Method for manufacturing composite member, and composite member

Abstract

To provide a method for manufacturing composite members with excellent bonding strength and airtightness.SOLUTION: According to an aspect of the present invention, there is provided a method for manufacturing a composite member consisting of an aluminum member and a resin member joined together. The manufacturing method includes the following processes. In a blasting process, the surface of the aluminum member is blasted to form irregularities on the surface of the aluminum member. In a surface hydroxylation process, the surface of the aluminum member with the uneven surface is hydrothermally treated to modify the uneven surface into aluminum hydroxide and to form surface nanostructure on the uneven surface. In a film formation process, a bonding agent containing a triazine thiol derivative is supplied to the uneven surface of the aluminum member that has been modified to aluminum hydroxide and has formed a surface nanostructure to form a film that bonds with the aluminum member. In a bonding process, the film is bonded to the resin member.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a composite member, and to a composite member. [Background technology]

[0002] Patent Document 1 discloses a method for manufacturing a composite member. This method produces a composite member by joining a base material and a resin member. Micro- or nano-order irregularities are formed on the surface of the base material. The resin member penetrates into the micro- or nano-order irregularities and solidifies, resulting in a stronger anchor effect than in the case of millimeter-order irregularities. As a result, composite members produced by this method have excellent joining strength. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 141381 Summary of the Invention [Problem to be solved by the invention]

[0004] Aluminum is lighter and stronger than iron, making it a promising base material for composite members. The manufacturing method described in Patent Document 1 leaves room for improvement in terms of further improving the joining strength and airtightness of composite members using aluminum as the base material. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a method for manufacturing a composite member in which an aluminum member and a resin member are bonded together. The manufacturing method includes a blasting process, a surface hydroxylation process, a coating process, and a bonding process. In the blasting process, the surface of the aluminum member is blasted to form irregularities on the surface of the aluminum member. In the surface hydroxylation process, the surface of the aluminum member on which the irregularities have been formed is hydrothermally treated to modify the irregular surface to aluminum hydroxide and form a surface nanostructure on the irregular surface. In the coating process, a binder containing a triazine thiol derivative is supplied to the irregular surface of the aluminum member that has been modified to aluminum hydroxide and has formed a surface nanostructure, forming a coating that bonds to the aluminum member. In the bonding process, the coating and the resin member are bonded together.

[0006] According to this manufacturing method, the surface of the aluminum member is blasted. In the blasting process, the natural oxide film formed on the surface of the aluminum member is thinned (removed) by the blasting process. The blasting process forms irregularities on the surface of the aluminum member. In the surface hydroxylation process, the surface of the aluminum member with the irregularities formed thereon is hydrothermally treated, modifying the irregular surface to aluminum hydroxide and forming a surface nanostructure on the irregular surface. This modification imparts functional groups of aluminum hydroxide (e.g., hydroxy groups) to the irregularities on the surface of the aluminum member. Then, in the coating formation process, a binder containing a triazine thiol derivative is supplied to the surface of the aluminum member, forming a coating that bonds with the aluminum member modified to aluminum hydroxide. This combines three effects: the coating penetrates into the irregularities on the surface of the aluminum member; the surface nanostructure in the irregular surface layer increases the contact surface area between the aluminum member and the coating, and the coating penetrates into the surface nanostructure; and the functional groups present on the irregular surface are molecularly bonded to the triazine thiol derivative contained in the coating. The organic bonding of these three components creates a synergistic effect that cannot be achieved by simply adding the effects of each component, resulting in a strong bond. Then, in the bonding process, a resin component is bonded to the surface of the aluminum component on which the coating is formed. The resin component is firmly bonded by molecular bonding between the functional groups present on its surface and the triazine thiol derivative contained in the coating. Sharp edges of the unevenness created by the blasting process are removed in the surface hydroxylation process and firmly bonded to the coating as described above. Therefore, this manufacturing method also has the additional benefit of making it less likely for the coating to break from sharp edges. Thus, a composite component is produced in which the aluminum component and the resin component are firmly and tightly bonded via the coating through chemical bonding via molecular bonding and mechanical bonding via the anchor effect over a large surface area. The tightly bonded composite component is highly airtight and has high thermal conductivity at the bonding interface, making it highly practical. Therefore, according to this method for manufacturing a composite member, a composite member having excellent bonding strength and airtightness can be manufactured.

[0007] In one embodiment, the surface nanostructure may have a plurality of pores with a pore size of 10 nm or more but less than 1000 nm, and the thickness of the surface nanostructure may be 0.01 μm or more and 1 μm or less. In this case, the resin component enters the plurality of pores formed in the surface nanostructure and solidifies, thereby providing an anchoring effect. Therefore, in this manufacturing method, the surface of the aluminum component is formed with a surface nanostructure by the surface hydroxylation process, and the surface can be changed into a shape that has high adhesiveness to the coating and the resin component compared to an aluminum component that does not undergo the surface hydroxylation process.

[0008] In one embodiment, the blasting process may involve spraying abrasives having a particle diameter of 30 μm to 710 μm and sharp protrusions at a spray pressure of 0.5 MPa to 2.0 MPa. This manufacturing method can appropriately remove the natural oxide film formed on the surface of the aluminum member and then form irregularities on the surface of the aluminum member. Therefore, this manufacturing method can form a uniform surface nanostructure on the surface of the aluminum member in the surface hydroxylation process and appropriately exert the anchoring effect.

[0009] In one embodiment, the hydrothermal treatment in the surface hydroxylation step may involve reacting the surface of the aluminum member with pure water at a temperature of 70° C. or higher and 100° C. or lower.

[0010] In one embodiment, the electrical conductivity of the pure water may be 0.054 μS / cm or more and 10 μS / cm or less. Pure water with low electrical conductivity has a low impurity content. This manufacturing method uses pure water with the above-mentioned electrical conductivity in the surface hydroxylation step, thereby preventing impurities other than aluminum hydroxide from remaining on the surface of the aluminum member. This manufacturing method thereby prevents impurities from removing functional groups present on the surface of the aluminum member, thereby achieving strong molecular bonding.

[0011] In one embodiment, the surface hydroxylation step may involve cleaning the surface of the aluminum member with water and modifying the surface of the aluminum member to aluminum hydroxide. The presence of organic contaminants on the surface of the aluminum member may reduce the wettability of the coating and the resin member, and may also impair the chemical bonding between the surface of the aluminum member and the coating and the resin member. In this manufacturing method, the surface of the aluminum member is cleaned with the water used for modifying the surface to aluminum hydroxide. Therefore, this manufacturing method can prevent a decrease in bonding strength due to organic contaminants.

[0012] In one embodiment, the aluminum hydroxide may include at least one of diaspore, boehmite, pseudoboehmite, bayerite, norstrandite, gibbsite, and doillite.

[0013] In one embodiment, the triazine thiol derivative may have at least one functional group selected from the group consisting of a primary amine, a secondary amine, a tertiary amine, an epoxy group, a hydroxyl group, a thiol group, an azide group, and an alkyl group. In this case, in the coating formation step, a coating is formed in which the triazine thiol derivative is bonded to the functional groups present on the surface of the aluminum member modified to aluminum hydroxide. Then, in the bonding step, the triazine thiol derivative contained in the coating is bonded to the functional groups present on the surface of the resin member, and the resin member is bonded to the surface of the aluminum member on which the coating is formed. In this way, the coating is molecularly bonded to the aluminum member modified to aluminum hydroxide and the resin member, respectively, by the functional groups of the triazine thiol derivative, thereby being firmly bonded.

[0014] In one embodiment, the joining step may join the resin member to the surface of the aluminum member by injection molding, thermocompression molding, press molding, or ultrasonic bonding, which makes it possible to easily join the resin member to the surface of the aluminum member in this manufacturing method.

[0015] According to another aspect of the present disclosure, there is provided a composite member comprising: an aluminum member having a surface irregularity formed thereon; a coating containing a triazine thiol derivative and bonded to the surface of the aluminum member; and a resin member bonded to the coating, wherein the irregularity has a surface nanostructure formed thereon, the surface nanostructure being formed of aluminum hydroxide.

[0016] In this composite member, an aluminum member has a surface with irregularities. A surface nanostructure is formed on the irregularities. The surface nanostructure is formed of aluminum hydroxide. The coating is bonded to the aluminum member by bonding between the triazine thiol derivative contained in the coating and the functional groups of the aluminum hydroxide present on the surface of the aluminum member. This combines three effects: the coating penetrates into the irregularities on the surface of the aluminum member; the surface nanostructure in the irregular surface layer increases the contact surface area between the aluminum member and the coating, allowing the coating to penetrate into the surface nanostructure; and the functional groups present on the irregular surface are molecularly bonded to the triazine thiol derivative contained in the coating. The organic bonding of these three components creates a synergistic effect that cannot be achieved by simply adding the effects of each component, resulting in a strong bond. A resin member is then bonded to the surface of the aluminum member on which the coating is formed. The resin member is strongly bonded, for example, by molecular bonding between the functional groups present on its surface and the triazine thiol derivative contained in the coating. Furthermore, sharp portions of the irregularities formed on the surface of the aluminum member are scraped off by the formation of a surface nanostructure (formation of aluminum hydroxide), and are firmly bonded to the coating as described above. Therefore, this manufacturing method also has the additional effect of making it less likely for the coating to break from sharp portions. As described above, the composite member has the aluminum member and the resin member firmly and tightly bonded via the coating through chemical bonding by molecular bonding and mechanical bonding by the anchor effect over a large surface area. The tightly bonded composite member has high airtightness and high thermal conductivity at the bonding interface, making it highly practical. Therefore, this composite member can improve the bonding strength and airtightness between the aluminum member and the resin member.

[0017] In one embodiment, the surface of the aluminum member is substantially free of phosphorus, and the aluminum hydroxide may include at least one of boehmite, pseudoboehmite, diaspore, bayerite, norstrandite, gibbsite, and doillite. In this case, since no phosphorus remains on the surface of the aluminum member, it can be said that the functional groups present on the surface of the aluminum member are not deprived of these elements, and the functional groups present on the surface of the aluminum member and the triazine thiol derivative contained in the coating are molecularly bonded. Therefore, this composite member has a structure that improves the bonding strength and airtightness between the aluminum member and the resin member.

