TWI630101B - Metal resin joint body and its manufacturing method - Google Patents

Abstract

The present invention provides a metal-resin bonded body that can exhibit excellent bonding strength without causing a decrease in strength after a durability test and can maintain excellent bonding strength for a long time.

The metal-resin bonded body of the present invention comprises a metal substrate, an oxygen-containing oxygen-containing film formed on the surface of the metal substrate by intentionally applying a treatment for increasing the oxygen content, and the oxygen-containing film A metal resin bonded body of a resin molded article formed from a thermoplastic resin composition having an additive compound having a specific functional group that reacts with an oxygen-containing film above, and the functional group of the aforementioned additive compound is selected from a carboxyl group and a salt thereof, and At least one of the group consisting of an ester, an epoxy group, an epoxy propyl group, an isocyanate group, a carbodiimide group, an amine group and a salt thereof, and an acid anhydride group and an ester thereof.

Description

Metal resin joint body and its manufacturing method

The present invention relates to a resin-molded body made of a metal base material made of metal and a thermoplastic resin. The injection-molding or thermocompression bonding of the thermoplastic resin can be used to firmly join the integrated metal-resin bonded body and a method for manufacturing the same.

In recent years, copper substrates composed of copper or copper alloys with very high heat dissipation or electrical conductivity have been widely used in various sensing parts of automobiles, household electrical parts, and industrial machine parts. Aluminium base materials composed of other metals, lightweight aluminum or aluminum alloys, are metal resin joined bodies integrated with resin moldings made of thermoplastic resins with high insulation performance, light weight, and low cost, and their uses are expanding.

In the past, metal substrates and resin molded bodies of such different materials were joined together to form a metal resin bonded body, which was used for bonding between the metal substrate and the resin molded body with an adhesive under pressure. However, nowadays, as the industrially preferred joining method, the following method has been developed: a metal substrate is embedded in a mold for injection molding, and a molten thermoplastic resin is injected onto the surface of the embedded metal substrate so as to be heated by heat. Plastic resin shot A method for joining a metal substrate and a resin molded body at the same time when forming a resin molded body is proposed, and a method for making the bonding between the metal substrate and the resin molded body cheaper and to improve the bonding strength is proposed. Several methods. Such proposals are mostly those who apply an appropriate surface treatment to the surface of a metal substrate.

For example, the present inventors have proposed an aluminum-resin injection-molded integrally molded product, which is characterized in that an aluminum-shaped body and a resin-molded body are embedded with each other by a recessed portion of an existing aluminum material and an embedded portion of a thermoplastic resin. (Patent Document 1), and also proposes an aluminum alloy member characterized by having a convex portion made of silicon crystal (Patent Document 2).

In addition, for example, it has been proposed that an aluminum alloy object obtained by pretreatment immersed in an aqueous solution selected from the group consisting of ammonia water, hydrazine, and a water-soluble amine compound, and a thermoplastic resin composition are injection molded. Technology (Patent Documents 3 and 4), and the use of an aqueous solution of triazine dithiophenols or a solution of various organic solvents as a solvent as a plating solution to perform a chemical surface treatment of the electrochemistry of a metal, and then the surface treatment Technology for joining metal to rubber or plastic (Patent Document 5), and technology for applying an adhesive on a metal plate or performing surface treatment to form an organic film, and then integrating the metal and resin by injection molding (Patent Document 6) A technique in which the surface of a metal is treated with an acid or an alkali, and then treated with a silane coupling agent, and then bonded to a resin by injection molding (Patent Document 7).

Furthermore, it is proposed that a thermoplastic resin is injected on the metal surface on which a film containing a microporous hydroxyl group is formed, and gold is transmitted through the film. It is a technology integrated with a thermoplastic resin (Patent Document 8), and a polyarylene sulfide resin is used as a main body, and a resin material mixed with a specific fluorene-based copolymer and an inorganic filler is used for metal terminals, etc. A technique of embedding and joining (Patent Document 9).

Patent Document 1: WO2009-151099

Patent Document 2: Japanese Patent Application Laid-Open No. 2010-174372

Patent Document 3: Japanese Patent No. 3954379

Patent Document 4: Japanese Patent No. 4270444

Patent Document 5: Japanese Patent Publication No. 05-051671

Patent Document 6: Japanese Patent No. 3016331

Patent Document 7: Japanese Patent Application Laid-Open No. 2003-103562

Patent Document 8: Japanese Patent Application Laid-Open No. 2003-162115

Patent Document 9: Japanese Patent Application Laid-Open No. 04-211916

Here, in the method using ammonia water, hydrazine, and water-soluble amine compounds described in Patent Documents 3 and 4, there is a limitation in the time from the treatment to the injection molding, so that the time for maintaining a stable surface state is short. problem. Further, the processing method described in Patent Document 5 has a problem of complicated processing, and the method described in Patent Document 6 or 7 has problems of complicated steps or high processing cost.

However, as described in Patent Document 1 or Patent Document 2, the present inventors have so far mainly proposed the physical bonding of the chimera based on the alignment effect, and the method thereof is based on the special Etching method. Although these methods have no problem in performance such as joint strength or air-tightness of the joint portion, they are caused by the etching process. The halogen gas does not corrode surrounding metal parts or devices, and it is necessary to propose countermeasures that do not pollute the surrounding environment, and other problems arise.

Further, Patent Document 8 describes the alignment effect and chemical action with a porous hydroxyl-containing film, and the effect of using a thermoplastic resin composition added with a thermoplastic elastomer is described in Patent Document 9 in a polyarylene sulfide. The resin mixes the adhesion of resin materials such as olefin-based copolymers with metals, but the effect on the bonding strength or adhesion caused by the combination of the metal surface treatment and the functional group of the resin composition is unknown.

Therefore, the present inventors have to develop a simple operation at a low cost and a long-term long-term operation for joining metal substrates and resin molded articles made of a thermoplastic resin without problems in surrounding equipment or the environment. As a result of diligent research on the method of excellent bonding strength, it was found that the surface of the metal substrate was intentionally treated by increasing the oxygen content to form an oxygen-containing oxygen film, and the oxygen-containing oxygen film was formed on the oxygen-containing oxygen film. When the thermoplastic resin composition joins the formed resin bodies, an additive compound having a specific functional group capable of reacting with an oxygen-containing film is added to the thermoplastic resin composition, so that between the metal substrate and the resin body In the case of injection molding and thermocompression bonding (metal-resin bonding), the present invention can be completed by forming a long-term and strong bond between the oxygen-containing film on the surface of the metal substrate and the resin molded body.

Therefore, an object of the present invention is to provide a metal resin bonded body, It can exhibit excellent metal-resin bonding strength while not causing a decrease in strength after the endurance test, and can maintain excellent metal-resin bonding strength for a long time.

