JP2022187795A - Method for manufacturing composite member of plated metal and resin, and composite member - Google Patents

Abstract

To expand a variation of materials that can constitute a base material in a composite member made by joining a base material and resin.SOLUTION: A method (M10) for manufacturing a composite member (10) including a base material (11), a metal coating (12) covering the base material (11), and a resin (resin member 13) bonded to a surface of the metal coating (12) includes: a removal process (S12) of removing an oxide film (natural oxide film) covering the surface of the metal coating (12); a hot water treatment process (S13) of applying hot water treatment to the surface; and a bonding process (S14) of bonding the resin to the surface.SELECTED DRAWING: Figure 5

Description

The present invention relates to a composite member including a base material, a metal coating covering at least a portion of the base material, and a resin bonded to the surface of the metal coating.

Patent Document 1 discloses a technique related to a composite member including an aluminum member having an aluminum hydroxide film formed on the surface thereof and a resin member directly contacting the surface of the aluminum member having the aluminum hydroxide film formed thereon. (See, for example, FIG. 1 of Patent Document 1).

JP 2020-131492 A

However, when adopting the technique of Patent Document 1, the material constituting the base material is limited to aluminum.

One aspect of the present invention has been made in view of the above-described problems, and an object thereof is to expand the variation of materials that can constitute the base material in a composite member formed by bonding a base material and a resin. .

In order to solve the above problems, a method for manufacturing a composite member according to a first aspect of the present invention includes a base material, a metal coating covering at least a portion of the base material, and a metal coating bonded to the surface of the metal coating. and a method of manufacturing a composite member. The method for manufacturing the composite member includes a removal step of removing an oxide film covering the surface of the metal coating, a hot water treatment step of subjecting the surface subjected to the removal step to a hot water treatment, and the hot water treatment step. and a bonding step of bonding a resin to the surface on which the

In order to solve the above problems, a composite member according to a sixth aspect of the present invention comprises a base material and a metal coating covering at least a part of the base material, A metal coating having a surface provided with a needle-like structure made of at least one of an oxide and an oxide, and a resin bonded to the surface of the metal coating.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, in a composite member formed by bonding a base material and a resin, it is possible to widen the variation of materials that can constitute the base material.

1 is a perspective view of a composite member according to a first embodiment of the invention; FIG. 2 is a cross-sectional view of the composite member shown in FIG. 1; FIG. FIG. 2 is an SEM image of the bonding region shown in FIG. 1 and in a state before resin bonding; FIG. The top SEM image has a magnification of x20,000 and the bottom SEM image has a magnification of x40,000. FIG. 2 is a cross-sectional view of a modified example of the composite member shown in FIG. 1; The left figure is a flow chart of the manufacturing method of the composite member according to the second embodiment of the present invention. The right figure is a cross-sectional view of the joint region after each step included in the manufacturing method of the composite member shown in the left figure. FIG. 6 is a flow chart of a modification of the removal step included in the method of manufacturing the composite member shown in the left diagram of FIG. 5; FIG.

[First Embodiment]
A composite member 10 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 is a perspective view of a composite member 10. FIG. FIG. 2 is a cross-sectional view of composite member 10 taken along line AA' shown in FIG. FIG. 3 is a scanning electron microscope (SEM) image of the bonding region 122 of the composite member 10 before the resin member 13 is bonded. The top SEM image has a magnification of x20,000 and the bottom SEM image has a magnification of x40,000. The state before bonding the resin member 13 means a state in which the hot water treatment step S13 shown in FIG. 5 has been performed and the bonding step S14 shown in FIG. 5 has not been performed. The composite member manufacturing method M10 including the hot water treatment step S13 and the bonding step S14 will be described later in the second embodiment.

As shown in FIG. 1 , composite member 10 includes base material 11 , metal coating 12 , and resin member 13 .

<Base material and metal coating>
As shown in FIG. 1, the base material 11 is shaped like a plate. In this embodiment, high-tensile steel is used as the material forming the base material 11 . However, the material forming the base material 11 is not limited to high-tensile steel, and can be appropriately selected according to the application. The material forming the base material 11 may be any of metal, glass, ceramic, and resin. That is, in the composite member 10, the base material 11 is not limited to the plated metal described in the title of the invention.