[0018] In one embodiment, the triazine thiol derivative may have at least one functional group selected from the group consisting of a primary amine, a secondary amine, a tertiary amine, an epoxy group, a hydroxyl group, a thiol group, an azide group, and an alkyl group. In this case, a coating is formed in the composite member by bonding the triazine thiol derivative to functional groups present on the surface of the aluminum member formed from aluminum hydroxide. The triazine thiol derivative contained in the coating then bonds to functional groups present on the surface of the resin member, bonding the resin member to the surface of the aluminum member via the coating. In this way, the coating is firmly bonded to the aluminum member formed from aluminum hydroxide and the resin member through molecular bonding via the functional groups of the triazine thiol derivative.

[0019] In one embodiment, the surface of the aluminum member may be substantially free of magnesium and sodium. In this case, since no magnesium or sodium remains on the surface of the aluminum member, it can be said that the functional groups present on the surface of the aluminum member are molecularly bonded to the triazine thiol derivative contained in the coating without being deprived of the functional groups present on the surface of the aluminum member by these elements. Therefore, this composite member has a structure that improves the bonding strength and airtightness between the aluminum member and the resin member.

[0020] In one embodiment, the surface of the aluminum member may be substantially free of iron and calcium. In this case, since no iron or calcium remains on the surface of the aluminum member, the functional groups present on the surface of the aluminum member are not deprived of these elements, and the functional groups present on the surface of the aluminum member and the triazine thiol derivative contained in the coating are molecularly bonded. Therefore, this composite member has a structure that improves the bonding strength and airtightness between the aluminum member and the resin member.

[0021] In one embodiment, the arithmetic mean slope of the surface of the aluminum component bonded to the coating may be 0.17 or more and 0.50 or less. By using an aluminum component having a surface with an arithmetic mean slope of 0.17 or more and 0.50 or less, the composite component can increase the surface area of ​​the aluminum component and appropriately exhibit the anchoring effect.

[0022] In one embodiment, the root mean square slope of the surface of the aluminum member bonded to the coating may be 0.27 or more and 0.60 or less. By using an aluminum member having a surface with a root mean square slope of 0.27 or more and 0.60 or less, the composite member can increase the surface area of ​​the aluminum member and appropriately exhibit the anchor effect. [Effects of the Invention]

[0023] According to one aspect and embodiment of the present disclosure, a method for manufacturing a composite member having excellent bonding strength and airtightness, and a composite member having excellent bonding strength and airtightness are provided. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a perspective view showing a composite member according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the composite member taken along line II-II in FIG. [Figure 3] FIG. 3 is a conceptual diagram of the composite member of FIG. 2. [Figure 4]FIG. 2 is a conceptual diagram of a blasting device used in the manufacturing method of the composite member according to the embodiment. [Figure 5] FIG. 2 is a diagram illustrating the configuration of a blasting device used in the manufacturing method of a composite member according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the injection nozzle of FIG. 5. [Figure 7] FIG. 2 is a top view of a mold used for injection molding. [Figure 8] FIG. 8 is a cross-sectional view of the mold taken along line VIII-VIII in FIG. 7. [Figure 9] 1 is a flowchart of a method for manufacturing a composite member according to an embodiment. [Figure 10] This is a conceptual diagram of blast processing. [Figure 11] FIG. 10 is a diagram illustrating scanning in blast processing. [Figure 12] 1A to 1C are diagrams illustrating a manufacturing process of a composite material. [Figure 13] 1 shows the results of a composition analysis of the surface of an aluminum member. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, an embodiment will be described with reference to the drawings. In the following description, the same or equivalent elements are denoted by the same reference numerals, and duplicated explanations will be omitted. In addition, "bonding strength" in this embodiment may be described as "shear strength." The abrasives in this embodiment are members sprayed during blasting, and are, for example, abrasive grains of ceramics (alumina, silicon carbide, etc.). Unless otherwise specified, the particle diameter of the abrasives in this embodiment will be expressed as the average particle diameter (D50).

[0026] [Composite material] FIG. 1 is a perspective view showing a composite member 1 according to an embodiment. As shown in FIG. 1, the composite member 1 is a member formed by joining multiple members together. For example, the composite member 1 includes an aluminum member 2, a coating 3 bonded to the aluminum member 2, and a resin member 4 bonded to the coating 3. The aluminum member 2 is, for example, a plate-shaped member. The coating 3 is interposed between the aluminum member 2 and the resin member 4 and is in direct contact with their respective surfaces. In FIG. 1, the resin member 4 is bonded to part or all of the surface of the aluminum member 2 via the coating 3, forming a lap joint structure. The material of the aluminum member 2 is not limited and may be, for example, A5052 or ADC12. The material of the resin member 4 is a resin such as polybutylene terephthalate, polyphenylene sulfide, polyamide, liquid crystal polymer, polypropylene, or acrylonitrile butadiene styrene.

[0027] FIG. 2 is a cross-sectional view of the composite member 1 taken along line II-II in FIG. 1. As shown in FIG. 2, the aluminum member 2 has a surface 2a having irregularities 2b formed on a portion thereof. Hereinafter, the surface 2a of the aluminum member 2 refers to the outermost surface layer of the aluminum member 2, regardless of whether the surface has been processed or modified. Note that the surface 2a of the aluminum member 2 is also referred to as the surface 2c of the irregularities 2b when specifically describing the surface layer of the irregularities 2b. The irregularities 2b are micro-scale irregularities. Micro-scale irregularities are irregularities having a height difference of 1 μm or more but less than 1000 μm. FIG. 3 is a conceptual diagram of the composite member shown in FIG. 2. As shown in FIG. 3, the irregularities 2b have inclined portions 2e that slope from the convex portions to the concave portions of the irregularities 2b. The inclined portions 2e contribute to bonding with the coating 3 (described below) and the resin member 4, and serve as stress concentration areas that contribute to shear strength. The arithmetic mean roughness Ra of the irregularities 2b as defined in JIS B0601 (1994) may be 0.7 μm or more and 5.0 μm or less. The arithmetic mean slope RΔa of the irregularities 2b as defined in JIS B0601 (1994) may be 0.17 or more and 0.50 or less, as calculated by the formula shown in FIG. 3. The root mean square slope RΔq of the irregularities 2b as defined in JIS B0601 (1994) may be 0.27 or more and 0.60 or less. A modified layer of aluminum hydroxide (e.g., a surface nanostructure as described below) is formed on the surface 2c of the irregularities 2b. The resin member 4 penetrates into and is fixed to the irregularities 2b, thereby providing an anchor effect.

[0028] Referring again to FIG. 2, a surface nanostructure 2d is formed on the irregularities 2b of the aluminum member 2. The surface nanostructure 2d is formed of aluminum hydroxide. For example, the surface nanostructure 2d formed of aluminum hydroxide is formed on the surface 2c of the irregularities 2b formed on the aluminum member 2. That is, the surface nanostructure 2d is exposed on the surface 2a of the aluminum member 2. The surface nanostructure 2d is a film made of aluminum hydroxide and is sponge-like (porous). The surface nanostructure 2d has a plurality of pores with a pore size of 10 nm or more and less than 1000 nm. The thickness of the surface nanostructure 2d is 0.01 μm or more and 1 μm or less. The aluminum hydroxide is an aluminum hydroxide and is a compound of aluminum having a hydroxy group. The aluminum hydroxide formed on the surface 2a of the aluminum member 2 includes at least one of diaspore, boehmite, pseudoboehmite, bayerite, norstrandite, gibbsite, and doillite. The aluminum hydroxide formed on the surface 2a of the aluminum member 2 may be formed of any one of diaspore, boehmite, pseudo-boehmite, bayerite, norstrandite, gibbsite, and doillite. The aluminum hydroxide formed on the surface 2a of the aluminum member 2 may be formed of a plurality of types of aluminum hydroxide selected from diaspore, boehmite, pseudo-boehmite, bayerite, norstrandite, gibbsite, and doillite.

[0029] Between the aluminum member 2 and the coating 3, impurities other than elements constituting the material of the aluminum member 2 and the material of the coating 3 are excluded. For example, the surface 2a of the aluminum member 2 is substantially free of phosphorus. That is, when the surface nanostructure 2d is subjected to compositional analysis by X-ray photoelectron spectroscopy, phosphorus is below the detection limit of X-ray photoelectron spectroscopy and is not detected. Furthermore, in the case of an aluminum member 2 that is substantially free of magnesium and sodium, the surface 2a of the aluminum member 2 is also substantially free of magnesium and sodium. That is, when the surface 2a of the aluminum member 2 is subjected to compositional analysis by X-ray photoelectron spectroscopy, magnesium and sodium are each below the detection limit of X-ray photoelectron spectroscopy and are not detected. Furthermore, when pure water is used to modify the aluminum member 2 into aluminum hydroxide, iron and calcium are substantially free of the surface 2a of the aluminum member 2. That is, when the surface 2a of the aluminum member 2 is subjected to compositional analysis by X-ray photoelectron spectroscopy, iron and calcium are each below the detection limit of X-ray photoelectron spectroscopy and are not detected.