That is, the present invention provides a metal-resin bonded body, which is characterized by having a metal substrate made of a metal and a content formed on the surface of the metal substrate by intentionally applying a treatment for increasing the oxygen content. An oxygen-containing film and a resin molded body formed of a thermoplastic resin composition bonded to the oxygen-containing film, the thermoplastic resin composition contains a functional group having a functional group capable of reacting with the oxygen-containing film. An additive compound having a group selected from the group consisting of a carboxyl group and a salt thereof and an ester thereof, an epoxy group, an epoxy propyl group, an isocyanate group, a carbodiimide group, an amine group and a salt thereof, and an acid anhydride group and an ester thereof; A functional group constituting at least one of the groups.

In addition, the present invention also provides a method for manufacturing a metal-resin bonded body, which comprises the steps of forming an oxygen-containing film on a surface of a metal substrate made of a metal by intentionally applying a treatment for increasing an oxygen content. The film forming step of the film forming step, and the resin forming step of forming a resin molded body by injection molding of a thermoplastic resin composition on the oxygen-containing film of the surface-treated metal substrate obtained in this film forming step, are A method for producing a metal-resin bonded body through which the metal substrate and the resin molded body are joined through the oxygen-containing film, wherein the thermoplastic resin composition contains Functional compound additive compound, the aforementioned additive compound has a compound selected from a carboxyl group and a salt thereof, an ester thereof, an epoxy group, an epoxy propyl group, an isocyanate group, a carbodiimide group, an amine group and a salt thereof, and an acid anhydride A functional group of at least one of the group consisting of a group and its ester.

Furthermore, the present invention also provides a method for manufacturing a metal-resin joint, which has the following steps: intentionally applying a treatment for increasing the oxygen content on the surface of a metal substrate made of a metal to form oxygen-containing A film forming step of a film, a resin forming step of forming a resin molded body by injection molding of a thermoplastic resin composition, and an oxygen-containing film of a surface-treated metal substrate obtained by the aforementioned film forming step, The resin-molded body obtained by the aforementioned resin-molding step is subjected to injection-molding or thermocompression bonding, which is a metal-resin bonding of a metal-resin bonded body through which the aforementioned oxygen-containing film is passed to manufacture a metal substrate and a resin-molded body. The manufacturing method of the body, the thermoplastic resin composition contains an additive compound having a functional group capable of reacting with an oxygen-containing film, and the additive compound has a compound selected from a carboxyl group and a salt thereof, an ester thereof, an epoxy group, and an epoxypropyl group. At least one member of the group consisting of isocyanate group, carbodiimide group, amine group and its salt, and acid anhydride group and its ester Energy base.

In the present invention, there are no particular restrictions on the metal substrate of the raw material, the copper substrate composed of copper or copper alloy, the iron substrate composed of iron or iron alloy, the aluminum substrate composed of aluminum or aluminum alloy, etc. It can be determined according to the use of the metal-resin joint formed by the use or various physical properties such as strength, corrosion resistance, and processability required for the use. The material or shape of the aluminum substrate It is not particularly limited as long as it is made of aluminum or an aluminum alloy, and can be determined according to various physical properties such as the use of the aluminum-resin joint formed by using it or the strength, corrosion resistance, and workability required for the use. .

Further, the oxygen-containing oxygen-containing film formed on the surface of the metal substrate in the film-forming step is not particularly limited as long as it has good adhesion to the metal substrate. When the metal substrate is copper-based For example, an oxygen-containing film obtained by blackening treatment, an oxygen-containing film (thermal oxidation film) obtained by laser treatment, and, for example, when the metal substrate is an iron substrate, for example, galvanizing treatment may be used. The obtained oxygen-containing film derived from the zinc film and the like, and when the metal substrate is an aluminum substrate, for example, a zinc-containing zinc-containing film obtained by a film-forming treatment using an alkaline aqueous solution containing zinc ions, or the Film formation treatment of hot water of 91 ° C to 100 ° C, or water and oxide film obtained from film formation treatment of warm water of 60 ° C to 90 ° C, or laser treatment on the surface of an aluminum substrate An oxide film or the like obtained by a film formation process.

Here, as for the film formation treatment for forming a zinc-containing zinc-containing film as an oxygen-containing film on the surface of an aluminum substrate, as long as zinc oxide and zinc oxide (ZnO) and zinc oxide can be formed on the surface of the aluminum substrate together with the zinc element. Films contained in the form of iron (ZnFeO), zinc aluminum oxide (ZnAlO), etc. may be used. When the resin molded body is formed by injection molding of a thermoplastic resin composition or the like, or by using the thermoplastic resin composition The thermocompression bonding of the formed resin molded body and the resin molded body formed on the oxygen-containing film can achieve a strong aluminum-resin bonding strength.

For the film formation treatment using the zinc-containing alkaline aqueous solution, it is preferred to use a ratio of 1 to 100 by weight (MOH / Zn ²⁺ ), preferably a ratio of 2 to 20, and more preferably 3 or more. A zinc-containing alkali aqueous solution containing alkali hydroxide (MOH) and zinc ions (Zn ²⁺ ) in a ratio of 10 or less, and the zinc-containing alkali aqueous solution is brought into contact with the surface of an aluminum substrate at normal temperature, so that the aluminum substrate A zinc-containing film containing oxygen is formed on the surface. If the weight ratio (MOH / Zn ²⁺ ) of the alkali hydroxide (MOH) to zinc ions (Zn ²⁺ ) is less than 1 (MOH <Zn ²⁺ ), zinc cannot be fully dissolved and its effect cannot be fully exerted. On the contrary If it is greater than 100 (MOH> Zn ²⁺ ), the dissolution of the aluminum substrate is faster than the substitution and precipitation of zinc, making it difficult for zinc to precipitate onto the surface of the aluminum substrate.

Here, as the alkali source in the alkali aqueous solution containing zinc ions, it is preferable to use any one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide. The zinc ion source is preferably any one or more selected from the group consisting of zinc oxide, zinc hydroxide, zinc peroxide, zinc chloride, zinc sulfate, and zinc nitrate.

In the alkaline aqueous solution containing zinc ions, the concentration of potassium hydroxide is preferably 10 g / L or more and 1000 g / L or less, preferably 50 g / L or more and 300 g / L or less, and the zinc ion concentration is 1 g It is preferably at least 200 g / L, preferably at least 10 g / L and at most 100 g / L. When the composition of the alkaline aqueous solution containing zinc ions is within the above range, a substitution reaction between aluminum and zinc ions occurs on the surface of the aluminum substrate, the aluminum dissolves, and zinc ions are precipitated as fine particles. As a result, the aluminum substrate An oxygen-containing film (zinc-containing film) containing oxygen and zinc elements is formed on the surface. That is, aluminum is dissolved while forming a recessed portion, and zinc precipitates in the recessed portion to form a zinc-containing film containing zinc. Here, when the alkali hydroxide concentration is less than 10 g / L, there will be zinc containing zinc. The problem of insufficient film formation. On the contrary, if it exceeds 1000 g / L, the dissolution rate of aluminum due to alkali is high, and a problem that a zinc-containing film containing zinc cannot be formed occurs. In addition, when the zinc ion concentration is less than 1 g / L, there is a problem that it takes time to form a zinc-containing film. Conversely, if it exceeds 200 g / L, the zinc deposition rate cannot be controlled and a non-uniform surface occurs.