In this embodiment, as shown in FIG. 1 , a metal coating 12 is formed on one of a pair of main surfaces forming a base material 11 . That is, in this embodiment, one main surface, which is part of the base material 11 , is covered with the metal coating 12 . However, the area of the base material 11 covered with the metal film 12 may include the bonding area 122, which is the area to which the resin member 13 described later is bonded, and is a part of the surface of the base material 11. It may be there, or it may be the entire surface of the base material 11 .

In this embodiment, zinc is used as the material forming the metal coating 12 . In addition, in this embodiment, the metal coating 12 is formed on one main surface of the base material 11 using a plating method. However, the material forming the metal coating 12 is not limited to zinc as long as it is a metal. It should be noted that the material forming the metal coating 12 is preferably a material capable of forming the metal coating 12 using a plating method. Moreover, the method of forming the metal coating 12 on one main surface of the base material 11 is not limited to the plating method. That is, in the composite member 10, the metal coating 12 is not limited to the plating or plating film described in the title of the invention.

As described above, in this embodiment, as the base material 11 and the metal coating 12, a galvanized high-tensile steel plate called SPFC780 is used. Although the thickness of the metal coating 12 is not limited, it is typically 1 μm or more and 50 μm or less. In this embodiment, the thickness of the metal coating 12 is set to 25 μm.

<Resin member>
As shown in FIG. 1, the resin member 13 is shaped like a rectangular parallelepiped. In this embodiment, polyphenylene sulfide (PPS) resin is used as the material forming the resin member 13 . However, the material constituting the resin member 13 is not limited to the PPS resin as long as it is a resin, and can be appropriately selected according to the application. The material forming the resin member 13 may be engineering plastic, super engineering plastic, or fiber-reinforced plastic containing glass fiber, carbon fiber, or the like, other than PPS resin. Also, the material forming the resin member 13 may be a resin suitable as an adhesive. An example of a resin suitable as an adhesive is an epoxy resin.

<Joint area>
Hereinafter, when the main surface 121 of the metal coating 12 is viewed from the normal direction of the main surface 121 , a region where the metal coating 12 and the resin member 13 overlap is referred to as a bonding region 122 . In FIG. 1, the joint region 122 is illustrated by a virtual line (chain double-dashed line).

As will be described in the second embodiment with reference to FIG. 5, a region including the bonding region 122 of the main surface 121 is subjected to a removal step S12 using blasting and a hot water treatment step S13. .

By subjecting the bonding region 122 to the removal step S12 using blasting, the natural oxide film formed on the surface of the bonding region 122 is removed, and furthermore, a micro-sized uneven structure 123 is formed on the surface of the bonding region 122. (See FIG. 2).

Further, by performing the hot water treatment step S13 after the removal step S12, needle-like structures 124 made of zinc hydroxide and zinc oxide are formed on the surface of the uneven structure 123 of the bonding region 122. (See Figure 2). However, the needle-like structure 124 may be composed of zinc hydroxide and zinc oxide, or may be composed of at least one of zinc hydroxide and zinc oxide. A scanning electron microscope (SEM) image of the needle-like structure 124 formed on the surface of the uneven structure 123 of the bonding region 122 is shown in FIG. The top SEM image has a magnification of x20,000 and the bottom SEM image has a magnification of x40,000.

When zinc hydroxide and zinc oxide are compared, zinc hydroxide has higher wettability to the resin. Therefore, when the needle-like structure 124 is composed of zinc hydroxide and zinc oxide, by increasing the proportion of hydroxide in the needle-like structure 124, the bonding between the metal coating 12 and the resin member 13 is reduced. Strength can be increased.