[0030] The surface 2a of the aluminum member 2, which has been modified to aluminum hydroxide and has a surface nanostructure formed thereon, is covered with a coating 3. This coating 3 contains a triazine thiol derivative having at least one functional group selected from the group consisting of primary amine, secondary amine, tertiary amine, epoxy group, hydroxyl group, thiol group, azide group, and alkyl group. The coating 3 is formed from a composition containing the triazine thiol derivative. The triazine thiol derivative is a compound obtained by changing part of the structure of triazine thiol through substitution or other chemical reaction. Examples of the triazine thiol derivative contained in the coating 3 include 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-dithiol monosodium salt (TES), 6-(3-ethoxydimethylsilylpropylamino)-1,3,5-triazine-2,4-dithiol monosodium salt (MES), and 6-bis(3-triethoxysilylpropyl)amino-1,3,5-triazine-2,4-dithiol monosodium salt (B-TES). The triazine thiol derivative contained in the coating 3 may be a derivative that does not contain silane, and specifically may be 6-(4-vinylbenzyl-n-propyl)amino-1,3,5-triazine-2,4-dithiol, 1,3,5-triazine-2,4,6-trithiol, 6-dimethylamino-1,3,5-triazine-2,4-dithiol, 6-benzylamino-1,3,5-triazine-2,4-dithiol, 6-dibutylamino-1,3,5-triazine-2,4-dithiol, 6-dioctylamino-1,3,5-triazine-2,4-dithiol, 6-didodecaylamino-1,3,5-triazine-2,4-dithiol, 6-diallylamino-1,3,5-triazine-2,4-dithiol, 6-dioleylamino-1,3,5-triazine-2,4-dithiol, or a salt thereof.

[0031] The triazine thiol derivative of the coating 3 chemically bonds with the functional group of the aluminum hydroxide present on the surface 2a of the aluminum member 2. The functional group present in the triazine thiol derivative of the coating 3 is at least one of primary amine, secondary amine, tertiary amine, epoxy group, hydroxyl group, thiol group, azide group, and alkyl group. The functional group of the aluminum hydroxide present on the surface of the aluminum member 2 is a hydroxyl group. For example, if the triazine thiol derivative of the coating 3 is TES and a hydroxyl group is present on the surface 2a of the aluminum member 2, the alkyl group contained in the TES reacts with the hydroxyl group present on the surface 2a of the aluminum member 2, resulting in a chemical bond. This bonds the aluminum member 2 with the coating 3, and the surface 2a of the aluminum member 2, on which the irregularities 2b and surface nanostructure 2d are formed, is covered with the coating 3. The coating 3 bonds with the surface 2a of the aluminum member 2 with a portion of the coating 3 entering the pores of the irregularities 2b and surface nanostructure 2d on the surface 2a of the aluminum member 2.

[0032] The resin member 4 bonds to the coating 3 with a portion of it entering the irregularities 2b on the surface 2a of the aluminum member 2 and the pores of the surface nanostructure 2d. The triazine thiol derivative of the coating 3 chemically bonds with the functional group present on the surface of the resin member 4. Here, the functional group present in the triazine thiol derivative of the coating 3 is, for example, a thiol group. The functional group present in the resin member 4 is, for example, a hydrocarbon group or a hydroxyl group. For example, if the triazine thiol derivative of the coating 3 is TES, the thiol group of the TES reacts (copolymerizes) with the hydrocarbon group contained in the resin member 4, replacing the carbon atom in the resin member 4 with a sulfur atom, thereby bonding the coating 3 and the resin member 4. The resin member 4 is bonded to the aluminum member 2 by the chemical bond formed by the coating 3.

[0033] As described above, in the composite member 1 according to this embodiment, micro-scale irregularities 2b are formed on a portion of the surface 2a of the aluminum member 2 that contacts the resin member 4. Furthermore, a surface nanostructure 2d is formed on the irregularities 2b. The surface nanostructure 2d is made of aluminum hydroxide. A plurality of pores with a pore size of 10 nm or more and less than 1000 nm are formed in the surface nanostructure 2d. The triazine thiol derivative contained in the coating 3 chemically bonds with the functional groups of the aluminum hydroxide present on the surface 2a of the aluminum member 2, thereby bonding the coating 3 to the aluminum member 2. This combines three effects: the coating 3 penetrates into the irregularities 2b on the surface 2a of the aluminum member 2; the surface nanostructure 2d on the surface layer of the irregularities 2b increases the contact surface area between the aluminum member 2 and the coating 3, and the coating 3 penetrates into the surface nanostructure 2d; and the functional groups present on the surface 2c of the irregularities 2b are molecularly bonded to the triazine thiol derivative contained in the coating. The organic bonding of these three components creates a synergistic effect that cannot be achieved by simply adding the effects of each component, resulting in a strong bond. The resin component 4 is bonded to the surface 2a of the aluminum component 2 via the coating 3. The resin component 4 is strongly bonded to the surface 2a of the aluminum component 2 through molecular bonding between the functional groups present on the surface and the triazine thiol derivative contained in the coating 3. Even if the asperities 2b formed on the surface 2a of the aluminum component 2 have sharp edges, they are scraped away by the formation of the surface nanostructure 2d (the formation of an aluminum hydroxide film) and are firmly bonded to the coating 3 as described above. Therefore, this composite component 1 also has the additional effect of making the coating 3 and the resin component 4 less susceptible to fracture originating from sharp edges. Furthermore, the formation of the surface nanostructure 2d at the inclined portions 2e, which are stress-concentrated areas in the asperities 2b, provides an anchoring effect, and the aforementioned chemical bonding forces act to achieve higher bonding strength and airtightness. As described above, in the composite member 1, the aluminum member 2 and the resin member 4 are firmly and tightly bonded via the coating 3 by chemical bonding through molecular bonding and mechanical bonding through the anchor effect over a large surface area.The tightly bonded composite member 1 has high airtightness and high thermal conductivity at the bonded interface, making it highly practical. Therefore, this composite member 1 can improve the bond strength and airtightness between the aluminum member 2 and the resin member 4. If airtightness is not ensured between the aluminum member and the resin member, for example, water may enter between the aluminum member and the resin member from the outside, corroding the interface and significantly reducing the bond strength and airtightness. Even if a composite member maintains high bond strength alone, it is impractical if high airtightness is not ensured, since the stability of the interface is not ensured. The composite member 1 of this embodiment ensures both high bond strength and high airtightness due to the anchoring effect of the irregularities 2b and the surface nanostructure 2d, and the strong chemical bonding strength between the aluminum member 2 and the coating 3 and between the coating 3 and the resin member 4. Therefore, the stability of the interface between the aluminum member 2 and the resin member 4 in the composite member 1 is maintained at a high level. Therefore, the composite member 1 is practical and highly reliable, and can be used for a variety of applications. For example, the composite material 1 can be applied to devices that require high airtightness and high thermal conductivity. For example, in the sealing portion between a resin terminal block and an aluminum conductor used in semiconductor manufacturing, sealing work was conventionally performed after the fact using a sealing resin such as an epoxy resin liquid, but by applying the composite material 1 of this embodiment, high airtightness can be ensured and heat dissipation and cooling of the aluminum conductor becomes easier.

[0034] In the composite material 1, the surface 2a of the aluminum member 2 is substantially free of phosphorus, and the aluminum hydroxide contains at least one of boehmite, pseudo-boehmite, diaspore, bayerite, norstrandite, gibbsite, and doillite. Since no phosphorus remains on the surface 2a of the aluminum member 2, it can be said that the functional groups present on the surface 2a of the aluminum member 2 are not taken over by these elements, and that the functional groups present on the surface 2a of the aluminum member 2 and the triazine thiol derivative contained in the coating 3 are molecularly bonded. Therefore, the composite material 1 has a structure that improves the bonding strength and airtightness between the aluminum member 2 and the resin member 4.

[0035] The triazine thiol derivative in the composite member 1 has at least one functional group selected from the group consisting of primary amine, secondary amine, tertiary amine, epoxy group, hydroxyl group, thiol group, azide group, and alkyl group. In this case, the composite member 1 is provided with a coating 3 formed by bonding the triazine thiol derivative with functional groups present on the surface 2a of the aluminum member 2 formed from aluminum hydroxide. The triazine thiol derivative contained in the coating 3 then bonds with functional groups present on the surface of the resin member 4, bonding the resin member 4 to the surface of the aluminum member 2 on which the coating 3 is formed. In this way, the coating 3 is molecularly bonded to the aluminum member 2 formed from aluminum hydroxide and the resin member 4 via the functional groups of the triazine thiol derivative, thereby firmly bonding the coating 3 to each of them.

[0036] In the composite material 1, the surface 2a of the aluminum member 2 is substantially free of magnesium and sodium. Because no magnesium or sodium remains on the surface 2a of the aluminum member 2, it can be said that the functional groups present on the surface 2c of the aluminum member 2 are molecularly bonded to the triazine thiol derivative contained in the coating 3, without these elements removing the functional groups present on the surface 2a of the aluminum member 2. Therefore, the composite material 1 has a structure that improves the bonding strength and airtightness between the aluminum member 2 and the resin member 4.

[0037] In the composite material 1, the surface 2a of the aluminum member 2 is substantially free of iron and calcium. Because no iron or calcium remains on the surface 2a of the aluminum member 2, it can be said that the functional groups present on the surface 2a of the aluminum member 2 are not taken over by these elements, and that the functional groups present on the surface 2a of the aluminum member 2 are molecularly bonded to the triazine thiol derivative contained in the coating 3. Therefore, this composite material 1 has a structure that improves the bonding strength and airtightness between the aluminum member 2 and the resin member 4.

[0038] In the composite material 1, the arithmetic mean slope RΔa of the surface 2a of the aluminum member 2 that bonds with the coating 3 is 0.17 or more and 0.50 or less. By using an aluminum member 2 having a surface 2a with an arithmetic mean slope RΔa of 0.17 or more and 0.50 or less, the composite material 1 can increase the surface area of ​​the aluminum member 2 and appropriately exhibit the anchor effect.

[0039] In the composite member 1, the root-mean-square slope RΔq of the surface 2a of the aluminum member 2 that bonds with the coating 3 is 0.27 or more and 0.60 or less. By using an aluminum member 2 having a surface 2a with a root-mean-square slope RΔq of 0.27 or more and 0.60 or less, the composite member 1 can increase the surface area of ​​the aluminum member 2 and appropriately exhibit the anchor effect.

