Integrated molded article and method for manufacturing integrated molded article

Abstract

The present invention addresses the problem of obtaining an integrally molded article of a cylindrical section or a columnar section of a thermosetting resin and a metal member in a lightweight and stable joined state. The present invention for solving the above problem is an integrally molded article in which a metal member (b) and a structural member (a) substantially formed from a fiber-reinforced thermosetting resin are joined, the metal member (b) having an overlap region that overlaps with the structural member (a), at least a portion of the overlap region has a joint portion that is in contact with the structural member (a), and at the joint portion, the ratio ([alpha] tb / [alpha] ta) of the linear expansion coefficient [alpha] tb of the joint circumference of the metal member (b) to the linear expansion coefficient [alpha] ta of the joint circumference of the structural member (a) in a measurement temperature range of 60-150 DEG C ([alpha] tb / [alpha] ta) is 1.0-50.

Description

TECHNICAL FIELD

[0001] The present application relates to an integrated molded product in which a metal member is joined to a structural member formed substantially of a fiber-reinforced thermosetting resin. BACKGROUND

[0002] Fiber-reinforced composite materials are materials that are excellent in mechanical properties and lightweight, and are widely used as parts of aircraft, automobiles, industrial equipment, and the like. In such uses, a frame structure in which a fiber-reinforced composite material is used as a main skeleton is sometimes adopted.

[0003] In this case, it is necessary to form a member that can be connected or detached on a part of a frame material formed of a fiber-reinforced composite material, and such a member has a complicated shape, so it is usually separately manufactured by injection molding, metal processing, or the like, and is fixed to the frame material using an adhesive or a bolt. For example, Patent Literature 1 discloses a method in which a joint portion of a pipe made of a fiber-reinforced resin is bolted and mechanically joined. In addition, Patent Literature 2 discloses a structure in which a pipe made of a carbon fiber-reinforced resin and a metal member are joined using an adhesive. Furthermore, Patent Literature 3 discloses a method in which a carbon fiber-reinforced resin member having a flat surface or a curved surface and a metal member are joined using a hot melt adhesive.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 11-350592

[0007] Patent Literature 2: Japanese Patent Application Laid-Open No. 2016-221784

[0008] Patent Literature 3: Japanese Patent Application Laid-Open No. 2013-244725 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] However, in the method described in Patent Literature 1, there is a concern that the strength of the pipe is reduced due to bolt processing, and there is also a problem of an increase in weight due to the bolt itself. In addition, in the method described in Patent Literature 2, although void-free inside the adhesive and joint strength can be improved, it is necessary to provide a tapered shape, surface irregularities on the adhesive surface, and there is a problem of a reduction in productivity. In addition, in Patent Literature 3, by using a hot melt adhesive composed of a thermoplastic resin, joint strength and productivity can be improved, but it is difficult to expand to a joint technology for a structure in which pressure control can be sufficiently performed, that is, a joint structure of a cylindrical body and a joint.

[0011] The present application aims to obtain an integrated molded product of a metal member and a tubular body of a thermosetting resin in a lightweight and stable joining state.

[0012] Means for solving the problem

[0013] The present application solving the above problem is as follows.

[0014] An integrated molded product of a metal member (b) and a structural member (a) formed substantially of a fiber-reinforced thermosetting resin joined together, the metal member (b) having a lap region that overlaps the structural member (a), at least a portion of the lap region having a joining portion that interfaces with the structural member (a), and at the joining portion, the linear expansion coefficient α tb of the metal member (b) in a measurement temperature range of 60°C to 150°C is 1.0 to 50 times the linear expansion coefficient α ta of the joining portion of the structural member (a). tb ta

[0015] Effects of the invention

[0016] According to the present application, an integrated molded product of a metal member and a structural member formed substantially of a fiber-reinforced thermosetting resin can be obtained in a lightweight and stable joining state. BRIEF DESCRIPTION OF DRAWINGS

[0017] [ Figure 1 ] is a schematic view showing an example of a joint as the metal member (b).

[0018] [ Figure 2 ] is a schematic view showing an example of an integrated molded product of the joint shown in Figure 1 and the structural member (a) joined together.

[0019] [ Figure 3 ] is a schematic view showing an example of a base as the metal member (b).

[0020] [ Figure 4 ] is a schematic view showing an example of an integrated molded product of the base shown in Figure 3 and the structural member (a) joined together.

[0021] [ Figure 5 ] is a schematic view showing an example of a second tubular body as the metal member (b).

[0022] [ Figure 6 ] is a schematic view showing an example of an integrated molded product of the second tubular body shown in Figure 5 and the structural member (a) joined together. ​​

[0023] [ Figure 7 ]is a cross-sectional view showing an example of a joint of the structural member (a) and the metal member (b). DETAILED DESCRIPTION

[0024] Hereinafter, a preferred embodiment of the present application will be described.

[0025] The integrated molded product according to the present application is an integrated molded product in which a metal member (b) and a structural member (a) formed substantially of a fiber-reinforced thermosetting resin are joined. Note that, in the present application, the term "substantially formed of a certain material" means that the material is included as a main component, and typically the material alone is included, but other components can also be included as long as the effect of the present application is not impaired. Specifically, as described later, the structural member (a) can have a thermoplastic resin region on the surface, but as long as the majority of the region of the structural member (a) that ensures the strength of the member is formed of a fiber-reinforced thermosetting resin, the structural member (a) is described as being substantially formed of a fiber-reinforced thermosetting resin. The structural member (a) is preferably formed of a fiber-reinforced thermosetting resin for 90% or more of the volume, for example.

