Resin-metal composite

Abstract

The present invention relates to a resin metal composite body which has a configuration wherein a metal member (X) and a resin member (Y) that is formed of a thermoplastic resin composition (A) that is mainly composed of a thermoplastic resin are bonded to each other, and which has excellent bonding strength. More specifically, the present invention provides a resin metal composite body which has a configuration wherein a surface of the metal member (X), said surface having recesses and projections, and the resin member (Y) are bonded to each other, and which is characterized in that: the thermoplastic resin composition (A) contains a thermoplastic resin and a fibrous reinforcing filler; and the relational expression (1) described below is satisfied.　(1): Ra / (Fd × Wr) ≥ 0.5 (In the relational expression (1), Ra represents the arithmetic mean roughness (μm) of the surface of the metal member (X) as determined in accordance with JIS B 0601 (2001); Fd represents the average fiber diameter (μm) of the fibrous reinforcing filler; and Wr represents the value of (amount of fibrous reinforcing filler (parts by mass) in thermoplastic resin composition (A)) / (total amount of all constituent components (parts by mass) in thermoplastic resin composition (A)).)

Description

[Technical Field]

[0001] The present invention relates to a resin-metal composite having a structure in which a thermoplastic resin member, preferably a thermoplastic resin member mainly composed of polybutylene terephthalate (also referred to as "PBT"), and a metal member are joined together. [Background technology]

[0002] In recent years, in fields such as automotive and consumer electronics parts, development has been progressing toward replacing metal products with resin products, taking into consideration environmental factors such as weight reduction and recycling. Among resin products, polyester products are widely used in various equipment parts because they have excellent mechanical strength, chemical resistance, and electrical insulation properties, as well as excellent heat resistance, moldability, and recyclability. Thermoplastic polyester resins, such as polybutylene terephthalate, have excellent mechanical strength and moldability, and can be made flame-retardant, so they are widely used in electrical and electronic equipment components where fire safety is required.

[0003] However, since resin products have poor heat dissipation, the development of resin-metal composites, which are made by joining metal components such as aluminum or iron with resin components, is progressing in fields such as electrical and electronic equipment components and automotive parts. Generally, these types of resin-metal composites can be made superior to resin products in terms of strength, antistatic properties, thermal conductivity, heat dissipation, and electromagnetic shielding properties.

[0004] Regarding such resin-metal composites, for example, Patent Document 1 discloses a method for integrally molding a metal and a thermoplastic resin by in-mold molding a thermoplastic resin onto a metal substrate. Furthermore, Patent Document 2 discloses another method for manufacturing a composite of a resin component and a metal component, in which a resin is bonded to a metal component that has been subjected to a surface treatment by chemical etching by injection molding.

[0005] Patent Document 3 discloses a metal surface treatment method that exhibits excellent adhesion when bonding metals to organic polymer substances, etc., which involves performing a chemical etching treatment that forms a film on the metal surface and then chemically removing the film. Furthermore, Patent Document 4 discloses a method for manufacturing a joint between a metal substrate and a cured resin, which involves forming a zincate film on the surface of an aluminum substrate, then roughening the surface using an etching agent, and filling the resulting depressions with a resin composition. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-29669 [Patent Document 2] Japanese Patent Publication No. 2008-173967 [Patent Document 3] Japanese Patent Application Publication No. 11-293476 [Patent Document 4] Japanese Patent Publication No. 2019-99864 [Overview of the project] [Problems that the invention aims to solve]

[0007] Conventional resin-metal composites have faced challenges in expanding their applications because the bonding state between metal and resin components was not sufficiently stable. They presented particular challenges for use in automotive applications. Incidentally, as disclosed in the aforementioned Patent Documents 2 to 4, if a metal member is immersed in a chemical solution to roughen its surface and create irregularities, and then resin is filled into these irregularities by injection molding or the like, it is possible to join the metal member and the resin member by utilizing the anchoring effect of the irregularities. Moreover, since the process can be carried out regardless of the size or shape of the metal member, its applications can be broadened, and it can be used, for example, in automotive applications. In recent years, when joining metal and resin components, there has been a growing demand to further increase the joint strength while simultaneously increasing the strength of the resin component.

[0008] Therefore, the present invention relates to a resin-metal composite having a structure in which a thermoplastic resin member made of a resin composition and a metal member are joined together, and aims to provide a new resin-metal composite that can achieve a sufficiently stable bonded state and, furthermore, can increase the strength of the resin member at the same time as the bonded strength. [Means for solving the problem]

[0009] As a result of the inventors' investigations, the above problem was solved by the following means. <1> The device comprises a metal member (X) having a surface with surface irregularities and a resin member (Y) made of a thermoplastic resin composition (A), A resin-metal composite having a structure in which a surface side having surface irregularities of a metal member (X) and a resin member (Y) are joined together, wherein the thermoplastic resin composition (A) includes a thermoplastic resin and a fibrous reinforcing filler, and satisfies the following relational expression (1). Ra / (Fd×Wr)≧0.5···(1) (Note that in the above relational expression (1), Ra is the arithmetic mean roughness (μm) of the surface of the metal member (X) measured in accordance with JIS B 0601:2001, Fd is the average fiber diameter (μm) of the fibrous reinforcing filler, and Wr is the amount (parts by mass) of the fibrous reinforcing filler in the thermoplastic resin composition (A) / the total amount (parts by mass) of all constituent components in the thermoplastic resin composition (A).)

[0010] <2> The thermoplastic resin content is 30-80% by mass. <1> The resin-metal composite described above. <3> The thermoplastic resin composition (A) comprises a polyester (a-1) containing polybutylene terephthalate (also referred to as "homo-PBT") or a copolymer of polybutylene terephthalate (also referred to as "copolymer PBT") or a mixed resin thereof, and a thermoplastic resin (a-2) that is compatible with the polyester (a-1), wherein the polyester (a-1) and the thermoplastic resin (a-2) are present in a mass ratio of (a-1):(a-2)=20:80 to 80:20. <1> or <2> A metal-resin composite as described in any of the following. <4> The bonding strength between the metal member (X) and the resin member (Y), as measured in accordance with ISO 19095, is 26 MPa or more. <1> ~ <3> A resin-metal composite as described in any of the following. <5> The surface of the metal member (X) has an arithmetic mean roughness (Ra) of 0.01 to 100 μm, measured in accordance with JIS B 0601:2001. <1> ~ <4> A resin-metal composite as described in any of the following.

[0011] <6> The average fiber diameter (Fd) is 4 to 9 μm. <1> ~ <5> A resin-metal composite as described in any of the following. <7> The surface irregularities of the aforementioned metal member (X) are due to treatment with a chemical solution. <1> ~ <6> A resin-metal composite as described in any of the following. <8> The surface irregularities of the aforementioned metal member (X) are due to a coating of chemical solution forming the outermost layer. <1> ~ <7> A resin-metal composite as described in any of the following.

[0012] <9> The surface irregularities of the aforementioned metal member (X) are due to laser treatment. <1> ~ <8> A metal-resin composite as described in any of the following. <10> The thermoplastic resin composition (A) contains a low molecular weight compound (c), and the low molecular weight compound (c) contains oxidized polyethylene wax. <1> ~ <9> A resin-metal composite as described in any of the following. <11> The thermoplastic resin composition (A) contains a low molecular weight compound (c), and the acid value of the low molecular weight compound (c) is 0.01 to 40 mg / KOH. <1> ~ <10> A resin-metal composite as described in any of the following. <12>The resin-metal composite according to any one of <1> to <11>, wherein the thermoplastic resin composition contains a low molecular compound (c) and the acid value of the low molecular compound (c) is 0.5 to 20 mg / KOH. <13>The resin-metal composite according to any one of <1> to <12>, wherein the average fiber length of the fibrous reinforcing filler is 50 to 800 μm. <14>The resin-metal composite according to any one of <1> to <13>, wherein the thermoplastic resin composition (A) further contains an epoxy group-containing compound (b).

[0013] <15>The resin-metal composite according to any one of <1> to <14>, wherein the thermoplastic resin (a-2) is polyethylene terephthalate. <16>The resin member (Y) covers the peripheral edge on the back side through the side end face from the peripheral edge on the surface side of the metal member (X) having irregularities on the surface, and at the peripheral edge on the surface side and the peripheral edge on the back side of the metal member, the irregular portion of the metal member (X) and the thermoplastic resin composition of the resin member (Y) are joined. The resin-metal composite according to any one of <1> to <15>. <17>The method for manufacturing a resin-metal composite according to any one of <1> to <16>, including a step of applying a molten resin composition to the metal member (X) having irregularities on the surface by injection molding.

[0014] <18>A vehicle member comprising the resin-metal composite according to any one of <1> to <16>. <19>An electrical component comprising the resin-metal composite according to any one of <1> to <16>. <20>A housing member comprising the resin-metal composite according to any one of <1> to <16>. <21>A housing member for a smartphone comprising the metal-resin composite according to any one of <1> to <16>. <22>A housing member for a vehicle electrical component comprising the resin-metal composite according to any one of <1> to <16>.

[0015] <23>It includes a metal member (X) having a surface with irregularities and a resin member (Y) made of a polyester resin composition (A). A resin-metal composite having a structure in which a metal member (X) with an uneven surface is joined to a resin member (Y), The polyester resin composition (A) comprises a polyester (a-1) containing polybutylene terephthalate (also referred to as "homo-PBT") or a copolymer of polybutylene terephthalate (also referred to as "copolymer PBT") or a mixed resin thereof, a thermoplastic resin (a-2) compatible with the polyester (a-1), an epoxy group-containing compound (b), and a reinforcing filler (d). The polyester resin composition (A) contains the polyester (a-1) and the thermoplastic resin (a-2) in a mass ratio of (a-1):(a-2)=50:50 to 20:80. The resin-metal composite is characterized in that the reinforcing filler (d) is glass fiber with an average fiber diameter of 4 to 9 μm.

[0016] <24> The surface of the metal member (X) has an arithmetic mean roughness (Ra) of 0.01 to 100 μm, measured in accordance with JIS B 0601:2001. <23> The resin-metal composite described above. <25> The surface irregularities of the aforementioned metal member (X) are due to treatment with a chemical solution. <23> or <24> The resin-metal composite described above. <26> The surface irregularities of the aforementioned metal member (X) are due to a coating of chemical solution forming the outermost layer. <23> ~ <25> A resin-metal composite as described in any of the following.

[0017] <27> The polyester resin composition is characterized in that it contains a low molecular weight compound (c), and the low molecular weight compound (c) contains oxidized polyethylene wax. <23> ~ <26> A resin-metal composite as described in any of the following. <28> The polyester resin composition is characterized by containing a low molecular weight compound (c), the acid value of the low molecular weight compound (c) being 0.01 to 40 mg / KOH. <23> ~ <27> A resin-metal composite as described in any of the following. <29> The polyester resin composition is characterized by containing a low molecular weight compound (c), the acid value of which is 0.5 to 20 mg / KOH. <23> ~ <27> A resin-metal composite as described in any of the following. <30> The resin member (Y) covers the peripheral edge of the metal member (X), which has an uneven surface, from the front side peripheral edge to the back side peripheral edge via the side edge, and the uneven portion of the metal member (X) and the polyester resin composition of the resin member (Y) are joined at the front side peripheral edge and the back side peripheral edge of the metal member. <23> ~ <29> A resin-metal composite as described in any of the following.

[0018] <31> The step of applying the molten resin composition to the metal member (X) having irregularities on its surface is characterized by being carried out by injection molding. <23> ~ <29> A method for manufacturing a resin-metal composite as described in any of the above.

[0019] <32> <23> ~ <30> A vehicle component made of a resin-metal composite as described in any of the above. <33> <23> ~ <30> An electrical component made of a resin-metal composite as described in any of the above. <34> <23> ~ <30> A housing component made of a resin-metal composite as described in any of the above. <35> <23> ~ <30> A housing component for vehicle electrical components, made of a resin-metal composite as described in any of the above. [Effects of the Invention]

[0020] The resin-metal composite proposed by the present invention can be adapted to the surface condition of the metal member (X), i.e., a surface condition having surface irregularities, by selecting a resin member (Y) made of a thermoplastic resin composition (A), or a resin member (Y) made of a thermoplastic resin composition (A) containing a fibrous reinforcing filler, and furthermore, by satisfying the following relational expression (1) when the arithmetic mean roughness (Ra) of the surface of the metal member (X) measured in accordance with JIS B 0601:2001, the average fiber diameter (Fd) of the fibrous reinforcing filler, and the ratio of the amount (parts by mass) of the fibrous reinforcing filler to the total amount (parts by mass) of all constituent components in the thermoplastic resin composition (A) are met, thereby increasing the bonding strength with the metal member (X). Ra / (Fd×Wr)≧0.5···(1) Therefore, the resin-metal composite proposed in this invention can have a wide range of applications and can be suitably used in a broad range of applications, from consumer goods to automotive applications. [Brief explanation of the drawing]

[0021] [Figure 1] This is a partial cross-sectional perspective view of a resin-metal composite according to an example of the present invention. [Figure 2] This is a partially enlarged cross-sectional view of Figure 1. [Figure 3] (a) to (e) are all cross-sectional views illustrating examples of joining methods between a metal member (X) and a resin member (Y). [Figure 4] This is a cross-sectional view showing an example of the application of this resin-metal composite as part of the housing of an electrical component for a vehicle. [Figure 5] These are a top view (a) and a cross-sectional view (b) of a resin-metal composite (evaluation sample) formed by joining a metal member (X) and a resin member (Y) as described in the example. [Modes for carrying out the invention]

[0022] Next, the present invention will be described based on examples of embodiments. However, the present invention is not limited to the embodiments described below.

[0023] <<<This resin-metal composite>>> A resin-metal composite according to an example of an embodiment of the present invention (referred to as "this resin-metal composite") comprises a metal member (X) having a surface with surface irregularities on at least one side, and a resin member (Y) made of a thermoplastic resin composition (A) containing a thermoplastic resin and a fibrous reinforcing filler, wherein the surface side of the metal member (X) having surface irregularities and the resin member (Y) are joined together, and is characterized in that it satisfies the following relational expression (1). Ra / (Fd×Wr)≧0.5···(1) (Note that in the above relational expression (1), Ra is the arithmetic mean roughness (μm) of the surface of the metal member (X) measured in accordance with JIS B 0601:2001, Fd is the average fiber diameter (μm) of the fibrous reinforcing filler, and Wr is the amount (parts by mass) of the fibrous reinforcing filler in the thermoplastic resin composition (A) / the total amount (parts by mass) of all constituent components in the thermoplastic resin composition (A).)

[0024] When the above relation (1) is satisfied, the balance between the depth and amount of glass fibers that penetrate into the irregularities of the metal surface becomes good, improving the bonding strength with the metal. From this viewpoint, it is preferable that the value of Ra / (Fd×Wr), i.e., Ra÷Fd÷Wr, be 0.8 or higher, more preferably 1.0 or higher, more preferably 2.0 or higher, even more preferably 5.0 or higher, of which 10 or higher is preferable, of which 20 or higher is preferable, and of which 30 or higher is particularly preferable. While there is no particular upper limit to the value of Ra / (Fd×Wr), from the viewpoint of bonding strength with metal members, it is preferable that it be 70 or less, more preferably 65 or less, more preferably 60 or less, and most preferably 50 or less.

[0025] <<Metal parts (X)>> The metal member (X) is a metal member (X) having a surface with surface irregularities (also referred to as a "rough surface") on all or part of its surface.

