JP7691730B2 - Metal composite material and its manufacturing method - Google Patents

Description

This specification relates to a metal composite material, a manufacturing method thereof, and a joining material therefor.

In general, joining of metal materials to each other, or joining of metal materials to other inorganic or organic materials can be done by welding or by using adhesives. However, when using adhesives, some kind of surface treatment of the metal material is often required (Patent Document 1).

It is also known that fullerenes can carburize the surfaces of various metal materials, thereby improving the hardness of the metal surface (Patent Document 2).

JP 2021-3819 A JP 2007-100210 A

However, even when joining metal materials together or different materials together after surface treatment, it remains difficult to obtain an integrated composite material with high joining strength.

This specification provides a metal composite material including a structure in which metal materials are joined, a manufacturing method thereof, and a joining material for the metal composite material.

The present inventors have been investigating various behaviors of fullerenes on the surface of metal materials with respect to bonding on the surface of metal materials, and have found that when fullerenes are heated on the surface of a metal material and a curable resin composition is also present, the bonding strength of the cured layer derived from the curable resin composition to the surface of the metal material is improved. Based on these findings, the present specification provides the following means.

[1] A metal composite material,
A metal material;
a cured material layer provided on a surface of the metal material and containing a cured resin;
Equipped with
A material comprising at least a decomposition product of fullerene or a compound derived from the decomposition product in the hardened layer and/or a surface layer of the metal material in contact with the hardened layer.
[2] The material according to [1], wherein the surface layer further comprises the cured resin or a part thereof.
[3] The material according to [1] or [2], wherein the resin cured product is a cured product of a resin curing composition containing an active hydrogen compound.
[4] The material according to any one of [1] to [3], wherein the metal material is at least one selected from an Fe-based material and an Al-based material.
[5] The material according to any one of [1] to [4], wherein one or more of the metal materials are integrated via one or more of the hardened material layers.
[6] The material according to any one of [1] to [5], wherein the resin cured product is an epoxy resin cured product.
[7] A method for producing a metal composite material, comprising the steps of:
providing fullerenes to a surface of a metal material;
providing a curable resin composition to the fullerene;
a step of curing the resin curable composition to obtain a resin cured product;
A method comprising:
[8] The method according to [7], further comprising a step of cleaving at least a portion of the carbon-carbon bonds in the fullerenes on the surface of the metal material.
[9] The method according to [8], wherein the step of cleaving the carbon-carbon bond comprises heating the fullerene in an acidic atmosphere.
[10] The method according to any one of [7] to [9], wherein the step of obtaining the resin cured product is a step involving heating or a step of curing the resin curable composition containing an active hydrogen compound.
[11] A joining kit for obtaining a metal composite material, comprising:
A first agent containing fullerene;
A second agent containing a curable resin composition;
A kit to prepare for.
[12] A metal material for composite formation with a cured resin, the metal material having at least fullerene or a decomposition product thereof on a surface thereof.
[13] A method for producing a metal material for composite formation with a cured resin, comprising the steps of:
providing fullerenes to a surface of a metal material;
breaking at least a portion of the carbon-carbon bonds in the fullerenes on the surface of the metal material;
A method comprising:

FIG. 1 is a diagram showing an example of the structure of a metal composite material disclosed in this specification. FIG. 2 is a diagram showing an example of a flow of a method for producing a metal composite material disclosed in this specification. 5A to 5C are diagrams showing the analysis results of the bonding interface of Fe-based substrates bonded with the heat-resistant thermosetting resin (epoxy resin) used in Example 1. In Figs. 3 to 5, the scale bar indicates 10 µm. FIG. 1 is a diagram showing the analysis results of the bonding interface of Fe-based substrates bonded with the heat-resistant thermosetting resin (epoxy resin) used in Example 1. FIG. 2 is a diagram showing the analysis results of the bonding interface of the Al-based base materials bonded with the heat-resistant thermosetting resin (epoxy resin) used in Example 1. FIG. 2 is a diagram showing the analysis results of the bonding interface of the Al-based base materials bonded with the heat-resistant thermosetting resin (epoxy resin) used in Example 1. FIG. 1 is a diagram showing the analysis results of the bonding interface of Fe-based substrates bonded with the heat-resistant thermosetting resin (epoxy resin) used in Example 1. FIG. 2 is a diagram showing the analysis results of the bonding interface of the Al-based base materials bonded with the heat-resistant thermosetting resin (epoxy resin) used in Example 1.