[0026] The fiber included in the fiber-reinforced thermosetting resin of the structural member (a) according to the present application can use a substance that is generally used as a reinforcing fiber. For example, glass fiber, polyacrylonitrile-based carbon fiber, rayon-based carbon fiber, lignin-based carbon fiber, pitch-based carbon fiber (including graphite fiber), potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, gypsum fiber, and metal fiber can be mentioned, and among these, glass fiber, polyacrylonitrile-based carbon fiber, and pitch-based carbon fiber are preferable, and from the viewpoint of lightness and mechanical properties, polyacrylonitrile-based carbon fiber and pitch-based carbon fiber are more preferable, and polyacrylonitrile-based carbon fiber is particularly preferable.

[0027] From the viewpoint of improving the mechanical properties, the fiber contained in the structural member (a) is preferably surface-treated with a sizing agent. As the sizing agent, mention can be made of multifunctional epoxy resins, acrylic polymers, polyols, polyethyleneimines, and the like, and specifically, mention can be made of glycerol triglycidyl ether, dipropylene glycol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, arabitol polyglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol polyglycidyl ether, and the like of aliphatic polyols, polyacrylic acid, copolymers of acrylic acid and methacrylic acid, copolymers of acrylic acid and maleic acid, or a mixture of two or more of them, polyvinyl alcohol, glycerol, dipropylene glycol, polyglycerol, sorbitol, arabitol, trimethylolpropane, pentaerythritol, polyethyleneimines containing a large number of amino groups in one molecule, and the like. Among these, from the viewpoint of containing a large number of highly reactive epoxy groups in one molecule, and being highly water-soluble and easy to coat onto the fiber, glycerol triglycidyl ether, dipropylene glycol polyglycidyl ether, and polyglycerol polyglycidyl ether can be preferably used in the present application. The sizing agent is preferably contained in an amount of 0.01 to 5 parts by mass, and more preferably in an amount of 0.1 to 2 parts by mass, relative to 100 parts by mass of the fiber.

[0028] The fiber contained in the structural member (a) is preferably a continuous fiber. Here, the so-called continuous fiber in the present specification means a fiber having a length of 10 mm or more, and does not necessarily need to be a fiber continuous in the entire member, but can be cut in the middle. As the form of the continuous fiber, mention can be made of the form of a woven fabric in which a fiber bundle is woven, the form in which filaments, braids, filament bundles, spun yarns, and the like are aligned in one direction. Alternatively, two or more of these forms of reinforcing fibers can be used in combination to form the structural member (a).

[0029] The structural member (a) is preferably a molded body having a laminated structure obtained by laminating and molding prepreg sheets formed of a fiber-reinforced thermosetting resin. In the case where the prepreg sheet is in the form in which reinforcing fibers are aligned in one direction, it is preferable to use a laminate in which the angle of the reinforcing fibers is approximately 0°, approximately ±45°, approximately 90°, and the like, and a layer having an angle other than the above can be included.

[0030] The mass content of the fiber present in 100 mass% of the structural member (a) is preferably 20 to 70 mass%, more preferably 25 to 70 mass%, and particularly preferably 30 to 65 mass%. By setting the mass content of the fiber within the above range, a structural member (a) having high rigidity and good dimensional accuracy can be obtained.

[0031] The type of thermosetting resin constituting the fiber-reinforced thermosetting resin of the structural member (a) is not particularly limited, and examples thereof include unsaturated polyester resins, vinyl ester resins, epoxy resins, phenol-formaldehyde (Resol type) resins, urea-triamine resins, polyimide resins, copolymers, modified bodies, and resins obtained by blending at least two of these. Among these, a thermosetting resin in which an epoxy resin is the main component is more preferable from the viewpoint of the mechanical properties of the molded product, because it has excellent rigidity and strength. Note that the main component in the thermosetting resin refers to a component having a content ratio of 60% by mass or more.

[0032] In addition, the fiber-reinforced thermosetting resin can contain other fillers and additives according to the use and the like. Examples thereof include elastomer or rubber components, inorganic fillers, flame retardants, electrically conductive agents, antibacterial agents, insect repellents, odor repellents, coloration preventing agents, release agents, antistatic agents, plasticizers, colorants, pigments, dyes, foaming agents, blowing agents, coupling agents, and the like.

[0033] In the present application, the structural member (a) can have a cylindrical portion or a columnar portion in at least a part thereof. Here, the columnar shape refers to a solid shape in which no hollow is present in the cylindrical portion. Typically, the structural member (a) can have a shape in which a columnar shape or a cylindrical shape is formed as a whole. Alternatively, the structural member (a) can have a shape in which a cylindrical portion or a columnar portion and a shape other than this are present together. Furthermore, in the case where a cylindrical portion is present, it can have a shape in which the wall thickness of the cylindrical portion is uneven. The cylindrical portion or the columnar portion of the structural member (a) can be curved.