The resin member 13 is joined to the joint region 122 by injection molding so that a portion of the resin member 13 overlaps the joint region 122 . When the resin forming the resin member 13 is injected into the joint region 122, the resin has fluidity. Therefore, the resin having fluidity is filled in the gaps of the needle-like structure generated by the hot water treatment step S13, and the injected resin is soon cured (see FIG. 2).
Thus, in the composite member 10 , at least a portion of the base material 11 is covered with the metal film 12 , and resin, which is a cured resin, is formed on the bonding region 122 which is at least a portion of the main surface 121 of the metal film 12 . Member 13 is joined. Therefore, the material forming the base material 11 may be any material that can partially cover the surface with the metal film 12 . That is, the material of the base material 11 may be any material that can form the metal film 12 on the surface by plating. Therefore, since the material forming the base material 11 is not limited to aluminum as in Patent Document 1, the composite member 10 can have a wider variety of materials that can form the base material. Further, in the composite member 10, even when at least part of the main surface of the base material 11 is covered with the metal film 12, the anchor effect can be obtained as in the case of the technique of Patent Document 1. Therefore, the bonding strength between the metal coating 12 and the resin member 13 can be increased to the same extent as in the technique of Patent Document 1.

(arithmetic mean slope and root mean square slope)
In the bonding region 122, the arithmetic mean inclination RΔa of the main surface 121 is preferably 0.10 or more and 0.60 or less, more preferably 0.15 or more and 0.55 or less, and 0.17 or more. 0.50 or less is particularly preferred. In addition, in the bonding region 122, the root-mean-square slope RΔq of the main surface 121 is preferably 0.20 or more and 0.70 or less, more preferably 0.25 or more and 0.65 or less, and 0 0.27 or more and 0.60 or less is particularly preferable.

Both the arithmetic mean slope RΔa and the root mean square slope RΔq are used as indicators of how much slope there is in a narrow space.

The bonding strength tends to decrease as the arithmetic mean slope RΔa decreases. When the arithmetic mean slope RΔa is 0.10 or more, a practical bonding strength of about 12 MPa can be obtained, and when the arithmetic mean slope RΔa is 0.15 or more, a more practical bonding strength of about 20 MPa can be obtained. Obtainable. In particular, when the arithmetic mean slope RΔa is 0.17 or more, sufficient joint strength can be obtained for welding structural parts of automobiles and the like. Further, if the arithmetic mean slope RΔa is 0.60 or less, the removal step S12 can be performed by blasting. In particular, when the arithmetic mean slope RΔa is 0.55 or less, the removal step S12 can be easily performed by blasting, and when the arithmetic mean slope RΔa is 0.50 or less, roughening by blasting is even easier. is.

Similarly, in the case of the root-mean-square slope RΔq, the joint strength tends to decrease as the root-mean-square slope RΔq decreases. When the root mean square gradient RΔq is 0.20 or more, a practical bonding strength of about 12 MPa can be obtained, and when the root mean square gradient RΔq is 0.25 or more, a more practical bonding strength of about 20 MPa can be obtained. Strength can be obtained. In particular, when the root-mean-square slope RΔq is 0.27 or more, sufficient bonding strength can be obtained for welding structural parts of automobiles and the like. Further, if the root-mean-square slope RΔq is 0.70 or less, the removal step S12 can be performed by blasting. In particular, when the root-mean-square gradient RΔq is 0.65 or less, the removal step S12 by blasting is easy to perform, and when the root-mean-square gradient RΔq is 0.60 or less, the removal step S12 by blasting is easy. It is easier to implement.

(thickness of layer consisting of hydroxide and oxide)
The thickness t (see FIG. 2) of the layer composed of hydroxide and oxide containing the needle-like structure 124 is preferably 50 nm or more and 2000 nm or less, more preferably 100 nm or more and 1000 nm or less. In this embodiment, the thickness t is 500 nm.

When the thickness t is less than 50 nm, it is difficult to obtain a practical bonding strength. This is because the resulting anchor effect is small. On the other hand, when the thickness t exceeds 2000 nm, the structure of at least one of hydroxide and oxide tends to take a porous structure instead of a needle-like structure. In that case, it becomes difficult for the resin to permeate into the inside of the porous structure, making it difficult to obtain a practical bonding strength. This is also because the obtained anchor effect is small. Therefore, when the thickness t is 50 nm or more and 2000 nm or less, the structure of the hydroxide and oxide can be made into a needle-like structure suitable for obtaining an anchor effect, and as a result, the bonding strength can be increased. can.