[0026] Examples of metals that make up the metal component (X) include various metals such as aluminum, iron, copper, magnesium, tin, nickel, and zinc, as well as alloys containing these metals. Among these, it is preferable to include at least one of aluminum, iron, copper, and magnesium, and alloys containing these metals, and it is more preferable to include aluminum and alloys containing aluminum.

[0027] There are no particular restrictions on the shape of the metal component (X). For example, it is preferably flat, curved, plate-shaped, rod-shaped, cylindrical, block-shaped, sheet-shaped, film-shaped, or manufactured in a specific desired shape. It is not limited to a single flat or curved surface, and may have various shapes such as stepped sections, recesses, and protrusions.

[0028] There are no particular restrictions on the thickness of the metal component (X). However, from a product design standpoint, it is preferable that the thickness be in the range of 0.05 mm to 50 mm, and more preferably 0.10 mm or more or 10 mm or less, and more preferably 0.12 mm or more or 5 mm or less. In particular, for aluminum plates and iron plates, the thickness is preferably 0.10 mm to 10 mm, and more preferably 0.2 mm or more or 5 mm or less. In this case, "thickness" refers to the thickness of the metal component if it is flat, as its thickness is uniform. On the other hand, if the component is not flat, i.e., if its thickness is uneven, it refers to the thickness of the thinnest part of the metal component (X) that is joined to the resin component (Y).

[0029] <Uneven surface> From the viewpoint of bonding strength, the surface of the metal member (X), i.e., the surface that is joined to the resin member (Y), preferably has an arithmetic mean roughness (Ra) of 0.3 μm or more, measured in accordance with JIS B 0601:2001, more preferably 0.5 μm or more, more preferably 5 μm or more, and more preferably 30 μm or more. On the other hand, from the viewpoint of bonding strength after long-term testing, it is preferably 100 μm or less, more preferably 80 μm or less, more preferably 70 μm or less, and more preferably 60 μm or less.

[0030] Furthermore, from a similar viewpoint, the maximum height (Rz) of the surface of the metal member (X), i.e., the surface joined to the resin member (Y), as measured in accordance with JIS B 0601:2001, is preferably 5 μm or more, more preferably 10 μm or more, more preferably 30 μm or more, and more preferably 100 μm or more. On the other hand, from the viewpoint of bonding strength and airtightness, it is preferably 500 μm or less, more preferably 400 μm or less, more preferably 300 μm or less, and more preferably 250 μm or less.

[0031] Thus, as a method for adjusting the arithmetic mean roughness (Ra) of the surface of the metal member (X) to 0.3 μm or more and 100 μm or the maximum height (Rz) to 5 μm or more and 500 μm or less, it is preferable to employ a surface roughening method such as metal surface treatment A or C described later. However, the method is not limited to this.

[0032] The arithmetic mean roughness (Ra) and maximum height (Rz) of a metal component (X) can be calculated by observing the uneven surface of the surface-treated metal component (X) with a 20x objective lens of a hybrid laser microscope (LASERTEC OPTELICS HYBRID) and measuring the surface roughness in accordance with JIS B 0601:2001 using the included analysis software (Lasertec Microscope Solution Software LMeye7).

[0033] In the specific measurements in this example, an FZ image was obtained by using the Fine Peak measurement algorithm to measure the average surface irregularities at the center of a rectangular metal plate measuring 45 mm in length, 12 mm in width, and 1.5 mm in thickness. The measurement range was 4.2 mm in the 45 mm length direction. The cutoff value λc was 0.8000 mm. The same operation was repeated 30 times at arbitrarily different locations, and the average value was calculated. Furthermore, when measuring the uneven surface of the metal component (X) in this resin-metal composite, the same measurement is performed on areas of the metal component (X) surface that are not affected by the bonding. If there are no unbonded areas, the cross-section of this resin-metal composite bonded to the resin component (Y) can be observed and measured using an optical microscope or a scanning electron microscope to obtain values ​​corresponding to the arithmetic mean roughness (Ra) and maximum height (Rz).

[0034] The recesses present on the surface of the metal member (X) do not need to have a uniform opening diameter and depth. Recesses of several different sizes (roughness, height, etc.) may be distributed in combination. Specifically, for example, if the surface has irregularities with an arithmetic mean roughness Ra of 1 μm to 10 μm and a maximum height Rz of 10 μm to 50 μm, a surface in which recesses with an opening diameter and / or depth of 50 μm to 200 μm and recesses with an opening diameter and / or depth of 0.5 μm to 10 μm coexist is preferable from the viewpoint of obtaining high bonding strength and airtightness, rather than having only recesses with a uniform opening diameter and / or depth.

[0035] The metal member (X) and the resin member (Y) may be joined together over the entire surface of the uneven surface of the metal member (X), or they may be joined together over a portion of the uneven surface. Furthermore, it is not necessary for the surface of the metal member (X) to have irregularities at all points where it is in contact with the resin member (Y). In other words, it is sufficient for the surface of the metal member (X) to have irregularities at only a portion of the points where it is joined to the resin member (Y).

[0036] (Surface roughening method) The method for roughening the entire or partial surface of a metal component (X) to create irregularities is not particularly limited, and known methods can be employed. In particular, a chemical treatment method, such as immersion in a chemical solution or coating with a chemical solution, is preferred from the viewpoint that it can be used regardless of the size or shape of the metal component (X). Furthermore, a laser treatment method is also preferred from the viewpoint of achieving mass production and high design quality. Furthermore, the surface roughening method can be carried out using a single method or by combining multiple methods. Combining multiple methods may result in benefits such as optimization of the uneven structure and cost reduction.

[0037] Various chemical treatment methods are known depending on the type of metal, and known methods can be used. When the metal member (X) is aluminum, an aluminum alloy, or cast aluminum, it is preferable to form a film on the metal surface before creating the irregularities, and then remove it to form the irregularities. Furthermore, applying a chemical conversion film after the irregularities are formed is preferable in terms of increasing the bonding strength.

[0038] In particular, as a chemical treatment method for forming the uneven surface, one method can be described as forming a zincate film on the surface of the metal member (X) as needed, and then bringing an etching agent containing peroxodisulfate ions and chloride ions into contact with the surface of the metal member (X).

[0039] The etching agent may be an aqueous solution containing at least peroxodisulfate ions and chloride ions. The etching agent may contain elements such as aluminum, magnesium, silicon, titanium, chromium, manganese, iron, nickel, copper, and zinc derived from the substrate. Furthermore, elements such as zinc may be mixed in as the film formed in the zincate step described later dissolves.

[0040] The etching agent preferably contains peroxodisulfate ions in a proportion of 0.02 mol / L or more and 0.90 mol / L or less, and more preferably contains them in a proportion of 0.10 mol / L or more or 0.50 mol / L or less, and more preferably contains them in a proportion of 0.15 mol / L or more or 0.40 mol / L or less. The etching agent is chloride ions (Cl -It is preferable that the mixture contains ) in a proportion of 0.40 mol / L or more and 2.50 mol / L or less, and more preferably in a proportion of 0.80 mol / L or more or 2.00 mol / L or less, and more preferably in a proportion of 1.20 mol / L or more or 1.70 mol / L or less. As a chloride ion source, one or more suitable chlorine compounds such as lithium chloride, sodium chloride, potassium chloride, calcium chloride, and ammonium chloride can be selected.

[0041] The etching agent may not contain phosphoric acid substantially. "Substantially contained" means that it is below the detection limit.

[0042] The pH of the etching agent is preferably within the range of 6.0 or less, and more preferably within the range of 2.0 to 4.0. The pH of the etching agent can be measured using commercially available pH measuring instruments and electrodes, without any restrictions. Furthermore, by using a pH measuring instrument and electrode with a temperature compensation function, and adjusting the internal solution of the pH electrode and a commercially available pH standard solution to the same temperature as the etching agent, the pH of the etching agent at the temperature in which it is used can also be measured.

[0043] When etching, the etching agent should be heated to a temperature of 10-70°C, and the metal component (X) should be immersed in it.

[0044] Laser processing is a process in which a laser beam is irradiated onto the surface of a metal member (X) to form irregularities on the surface of the metal member (X). One example is laser etching, which processes the metal surface under conditions that involve grooving, melting, and re-solidifying. For example, it can be formed by repeatedly performing laser scanning in a certain scanning direction, followed by laser scanning in the same scanning direction or in a crossing direction. When performing laser processing, it is preferable to irradiate the laser at an angle. Specifically, the laser beam is irradiated onto the metal member surface at an angle of preferably 15 to 85°, more preferably 25 to 75°. With this configuration, the bottom of the recess becomes wider than the opening, and better bonding between the metal member (X) and the thermoplastic resin member (Y) is achieved. The conditions for laser scanning include output power, scan speed, scan frequency, number of scans, hatching width (processing pitch), and patterning shape. By combining these factors, it is possible to form a finely textured surface with desired recesses and protrusions.

[0045] Furthermore, the type of laser used for processing can be appropriately selected from solid-state lasers, fiber lasers, semiconductor lasers, gas lasers, and liquid lasers of various wavelengths. The oscillation mode can also be selected according to the surface irregularities of the metal component, such as continuous waves or pulsed waves. When using continuous waves, it is possible to create more complex irregularities. Furthermore, in addition to the laser treatment described above, other treatment methods such as blasting or chemical treatment may be used in combination.

[0046] When forming a zincate film on the surface of a metal component (X), for example, an aqueous sodium hydroxide solution containing dissolved zinc oxide can be used, and the metal component (X) can be immersed in the solution for about 1.0 second to 5.0 minutes while maintaining a bath temperature of 40.0°C or lower to remove the native oxide film and simultaneously form a zincate film. Alternatively, the formed film may be dissolved with the etching agent or nitric acid, and the process of forming a new film may be repeated one or more times. In addition to the essential components, the treatment solution used in these zincate processes may contain metals such as aluminum, magnesium, silicon, titanium, chromium, manganese, iron, nickel, copper, and zinc derived from the substrate. The pH of the treatment solution used in forming the zincate film is not limited as long as it is within a known range. For example, in the case of a treatment solution exhibiting an alkaline pH, it may be 10.0 or higher, or 13.0 or higher. Preferably, it is within the range of 11.0 to 13.0. To adjust the pH of the zincate solution, sodium hydroxide or potassium hydroxide can be used to raise the pH.

[0047] Furthermore, before treating with an etching agent or forming a zincate film, the surface of the metal component (X) may be cleaned beforehand. For example, degreasing may be performed using a solvent-based, water-based, or emulsion-based degreasing agent. Alternatively, alkaline washing may be performed.

[0048] <Top surface layer> The uneven surface of the metal component (X) may be covered with an oxide film, a chemical conversion film (phosphate film, chromate film, silicate film, lithium chemical conversion film, calcium chemical conversion film, zirconium oxide film, etc.), an anodized film, or other films; or it may have a plating layer, a silane coupling agent treatment layer, a primer layer, a resin layer, or other layers formed on it; or it may have fine particles or the like immobilized on it. Next, we will describe in detail the outermost surface layer of the uneven surface of the metal component (X).

[0049] (Oxide film) The uneven surface of the metal component (X) may be oxidized or not.

[0050] (Chemical conversion coating) The uneven surface of the metal component (X) may be subjected to a chemical conversion treatment and may have a chemical conversion coating. By applying this treatment, the adhesion (bonding properties or adhesive strength) between the metal component (X) and the resin component (Y) can be further improved. Examples of chemical treatment methods include chemical treatment with chromate phosphate, zirconium phosphate treatment, boehmite treatment, zincate treatment, and anodic oxidation treatment. Examples of the above-mentioned anodic oxidation treatments include treatment thin films using phosphoric acid, phosphoric acid-sulfuric acid, phosphoric acid-oxalic acid, or phosphoric acid-chromic acid as the electrolyte. Among these, phosphoric acid anodizing treatment is preferred.

[0051] The thickness of the chemical conversion coating is not particularly limited. For example, 1 nm to 300 nm is preferred, and a thickness of 5 nm or more is even more preferred from the viewpoint of maintaining good processability. Furthermore, when forming a chemical conversion coating by anodizing, the thickness is preferably in the range of 0.05 μm to 2 μm, and more preferably 0.1 μm or more, or 2 μm or less, from the viewpoint of more effectively improving adhesion. The thickness of the chemically treated layer by anodizing can be adjusted to the above range by adjusting the treatment conditions, particularly the energizing conditions and energizing time.

[0052] (Plating layer) The uneven surface of the metal component (X) may be treated to form a plating layer by a plating process such as single-layer plating, multi-layer plating, or alloy plating. Prior to these plating processes, immersion chromic acid treatment or phosphate chromic acid treatment may be performed. The plating method can be either electroplating or electroless plating. For example, if the metal substrate is iron, zinc, tin, nickel, or copper plating is preferred, with zinc plating being more preferred.

[0053] (Silane coupling agent treated layer) In the case of a metal component (X) with an uneven surface, especially if the metal component (X) is made of aluminum or iron, it is preferable to treat it with a silane coupling agent to form a silane coupling agent treated layer. The silane coupling agent is not particularly limited. For example, compounds having methoxy groups, ethoxy groups, silanol groups, etc., can be cited. Preferred silane coupling agents include vinyltrimethoxysilane, chloropropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-(N-styrylmethyl-2-aminoethylamino)propyltrimethoxysilane hydrochloride, and ureidoaminopropylethoxysilane. In particular, the aluminum substrate or iron substrate and the silane coupling agent form Al-O-Si or Fe-O-Si bonds to create a strong bond, and the organic functional groups of the silane coupling agent react with the polyester (a-1) of the thermoplastic resin composition (A) to create a strong bond, achieving an even stronger bond.

[0054] (Primer layer) A primer layer may be provided on the uneven surface of the metal component (X). Examples of materials that can be used for the primer layer include acrylic materials, epoxy materials, urethane materials, and polyamide materials. Examples of commercially available materials used for the primer layer include Aronmelt PPET manufactured by Toagosei Co., Ltd.

[0055] <<Resin component (Y)>> The resin component (Y) is a component made of a thermoplastic resin composition (A). The thermoplastic resin composition (A) preferably comprises a thermoplastic resin and a fibrous reinforcing filler (d), and further optionally comprises an epoxy group-containing compound (b) and further optionally a low molecular weight compound (c).

[0056] The thermoplastic resin content in the thermoplastic resin composition (A) of this embodiment is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 37% by mass or more, and even more preferably 40% by mass or more. Setting the content above the lower limit tends to further improve chemical resistance. Furthermore, the content of the thermoplastic resin is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 72% by mass or less, even more preferably 66% by mass or less, even more preferably 60% by mass or less, and may also be 55% by mass or less, 50% by mass or less, or 47% by mass or less. By keeping it below the above upper limit, the amount of warpage of the molded product tends to be reduced more effectively. The thermoplastic resin composition (A) of this embodiment may contain only one type of thermoplastic resin, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0057] The resin component (Y) is made of a thermoplastic resin composition (A), and may have a structure consisting only of the thermoplastic resin composition (A), or it may have a structure consisting of multiple materials, in which other resin layers different from the thermoplastic resin constituting the thermoplastic resin composition (A) are bonded to the back side of a component or layer made of the thermoplastic resin composition (A).

[0058] The resin component (Y) is not particularly limited in size, shape, thickness, etc., and may be any shape, such as a plate (disc, polygon, etc.), columnar, box-shaped, bowl-shaped, or tray-shaped. One of the features of this resin-metal composite is that the resin component (Y) can be molded into any shape. The resin component (Y) does not need to have a uniform thickness throughout, and may have reinforcing ribs or other arbitrarily shaped parts as needed.