[0034] In the case where the structural member (a) has a cylindrical portion, it is preferable to have a pipe shape in which the length in the direction perpendicular to the opening surface with respect to the diameter of the cylindrical shape is longer, from the viewpoint of lightweight and high rigidity. In the case where the structural member (a) is a cylindrical body in which a cylindrical shape is formed as a whole, it is particularly preferable to be a member in which a pipe shape is formed as a whole, that is, a pipe material, because it is easy to apply the integrated molded product to a frame structure and the like.

[0035] The shape of the radial cross section of the cylindrical portion or the columnar portion of the structural member (a) is not particularly limited, and it is preferable to be circular or rectangular. In addition, the cross-sectional area of the cylindrical portion or the columnar portion of the structural member (a) is preferably 20 mm 2 More preferably, it is 50 mm 2 or less. In addition, it is preferably 300 mm 2 More preferably, it is 200 mm 2 or less. In the case where the radial cross-sectional area of the structural member (a) is within this range, it is possible to obtain an integrated molded product having high rigidity with good productivity.

[0036] The structural member (a) is formed substantially of a thermosetting resin, and particularly in the portion to be joined to the metal member (b), if there is a thermoplastic resin region exposed on the surface thereof, it is possible to easily form a state in which the structural member (a) and the metal member (b) are joined by heat fusion, particularly a state in which, as described later, a thermoplastic resin exists on the surface of the structural member (a) on the side of the structural member (a) farther from the joining boundary surface, by heat fusion of the metal member (b) via the thermoplastic resin region. Such a thermoplastic resin region is typically provided thinly on the surface of the structural member (a), and the thickness thereof is usually 1 to 300 μm, and more preferably 50 to 150 μm.

[0037] As for the form of such a thermoplastic resin region, there is no particular limitation as long as a region in which a thermoplastic resin is exposed is formed on the surface of the structural member (a), and for example, a layered form, a dot form, a mesh form, a lattice form, and the like can be exemplified.

[0038] Further, as the thermoplastic resin constituting such a thermoplastic resin region, a polyolefin resin, a polyester resin, a polyamide resin, a polycarbonate resin, a polyphenylene sulfide resin, a polyimide resin, a polyamide-imide resin, a polyether-imide resin, a polyether ketone resin, a polyether ether ketone resin, a polyether ketone ketone resin, a polyarylate resin, and the like are preferable.

[0039] In the case where a thermoplastic resin region exists in the structural member (a), from the viewpoint of obtaining a high joining strength, it is preferable that the interface between the thermosetting resin of the structural member (a) and the thermoplastic resin region be formed in a concave-convex shape. Here, by the interface being formed in a concave-convex shape, it is meant that the boundary surface between the thermosetting resin and the thermoplastic resin region is not flat, but is formed as a boundary surface in which a form in which the thermosetting resin side is concave and a form in which the thermoplastic resin region side is concave exist in mixture. The depth of the concave at this time is preferably 1 to 200 μm, and more preferably 10 to 100 μm.

[0040] In the present application, the method for producing the structural member (a) is not particularly limited. In the case where the structural member (a) is a cylindrical body, as the production method, a method in which a prepreg or the like in which a reinforcing fiber impregnated with a thermosetting resin is laid in a filament is wound around a mandrel while applying a prescribed tension thereto and is shaped and then cured, a method in which an inner pressure molding or press molding using a shaping mold is performed and then cured, and the like can be exemplified. As the method for forming the thermoplastic resin region on at least a portion of the outer peripheral surface or the inner peripheral surface of the structural member (a), a method in which at least one layer of a film formed of a thermoplastic resin is wound at the beginning or the end in the above-described method and is cured integrally with the thermosetting resin can be exemplified.

[0041] The metal member (b) in the present application is a member consisting essentially of a metal. The metal is not particularly limited, and examples thereof include aluminum, copper, nickel, tin, gold, silver, iron, magnesium, chromium, tungsten, zinc, lead, and the like, and alloys thereof. In addition, the metal member (b) can be composed of one metal, or two or more metals can be combined. Among them, an aluminum alloy, a titanium alloy, and most preferably an aluminum alloy are preferred because of their high specific strength.

[0042] The metal member (b) is preferably any of a joint or a base. Typically, the joint is a member for connecting two cylindrical portions or columnar portions, or changing the direction, or linking cylindrical portions or columnar portions having different diameters to each other, or converging or branching three or more cylindrical portions or columnar portions. The base is a member for receiving and placing a cylindrical portion or a columnar portion. In the present application, at least one of these cylindrical portions is the aforementioned structural member (a) having a cylindrical portion, and in a preferred embodiment, they are all the aforementioned cylindrical portions. Figure 1 A to D of FIG. 1 show schematic diagrams of representative joints, Figure 2 A to D of FIG. 2 show schematic diagrams of integrated molded products in which the structural member (a) (cylindrical body) and the joint are integrated, Figure 3 A to B of FIG. 3 show schematic diagrams of representative bases, Figure 4 A to B of FIG. 4 show schematic diagrams of integrated molded products in which the structural member (a) (cylindrical body) and the base are integrated, but the respective structures are not limited thereto.