If the thickness t is less than 100 nm, the anchoring effect is insufficient and it is difficult to obtain a practical bonding strength. In addition, when the thickness t exceeds 1000 nm, the hydroxide film becomes brittle and is likely to break when a load is applied. Therefore, when the thickness t is 100 nm or more and 1000 nm or less, it is possible to ensure a practical bonding strength and to make it difficult for the hydroxide film to break due to the load.

<Uses of Composite Materials>
Applications of the composite member 10 include, for example, structural members for automobiles (for example, suspension members) and electrical components.

When the composite member 10 is used as part of a structural member, a high-tensile steel plate plated with galvanized steel is used as the base material 11 and the metal coating 12, and engineering plastic, super engineering plastic, or the like is used as the material constituting the resin member 13. is preferred.

Further, when the composite member 10 is used as a part of an electrical component, it is conceivable that a metal component such as a terminal is molded with resin. In this case, copper with a plated surface is used as the base material 11 and the metal coating 12, and PPS (polyphenylene sulfide) resin, PBT (polybutylene terephthalate) resin, and PPA (polyethylene terephthalate) resin are used as the materials constituting the resin member 13. phthalamide) resins are preferably used.

Simply molding metal (for example, copper) terminals with resin tends to create gaps at the interface between the metal and the resin, and moisture from the atmosphere easily enters through these gaps. Electric parts such as motors and power control units do not like humidity. Conventionally, therefore, the interface between the terminal and the resin has been further sealed with epoxy resin or the like in order to suppress the intrusion of moisture. Due to the anchor effect of the composite member 10, gaps are less likely to occur at the interface between the copper and the resin, so sealing using epoxy resin or the like can be omitted. That is, the inside of the modle can be sealed and the airtightness can be improved simply by molding metal parts such as terminals with resin.

<Modification>
A composite member 20 that is a modification of the composite member 10 will be described with reference to FIG. FIG. 4 is a cross-sectional view of a composite member 20 that is a modification of the composite member 10. As shown in FIG.

In the composite member 10 , the resin member 13 molded by injection molding is joined to the joining region 122 of the metal coating 12 . The composite member 20 uses two sets of high-tensile steel plates, a base material 11A and a metal coating 12A, and a base material 11B and a metal coating 12B. The base material 11A and the metal coating 12A, and the base material 11B and the metal coating 12B are both configured in the same manner as the base material 11 and the metal coating 12 of the composite member .

In addition, in the composite member 20, the metal coating 12A and the resin member 13 are interposed between the bonding region 122A of the metal coating 12A and the bonding region 122B of the metal coating 12B by interposing the resin member 13 functioning as an adhesive. are joined, and the metal coating 12B and the resin member 13 are joined.

Thus, it can be said that the composite member 20 is composed of the composite members 10A and 10B which are two sets of composite members 10 and has the resin member 13 in common. The composite member 20 configured in this manner is also included in the scope of the present invention.

[Second embodiment]
A manufacturing method M10 for a composite member according to a second embodiment of the present invention will be described with reference to FIGS. 5 and 6. FIG. The left diagram of FIG. 5 is a flow chart of the composite member manufacturing method M10. The right diagram of FIG. 5 is a cross-sectional view of the bonding region 122 after performing the steps S11 to S14 included in the composite member manufacturing method M10 shown in the left diagram. In the right diagram of FIG. 5, the illustration of the reference numeral "122" of the joint region 122 is omitted. Reference numeral "122" is illustrated in the cross-sectional view of FIG. FIG. 6 is a flowchart of a removing step S12A, which is a modification of the removing step S12 included in the manufacturing method M10.

Further, hereinafter, the composite member manufacturing method M10 is simply referred to as manufacturing method M10. The manufacturing method M10 can be suitably used to manufacture the composite member 10 described in the first embodiment. The composite member 10 includes a base material 11, a metal coating 12 covering at least a portion of the base material 11, and a resin member 13 bonded to a bonding region 122 that is at least a portion of the surface of the metal coating 12. It is a member.

In this embodiment, the manufacturing method M10 will be described as manufacturing the composite member 10 . A high-tensile steel plate is used as the base material 11 as described in the first embodiment.