The disclosure of this specification relates to metal composite materials, manufacturing methods thereof, joining kits for metal composite materials, metal materials for composites, etc.

According to the metal composite material (hereinafter also referred to as composite material) disclosed in this specification, a cured layer of a resin curable composition is bonded to the surface of a metal material, and the cured layer and the metal material are well integrated to form a composite material. Since the metal material is integrated by the cured layer, the characteristics of the cured layer can be easily imparted to the metal material. Furthermore, by using the cured layer as a bonding layer, metal materials and even heterogeneous materials can be integrated, making it possible to provide metal composite materials of various forms, including composite forms that were previously difficult to achieve.

According to the method for producing a metal composite material disclosed in this specification (hereinafter also referred to as the production method), a metal composite material with a well-integrated cured layer can be produced by supplying fullerene to the surface of a metal material and curing the curable resin composition. Furthermore, when the curable resin composition is cured, a material having an affinity with the curable resin composition can be supplied to the curable resin composition, and the material can be integrated into the cured layer.

The bonding kit for obtaining a metal composite material disclosed in this specification contains fullerene and a curable resin composition, so that a cured layer that has good bonding properties with metal materials and different materials can be applied to the surface of the metal material.

The metal material for composites disclosed in this specification can have a joining surface on its surface that can be easily integrated with metal materials or different materials through the curing of the curable resin composition.

The disclosure of this specification will be described in detail below with reference to the appropriate drawings. Figure 1 shows an example of the structure of a composite material, and Figure 2 shows an example of the flow of a manufacturing method.

(metal composite material)
1, the composite material 2 includes a metal material 10 and a cured material layer 20, which is a layer provided on the surface of the metal material 10 and contains a cured resin material. Furthermore, the cured material layer 20 and/or a surface layer 30 of the metal material 10 in contact with the cured material layer 20 may contain at least a decomposition product of fullerene.

(metallic material)
The metal constituting the metal material 10 is not particularly limited, and examples thereof include metal-based materials such as simple metals and alloys. Examples of metals include iron (Fe), aluminum (Al), copper (Cu), and alloys containing these. Typical examples include Fe-based materials that are Fe or alloys thereof, and Al-based materials that are Al or alloys thereof. The metal material 10 of this specification may be a material entirely composed of such metals, or a metal material provided on the surface of a substrate of a different material in the form of a film or layer such as a metal foil.

The shape of the metal material 10 is not particularly limited and can have various three-dimensional shapes. It may have a specific three-dimensional shape by itself, such as a flat plate or a sphere, or it may have a three-dimensional shape that covers the surface of another substrate (including the outer and inner surfaces).

(cured material layer)
The cured material layer 20 containing a cured resin is provided on the surface of the metal material 10. The cured material layer 20 may be provided on at least a part of the surface of the metal material 10, and the thickness thereof is not particularly limited.

The cured material layer 20 contains a resin cured material. The resin cured material is not particularly limited, and may be a cured material of a thermosetting resin or a cured material of a thermoplastic resin. The resin cured material may be a resin having a monomer or oligomer as a polymerizable component that can react with activated carbon species or activated carbon generated by decomposition of fullerene, or a resin that can generate decomposition products that can react with activated carbon species or activated carbon during polymerization. Examples of such resins include epoxy resins, melamine resins, urea resins, unsaturated polyester resins, urethane resins, and alkyd resins. Examples of thermosetting resins include epoxy resins and urethane resins, and examples of thermoplastic resins include acrylic resins, methacrylic resins, styrene resins, propylene resins, polyamide resins, and polyethylene terephthalate.

For example, the epoxy resin is not particularly limited and may be appropriately selected from conventionally known epoxy resins depending on the application of the composite material. Examples of the epoxy resin include bifunctional epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol A/F type epoxy resin;
Novolac type epoxy resins such as phenol novolac type epoxy resins, cresol novolac type epoxy resins, and bisphenol A novolac type epoxy resins;
Multifunctional epoxy resins such as trisphenolmethane type epoxy resins;
Glycidylamine type epoxy resin;
Diglycidyl ethers of polyfunctional phenols, diglycidyl ethers of polyfunctional alcohols, and halides thereof;
Examples of the epoxy resin include heterocyclic ring-containing epoxy resins such as triglycidyl isocyanurate, and alicyclic epoxy resins such as hydrogenated bisphenol A type epoxy resins and hydrogenated bisphenol F type epoxy resins.