[0059] Examples of thermoplastic resins used in this embodiment include polyester resins (thermoplastic polyester resins); polyamide resins; polycarbonate resins; polystyrene resins; polyolefin resins such as polyethylene resins, polypropylene resins, and cyclic cycloolefin resins; polyacetal resins; polyimide resins; polyetherimide resins; polyurethane resins; polyphenylene ether resins; polyphenylene sulfide resins; polysulfone resins; polymethacrylate resins; and it is more preferable to include at least one of polyolefin resins (preferably polypropylene resins), polycarbonate resins, polyphenylene ether resins, polyester resins, polyphenylene sulfide resins, and polyamide resins; it is even more preferable to include at least one of polycarbonate resins, polyphenylene ether resins, polyester resins, polyphenylene sulfide resins, and polyamide resins; and it is even more preferable to include polyester resins or polyphenylene sulfide resins.

[0060] In this embodiment, an example of a thermoplastic resin is one that includes a polyester resin, wherein 90% or more (preferably 95% or more by mass) of the thermoplastic resin is polyester resin.

[0061] Another example of the thermoplastic resin in this embodiment is that it includes a polyphenylene sulfide resin, wherein 90% or more (preferably 95% or more by mass) of the thermoplastic resin is a polyphenylene ether resin.

[0062] Another example of the thermoplastic resin in this embodiment is that it includes a polycarbonate resin, wherein 90% or more (preferably 95% or more by mass) of the thermoplastic resin is polycarbonate resin.

[0063] Another example of the thermoplastic resin in this embodiment is that it includes a polyphenylene ether resin, wherein 90% or more (preferably 95% or more by mass) of the thermoplastic resin is polyphenylene ether resin.

[0064] Another example of the thermoplastic resin in this embodiment is that it includes a polyolefin resin (preferably a polypyrpropylene resin), and that 90% or more (preferably 95% or more by mass) of the thermoplastic resin is a polyolefin resin (preferably a polypropylene resin).

[0065] Another example of the thermoplastic resin in this embodiment is that it includes a polyamide resin, wherein 90% or more (preferably 95% or more by mass) of the thermoplastic resin is a polyamide resin.

[0066] Examples of polyamide resins in this embodiment include xylylenediamine-based polyamide resins and aliphatic polyamide resins (preferably polyamide 1010), which will be described later. In particular, a preferred example of the thermoplastic resin in this embodiment is that it includes polyphenylene sulfide resin, where 90% or more (preferably 95% or more by mass) of the thermoplastic resin is polyphenylene sulfide resin. Furthermore, a particularly preferred example of the thermoplastic resin is that it includes polyester resin, where 90% or more (preferably 95% or more by mass) of the thermoplastic resin mixture is polyester resin.

[0067] The details of each thermoplastic resin are described below.

[0068] <<Polyester resin>> As the polyester resin, known thermoplastic polyester resins can be used, with polyethylene terephthalate resin and polybutylene terephthalate resin being preferred, and more preferably containing at least polybutylene terephthalate resin.

[0069] The polybutylene terephthalate resin used in the thermoplastic resin composition (A) of this embodiment is a polyester resin having a structure in which terephthalic acid units and 1,4-butanediol units are ester-bonded, and includes polybutylene terephthalate copolymers containing polybutylene terephthalate (homopolymer) as well as other copolymer components other than terephthalic acid units and 1,4-butanediol units, or mixtures of homopolymers and polybutylene terephthalate copolymers. Polybutylene terephthalate resin may contain one or more dicarboxylic acid units other than terephthalic acid.

[0070] Other specific examples of dicarboxylic acids include aromatic dicarboxylic acids such as isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'-carboxyphenyl)methane, anthracenedicarboxylic acid, and 4,4'-diphenyletherdicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 4,4'-dicyclohexyldicarboxylic acid; and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, and dimer acid.

[0071] In this embodiment, the polybutylene terephthalate resin preferably contains terephthalic acid units accounting for 80 mol% or more of the total dicarboxylic acid units, and more preferably 90 mol% or more. The diol unit may include one or more other diol units in addition to 1,4-butanediol.

[0072] Other specific examples of diol units include aliphatic or alicyclic diols with 2 to 20 carbon atoms, and bisphenol derivatives. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethylol, 4,4'-dicyclohexylhydroxymethane, 4,4'-dicyclohexylhydroxypropane, and ethylene oxide addition diols of bisphenol A. In addition to the bifunctional monomers mentioned above, small amounts of trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane can be used to introduce branched structures, and small amounts of monofunctional compounds such as fatty acids can be used to adjust molecular weight.

[0073] In this embodiment, the polybutylene terephthalate resin preferably contains 1,4-butanediol units accounting for 80 mol% or more of the total diol units, and more preferably 90 mol% or more.

[0074] As described above, the polybutylene terephthalate resin is preferably a polybutylene terephthalate homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol. Alternatively, it may be a polybutylene terephthalate copolymer containing one or more dicarboxylic acids other than terephthalic acid as the carboxylic acid unit and / or one or more diols other than 1,4-butanediol as the diol unit. When the polybutylene terephthalate resin is a polybutylene terephthalate resin modified by copolymerization, specific preferred copolymers include polyester ether resins copolymerized with polyalkylene glycols, particularly polytetramethylene glycol, dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins. Among these, it is preferable to use a polyester ether resin copolymerized with polytetramethylene glycol. These copolymers refer to those with a copolymerization amount of 1 mol% or more and less than 50 mol% of the total segments of the polybutylene terephthalate resin. In particular, the copolymerization amount is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and even more preferably 5 to 20 mol%. Such copolymerization ratios tend to improve fluidity, toughness, and tracking resistance, and are therefore preferable.

[0075] The amount of terminal carboxyl groups in polybutylene terephthalate resin can be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. Keeping it below the above upper limit tends to improve alkali resistance and hydrolysis resistance. There is no specific lower limit for the amount of terminal carboxyl groups, but considering the productivity of polybutylene terephthalate resin production, it is usually 10 eq / ton or more.

[0076] The amount of terminal carboxyl groups in polybutylene terephthalate resin is measured by dissolving 0.5 g of polybutylene terephthalate resin in 25 mL of benzyl alcohol and titrating it with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide. The amount of terminal carboxyl groups can be adjusted by any conventionally known method, such as adjusting polymerization conditions like the raw material ratio, polymerization temperature, and reduced pressure method during polymerization, or by reacting with a chelating agent.

[0077] The intrinsic viscosity of the polybutylene terephthalate resin is preferably 0.5 to 2 dL / g. From the viewpoint of moldability and mechanical properties, an intrinsic viscosity in the range of 0.6 to 1.5 dL / g is more preferable. Setting the intrinsic viscosity to 0.5 dL / g or higher tends to further improve the mechanical strength of the resulting resin composition. Conversely, setting it to 2 dL / g or lower tends to further improve the fluidity of the resin composition and thus improve moldability. The intrinsic viscosity of polybutylene terephthalate resin is measured at 30°C in a 1:1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

[0078] Polybutylene terephthalate resin can be produced by melt polymerization of a dicarboxylic acid component mainly composed of terephthalic acid or ester derivatives thereof, and a diol component mainly composed of 1,4-butanediol, in a batch or continuous manner. Furthermore, after producing a low molecular weight polybutylene terephthalate resin by melt polymerization, the degree of polymerization (or molecular weight) can be increased to a desired value by further solid-phase polymerization under a nitrogen atmosphere or reduced pressure. The polybutylene terephthalate resin is preferably obtained by a manufacturing method in which a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of 1,4-butanediol are continuously melt-polycondensed.

[0079] The catalyst used in carrying out the esterification reaction may be one of the conventionally known ones, such as titanium compounds, tin compounds, magnesium compounds, and calcium compounds. Among these, titanium compounds are particularly preferred. Specific examples of titanium compounds as esterification catalysts include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

[0080] In addition to the above, the description in paragraphs 0013 to 0016 of Japanese Patent Publication No. 2010-174223 can be given to the polyester resin, and its contents are incorporated herein by reference.

[0081] In the thermoplastic resin composition (A) of this embodiment, the polybutylene terephthalate resin content is preferably 20% by mass or more, more preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 37% by mass or more, and even more preferably 40% by mass or more. Setting it above the lower limit tends to further improve chemical resistance. Furthermore, when the thermoplastic resin composition (A) contains polybutylene terephthalate resin, the polybutylene terephthalate resin content is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 72% by mass or less, even more preferably 66% by mass or less, even more preferably 60% by mass or less, and may also be 55% by mass or less, 50% by mass or less, or 47% by mass or less. Setting it below the upper limit tends to more effectively reduce the amount of warpage of the molded product.

[0082] The thermoplastic resin composition (A) of this embodiment may contain only one type of polybutylene terephthalate resin, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0083] <<Polycarbonate resin>> Polycarbonate resin is a branched homopolymer or copolymer obtained by reacting a dihydroxy compound, or a small amount thereof, with a polyhydroxy compound with phosgene or a diester carbonate. The method for producing polycarbonate resin is not particularly limited, and conventionally known methods such as the phosgene method (interfacial polymerization) or the melting method (transesterification) can be used.

[0084] As the raw material dihydroxy compound, aromatic dihydroxy compounds are preferred, including 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, and others, with bisphenol A being preferred. In addition, compounds in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compounds can also be used.

[0085] Among the polycarbonate resins mentioned above, aromatic polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane, or aromatic polycarbonate copolymers derived from 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy compounds are preferred. Alternatively, copolymers mainly composed of aromatic polycarbonate resins, such as copolymers with polymers or oligomers having a siloxane structure, may also be used. Furthermore, two or more of the above-mentioned polycarbonate resins may be mixed and used.

[0086] To adjust the molecular weight of polycarbonate resin, monovalent aromatic hydroxy compounds can be used, such as m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, and p-long-chain alkyl-substituted phenols.

[0087] The viscosity-average molecular weight (Mv) of the polycarbonate resin is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 13,000 or more. Using a resin with a viscosity-average molecular weight of 5,000 or more tends to improve the mechanical strength of the resulting resin composition. Furthermore, the viscosity-average molecular weight (Mv) of the polycarbonate resin is preferably 6,000 or less, more preferably 40,000 or less, and even more preferably 30,000 or less. Using a resin with a viscosity-average molecular weight of 60,000 or less tends to improve the fluidity of the resin composition and improve its moldability.

[0088] In this embodiment, the viscosity-average molecular weight (Mv) of the polycarbonate resin is calculated using an Ubbelohde viscometer to determine the intrinsic viscosity ([η]) of the methylene chloride solution of the polycarbonate resin at 20°C, and the value is derived from Schnell's viscosity formula. [η] = 1.23 × 10 -4 Mv 0.83

[0089] The method for producing the polycarbonate resin is not particularly limited, and polycarbonate resin produced by either the phosgene method (interfacial polymerization method) or the melting method (transesterification method) can be used. Furthermore, polycarbonate resin produced by the melting method and then subjected to post-treatment to adjust the amount of terminal OH groups is also preferred.

[0090] <<Polystyrene resin>> Examples of polystyrene resins include homopolymers of styrene monomers and copolymers of styrene monomers with other copolymerizable monomers.

[0091] More specifically, polystyrene-based resins include polystyrene resin, acrylonitrile-styrene copolymer (AS resin), high-impact polystyrene-based resin (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin), styrene-IPN type rubber copolymer, and other resins.

[0092] When a polystyrene resin contains rubber components, the content of rubber components in the polystyrene resin is preferably 3 to 70% by mass, more preferably 5 to 50% by mass, and even more preferably 7 to 30% by mass. A rubber component content of 3% by mass or more tends to improve impact resistance, while a content of 50% by mass or less tends to improve flame retardancy, which is preferable. Furthermore, the average particle size of the rubber components is preferably 0.05 to 10 μm, more preferably 0.1 to 6 μm, and even more preferably 0.2 to 3 μm. An average particle size of 0.05 μm or more tends to improve impact resistance, while an average particle size of 10 μm or less tends to improve appearance, which is preferable.

[0093] The weight-average molecular weight of polystyrene resins is typically 50,000 or more, preferably 100,000 or more, more preferably 150,000 or more, and also typically 500,000 or less, preferably 400,000 or less, and more preferably 300,000 or less. The number-average molecular weight is typically 10,000 or more, preferably 30,000 or more, more preferably 50,000 or more, and also preferably 500,000 or less, and more preferably 300,000 or less.

[0094] The melt flow rate (MFR) of polystyrene resins, measured in accordance with JIS K7210 (temperature 200°C, load 5 kgf), is preferably 0.1 to 30 g / 10 min, and more preferably 0.5 to 25 g / 10 min. When the MFR is 0.1 g / 10 min or higher, fluidity tends to improve, and when it is 30 g / 10 min or lower, impact resistance tends to improve. Known methods for producing such polystyrene resins include emulsion polymerization, solution polymerization, suspension polymerization, and bulk polymerization.

[0095] <<Polyphenylene ether resin>> In this embodiment, a known polyphenylene ether resin can be used. For example, a polymer having a structural unit represented by the following formula in the main chain (preferably, a polymer in which the structural unit represented by the following formula occupies 90 mol% or more of all the structural units excluding the terminal groups) is exemplified. The polyphenylene ether resin may be either a homopolymer or a copolymer.

[0096] TIFF0007868506000001.tif79115

[0097] In the formula, two Rs a each independently represent a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, an aminoalkyl group, a halogenated alkyl group, a hydrocarbon oxy group, or a halogenated hydrocarbon oxy group. Two Rs b each independently represent a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, a halogenated alkyl group, a hydrocarbon oxy group, or a halogenated hydrocarbon oxy group. However, the two Rs a will not both be hydrogen atoms.

[0098] R a and R b are each independently preferably a hydrogen atom, a primary or secondary alkyl group, or an aryl group. Preferred examples of the primary alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-amyl group, an isoamyl group, a 2-methylbutyl group, a 2,3-dimethylbutyl group, a 2-, 3- or 4-methylpentyl group, or a heptyl group. Preferred examples of the secondary alkyl group include, for example, an isopropyl group, a sec-butyl group, or a 1-ethylpropyl group. In particular, R a is preferably a primary or secondary alkyl group having 1 to 4 carbon atoms or a phenyl group. R b is preferably a hydrogen atom.

[0099] Suitable homopolymers of polyphenylene ether resins include, for example, polymers of 2,6-dialkylphenylene ethers such as poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene ether), poly(2,6-dipropyl-1,4-phenylene ether), poly(2-ethyl-6-methyl-1,4-phenylene ether), and poly(2-methyl-6-propyl-1,4-phenylene ether). As copolymers, 2,6-dialkylphenol / 2,3,6-trialkylphenol copolymers such as 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol / 2,3,6-triethylphenol copolymer, 2,6-diethylphenol / 2,3,6-trimethylphenol copolymer, and 2,6-dipropylphenol / 2,3,6-trimethylphenol copolymer are preferred. Graft copolymers are obtained by graft polymerization of styrene onto poly(2,6-dimethyl-1,4-phenylene ether). In the 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer embodiment, polyphenylene ether resin is particularly preferred, especially poly(2,6-dimethyl-1,4-phenylene) ether and 2,6-dimethylphenol / 2,3,6-trimethylphenol random copolymer. Furthermore, polyphenylene ether resins with specified terminal group numbers and copper content, as described in Japanese Patent Publication No. 2005-344065, can also be suitably used.

[0100] The polyphenylene ether resin is preferably one with an intrinsic viscosity of 0.2 to 0.8 dL / g, and more preferably 0.3 to 0.6 dL / g, measured in chloroform at 30°C. A viscosity of 0.2 dL / g or higher tends to improve the mechanical strength of the resin composition, while a viscosity of 0.8 dL / g or lower tends to improve fluidity and facilitate molding. Alternatively, two or more polyphenylene ether resins with different intrinsic viscosities may be used in combination to achieve this viscosity range.