[0040] [Manufacturing method for composite materials] An outline of an apparatus used in the manufacturing method of the composite material 1 will be described. First, an apparatus for blasting the surface 2a of the aluminum member 2 will be described. Any type of blasting apparatus may be used, such as a gravity type (suction type) air blasting apparatus, a direct pressure type (pressurized type) air blasting apparatus, or a centrifugal type blasting apparatus. The manufacturing method according to this embodiment uses, as an example, a so-called direct pressure type (pressurized type) air blasting apparatus. Figure 4 is a conceptual diagram of a blasting apparatus 10 used in the manufacturing method of the composite material 1. The blasting apparatus 10 includes a processing chamber 11, a spray nozzle 12, a storage tank 13, a pressurized chamber 14, a compressed gas supplier 15, and a dust collector (not shown).

[0041] A spray nozzle 12 is housed inside the treatment chamber 11, and blast processing is performed on a workpiece (here, an aluminum member 2) in the treatment chamber 11. The abrasives sprayed by the spray nozzle 12 fall to the bottom of the treatment chamber 11 together with dust. The fallen abrasives are supplied to a storage tank 13, and the dust is supplied to a dust collector. The abrasives stored in the storage tank 13 are supplied to a pressurizing chamber 14, and the pressurizing chamber 14 is pressurized by a compressed gas supply device 15. The abrasives stored in the pressurizing chamber 14 are supplied to the spray nozzle 12 together with the compressed gas. In this way, the workpiece is blast processed while the abrasives are circulated.

[0042] Fig. 5 is a diagram illustrating the configuration of a blasting device 10 used in the manufacturing method of the composite material 1 according to the embodiment. The blasting device 10 shown in Fig. 5 is the direct pressure type blasting device shown in Fig. 4. In Fig. 5, the wall surface of the processing chamber 11 is partially omitted.

[0043] As shown in Figure 5, the blast processing device 10 includes a storage tank 13 for abrasives and a pressurized chamber 14 formed in an airtight structure to which a compressed gas supply machine 15 is connected, a constant-volume supply unit 16 connected to the storage tank 13 within the pressurized chamber 14, a spray nozzle 12 connected to the constant-volume supply unit 16 via a connecting pipe 17, a processing table 18 that moves while holding a workpiece below the spray nozzle 12, and a control unit 19.

[0044] The control unit 19 controls the components of the blasting apparatus 10. The control unit 19 includes, for example, a display unit and a processing unit. The processing unit is a general computer having a CPU, a memory unit, and the like. The control unit 19 controls the supply amount of compressed gas from the compressed gas supply device 15, which supplies compressed gas to the storage tank 13 and the pressurizing chamber 14, based on the set injection pressure and injection speed. The control unit 19 also controls the injection position of the injection nozzle 12 based on the set distance between the workpiece and the nozzle and the workpiece scanning conditions (speed, feed pitch, number of scans, etc.). As a specific example, the control unit 19 controls the position of the injection nozzle 12 using the scanning speed (X direction) and feed pitch (Y direction) set before the blasting process. The control unit 19 controls the position of the injection nozzle 12 by moving the processing table 18 that holds the workpiece.

[0045] FIG. 6 is a cross-sectional view of the injection nozzle 12 of FIG. 5. The injection nozzle 12 has an injection pipe holder 120, which is the main body. The injection pipe holder 120 is a cylindrical member having an internal space through which the injection material and compressed gas pass. One end of the injection pipe holder 120 is an injection material inlet 123, and the other end is an injection material outlet 122. The injection pipe holder 120 has an inner wall surface tapered from the injection material inlet 123 side toward the injection material outlet 122, forming a conical convergence acceleration section 121 with an inclination angle. A cylindrical injection pipe 124 is connected to the injection pipe holder 120 on the injection material outlet 122 side. The convergence acceleration section 121 tapers from the middle of the cylindrical section of the injection pipe holder 120 toward the injection pipe 124. This forms a compressed gas flow 115.

[0046] The connecting pipe 17 of the blasting device 10 is connected to the abrasive inlet 123 of the injection nozzle 12. This forms an abrasive path in which the storage tank 13, the constant volume supply unit 16 in the pressurizing chamber 14, the connecting pipe 17, and the injection nozzle 12 are sequentially connected.

[0047] In the blasting device 10 configured as described above, compressed gas is supplied from the compressed gas supply machine 15 to the storage tank 13 and the pressurizing chamber 14 at a supply amount controlled by the control unit 19. Then, by a constant pressure flow force, the abrasives in the storage tank 13 are metered in a constant amount by the metering supply unit 16 in the pressurizing chamber 14, supplied to the injection nozzle 12 via the connecting pipe 17, and injected from the injection pipe 124 of the injection nozzle 12 onto the processing surface of the workpiece. In this way, a constant amount of abrasives is always injected onto the processing surface of the workpiece. Then, the injection position of the injection nozzle 12 on the processing surface of the workpiece is controlled by the control unit 19, and the workpiece is blasted.

[0048] The sprayed abrasives and cutting powder generated by the blasting process are sucked up by a dust collector (not shown). A classifier (not shown) is arranged on the path from the processing chamber 11 to the dust collector, and separates the abrasives into reusable abrasives and other fine powder (abrasives that have become too large to be reused and cutting powder generated by the blasting process). The reusable abrasives are stored in a storage tank 13 and are supplied again to the spray nozzle 12. The fine powder is collected by the dust collector.

[0049] Next, injection molding will be described. Insert molding is used here as the injection molding. In insert molding, an insert part is attached to a predetermined mold, and resin is injected and held for a predetermined time to solidify. Residual stress in the resin is then removed by heat treatment. FIG. 7 is a top view of a mold used for injection molding. FIG. 8 is a cross-sectional view of the mold taken along line VIII-VIII in FIG. 7. As shown in FIGS. 7 and 8, a mold 20 includes a mold body 21 (an upper mold 21a and a lower mold 21b). Between the upper mold 21a and the lower mold 21b, there are provided a space 22 for attaching an insert part (here, an aluminum member 2) and a space 23 into which resin is injected. A resin injection port is provided on the top surface of the upper mold 21a. The resin injection port is connected to the space 23 via a sprue 24, a runner 25, and a gate 26. A pressure sensor 27 and a temperature sensor 28 are provided in the space 23 to detect the pressure and temperature of the space 23. Based on the detection results of pressure sensor 27 and temperature sensor 28, parameters of the molding machine (not shown) are adjusted to produce a molded product. The parameters include mold temperature, resin temperature during filling, filling pressure, injection rate, holding time, pressure during holding, heat treatment temperature, heat treatment time, etc. The molded product molded in mold 20 has a lap joint structure that is joined over a specified area.

[0050] Next, a series of steps in a manufacturing method for the composite member 1 will be described. FIG. 9 is a flowchart of the manufacturing method MT for the composite member 1 according to the embodiment. As shown in FIG. 9, first, in a preparation step (S10), a predetermined abrasive is loaded into a blasting device 10. The particle diameter of the abrasive is, for example, 30 μm to 710 μm. As the particle diameter of the abrasive decreases, the mass decreases and the inertial force decreases. Therefore, if the particle diameter of the abrasive is smaller than 30 μm, it becomes difficult to form the desired shape of the irregularities 2b. Furthermore, industrially used aluminum members 2 are generally stored in the atmosphere, and their surfaces are covered with a non-uniform natural aluminum oxide film with a thickness of 60 nm to 300 nm. Therefore, the presence of the natural aluminum oxide film may result in non-uniform surface treatment when chemically etching the surface or laser processing the surface. To uniformly modify the surface 2a of the aluminum member 2 in the surface hydroxylation step described below, the natural aluminum oxide film needs to be a film with a thickness of approximately 30 nm or less. However, if the particle diameter of the abrasive exceeds 710 μm, it becomes difficult to remove the natural oxide film of the aluminum to a thickness of approximately 30 nm or less. Therefore, it is not possible to sufficiently remove the natural oxide film formed on the surface 2a of the aluminum member 2 before performing the blasting process step (S12) described below. The particle diameter of the abrasive that can achieve both the formation of the irregularities 2b and the removal of the natural oxide film of the aluminum is 30 μm to 710 μm. The material of the abrasive is, for example, alumina. The abrasive has, for example, sharp-angled protrusions.

[0051] In the preparation step (S10), the control unit 19 of the blasting device 10 acquires blasting conditions. The control unit 19 acquires the blasting conditions based on an operator's operation or information stored in the memory unit. The blasting conditions include the injection pressure, injection speed, nozzle distance, and workpiece scanning conditions (speed, feed pitch, and number of scans). The injection pressure is, for example, 0.5 to 2.0 MPa. The lower the injection pressure, the lower the inertial force. Therefore, if the injection pressure is less than 0.5 MPa, it becomes difficult to form the desired shape of the irregularities 2b. The higher the injection pressure, the higher the inertial force. Therefore, the abrasives are more likely to be crushed upon collision with the aluminum member 2. As a result, problems occur, such as (1) poor processing efficiency because the collision energy is dissipated in areas other than the formation of the irregularities 2b, and (2) excessive wear of the abrasives, making the process uneconomical. These problems become more pronounced when the injection pressure exceeds 2.0 MPa. The control unit 19 manages the blasting conditions to precisely control the size, depth, density, etc. of the irregularities 2b on the surface 2a of the aluminum member 2 on the order of microns or nanons. The blasting conditions may include conditions for specifying the area to be blasted. In this case, selective surface treatment is possible.

[0052] Next, the blasting device 10 performs the following series of processes as the blasting process (S12). First, the aluminum member 2 to be blasted is set on the processing table 18 in the processing chamber 11. The aluminum member 2 is substantially free of magnesium and sodium. Next, the control unit 19 activates a dust collector (not shown). The dust collector reduces the pressure inside the processing chamber 11 to a negative pressure based on a control signal from the control unit 19. Next, the injection nozzle 12 injects abrasives as a two-phase solid-gas flow of compressed air at an injection pressure ranging from 0.5 to 2.0 MPa based on a control signal from the control unit 19. Next, the control unit 19 activates the processing table 18 to move the aluminum member 2 into the two-phase solid-gas flow (below the injection nozzle in FIG. 5). FIG. 10 is a conceptual diagram of the blasting process. As shown in FIG. 10, abrasives are injected from the injection nozzle 12 onto a partial region 2f of the surface 2a of the aluminum member 2. Here, the control unit 19 continues to operate the processing table 18, causing the jet of water to trace a predetermined trajectory relative to the aluminum member 2. FIG. 11 is a diagram illustrating the scanning of the blasting process. As shown in FIG. 11, the control unit 19 operates the processing table 18 according to a scanning trajectory L at a feed pitch P. FIG. 12 is a diagram illustrating the manufacturing process of a composite member. As shown in FIG. 12(A), the aluminum member 2 before the blasting process has no irregularities 2b formed thereon. By the operation of the processing table 18 described above, the desired micro-order irregularities 2b are formed on the surface 2a of the aluminum member 2, as shown in FIG. 12(B).