As shown in FIG. 5, the manufacturing method M10 includes a plating step S11, a removal step S12, a hot water treatment step S13, and a bonding step S14.

<Plating process>
The plating step S11 is a step of forming the metal film 12 on one main surface of the base material 11 using a plating method (see the cross-sectional view of "S11" in the right figure of FIG. 5).

In this embodiment, one main surface which is part of the base material 11 is covered with the metal coating 12 . However, the area of the base material 11 covered with the metal coating 12 may include the bonding area 122 shown in FIG. may be the entire surface of the

In this embodiment, zinc is used as the material forming the metal coating 12 . However, the material forming the metal coating 12 is not limited to zinc as long as it is a metal. It should be noted that the material forming the metal coating 12 is preferably a material capable of forming the metal coating 12 using a plating method. However, the method of forming the metal coating 12 on one main surface of the base material 11 is not limited to the plating method. In that case, step S11 can be said to be a metal film forming step rather than a plating step.

If a metal plate (for example, a galvanized high-tensile steel plate) in which the metal coating 12 is formed in advance on the surface of the base material 11 is used as the starting material for the manufacturing method M10, the plating step S11 can be omitted. .

<Removal process>
When the base material 11 and the metal coating 12 are left in the atmosphere for a long time (for example, longer than 3 days), a natural oxide film is often formed on the main surface 121 of the metal coating 12. . The removing step S<b>12 is a step of removing the natural oxide film covering main surface 121 , which is the surface of metal coating 12 . Note that the natural oxide film is one aspect of the oxide film.

In this embodiment, blasting is used to remove the natural oxide film in the removing step S12. By using blasting, it is possible to form a micro-sized concavo-convex structure 123 on the surface while removing the natural oxide film (see the cross-sectional view of "S12" in the right figure of FIG. 5). Therefore, the main surface 121 having high metal activity and having a high anchoring effect can be obtained by performing the hot water treatment step S13, which will be described later.

In the blasting, the particle diameter of the injection material is preferably 10 μm or more and 710 μm or less, more preferably 20 μm or more and 500 μm or less, and particularly preferably 30 μm or more and 300 μm or less. Further, the injection pressure is preferably 0.05 MPa or more and 2.0 MPa or less, more preferably 0.3 MPa or more and 1.5 MPa or less, and 0.5 MPa or more and 1.0 MPa or less. Especially preferred.

When a natural oxide film of the metal (zinc in this embodiment) that constitutes the metal coating 12 is formed on the main surface 121 of the metal coating 12, the particle size of the injection material is 10 μm or more. A micro-sized concave-convex structure 123 can be formed on 121 . Moreover, since the particle diameter of the injection material is 300 μm or less, the possibility of damage to the metal coating 12 due to blasting can be reduced. When the particle diameter of the injection material is 10 μm or more and 710 μm or less, by adopting the injection pressure of 0.05 MPa or more and 2.0 MPa or less, the natural oxide film can be removed by blasting, and the main surface 121 It is possible to form the micro-sized concave-convex structure 123 on the surface and reduce the possibility that the metal coating 12 is damaged. A metal oxide film often has low wettability to a resin. Therefore, by performing the hot water treatment after removing the natural oxide film, the bonding strength in the composite member 10 can be increased to the same extent as in the technique of Patent Document 1. Examples of damage to the metal coating 12 that may occur when blasting is performed under inappropriate conditions include the injection material penetrating the metal coating 12, and the metal coating 12 breaking away from the main surface of the base material 11. exfoliation. This condition for blasting is suitable when the thickness of the metal coating 12 is 1 μm or more and 50 μm or less. When the thickness of the metal coating 12 is 1 μm or more, it is possible to reliably reduce the possibility of damage to the metal coating 12 while forming the micro-sized concave-convex structure 123 . Note that the thickness of 50 μm is a typical upper limit of the thickness of the metal coating 12 produced using the plating method.

(Modification of removal process)
In the removal step S12A, which is a modified example of the removal step S12, acid treatment can be used instead of blasting to remove the natural oxide film (see FIG. 6). The removal step S12A includes an ultrasonic cleaning step S121 and an acid treatment step S122.