As the epoxy resin, it is preferable to use an epoxy resin having a bifunctional or higher epoxy group among the above, such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, alicyclic epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, diglycidyl ether of polyfunctional phenol, diglycidyl ether of polyfunctional alcohol, their halides, their hydrogenated products, etc., and several types can be used in combination. From the viewpoint of heat resistance, alicyclic epoxy resins can be preferably used. By using these epoxy resins, it may be possible to obtain a cured layer with excellent heat resistance.

The epoxy resin cured product is obtained by curing various epoxy resins with a curing agent as necessary. It may be preferable to use a curing agent in some cases, but the curing agent may be selected from conventionally known curing agents. As the curing agent, for example, aliphatic amines such as dicyandiamide and diaminophenylmethane, aromatic amines such as diaminophenylsulfone, and amine curing agents such as dicyandiamide; polyfunctional phenols such as phthalic anhydride, pyromellitic anhydride, phenol novolac, and cresol novolac, etc., may be used, and several types of these may be used in combination. As the curing agent, a curing agent that requires a curing reaction accompanied by heating or a curing agent that is an active hydrogen compound may be used. By using such a curing agent, fullerene may be activated in situ when obtaining a resin cured product. The amount of the curing agent may be appropriately determined depending on the type and amount of the thermosetting resin used in the resin composition of the present invention, and is not particularly limited.

The acrylic resin is not particularly limited, and may be appropriately selected from known polymers of monomers having a (meth)acryloyl group, such as (meth)acrylic acid and (meth)acrylate, copolymers of two or more of the above monomers, and copolymers containing different types of monomers. The urethane resin may be appropriately selected from various known urethane resins.

The cured material layer 20 can be obtained by preparing a curable resin composition that contains a known curing accelerator, inorganic filler, coloring agent, etc., as necessary, in addition to the cured resin, and supplying it to the surface of a metal material (more specifically, a surface to which fullerene or its decomposition products have been previously supplied) and curing it. Based on the composition of the curable resin composition, the cured material layer 20 can contain not only the cured resin, but also unreacted epoxy resin, crosslinking agent, and decomposition products thereof. The cured material layer 20 can further contain decomposition products of fullerene, which will be described in detail later.

(Fullerene)
Fullerene is a carbon cluster in which carbon atoms form a hollow closed shell structure, and the number of carbon atoms forming the closed shell structure is usually an even number between 60 and 130. Specific examples of fullerene include C60, C70, C76, C78, C82, C84, C90, C94, C96, and higher-order carbon clusters having more carbon atoms than these. These fullerenes and mixtures of the above fullerenes can be used as appropriate, and the number of carbon atoms is not particularly limited, but fullerene C60, C70, and mixtures thereof can be used from the viewpoint of ease of production. In addition to the above fullerenes, the fullerene may be a fullerene derivative in which a fullerene molecule is chemically modified with other molecules or functional groups.

The hardened layer 20 of the composite material 2 and the surface layer 30 in contact with the hardened layer 20 of the metal material 10 contain decomposition products of fullerenes or compounds derived from the decomposition products of fullerenes (hereinafter, these are collectively referred to as decomposition products, etc.). The decomposition products of fullerenes are not particularly limited, but include compounds obtained as a result of part of the carbon-carbon bonds constituting fullerenes being cut and oxides obtained by reacting the compounds with oxygen. Here, the decomposition products of fullerenes can be obtained by decomposing fullerenes in an oxidizing atmosphere such as air or oxygen at, for example, 250°C or higher, for example, 300°C or higher, or for example, 350°C or higher. Also, for example, 360°C or higher, for example, 370°C or higher, for example, 380°C or higher, or for example, 390°C or higher. The heating temperature can be set in consideration of the sublimation of fullerenes, and is, for example, 600°C or less, for example, 550°C or less, for example, 500°C or less, for example, 450°C or less, for example, 400°C or less, for example, 390°C or less, for example, 380°C or less, or for example, 370°C or less. From the above, a suitable heating temperature is, for example, 350°C or more and 450°C or less, for example, 350°C or more and 400°C or less, for example, 350°C or more and 390°C or less, for example, 350°C or more and 380°C or less, or for example, 350°C or more and 370°C or less.