[0101] The method for producing the polyphenylene ether resin used in this embodiment is not particularly limited, and a known method can be employed, for example, by oxidative polymerization of a monomer such as 2,6-dimethylphenol in the presence of an amine copper catalyst. In this case, the intrinsic viscosity can be controlled to a desired range by selecting the reaction conditions. Control of the intrinsic viscosity can be achieved by selecting conditions such as polymerization temperature, polymerization time, and catalyst amount.

[0102] <<Polyolefin resin>> Examples of polyolefin resins include polyethylene, polypropylene, polybutene-1, and poly-4-methylpentene, as well as copolymers thereof. Examples of polyethylene include low-density polyethylene and high-density polyethylene. Examples of polypropylene include crystalline or amorphous polypropylene. Examples of the copolymers include random, block, or graft copolymers of ethylene-propylene, copolymers of α-olefin and ethylene or propylene, ethylene-vinyl acetate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, and ethylene-acrylic acid copolymers.

[0103] Among these, crystalline or amorphous polypropylene, and random, block, or graft copolymers of ethylene-propylene are preferred, with propylene-ethylene block copolymers being more preferred. Furthermore, polypropylene resin is preferred from the viewpoint of being inexpensive and having a low specific gravity, which allows for lighter molded products. The melt flow rate (MFR) of the polyolefin resin is preferably 0.1 to 5.0 g / 10 min.

[0104] <<Polyamide resin>> Polyamide resins are polymers whose constituent units are acid amides obtained by ring-opening polymerization of lactams, polycondensation of aminocarboxylic acids, and polycondensation of diamines and dibasic acids. Specifically, examples include polyamides 6, 11, 12, 46, 66, 610, 612, 6I, 6 / 66, 6T / 6I, 6 / 6T, 66 / 6T, 66 / 6T / 6I, 1010, xylylenediamine-based polyamide resins (details to be described later), polytrimethylhexamethylene terephthalamide, polybis(4-aminocyclohexyl)methanedodecamamide, polybis(3-methyl-4-aminocyclohexyl)methanedodecamamide, and polyundemethylenehexahydroterephthalamide. Note that "I" indicates the isophthalic acid component and "T" indicates the terephthalic acid component. Furthermore, as a polyamide resin, reference can be given to the description in paragraphs 0011 to 0013 of Japanese Patent Publication No. 2011-132550, which is incorporated herein by reference.

[0105] The polyamide resin used in this embodiment is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, and a xylylenediamine-based polyamide resin is preferred in which 50 mol% or more of the diamine-derived structural units are derived from xylylenediamine. More preferably, 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more of the diamine-derived structural units of the xylylenediamine-based polyamide resin are derived from at least one of meta-xylylenediamine and para-xylylenediamine. More preferably, 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more, the dicarboxylic acid-derived structural units of the xylylenediamine-based polyamide resin are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms. α,ω-linear aliphatic dibasic acids having 4 to 20 carbon atoms can be suitably used, such as adipic acid, sebacic acid, suberic acid, dodecanediic acid, and eicodionic acid, with adipic acid and sebacic acid being more preferred.

[0106] Diamines other than meta-xylylenediamine and para-xylylenediamine that can be used as raw material diamine components for xylylenediamine-based polyamide resins include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine, as well as 1,3-bis( Examples include alicyclic diamines such as aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane, as well as aromatic ring-containing diamines such as bis(4-aminophenyl) ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. One or more of these can be used in combination.

[0107] Examples of dicarboxylic acid components other than the above-mentioned α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms include phthalate compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. One or more of these can be used in combination.

[0108] <<Polyphenylene sulfide resin>> In this embodiment, known polyphenylene sulfide resins can be used, for example, polymers having repeating units shown in the following structural formula are exemplified. From the viewpoint of heat resistance, polymers containing 70 mol% or more, and more preferably 90 mol% or more, of polymers containing repeating units shown in the following structural formula are preferred. The polyphenylene sulfide resin (PPS resin) has the above chemical structure and preferably has a melt flow rate of 1000 g / 10 min or more, and more preferably 3000 g / 10 min or more, at 315°C and under a 5000 g load as defined in ASTM D1238-86.

[0109] TIFF0007868506000002.tif79115

[0110] In this embodiment, the thermoplastic resin composition (A) is particularly preferably a polyester resin composition containing polyester (a-1) and a thermoplastic resin (a-2) compatible with polyester (a-1) as the main component resin. The term "main component resin" refers to the resin or group of resins that constitute the thermoplastic resin composition (A) and have the largest mass percentage among the resins that make up the composition. This includes cases where polyester (a-1) and thermoplastic resin (a-2) account for 50% by mass or more of the resins that make up the thermoplastic resin composition (A), with 75% by mass or more of those, and 90% by mass or more (including 100% by mass) among those. However, there are also cases where polyester (a-1) and thermoplastic resin (a-2) each consist of two or more types of polyester (resin group).

[0111] In the thermoplastic resin composition (A), the ratio of polyester (a-1) to thermoplastic resin (a-2) is preferably a mass ratio of (a-1):(a-2)=20:80 to 80:20, from the viewpoint of moldability and bonding strength with metal members. Furthermore, if polyester (a-1) is included in a ratio of (a-1):(a-2) = 50:50 or higher, it is preferable from the viewpoint of improving bonding strength and the basic physical properties of the resin, and if thermoplastic resin (a-2) is included in a ratio of (a-1):(a-2) = 50:50 to 80:20, it is preferable from the viewpoint of improving bonding strength. From this viewpoint, (a-1):(a-2) = 50:50 to 80:20 is preferable, of which 55:45 to 80:20 is preferable, and of which 60:40 to 80:20 is even more preferable.

[0112] The intrinsic viscosity of the thermoplastic resin composition (A) is preferably 0.30 to 2.00 dl / g from the viewpoint of moldability, more preferably 0.40 dl / g or more, and more preferably 0.60 dl / g or more, while more preferably 1.80 dl / g or less, and more preferably 1.50 dl / g or less.

[0113] In this invention, the intrinsic viscosity is the value measured at 30°C in a 1:1 (mass ratio) mixed solvent of tetrachloroethane and phenol. The intrinsic viscosity of thermoplastic resin composition (A) can be adjusted by changing the molecular weight of polyester (a-1), but is not limited to this.

[0114] <Polyester (a-1)> The polyester (a-1) as the main component resin is preferably polybutylene terephthalate (also referred to as "homo-PBT"), a copolymer of polybutylene terephthalate (also referred to as "polymer PBT"), or a mixture thereof.

[0115] The intrinsic viscosity of polyester (a-1) is preferably 0.30 to 2.00 dl / g from the viewpoint of moldability, more preferably 0.40 dl / g or more, and more preferably 0.60 dl / g or more, while more preferably 1.80 dl / g or less, and more preferably 1.50 dl / g or less. The intrinsic viscosity of polyester (a-1) can be adjusted by changing the molecular weight of polyester (a-1), but is not limited to this.

[0116] (Homo PBT) Homo-PBT is a polymer having a structure in which terephthalic acid units and 1,4-butanediol units are ester-bonded, and is a polymer composed of terephthalic acid units and 1,4-butanediol units.

[0117] The amount of terminal carboxyl groups in homo-PBT is preferably 60 eq / ton or less, more preferably 50 eq / ton or less, and even more preferably 30 eq / ton or less. The amount of terminal carboxyl groups in polybutylene terephthalate homopolymer can be determined by dissolving 0.5 g of resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / l benzyl alcohol solution of sodium hydroxide. The amount of terminal carboxyl groups can be adjusted by any conventionally known method, such as adjusting polymerization conditions like the raw material ratio, polymerization temperature, and reduced pressure method during polymerization, or by reacting with a chelating agent.

[0118] The number-average molecular weight of homoPBT is preferably 7,000 or more, more preferably 8,000 or more, and more preferably 9,000 or more. On the other hand, it is preferably 20,000 or less, more preferably 19,000 or less, and more preferably 17,000 or less.

[0119] The intrinsic viscosity of homo PBT is preferably 0.30 to 2.00 dl / g. If the intrinsic viscosity is 0.30 dl / g or higher, the mechanical strength of the welded body will not become too low, and if it is 2.00 dl / g or lower, it is possible to prevent a decrease in fluidity, which can lead to deterioration of moldability and a decrease in joint strength. From this viewpoint, the intrinsic viscosity of homo PBT is preferably 0.30 to 2.00 dl / g, more preferably 0.40 dl / g or more, and more preferably 0.60 dl / g or more, while it is even more preferably 1.80 dl / g or less, and more preferably 1.50 dl / g or less.

[0120] (Copolymerized PBT) Copolymerized PBT is a polybutylene terephthalate copolymer containing copolymer components other than terephthalic acid units and 1,4-butanediol units.

[0121] Other specific examples of dicarboxylic acid units besides terephthalic acid include, for example, aromatic dicarboxylic acids such as isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'-carboxyphenyl)methane, anthracenedicarboxylic acid, and 4,4'-diphenyletherdicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 4,4'-dicyclohexyldicarboxylic acid; and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, and dimer acid.

[0122] Other diol units besides 1,4-butanediol include aliphatic or alicyclic diols with 2 to 20 carbon atoms, and bisphenol derivatives. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane, 4,4'-dicyclohexylhydroxypropane, and ethylene oxide addition diols of bisphenol A.

[0123] From the viewpoint of mechanical properties and heat resistance, copolymerized PBT preferably has a terephthalic acid content of 70 mol% or more in the dicarboxylic acid units, and more preferably 90 mol% or more. Furthermore, it is preferable that the proportion of 1,4-butanediol in the diol unit be 70 mol% or more, and more preferably 90 mol% or more.

[0124] In addition to the difunctional monomers mentioned above, copolymerized PBT can also incorporate small amounts of polyfunctional monomers such as trifunctional acids (e.g., trifunctional acids like tricarbaryl acid, trimellicin acid, trimellitic acid, etc.) or tetrafunctional acids (e.g., pyromellitic acid) that have ester-forming ability, or trifunctional or tetrafunctional alcohols (e.g., glycerin, trimethylolpropane, pentaerythritol) that have ester-forming ability, or monofunctional compounds such as fatty acids to adjust molecular weight, in order to introduce branched structures.

[0125] Copolymerized PBT can be modified by copolymerizing components. For example, the copolymer components include polybutylene terephthalate resin copolymerized with polyalkylene glycols (particularly polytetramethylene glycol (PTMG)), dimer acid copolymerized polybutylene terephthalate resin, and especially isophthalic acid copolymerized polybutylene terephthalate resin.

[0126] In copolymerized PBT obtained by copolymerizing polytetramethylene glycol (PTMG), the proportion of tetramethylene glycol component in the copolymer is preferably 3 to 40% by mass, more preferably 5% or more by mass or 30% or less by mass, and more preferably 10% or more by mass or 25% or less by mass. Such copolymerization ratios tend to result in an excellent balance between bonding strength and heat resistance, which is preferable. On the other hand, in the case of copolymerized PBT obtained by copolymerizing dimer acid, the proportion of dimer acid components to the total carboxylic acid components is preferably 0.5 to 30 mol% as carboxylic acid groups, and more preferably 1 mol% or more or 20 mol% or less, and more preferably 3 mol% or more or 15 mol% or less. Such copolymerization ratios tend to result in an excellent balance of bonding strength, long-term heat resistance, and toughness, which is preferable. Furthermore, in the case of copolymerized PBT obtained by copolymerizing isophthalic acid, the proportion of isophthalic acid components to the total carboxylic acid components is preferably 1 to 30 mol% as carboxylic acid groups, more preferably 2 mol% or more or 20 mol% or less, and more preferably 3 mol% or more or 15 mol% or less. Such copolymerization ratios tend to result in an excellent balance of bonding strength, heat resistance, injection moldability, and toughness, which is preferable. As for copolymerized PBT, from the viewpoint of moldability, copolymerized PBT obtained by copolymerizing polytetramethylene glycol or copolymerized PBT obtained by copolymerizing isophthalic acid is particularly preferred.

[0127] The number-average molecular weight of copolymerized PBT is preferably 5000 or more, more preferably 6000 or more, and more preferably 8000 or more. On the other hand, it is preferably 20000 or less, more preferably 19000 or less, and more preferably 17000 or less.

[0128] The copolymerized PBT preferably has an intrinsic viscosity of 0.30 to 2.00 dl / g. If the intrinsic viscosity is 0.30 dl / g or higher, the mechanical strength of the welded body will not become too low, and if it is 2.00 dl / g or lower, it is possible to prevent a decrease in fluidity, which can lead to deterioration of moldability and a decrease in joint strength. From this viewpoint, the intrinsic viscosity of copolymerized PBT is preferably 0.30 to 2.00 dl / g, more preferably 0.40 dl / g or more, and more preferably 0.60 dl / g or more, while it is even more preferably 1.80 dl / g or less, and more preferably 1.50 dl / g or less.

[0129] The amount of terminal carboxyl groups in copolymerized PBT is preferably 60 eq / ton or less. If the amount of terminal carboxyl groups is 60 eq / ton or less, gas generation can be suppressed during melt molding of the resin composition. From this viewpoint, the amount of terminal carboxyl groups in copolymerized PBT is preferably 60 eq / ton or less, more preferably 50 eq / ton or less, and even more preferably 30 eq / ton or less. On the other hand, there is no specific lower limit for the amount of terminal carboxyl groups. It is usually 5 eq / ton or more. The amount of terminal carboxyl groups in copolymerized PBT can be determined by dissolving 0.5 g of resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / l benzyl alcohol solution of sodium hydroxide. The amount of terminal carboxyl groups can be adjusted by any conventionally known method, such as adjusting polymerization conditions like the raw material ratio, polymerization temperature, and reduced pressure method during polymerization, or by reacting with a chelating agent.

[0130] (Homo PBT + Copolymer PBT) Polyester (a-1) may be a mixed resin of homo-PBT and copolymer PBT. In this case, it is preferable that the amount of copolymer components (monomers) in the copolymer PBT resin is 0.1 mol% or more and 30 mol% or less relative to the total monomers, and more preferably 1 mol% or more or 25 mol% or less, and more preferably 5 mol% or more or 20 mol% or less. In terms of mass ratio, the mixing ratio of homo-PBT / polymer is preferably 99 / 1 to 1 / 99 (mass ratio), and more preferably in the range of 95 / 5 to 5 / 95 (mass ratio), and even more preferably in the range of 90 / 10 to 10 / 90 (mass ratio).

[0131] <Thermoplastic resin (a-2)> The thermoplastic resin (a-2) can be any thermoplastic resin that is compatible with the polyester (a-1) described above.

[0132] From the standpoint of compatibility between the two, it is preferable that the difference in solubility parameters (also referred to as "SP values") between the thermoplastic resin (a-2) and polyester (a-1) is 2 or less, preferably 1 or less, and most preferably 0.5 or less. Incidentally, the solubility parameter of polybutylene terephthalate resin is 12.1 (cal / cm³). 3 ), the SP value of polyethylene terephthalate resin is 11.5 (cal / cm³). 3 ), the SP value of CHDM-modified polyethylene terephthalate resin (CHDM ratio in diol component = 30 mol%) is 11.5 (cal / cm³). 3 ) and the SP value of polycarbonate resin is 11.6 (cal / cm²). 3 ) The SP value in this invention is a value that can be calculated according to the method of FEDORS (R. FEDORS, POLYMER ENGINEERING AND SCIENCE, FEBRUARY, 1974, Vol 14, No. 2).