Moreover, regarding the film formation process for forming water and an oxide film as an oxygen-containing film on the surface of an aluminum substrate, first, a conductivity of 0.01 mS / m or more and 20 mS / m or less, preferably 0.01 mS / m or more, is used. 10mS / m or less of 91 ° C to 100 ° C hot water, immersing the aluminum substrate in the hot water is generally 0.5 minutes to 30 minutes, preferably 1 minute to 10 minutes to form water and oxides Or, use warm water having a conductivity of 0.01 mS / m or more and 20 mS / m or less, preferably 0.01 mS / m or more and 10 mS / m or less, at 60 ° C to 90 ° C, and immerse the aluminum substrate in the warm water It is generally 0.5 minutes to 30 minutes, preferably 1 minute to 10 minutes to form water and oxides. The hot water or warm water used for the film formation treatment for forming the water and oxide film is preferably pure water. If the conductivity of the hot water or warm water used to form the film forming process of this water and oxide film is less than 0.01mS / m, it is in the range of ultrapure water, so the production cost of pure water is too high and It is difficult to put it into practical use or industrialization. Conversely, if it exceeds 20 mS / m, water and oxide films cannot be formed, and the film formation rate is extremely slow. Moreover, the defects of water and film are liable to occur due to the presence of impurities. .

The water and oxide film formed on the surface of the aluminum substrate were confirmed by X-ray diffraction. The film formation process was not confirmed to confirm the presence of a broad wave film with boehmite or pseudoboehmite as the main body, and the film formation process using warm water of 60 ° C to 90 ° C was not confirmed. The peak derived from the crystalline component is mainly an amorphous film.

In addition, the X-ray diffraction measurement of water and oxide film was made by forming a surface-treated aluminum substrate on the surface of the aluminum substrate treated with the film to form an oxygen-containing film of water and an oxide film. A measurement sample of 30 mm × 30 mm was prepared, and the sample was fixed to a glass sample plate (sample portion 24 mm angle and penetration) of an X-ray diffraction device [manufactured by Rigaku Corporation: RAD-rR]. X-ray source: Cu rotating counter-cathode target (using X-ray and wavelength: CuKα 1.5418Å), X-ray output: 50kV, 200mA, detector: flicker detector, optical system attributes: Bragg-Brentano optical system (concentration method), divergence Measured under conditions of a slit of 1 °, a scattering slit of 1 °, and a light-receiving slit of 0.3 mm. The components were identified. Then, among the peaks representing the respective phases, the peaks of high intensity do not overlap with the peaks of other components. The peak of 1 is calculated by integrating the integral diffraction intensity.

Furthermore, as for the laser treatment performed on the surface of the aluminum substrate to form an oxide film as an oxygen-containing film on the surface of the aluminum substrate, as long as the portion near the surface of the aluminum substrate, and preferably only near the surface, can be processed It can be heated above the melting temperature of the aluminum substrate to oxidize it, so that alumina (Al ₂ O ₃ ) is precipitated near the surface of the aluminum substrate to form an oxygen-containing film containing the alumina (Al ₂ O ₃ ). For example, it can be performed using a laser etching apparatus or the like.

In this way, in the film formation step described above, oxygen-containing material is formed on the surface of the aluminum substrate. The surface-treated aluminum substrate obtained from the film has an oxygen content of 0.1 to 50% by weight, preferably 1.0 to 30% by weight, as measured by EPMA in the surface layer from the outermost surface to a depth of 3 μm. 30 % By weight or less. If the oxygen content in the surface layer of the surface-treated aluminum substrate is less than 0.1% by weight, the film will be too thin and it will be difficult to achieve sufficient aluminum-resin bonding strength between the aluminum substrate and the resin molded body. Conversely, if the oxygen content is as high as more than 50% by weight, the film will be too thick to cause aggregation and destruction of the film, and sufficient aluminum-resin bonding strength cannot be obtained.

The film thickness of the oxygen-containing film formed on the surface of the aluminum substrate in the film formation step is usually preferably 0.06 μm or more and 2 μm or less, and more preferably 0.1 μm or more and 1 μm or less. If the thickness of this oxygen-containing film is less than 0.06 μm, the film is too thin to obtain sufficient aluminum-resin bonding strength. Conversely, if it exceeds 2 μm, the film is too thick to cause the film to agglomerate and fail to obtain sufficient thickness. Al-resin bonding strength.

The thickness of the water and oxide film formed on the surface of the aluminum substrate using a film formation treatment using hot water of 91 ° C to 100 ° C is usually 0.1 μm to 1 μm, and more preferably 0.2 μm to 0.5 μm. . If the film thickness of the water and oxide film is less than 0.1 μm, the film is too thin to obtain sufficient aluminum-resin bonding strength. Conversely, if it exceeds 1 μm, the film is too thick, causing the film to agglomerate and break. A sufficient aluminum-resin bonding strength cannot be obtained.

In addition, the thickness of the water and oxide film formed on the surface of the aluminum substrate by the film formation treatment using warm water of 60 ° C. to 90 ° C. is usually preferably 0.1 μm to 1 μm, and more preferably 0.2 μm to 0.5 μm. To under. If the film thickness of the oxygen-containing film is less than 0.1 μm, the film is too thin to obtain sufficient aluminum-resin bonding strength. Conversely, when the film thickness is more than 1 μm, the film is too thick, causing the film to agglomerate and fail to obtain the film. Full aluminum-resin bonding strength.

In the present invention, the surface-treated aluminum substrate having an oxygen-containing film on the surface obtained in the above-mentioned film-forming step is composed of a thermoplastic resin formed on the oxygen-containing film by injection molding to connect the resin molded body. An integrated resin molding step to produce an aluminum resin bonded body, or a resin molding step of forming a resin molded body by injection molding of a thermoplastic resin composition, and a surface-treated aluminum substrate with the obtained resin molded body The oxygen-containing film is combined with aluminum resin bonding by thermal compression bonding using laser welding, vibration welding, ultrasonic welding, thermal compression welding, hot plate welding, non-contact hot plate welding, or high frequency welding. Steps to produce an aluminum resin bonded body.

In the present invention, the thermoplastic resin composition used in the resin molding step may specifically include, for example, polyarylene sulfide-based resins such as polyphenylene sulfide (PPS) or fluorene-based resins. Elemental resins, such as polyester resins such as polybutylene terephthalate (PBT), liquid crystal polymers, polycarbonate resins, polyacetal resins, polyether resins, polydiphenyl ether resins, etc. Oxygen-containing resins, such as resin compositions composed of nitrogen atom-containing thermoplastic resins such as polyamide (PA), ABS, polyimide, polyetherimide, etc. From the viewpoint of heat resistance and rigidity of automobile parts with large demand, and from the viewpoint of rigidity of motors and electronic parts, PPS, PBT, liquid crystal polymer, polycondensation Engineering plastics such as aldehyde are particularly good.