Compounds derived from fullerene decomposition products include reaction products between various fullerene decomposition products and epoxy resins or their curing agents (crosslinking agents), and reaction products between fullerene decomposition products, epoxy resins, and curing agents. Such reaction compounds vary depending on the type of epoxy resin and curing agent used.

The cured material layer 20 contains the resin cured material based on the composition of the curable resin composition, and may contain unreacted epoxy resin, crosslinking agent, decomposition products and unreacted products thereof, and may further contain the decomposition products described above. The range of the cured material layer 20 that mainly contains decomposition products refers to a range of, for example, up to 200 μm, for example, up to 100 μm, for example, up to 50 μm, or for example, up to 30 μm in vertical distance from the interface between the cured material layer 20 and the metal material 10.

The surface layer 30 of the metal material 10 may also contain decomposition products. The surface layer 30 in contact with the hardened layer 20 refers to a range of, for example, up to 200 μm, for example, up to 100 μm, for example, up to 50 μm, or for example, up to 30 μm in vertical distance from the interface with the hardened layer 20. When the surface layer 30 contains decomposition products, the integrity with the hardened layer may be better. Also, for example, when the surface layer 30 contains a higher concentration of decomposition products between the surface layer 30 and the hardened layer 20, the integrity with the hardened layer 20 may be better than when it is not. The high concentration of decomposition products on the surface layer 30 side can be determined by comparing the content of at least one type of decomposition product at the same vertical distance, for example, within a range of 1 nm or less, from the interface between the metal material 10 and the hardened layer 20.

Detection and comparison of the contents of decomposition products in the hardened layer 20 and the surface layer 30 can be performed, for example, by obtaining a cross-sectional area (e.g., 100 μm × 100 μm) including the interface of the composite material 2 and analyzing the cross-section using TOF-SIMS (time-of-flight secondary ion mass spectrometry).

To incorporate decomposition products or the like into the surface layer 30 or to incorporate decomposition products or the like at a higher concentration into the surface layer 30, it is preferable that the fullerenes applied to the surface of the metal material 10 are decomposed by a heat treatment or the like prior to the formation of the hardened material layer 20 to generate fullerene decomposition products.

The surface layer 30 of the metal material 10 may further contain a cured resin or a part thereof. By containing a cured resin or a part thereof in the surface layer 30 of the metal material 10, the cured material layer 20 and the metal material 10 are well integrated. Examples of the part of the cured resin contained in the surface layer 30 include the resin before the cured resin and the curing agent. In addition, the part may include decomposition products of the cured resin. The presence or absence of the cured resin or a part thereof in the surface layer 30 of the metal material 10 can be detected by TOF-SIMS, as described above.

In this way, by including decomposition products in the hardened material layer 20 and/or the surface layer 30 on the hardened material layer side of the metal material, the hardened material layer 20 and the metal material 10 can exhibit good integrity. This allows the metal material 10 to exhibit various properties based on the hardened material layer 20. For example, the hardened material layer 20 can provide the metal material surface with surface layers for various purposes, such as a protective film, an antifouling film, an anticorrosion film, a coating film, and a decorative film.

Furthermore, the cured material layer 20 can be used as a bonding layer to form a composite material with another material via the cured material layer 20. The other material is not particularly limited as long as it is a material that can be bonded by curing the curable resin composition. When the other material is the same or a different metal material, it is preferable to supply the fullerene or its decomposition product that has been applied to the metal material 10 in advance to the surface of the other material. This is because the integrity of the cured material layer 20 with the surface of the other material is improved.

(Method of manufacturing metal composite material)
The manufacturing method disclosed herein may include a step of supplying fullerene to the surface of a metal material (fullerene supplying step), a step of supplying a curable resin composition to the fullerene (curable composition supplying step), and a step of curing the curable resin composition to obtain a cured layer containing a resin cured product (cured layer forming step). According to the manufacturing method, a cured layer having excellent integrity can be provided on the surface of a metal material, and characteristics based on the cured layer can be imparted to the metal material. Furthermore, in order to improve the integrity of the cured layer to the metal material, a step of cleaving carbon-carbon bonds in the fullerene (fullerene activation step) may be included.

The fullerene supplying process, fullerene activation process, curable composition supplying process, and cured material layer forming process will be described below with reference to FIG. 2.