[0043] In addition, the metal member (b) can be a cylindrical body. Typically, the so-called cylindrical body refers to a cylindrical body having a length, a diameter, a thickness, or the like that is different from that of the cylindrical portion or the columnar portion of the structural member (a). Figure 5 A to B of FIG. 5 show schematic diagrams of representative cylindrical bodies, Figure 6 A to B of FIG. 6 show schematic diagrams of integrated molded products in which the structural member (a) (first cylindrical body) 1 and the metal member (b) (second cylindrical body) 2 are integrated, but the respective structures are not limited thereto.

[0044] At least a part of the surface of the metal member (b) can be subjected to surface treatment. As the surface treatment method, roughening treatment, easy-adhesion treatment, antistatic treatment, sandblasting treatment (sand surface treatment), corona discharge treatment, plasma treatment, excimer treatment, chemical etching treatment, water mat treatment, flame treatment, acid treatment, alkali treatment, oxidation treatment, ultraviolet irradiation treatment, silane coupling agent treatment, and the like can be mentioned.

[0045] In the present application, the metal member (b) can also have a thermoplastic resin region on at least a part of its surface. Thereby, the structural member (a) and the metal member (b) can be joined by heat fusion via the thermoplastic resin region. In a more preferable mode, both the structural member (a) and the metal member (b) have such a thermoplastic resin region, and the thermoplastic resin region of the structural member (a) and the thermoplastic resin region of the metal member (b) are joined by heat fusion. In the case where both the structural member (a) and the metal member (b) have a thermoplastic resin region, the kind of the thermoplastic resin constituting the thermoplastic resin region in both the structural member (a) and the metal member (b) is preferably the same from the viewpoint of the joining strength of both.

[0046] Such a thermoplastic resin region is typically thin and is provided by, for example, coating a thermoplastic resin on the surface of the metal member (b), and the thickness thereof is usually 10 to 300 μm, and more preferably 50 to 150 μm. The form of the thermoplastic resin region can be exemplified by, for example, a layer shape, a dot shape, a mesh shape, a lattice shape, and the like.

[0047] In addition, in the case where both the structural member (a) and the metal member (b) have a thermoplastic resin region on the surface, the kind of the thermoplastic resin constituting the thermoplastic resin region of both is preferably the same from the viewpoint of the joining strength of the structural member (a) and the metal member (b).

[0048] In the integrated molded product of the present application, the metal member (b) has a lap region where the structural member (a) is overlapped, and in at least a part of the lap region, a joining portion where the structural member (a) is joined is present. By the term "the metal member (b) is overlapped with the structural member (a)", it means that at least a part of the structural member (a) and the metal member (b) are in surface contact. Also, by the term "lap region", it means the region where the contact is made.

[0049] Figure 7 A and B are modes in which the metal member (b), i.e., the joint 2, is joined to the outer peripheral surface of the structural member (a) 1, and in these modes, the inner peripheral surface of the tubular metal member (b) is in contact with the outer peripheral surface of the structural member (a) via the thermoplastic resin layer 3 in a manner that the outer peripheral surface of the structural member (a) is surrounded on the entire circumference. That is, the metal member (b) is overlapped with the structural member (a) on the entire circumference. The metal member (b) can be in contact with the outer peripheral surface or the inner peripheral surface of the structural member (a) not on the entire circumference but only on a part thereof, but in order to exhibit a strong joining strength, the lap region is preferably formed by joining the metal member (b) in a range of 50% or more of the circumference of the tubular portion or the columnar portion of the structural member (a) mentioned above, and particularly preferably in a range of 100% (the entire circumference), i.e., the lap region forms a closed cross section. Particularly, Figure 7The embodiment of the B of the structure member (a) shown in FIG. 1 is more preferable, in which the thermoplastic resin exists on the surface of the structure member (a) on the structure member (a) side than on the joining boundary surface.

[0050] Note that, in the case of joining with the cylindrical portion of the structure member (a), which one of the outer peripheral surface and the inner peripheral surface to lap to join the metal member (b) is a matter to be determined depending on the target member, and from the viewpoint of productivity, it is preferable to lap the outer peripheral surface of the cylindrical portion of the structure member (a) to join. In addition, the integrally molded product can have both the metal member (b) joined by lapping the outer peripheral surface and the metal member (b) joined by lapping the inner peripheral surface.

[0051] In the present application, by designing the gap between the structure member (a) and the metal member (b) in the range of -0.1 to 0.1 mm, the pressure caused by the difference in expansion rate can be sufficiently imparted, and in addition, breakage of the structure member (a) or the metal member (b) due to the imparted excessive pressure can be prevented. The gap between the structure member (a) and the metal member (b) is preferably -0.075 to 0.075 mm, and more preferably -0.05 to 0.05 mm. The gap between the structure member (a) and the metal member (b) means the shortest distance from the outer peripheral surface of the member on the inner peripheral side to the inner peripheral surface of the member on the outer peripheral side in the lapped region. For example, in the case where the cross-sectional shape of the structure member (a) and the metal member (b) is elliptical and the metal member (b) is on the inner peripheral side of the structure member (a), the shortest distance from the outer peripheral surface of the metal member (b) to the structure member (a) at 0 / 90 / 180 / 270° is measured as the gap.

[0052] From the viewpoint of stress concentration, in any radial cross section of the cylindrical portion or the columnar portion of the structure member (a) in the lapped region, the coefficient of variation of the gap between the structure member (a) and the metal member (b) is preferably 2.0% or less, and more preferably 0.5% or less.