The ultrasonic cleaning step S121 is a step of ultrasonically cleaning the main surface 121 of the metal coating 12 .

The acid treatment step S122 is a step of acid-treating the principal surface 121 . Acid treatment is also called pickling. In this modified example, hydrochloric acid is used as the acidic solution used in the acid treatment. However, the acidic solution used in the acid treatment is not limited to hydrochloric acid and can be selected as appropriate.

Main surface 121 of metal coating 12 from which the natural oxide film has been removed by acid treatment tends to have smaller irregularities than main surface 121 from which the natural oxide film has been removed by blasting. Therefore, even if the film thickness of the metal film 12 is thin, the natural oxide film can be removed without damaging the metal film 12 .

<Hot water treatment process>
The hot water treatment step S13 is a step of subjecting the main surface 121 subjected to the removal step S12 to a hot water treatment. By performing the hot water treatment step S13, zinc forming the main surface 121 is hydroxylated or oxidized according to the following chemical formula. As a result, on main surface 121 on which concave-convex structure 123 is formed, a needle-like structure made of at least one of zinc hydroxide and zinc oxide forming metal coating 12 is formed (see FIG. 5). See the cross-sectional view of "S13" in the right figure). The needle-like structure is shown in FIG. 3 as described in the first embodiment.

Zn+ _2H2O →Zn(OH) _{2 +} H2
Zn(OH) ₂ →ZnO+ _H2O

The temperature of the water used in the hot water treatment step S13 is preferably 50° C. or higher and 100° C. or lower, more preferably 60° C. or higher and 95° C. or lower, and 70° C. or higher and 90° C. or lower. Especially preferred. The treatment time in the hot water treatment is preferably 10 seconds to 100 minutes, more preferably 30 seconds to 80 minutes, and particularly preferably 1 minute to 60 minutes. .

If the temperature of the water used in the hot water treatment step S13 is less than 50°C, at least one of the metal hydroxide and metal oxide forming the metal film will not grow sufficiently. Therefore, it is difficult to increase the bonding strength because the obtained anchor effect becomes small. Moreover, since hot water of 100° C. or less can be obtained under atmospheric pressure, it can be easily realized.

Moreover, if the treatment time in the hot water treatment step S13 is less than 10 seconds, at least one of the hydroxide and oxide of the metal (zinc in this embodiment) forming the metal coating 12 does not grow sufficiently. Therefore, it is difficult to increase the bonding strength because the obtained anchor effect becomes small. Moreover, it was found that the thickness t (see FIG. 2) of the layer composed of at least one of the metal hydroxide and metal oxide forming the metal coating 12 tends to be saturated after the treatment time exceeds 100 minutes. rice field. Therefore, by setting the treatment time to 100 minutes or less, the hot water treatment can be efficiently performed.

The electric conductivity of the water used in the hot water treatment step S13 is preferably 0.05 μS/cm or more and 10 μS/cm or less, more preferably 0.08 μS/cm or more and 5 μS/cm or less. , 0.1 μS/cm or more and 1 μS/cm or less.

High electrical conductivity of water means that the concentration of impurities (especially metal ions) contained in hot water is high. If the electrical conductivity of the water is above 10 μS/cm (i.e. if the concentration of impurities is too high), the shape and/or size of the zinc hydroxides and/or oxides formed by the hydrothermal treatment Reproducibility tends to decrease. As a result, the joint strength in the composite member 10 tends to decrease.

Also, the lower the electrical conductivity of water, the higher the bonding strength described above. However, it was found that the bonding strength tends to saturate when the electrical conductivity falls below 0.05 μS/cm. Therefore, by setting the lower limit of the preferred range of electrical conductivity of water to 0.05 μS/cm, it is possible to prevent wasting the cost of removing impurities contained in hot water.