The thermoplastic resin composition used in the resin forming step is a resin composition containing an additive compound having a specific functional group capable of reacting with an oxygen-containing film. Here, the aforementioned additive compound may be any substance other than the thermoplastic resin constituting the thermoplastic resin composition, and may be any user that can be added to the thermoplastic resin composition, and is not particularly limited, and may be considered. The thermoplastic resin composition is manufactured, the moldability and processability of the thermoplastic resin composition, the characteristics of the resin molded body obtained by molding the thermoplastic resin composition, and the like are added for various purposes, and examples thereof include antioxidants and release agents. , Plasticizers, ultraviolet absorbers, heat stabilizers, antistatic agents, dyes, pigments, lubricants, silane coupling agents, fillers, elastomers and other additives, among them, the metal and resin produced by the relaxation of linear expansion difference From the viewpoint of strain, an elastomer is particularly preferred as an additive.

Here, the aforementioned additive compound may be selected from the group consisting of a carboxyl group and a salt thereof, an ester thereof, an epoxy group, an epoxy propyl group, an isocyanate group, a carbodiimide group, an amine group and a salt thereof, and an acid anhydride group and a A compound having at least one functional group in the ester group may be used, and among them, a compound having an epoxy group is particularly preferred. The additive compound is preferably an olefin-based copolymer containing a constituent unit derived from an α-olefin and a constituent unit derived from an propylene oxide derived from an α, β-unsaturated acid. ) An olefin-based copolymer as a constituent unit of an acrylate. Hereinafter, the (meth) acrylate is also referred to as a (meth) acrylate. For example, glycidyl (meth) acrylate is also referred to as glycidyl (meth) acrylate. In this specification, "(甲 "Base" acrylic acid means both acrylic acid and methacrylic acid, and "(meth) acrylate" means both acrylic acid and methacrylic acid.

The α-olefin is not particularly limited, and examples thereof include ethylene, propylene, and butene, and ethylene is particularly preferred. The α-olefin may be used singly or in combination of two or more kinds.

When the additive compound contains a constituent unit derived from an α-olefin, flexibility can be easily imparted to the resin molded body. By providing this flexibility, the resin molded body is softened, exhibits excellent metal-resin bonding strength, and prevents a decrease in strength after the endurance test, and it is easy to maintain excellent metal-resin bonding strength for a long period of time.

The propylene oxide of α, β-unsaturated acid is not particularly limited, and examples thereof include propylene acrylate, propylene methacrylate, and propylene acrylate. Oxypropyl esters are preferred. The propylene oxide of α, β-unsaturated acid may be used singly or in combination of two or more kinds. When the aforementioned additive compound contains propylene oxide of an α, β-unsaturated acid, the effect of improving the bonding strength between the metal and the resin can be obtained.

The (meth) acrylate is not particularly limited, and examples thereof include acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, n-hexyl acrylate, and n-octyl acrylate; Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, n-methacrylate Methacrylate such as octyl ester. Among them, methyl acrylate is particularly preferred. (Meth) acrylate, available separately Use 1 type, or you can use 2 or more types together. The constituent unit derived from (meth) acrylate contributes to the improvement of the bonding strength between metal and resin.

An olefin-based copolymer containing a constituent unit derived from an α-olefin and a constituent unit derived from an propylene oxide of an α, β-unsaturated acid, and an olefin-based copolymer further containing a constituent unit derived from a (meth) acrylate, It can be produced by polymerization in a conventional manner. For example, the above copolymer can be obtained by copolymerization by a generally known radical polymerization reaction. The type of the copolymer is not particularly limited, and may be, for example, a random copolymer or a block copolymer. The olefin-based copolymer may be chemically bonded in a branched or cross-linked structure such as polymethyl methacrylate, polyethyl methacrylate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, Polyethylene 2-hexyl acrylate, polystyrene, polyacrylonitrile nitrile, polyacrylonitrile nitrile · styrene copolymer, butyl acrylate · styrene copolymer, and other olefin-based graft copolymers.

The olefin-based copolymer used in the present invention may contain constituent units derived from other copolymer components as long as the effects of the present invention are not impaired.

The functional group of the aforementioned additive compound is contained in the thermoplastic resin composition at a ratio of 0.5 to 150 μmol / g, preferably 0.5 to 50 μmol / g, and more preferably 2 to 25 μmol / g. If the ratio of the functional groups in the thermoplastic resin composition is less than 0.5 μmol / g, the bonding strength between the metal and the resin is liable to decrease. Conversely, if it is higher than 150 μmol / g, it is easy to affect the characteristics of the resin material, especially Mechanical properties such as fluidity, tensile strength, and flexural strength, as well as rigidity, are not good because they are adversely affected.

Here, the proportion of the functional groups in the thermoplastic resin composition should be regarded as "per 10,000" of the additive compounds added to the thermoplastic resin composition. When the molecular weight of one functional group is M, the amount of functional groups in this additive compound is 1 / M (mol / g). Therefore, if the additive compound is added to the thermoplastic resin composition, for example, in a proportion of 1% by mass , It is calculated as (1 / M) × (1/100) = 1 / 100M (mol / g). Moreover, the aforementioned “molecular weight per functional group” M, when the additive compound has a plurality, for example, 2 functional groups , It is 1/2 of the molecular weight Mw of the additive compound itself.

In addition, in the present invention, an oxygen-containing film is formed on the entire surface of the metal substrate of the raw material, and the resin can be formed by injection molding only at a necessary portion of the obtained surface-treated metal substrate, or by thermocompression bonding. It is also possible to form an oxygen-containing film only on a part of a surface of a metal substrate or a necessary portion in consideration of cost, and to mold the necessary portion of the obtained surface-treated metal substrate by injection molding, or Thermocompression bonding joins the resin molded body. When the oxygen-containing film is formed only on a part of the surface of the metal substrate or a necessary part, a portion other than the portion where the oxygen-containing film is formed may be treated with a masking tape or the like to form an oxygen-containing film. , And then remove the masking tape, etc. of this mask part.

In addition to the above-mentioned film-forming step for forming an oxygen-containing film, the method for producing a metal-resin bonded body in the present invention may be selected from a degreasing treatment, an etching treatment, and a decontamination treatment as a pretreatment of the surface of the metal substrate, if necessary. , Roughening treatment, chemical polishing treatment, and electrolytic polishing treatment.

The degreasing treatment performed as the pretreatment can be performed using a general degreasing bath composed of sodium hydroxide, sodium carbonate, sodium phosphate, a surfactant, and the like. The treatment conditions are usually an immersion temperature of 15 ° C or higher. 55 ° C or lower, preferably 25 ° C or higher and 40 ° C or lower, and the immersion time is 1 minute to 10 minutes, preferably 3 minutes to 6 minutes.