[0133] Examples of thermoplastic resins (a-2) include polyesters other than homo-PBT and copolymer PBT, polycarbonates, and polystyrene-based resins.

[0134] Other polyesters besides homo-PBT and copolymer PBT include polytrimethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polyethylene terephthalate. Among these, polyethylene terephthalate is preferred from the viewpoint of improving bonding strength.

[0135] Examples of polycarbonate and polystyrene resins include the aforementioned polycarbonate and polystyrene resins.

[0136] <Epoxy group-containing compound (b)> The thermoplastic resin composition (A) of the present invention may optionally contain an epoxy group-containing compound (b). The epoxy group-containing compound (b) does not necessarily contribute to the initial bond strength, but improves the desired durability by measuring the bond strength after durability testing. The inclusion of epoxy group-containing compound (b) significantly improves durability. This durability does not decrease even when low-molecular-weight compound (c) is included. It can be inferred that the hydrolysis resistance of the resin component (Y) is enhanced by the reaction between the terminal functional groups (carboxyl groups) of homo-PBT and / or copolymerized PBT and the epoxy groups of the epoxy group-containing compound (b).

[0137] Examples of epoxy group-containing compounds (b) include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, resorcinol type epoxy compounds, novolac type epoxy compounds, alicyclic compound type diepoxy compounds, glycidyl ethers, epoxidized polybutadiene, and more specifically, alicyclic compound type epoxy compounds such as bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, resorcinol type epoxy compounds, novolac type epoxy compounds, vinylcyclohexene dioxide, and dicyclopentadiene oxide.

[0138] In particular, 2,2-bis(4-hydroxyphenyl)-propane type epoxy compounds (also referred to as "bisphenol A type epoxy compounds") and novolac type epoxy compounds are preferred in terms of compatibility with homo-PBT and / or copolymerized PBT.

[0139] In particular, the epoxy equivalent (mass (g) per mole of epoxy groups contained in the epoxy compound) of the bisphenol A type epoxy compound and the novolac type epoxy compound is preferably 50 to 1000 g / eq., more preferably 70 g / eq. or more, and more preferably 100 g / eq. or more, while more preferably 900 g / eq. or less, and more preferably 800 g / eq. or less.

[0140] Furthermore, the number-average molecular weight of the bisphenol A type epoxy compound and the novolac type epoxy compound is preferably 100 to 2000 in terms of fluidity, more preferably 150 or more, and more preferably 200 or more, while more preferably 1800 or less, and more preferably 1600 or less.

[0141] The epoxy group-containing compound (b) is preferably included in a ratio of 0.001 to 35 parts by mass per 100 parts by mass of polyester (a-1) from the viewpoint of improving bonding strength and fluidity, and more preferably in a ratio of 0.01 parts by mass or more, of which 0.1 parts by mass or more, and of which 0.3 parts by mass or more, while it is even more preferably included in a ratio of 25 parts by mass or less, of which 15 parts by mass or less, of which 10 parts by mass or less, and of which 6 parts by mass or less.

[0142] Furthermore, from the viewpoint of improving bonding strength, the epoxy group-containing compound (b) is preferably contained in a proportion of 0.1 to 10 equivalents of epoxy groups relative to the amount of terminal carboxyl groups in the polyester (a-1), which is homo-PBT and / or copolymer PBT. More preferably, it is contained in a proportion of 0.15 equivalents or more, and of which, 0.2 equivalents or more, while even more preferably, it is contained in a proportion of 8.0 equivalents or less, of which, 7.0 equivalents or less, and of which, 6.0 equivalents or less.

[0143] <Low molecular compound (c)> If the thermoplastic resin composition (A) of the present invention further contains a low molecular weight compound (c) having a number average molecular weight of less than 6000, the bonding strength of the resin-metal composite can be further increased.

[0144] The number-average molecular weight of the low molecular weight compound (c) is preferably less than 6000, more preferably 50 or more, and more preferably 100 or more. On the other hand, it is more preferably 5000 or less, more preferably 4500 or less, and more preferably 4200 or less.

[0145] Examples of low molecular weight compounds (c) include one or more low molecular weight compounds selected from polyolefin compounds, aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds, and silicone compounds.

[0146] Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax. Modified polyolefin compounds may also be used, in which hydroxyl groups, carboxyl groups, anhydride groups, epoxy groups, etc., are introduced into the side chains.

[0147] Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent, or trivalent carboxylic acids. Here, aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and more preferably aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetrariacontanoic acid, montanic acid, adipic acid, and azelaic acid.

[0148] For example, the same aliphatic carboxylic acid as described above can be used as the aliphatic carboxylic acid in the ester of the aliphatic carboxylic acid and the alcohol. On the other hand, examples of alcohols include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have substituents such as fluorine atoms or aryl groups. Among these, monohydric or polyhydric saturated alcohols with 30 or fewer carbon atoms are preferred, and aliphatic saturated monohydric alcohols or aliphatic saturated polyhydric alcohols with 30 or fewer carbon atoms are more preferred. Here, "aliphatic" also includes alicyclic compounds. Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, and dipentaerythritol.

[0149] Furthermore, the above-mentioned ester of aliphatic carboxylic acid and alcohol may contain aliphatic carboxylic acid and / or alcohol as impurities. Also, the above-mentioned ester may be a pure substance or a mixture of multiple compounds. Moreover, the aliphatic carboxylic acid and alcohol that combine to form a single ester may be used individually, or two or more may be used in any combination and ratio.

[0150] Specific examples of esters of aliphatic carboxylic acids and alcohols include, for example, montanate wax, beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.

[0151] Examples of the aliphatic hydrocarbon compounds include liquid paraffin, paraffin wax, microcrystalline wax, polyolefin waxes such as polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. Here, aliphatic hydrocarbons include alicyclic hydrocarbons. Furthermore, these hydrocarbons may be partially oxidized. The aliphatic hydrocarbon compound may be a single substance or a mixture of substances with varying constituent components and molecular weights; it can be used as long as the main component falls within the above range.

[0152] Examples of the aforementioned silicone-based compounds include modified silicone oils, such as silicone oils in which organic groups are introduced into the side chains of polysiloxane, and silicone oils in which organic groups are introduced into both ends and / or one end of polysiloxane. Examples of the organic groups introduced include epoxy groups, amino groups, carboxyl groups, carbinol groups, methacrylic groups, mercapto groups, and phenol groups, with epoxy groups being preferred. As the modified silicone oil, a silicone oil in which epoxy groups are introduced into the side chains of polysiloxane is particularly preferred.

[0153] As for low molecular weight compounds, polyolefin waxes are particularly preferred from the viewpoint of low gas emissions and suppression of generated gases. Any conventionally known polyolefin wax can be used, for example, a (co)polymer (meaning polymerization or copolymerization; the same applies hereinafter) containing one or more olefins in any proportion, preferably having 2 to 30 carbon atoms, more preferably 2 to 12, and even more preferably 2 to 10 carbon atoms.

[0154] Examples of olefins having 2 to 30 carbon atoms include ethylene, propylene, α-olefins having 4 to 30 carbon atoms (preferably 4 to 12, more preferably 4 to 10), and dienes having 4 to 30 carbon atoms (preferably 4 to 18, more preferably 4 to 8). Examples of α-olefins include 1-butene, 4-methyl-1-pentene, 1-pentene, 1-octene, 1-decene, and 1-dodecene. Examples of dienes include butadiene, isoprene, cyclopentadiene, and 11-dodecadiene.

[0155] As a polyolefin wax, polyethylene wax is preferred due to its low gas emissions, reduced gas generation, improved bonding strength, and heat resistance. The method for producing polyethylene wax is arbitrary and can be, for example, by polymerization of ethylene or thermal decomposition of polyethylene.

[0156] Among the low molecular weight compounds, those with an acid value of 0.01 to 40 mgKOH / g are preferred because they significantly improve bonding strength and have low volatile content. More preferably, the acid value is 0.01 to 35 mgKOH / g, even more preferably 0.5 to 32 mgKOH / g, and particularly preferably 0.5 to 20 mgKOH / g. As long as the acid value is in the range of 0.01 to 40 mgKOH / g, it is acceptable to use a combination of compounds with an acid value of less than 0.01 mgKOH / g and those with an acid value of more than 40 mgKOH / g, as long as the overall acid value of the multiple types of low-molecular-weight compounds is within the range of 0.01 to 40 mgKOH / g.

[0157] As low molecular weight compounds with an acid value of 0.01 to 40 mg KOH / g, preferred are esters of aliphatic carboxylic acids and alcohols with an acid value of 0.01 to 40 mg KOH / g, or modified polyolefin waxes obtained by imparting functional groups with affinity to polyester resins, such as carboxyl groups (carboxylic acid (anhydride) groups, i.e., carboxylic acid groups and / or carboxylic acid anhydride groups; the same applies hereinafter), haloformyl groups, ester groups, carboxylic acid metal bases, hydroxyl groups, alkosyl groups, epoxy groups, amino groups, amide groups, etc., to the above-mentioned aliphatic hydrocarbon compounds, preferably polyolefin waxes.

[0158] Examples of carboxyl groups used to modify this polyolefin wax include low molecular weight compounds containing carboxylic acid groups such as maleic acid, maleic anhydride, acrylic acid, and methacrylic acid; low molecular weight compounds containing sulfonic acid and other sulfo groups; and low molecular weight compounds containing phosphonic acid and other phospho groups. Among these, low molecular weight compounds containing carboxylic acid groups are preferred, with maleic acid, maleic anhydride, acrylic acid, and methacrylic acid being particularly preferred. These carboxylic acids may be used individually or in combination of two or more in any proportion. The amount of acid added to the modified polyolefin wax is typically 0.01 to 10% by mass, preferably 0.05 to 5% by mass, relative to the modified polyolefin wax.

[0159] Specifically, examples of the haloformyl groups mentioned above include chloroformyl groups and bromoformyl groups. The means by which these functional groups are imparted to the polyolefin wax may be any conventionally known method, and specifically, any method such as copolymerization with a compound having a functional group or post-processing such as oxidation may be used. The functional group is preferably a carboxyl group because it has a suitable affinity for polyester resin.

[0160] The concentration of carboxyl groups in modified polyolefin wax can be appropriately selected and determined, but if it is too low, the affinity with polyester resin will be small, the effect of suppressing volatile matter will be small, and the bonding strength may decrease. Conversely, if the concentration is too high, for example, the polymer main chain constituting the polyolefin wax may be excessively cleaved during modification, causing the molecular weight of the modified polyolefin wax to decrease too much, resulting in increased volatile matter generation and clouding on the surface of the polyester resin molded product. As the modified polyolefin wax, polyethylene oxide wax is preferred.

[0161] Among the low molecular weight compounds (c), it is preferable that the melting point is 40 to 140°C, more preferably 45°C or higher, and more preferably 50°C or higher, while it is even more preferable that the melting point is 135°C or lower, and more preferably 130°C or lower.

[0162] Furthermore, the low-molecular-weight compound may be present as a single compound, or as two or more compounds in any combination and ratio.

[0163] The low molecular weight compound (c) is preferably included in a proportion of 0 to 1.5 parts by mass per 100 parts by mass of the thermoplastic resin composition (A), more preferably in a proportion of 0.001 to 1.5 parts by mass, and more preferably in a proportion of 0.01 parts by mass or more, particularly 0.1 parts by mass or more, and even more preferably in a proportion of 0.2 parts by mass or more, while more preferably in a proportion of 1.4 parts by mass or less, and even more preferably 1.2 parts by mass or less.

[0164] (Polyolefin wax) From the viewpoint of suppressing gas generation when the thermoplastic resin composition (A) is heated, it is preferable to select polyolefin wax as the low molecular weight compound (c).

[0165] Examples of polyolefins include polyethylene, polypropylene, polyisobutylene, polyisoprene, polybutadiene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, and ethylene-vinyl chloride copolymer.

[0166] Among these, it is preferable to select oxidized polyolefin wax from the viewpoint of suppressing gas generation when the thermoplastic resin composition (A) is heated, and among these, it is most preferable to select oxidized polyethylene wax. Oxidized polyethylene wax is a compound obtained by oxidizing polyethylene and introducing polar groups into it. Examples of such polar groups include carboxyl groups, amino groups, and hydroxyl groups.

[0167] From the viewpoint of suppressing gas generation when the thermoplastic resin composition (A) is heated, the number average molecular weight of the oxidized polyethylene wax is more preferably 1500 or more, more preferably 2000 or more, more preferably 2500 or more, more preferably 3000 or more, and more preferably 3500 or more. On the other hand, from the viewpoint of improving bonding strength, it is more preferably 5000 or less, more preferably 4500 or less, and more preferably 4200 or less.

[0168] The acid value of the above-mentioned polyethylene oxide wax is preferably 0.01 to 40 mgKOH / g, and more preferably 0.1 mgKOH / g or more or 30 mgKOH / g or less, of which 0.5 mgKOH / g or more or 20 mgKOH / g or less, and of which 0.7 mgKOH / g or more or 10 mgKOH / g or less.

[0169] From the viewpoint of suppressing gas generation when the thermoplastic resin composition (A) is heated, the polyolefin wax as the low molecular weight compound (c) is preferably included in a ratio of 0.01 to 1.5 parts by mass per 100 parts by mass of the thermoplastic resin composition (A), and more preferably 0.1 parts by mass or more or 1.0 part by mass or less, and more preferably 0.2 parts by mass or more or 0.7 parts by mass or less.

[0170] <Other resin components> The thermoplastic resin composition (A) may contain other resins or compounds in addition to those mentioned above. For example, one or more combinations selected from the group consisting of carbodiimide compounds, compounds having an oxazoline group (ring), compounds having an oxazine group (ring), compounds having a carboxylic acid, and compounds having an amide group can be cited. Furthermore, it may also include, for example, polysulfone resin, polyethersulfone resin, polyetherimide resin, polyetherketone resin, fluororesin, etc. However, the proportion of other resins in the thermoplastic resin composition (A) is preferably 20% by mass or less, and more preferably 10% by mass or less.

[0171] (Carbodiimide compounds) The above-mentioned carbodiimide compounds are compounds that contain a carbodiimide group (-N=C=N-) in their molecules. Any of the following can be used as the carbodiimide compound: aliphatic carbodiimide compounds with an aliphatic main chain, alicyclic carbodiimide compounds with an alicyclic main chain, or aromatic carbodiimide compounds with an aromatic main chain. Among these, the use of alicyclic carbodiimide compounds is preferred because it can improve the hydrolysis resistance of the resin-metal composite. The carbodiimide compound may be of monomeric or polymeric form, but in the present invention, the polymeric form is preferred. In the case of polymer-type carbodiimides, the preferred number-average molecular weight is preferably 10,000 or less, more preferably 4,000 or less, with a lower limit of preferably 100 or more, and more preferably 500 or more.

[0172] The amount of carbodiimide groups contained in the carbodiimide compound is preferably 100 to 1000 (g / mol) in carbodiimide equivalents (weight of the carbodiimide compound to give 1 mol of carbodiimide groups [g]), more preferably 200 (g / mol) or more or 800 (g / mol) or less, and more preferably 235 (g / mol) or more or 650 (g / mol) or less.

[0173] Examples of the above-mentioned aliphatic carbodiimide compounds include diisopropylcarbodiimide and dioctyldecylcarbodiimide. Examples of the above-mentioned alicyclic carbodiimide compounds include dicyclohexylcarbodiimide and poly(4,4'-dicyclohexylmethanecarbodiimide), with poly(4,4'-dicyclohexylmethanecarbodiimide) being particularly preferred. Examples of commercially available products include "Carbodilite" (product name; manufactured by Nisshinbo Chemical Co., Ltd.).

