature equal to or higher than the melting point of the resin constituting the resin layer. The width between the pair of heating rolls can be adjusted appropriately depending on the thickness of the laminate. The temperature during thermocompression bonding is preferably at least 3°C ​​above the melting point of the resin constituting the resin layer, more preferably at least 5°C above the melting point of the resin, and even more preferably at least 10°C above the melting point of the resin. This allows the resin layer to be sufficiently melted, thereby enhancing the adhesive strength with the metal layer.

[0046] The metal layer and the resin layer may be directly laminated by thermocompression bonding. In such a case, there is no need to provide an adhesive layer or the like between the metal layer and the resin layer, and therefore the metal-resin bonded body can be made thinner and lighter. On the other hand, when the metal layer and the resin layer are laminated via another layer, the other layer may be an adhesive layer such as a hot-melt adhesive or a primer, or a reactive adhesive layer such as a urethane adhesive or an acrylic adhesive.

[0047] The metal layer may be subjected to a primer treatment. By further applying a primer treatment to the surface of the metal layer, adhesion to the resin layer can be further improved. Examples of primers used in the primer treatment include silane coupling agents having functional groups such as epoxy groups, amino groups, and acrylic groups, titanium coupling agents, and various epoxy-based, urethane-based, and acrylic-based coating agents. From the viewpoint of adhesion to the resin layer, silane coupling agents are preferred.

[0048] The method for producing a metal-resin bonded body may include Step 1 of surface-treating the surface of at least one selected from the metal layer and the resin layer with a silane coupling agent treatment liquid. In this case, it is preferable to include Step 2 of laminating an untreated resin layer on the surface of the metal layer surface-treated in Step 1, or laminating an untreated metal layer on the resin layer surface-treated in Step 1, and bonding them by thermocompression bonding. In Step 1, it is preferable to surface-treat the surface of at least one selected from the metal layer and the resin layer with a silane coupling agent treatment liquid, and in particular, it is preferable to surface-treat the surface of the metal layer with a silane coupling agent treatment liquid.

[0049] The silane coupling agent treatment liquid used in step 1 contains a silane coupling agent. The silane coupling agent is an organosilicon compound having an organic functional group and a hydrolyzable group such as an alkoxy group in one molecule. For example, epoxy group-containing compounds such as 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; vinyl group-containing compounds such as vinyltrimethoxysilane and vinyltriethoxysilane; styryl group-containing compounds such as p-styryltrimethoxysilane and p-styryltriethoxysilane; (meth)acrylic group-containing compounds such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-2-(aminoethyl)- Examples of suitable compounds include amino group-containing compounds such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyltriethoxysilane; isocyanurate group-containing compounds such as tris(trimethoxysilylpropyl)isocyanurate and tris(triethoxysilylpropyl)isocyanurate; and mercapto group-containing compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane. Among the above compounds, amino group-containing silane coupling agents are more preferred from the viewpoint of achieving both adhesion to the metal layer and adhesion to the resin layer. The silane coupling agents may be used alone or in combination of two or more.

[0050] The silane coupling agent may be applied to the metal layer surface as a liquid coating solution and dried as necessary. The silane coupling agent treatment solution is preferably prepared as a coating solution by diluting it with a solvent. The silane coupling agent treatment solution may be dissolved in a solvent or dispersed in a solvent. The content of the silane coupling agent contained in the silane coupling agent treatment solution is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, based on the total mass of the silane coupling agent treatment solution. Furthermore, the content of the silane coupling agent is preferably 1% by mass or less, more preferably 0.8% by mass or less, and even more preferably 0.5% by mass or less, based on the total mass of the silane coupling agent treatment solution.

[0051] The solvent contained in the silane coupling agent treatment liquid is not particularly limited, and either water or an organic solvent may be used. From the viewpoint of environmental protection, it is preferable to use an aqueous coating liquid containing water as the solvent. The aqueous coating liquid may contain a small amount of organic solvent. The specific amount of organic solvent should be less than that of water on a mass basis, and is preferably, for example, less than 30 mass % of the total mass of the solvent, more preferably less than 20 mass %, and even more preferably less than 10 mass %.