In addition, as for the etching treatment performed as the pretreatment, an alkaline aqueous solution such as sodium hydroxide or an acid aqueous solution such as a sulfuric acid-phosphoric acid mixed aqueous solution is usually used. When using an alkaline aqueous solution, a concentration of 20 g / L or more and 200 g / L or less, preferably 50 g / L or more and 150 g / L or less, and an immersion temperature of 30 ° C. or higher and 70 ° C. or lower, preferably 40 ° C. or higher 60 The immersion treatment is performed under the conditions of a temperature of not more than 0 ° C and a treatment time of 0.5 minutes to 5 minutes, preferably 1 minute to 3 minutes. When a sulfuric acid-phosphoric acid mixed aqueous solution of an acid aqueous solution is used, a sulfuric acid concentration of 10 g / L or more and 500 g / L or less, preferably 30 g / L or more and 300 g / L or less, and a phosphoric acid concentration of 10 g / L or more and 200 g / L can be used. Below, preferably 30 g / L or more and 500 g / L or less, the immersion temperature is 30 ° C or higher and 110 ° C or lower, preferably 55 ° C or higher and 75 ° C or lower, and the immersion time is 0.5 minutes or longer and 15 minutes or lower, preferably The immersion treatment is performed under the treatment conditions of 1 minute to 6 minutes.

Furthermore, regarding the above-mentioned decontamination treatment performed as the pretreatment, for example, a decontamination bath composed of a 1-30% strength deacidified aqueous solution can be used, and the immersion temperature is preferably 15 ° C or higher and 55 ° C or lower, preferably The immersion treatment is performed under the treatment conditions of 25 ° C. to 40 ° C. and immersion time of 1 minute to 10 minutes, preferably 3 minutes to 6 minutes.

In addition, the roughening treatment performed as the pretreatment mentioned above can be exemplified by immersion in a treatment liquid containing acidic ammonium fluoride as a main component (trade name of Japan CB Chemical Co., Ltd .: JCB) after the pretreatment of the aluminum substrate. -3712) in the square Law, etc. By this treatment, even for the Al material containing Si in the alloy, Si can be removed without being dissolved. Therefore, even if an oxygen-containing film is attached, problems such as defects do not occur, and good bonding strength can be obtained.

In addition, as the chemical polishing or electrolytic polishing treatment performed in the pretreatment, a conventional method can be adopted.

Although the principle of bonding between the metal substrate and the resin molded body in the present invention is still unclear, after the metal substrate and the resin molded body are bonded, the oxygen-containing film formed on the surface of the metal substrate may not be covered. The destruction remains, and the following verification results can be estimated as follows.

For example, when the metal is an aluminum substrate, a plurality of surface-treated aluminum substrates having an oxygen-containing film on the surface of the aluminum substrate are formed. For a part of the surface-treated aluminum substrates, a ring is formed on the surface thereof. Injection molding of oxypropyl polyphenylene sulfide (PPS) joins PPS to form an aluminum PPS joint. In addition, for the remaining surface-treated aluminum substrate, first, stearic acid was volatilized in an electric furnace maintained at 100 ° C, and the surface-treated aluminum substrate was exposed to it for 24 hours to prepare an oxygen-containing film. Stearic acid-treated aluminum substrate of stearic acid monomolecular film, and on the surface of the stearic acid-treated aluminum substrate, PPS is bonded by injection molding of PPS with epoxypropyl group to make stearin. Acid-treated aluminum PPS joint.

As a result of measuring the difference in bonding strength between these aluminum PPS joints and stearic acid-treated aluminum PPS joints, the bonding strength in the stearic acid-treated aluminum PPS joints was compared with that of the aluminum PPS joints. Clearly reduced.

Stearic acid has the properties of having a hydrophilic carboxyl group (COOH) and a hydrophobic group alkyl group (C ₁₇ H ₃₅ ), and forming a single-molecule film having a thickness of 1 molecule. In stearic acid-treated aluminum PPS joints, the oxygen-containing film of this aluminum substrate and the carboxyl side of stearic acid are chemically bonded to form a shape in which the alkyl side is in contact with the PPS molded body. As a result, aluminum-based materials are hindered. It is estimated that the bonding strength between the material and the PPS molded body is lower than that of the aluminum PPS bonded body.

In addition, regarding the surface-treated aluminum substrate before and after stearic acid treatment, the surface of the aluminum substrate was observed for comparison, but no difference in the surface structure caused by the presence or absence of the stearic acid monomolecular film was observed. On the other hand, regarding the surface-treated aluminum substrate after the stearic acid treatment, when the droplet was dropped and the contact angle was measured, the contact angle was close to 180 °, and the droplet was approximately spherical. This is a result of stabilizing the alkyl side of the stearic acid on the outermost surface side of the aluminum substrate.

From the above, it can be known that a chemical bond is generated between the surface-treated metal substrate in the metal-resin bonded body of the present invention and the resin molded body having an epoxy group, and between the oxygen of the oxygen-containing film and the epoxy group in the resin It is presumed that the effect of improving the bonding strength between the metal substrate and the resin molded body is exerted by the chemical bonding effect.

The metal-resin bonded body of the present invention is formed by coating the surface of a metal base material with an oxygen-containing oxygen-containing film formed by intentionally applying a treatment for increasing the oxygen content. In addition, it is used as a thermoplastic composition. A resin composition of an additive compound having a specific functional group that can react with an oxygen-containing film is formed by injection molding of the thermoplastic resin composition, or If the resin molded body obtained by injection molding of this thermoplastic resin composition is thermocompression bonded, and the resin molded body can be joined on the oxygen-containing film on the surface of the metal substrate, the metal substrate can not only be passed through the oxygen-containing film Those that are strongly bonded to the resin molded body and can maintain excellent metal-resin bonding strength for a long period of time.

In addition, according to the method for producing a metal-resin bonded body of the present invention, the surface of the metal substrate is subjected to a process of intentionally increasing the oxygen content to form an oxygen-containing film. In addition, it can be operated at normal temperature, and there is no problem in the surrounding equipment and environment. It can be manufactured with simple operation and low cost, and can produce a metal-resin bonded body that can exhibit excellent bonding strength between metal and resin for a long time.

1‧‧‧ aluminum resin joint

2‧‧‧ Surface-treated aluminum substrate

3‧‧‧PPS molded body (resin molded body)

4‧‧‧ front joint

5‧‧‧ pin point gate

6‧‧‧tool

7‧‧‧Load

FIG. 1 is an explanatory diagram for explaining a metal-resin joint produced in Example 1 of the present invention.

FIG. 2 is an explanatory diagram for explaining a test method for evaluating a joint strength between a metal and a resin implemented in Example 1 of the present invention.

Hereinafter, the metal-resin bonded body of this invention and its manufacturing method are demonstrated concretely based on an Example and a comparative example.

1. In the following examples and comparative examples, the roughening treatment performed as the pretreatment and the film formation treatment for forming an oxygen-containing film are as follows.