[0174] The above-mentioned aromatic carbodiimide compounds include diphenylcarbodiimide, di-2,6-dimethylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, di-p-nitrophenylcarbodiimide, di-p-aminophenylcarbodiimide, di-p-hydroxyphenylcarbodiimide, di-p-chlorophenylcarbodiimide, di-p-methoxyphenylcarbodiimide, di-3,4-dichlorophenylcarbodiimide, di-2,5-dichlorophenylcarbodiimide, di-o-chlorophenylcarbodiimide, p-phenylene-bis-di-o-triylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, p-phenylene-bis-di-p-chlorophenylcarbodiimide, and ethylene-bis-diphenyl Examples include mono- or dicarbodiimide compounds such as ylcarbodiimide, and polycarbodiimide compounds such as poly(4,4'-diphenylmethanecarbodiimide), poly(3,5'-dimethyl-4,4'-biphenylmethanecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(3,5'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(1,3-diisopropylphenylenecarbodiimide), poly(1-methyl-3,5-diisopropylphenylenecarbodiimide), poly(1,3,5-triethylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide), and two or more of these can be used in combination. Among these, di-2,6-dimethylphenylcarbodiimide, poly(4,4'-diphenylmethanecarbodiimide), poly(phenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide) are particularly preferred. Examples of commercially available products include "Stavauxol P" (product name; manufactured by BASF).

[0175] (Compounds containing an oxazoline group (ring)) Examples of compounds having the above-mentioned oxazoline group (ring) include oxazolines, alkyloxazolines (C1-4 alkyloxazolines such as 2-methyloxazoline and 2-ethyloxazoline), and bisoxazoline compounds.

[0176] Examples of the above bisoxazoline compounds include 2,2'-bis(2-oxazoline), 2,2'-bis(alkyl-2-oxazoline) [such as 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(4-ethyl-2-oxazoline), 2,2'-bis(4,4-dimethyl-2-oxazoline), etc., 2,2'-bis(C1-6alkyl-2-oxazoline)], 2,2'-bis(aryl-2-oxazoline) [such as 2,2'-bis(4-phenyl-2-oxazoline)], 2,2'-bis(cycloalkyl-2-oxazoline) [2, [2'-bis(4-cyclohexyl-2-oxazoline), etc.], 2,2'-bis(aralkyl-2-oxazoline) [2,2'-bis(4-benzyl-2-oxazoline), etc.], 2,2'-alkylenebis(2-oxazoline) [2,2'-ethylenebis(2-oxazoline), 2,2'-tetramethylenebis(2-oxazoline), etc., 2,2'-C1-10 alkylenebis(2-oxazoline), etc.], 2,2'-alkylenebis(alkyl-2-oxazoline) [2,2'-ethylenebis(4-methyl-2-oxazoline), 2,2'-tetramethylenebis(4-methyl-2-oxazoline), etc.] [2,2'-C1-10 alkylenebis(C1-6 alkyl-2-oxazoline), etc. such as ethylenebis(4,4-dimethyl-2-oxazoline), 2,2'-arylenebis(2-oxazoline), [2,2'-(1,3-phenylene)-bis(2-oxazoline), 2,2'-(1,4-phenylene)-bis(2-oxazoline), 2,2'-(1,2-phenylene)-bis(2-oxazoline), 2,2'-diphenylenebis(2-oxazoline), etc.], 2,2'-arylenebis(alkyl-2-oxazoline), [2,2'-(1,3-phenylene )-bis(4-methyl-2-oxazoline), 2,2'-(1,4-phenylene)-bis(4,4-dimethyl-2-oxazoline), etc., 2,2'-phenylene-bis(C1-6 alkyl-2-oxazoline), 2,2'-allyloxyalkanebis(2-oxazoline), etc., 2,2'-9,9'-diphenoxyethanebis(2-oxazoline), etc., 2,2'-cycloalkylenebis(2-oxazoline), etc., 2,2'-cycloalkylenebis(2-oxazoline), etc., 2,2'-cyclohexylenebis(2-oxazoline), etc., N,N'-alkylenebis(2-carbamoyl-2-oxazoline) [N,N'-ethylenebis(2-carbamoyl-2-oxazoline), N,N'-tetramethylenebis(2-carbamoyl-2-oxazoline), etc., N,N'-C1-10 alkylenebis(2-carbamoyl-2-oxazoline), N,N'-alkylenebis(2-carbamoyl-alkyl-2-oxazoline) [N,N'-ethylenebis(2-carbamoyl-4-methyl-2-oxazoline] Examples include N,N'-C1-10 alkylenebis (2-carbamoyl-C1-6 alkyl-2-oxazoline), such as N,N'-tetramethylenebis(2-carbamoyl-4,4-dimethyl-2-oxazoline), and N,N'-arylenebis(2-carbamoyl-2-oxazoline) [e.g., N,N'-phenylenebis(2-carbamoyl-oxazoline)].

[0177] Furthermore, compounds containing an oxazoline group also include vinyl polymers containing an oxazoline group [such as the Epocross RPS series, RAS series, and RMS series manufactured by Nippon Shokubai Co., Ltd.]. Among these oxazoline compounds, bisoxazoline compounds are preferred.

[0178] (Compounds containing an oxazine group (ring)) As the compound having the above-mentioned oxazine group (ring), oxazines, bisoxazine compounds, and the like can be used.

[0179] Examples of the above bisoxazine compounds include 2,2'-bis(5,6-dihydro-4H-1,3-oxazine), 2,2'-bis(alkyl-5,6-dihydro-4H-1,3-oxazine) [such as 2,2'-bis(4-methyl-5,6-dihydro-4H-1,3-oxazine), 2,2'-bis(4,4-dimethyl-5,6-dihydro-4H-1,3-oxazine), 2,2'-bis(4,5-dimethyl-5,6-dihydro-4H-1,3-oxazine), etc., 2,2'-bis(C1-6alkyl-5,6-dihydro-4H-1,3-oxazine)], 2, 2'-alkylenebis(5,6-dihydro-4H-1,3-oxazine) [2,2'-methylenebis(5,6-dihydro-4H-1,3-oxazine), 2,2'-ethylenebis(5,6-dihydro-4H-1,3-oxazine), 2,2'-hexanemethylenebis(5,6-dihydro-4H-1,3-oxazine), etc., 2,2'-C1-10 alkylenebis(5,6-dihydro-4H-1,3-oxazine), etc.], 2,2'-arylenebis(5,6-dihydro-4H-1,3-oxazine) [2,2'-(1,3-phenylene)-bis(5,6-dihydro N,N'-4H-1,3-oxazine, 2,2'-(1,4-phenylene)-bis(5,6-dihydro-4H-1,3-oxazine), 2,2'-(1,2-phenylene)-bis(5,6-dihydro-4H-1,3-oxazine), 2,2'-naphthylenebis(5,6-dihydro-4H-1,3-oxazine), 2,2'-diphenylenebis(5,6-dihydro-4H-1,3-oxazine), etc., N,N'-alkylenebis(2-carbamoyl-5,6-dihydro-4H-1,3-oxazine) [N,N'-ethylenebis(2-carbamoyl-5,6-dihydro N,N'-C1-10 alkylenebis(2-carbamoyl-5,6-dihydro-4H-1,3-oxazine), N,N'-tetramethylenebis(2-carbamoyl-5,6-dihydro-4H-1,3-oxazine), N,N'-alkylenebis(2-carbamoyl-alkyl-5,6-dihydro-4H-1,3-oxazine) [N,N'-ethylenebis(2-carbamoyl-4-methyl-5,6-dihydro-4H-1,3-oxazine), N,N'-hexamethylenebis(2-carbamoyl-4,4-dimethyl-5,Examples include N,N'-C1-10 alkylenebis(2-carbamoyl-C1-6 alkyl-5,6-dihydro-4H-1,3-oxazine), N,N'-arylenebis(2-carbamoyl-5,6-dihydro-4H-1,3-oxazine), and N,N'-phenylenebis(2-carbamoyl-oxazine). Among these oxazine compounds, bisoxazine compounds are preferred.

[0180] (Compounds containing carboxylic acids) Examples of compounds having the above-mentioned carboxylic acid include formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid, oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, adipic acid, benzoic acid, phthalic acid, terephthalic acid, lactic acid, malic acid, tartaric acid, diphenolic acid benzenesulfonic acid, toluenesulfonic acid, dodecylbenzenesulfonic acid, nonylbenzenesulfonic acid, nitrobenzenesulfonic acid, cyanobenzenesulfonic acid, hydroxybenzenesulfonic acid, methylsulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, nitrobenzenecarboxylic acid, cyanobenzenecarboxylic acid, hydroxybenzenecarboxylic acid, hydroxyacetic acid, and their salts.

[0181] (Compounds containing an amide group) Examples of compounds having the above-mentioned amide group include (meth)acrylamide, N-methylmethacrylamide, methylolated acrylamide, methylolated methacrylamide, ureidovinyl ether, β-ureidoisobutylvinyl ether, and ureidoethyl acrylate.

[0182] <Fibrous reinforced filler (d)> The thermoplastic resin composition (A) contains a fibrous reinforcing filler (d), such as glass fibers. The inclusion of the fibrous reinforcing filler (d) improves the bonding between the metal component (X) and the resin component (Y). Furthermore, the strength, rigidity, and dimensional stability of the thermoplastic resin composition (A) or the resin-metal composite can be improved.

[0183] The average fiber diameter (Fd) of the fibrous reinforcing filler is not particularly limited, but it is preferably selected within the range of 1 to 100 μm. If the average fiber diameter of the fibrous reinforcing filler is 1 μm or more, manufacturing is easy and costs can be kept down. On the other hand, if it is 100 μm or less, the tensile strength of the fibrous reinforcing filler can be maintained. In particular, from the viewpoint of increasing bonding strength, the average fiber diameter of the fibrous reinforcing filler is more preferably 4 to 9 μm, more preferably 5 to 8 μm, and even more preferably 6 to 7 μm. The fiber cross-section can be circular or flattened.

[0184] The thermoplastic resin composition (A) preferably contains fibrous reinforcing filler (d) in a ratio of 10 to 100 parts by mass per 100 parts by mass of thermoplastic resin composition (A). If the content is too low, the reinforcing effect may not be sufficient, and if it is too high, the appearance and impact resistance may be poor, and the fluidity may not be sufficient. From this viewpoint, a particularly preferred content of the fibrous reinforcing filler (d) is 15 parts by mass or more, more preferably 20 parts by mass or more, especially 25 parts by mass or more, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, and especially 50 parts by mass or less, per 100 parts by mass of the thermoplastic resin composition (A).

[0185] Glass fibers are particularly preferred as the fibrous reinforcing filler (d). There are no particular restrictions on the type of glass fiber, and examples include glass fibers such as E glass, C glass, A glass, and S glass. Among these, E glass fibers are preferred because they do not adversely affect the thermal stability of the thermoplastic resin composition (A).

[0186] Glass fibers may be used in combination of two or more types, depending on the required properties.

[0187] Furthermore, it is preferable that the ratio (Fd / Rz) of the average fiber diameter (Fd) of the fibrous reinforcing filler (d) to the maximum height (Rz) of the surface of the metal member (X), measured in accordance with JIS B 0601:2001, is 0.1 or greater. If the ratio (Fd / Rz) of the average fiber diameter (Fd) of the fibrous reinforcing filler to the maximum surface height (Rz) of the metal member (X) is 1.0 or less, the probability of glass fibers penetrating into the irregularities of the metal surface increases, which is preferable because it improves the bonding strength with the metal. From this perspective, the ratio (Fd / Rz) is preferably 1.0 or less, and more preferably 0.8 or less, 0.5 or less, 0.3 or less, and 0.1 or less. While there is no particular lower limit to the ratio (Fd / Rz), from the viewpoint of bonding strength with metal members, it is preferable that it be 0.01 or higher, and more preferably 0.02 or higher.

[0188] As mentioned above, the recesses on the surface of the metal member (X) do not need to have a uniform opening diameter and depth. However, the penetration of the fibrous reinforcing filler into the recesses strengthens the rigidity of the joint interface, thereby obtaining high joint strength and airtightness. For this purpose, it is preferable that the opening diameter of the recesses is equal to or greater than the average fiber diameter (Fd) of the fibrous reinforcing filler. In this case, the opening diameter is preferably 10 μm or more and 300 μm or less, more preferably 20 μm or more and 250 μm or less, and even more preferably 40 μm or more and 200 μm or less. The depth is preferably 10 μm or more and 500 μm or less, more preferably 30 μm or more and 300 μm or less, and even more preferably 40 μm or more and 250 μm or less. Furthermore, for example, when observing the cross-section of the joint at a scanning electron microscope (Hitachi High-Tech, S3400) at 100x magnification, it is preferable that there are two or more recesses within a 1 mm length of the metal surface, and more preferably four or more recesses, as this results in higher joint strength.

[0189] The average fiber length of the fibrous reinforcing filler after molding of the resin-metal composite is not particularly limited. However, if the average fiber length of the fibrous reinforcing filler is too short, the reinforcing effect may not be sufficiently realized, and if it is too long, the bonding strength between the metal member (X) and the resin member (Y) of the resin-metal composite may decrease. From this viewpoint, the average fiber length is preferably 50 to 800 μm, more preferably 100 to 750 μm, more preferably 150 to 700 μm, and more preferably 200 to 650 μm. The average fiber length is calculated using an image analysis device (WinROOF2015 manufactured by Mitani Corporation) from images obtained by observing 2,000 fibrous reinforced fillers from the filler residue collected during processing such as high-temperature ashing, solvent dissolution, and chemical decomposition of molded products using an optical microscope (OLYMPUS B201). Furthermore, a method of forming long fiber pellets by impregnating the roving of the fibrous reinforcing filler with a thermoplastic resin composition (A) in a wire coating method is undesirable because it may reduce the bonding strength of the resin-metal composite.

[0190] The fibrous reinforcing filler used in the present invention can be surface-treated with a coupling agent such as aminosilane or epoxysilane to improve its adhesion to the thermoplastic resin composition (A). Examples of coupling agents include chlorosilane compounds such as vinyltrichlorosilane and methylvinyldichlorosilane; alkoxysilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and γ-methacryloxypropyltrimethoxysilane; epoxysilane compounds such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane; as well as acrylic compounds, isocyanate compounds, titanate compounds, and epoxy compounds.

[0191] Furthermore, the fibrous reinforcing filler (d) such as glass fibers used in the present invention is usually preferably used as chopped strands (chopped glass fibers, etc.) obtained by bundling many of these fibers together and cutting them to a predetermined length, and in this case, it is preferable to blend a converging agent into the fibrous reinforcing filler. Blending a converging agent has the advantage of increasing the production stability of the thermoplastic resin composition (A), as well as obtaining good mechanical properties. There are no particular restrictions on the sizing agent for the fibrous reinforcing filler. Examples include resin emulsions such as vinyl acetate resin, ethylene-vinyl acetate copolymer, acrylic resin, epoxy resin, polyurethane resin, and polyester resin, with acrylic resin, epoxy resin, and polyurethane resin being preferred.

[0192] The thermoplastic resin composition (A) may also preferably contain other inorganic fillers in the form of plates, granules, or amorphous materials, in addition to the fibrous reinforcing filler described above. Plate-shaped inorganic fillers exhibit functions that reduce anisotropy and warping, and examples include talc, glass flakes, mica, kaolin, and metal foil. Among plate-shaped inorganic fillers, glass flakes are preferred. Other granular or amorphous inorganic fillers include, for example, ceramic beads, clay, zeolite, barium sulfate, titanium dioxide, silicon dioxide, aluminum oxide, magnesium hydroxide, and zinc sulfide. Other preferred inorganic fillers include talc, titanium oxide, and zinc sulfide.