[0052] Examples of organic solvents used in combination with water include alcohols such as ethanol, isopropanol, ethylene glycol, and glycerin; ethers such as ethyl cellosolve, t-butyl cellosolve, propylene glycol monomethyl ether, and tetrahydrofuran; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; and amines such as dimethylethanolamine. These can be used alone or in combination. By appropriately selecting and adding these organic solvents to the aqueous coating solution as needed, the stability and coatability of the coating solution can sometimes be improved.

[0053] Examples of a method for applying the silane coupling agent treatment liquid to the surface of the metal layer include conventionally known application methods such as air doctor coating, blade coating, rod coating, bar coating, knife coating, squeeze coating, impregnation coating, reverse roll coating, transfer roll coating, gravure coating, kiss roll coating, cast coating, spray coating, curtain coating, calendar coating, and extrusion coating.

[0054] Furthermore, in order to improve the coatability or adhesion of the silane coupling agent treatment liquid to the metal layer surface, the metal layer surface may be subjected to a surface treatment such as chemical treatment, corona discharge treatment, plasma treatment, ozone treatment, chemical treatment, or solvent treatment before the coating liquid is applied.

[0055] In this embodiment, the amount of the silane coupling agent treatment liquid to be applied is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 15 μm or more in terms of the thickness of the wet coating, and is preferably 30 μm or less, more preferably 20 μm or less in terms of the thickness of the wet coating.

[0056] After the application of the silane coupling agent treatment liquid, a drying step is preferably performed. The drying step is preferably a step of removing the solvent contained in the silane coupling agent treatment liquid. By removing the solvent from the silane coupling agent treatment liquid, the surface of the metal layer or resin layer is treated with the silane coupling agent. The silane coupling agent chemically bonds the metal layer and the resin layer.

[0057] In step 2, an untreated resin layer is laminated on the surface of the metal layer that has been surface-treated in step 1, or an untreated metal layer is laminated on the resin layer that has been surface-treated in step 1, and the two layers are bonded by thermocompression. In particular, step 2 is preferably a step of laminating an untreated resin layer on the surface of the metal layer that has been surface-treated in step 1, and then bonding them by thermocompression. In step 2, a set of laminated metal layers / resin layers may be laminated, and then multiple sheets (multiple sets) may be laminated by thermocompression, or multiple metal layers and multiple resin layers (multiple sets) may be laminated from the beginning. In step 2, it is preferable to laminate the metal layer / resin layer laminate so that the metal layers and resin layers are alternately laminated. However, for example, the resin layers may be laminated so that the exposed surface at the end of the thickness direction is the metal layer, and the resin layers are in contact with each other.

[0058] In the thermocompression bonding process, it is preferable to perform thermocompression bonding by passing one or more pairs of laminates between a pair of heated rolls (compression rolls). The temperatures of the pair of heated rolls may be the same or different. Alternatively, a resin layer may be superimposed on a metal layer preheated to a predetermined temperature, and then pressure-bonded at a temperature equal to or higher than the melting point of the resin constituting the resin layer. The width between the pair of heated rolls can be appropriately adjusted depending on the thickness of the laminate. In this embodiment, the thermocompression bonding process (silane bonding) may be a pressure bonding process using rolls or a heat press bonding process. Alternatively, the thermocompression bonding process using rolls and the above-mentioned heat press bonding process may be combined. For example, after a pair of laminates in which a metal layer / resin layer is laminated is produced, the metal layer and the resin layer may be laminated and subjected to the heat press bonding process.