[0053] In addition, the metal member (b) is substantially composed of metal, and the shape change of each member due to heat input at the time of joining is extremely small, and thus an integrally molded product with high dimensional accuracy can be obtained. In the case of joining with the cylindrical portion of the structure member (a), that is, in the case of having a lapped region in contact with the cylindrical portion, the concentricity indicating the shift of the cross-sectional center of the structure member (a) and the metal member (b) in the lapped region is preferably 0.25 mm or less. The concentricity can be measured by comparing the geometric center positions of the structure member (a) and the metal member (b) using a CNC three-coordinate measuring machine.

[0054] In the present application, at the joining portion, by the linear expansion coefficient α of the joining circumference of the aforementioned metal member (b) in the measurement temperature range of 60°C to 150°Ctb linear expansion coefficient of the joint circumference of the structural member (a) ta ratio (a tb / a ta ) is in the range of 1.0 to 50, so that a sufficient pressure can be imparted without generating voids by the difference in expansion rate, and the flow of the thermoplastic resin layer to the outside due to the imparted excessive pressure can be suppressed. a tb / a ta is preferably 1.5 to 20, and more preferably 2.0 to 10. Note that the so-called joint circumference in the present specification refers to a curve along a joint surface in a cross section of the integrated molded article perpendicular to the joint portion, and the linear expansion coefficient of the joint circumference of the member refers to the easiness of expansion of the joint circumference of the member due to heating. The linear expansion coefficient of the joint circumference of the member can be calculated by raising the temperature of the member from 30°C at a temperature increase rate of 5°C / min to 180°C, and dividing the expansion amount of the length of the joint circumference during 60°C to 150°C by the length of the joint circumference at 60°C and the temperature change amount. For example, in the case where the structural member (a) is a structural member having a cylindrical portion or a columnar portion, the metal member (b) has a lapping region lapping the outer circumferential surface and / or the inner circumferential surface of the cylindrical portion or the columnar portion of the structural member (a), and has a joint portion at the lapping region with the structural member (a), the joint circumference of the structural member (a) refers to the outer circumference and / or the inner circumference of the cylindrical portion or the columnar portion in any cross section of the integrated molded article. For example, in the case where the structural member (a) is located on the inner circumferential side of the metal member (b) in an elliptical pipe, the linear expansion coefficient of the joint circumference of the member can be calculated by measuring the expansion amount of the outer circumference in any cross section of the structural member (a). As for the expansion amount of the member, the member is placed on a hot plate, and the length of the joint circumference before and after heating is measured from an image captured using a camera or a microscope, and the change amount is calculated, whereby the expansion amount can be measured.

[0055] In addition, if the ratio (a tc linear expansion coefficient of the joint circumference of the structural member (a) ta ratio (a tc / a ta ) is in the range of 1.5 to 10, the generation of voids in the thermoplastic resin layer at the time of integrated molding can be suppressed, and a high joint strength can be obtained. It is preferably in the range of 1.5 to 7.5, and more preferably in the range of 2.0 to 5.0.

[0056] From the viewpoint of obtaining a high joint strength, the linear expansion coefficient a tcPreferably, it is 60 ppm / °C or more, more preferably 70 ppm / °C or more, and in addition, it is preferably 200 ppm / °C or less, more preferably 150 ppm / °C or less.

[0057] At the joint of the structural member (a) and the metal member (b), a thermoplastic resin layer is preferably present on the surface of the structural member (a) on the side of the structural member (a) as compared to the joint boundary surface. Here, the state in which a thermoplastic resin layer is present on the surface of the structural member (a) on the side of the structural member (a) as compared to the joint boundary surface means a state in which, in a cross section of the joint, a line that becomes the outer periphery of the structural member (a) is taken as the joint boundary surface, and a thermoplastic resin layer is present on the side of the structural member (a) as compared to the joint boundary surface.

[0058] At the joint of the structural member (a) and the metal member (b), a part of the fiber contained in the structural member (a) is preferably in a state of straddling the thermosetting resin and the thermoplastic resin layer that constitute the structural member (a), that is, in contact with both the thermosetting resin and the thermoplastic resin layer of the structural member (a). By forming such a structure, it is possible to form a firm joint state using the fiber reinforcement effect. This effect is particularly significant in the case where the fiber contained in the structural member (a) is a continuous fiber.

[0059] The joint strength of the structural member (a) and the metal member (b) is preferably 7 MPa or more, more preferably 10 MPa or more. There is no particular limitation on the upper limit of the joint strength, and from the viewpoint of obtaining the integrated molded product of the present application with good productivity, it is preferably 100 MPa or less.

[0060] As an example, the integrated molded product of the present application can be manufactured by the following method: preparing a structural member (a) having a thermoplastic resin region on at least a part of the outer peripheral surface and / or the inner peripheral surface of the cylindrical portion or the columnar portion, and a metal member (b) optionally having a thermoplastic resin region on at least a part of the surface, and contacting the structural member (a) and the metal member (b) in a manner of overlapping the region including the heated thermoplastic resin region, in a state where the structural member (a) and / or the metal member (b) is heated. The method of such heat fusion is not particularly limited, and hot plate fusion, vibration fusion, ultrasonic fusion, far infrared ray heating fusion, dielectric heating fusion, laser fusion, etc. can be used. At this time, it is preferable to heat to a temperature at which the thermoplastic resin of the thermoplastic resin region constituting the structural member (a) or the metal member (b) softens, and more preferably to a temperature at which it melts.