[Roughening treatment]

First, as a pretreatment, an aluminum substrate was immersed in a nitric acid aqueous solution adjusted to 30% by mass at room temperature for 0.5 minutes, and then immersed in hydrogen adjusted to 5% by mass at 50 ° C for 0.5 minutes. The sodium oxide aqueous solution was immersed in a nitric acid aqueous solution adjusted to 30% by mass under the conditions of room temperature and 0.5 minutes, and then the pretreated aluminum substrate was immersed in the temperature of 40 ° C and 10 minutes. A roughened aluminum substrate was prepared from a treatment liquid (Japanese CB Chemical Co., Ltd .: JCB-3712) containing acidic ammonium fluoride as a main component whose concentration was adjusted to 20% by mass.

[Film formation treatment of oxygen-containing film] (1) Treatment method A (formation of zinc-containing film)

A zinc ion-containing sodium aqueous solution (NaOH-Zn ²⁺ solution) having a sodium hydroxide concentration of 100 g / L and a zinc oxide concentration of 25 g / L (20 g / L as Zn ²⁺ ) was prepared as a film-forming treatment agent. Next, the aluminum substrate was immersed in the aqueous sodium ion solution containing zinc ions at room temperature for 1 minute (Note: only 5 minutes of immersion was performed in Comparative Example 1), and then washed with water to prepare a surface containing Surface-treated aluminum substrate for testing of zinc-containing zinc-containing films of oxygen film.

(2) Treatment method B (water formation by hot water and oxide film)

The aluminum base material is immersed in hot water (pure water) at 91 to 100 ° C for 0.5 to 30 minutes, and is prepared with gibbsite as an oxygen-containing film formed on the surface. Or boehmite-based surface-treated aluminum substrate for testing water and oxide films.

(3) Treatment method C (the formation of water and oxide film by hot water)

Except for using warm water (pure water) with a temperature of 60 to 80 ° C and changing the immersion time to 1 to 5 minutes, it is made on aluminum substrate in the same way as treatment method B (the formation of water and oxide film by hot water). The surface of the material is formed with a surface-treated aluminum substrate for testing the water and oxide film mainly composed of amorphous components as an oxygen-containing film.

(4) Treatment method D (the formation of water and oxide film by laser treatment)

In the laser etching process (device name: Miyaji Technology / ML-7112A; laser light wavelength: 1064nm, aperture: 50 ~ 60μm, vibration mode: Q-switched wave, frequency: 10kHz), the surface of the aluminum substrate Laser irradiation was performed at a pitch width of 50 μm in the same direction, and a surface-treated aluminum substrate was formed on the surface of the aluminum substrate to form an oxide film (Al ₂ O ₃ ) as an oxygen-containing film.

2. In the following examples and comparative examples, the resin types and additive compounds in the resin composition used are as follows.

[Type of resin in resin composition]

PPS (1): PPS-based resin composition [trade name: Durafide (registered trademark) RSF-10719, made of polyplastics (stock); containing additive compounds a and b described later, and inorganic filler 50% described later].

PPS (2): PPS resin [(share) Kureha product name: Fortron KPS W203A {melt viscosity: 30Pa‧s (shear speed: 1216sec ^-1 , 310 ° C)}]

PBT: PBT resin [WinTech Polymer (trade name) TRB-CP]

PP: PP-based resin composition [(share) Product made by Prime Polymer: R-350G]

POM: POM resin [Make three Polyacetal copolymer obtained by copolymerizing 96.7% by mass with 3.3% by mass of 1,3-dioxane, melt index (measured at 190 ° C, load 2160g): 9g / 10min]

LCP: aromatic polyester liquid crystal resin [melting point: 280 ° C, melt viscosity (300 ° C): 50.1Pa‧s]

The above-mentioned aromatic polyester liquid crystal resin (LCP) was manufactured as follows.

A reactor equipped with a stirrer, a distillation tube, a gas introduction tube, and a discharge hole was used to fill the reactor with 345 parts by weight (73 mol%) of p-hydroxybenzoic acid and 175 parts by weight (27 mol%) of 6-hydroxy-2-naphthoic acid. , 0.02 parts by weight of potassium acetate, and 350 parts by weight of acetic anhydride. After the reactor was sufficiently replaced with nitrogen, the temperature was increased to 150 ° C. under normal pressure, and stirring was started. The mixture was stirred at 150 ° C for 30 minutes, and the temperature was gradually increased to distill off by-product acetic acid. When the temperature reaches 300 ° C, the inside of the reactor is gradually depressurized, and stirring is continued for 1 hour at a pressure of 5 Torr (that is, 665Pa). At the time when the target stirring torque is reached, the discharge hole at the lower part of the reactor is opened, and nitrogen is used. The resulting resin was extruded into a strand shape and taken out. The removed strands are granulated The machine is shaped into particles.

[Additive compounds in resin composition]

Additive compound a: Glycidyl-containing elastomer [Nippon Oil Co., Ltd. trade name: Modiper A4300]

Additive Compound b: Elastomers without functional groups [Dawu Chemical Pharmaceutical Co., Ltd. product name: Engage 8440]

Additive compound c: Glycidyl-containing elastomer [Product name: Sumitomo Chemical Co., Ltd .: BONDFAST 7L]

Additive compound d: Isocyanate compound [Degussa Japan (trade name): Vestanat T1890 / 100]

Additive compound e: epoxy-based compound [Mitsubishi Chemical Corporation's product name: Epikote JER1004K]

Additive compound f: Ester-based elastomer [trade name: NUC-6570, manufactured by Unicar (Japan)]

Additive compound g: dicyandiamine [trade name of Carbide Industries (Japan): dicyandiamine G]

Additive compound h: carbodiimide compound [Rhein Chemie Japan (stock) trade name: Starbucks Solu P400]

Additive compound i: Glycidyl-containing elastomer [Product name: Sumitomo Chemical Co., Ltd .: BONDFAST E]

3. In the following examples and comparative examples, the "oxygen content" and "film thickness" of the oxygen-containing film formed on the surface of the aluminum substrate and the "film thickness of the aluminum resin joint" were measured as follows. .

[Determination of oxygen content of oxygen-containing film]

For the surface-treated aluminum substrate obtained in the manufacturing process of the aluminum resin bonded body, EPMA (made by Shimadzu: EPMA1610) was used, and the irradiation diameter was 40 μm / step, and corresponding analysis was performed at 512 steps in the vertical and horizontal directions. Here, the measurement area is 20.48 mm × 20.48 mm, the sampling time for 1 step is 20 ms, the acceleration voltage is 15 kV, and the decomposition energy in the depth direction of oxygen is 3 μm or less. Next, the weight percentage (wt%) of the detected oxygen intensity was calculated from the calibration line prepared beforehand. The calibration curve was calculated by using two points of the oxygen strength of the Al ₂ O ₃ standard sample (oxygen content rate: 48 wt%) and the oxygen strength of the high-purity Al foil.