[0059] [How to use metal-resin bonded bodies] The metal-resin bonded body described above is particularly preferably used for automobile parts (for example, automobile interior materials, automobile exterior materials, and bus bars). The resin layer constituting the metal-resin bonded body of this embodiment may be bonded to another resin layer (for example, an injection-molded resin product). This embodiment may also relate to a laminate obtained by laminating another resin layer on the resin layer of the metal-resin bonded body. In this case, the other resin layer is not particularly limited, but is preferably a polyphenylene sulfide layer from the viewpoint of heat resistance, strength, and the like. [Example]

[0060] The present invention will now be described in more detail with reference to examples, although the present invention is not limited to the examples described below.

[0061] <Evaluation method> The methods for measuring and evaluating various physical properties and characteristics are as follows.

[0062] (1) Crystal melting temperature (Tm) of the resin layer Using a PerkinElmer differential scanning calorimeter "DSC8500," the resin layer was heated in the temperature range of 30 to 300°C at a heating rate of 10°C / min, and the crystalline melting temperature (Tm) of the resin layer was determined from the peak top temperature of the melting peak of the detected DSC curve.

[0063] (2) Peel strength of resin layer against metal layer A rolled sample was prepared by rolling the metal-resin bonded body at a rolling reduction of 60% when the metal layer was aluminum and at a rolling reduction of 50% when the metal layer was copper. The rolling reduction was calculated by dividing the "difference in thickness of the bonded body before and after rolling" by the "original thickness of the bonded body," and the thickness was measured using a micrometer. Two cuts were made with a cutter blade to allow the resin layer to be peeled off over a width of 20 mm, and a 180° peel test piece was prepared. The peel strength (N / 20 mm) was then determined by a 180° peel test at a tensile speed of 50 mm / min. In the comparative examples, when the metal layer and the resin layer could not be bonded, the result was recorded as "not bonded."

[0064] (3) Adhesion to polyphenylene sulfide A polyphenylene sulfide film was placed on the resin layer side of the A4-sized metal-resin bonded body obtained in the examples, and the resulting body was fused by passing it through a roll heated to 290°C twice. A polyimide film was partially sandwiched between the two films, preventing the edges from adhering and providing a gripping area for the peel test. A 180° peel test was then performed at a width of 10 mm to evaluate the adhesion between the resin layer of the metal-resin bonded body and the polyphenylene sulfide film. If the polyphenylene sulfide film broke without peeling at the fused portion, the resin layer of the metal-resin bonded body and the polyphenylene sulfide film had sufficient adhesion, and the result was evaluated as "Good." If the resin layer of the metal-resin bonded body and the polyphenylene sulfide film were not fused, the result was evaluated as "Poor." In the comparative examples, if the metal-resin bonded body itself could not be produced, the result was evaluated as "-."

[0065] (4) Conformity of metal and resin layers No. 5 test pieces were prepared from the metal-resin bonded bodies in accordance with JIS Z 2241: 2011, and tensile tests were performed in the MD in accordance with JIS Z 2241: 2011. If peeling did not occur between the metal layer and the resin layer until the test piece broke, the conformability was judged to be good and was evaluated as "○", and if no evaluation was made, it was evaluated as "-".

[0066] The raw materials used in each of the examples and comparative examples are as follows. <Resin layer> (a) Copolymerized polyphenylene sulfide film Thickness: 38 μm Melting peak top temperature: 252℃ (b) Two-layer film consisting of (a) and a polyphenylene sulfide resin layer laminated together Total thickness: 38 μm (a) Layer thickness: 7 μm Polyphenylene sulfide resin layer thickness: 31 μm Melting peak top temperature of polyphenylene sulfide resin layer: 289°C (c) 6-Nylon film Thickness: 20 μm Melting peak top temperature: 219℃ (d) Polyphenylene sulfide film Thickness: 50 μm Melting peak top temperature: 286℃

[0067] <Metal layer> (e) Aluminum plate material A1100P―H16 Thickness: 0.3mm Chromate phosphate treated material (f) Copper plate material C1020P-1 / 4H Thickness: 0.1mm (g)Copper plate material C1020P-1 / 2H Thickness: 1mm

[0068] [Example 1] Hydrolyzed 3-aminopropyltriethoxysilane was mixed with water and ethanol to a concentration of 0.15 wt%, and then coated with a #9 bar coater onto one surface of (e), which had been cut to A4 size to serve as the metal layer, and the water was dried by heating in an oven at 130°C for 1.5 minutes. (a) was placed on top of the solution-coated metal layer as the resin layer, and one side was thermocompressed between rolls set at 250°C, after which it was passed through a heating furnace set at 400°C for 40 seconds to obtain a metal-resin bonded body.