[0061] The integrated molded article of the present application is lightweight and has high rigidity, and therefore is suitable for use as a component of a frame structure. As such a structure, the body and arm of an industrial robot, a car, a motorcycle, a bicycle, an aircraft, a helicopter, an unmanned aerial vehicle, a ship, a submarine, and the like can be given. In particular, from the viewpoint of rigidity and lightness, the integrated molded article of the present application is preferably used as a structural component for an aircraft, a helicopter, an unmanned aerial vehicle, or the like.

[0062] In addition, since the arm component including the integrated molded article of the present application is lightweight, it is suitable for use in a multicopter-type aircraft having three or more rotors. From the viewpoint that the effect of weight reduction is enhanced, a multicopter-type aircraft having six or more, more preferably eight or more, rotors is preferred.

[0063] The weight of the arm component including the integrated molded article of the present application is preferably in the range of 300 g or less. There is no particular limitation on the lower limit of the weight, and from the viewpoint of the operation of the aircraft, 50 g or more is preferred. In addition, from the viewpoint of determining the center of gravity of the aircraft, the coefficient of variation of the weight of the arm component including the integrated molded article of the present application is preferably in the range of 0.1 to 1.0%.

[0064] The integrated molded article of the present application is lightweight, and therefore an aircraft using the integrated molded article of the present application can carry articles, and the load weight can account for 20 to 60% of the total weight of the aircraft.

[0065] Example

[0066] The following examples further specifically illustrate the present application, but the present application is not limited in any way by the examples.

[0067] (Example 1)

[0068] A polyamide film was obtained by hot-pressing pellets of a copolymer polyamide resin (Toray CM4000, polyamide 6 / 66 / 610, melting point 150°C). A polyamide film of the aforementioned polyamide film having a thickness of 70 μm was wound once on a release-treated stainless steel mandrel having an outer diameter of 30 mm, a taper of 6.0 / 1000, and a length of 700 mm, as a thermoplastic resin layer, and then "Torayca prepreg" P3051S-30 and P3052S-12 manufactured by Toray (Co., Ltd. ) were layered in such a manner that P3051S-30 became a material angle of 0 degrees and P3052S-12 became a material angle of 60 degrees when the long side direction of the mandrel was set as the 0-degree axis. Further, a wrapping tape (heat-resistant film tape, width 10 mm) was wound at a tension of 3 kg on the outside thereof, and heat molding was performed in a curing oven at 150°C for 30 minutes. Then, the mandrel was extracted, the wrapping tape was removed, and then cut, to obtain a pipe 1 having a thickness of 0.5 mm and a length of 500 mm.

[0069] Cross-sectional observation of the pipe 1 was performed using a digital microscope (manufactured by Keyence (Co., Ltd. ), VHX-5000), and as a result, it was confirmed that reinforcing fibers were present across the boundary surface between the thermoplastic layer and the thermoset layer. The pipe 1 was heated to 150°C, and as a result, the inner diameter expanded by 36 μm, and the calculated linear expansion coefficient α ta of the joint circumference was 9.6 ppm / °C. In addition, likewise, the linear expansion coefficient of the joint circumference of the thermoplastic resin layer was 71 ppm / °C.

[0070] Next, an annular A2000-series aluminum molded body having an outer diameter of 28 mm and a length of 30 mm was prepared. The aluminum molded body was heated to 150°C, and as a result, the outer diameter expanded by 59 μm, and the calculated linear expansion coefficient α tb of the joint circumference was 23.4 ppm / °C.

[0071] That is, in the present embodiment, α tb / α ta = 2.44.

[0072] Then, the pipe was fitted to the aluminum molded body in a state in which the inner circumferential surface of the pipe 30 mm from the end portion was in contact with the outer circumferential surface of the aluminum molded body, and fixed using a vise, and the aluminum molded body was heated to 200°C using a far infrared heater, and cooled, whereby an integrated molded product was manufactured.

[0073] With respect to the obtained integrated molded product, the joint portion was observed using a digital microscope (manufactured by Keyence (Co., Ltd. ), VHX-5000), and the thickness of the thermoplastic resin layer was measured at four arbitrary points, and as a result, the average value was 69.3 μm, and the coefficient of variation was 0.2%.

[0074] With respect to the integrated molded product obtained for N = 5, the pipe 1 and the aluminum molded body were fixed with a dedicated jig, and a tensile test was performed. As a result, all of the 5 showed a bonding strength of 15 MPa or more.

[0075] (Example 2)

[0076] A mandrel of SS400 material with an outer diameter of 28 mm and a length of 1.5 m was subjected to a release treatment. On the mandrel subjected to the release treatment, "Torayca prepreg" P3051S-30 manufactured by Toray Industries, Inc. was stacked in a manner in which the long edge direction of the mandrel was set as the 0° axis to be ±45°, 90°, and 0°, and a polyamide film identical to that of Example 1 was adjusted to 100 μm and wound once as a thermoplastic resin layer. Further, a wrapping tape (heat-resistant film tape, width 10 mm) was wound at a tension of 3 kg on the outside thereof, and heat molding was performed in a curing oven at 150°C for 30 minutes. Then, the mandrel was extracted, the wrapping tape was removed, and then cut, to obtain a pipe 2 with a thickness of 0.5 mm and a length of 500 mm. The pipe 2 was subjected to cross-sectional observation with a digital microscope (manufactured by Keyence Corporation, VHX-5000), and as a result, it was confirmed that reinforcing fibers were present across the boundary surface between the thermoplastic layer and the thermoset layer.