(Fullerene supplying process)
The step of supplying fullerene to the surface of the metal material 10 is not particularly limited, and any fullerene may be used as long as it can be supplied to the surface of the metal material 10. The fullerenes that can be used in this step have already been described. Fullerene powder may be supplied to the surface of the metal material 10, the metal material 10 may be airtightly buried in fullerene powder, a compression-molded fullerene molded body may be rubbed onto the surface of the base material, fullerene dispersed or dissolved in water or an organic solvent may be appropriately supplied to the surface of the metal material 10, or a fullerene film may be formed on the surface of the base material by vacuum deposition. For simplicity, a fullerene solution may be prepared using an appropriate solvent such as xylene, and the fullerene solution may be supplied to the surface of the metal material 10. When a fullerene solution or dispersion is supplied to the surface of the metal material 10, it is preferable to dry the solvent.

(Fullerene Activation Step)
The fullerene activation process is a process in which at least a portion of the carbon-carbon bonds in the fullerenes on the surface of the metal material 10 are broken down to generate fullerene decomposition products and their oxides. The inventors have found that the generation and presence of such fullerene decomposition products allows the surface layer 30 of the metal material 10 to contain a large amount of decomposition products and the like when the composite material 2 is finally obtained, thereby improving the integrity. For this reason, the process of generating fullerene decomposition products is referred to as the fullerene activation process.

The fullerene activation process can be carried out by heating the metal material to which the fullerenes have been supplied. Such a heat treatment can be carried out in an oxidizing atmosphere such as oxygen or air.

The fullerene activation process may be carried out within the temperature range already described for a time period sufficient for fullerene to be decomposed sufficiently. The treatment time varies depending on the heating temperature and is not particularly limited, but may be, for example, 30 minutes or more, for example, 1 hour or more, for example, 2 hours or more, for example, 3 hours or more, or for example, 4 hours or more. It may also be, for example, 6 hours or less, for example, 5 hours or less, or for example, 4 hours or less.

The composition supply step in the latter stage can be performed without carrying out the fullerene activation step. Even without carrying out the fullerene activation step, fullerene decomposition products or compounds derived from the decomposition products can be contained in the surface layer 30 of the metal material 10, etc., in some cases, and as a result, good bonding can be obtained. For example, in the curing process of a curable resin composition containing an active hydrogen compound such as an amine-based curing agent (for example, when the cured product is a polymer of an active hydrogen compound and an epoxy group or a glycidyl group), fullerene is decomposed with the curing reaction of the resin, and fullerene decomposition products or compounds derived from the decomposition products can be contained in the surface layer 30 of the metal material 10, etc. In addition, when the cured product layer formation step involves heating at, for example, about 150°C to 200°C, and fullerene decomposition products are generated in situ in the cured product layer formation step, fullerene decomposition products or compounds derived from the decomposition products can be contained in the surface layer 30 of the metal material 10, etc.

(Composition supply process)
The composition supplying step is a step of supplying a curable resin composition to the non-activated or activated fullerenes on the surface of the metal material 10. The curable resin composition has already been described. The method of supplying the curable resin composition to the surface of the metal material having fullerenes (non-activated or activated) is not particularly limited, and a known method of supplying a resin composition or the like can be appropriately adopted. As the curable resin composition, various embodiments described above can be applied.

(Cured material layer formation process)
The cured layer forming step is a step of supplying the fullerene of the metal material 10 to cure the curable resin composition. The curing operation is determined by the epoxy resin and curing agent used in the curable resin composition, and the necessary time and temperature are provided so that the required curing conditions are satisfied. For example, the curing temperature is from room temperature to 300°C, 40°C to 300°C, or 60°C to 250°C, and is from 1 hour to 24 hours.

When forming the cured layer 20, appropriate pressure can be applied to the metal material 10 containing the curable resin composition. When the cured layer 20 is used as a bonding layer, appropriate pressure can be applied to the metal material 10, the composition, and other materials to be bonded.