[0069] [Example 2] A metal-resin bonded body was obtained in the same manner as in Example 1, except that in Example 1, the type of resin layer was changed to (b), the two types of two layers were stacked so that the metal layer side was the (a) layer, and the roll temperature setting was changed to 260°C.

[0070] [Example 3] A metal-resin bonded body was obtained in the same manner as in Example 2, except that the solution containing the hydrolyzate of 3-aminopropyltriethoxysilane was not applied to the surface of (e).

[0071] [Example 4] Hydrolyzed 3-aminopropyltriethoxysilane was mixed with water and ethanol to a concentration of 0.15 wt%, and then coated with a #9 bar coater on one surface of (f), which had been cut to a size of 300 mm long and 155 mm wide, as a metal layer. The water was then dried by heating in an oven at 130°C for 1.5 minutes. After annealing (f) with the coated solution in a heating furnace set to 290°C for 18 seconds, (a) was placed on the surface (coated surface) of (f) as a resin layer, and one side was thermocompressed between rolls set to 250°C. After passing through a heating furnace set to 400°C for 40 seconds, a metal-resin bonded body was obtained.

[0072] [Example 5] (f) cut into an A4 size metal layer was annealed in a heating furnace set at 290°C for 18 seconds, and then (a) was placed on one surface of (f) as a resin layer, and one side was thermocompressed between rolls set at 250°C, followed by passing it through a heating furnace set at 400°C for 40 seconds to obtain a metal-resin bonded body.

[0073] [Comparative Example 1] Hydrolyzed 3-aminopropyltriethoxysilane was mixed with water and ethanol to a concentration of 0.15 wt%, and then coated with a #9 bar coater onto one surface of (e), which had been cut to A4 size to serve as the metal layer, and the water was dried by heating in an oven at 130°C for 1.5 minutes. (c) was placed on top of the solution-coated metal layer as the resin layer, and one side was thermocompressed between rolls set at 220°C, after which it was passed through a heating furnace set at 320°C for 34 seconds to obtain a metal-resin bonded body.

[0074] Comparative Example 2 Hydrolyzed 3-aminopropyltriethoxysilane was mixed with water and ethanol to a concentration of 0.15 wt%, and then coated with a #9 bar coater onto one surface of (e), which had been cut to A4 size as the metal layer, and the water was dried by heating in an oven at 130°C for 1.5 minutes. (d) was placed on top of the solution-coated metal layer as the resin layer, and an attempt was made to thermocompress it between rolls, one of which was set to 290°C, but the metal and resin layers did not bond, and a metal-resin bonded body could not be obtained.

[0075] Comparative Example 3 In Comparative Example 2, an attempt was made to obtain a metal-resin bonded body in the same manner as in Comparative Example 2, except that the solution containing the hydrolyzate of 3-aminopropyltriethoxysilane was not applied to the surface of (e). However, the metal layer and the resin layer did not bond, and a metal-resin bonded body could not be obtained.

[0076] Comparative Example 4 (f) cut into an A4 size metal layer was annealed in a heating furnace set at 290°C for 18 seconds, and then (c) was placed on one surface of (f) as a resin layer, and one side was thermocompressed between rolls set at 220°C. After that, the metal layer was passed through a heating furnace set at 320°C for 34 seconds to obtain a metal-resin bonded body.

[0077] Comparative Example 5 (g) cut into an A4 size piece to serve as the metal layer was annealed in a heating furnace set at 290°C for 18 seconds, and then (d) was placed on one surface of (g) as the resin layer. An attempt was made to thermocompress the layer between rolls, one of which was set at 290°C, but the metal layer and the resin layer did not bond, and a metal-resin bonded body could not be obtained.