<Joining process>
The bonding step S14 is a step of bonding the resin member 13 to the surface of the bonding region 122 that has undergone the hot water treatment step S13. In the present embodiment, the resin member 13 is molded using an injection molding method so that a portion of the resin member 13 overlaps the joint region 122 . When the resin forming the resin member 13 is injected into the joint region 122, the resin has fluidity. Therefore, the resin having fluidity is filled in the gaps of the needle-like structure generated in the hot water treatment step S13, and the injected resin eventually hardens (see the cross-sectional view of "S14" in the right figure of FIG. 5). ). Therefore, in the composite member 10, even when at least part of the main surface of the base material 11 is covered with the metal film 12, the anchor effect can be obtained as in the case of the technique of Patent Document 1. Therefore, the bonding strength between the metal coating 12 and the resin member 13 can be increased to the same extent as in the technique of Patent Document 1.

The method of joining the resin member 13 to the surface of the joining region 122 in the joining step S14 is not limited to the injection molding method, and may be, for example, an induction heat compression molding method or a press molding method. Alternatively, as described for the composite member 20 with reference to FIG. 4, a method using a resin such as an epoxy resin that functions as an adhesive may be used.

[Additional notes]
The present invention is not limited to the first embodiment and the second embodiment described above, and various modifications are possible within the scope indicated in the claims, and technical means disclosed in different embodiments are possible. Embodiments obtained by appropriately combining the above are also included in the technical scope of the present invention.

[First embodiment and second embodiment]
The effects of the first and second examples of the present invention will be described in comparison with the first and second experimental examples.

In the first example, the second example, the first experimental example, and the second experimental example, galvanized high-tensile steel sheets were used as starting materials for manufacturing composite members. Therefore, the base material 11 is a high-tensile steel plate, and the material forming the metal coating 12 is zinc. The film thickness of the metal coating 12 made of zinc is 25 μm.

In the first example, the composite member 10 was manufactured by carrying out the manufacturing method M10 shown in FIG. That is, in the removing step S12, the natural oxide film was removed by blasting. In addition, the blasting conditions were such that the particle diameter of the injection material was 106 to 125 μm and the injection pressure was 1.0 MPa. As for the conditions of the hot water treatment in the hot water treatment step S13, a water temperature of 75° C. and a treatment time of 40 minutes were used. As a result, the thickness t (see FIG. 2) of the layer composed of hydroxide and oxide containing needle-like structures 124 was 500 nm. In the joining step S14, the resin member 13 made of PPS resin was directly joined to the joining region 122 of the metal coating 12 that had been subjected to the hot water treatment step S13 by injection molding. As conditions for injection molding, a mold temperature of 140° C., a resin temperature of 260° C., an injection speed of 10 mm/sec, a holding pressure of 50 MPa, and a holding time of 10 seconds were used. adopted.

In the second example, based on the manufacturing method M10, the removing step S12A shown in FIG. 6 was performed instead of the removing step S12. That is, in the second embodiment, the acid treatment is used to remove the natural oxide film formed on the surface of the metal film 12 . In this acid treatment, a hydrochloric acid solution with a concentration of 10% was used as the hydrochloric acid solution in which the high-tensile steel plate was immersed. Moreover, the processing time of the acid treatment was set to 10 seconds.

In the first experimental example, the hot water treatment step S13 was omitted based on the first example. Similarly, in the second experimental example, the hot water treatment step S13 was omitted based on the second example.

The joint strength (shear strength) was measured according to ISO 19095 using the composite members manufactured using the first embodiment, the second embodiment, the first experimental example, and the second experimental example. Measured by the test method in accordance with

Table 1 below shows the points of the first example, the second example, the first experimental example, and the second experimental example, and the shear strength of each composite member.

熱水処理工程Ｓ１３を実施した第１の実施例および第２の実施例においては、各複合部材においていずれも２５ＭＰａ以上となるせん断強度が得られた。

In the first example and the second example in which the hot water treatment step S13 was performed, each composite member had a shear strength of 25 MPa or more.

In the first experimental example in which the natural oxide film was removed by blasting and the hot water treatment step S13 was omitted, a shear strength of 14 MPa was obtained in the composite member. This shear strength was significantly lower than the shear strength of 31 MPa obtained by the first example.

In the second experimental example in which the acid treatment was used to remove the natural oxide film and the hot water treatment step S13 was omitted, the resin member was peeled off from the high-tensile steel plate immediately after the joining step S14 was performed. That is, in the composite member manufactured using the second experimental example, poor bonding was observed.