When the fullerene activation process is performed in conjunction with the formation of the hardened layer 20, the surface layer 30 of the metal material 10 tends to contain fullerene decomposition products and compounds derived from fullerene decomposition products, which are reaction products of fullerene decomposition products and resin cured products or parts thereof. For this reason, the hardened layer 20 is well integrated with the surface of the metal material 10. In addition, the resin cured product or parts thereof themselves tend to be contained in the surface layer 30. Even if the hardened layer 20 is formed without the fullerene activation process, the hardened layer 20 tends to contain decomposition products and the like due to heating and the presence of active hydrogen compounds in the hardened layer formation process, and decomposition products and the like may also be contained in the surface layer 30. Therefore, the hardened layer 20 is well integrated with the surface of the metal material 10 without the fullerene activation process.

By using the above steps, a hardened layer 20 can be formed on the surface of the metal material 10 to obtain the composite material 2. The manufacturing method can be modified in various ways, and a person skilled in the art can appropriately obtain the various forms of composite materials already described.

For example, when the hardened material layer 20 is used as a bonding layer, prior to the hardened material layer forming step, another metal material having activated or inactivated fullerenes on its surface can be brought into contact with the composition surface of the metal material that has been subjected to the composition supplying step, thereby obtaining a composite material 2 in which the metal material 10 and another metal material are bonded via the hardened material layer 20. Also, for example, when the metal material 10 and a non-metallic material are bonded via a hardened material layer, the surface of the non-metallic material does not need to be supplied with fullerenes.

(Metal material for forming a composite with a resin cured layer, its manufacturing method, and surface treatment method for a metal material)
According to the above-described method for producing the composite material 2, the hardened layer 20 having excellent integrity can be provided to the metal material 10. According to the above disclosure, a metal material for composite formation suitable for providing such a hardened layer 20 and a method for producing the same are also provided. That is, a metal material for composite formation with a resin hardened layer, which has a fullerene decomposition product on its surface, and a method for producing the metal material for composite formation with a resin hardened layer, which includes a step of supplying fullerene to the surface of the metal material and a step of cutting carbon-carbon bonds in the fullerene, are also provided. According to this metal material and its method for producing the same, a metal material capable of bonding the hardened layer 20 with good integrity can be provided. This production method can also be carried out as a surface treatment method for a metal material. The step of cutting a part of the carbon-carbon bonds in the metal material, fullerene, fullerene decomposition product, and fullerene may include various aspects as already described.

(Joining kit for obtaining metal composite materials)
The joining kit for obtaining a metal composite material disclosed in the present specification can include a first agent containing fullerene and a second agent containing a curable resin composition. As described above, by interposing fullerene on the surface of the metal material 10, when the curable resin composition is supplied and cured, a composite material 2 including a well-integrated metal material 10 and a cured product layer 20 can be obtained. Therefore, by preparing a kit in which the first agent contains fullerene and the second agent contains a curable resin composition, the composite material 2 can be easily obtained. The fullerene and the curable resin composition can include various aspects as already described.

Below, we will explain examples that embody the disclosure of this specification. However, the following examples are intended to provide further specific explanations of the disclosure of this specification and are not intended to limit the disclosure of this specification.

(Joining of metal materials with a resin-cured layer)
In this example, a two-part heat-resistant curable resin composition, DENATITE XNR6813 (resin) and XNH6813 (curing agent) (manufactured by Nagase & Co., Ltd.) or a structural curable resin composition, Araldite 2012 (manufactured by HUNTSDMAN Co., Ltd.), and fullerene (Nanomix (composed of 50-65% C60, 15-25% C70, and other higher fullerenes) manufactured by Frontier Carbon Corporation) were used to bond cold-rolled steel SPC270 as an Fe-based material and aluminum die-cast alloy ADC12 as an Al-based material, and the bonding strength was analyzed.

(Preparation of Joint Example 1)
For each metal material, a test piece of 25 mm x 100 mm was prepared, and the surface was degreased by wiping with acetone. For these test pieces, the end portion of the test piece, 25 mm x 30 mm, was used as the mutual bonding area. First, the following operation was performed on the bonding area of the Fe-based material and the Al-based material to prepare a bonded body Example 1.

A fullerene saturated solution (solvent: xylene, 8.7 mg/ml) was prepared, and 0.5 ml of the fullerene saturated solution was dropped onto each of the bonding areas of the Fe-based test piece and the Al-based test piece, followed by drying. The test pieces were heated at 350°C for 2 hours in an air atmosphere to activate the fullerenes. Each test piece was left to reach room temperature. Then, 0.5 ml of the heat-resistant curable resin composition (liquid) was dropped onto the bonding area of the Fe-based test piece, and the bonding area of the Al-based test piece was immediately placed over this bonding area, a 380 g weight was applied, and the bonding area was preheated at 80°C for 2 hours, followed by heating at 180°C for 2 hours to produce a bonded body.