[0078] [Table 1]

[0079] [Table 2]

[0080] In Examples 1 to 5, the resin layer had good adhesion to the metal layer, and high adhesive strength was maintained even after rolling. In a tensile test of the metal-resin bonded body, the metal layer and the resin layer adhered to each other until the test piece broke, and no peeling occurred. Furthermore, the adhesion to polyphenylene sulfide was also good. On the other hand, in all of Comparative Examples 1 to 5, the results showed that the adhesion of the resin layer to the metal layer was poor, and the adhesion to polyphenylene sulfide was also poor. In this example, the peel strength of the metal-resin bonded bodies was evaluated after they were thinly stretched under conditions of a rolling reduction of 50 to 60%. The metal-resin bonded bodies of Examples 1 to 5 exhibited good adhesion even under conditions of a rolling reduction of 50 to 60%, and are suitable for laminate molding applications that include a rolling step, where conformability between the metal layer and the resin layer is particularly required. [Industrial Applicability]

[0081] The metal-resin bonded body of the present invention has excellent processability due to excellent adhesion between the metal layer and the resin layer and good conformability of the resin layer to the metal layer. Therefore, it can be applied to laminate molding processes that involve severe deformation, such as rolling processes. Furthermore, the metal-resin bonded body of this embodiment can exhibit good adhesion to other resin layers (polyphenylene sulfide layers). The metal-resin bonded body of this embodiment is particularly suitable for use in automotive parts (e.g., automotive interior materials, automotive exterior materials, bus bars), and has high industrial value.

Claims

1. A metal layer and a resin layer laminated on the metal layer, The resin layer contains a resin having a polyphenylene sulfide skeleton, the melting peak top temperature of which, as measured by a differential scanning calorimeter (DSC), is in the range of 220 to 270°C.

2. 2. The metal-resin joined body for laminate molding according to claim 1, wherein the 180° peel strength of the resin layer relative to the metal layer is 1.0 N / 20 mm or more when rolled to a rolling reduction of 50 to 60%.

3. 2. The metal-resin bonded body for laminate molding according to claim 1, wherein the resin layer has a thickness of 5 to 200 μm.

4. 2. The metal-resin bonded body for laminate molding according to claim 1, wherein the metal layer comprises aluminum or an aluminum alloy.

5. 2. The metal-resin bonded body for laminate molding according to claim 1, wherein the metal layer comprises copper or a copper alloy.

6. 2. The metal-resin bonded body for laminate molding according to claim 1, wherein the metal layer has a thickness of 0.05 to 2.0 mm.

7. the resin layer has a multilayer structure, 2. The metal-resin bonded body for laminate molding according to claim 1, wherein the resin layer disposed on the metal layer side contains a resin having a polyphenylene sulfide skeleton, the melting peak top temperature of which measured by a differential scanning calorimeter (DSC) is in the range of 220°C to 270°C.

8. The metal-resin bonded article for laminate molding according to claim 1, which is for use in automobile parts.

9. The metal-resin bonded body for laminate molding according to claim 8, which is for use in a bus bar.

10. A laminate obtained by laminating another resin layer on the resin layer of the metal-resin bonded body for laminate molding according to any one of claims 1 to 9.

11. The laminate according to claim 10 , wherein the other resin layer is a polyphenylene sulfide layer.

12. A method for producing a metal-resin bonded body for laminate molding according to any one of claims 1 to 9, A method for producing a metal-resin joined body for laminate molding, comprising a step of joining a metal layer and a resin layer directly or via another layer.

13. 13. The method for producing a metal-resin joined body for laminate molding according to claim 12, comprising: a step 1 of surface-treating a surface of at least one selected from the metal layer and the resin layer with a silane coupling agent treatment liquid; and a step 2 of laminating an untreated resin layer on the surface of the surface-treated metal layer, or laminating an untreated metal layer on the surface-treated resin layer, and bonding them by thermocompression bonding.

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