[0193] <Other ingredients> The thermoplastic resin composition (A) may contain other components in addition to those mentioned above. Examples include stabilizers, mold release agents, colorants, elastomers, flame retardants, flame retardant enhancers, anti-dripping agents, UV absorbers, antistatic agents, anti-fogging agents, lubricants, anti-blocking agents, plasticizers, dispersants, and antibacterial agents. The elastomer can be one of those described in paragraphs 0050 to 0076 of Japanese Patent No. 6604977. The flame retardant can be one of those described in paragraphs 0071 to 0076 of Japanese Patent Publication No. 6518479.

[0194] <<Method for manufacturing this resin-metal composite>> Next, the manufacturing method for this resin-metal composite will be described. The method for manufacturing this resin-metal composite is not particularly limited, and examples include a method of filling a thermoplastic resin composition (A) into a mold and molding it. Specifically, injection molding, extrusion molding, compression molding, etc., can be mentioned. Among these, injection molding methods such as insert molding are common.

[0195] <Insert molding> In the case of insert molding, a metal member (X) having an uneven surface is pre-installed in the molding die, and a molten thermoplastic resin composition (A) is filled into the die and cooled. By using this insert molding method, the resin component (Y) can be molded and simultaneously joined to the surface of the metal component (X), which has surface irregularities. This makes it possible to firmly and stably join the metal component (X) and the resin component (Y), which would otherwise be difficult to bond or weld together.

[0196] The thermoplastic resin composition (A) can be prepared according to conventional methods. Typically, each component and various additives, which may be added as desired, are mixed together and then melt-kneaded in a single-screw or twin-screw extruder. Alternatively, the thermoplastic resin composition (A) of the present invention can be prepared by not pre-mixing each component, or by pre-mixing only a portion of the components, supplying them to the extruder using a feeder, and melt-kneading them. Furthermore, when incorporating fibrous reinforcing filler (d), it is also preferable to supply it from a side feeder located in the middle of the extruder cylinder.

[0197] The melting temperature of the thermoplastic resin composition (A), in other words, the heating temperature during melt mixing, is usually preferably selected appropriately from the range of 220 to 300°C. If this temperature is too high, decomposition gases are likely to be generated, and therefore, it is desirable to select a screw configuration that takes shear heating and other factors into consideration.

[0198] On the other hand, the size and shape of the metal component (X) to be installed inside the mold can be determined appropriately based on the size, structure, etc., of the resin-metal composite.

[0199] The size, shape, and thickness of this resin-metal composite are not particularly limited and may be plate-shaped (disc, polygon, etc.), columnar, box-shaped, bowl-shaped, tray-shaped, etc. These shapes may be formed by casting, press molding, etc., before the metal component (X) is pre-installed in the molding die, or they may be formed after composite formation. Alternatively, they may be formed in the die simultaneously with or immediately before injection molding using a composite molding machine equipped with a press function. In the case of large or complex composites, the thickness of all parts of the composite does not need to be uniform, and reinforcing ribs may be provided in the composite. Furthermore, the metal component (X) does not need to extend throughout the entire resin-metal composite; it may be a part of it.

[0200] When insert molding, optimizing the combination of the temperature of the molten thermoplastic resin composition (A) and the temperature of the metal component (X) is useful for improving the bonding strength. Methods for achieving this include preheating the metal component (X) to be placed inside the mold, or heating the mold itself.

[0201] Methods for preheating the metal component (X) to be placed inside the mold include induction heating before insert molding the metal component (X), heating with an induction heater, hot plate, heating furnace, etc., heating the area near the bonding region with the thermoplastic resin composition from the outside with a halogen lamp, dryer, etc. after inserting the metal component (X) into the mold, and heating the inside of the mold with a cartridge heater, etc. after inserting the metal component (X) into the mold. Among these, locally heating only the bonding region with the thermoplastic resin composition (A) is the most useful. Furthermore, "localized heating" includes cases where, depending on the heating method, the area surrounding the joint is heated, but parts of the metal member (X) that are far from the joint are not heated.

[0202] When heating the mold, if the mold temperature is too low, the inserted metal component (X) may not be heated sufficiently, potentially resulting in insufficient bonding strength. In particular, in the case of this resin-metal composite, it is necessary for the resin to penetrate sufficiently into the irregularities on the surface of the metal component (X) before solidification. Therefore, it is preferable to heat the mold to a higher temperature than usual, such as by heating it locally as needed. On the other hand, if the temperature is too high, it may affect the resin itself, potentially resulting in a composite that is not of good quality. From this viewpoint, in the method for manufacturing the resin-metal composite, it is preferable to set the surface temperature of the mold in contact with the metal member (X) when it is mounted in the mold to a temperature 60 to 100°C higher than the glass transition temperature of the thermoplastic resin, for example, polyester (a-1), and more preferably to set it to a temperature 65 to 95°C higher, of which 68 to 95°C higher, and of which 70 to 93°C higher.

[0203] <<This resin-metal composite form>> This resin-metal composite can be formed into any desired shape. As an example of the form of this resin-metal composite, as shown in Figures 1 and 2, a resin member (Y) having the shape of an in-vehicle component can be provided with a peripheral wall Y1 that surrounds the peripheral edge of a plate-shaped metal member (X).

[0204] The metal member (X) is formed by applying a ridged treatment to the bonding region of a plate-shaped metal substrate to create a textured surface. As shown in Figure 2, at the peripheral edge of the metal member (X), the resin member (Y) covers the edge on the back side of the metal member (X) from the front edge to the back edge via the side end surface, and the textured portion on the front side of the metal member (X) and the thermoplastic resin composition (A) of the resin member (Y) are bonded together at the front edge and the back edge of the metal member (X) (joint (J)).

[0205] Note that the configurations shown in Figures 1 and 2 are merely examples. The shapes of the metal component (X) and the resin component (Y) can be arbitrarily changed. Furthermore, this resin-metal composite can be formed by combining metal components (X) of various configurations with resin components (Y) of various configurations.

[0206] Furthermore, as illustrated in Figures 3(a) to (e), the bonding state between the metal member (X) and the resin member (Y) can also be arbitrarily changed. For example, as shown in Figure 3(a), the metal member (X) may be made by roughening one side of a metal substrate to form irregularities on the metal surface, and the resin member (Y) may cover the edge on the back side of the metal member (X) from the front side edge to the back side edge via the end face, and the irregular surface of the metal member (X) and the resin member (Y) may be joined only on one side of the edge of the metal member (X) (joint (J)). As shown in Figure 3(b), the metal member (X) may be made by applying a textured treatment to one side of a metal substrate to form irregularities on the metal surface, and the resin member (Y) may cover the peripheral edge of the metal member (X) from the surface edge to the end face, and the textured surface of the metal member (X) and the resin member (Y) may be joined only on one side of the edge of the metal member (X) (joint (J)).

[0207] As shown in Figure 3(c), the metal member (X) may be made by applying a textured treatment to one side of a metal substrate to form irregularities on the metal surface, and the edge of one side surface of the metal member (X) and the edge of one side surface of the resin member (Y) may overlap with an appropriate width, so that the textured surface of the metal member (X) and the resin member (Y) are joined at this point (joint (J)). As shown in Figure 3(d), the metal member (X) may be made by applying a textured treatment to both sides of a metal substrate to form irregularities on the metal surface, and the resin member (Y) may cover the peripheral edge of the metal member (X) from the surface edge to the end face, and the textured surface of the metal member (X) and the resin member (Y) may be joined only on one side of the edge of the metal member (X) (joint (J)). As shown in Figure 3(e), the metal member (X) may be made by applying a textured treatment to both sides of a metal substrate to form irregularities on the metal surface, and the edge of one side surface of the metal member (X) and the edge of one side surface of the resin member (Y) may overlap with an appropriate width, so that the textured surface of the metal member (X) and the resin member (Y) are joined at this point (joint (J)).

[0208] A larger ratio (S1 / S2) between the bonding area (S1) of the metal member (X) and the resin member (Y) and the area (S2) of the metal member (X) that is exposed and not covered by the resin member (Y) is preferable because it ensures stable adhesion and improves airtightness. Specifically, the ratio (S1 / S2) is preferably 0.01 or greater, more preferably 0.1 or greater, and particularly preferable 0.5 or greater, as this provides sufficient airtightness. Furthermore, a relatively small ratio is preferable in order to ensure heat dissipation from the exposed metal parts. Specifically, the ratio (S1 / S2) is preferably 8 or less, more preferably 4 or less, even more preferably 2 or less, and particularly preferable if it is 1 or less, as this ensures sufficient heat dissipation.

[0209] By joining S1 / S2 in this ratio, the joint strength and airtightness can be increased, and when used as a component of an enclosure, sufficient heat can be released from inside the enclosure, ensuring good heat dissipation. Furthermore, when the metal surface has irregularities on both sides, the area of ​​the joint (J)(J) between the irregular surface of the metal member (X) and the resin member (Y) does not need to be the same on both sides.

[0210] <<Bonding strength of this resin-metal composite>> This resin-metal composite can achieve excellent bonding strength by having a structure in which the uneven surface of a metal member (X) and a resin member (Y) are joined together. In this resin-metal composite, the bonding strength between the metal member (X) and the resin member (Y) is preferably 26 MPa or higher, more preferably 27 MPa or higher, even more preferably 28 MPa or higher, even more preferably 29 MPa or higher, and particularly preferably 30 MPa or higher. Higher bonding strength is preferable because it improves airtightness.

[0211] In the present invention, "joint strength" means a value obtained by measurement in accordance with ISO 19095, that is, a test piece for joint strength testing with the shape described in the example is prepared, a metal member (X) and a resin member (Y) are joined using the joining conditions for manufacturing a resin-metal composite, and the resulting composite is subjected to the tensile test described in the example and the value obtained by measurement.

[0212] <<Applications of this resin-metal composite>> This resin-metal composite can firmly and stably bond metal and resin components, achieving excellent bonding strength. Moreover, it combines the properties of both materials, such as heat dissipation, heat resistance, insulation, and antistatic properties, making it suitable for a variety of applications. In particular, it is suitable for automotive applications where bonding strength and heat dissipation are especially required.

[0213] Specifically, by forming a container using this resin-metal composite, such a container can be made with excellent airtightness, heat dissipation, heat resistance, insulation, and antistatic properties, and can therefore be used for vehicle components, electrical components, and housing components. Specifically, it can be suitably used in applications that require strong bonding strength as a functional requirement, such as for general home appliances, electrical and electronic components (housings, cases, covers, etc.) incorporated into office automation equipment, mechanical components, and components that constitute part or all of the housing of vehicle electrical components (various control units, ignition coil components, sensor components, motor components, power modules, boost DC / DC converters, step-down DC / DC converters, capacitors, insulators, motor terminal blocks, batteries, electric compressors, battery current sensors, and junction blocks, etc.), as well as for smartphone housings. In particular, the resin component of the present invention has a relative permittivity of 3.3 to 3.7, especially 3.4 to 3.6, and a dielectric loss tangent of around 0.01, for example 0.005 to 0.015, making it suitable for use in automotive sensor components, radome components, ECU cases, millimeter-wave radar cases, and the like.

[0214] Figure 4 shows an example in which this resin-metal composite was applied as part of the housing for an electrical component in a vehicle. When this resin-metal composite is used as part of a product, that is, when it is used in combination with other components (Z) (such as resin molded bodies, aluminum die-casts, or metals), any method can be used to join the other components (Z) to this resin-metal composite, for example, the joining method between the resin component (Y) and the other components (Z). Examples include laser welding, ultrasonic welding, vibration welding, heat welding, mechanical joining using bolts or tapping screws, and adhesives.

[0215] <<Explanation of terms>> In this invention, when "X~Y" (where X and Y are any numbers) is written, unless otherwise specified, it means "X or greater and Y or less," and also includes the meaning of "preferably greater than X" or "preferably less than Y." In addition, when it is described as "X or more" (X is an arbitrary number), unless otherwise specified, it includes the meaning of "preferably greater than X", and when it is described as "Y or less" (Y is an arbitrary number), unless otherwise specified, it also includes the meaning of "preferably less than Y".

Examples

[0216] Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[0217] <Metal member (X1)> As follows, a metal surface treatment method A was applied to a metal member to obtain a metal member (X1) as a metal member (X). Metal surface treatment method A: A metal plate made of an aluminum alloy (JIS H4000 "A5052") in the shape of a strip with a length of 45 mm, a width of 12 mm, and a thickness of 1.5 mm was immersed in the following zincate solution (40.0 °C) for 60 seconds. Next, it was immersed in the following etching agent (50 °C) for 480 seconds to roughen the surface of the metal plate to form a concavo-convex surface. Next, the metal plate was immersed in a commercially available zirconium chemical conversion treatment agent (manufactured by Nippon Parkerizing Co., Ltd. "Parside (registered trademark)", concentration 50 g / L, temperature 45 °C, pH 4.0) for 120 seconds to obtain a metal member (X1).

[0218] <Zincate solution components> · Water · Zinc oxide: 0.25 mol / L · Sodium hydroxide: 3.80 mol / L · Tartaric acid: 0.07 mol / L · pH: 12.5

[0219] <Etching agent components> · Water · Sodium peroxodisulfate: 0.35 mol / L · Potassium chloride: 1.40 mol / L · pH: 3.0

[0220] The uneven surface of the metal component (X1) processed as described above was observed with a 20x objective lens of a hybrid laser microscope (LASERTEC OPTELICS HYBRID), and the surface roughness was measured in accordance with JIS B 0601:2001 using the included analysis software (Lasertec Microscope Solution Software LMeye7) at 20x objective lens. Measurements were taken using the Fine Peak measurement algorithm to obtain an FZ image of the average surface irregularities at the center of a metal plate made of aluminum alloy (JIS H4000 "A5052"), which was shaped like a strip with dimensions of 45 mm in length, 12 mm in width, and 1.5 mm in thickness. The measurement range was 4.2 mm in the 45 mm length direction. The cutoff value λc was 0.8000 mm. The same operation was repeated 30 times at arbitrarily different locations, and the average value was calculated. The arithmetic mean roughness (Ra) was 5.2 μm, and the maximum height (Rz) was 34.7 μm. Furthermore, surface and cross-sectional observation using an electron microscope (Hitachi High-Tech S3400) revealed a size distribution consisting of large depressions with aperture diameters of 40-190 μm and depths of 10-80 μm, and small depressions with aperture diameters of 0.1-5 μm and depths of 0.1-5 μm. These small depressions were distributed within and around the larger depressions.

[0221] <Metal parts (X2)> A metal component (X2) was obtained as a metal component (X) by applying metal surface treatment method B to a metal component as follows. Metal surface treatment method B: A metal plate made of aluminum alloy (JIS H4000 "A5052"), measuring 45 mm in length, 12 mm in width, and 1.5 mm in thickness, was immersed in the following treatment solution (1) for 300 seconds as the first step, then immersed in the following treatment solution (2) for 180 seconds as the second step, and immersed in the following treatment solution (3) for 120 seconds as the third step to obtain a metal component (X2).