[0053] By blasting the surface 2a of the aluminum member 2 with abrasive particles having a particle diameter of 30 μm to 710 μm at a blast pressure of 0.5 to 2.0 MPa, the desired micro-scale irregularities 2b are formed. The arithmetic mean roughness Ra of the irregularities 2b, as defined in JIS B0601 (1994), may be 0.7 μm to 5.0 μm. The arithmetic mean slope RΔa of the irregularities 2b, as defined in JIS B0601 (1994), may be 0.17 to 0.50. The root-mean-square slope RΔq of the irregularities 2b, as defined in JIS B0601 (1994), may be 0.27 to 0.60. Furthermore, the natural oxide film on the surface 2a of the aluminum member 2 has a thickness of, for example, approximately 9 nm or less. After the operation of the blasting device 10 is stopped, the aluminum member 2 is removed, and the blasting process is completed. As shown in Figure 12(B), the unevenness 2b on the surface 2a of the aluminum member 2 after the blasting process has sharp protrusions.

[0054] Next, in the surface hydroxylation step (S14), the surface 2a of the aluminum member 2 on which the irregularities 2b are formed is subjected to a hydrothermal treatment to modify the surface 2c of the irregularities 2b into aluminum hydroxide and form a surface nanostructure 2d on the surface 2c of the irregularities 2b. In the hydrothermal treatment in the surface hydroxylation step, the surface 2a of the aluminum member 2 is reacted with heated water. In the hydrothermal treatment, the aluminum member 2 on which the irregularities 2b are formed is immersed in pure water heated to 70°C or higher and 100°C or lower for a predetermined period of time. The pure water used in the surface hydroxylation step (S14) has an electrical conductivity of 0.054 μS / cm or higher and 10 μS / cm or lower. The pure water is substantially free of magnesium, sodium, and phosphorus. Furthermore, the pure water is substantially free of iron and calcium. That is, the magnesium, sodium, phosphorus, iron, and calcium in the pure water are each below the detection limit of X-ray photoelectron spectroscopy. As a result, the surface 2c of the irregularities 2b is modified mainly to boehmite, and the surface nanostructure 2d is formed. The use of this pure water prevents impurities other than aluminum hydroxide from remaining on the surface 2a of the aluminum member 2. In particular, because magnesium, sodium, phosphorus, iron, and sodium are not present on the surface 2a of the aluminum member 2, the functional groups present on the surface 2a of the aluminum member 2 are not deprived of these elements, allowing molecular bonding between the functional groups present on the surface 2a of the aluminum member 2 and the triazine thiol derivative contained in the coating 3 described below. The aluminum hydroxide formed on the surface 2a of the aluminum member 2 is not limited to boehmite, but may be any one of diaspore, pseudoboehmite, bayerite, norstrandite, gibbsite, and doillite. The aluminum hydroxide formed on the surface 2a of the aluminum member 2 may be formed of multiple types of aluminum hydroxide selected from diaspore, boehmite, pseudoboehmite, bayerite, norstrandite, gibbsite, and doillite. As shown in FIG. 12(C), a surface nanostructure 2d is formed on the surface 2c of the unevenness 2b. The surface nanostructure 2d is a film made of aluminum hydroxide and has a sponge-like (porous) structure, and has a plurality of pores with a pore diameter of 10 nm or more and less than 1000 nm.The thickness of the surface nanostructure 2d is 0.01 μm or more and 1 μm or less. As a result, a spongy (porous) surface nanostructure 2d is formed on the sharp portions (acute protrusions) of the irregularities 2b formed in the blasting process step (S12) and is modified into aluminum hydroxide, which has the additional effect of making it less likely that the coating 3 and resin member 4 (described below) that penetrate into the irregularities 2b will break from the sharp portions.

[0055] After the blasting process (S12), the surface 2a of the aluminum member 2 may have fine particles, such as a natural oxide film peeled off by the blasting process or abrasives, adhering to it. For example, the fine particles may be adsorbed to the surface 2a of the aluminum member 2 by the electrostatic force of the aluminum member 2, or may be impaled on the surface 2a of the aluminum member 2 by the spray force of the abrasives from the spray nozzle 12. In this case, in the surface hydroxylation process (S14), the surface 2a of the aluminum member 2 may be washed with water. This removes the fine particles from the surface 2a of the aluminum member 2 and reduces the surface carbon concentration. The surface carbon concentration may be actively reduced by combining hydrothermal treatment and ultrasonic cleaning. That is, in the hydrothermal treatment, the surface 2a of the aluminum member 2 is washed with water (pure water) and converted to aluminum hydroxide. For example, the aluminum member 2 is immersed in pure water heated to 70°C or higher and 100°C or lower, and ultrasonic waves are applied to the pure water. This allows the hydrothermal treatment and surface cleaning to be performed simultaneously.

[0056] Next, in the coating formation step (S16), a binder containing a triazine thiol derivative is applied to the surface 2c of the irregularities 2b of the aluminum member 2, which has been modified to aluminum hydroxide and has a surface nanostructure 2d formed thereon, to form a coating 3 in which the triazine thiol derivative bonds with functional groups present on the surface 2a of the aluminum member 2 modified to aluminum hydroxide. As shown in Figure 12 (D), the irregularities 2b and surface nanostructure 2d on the surface 2a of the hydrothermally treated aluminum member 2 are coated with the coating 3. The triazine thiol derivative has at least one functional group selected from primary amine, secondary amine, tertiary amine, epoxy group, hydroxyl group, thiol group, azide group, and alkyl group. In the coating formation step (S16), the surface 2a of the aluminum member 2 is reacted with the binder containing the triazine thiol derivative by, for example, immersion, spray coating, or brush coating.

[0057] First, the formation of the coating 3 by immersion treatment will be described. The binder containing the triazine thiol derivative is liquid. In the immersion treatment, the surface 2a of the aluminum member 2 modified to aluminum hydroxide is immersed in the liquid binder for a predetermined time. The triazine thiol derivative in the binder chemically bonds with functional groups (e.g., hydroxy groups) on the surface 2a of the aluminum member 2. In this way, the liquid binder containing the triazine thiol derivative can be brought into contact with the surface 2a of the aluminum member 2 to bond them, and the coating 3 is formed on the surface 2a of the aluminum member 2.

[0058] Next, the formation of the coating 3 by spray coating will be described. In the spray coating process, for example, a liquid binder containing a triazine thiol derivative is stored in a spray container. The spray container is capable of spraying the liquid binder. In the spray coating process, the liquid binder is sprayed onto the surface 2a of the aluminum member 2 that has been modified to aluminum hydroxide using the spray container, and adheres to the surface 2a of the aluminum member 2. In this way, the liquid binder containing the triazine thiol derivative can be brought into contact with the surface 2a of the aluminum member 2, and the coating 3 is formed on the surface 2a of the aluminum member 2.

[0059] Next, the formation of the coating 3 by a brush coating process will be described. In the brush coating process, for example, a liquid binder containing a triazine thiol derivative is stored in a storage container, and a brush is immersed in the storage container to allow the liquid binder to adhere to the brush. In the brush coating process, the liquid binder is applied to the surface 2a of the aluminum member 2, which has been modified to aluminum hydroxide, using a brush, and adhered to the surface 2a of the aluminum member 2. In this way, the liquid binder containing the triazine thiol derivative can be brought into contact with the surface 2a of the aluminum member 2, and the coating 3 is formed on the surface 2a of the aluminum member 2.

[0060] In the coating formation step (S16), the surface 2a of the aluminum member 2 is reacted with a binder containing a triazine thiol derivative to form the coating 3, and then ultrasonic cleaning with pure water may be performed to properly remove excess binder remaining around the coating 3.

[0061] Next, a molding machine (not shown) performs molding using the above-described mold 20 as a joining step (S18). First, the mold 20 is opened, the aluminum member 2 on which the coating 3 is formed is installed in the space 22, and the mold 20 is closed. Then, the molding machine injects molten resin having a set resin temperature into the mold 20 through the resin injection port. The injected resin passes through the sprue 24, the runner 25, and the gate 26 and fills the space 23. The molding machine controls the resin filling pressure and injection rate based on the detection results of the pressure sensor 27. The molding machine controls the mold temperature to a set value based on the detection results of the temperature sensor 28. The molding machine also controls the pressure to a set value for a set retention time based on the detection results of the pressure sensor 27. Thereafter, the molding machine performs heat treatment based on the set heat treatment temperature and heat treatment time. At this time, as shown in (E) of Figure 12, functional groups (e.g., thiol groups, azide groups, amino groups, etc.) contained in the coating 3 copolymerize with functional groups in the resin member 4, thereby bonding the coating 3 and the resin member 4. Thereafter, the molding machine opens the mold 20 and removes the composite member 1 in which the aluminum member 2, coating 3, and resin member 4 are integrated. When the joining step (S18) is completed, the flowchart shown in Figure 9 ends.