(Preparation of Joint Example 2)
A bonded body was produced by performing the same operation as in Bonded Body Example 1, except that the heat treatment of the fullerene was not carried out, and the curable resin composition was cured without the heat treatment of the fullerene.

(Preparation of Joint Example 3)
A bonded body was produced by curing the curable resin composition in the same manner as in Bonded Body Example 1, except that the structural curable resin composition was used as the curable resin composition.

(Preparation of Joint Example 4)
A bonded body was produced by curing the curable resin composition without heat treatment of the fullerene in the same manner as in Example 1 of bonded body, except that a structural curable resin composition was used as the curable resin composition and heat treatment of the fullerene was not performed.

(Preparation of Joint Comparative Example 1)
A bonded body was produced by curing the curable resin composition without the presence of fullerene in the same manner as in Bonded Body Example 1, except that the dripping of the fullerene saturated solution and the heat treatment of the fullerene were not performed.

(Preparation of Comparative Example 2 of Bonded Body)
A bonded body was produced by curing the curable resin composition without the presence of fullerene in the same manner as in Bonded Body Example 3, except that the dripping of the fullerene saturated solution and the heat treatment of the fullerene were not performed.

A tensile test was conducted on these joint examples 1 to 4 and joint comparison example 1 to evaluate the joint strength. The results are shown below. The tensile test was conducted by attaching both ends of the joint to a tension and compression tester, pulling it, and measuring the strength at break. The tension and compression tester used was an Autograph AG-Xplus 50KN manufactured by Shimadzu Corporation, and the test was conducted at a tension speed of 1mm/min.

As shown in Table 1, the bonded bodies Examples 1 and 3 involving the heat treatment of fullerene were bonded with high strength, but the bonded bodies Examples 2 and 4 not involving the heat treatment of fullerene were also bonded with significantly higher strength than the bonded bodies Comparative Examples 1 and 2 not using fullerene. In addition, in the bonded bodies Examples 1 and 3, the hardened layer itself broke, but in the bonded body Example 2, the hardened layer peeled off on the surface of the Fe-based test piece, and in the bonded body Example 4, peeling occurred on both the Fe-based side and the Al-based side. In the bonded body Comparative Example 2, only the Fe-based side peeled off and broke.

From the above, it was found that by using fullerene as an intermediate, high bonding strength can be obtained even without heat treatment, and even higher bonding strength can be obtained by performing heat treatment. Furthermore, in bonding involving heat treatment of fullerene, the hardened layer itself breaks, indicating that it is firmly bonded to the metal base.

In this example, in order to confirm the distribution of fullerene decomposition products near the bonding interface of the bonded body produced in Example 1, a test specimen for evaluation was produced in accordance with Example 1, and molecular species were detected by TOF-SIMS.

Test specimens were prepared: SPC270 (Fe-based material, cold-rolled steel) with and without fullerene coating and activation treatment, and ADC12 (Al-based material, aluminum die-cast alloy) with and without fullerene coating and activation treatment. The heat-resistant curable resin composition used in Example 1 was applied to each specimen, and they were immediately heated at 80°C for 2 hours and then at 180°C for 2 hours to bond them together. After cooling, the bonded specimen was cut to include the bonding interface, and molecular species were detected by TOF-SIMS using a 100 μm x 100 μm region of the cut surface as the analysis target. Note that this TOF-SIMS can detect elements or molecular species present at a depth of 1 nm or less from the surface. The results are shown in Figures 3 to 5.

Figures 3 and 4 show the evaluation results for the bonded interface between the epoxy resin cured material and Fe (SPC270) and Al (ADC12), respectively. Note that the left side of each figure shows the results for a bonded body that was not subjected to fullerene activation treatment, and the right side shows the results for a bonded body that was subjected to fullerene activation treatment. In addition, at both ends of each figure, the Fe analysis results and Al analysis results of each bonded body are shown, respectively, to show the interface. Furthermore, the molecular species whose composition formula was identified were identified as fullerene decomposition products and reaction products of fullerene decomposition products and epoxy resin, based on their composition, etc.