[Determination of film thickness of oxygen-containing film]

For the aluminum resin bonded body and the surface-treated aluminum substrate obtained from the manufacturing process of the aluminum resin bonded body, a focused ion beam processing device (FEI company: Quanta 3D type) was used to align the focused ion beam to the test. The sample surface was made to fly by the atomic bomb on the surface to take out the observation site, and processed into a thin film with a thickness of about 100 nm to make an observation sample. The observation was performed using a transmission electron microscope (TEM) (manufactured by FEI: Tecnnai G2 F20 S-TWIN) at an acceleration voltage of 200 kV.

[Example 1] (1) Production of surface treated aluminum substrate

Cut from commercially available aluminum sheet (A5052; plate thickness 2.0mm) 50mm × 25m aluminum substrate. Next, by the above-mentioned treatment method A (formation of a zinc-containing film), a test-treated aluminum substrate having an oxygen-containing film containing zinc formed on the surface was prepared.

The obtained surface-treated aluminum substrate was subjected to an oxygen content measurement, an oxygen intensity measurement, and a film thickness measurement.

The results are shown in Table 1.

(2) Resin composition

As the thermoplastic resin composition, the additive compound a and the additive compound b shown in Table 1 and a PPS-based resin composition [PPS (1)] with 50% of the inorganic filler were used. This PPS-based resin composition [PPS (1)] is a resin composition having a melt viscosity of 230 Pa · s (310 ° C, 1000 s ^-1 ).

(3) Production of aluminum resin joints

After the resin composition obtained above is introduced into an injection molding machine, it is installed in a mold of a surface-treated aluminum substrate injection molding machine for testing, at a mold temperature of 160 ° C, a cylinder temperature of 320 ° C, an injection speed of 70mm / s, The injection molding conditions at a holding pressure of 80 MPa and a holding pressure time of 5 seconds were used to perform injection molding of the resin to produce an aluminum-resin bonded body 1 for testing as shown in FIG. 1.

The aluminum resin bonded body 1 is a surface-treated aluminum base material 2 having a thickness of 2 mm, and has a front end bonding portion 4 having a size of 5 mm × 5 mm × 10 mm at the front end, and an aluminum resin having a thickness of 4 mm other than the front end bonding portion 4. The joint body 1 is joined to the front-end joint portion 4 so that the joint body 1 has a joint area of 50 mm ^2. A 1.5 mm Φ pinpoint gate 5 is formed on the front-end joint portion 4.

[Evaluation test of bonding strength of aluminum resin bonded body]

With respect to this aluminum-resin bonded body 1, an evaluation test of the bonding strength between this aluminum-resin was performed by the following method.

As shown in FIG. 2, the surface-treated aluminum base material 2 of the aluminum resin bonded body 1 is fixed to a metal mold 6, and a load 7 is applied from the top of the PPS molded body 3 at a speed of 1 mm / min to implement a warping process. Test of the joint between the surface-treated aluminum substrate 2 and the resin molded body 3. Then, the resin agglomeration failure rate was judged visually on the aluminum side of the fracture surface.

The results are shown in Table 1.

[Examples 2 to 47]

The film formation treatment of the aluminum substrate, the oxygen-containing film, the oxygen-containing film, the resin composition, and the resin molding conditions were as shown in Tables 1 to 8, respectively, and the joint strength test was performed in the same manner as in Example 1.

In Example 29, a 30 wt% HNO ₃ solution was used. In Example 30, the conductivity of hot water was adjusted to the values shown in Table 5 using 0.1M NaOH.

In addition, in Examples 3, 4, 12 to 14, 18, 23, 24, 29 to 34, 42, 43, 45, and 46, the same PPS-based resin composition as in Example 1 was used [PPS (1) ]. Furthermore, in Example 2 using a PPS resin [PPS (2)], a glass-based filler was added to the resin composition in an amount of 40% by mass. Filling materials, Examples 5 to 9, 15 to 17, 19 to 22, 25 to 28, 35, 36, 44, and 47 using PBT, and Examples 10 and 11 using PP are based on resin composition. 30 mass% of the glass-based filler is added to the material, and in Examples 37 to 40 using POM, 25 mass% of the glass-based filler is added, and in Example 41 where LCP is used, the additive is added. 50% by mass of glass-based filler.

In Examples 3 and 27, as the durability evaluation test, the same test piece as the aluminum-resin joint used in the evaluation test of the bonding strength was used, and the following cold and hot shock test was performed, and the results after the cold and hot shock test were evaluated. Joint strength.

[Cold and hot shock test]

A cold and hot impact tester [manufactured by Espec] was used to perform a cold and hot impact test under predetermined cycle conditions, and was taken out after 100 cycles. The joint strength evaluation test was performed in the same manner as in Example 1 to evaluate durability.

The above-mentioned cycle conditions are in Example 3, after heating at 160 ° C for 1.5 hours, cooling down to -40 ° C for 1.5 hours, and then heating up to 160 ° C for 1 hour. 27. After heating at 140 ° C for 1.5 hours, the temperature was lowered to -40 ° C for 1.5 hours, and then the temperature was increased to 140 ° C for 1 hour.

The results are shown in Tables 1 to 8.

[Comparative Examples 1 to 18]

Film formation treatment of aluminum substrate, oxygen-containing film, oxygen-containing film, The resin composition and the resin molding conditions are shown in Tables 9 to 11, respectively, and the joint strength evaluation test was performed in the same manner as in Example 1.

In Comparative Examples 4 and 7 to 10, the same PPS-based resin composition [PPS (1)] as in Example 1 was used. In Comparative Examples 1, 11, 17, and 18 using PPS resin [PPS (2)], 40% by mass of a glass-based filler was added to the resin composition, and Comparative Examples 2, 5, and PBT were used. In 12 and 16, and in Comparative Examples 3, 6, and 15 using PP, 30% by mass of a glass-based filler was added to the resin composition, and in Comparative Example 13 using POM, 25% by mass was added. The glass-based filler was 30% by mass of the glass-based filler in Comparative Example 14 using LCP.

In Comparative Examples 4 to 6, the roughening treatment as the pretreatment and the film formation treatment (surface treatment) for forming an oxygen-containing film were not performed, and for Comparative Examples 9 and 10, the formation of an oxygen-containing film was not performed. In the film formation treatment (surface treatment), except that an aluminum substrate was used, an aluminum resin bonded body was produced in the same manner as in the above-mentioned Example, and an evaluation test of the bonding strength was performed in the same manner as in Example 1.

In Comparative Examples 7 and 8, the conductivity of hot water was adjusted to the values shown in Table 10 using 0.1M NaOH water.

The results are shown in Tables 9 to 11.

[Reference Example of Film Formation Process of Oxygen-containing Film]

The same aluminum substrate as in Example 1 was subjected to a film formation treatment using hot water at a temperature of 95 ° C. for 1 minute using tap water having a conductivity of 25 mS / m.

As a result, the thickness of the oxygen-containing film formed on the surface of the aluminum substrate does not exceed 0.02 to 0.05 μm, although the thickness varies.