[Third Embodiment and Fourth Embodiment]
Based on the first and second embodiments, the third and fourth embodiments are embodiments in which the press molding method is used instead of the injection molding method in the joining step S14. In the press molding in the third and fourth embodiments, the resin member 13 made of carbon fiber reinforced thermoplastic resin (CFRTP manufactured by Toray Coatex) was directly bonded to the bonding region 122 of the metal coating 12. . As conditions for press molding, a molding temperature of 220° C., a molding pressure of 5 MPa, and a holding time of 5 minutes were adopted.

Moreover, based on each of the third example and the fourth example, the hot water treatment step S13 was omitted as the third experimental example and the fourth experimental example, respectively.

Using the composite members manufactured using the third embodiment, the fourth embodiment, the third experimental example, and the fourth experimental example configured in this way, the joint strength (shear strength) was measured according to JIS K6850. It was measured by a test method referring to "Tensile Shear Bond Strength Test". The width of the joint region 122 is 25 mm, and the length of the joint region 122 is 12.5 mm.

Table 2 below shows the shear strength in the third example, the fourth example, the third experimental example, and the fourth experimental example.

熱水処理工程Ｓ１３を実施した第３の実施例および第４の実施例においては、各複合部材においていずれも２５ＭＰａ以上となるせん断強度が得られた。

In the third example and the fourth example in which the hot water treatment step S13 was performed, a shear strength of 25 MPa or more was obtained in each composite member.

In the third experimental example in which the natural oxide film was removed by blasting and the hot water treatment step S13 was omitted, a shear strength of 16 MPa was obtained in the composite member. This shear strength was significantly lower than the shear strength of 32 MPa obtained by the third example.

In the fourth experimental example in which the natural oxide film was removed by acid treatment and the hot water treatment step S13 was omitted, the resin member was peeled off from the high-tensile steel plate immediately after the joining step S14 was performed. That is, in the composite member manufactured using the fourth experimental example, poor bonding was observed.

Reference Signs List 10, 10A, 10B Composite member 11, 11A, 11B Base material 12, 12A, 12B Metal coating 121 Main surfaces 122, 122A, 122B Joining region 123 Concavo-convex structure 124 Needle structure 13 Resin member (resin)
20 Composite member

Claims (9)

A method for manufacturing a composite member including a base material, a metal coating covering at least a portion of the base material, and a resin bonded to the surface of the metal coating,
a removal step of removing an oxide film covering the surface of the metal film;
a hot water treatment step of subjecting the surface subjected to the removal step to a hot water treatment;
a bonding step of bonding a resin to the surface that has been subjected to the hot water treatment step;
A method of manufacturing a composite member, characterized by: The removing step is a step of subjecting the surface to blasting,
In the blasting, the particle diameter of the injection material is 10 μm or more and 710 μm or less, and the injection pressure is 0.05 MPa or more and 2.0 MPa or less.
The method of manufacturing a composite member according to claim 1, characterized in that: The removing step is a step of subjecting the surface to an acid treatment.
The method of manufacturing a composite member according to claim 1, characterized in that: In the hydrothermal treatment step, the water temperature is 50° C. or higher and 100° C. or lower, and the treatment time is 10 seconds or longer and 100 minutes or shorter.
The method for manufacturing a composite member according to any one of claims 1 to 3, characterized in that: In the hot water treatment step, the electrical conductivity of water is 0.05 μS/cm or more and 10 μS/cm or less.
The method for manufacturing a composite member according to any one of claims 1 to 4, characterized in that: a base material;
a metal coating covering at least part of the base material, the metal coating having a surface provided with a needle-like structure composed of at least one of a hydroxide and an oxide of a metal constituting the metal coating; ,
and a resin bonded to the surface of the metal coating,
A composite member characterized by: The arithmetic mean slope of the surface is 0.10 or more and 0.60 or less.
The composite member according to claim 6, characterized in that: The root mean square slope of the surface is 0.20 or more and 0.70 or less.
The composite member according to claim 6 or 7, characterized in that: The thickness of the layer composed of at least one of the hydroxide and the oxide containing the needle-like structure is 50 nm or more and 2000 nm or less.
The composite member according to any one of claims 6 to 8, characterized in that:

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