[0062] As described above, according to the manufacturing method MT of the composite member 1, the surface 2a of the aluminum member 2 is blasted. In the blasting process (S12), the natural oxide film formed on the surface 2a of the aluminum member 2 is thinned (removed) by the blasting process. Micro-order irregularities 2b are formed on the surface 2a of the aluminum member 2 (the surface exposed by the blasting process) by the blasting process. In the surface hydroxylation process (S14), the surface 2a of the aluminum member 2 on which the irregularities 2b are formed (the surface 2c of the irregularities 2b) is modified to aluminum hydroxide, and a surface nanostructure 2d is formed on the surface 2c of the irregularities 2b. The surface nanostructure 2d is formed from aluminum hydroxide. This modification imparts functional groups of aluminum hydroxide (e.g., hydroxy groups) to the irregularities 2b of the aluminum member 2. Then, in the coating formation process (S16), a binder containing a triazine thiol derivative is applied to the surface 2a of the aluminum member 2, and a coating 3 is formed by bonding the triazine thiol derivative with functional groups present on the surface 2a (asperities 2b) of the aluminum member 2 modified to aluminum hydroxide. This combines three actions: the coating 3 penetrates into the asperities 2b of the aluminum member 2; the surface nanostructure 2d on the surface 2c of the asperities 2b increases the contact surface area between the aluminum member 2 and the coating 3, and the coating 3 penetrates into the surface nanostructure 2d; and the functional groups present on the surface 2c of the asperities 2b are molecularly bonded to the triazine thiol derivative contained in the coating 3. The organic bonding of these three components creates a synergistic effect that cannot be achieved by simply adding the effects of each component, resulting in a strong bond. Then, in the bonding process (S18), a resin member 4 is bonded to the surface of the aluminum member 2 on which the coating 3 has been formed. The resin member 4 is firmly bonded by molecular bonding between the functional groups present on its surface and the triazine thiol derivative contained in the coating 3. The sharp portions of the irregularities 2b formed by the blasting process (S12) are scraped off in the surface hydroxylation process (S14) and are firmly bonded to the coating 3 as described above.Therefore, this manufacturing method MT has the additional effect of making it difficult for sharp portions (acute-angled protrusions) to cause fractures of the coating 3 and the resin member 4. As described above, a composite member 1 is manufactured in which the aluminum member 2 and the resin member 4 are firmly and tightly bonded via the coating 3 through chemical bonding by molecular bonding and mechanical bonding by the anchor effect over a large surface area. The tightly bonded composite member 1 has high airtightness and high thermal conductivity at the bonding interface, making it highly practical. Therefore, this manufacturing method MT for the composite member 1 can manufacture a composite member 1 with excellent bonding strength and airtightness. However, if airtightness is not ensured between the aluminum member and the resin member, for example, water may enter between the aluminum member and the resin member from the outside, corroding the interface and significantly reducing the bonding strength and airtightness. Even if a composite member maintains high bonding strength, it is not practical unless high airtightness is ensured, because the stability of the interface is not ensured. In the composite member 1 of this embodiment, both high bonding strength and high airtightness are ensured by the anchoring effect of the irregularities 2b and the surface nanostructure 2d, and the strong chemical bonding strength between the aluminum member 2 and the coating 3, and between the coating 3 and the resin member 4. This maintains high stability at the interface between the aluminum member 2 and the resin member 4 in the composite member 1. Therefore, the composite member 1 is practical and highly reliable, and can be used for a variety of applications. For example, the composite member 1 can be applied to devices requiring high airtightness and high thermal conductivity. For example, in the sealing portion between a resin terminal block and an aluminum conductor used in semiconductor manufacturing, a sealing resin such as an epoxy resin liquid was previously used to perform post-sealing. However, by applying the composite member 1 of this embodiment, high airtightness can be ensured and heat dissipation and cooling of the aluminum conductor can be facilitated.

[0063] According to manufacturing method MT, a plurality of pores having a pore diameter of 10 nm or more but less than 1000 nm are formed in the surface nanostructure 2d, and the thickness of the surface nanostructure 2d is 0.01 μm or more and 1 μm or less. In this case, the resin member 4 enters the plurality of pores formed in the surface nanostructure 2d and solidifies, thereby achieving an anchoring effect. Therefore, in manufacturing method MT, the surface 2a of the aluminum member 2 is formed with the surface nanostructure 2d by the surface hydroxylation step (S14), and thus the surface 2a can be changed into a shape with higher adhesiveness between the coating 3 and the resin member 4 compared to an aluminum member 2 that does not undergo the surface hydroxylation step (S14).

[0064] According to manufacturing method MT, in the blasting process (S12), abrasives with particle diameters of 30 μm to 710 μm and sharp protrusions are sprayed at a spray pressure of 0.5 MPa to 2.0 MPa. This manufacturing method MT appropriately removes the natural oxide film formed on the surface 2a of the aluminum component 2 and forms irregularities 2b on the surface 2a of the aluminum component 2. This allows a uniform surface nanostructure 2d to be formed on the surface 2a of the aluminum component 2 in the surface hydroxylation process (S14), while also properly exerting the anchoring effect. Here, when spherical abrasives such as glass beads are used for blasting, dimple-like irregularities are formed on the surface 2a of the aluminum component 2. These irregularities are difficult to fit with the resin component 4, making it difficult for the resin component 4 to be retained by the irregularities. Therefore, even if a composite component is formed, the bonding strength is reduced. Using abrasives with sharp protrusions in the blasting process allows for spike-like irregularities 2b (shapes with sharp protrusions). The spike-shaped irregularities 2b are formed on the surface 2a of the aluminum member 2, and the resin member 4 fits into the irregularities 2b. Therefore, the resin member 4 fitted into the spike-shaped irregularities 2b exhibits high bonding strength with the aluminum member 2.

[0065] According to manufacturing method MT, the hydrothermal treatment in the surface hydroxylation step (S14) involves reacting the surface 2a of the aluminum member 2 with pure water at a temperature of 70°C or higher and 100°C or lower. The surface modification of the aluminum member 2 can be achieved by the above-mentioned treatment. As a result, if the aluminum member 2 is substantially free of magnesium and sodium, the interface (surface 2a) of the aluminum member 2 in the composite member 1 manufactured by manufacturing method MT will be substantially free of magnesium, sodium, and phosphorus.

[0066] According to manufacturing method MT, the electrical conductivity of the pure water is 0.054 μS / cm or more and 10 μS / cm or less. Pure water with low electrical conductivity has a low impurity content. This manufacturing method MT uses pure water with the above-mentioned electrical conductivity in the surface hydroxylation step (S14), thereby preventing impurities other than aluminum hydroxide from remaining on the surface 2a of the aluminum member 2. Examples of impurities include magnesium, sodium, phosphorus, iron, and calcium. This makes it possible to prevent impurities from removing functional groups present on the surface 2a of the aluminum member 2, thereby achieving strong molecular bonding.

[0067] According to manufacturing method MT, in the surface hydroxylation step (S14), the surface 2a of the aluminum member 2 is washed with water and modified to aluminum hydroxide. If organic contaminants are present on the surface 2a of the aluminum member 2, the wettability of the coating 3 and the resin member 4 may decrease, and the chemical bond between the surface 2a of the aluminum member 2 and the coating 3 and the resin member 4 may be impaired. In manufacturing method MT, the surface 2a of the aluminum member 2 is washed with the water used for modifying the surface 2a to aluminum hydroxide. Therefore, manufacturing method MT can suppress a decrease in bonding strength caused by organic contaminants.

[0068] According to production method MT, the aluminum hydroxide includes at least one of diaspore, boehmite, pseudoboehmite, bayerite, norstrandite, gibbsite, and doillite. The surface 2a (surface nanostructure 2d) of the aluminum member 2, which is formed by combining multiple types of aluminum hydroxides among the above-mentioned aluminum hydroxides, is formed by heating water at a lower temperature in the surface hydroxylation step (S14) than the surface nanostructure 2d formed by any one type of aluminum hydroxide among the above-mentioned aluminum hydroxides.

[0069] According to manufacturing method MT, the triazine thiol derivative has at least one functional group selected from the group consisting of primary amine, secondary amine, tertiary amine, epoxy group, hydroxyl group, thiol group, azide group, and alkyl group. In this case, in the coating formation step (S16), a coating 3 is formed by bonding the triazine thiol derivative with functional groups present on the surface 2a of the aluminum member 2 modified to aluminum hydroxide. Then, in the bonding step (S18), the triazine thiol derivative contained in the coating 3 bonds with functional groups present on the surface of the resin member 4, and the resin member 4 is bonded to the surface 2a of the aluminum member 2 on which the coating 3 is formed. In this way, the coating 3 is molecularly bonded to the aluminum member 2 modified to aluminum hydroxide and the resin member 4 by the functional groups of the triazine thiol derivative, and is firmly bonded to each other.

[0070] According to manufacturing method MT, the joining step (S18) may join the resin member 4 to the surface 2a of the aluminum member 2 by injection molding, thermocompression molding, press molding, or ultrasonic bonding. This makes it possible for manufacturing method MT to easily join the resin member 4 to the surface 2a of the aluminum member 2 via the coating 3.

[0071] Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modifications other than the present embodiment without departing from the spirit of the present invention.

[0072] [Modifications of aluminum and resin components] Although the aluminum member 2 and the resin member 4 in the above embodiment are shown as plate-shaped members, the shape is not limited thereto and any shape that allows them to come into contact with each other can be adopted. The resin member 4 in the above embodiment is in contact with a portion of the surface 2a of the aluminum member 2, but it may be in contact with the entire surface 2a of the aluminum member 2.

[0073] The material of the resin member is not limited to the above-mentioned examples. For example, the material of the resin member may be a thermoplastic fiber-reinforced resin or a thermosetting fiber-reinforced resin. Examples of thermoplastic fiber-reinforced resins include aramid fiber-reinforced thermoplastic resins (AFRTP: Aromatic polyamide fiber-reinforced thermoplastics), carbon fiber-reinforced thermoplastic resins (CFRTP: Carbon fiber-reinforced thermoplastics), and glass fiber-reinforced thermoplastic resins (GFRTP: Glass fiber-reinforced thermoplastics). Examples of thermosetting fiber-reinforced resins include aramid fiber-reinforced plastics (AFRP: Aromatic polyamide fiber-reinforced plastics), carbon fiber-reinforced plastics (CFRP: Carbon fiber-reinforced plastics), and glass fiber-reinforced plastics (GFRP: Glass fiber-reinforced plastics).