[0077] The pipe 2 was heated to 150°C, and as a result, the outer diameter expanded by 36 μm, and the calculated linear expansion coefficient α ta of the bonding circumference was 10.2 x ppm / °C. In addition, likewise, the linear expansion coefficient of the bonding circumference of the thermoplastic resin layer was 84 ppm / °C.

[0078] Next, a ring-shaped aluminum molded body of A2000 series with an inner diameter of 28.3 mm, an outer diameter of 40 mm, and a length of 30 mm was prepared. The aluminum molded body was heated to 150°C, and as a result, the inner diameter expanded by 59 μm, and the calculated linear expansion coefficient α tb of the bonding circumference was 22.5 ppm / °C.

[0079] That is, in the present example, α tb / α ta = 2.21.

[0080] Then, the aluminum molded body was fitted to the pipe in a state in which the pipe was heated to 150°C, in a state in which the inner circumferential surface of the pipe from the end portion by 30 mm was in contact with the outer circumferential surface of the aluminum molded body, and was fixed with a vice, and cooling was performed, to thereby manufacture an integrated molded product.

[0081] The thickness of the thermoplastic resin layer was measured in the same manner as in Example 1, and as a result, the average value was 98.7 μm, and the coefficient of variation of the bonding circumference was 0.4%.

[0082] The same tensile test as in Example 1 was performed, and the results of the five showed a bonding strength of 17 MPa or more.

[0083] (Example 3)

[0084] The same experimental procedure as in Example 2 was performed, except that a polyamide film having a thickness of 300 μm was used. The thickness of the thermoplastic resin layer was measured using the same procedure as in Example 1, and the average value was 298.7 μm with a coefficient of variation of 1.5%.

[0085] The same tensile test as in Example 1 was performed, and the results of the five showed a bonding strength of 9 MPa or more.

[0086] (Example 4)

[0087] A female mold having a concave shape was prepared, and after a polyamide film adjusted to 100 μm was disposed, 10 sheets of "Torayca prepreg" P3051S-12 manufactured by Toray Industries, Inc. were laminated in the female mold in such a manner that the formed product, when the long side direction thereof is set to 0°, becomes [0° / 90°]5s, to give a shape thereto. Then, a male mold was set, and press molding was performed while applying a pressure of 5 MPa for 30 minutes at 150°C, to produce a member 1. The member 1 was formed into a cross-sectional shape in the form of a U letter corresponding to the concave shape of the female mold, and had a thickness of 1.2 mm and each side of 10 cm.

[0088] The member 1 was subjected to cross-sectional observation using a digital microscope (manufactured by Keyence Corporation, VHX-5000), and as a result, it was confirmed that reinforcing fibers were present across the boundary surface between the thermoplastic layer and the thermoset layer. The member 1 was heated to 150°C, and as a result, the three sides collectively expanded by 202 μm, and the calculated linear expansion coefficient α ta of the bonding periphery was 7.5 ppm / °C. In addition, likewise, the linear expansion coefficient of the bonding periphery of the thermoplastic resin layer was 86 ppm / °C.

[0089] Next, an A2000 series aluminum formed product having each side of 10 cm and a thickness of 10 mm in the form of a U letter was prepared. The aluminum formed product was heated to 150°C, and as a result, the three sides collectively expanded by 653 μm, and the calculated linear expansion coefficient α tb of the bonding periphery was 24.2 ppm / °C.

[0090] That is, in the present example, α tb / α ta = 3.23.

[0091] The aluminum formed product was fixed in a state where the outer peripheral surface of the member 1 and the inner peripheral surface of the aluminum formed product were in contact, in a state where the aluminum formed product was heated to 300°C using a far infrared heater, and cooling was performed, to thereby produce an integrated formed product.

[0092] With respect to the one-piece formed product obtained for N = 5, a drop test was performed in which the joint portion was dropped from a height of 1.5 m with the joint portion facing downward, and the joint state at that time was confirmed visually. As a result, no change was observed in the joint portion in 5, and a good joint state was maintained.

[0093] (Comparative Example 1)

[0094] The same operation as in Example 2 was performed, except that a ring-shaped tungsten formed product having an inner diameter of 28.4 mm, an outer diameter of 40 mm, and a length of 30 mm was prepared instead of the aluminum formed product. The tungsten formed product was heated to 150°C, and as a result, the inner diameter expanded by 14.6 μm, and the calculated linear expansion coefficient was 4.1 ppm / °C.

[0095] That is, in the present comparative example, α tb / α ta = 0.40.

[0096] The one-piece formed product was pulled by hand, and as a result, the pipe 2 and the tungsten formed product easily separated, and did not have sufficient joint strength.