Figures 3A and 3B show the evaluation results of the Fe side joint interface of the test specimen. As shown in these figures, it was found that fullerenes and fullerene decomposition products penetrated further into the Fe surface layer (at a vertical distance of at least 30 μm from the joint interface toward the deeper part) in the joint that had been activated. In addition, the reaction products of the epoxy resin and the crosslinking agent and the epoxy resin decomposition products penetrated further into the Fe surface layer in the joint that had been activated. The reaction products of the fullerene decomposition products and the epoxy resin and the reaction products of the fullerene decomposition products, the epoxy resin, and the crosslinking agent penetrated into the Fe surface layer regardless of activation.

Figures 4A and 4B show the evaluation results of the Al-side bonded interface of the test specimen. As shown in these figures, it was found that fullerenes and fullerene decomposition products penetrated further into the Al surface layer (at a vertical distance of at least 30 μm from the bonded interface toward the deeper part) in the bonded body that had been activated. In addition, the reaction product of the epoxy resin and the crosslinking agent penetrated further into the Al surface layer in the bonded body that had been activated. The epoxy resin decomposition products, the reaction products of the fullerene decomposition products and the epoxy resin, and the reaction products of the fullerene decomposition products, the epoxy resin, and the crosslinking agent penetrated into the Fe surface layer regardless of activation.

Figures 5A and 5B also show the evaluation results for other molecular species at the Fe-side and Al-side bonding interfaces of the test specimens, as well as the evaluation results for a bonded body in which only epoxy resin was applied and cured. As shown in Figures 5A and 5B, it was found that the fullerene decomposition products, crosslinking agent, epoxy resin, and reaction products of epoxy resin and crosslinking agent all penetrated into the Fe surface layer and the Al surface layer (all within a vertical distance of at least 30 μm deep from the bonding interface).

In addition, Figures 3 to 5 show that the fullerenes are almost completely decomposed by the activation treatment, but that both the fullerenes and their decomposition products penetrate into the metal base side as a result of activation.

From the above, it was found that fullerene activation maintains fullerenes and fullerene decomposition products in a state of permeation into the surface layer of the metal base (a range of at least 30 μm vertically from the bonding interface toward the deeper side), and is present in smaller amounts on the resin side. It was found that such penetration of fullerene decomposition products into the surface layer side of the metal base contributes to improving the bonding strength.

Claims (12)

A metal composite material, comprising:
A metal material;
a cured layer provided on a surface of the metal material and containing a cured product of a heat-resistant thermosetting resin composition ;
Equipped with
a material comprising , at least in the surface layer of the cured material layer and the metal material in contact with the cured material layer , fullerene decomposition products in which at least a part of the carbon-carbon bonds of fullerene are cleaved, and the cured material of the heat-resistant thermosetting resin composition or a part thereof . The material according to claim 1 , wherein the cured product is a cured product of the heat-resistant thermosetting resin composition containing an active hydrogen compound. The material according to claim 1 or 2 , wherein the metal material is at least one selected from an Fe-based material and an Al-based material. The material according to any one of claims 1 to 3 , wherein one or more of said metal materials are integrated via one or more of said hardened material layers. The material according to any one of claims 1 to 4 , wherein the cured product includes a cured product of an epoxy resin . A method for producing a metal composite material, comprising the steps of:
providing fullerenes to a surface of a metal material;
providing a curable resin composition to the fullerene;
a step of curing the curable resin composition to obtain a cured resin product;
A method comprising: The method of claim 6 , further comprising breaking at least some of the carbon-carbon bonds in fullerenes on the surface of the metallic material. The method of claim 7 , wherein the step of breaking the carbon-carbon bonds comprises heating the fullerenes in an oxidizing atmosphere. The method according to any one of claims 6 to 8 , wherein the step of obtaining the cured resin product is a step involving heating or a step of curing the curable resin composition containing an active hydrogen compound. A joining kit for obtaining a metal composite material, comprising:
A first agent containing fullerene;
A second agent containing a curable resin composition;
A kit to prepare for. A metal material having at least fullerene or its decomposition product on its surface for composite formation with a cured resin. A method for producing a metal material for composite with a cured resin, comprising the steps of:
providing fullerenes to a surface of the metal material;
breaking at least a portion of the carbon-carbon bonds in the fullerenes on the surface of the metal material;
A method comprising:

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