[0074] [Modifications of injection molding] The injection molding is not limited to insert molding, but may be outsert molding. [Example]

[0075] [Size of injection material] First, the thickness of the natural oxide film on the aluminum component 2 was measured before the blasting process (S12). Auger electron spectroscopy (AES) was used to perform a depth profile analysis of the natural oxide film. Because oxide and metal components are simultaneously detected near the oxide / metal interface, they were separated using spectral synthesis to determine the thickness of the natural oxide film. The thickness of the natural oxide film was 72 nm. Next, the thickness of the natural oxide film on the aluminum component 2 was measured after the blasting process (S12) using the blasting equipment shown in Figures 4 to 6. When abrasives with a median particle diameter of 600 μm to 710 μm were used, the thickness of the natural oxide film was 13 nm. When abrasives with a median particle diameter of 41 μm to 50 μm (maximum particle diameter 127 μm or less, average particle diameter 57 μm ± 3 μm) were used, the thickness of the natural oxide film was 9 nm. Therefore, it was confirmed that the natural oxide film on the surface 2a of the aluminum member 2 can be removed by using abrasives having a particle size of at least 710 μm or less.

[0076] [Checking the surface condition of aluminum components] The blasting process (S12) was carried out using the blasting device shown in Figures 4 to 6. The aluminum member used was an aluminum plate (JIS (Japanese Industrial Standards): A5052). For the blasting process, alumina was used as the material, and the abrasive particles had a central particle diameter of 106 μm to 125 μm. The blasting pressure was 1.0 MPa. After the blasting process, the surface was observed using a field emission scanning electron microscope (FE-SEM).

[0077] Next, a surface hydroxylation step (S14) was carried out. The blasted aluminum member was immersed in pure water at 90°C for 2 minutes. The surface was then observed using a field emission scanning electron microscope (FE-SEM). This confirmed that the surface of the aluminum member after the surface hydroxylation step (S14) had multiple pores with diameters of 10 nm or more and less than 1000 nm.

[0078] [Confirming the composition of the surface of aluminum components] [Example: Surface-treated product] The blasting process step (S12) was carried out using the blasting device shown in Figures 4 to 6. The aluminum member used was an aluminum plate (JIS: A5052). For the blasting process, alumina was used as the material, and the abrasive had a central particle diameter of 106 μm to 125 μm. The blasting pressure was 1.0 MPa. Subsequently, the surface hydroxylation process (S14) was carried out. The blasted aluminum member was immersed in pure water at 90°C for 2 minutes. [Comparative Example: Untreated Product] The aluminum plate (JIS: A5052) was used, which had not undergone the blasting process (S12) and the surface hydroxylation process (S14).

[0079] The surface compositions of the surface-treated and untreated samples were analyzed by attenuated total reflectance (ATR) using a Fourier transform infrared spectrophotometer (FT-IR). The analysis results are shown in Figure 13.

[0080] FIG. 13 shows the results of a composition analysis of the surface of an aluminum member. In the graph shown in FIG. 13, the horizontal axis represents wavenumber and the vertical axis represents absorbance. The waveform data shown at the top of the graph represents the composition analysis results of the surface-treated product, while the waveform data shown at the bottom represents the composition analysis results of the untreated product. As shown in FIG. 13, in the waveform data of the untreated product, peaks due to carbon contamination (e.g., CH4) appeared at wavenumbers of 3960 m-1, 3930 m-1, and 2873 m-1, and a peak due to aluminum oxide (Al-O) appeared at wavenumber 946 m-1. No peak due to boehmite was observed. In contrast, in the data of the surface-treated product, the peak due to carbon contamination (e.g., CH4) and the peak due to aluminum oxide (Al-O) that were present before treatment disappeared, and peaks due to boehmite appeared at wavenumbers of 3268 m-1 and 3113 m-1. This confirms that the surface treatment removed organic contamination from the surface of the aluminum member and formed aluminum hydroxide.

[0081] [Confirmation of surface carbon concentration] The surface carbon concentration of the aluminum member 2 that had undergone the surface hydroxylation step (S14) was measured and compared with that of an untreated aluminum member. X-ray photoelectron spectroscopy (XPS) was used for the measurements. As a result, the surface carbon concentration of the untreated aluminum member 2 that had undergone the surface hydroxylation step (S14) was 40 at%, while the surface carbon concentration of the aluminum member 2 that had undergone the surface hydroxylation step (S14) was 8 at%. In this way, it was confirmed that the hydrothermal treatment had a cleaning effect as a secondary effect.

[0082] [Checking shear strength] Example 1 and Comparative Examples 1 to 4 were prepared and the shear strength was checked. [Example 1] The blasting process (S12) was performed using the blasting device shown in Figures 4 to 6. The aluminum member was an aluminum plate (JIS: ADC12). The blasting process used alumina with sharp protrusions and abrasives with a central particle diameter of 106 μm to 125 μm. The blasting pressure was 1.0 MPa. As a result, irregularities were formed on the surface of the aluminum member, with the arithmetic mean roughness Ra, arithmetic mean slope RΔa, and root-mean-square slope RΔq, as specified in JIS B0601 (1994), being 2.5 μm, 0.35, and 0.42, respectively. Subsequently, a hydrothermal treatment was performed in the surface hydroxylation process (S14). The blasted aluminum member was immersed in pure water at 90°C for 2 minutes. For the hydrothermal treatment, ion-exchanged water with an electrical conductivity of 0.05 μS / cm was used. Subsequently, the immersion process of the coating formation process (S16) was performed. The aluminum member that had undergone the surface hydroxylation process was immersed in the molecular bonding agent for 1 minute. A-TES (0.1% aqueous solution of triazine-based molecular bonding agent) manufactured by Io Chemical Research Institute was used as the molecular bonding agent for forming the coating. After the coating was formed, ultrasonic cleaning with pure water was performed for 1 minute. Subsequently, the bonding process (S18) was performed. Using the mold shown in Figures 7 and 8, the resin member was bonded to the aluminum member by injection molding. The resin member was made of polyphenylene sulfide resin (PPS). During injection, the mold temperature was 150°C, the injection speed was 20 mm / s, the injection pressure was 53 MPa or more and 93 MPa or less, and the injection time was 0.56 s. During holding, the holding pressure was 80 MPa, and the holding time was 8 s. For the shear strength test piece, the area of ​​the bonded portion between the aluminum member and the resin member was 50 mm2, measuring 5 mm x 10 mm. 2 In the airtightness test piece, the aluminum member was formed so that its inner diameter was 20 mm. The resin member was joined to the aluminum member under the above conditions so that its outer diameter was 24 mm. The width of the joint between the aluminum member and the resin member was 2 mm.

[0083] [Example 2] In Example 2, an aluminum plate (JIS: A5052) was used as the aluminum member. Other conditions, including the blasting process (S12), the surface hydroxylation process (S14), the coating process (S16), and the joining process (S18), were the same as in Example 1.

[0084] [Example 3] In Example 3, an aluminum plate (JIS: ADC12) that had undergone the same blasting process (S12), surface hydroxylation process (S14), and coating process (S16) as in Example 1 was used as the aluminum member. In the joining process (S18), a carbon fiber reinforced thermoplastic resin (CFRTP: Carbon Fiber Reinforced Thermo Plastics), which is a fiber-reinforced resin, was used as the resin member. In the joining process (S18), the aluminum member on which the coating was formed and the resin member were joined by press molding rather than injection molding. When holding the press molding (when the mold was closed), the mold temperature was 220°C, the holding pressure was 5 MPa, and the holding time was 300 s. The conditions for the shear strength test piece and the airtightness test piece were the same as in Example 1.

[0085] [Comparative Example 1] In Comparative Example 1, an aluminum plate (JIS: ADC12) that had undergone the same blasting process (S12) as in Example 1 was used as the aluminum member. Unlike the surface hydroxylation process in Example 1, the blasted aluminum member was immersed in 90°C water for 2 minutes in the hydrothermal treatment. Ordinary tap water containing metal ions was used for the hydrothermal treatment. The coating process (S16) and bonding process (S18) were the same as in Example 1.

[0086] Comparative Example 2 In Comparative Example 2, an aluminum plate (JIS: A5052) that had undergone the same blasting process (S12) as in Example 2 was used as the aluminum member. Unlike the surface hydroxylation process in Example 2, the blasted aluminum member was immersed in 90°C water for 2 minutes in the hydrothermal treatment. Ordinary tap water containing metal ions was used for the hydrothermal treatment. The coating process (S16) and bonding process (S18) were the same as in Examples 1 and 2.

[0087] Comparative Example 3 In Comparative Example 3, the same aluminum plate (JIS: ADC12) as in Example 1 was used as the aluminum member. The blasting process was carried out using the blasting device shown in Figures 4 to 6. For the blasting process, alumina without sharp protrusions was used as the material, and the abrasives had a central particle diameter of 106 μm to 125 μm. The blasting pressure was 1.0 MPa. In this case, irregularities were formed on the surface of the aluminum member with arithmetic mean roughness Ra, arithmetic mean slope RΔa, and root mean square slope RΔq of 2.5 μm, 0.16, and 0.42, respectively, as specified in JIS B0601 (1994). The surface hydroxylation process (S14), coating formation process (S16), and joining process (S18) were carried out in the same manner as in Example 1.

[0088] Comparative Example 4 In Comparative Example 4, the same aluminum plate (JIS: ADC12) as in Example 1 was used as the aluminum member. The blasting process was carried out using the blasting device shown in Figures 4 to 6. For the blasting process, glass beads were used as the material, and the abrasives had a central particle diameter of 106 μm to 125 μm. The blasting pressure was 1.0 MPa. At this time, irregularities were formed on the surface of the aluminum member, with the arithmetic mean roughness Ra, arithmetic mean slope RΔa, and root mean square slope RΔq specified in JIS B0601 (1994) being 2.5 μm, 0.15, and 0.20, respectively. The surface hydroxylation process (S14), coating formation process (S16), and joining process (S18) were the same as in Example 1.