[Industrial availability]

The metal-resin bonded body of the present invention has excellent bonding strength before and after the endurance test. Therefore, the metal-resin bonded body can be used for manufacturing various parts such as automotive sensing parts, household electrical parts, and industrial machine parts.

Claims (21)

A metal-resin joint comprising: a metal substrate made of a metal; an oxygen-containing oxygen-containing film formed on a surface of the metal substrate by intentionally applying a treatment for increasing an oxygen content; and A resin molded body formed of a thermoplastic resin composition bonded to the oxygen-containing film, the thermoplastic resin composition contains an additive compound having a functional group capable of reacting with the oxygen-containing film, and the additive compound is It has at least one selected from the group consisting of a carboxyl group and a salt thereof, an epoxy group, an epoxy propyl group, an isocyanate group, a carbodiimide group, an amine group and a salt thereof, and an acid anhydride group and an ester thereof. The functional group, the functional group of the aforementioned additive compound, is contained in the thermoplastic resin composition at a ratio of 0.5 to 150 μmol / g. The metal-resin bonded body according to claim 1, wherein the additive compound is an olefin-based copolymer comprising a constituent unit derived from an α-olefin and a constituent unit derived from an propylene oxide of an α, β-unsaturated acid. The metal-resin bonded body according to claim 1, wherein the additive compound is an olefin-based copolymer containing a constituent unit derived from a (meth) acrylate. For example, the metal-resin bonded body of claim 1, wherein the metal substrate having an oxygen-containing film on the surface before the resin molded body is bonded is a surface layer from the outermost surface to a depth of 3 μm, and the oxygen content rate measured by EPMA is Within the range of 0.1 to 50% by weight. The metal-resin bonded body according to claim 1, wherein the method of bonding the resin molded body to the oxygen-containing film is a method of injection molding or thermocompression bonding. The metal-resin bonded body according to claim 1, wherein the metal substrate on which the oxygen-containing film is formed is an aluminum substrate composed of aluminum or an aluminum alloy. The metal-resin bonded body according to claim 1, wherein the oxide film obtained by the film formation treatment is an oxide film having a thickness of 0.06 μm or more and 2 μm or less. The metal-resin bonded body according to claim 1, wherein the oxygen-containing film is a zinc-containing film containing zinc element obtained by a film-forming treatment using an alkaline aqueous solution containing zinc ions. For example, the metal-resin joint of claim 1, wherein the oxygen-containing film is formed by a film forming process using hot water having a conductivity of 0.01 mS / m or more and 20 mS / m or less and 91 ° C or more and 100 ° C or less, and the thickness is 0.1. A hydrated oxide film having a thickness of 1 μm or more and 1 μm or less. For example, the metal-resin joint of claim 1, wherein the thickness of the oxygen-containing film is 0.1 by a film forming treatment using warm water having a conductivity of 0.01 mS / m to 20 mS / m and a temperature of 60 ° C to 90 ° C. A hydrated oxide film having a thickness of 1 μm or more and 1 μm or less. The metal-resin bonded body according to claim 1, wherein the oxygen-containing film is an oxide film obtained by subjecting a surface of an aluminum substrate to a laser film-forming treatment. The metal resin joined body according to any one of claims 1 to 11, wherein the thermoplastic resin constituting the thermoplastic resin composition is selected from the group consisting of polyarylene sulfide resin, polyester resin, polycarbonate resin, and Acetal-based resin, polyether-based resin, polydiphenylene-based resin, polyfluorene-based resin, polyether-fluorine-based resin, liquid crystal polymer, fluorene-based resin, polyphenylene-ether-based resin, polyfluorene-based resin Resin and any one or more resins in the group consisting of polypropylene resin. A method for producing a metal-resin bonded body, comprising the steps of: a film forming step for forming an oxygen-containing film by intentionally applying a treatment for increasing an oxygen content on a surface of a metal substrate made of a metal; and The resin forming step of forming a resin molded body by injection molding of a thermoplastic resin composition on the oxygen-containing film of the surface-treated metal substrate obtained in this film-forming step is performed through the aforementioned oxygen-containing film to A method for producing a metal-resin bonded body of a metal-resin bonded body in which a metal substrate and a resin molded body are manufactured, the thermoplastic resin composition contains an additive compound having a functional group capable of reacting with an oxygen-containing film, and the additive compound has At least one selected from the group consisting of a carboxyl group and a salt thereof, an epoxy group, an epoxy group, an isocyanate group, a carbodiimide group, an amine group and a salt thereof, and an acid anhydride group and an ester thereof; The functional group is added to the thermoplastic resin composition, and the functional group of the additive compound is added at a ratio of 0.5 to 150 μmol / g. The method for producing a metal-resin joint according to claim 13, wherein the metal substrate on which the oxygen-containing film is formed is an aluminum substrate composed of aluminum or an aluminum alloy. The method for manufacturing a metal-resin joint according to claim 14, wherein the film formation step is performed by immersing the aluminum substrate in a ratio of 1 to 100 by weight (MOH / Zn ²⁺ ) containing alkali hydroxide (MOH) and The film formation treatment of the zinc ion (Zn ²⁺ ) -containing alkaline aqueous solution containing zinc ions, and a zinc-containing film containing zinc element is formed on the surface of the aluminum substrate. The method for producing a metal resin joined body according to claim 15, wherein the alkali source in the alkali aqueous solution containing zinc ions is any one selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide, or Two or more types of alkali hydroxide. The method for producing a metal resin joint according to claim 15, wherein the source of zinc ions in the aqueous alkali solution containing zinc ions is selected from the group consisting of zinc oxide, zinc hydroxide, zinc peroxide, zinc chloride, zinc sulfate, and zinc nitrate. Any one or more zinc salts in the group. For example, the method for manufacturing a metal-resin joint according to item 14, wherein the film formation step is performed on the surface of the aluminum substrate, and the electrical conductivity is from 0.01 mS / m to 20 mS / m to 91 ° C to 100 ° C. A film forming treatment of hot water forms a hydrated oxide film having a thickness of 0.1 μm to 1 μm. For example, the method for manufacturing a metal-resin joint according to claim 14, wherein the film formation step is performed on the surface of the aluminum substrate, and a temperature of 60 ° C to 90 ° C is used when the conductivity is 0.01 mS / m or more and 20 mS / m or less The film formation treatment of water forms a hydrated oxide film having a thickness of 0.1 μm to 1 μm. The method for manufacturing a metal-resin bonded body according to claim 14, wherein the film formation step is to form an oxide film by applying a film formation treatment to heat a laser treatment near the surface of the aluminum substrate. The method for producing a metal resin joint according to any one of claims 13 to 20, wherein the thermoplastic resin constituting the thermoplastic resin composition is selected from the group consisting of polyarylene sulfide resin, polyester resin, and polycarbonate resin. Resins, polyacetal resins, polyether resins, polydiphenyl ether resins, polyimide resins, polyether imine resins, liquid crystal polymers, ammonium resins, polyphenylene ether resins, poly Any one or two or more resins in the group consisting of a fluorene-based resin and a polypropylene-based resin.