[0222] Treatment solution (1): In the desired volume, lithium chloride at a concentration of 3.0 mol / L and magnesium nitrate hexahydrate at a concentration of 0.1 mol / L were added to deionized water. The pH was measured using a handheld pH meter (HM-30P portable pH meter manufactured by Toa DKK Co., Ltd.) and a pH measuring electrode (GST-2739C manufactured by the same company), and the solution was adjusted to pH 10.0 using nitric acid and sodium hydroxide, and then adjusted to the target volume. The temperature of treatment solution (1) was set to 60°C. Treatment solution (2): Nitric acid was added to deionized water to a concentration of 6.5 mol / L. In this example, pH adjustment was not performed. The temperature of treatment solution (2) was set to 50°C. Treatment solution (3): A commercially available zirconium chemical treatment agent (Palseed®, manufactured by Nippon Parkerizing Co., Ltd.) was added to deionized water to a concentration of 50 g / L. The solution was then adjusted to pH 4.0 using sodium hydroxide and adjusted to the target volume. The temperature of treatment solution (3) was set to 50°C.

[0223] The uneven surface of the metal component (X2) processed as described above was observed with a 20x objective lens of a hybrid laser microscope (LASERTEC OPTELICS HYBRID), and the surface roughness was measured in accordance with JIS B 0601:2001 using the included analysis software (Lasertec Microscope Solution Software LMeye7) at 20x objective lens. Measurements were taken using the Fine Peak measurement algorithm to obtain an FZ image of the average surface irregularities at the center of a metal plate made of aluminum alloy (JIS H4000 "A5052"), which was shaped like a strip with dimensions of 45 mm in length, 12 mm in width, and 1.5 mm in thickness. The measurement range was 4.2 mm in the 45 mm length direction. The cutoff value λc was 0.8000 mm. The same operation was repeated 30 times at arbitrarily different locations, and the average value was calculated. The arithmetic mean roughness (Ra) was 0.4 μm, and the maximum height (Rz) was 4.8 μm. Surface and cross-sectional observation using an electron microscope (Hitachi High-Tech S3400) revealed an aperture diameter of 10-150 nm and a depth of 300-800 μm.

[0224] <Metal parts (X3)> A metal component (X3) was obtained as a metal component (X) by applying metal surface treatment method C to a metal component as follows. Metal surface treatment method C: Using a fiber laser with a wavelength of 1064 nm (Panasonic LP-M500), a metal plate made of aluminum alloy (JIS H4000 "A5052") with dimensions of 45 mm in length, 12 mm in width, and 1.5 mm in thickness was subjected to laser treatment to create uneven surfaces. The above laser processing was performed by combining two hatching widths: one with an output of 40W, a scan speed of 1500mm / s, a pulse period of 20μs, and a hatching width of 0.10mm, and another with a scan speed of 1000mm / s, a pulse period of 20μs, and a hatching width of 0.12mm, in a grid pattern, and scanning 10 times in each direction.

[0225] The uneven surface of the metal component (X3) processed as described above was observed with a 20x objective lens of a hybrid laser microscope (LASERTEC OPTELICS HYBRID), and the surface roughness was measured in accordance with JIS B 0601:2001 using the included analysis software (Lasertec Microscope Solution Software LMeye7) at 20x objective lens. Measurements were taken using the Fine Peak measurement algorithm to obtain an FZ image of the average surface irregularities at the center of a metal plate made of aluminum alloy (JIS H4000 "A5052"), which was shaped like a strip with dimensions of 45 mm in length, 12 mm in width, and 1.5 mm in thickness. The measurement range was 4.2 mm in the 45 mm length direction. The cutoff value λc was 0.8000 mm. The same operation was repeated 30 times at different locations, and the average value was calculated. The arithmetic mean roughness (Ra) was 58 μm, and the maximum height (Rz) was 228 μm. Surface and cross-sectional observation using an electron microscope (Hitachi High-Tech S3400) revealed an aperture diameter of 50-190 μm and a depth of 40-180 μm.

[0226]

Table 1

[0227]

Table 2

[0228] (Preparation of Polyester Resin Compositions α1 to 17) Among the components shown in Table 1, excluding the fibrous reinforcing filler (d), each component was uniformly mixed with a tumbler mixer at the ratios shown in Table 2 (all in parts by mass), and then a meshing co-rotating twin-screw extruder (manufactured by Japan Steel Works, Ltd., "TEX-30α", screw diameter 32 mm, L / D = 52) was used. The fibrous reinforcing filler (d) was supplied from a side feeder at 40 kg / hr. The barrel set temperatures C1 to C15 of the extruder were 260 °C, the die was 250 °C, and melt kneading was carried out under the conditions of a screw rotation speed of 200 rpm, a nozzle number of 4 holes (circular (φ4 mm), length 1.5 cm), and a shear rate (γ) of 211 sec ―1 under the conditions, and extruded as strands. The strand temperature immediately after extrusion was 270 °C. The extruded strands were introduced into a water bath adjusted to a temperature range of 30 to 50 °C and rapidly cooled. The strand surface temperature (T) was cooled to 65 °C at the temperature measured by an infrared thermometer (γ·T = 1.4×10 4 ), inserted into a pelletizer and cut to obtain pellets of polybutylene terephthalate-based resin compositions α1 to 17. Then, the obtained pellets of polyester resin compositions α1 to 17 were dried at 120 °C for 5 hours and then used for insert molding.

[0229] <Examples 1 to 22, Comparative Examples 1 to 15> The metal members X1, X2, and X3 (hereinafter collectively referred to as "X") prepared as described above were placed in the mold cavity, and the pellets of the polyester resin compositions α1 to α17 obtained above were injection molded under the conditions shown below to obtain a resin-metal composite (evaluation sample) in which the metal members (X) and the resin members (Y) made of the polyester resin composition (A) were joined together, as shown in Figure 5. At this time, the bonding area between the metal members (X) and the resin members (Y) was 5 mm × 10 mm. Injection molding conditions: A Japan Steel Works "J85AD" injection molding machine was used, with the following conditions: cylinder temperature 270°C, mold temperature 140°C, injection speed 60 mm / sec, filling time 0.2 seconds, holding pressure 110 MPa, holding pressure time 10 seconds, and cooling time 30 seconds.

[0230] <Evaluation and Measurement Methods> The resin-metal composites (evaluation samples) obtained in the examples and comparative examples were measured and evaluated using the following methods.

[0231] (Joining strength) Using the resin-metal composites (evaluation samples) obtained in the examples and comparative examples, the bonding strength was measured in accordance with ISO 19095 as follows. Using a tensile testing machine (Instron Model 5544), tensile tests (tensile speed 5 mm / min) were performed perpendicular to the joint surface at the end of the obtained resin-metal composite (evaluation sample) to measure the maximum tensile stress at the joint surface, i.e., the joint strength. The obtained strengths are recorded in the "Joint Strength" column of Tables 3-1 and 3-2.

[0232] (Tensile strength retention rate after 100 hours of PCT testing) Using the pellets of polyester resin compositions α1 to α17 obtained by the above method, the tensile strength retention rate after 100 hours of PCT testing was measured as follows. After drying the pellets at 120°C for 5 hours, ISO multipurpose test specimens (4 mm thick) were injection molded using an injection molding machine (NEX80, manufactured by Nissei Plastic Industrial Co., Ltd.) under the conditions of a cylinder temperature of 250°C and a mold temperature of 80°C. Using ISO multipurpose test specimens, the tensile strength (before treatment) was measured in accordance with ISO 527 at a tensile speed of 5 mm / min (unit: MPa). The ISO multipurpose test specimens were then treated for 100 hours using a pressure cooker (PCT) testing machine (Hirayama Seisakusho Co., Ltd.) under conditions of 121°C, 100% relative humidity, and 2 atm pressure. The tensile strength was measured similarly, and the strength retention rate after treatment compared to before treatment (unit: %) was calculated.

[0233] (Gas generation after 300 continuous molding shots) Using the pellets of polyester resin compositions α2, α4, and α7 obtained by the above method, a gas generation test was conducted by the following mold deposit evaluation.

[0234] [Mold deposit evaluation] The molding machine and conditions used for the evaluation are as follows: Injection molding machine, manufactured by Sumitomo Heavy Industries, Ltd., SE18. Injection pressure: 50 MPa, Injection speed: 80 mm / sec Cylinder temperature: 270℃ Injection time 3sec Cooling 8sec Mold temperature: 35℃ Sackback 3mm Molded product: Length 35mm, Width 14mm, Thickness 2mm Mold, Pin Gate Mold

[0235] Under the above conditions, injection molding was performed continuously for 300 shots. After this, the condition of the mold deposits adhering to the mold (mold contamination) was observed visually and evaluated on a scale of 1 to 10, with the best condition of the mold deposits receiving a score of 10. The evaluation results are shown in Tables 3-1 and 3-2 below.

[0236] (Evaluation of mold release properties during continuous molding) During the mold deposit evaluation test, 300 continuous molding shots were performed, and the release properties during continuous molding were evaluated according to the following criteria. The results are shown in Tables 3-1 and 3-2. ○(good): There was little adhesion to the mold during demolding, enabling continuous automatic molding. ×(poor): Frequent sticking to the mold during demolding made continuous automated molding difficult.

[0237] [Table 3-1]

[0238] [Table 3-2]

[0239] (Consideration) As is clear from the results above, Examples 1 to 22, where Ra / (Fd×Wr) is 0.5 or higher, showed improved bonding strength compared to Comparative Examples 1 to 15, where Ra / (Fd×Wr) was less than 0.5. Furthermore, comparing Examples 3, 6, and 9, it was found that using polyethylene oxide wax as the low molecular weight compound (c) reduced the amount of gas during continuous molding. Moreover, as shown in the results of Example 3, it was found that using low molecular weight compound c1, i.e., polyethylene oxide wax with a molecular weight of 4000 and an acid value of 1 mgKOH / g, further reduced the amount of gas.

[0240] <Examples 23-29> (Relative permittivity, dielectric loss tangent) The pellets of polybutylene terephthalate-based resin compositions α1 to α7 obtained by the method described above were dried at 120°C for 5 hours. Then, using a Nissei Plastic Industrial Co., Ltd. injection molding machine "NEX80-9E" at a cylinder temperature of 250°C and a mold temperature of 80°C, a flat molded body measuring 100 mm in length, 100 mm in width, and approximately 2 mm in thickness was obtained. The molded body obtained in this manner was placed on a sample stage with a diameter of Φ80 mm, and the transmission attenuation and phase shift were measured using the free-space frequency variation method under measurement conditions of 25°C and a measurement frequency of 70-90 GHz. This was done using a Virginia Diodes WR10-VNAX millimeter-wave module, a Keysight N5227A network analyzer, and a Keycom DPS10 millimeter-wave / microwave measurement system equipped with a Keycom dielectric lens transmission attenuation measurement jig. The precise thickness of the molded body was measured using a Shinwa digital micrometer, and the relative permittivity and dielectric loss tangent at 76.5 GHz were determined based on the above-mentioned transmission attenuation, phase shift, and thickness measurement results.

[0241] [Table 4]

[0242] (Consideration) The compositions of Examples 23 to 29 have a relative permittivity of around 3.4 to 3.6 and a dielectric loss tangent of around 0.01, indicating that they can be suitably used in automotive sensor components, radome components, ECU cases, millimeter-wave radar cases, and the like. [Explanation of symbols]

[0243] (X)...Metal parts (Y) ·· Resin component Y1...peripheral wall part (J)·Joint part (Z) Other parts

Claims

1. The device comprises a metal member (X) having a surface with surface irregularities and a resin member (Y) made of a thermoplastic resin composition (A), A resin-metal composite having a structure in which a metal member (X) with an uneven surface is joined to a resin member (Y), wherein the thermoplastic resin composition (A) includes a thermoplastic resin and a fibrous reinforcing filler, The thermoplastic resin includes polybutylene terephthalate, and the average fiber diameter (Fd) of the fibrous reinforcing filler is 4 to 9 μm. A resin-metal composite characterized by satisfying the following relation (1). 1.0 ≤ Ra / (Fd × Wr) ≤ 70 ... (1) (Note that in the above relational formula (1), Ra represents the arithmetic mean roughness (μm) of the surface of the metal member (X) measured in accordance with JIS B 0601:2001, Fd represents the average fiber diameter (μm) of the fibrous reinforcing filler, and Wr represents the amount (parts by mass) of the fibrous reinforcing filler in the thermoplastic resin composition (A) / the total amount (parts by mass) of all constituent components in the thermoplastic resin composition (A).)

2. The resin-metal composite according to claim 1, wherein the content of the thermoplastic resin is 30 to 80% by mass in the thermoplastic resin composition (A).

3. The thermoplastic resin composition (A) comprises a polyester (a-1) containing polybutylene terephthalate and a thermoplastic resin (a-2) that is compatible with the polyester (a-1). The metal-resin composite according to claim 1 or 2, comprising the polyester (a-1) and the thermoplastic resin (a-2) in a mass ratio of (a-1):(a-2) = 20:80 to 80:

20.

4. The resin-metal composite according to any one of claims 1 to 3, wherein the bonding strength between the metal member (X) and the resin member (Y), as measured in accordance with ISO 19095, is 26 MPa or more.

5. The resin-metal composite according to any one of claims 1 to 4, wherein the surface of the metal member (X) has an arithmetic mean roughness (Ra) of 0.01 to 100 μm, as measured in accordance with JIS B 0601:2001.

6. The resin-metal composite according to any one of claims 1 to 5, wherein the thermoplastic resin composition (A) contains a low molecular weight compound (c) having a number average molecular weight of 50 or more and less than 6000, and the low molecular weight compound (c) contains oxidized polyethylene wax.

7. The resin-metal composite according to any one of claims 1 to 6, wherein the thermoplastic resin composition (A) contains a low molecular weight compound (c) having a number average molecular weight of 50 or more and less than 6000, and the acid value of the low molecular weight compound (c) is 0.01 to 40 mg / KOH.

8. The resin-metal composite according to any one of claims 1 to 7, wherein the thermoplastic resin composition contains a low molecular weight compound (c) having a number average molecular weight of 50 or more and less than 6000, and the acid value of the low molecular weight compound (c) is 0.5 to 20 mg / KOH.

9. The resin-metal composite according to any one of claims 1 to 8, wherein the average fiber length of the fibrous reinforcing filler is 50 to 800 μm.

10. The resin-metal composite according to any one of claims 1 to 9, wherein the thermoplastic resin composition (A) further comprises an epoxy group-containing compound (b).

11. The resin-metal composite according to claim 3, wherein the thermoplastic resin (a-2) is polyethylene terephthalate.

12. The resin-metal composite according to any one of claims 1 to 11, wherein the resin member (Y) covers the peripheral edge on the front side of the metal member (X) having an uneven surface, from the peripheral edge on the front side through the side end surface to the peripheral edge on the back side, and the uneven portion of the metal member (X) and the thermoplastic resin composition of the resin member (Y) are joined at the peripheral edge on the front side and the peripheral edge on the back side of the metal member.

13. A method for producing a resin-metal composite according to any one of claims 1 to 12, comprising the step of applying a molten resin composition to a metal member (X) having irregularities on its surface by injection molding.

14. The method for manufacturing a resin-metal composite according to claim 13, wherein the surface irregularities of the metal member (X) are due to treatment with a chemical solution.

15. The method for manufacturing a resin-metal composite according to claim 13, wherein the surface irregularities of the metal member (X) are provided with a coating of a chemical solution as the outermost layer.

16. The method for manufacturing a resin-metal composite according to claim 13, wherein the surface irregularities of the metal member (X) are due to laser treatment.

17. A vehicle component comprising a resin-metal composite as described in any one of claims 1 to 12.

18. An electrical component comprising a resin-metal composite according to any one of claims 1 to 12.

19. A housing component made of a resin-metal composite according to any one of claims 1 to 12.

20. A component for a smartphone casing, comprising a metal-resin composite according to any one of claims 1 to 12.

21. A housing component for an electrical component for a vehicle, comprising a resin-metal composite according to any one of claims 1 to 12.

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