[0097] Explanation of Reference Numerals

[0098] 1 structural member (a) (first cylindrical body)

[0099] 2 metal member (b) (joint, base, or second cylindrical body)

[0100] 3 thermoplastic resin

Claims

1. An integrated molded product which is an integrated molded product of a metal member (b) and a structural member (a) formed substantially of a fiber-reinforced thermosetting resin, the metal member (b) having a lap region which overlaps the structural member (a), at least a part of the lap region having a joint portion which interfaces with the structural member (a), and at the joint portion, a ratio (α tb / α ta ) of a linear expansion coefficient α tb of the joint circumference of the metal member (b) in a measurement temperature range of 60°C to 150°C to a linear expansion coefficient α ta of the joint circumference of the structural member (a) is 1.0 to 50.

2. The integrally formed article of claim 1, wherein, The structural member (a) is a structural member having a cylindrical portion or a columnar portion, The metal member (b) has a lapped region lapping the outer peripheral surface and / or the inner peripheral surface of the cylindrical portion or the columnar portion of the structural member (a), and has a joint portion at least a part of the lapped region being joined to the structural member (a).

3. The integrally formed article of claim 1 or 2, wherein, The structural member (a) has an exposed thermoplastic resin region on the surface, The metal member (b) has a lapped region lapping the structural member (a), and has a joint portion at least a part of the lapped region being joined to the structural member (a) via a thermoplastic resin layer.

4. The integrally formed article of claim 3, wherein, At the joint portion, the linear expansion coefficient α of the joint periphery of the thermoplastic resin layer tc the linear expansion coefficient α of the joint periphery of the structural member (a) ta is 1.5 to 10. tc / α ta ).

5. The integrally formed article of claim 3, wherein, The linear expansion coefficient α of the periphery of the thermoplastic resin layer tc is 60 ppm / °C or more and 200 ppm / °C or less.

6. The integrally formed article of claim 3, wherein, The thickness of the thermoplastic resin layer is 10 to 300 μm.

7. The integrally formed article of claim 2, wherein, In any radial cross section of the cylindrical portion or the columnar portion of the structural member (a) in the lapped region, the gap between the structural member (a) and the metal member (b) is -0.1 to 0.1 mm.

8. The integrally formed article of claim 7, wherein, The coefficient of variation Cv of the gap is 2.0% or less.

9. The integrally molded product according to claim 2, which is an integrally molded product in which a metal member (b) is joined to a structural member (a) formed substantially of a fiber-reinforced thermosetting resin and having a cylindrical portion or a columnar portion, The structural member (a) has an exposed thermoplastic resin region on the surface of the outer peripheral surface and / or the inner peripheral surface of the cylindrical portion or the columnar portion, The metal member (b) has a lapped region lapping the outer peripheral surface and / or the inner peripheral surface of the cylindrical portion or the columnar portion of the structural member (a), and has a joint portion at least a part of the lapped region being joined to the structural member (a) via a thermoplastic resin layer, and At the joint portion, the linear expansion coefficient α of the joint circumference of the metal member (b) in a measured temperature range of 60°C to 150°C tb is 1.0 to 50 times the linear expansion coefficient α of the joint circumference of the structural member (a) ta . tb / α ta ).

10. The integrally formed article of claim 2 or 9, wherein, The fiber included in the structural member (a) is a continuous fiber, and the continuous fiber is in contact with both the thermosetting resin constituting the structural member (a) and the thermoplastic resin layer.

11. The integrally formed article of claim 1 or 2, wherein, The joint strength of the structural member (a) and the metal member (b) is 7 MPa or more and 100 MPa or less.

12. The integrally formed article of claim 2 or 9, wherein, The metal member (b) has a cylindrical portion in which the lapped region is present, and in the lapped region, the concentricity of the cylindrical portion or the columnar portion of the structural member (a) and the cylindrical portion of the metal member (b) is 0.25 mm or less.

13. The integrally formed article of claim 2 or 9, wherein, The structural member (a) is a member integrally formed in a tubular shape.

14. The integrally formed article of claim 2 or 9, wherein, The metal member (b) is a joint or a pedestal.

15. A frame structure comprising the integrally molded product according to claim 2 or 9.

16. An aircraft which is made using the integrally molded product according to claim 1, 2 or 9.

17. An aircraft which is a multi-rotor aircraft carrying three or more arm members each of which comprises the integrally molded product according to claim 2 or 9.

18. The aircraft of claim 17, wherein, The weight of the arm member is 50 to 300 g.

19. The aircraft of claim 17, wherein, The coefficient of variation Cv of the weight of the arm member is 0.1 to 1.0%.

20. The aircraft according to any one of claims 16 or 17, which is a cargo-carrying aircraft, and the carrying weight is 20 to 60% of the total weight of the aircraft.

21. A method for producing an integrated molded article, which is an integrated molded article produced by joining a structural member (a) formed substantially of a fiber-reinforced thermosetting resin and a metal member (b) via heat fusion of a thermoplastic resin layer, In the method for producing an integrated molded article, a structural member (a) having a thermoplastic resin region in at least a part of a surface layer and a metal member (b) optionally having a thermoplastic resin region in at least a part of a surface are prepared, and the structural member (a) and the metal member (b) are contacted in a state in which the structural member (a) and / or the metal member (b) is heated, in a manner in which they are overlapped in a region including the thermoplastic resin region of the structural member (a).

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