[0089] Comparative Example 5 In Comparative Example 5, an aluminum plate (JIS: A5052) was used as the aluminum member, which had not been subjected to the blasting process (S12) but had been subjected to the same surface hydroxylation process (S14) as in Example 1. The coating process (S16) and the joining process (S18) were the same as in Example 1.

[0090] [Bonding strength evaluation] The shear strengths of Examples 1 to 3 and Comparative Examples 1 to 5 prepared under the above conditions were measured. The evaluation device was used in accordance with a test method in accordance with ISO 19095-2 (overlapped test piece (Type B)). The shear strength of Example 1 was 42 MPa, the shear strength of Example 2 was 44 MPa, the shear strength of Example 3 was 37 MPa, the shear strength of Comparative Example 1 was 8 MPa, the shear strength of Comparative Example 2 was 6 MPa, and the shear strength of Comparative Example 3 was 10 MPa. In Comparative Example 4 and Comparative Example 5, the aluminum member and the resin member were not joined, so the shear strength could not be measured.

[0091] By comparing Example 1 with Comparative Example 1 and Example 2 with Comparative Example 2, it was confirmed that using pure water in the hydrothermal treatment in the surface hydroxylation step (S14) contributes significantly to improving shear strength. Pure water contains fewer impurities (e.g., magnesium, sodium, phosphorus, iron, and calcium), so the impurities do not remove the functional groups (hydroxy groups) of the aluminum hydroxide formed on the surface of the aluminum member. Therefore, more hydroxy groups of the aluminum hydroxide formed on the surface of the aluminum member can react with the functional groups of the triazine thiol derivative, which is thought to improve the shear strength between the aluminum member and the coating and the shear strength of the composite member.

[0092] By comparing Examples 1 and 2 with Example 3, it was confirmed that injection molding as the joining method (S18) contributes to improving shear strength. Example 3 uses fiber-reinforced resin, but its shear strength is lower than that of Examples 1 and 2, which do not use fiber-reinforced resin. This is thought to be because, although the fiber-reinforced resin improves impact absorption performance, it does not contribute significantly to the shear force between the aluminum member and the resin member. Furthermore, it is thought that injection molding can more appropriately join aluminum members and resin members than press molding.

[0093] Comparing Example 1 with Comparative Example 3 and Example 1 with Comparative Example 4, it was confirmed that the formation of irregularities on the surface of the aluminum component, in which the arithmetic mean slope RΔa and the root mean square slope RΔq were controlled to be 0.17 to 0.50 and 0.27 to 0.60, respectively, by the blasting process (S12), significantly contributed to improving shear strength. It was also confirmed that even if the arithmetic mean roughness Ra was the same, shear strength was significantly reduced when the arithmetic mean slope RΔa and the root mean square slope RΔq were not within the above-mentioned ranges. The resin component could penetrate the steeply angled irregularities formed by the blasting process, and even when an external force was applied, the resin component interfered with the irregularities and did not break. Therefore, it is believed that Example 1 had higher shear strength than Comparative Examples 3 and 4.

[0094] By comparing Comparative Example 3 and Comparative Example 4, it was confirmed that when the injection material was alumina, the values ​​of the arithmetic mean slope RΔa and the root mean square slope RΔq were higher than when the injection material was glass beads, contributing to the proper formation of the composite member. When the injection material was alumina, the unevenness formed on the surface of the aluminum member was spike-shaped, whereas when the injection material was glass beads, the unevenness formed on the surface of the aluminum member was dimple-shaped. Therefore, when the injection material was alumina, the anchor effect was more likely to occur between the aluminum member and the coating and resin member than when the injection material was glass beads, which is thought to have led to the proper formation of the composite member (the aluminum member and the resin member were joined).

[0095] By comparing Example 1 with Comparative Example 5 and by comparing Comparative Example 3 with Comparative Example 5, it was confirmed that the blasting process (S12) contributes to the proper formation of the composite member. In other words, it was confirmed that the composite member would not be properly formed even if only the surface hydroxylation process (S14), the coating process (S16), and the bonding process (S18) were properly performed.

[0096] [Airtightness evaluation] The airtightness of Examples 1 to 3 and Comparative Examples 1 to 5 prepared under the above conditions was measured. The evaluation device was used to measure the degree of helium (He) leakage using a test method conforming to ISO 19095-2 (overlap test piece for adhesion characteristics (Type D)). The airtightness (amount of helium leakage) of Examples 1 to 3 was 5.0 × 10 -7 Pa·m 3 / s, whereas the airtightness (leakage of helium) of Comparative Examples 1 to 3 was less than 5.0 × 10 -5 Pa·m 3 / s or more. In Comparative Examples 4 and 5, the aluminum member and the resin member were not joined, and therefore it was not possible to measure the airtightness (amount of helium leakage).

[0097] By comparing Example 1 with Comparative Example 1 and Example 2 with Comparative Example 2, it was confirmed that using pure water in the hydrothermal treatment in the surface hydroxylation step (S14) contributes significantly to improving airtightness. Pure water contains fewer impurities (e.g., magnesium, sodium, phosphorus, iron, and calcium), so the impurities do not remove the functional groups (hydroxy groups) of the aluminum hydroxide formed on the surface of the aluminum member. Therefore, more hydroxy groups of the aluminum hydroxide formed on the surface of the aluminum member can react with the functional groups of the triazine thiol derivative, allowing the aluminum member and the coating to bond more closely, which is thought to have improved the airtightness of the composite member.

[0098] By comparing Example 1 with Comparative Example 3 and Example 1 with Comparative Example 4, it was confirmed that the formation of irregularities on the surface of the aluminum member by the blasting process (S12), in which the arithmetic mean slope RΔa and the root mean square slope RΔq were controlled to be 0.17 or more and 0.50 or less, and 0.27 or more and 0.60 or less, respectively, significantly contributed to improving airtightness. It was also confirmed that even if the arithmetic mean roughness Ra was the same, if the arithmetic mean slope RΔa and the root mean square slope RΔq were not within the above-mentioned ranges, airtightness was significantly reduced. The resin member could penetrate the steeply angled irregularities formed by the blasting process, and the resin member tightly interlocked with the infiltrated irregularities. Therefore, it is believed that Example 1 has higher airtightness than Comparative Examples 3 and 4. [Explanation of symbols]

[0099] 1...composite member, 2...aluminum member, 2a, 2c...surface, 2b...concave and convex, 2d...surface nanostructure, 3...coating, 4...resin member, 10...blasting device, 11...processing chamber, 12...spray nozzle, 13...storage tank, 14...pressurization chamber, 15...compressed gas supply machine, 16...quantitative supply unit, 17...connecting pipe, 18...processing table, 19...control unit, 20...mold, 21...mold body.

Claims

1. A method for manufacturing a composite member in which an aluminum member and a resin member are joined, a blasting process for blasting the surface of the aluminum member to form irregularities on the surface of the aluminum member; a surface hydroxylation step of hydrothermally treating the surface of the aluminum member on which the irregularities have been formed to modify the irregular surface into aluminum hydroxide and form a surface nanostructure on the irregular surface; a coating formation step of supplying a binder containing a triazine thiol derivative to the uneven surface of the aluminum member that has been modified into aluminum hydroxide and has a surface nanostructure formed thereon, thereby forming a coating that bonds to the aluminum member; a joining step of joining the coating and the resin member; Including, In the hydrothermal treatment in the surface hydroxylation step, a hydrothermal treatment is carried out on the surface of the aluminum member by reacting it with pure water at a temperature of 70°C or higher and 100°C or lower, The electrical conductivity of the pure water is 0.054 μS / cm or more and 10 μS / cm or less. Manufacturing method for composite components.

2. The surface nanostructure has a plurality of pores each having a pore diameter of 10 nm or more and less than 1000 nm, The method for producing a composite member according to claim 1 , wherein the thickness of the surface nanostructure is 0.01 μm or more and 1 μm or less.

3. 3. The method for manufacturing a composite member according to claim 1 or 2, wherein the blasting step involves spraying abrasives having a particle diameter of 30 μm or more and 710 μm or less and having sharp protrusions at a spray pressure of 0.5 MPa or more and 2.0 MPa or less to perform the blasting process.

4. 4. The method for producing a composite member according to claim 1, wherein in the surface hydroxylation step, the surface of the aluminum member is washed with water and the surface of the aluminum member is modified to the aluminum hydroxide.

5. The method for producing a composite member according to any one of claims 1 to 4, wherein the aluminum hydroxide includes at least one of diaspore, boehmite, pseudoboehmite, bayerite, norstrandite, gibbsite, and doillite.

6. The method for producing a composite member according to any one of claims 1 to 5, wherein the triazine thiol derivative has at least one functional group selected from the group consisting of a primary amine, a secondary amine, a tertiary amine, an epoxy group, a hydroxyl group, a thiol group, an azide group, and an alkyl group.

7. The method for manufacturing a composite member according to any one of claims 1 to 6, wherein the joining step joins the resin member to the surface of the aluminum member on which the coating is formed by injection molding, thermocompression molding, press molding, or ultrasonic bonding.

8. an aluminum member having a surface formed with irregularities; a coating containing a triazine thiol derivative and bonded to the surface of the aluminum member; a resin member bonded to the coating; Equipped with a surface nanostructure is formed on the irregularities, and the surface nanostructure is formed of aluminum hydroxide containing at least one of boehmite, pseudoboehmite, diaspore, bayerite, norstrandite, gibbsite, and doillite; The surface of the aluminum member is substantially free of phosphorus, magnesium, sodium, iron, and calcium. Composite material.

9. The composite member according to claim 8 , wherein the triazine thiol derivative has at least one functional group selected from the group consisting of a primary amine, a secondary amine, a tertiary amine, an epoxy group, a hydroxyl group, a thiol group, an azide group, and an alkyl group.

10. 10. The composite member according to claim 8, wherein the arithmetic mean gradient on the surface of the aluminum member bonded to the coating is 0.17 or more and 0.50 or less.

11. The composite member according to any one of claims 8 to 10, wherein the root mean square slope of the surface of the aluminum member bonded to the coating is 0.27 or more and 0.60 or less.

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