JP2021088091A - Metal member for bonding to resin composition, method for producing metal-resin bonded body, and metal-resin bonded body - Google Patents

Abstract

To provide a metal member that can improve bonding strength with a resin composition.SOLUTION: A metal member for bonding to a resin composition has a plurality of projections, each of which projects from a surface of the metal member that is for bonding to the resin composition, and has a different cross-sectional area in the cross section along the flow direction of the resin composition that is to flow in contact with the metal member at the time of bonding. The plurality of projections are arranged so that their cross-sectional areas become smaller in the cross sections along the flow direction as they go downstream in the flow direction.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a metal member for bonding with a resin composition, a method for producing a metal resin bonded body, and a metal resin bonded body.

Various methods for producing a bonded body in which a resin and a metal member are bonded without using an adhesive have been studied. However, since resins and metals, which are originally dissimilar materials, have poor bonding strength, it is an issue to devise ways to improve these bonding strengths.

For example, in Patent Document 1, an uneven portion is formed on the surface of an aluminum shape body made of an aluminum alloy, and a resin is allowed to enter the concave portion of the uneven portion to be solidified, thereby joining the aluminum shape body and the resin molded body. Describes how to increase power. According to Patent Document 1, an aluminum shaped body and a resin molded body can be formed by forming a protruding portion protruding from a part of the concave portion to the inner side of the concave portion, or by further providing a concave portion or a convex portion inside the concave portion. It is said that the adhesion strength and airtightness of aluminum can be further improved.

Further, in Patent Document 2, the surface of an aluminum alloy base material is anodized to form nanopores, and the surface is corroded with an alkaline solution to form corroded pores. A method for increasing the bonding force between the base material and the resin is described. According to Patent Document 2, the aluminum alloy base material after the above treatment has a structure in which a large number of nanopores are formed inside the corroded pores.

Further, in Patent Document 3, a recess and a through hole penetrating from the bottom surface of the recess to the other surface are formed on one surface of the metal plate, the other surface is covered, and the through hole is passed through. It is described that the metal plate and the resin layer can be joined regardless of the material by forming the resin layer filled up to the inside of the recess. Patent Document 3 describes that the metal recessed due to the formation of the recesses protrudes to the other surface on the corresponding opposite side.

Japanese Unexamined Patent Publication No. 2011-121206 Special Table 2015-509557 Japanese Unexamined Patent Publication No. 2012-183705

As described in Patent Documents 1 to 3, many attempts have been made to process the surface of the metal member from the viewpoint of increasing the bonding strength between the resin composition and the metal member. In particular, if a structure capable of locking the resin is formed such as the protrusion described in Patent Document 1 and the through hole and the recess described in Patent Document 3, the resin composition is less likely to be separated from the metal member, and these It is stated that the joint strength of is higher.

However, according to the findings of the present inventors, even with the methods described in Patent Documents 1 to 3, the bonding strength between the resin composition and the metal member is expected to be high, especially when the thickness of the metal member is increased. Did not rise to.

An object of the present disclosure is a metal member capable of further increasing the bonding strength with the resin composition, a method for joining a metal-resin bonded body in which the resin composition and the metal member are bonded, and a metal resin produced by the method. The purpose is to provide a joint.

The metal member for joining with the resin composition according to one aspect is the resin composition that protrudes from the surface to which the resin composition of the metal member is joined and that flows in contact with the metal member at the time of joining. The plurality of convex portions have a plurality of convex portions having different cross-sectional areas along the flow direction, and the plurality of convex portions have a smaller cross-sectional area along the flow direction toward the downstream side with respect to the flow direction. Is located in.

Further, the method for manufacturing a metal-resin bonded body according to one aspect includes a step of arranging a metal member inside a mold and a step of injecting a resin composition into the inside of a mold in which the metal member is arranged. However, the arranged metal member has a plurality of convex portions having different cross-sectional shapes along the flow direction of the injected resin composition on the surface in contact with the injected resin composition. The plurality of convex portions are arranged so that the cross-sectional area of the cross section along the flow direction becomes smaller toward the downstream side with respect to the flow direction.

Further, the metal-resin bonded body according to one embodiment is a metal-resin bonded body having a metal member and a resin composition bonded to the surface of the metal member, and the metal member is bonded to the resin composition. The surface is provided with a plurality of convex portions having different cross-sectional areas in cross section along the flow direction of the resin composition that has flowed in contact with the metal member at the time of joining, and the plurality of convex portions are relative to the flow direction. It is arranged so that the cross-sectional area of the cross section along the flow direction becomes smaller toward the downstream side.

According to the present disclosure, a metal member capable of further increasing the bonding strength with the resin composition, a method for bonding a metal-resin bonded body in which the resin composition and the metal member are bonded, and a metal resin produced by the method. Joins are provided.

FIG. 1 is a schematic perspective view showing a metal member for joining with a resin composition according to the first embodiment. FIG. 2A is a schematic view showing how the metal member is arranged in the mold in the step of joining the resin composition to the metal member, and FIG. 2B is a schematic view showing how the core is moved to close the mold. .. 3A, 3B, 3C and 3D are schematic views showing how the molten resin composition is injected from the gate into the mold in the step of joining the resin composition to the metal member. FIG. 4 is a schematic view showing a metal-resin bonded body in which a metal member and a solidified resin composition are bonded. FIG. 5 is a schematic view showing how the resin composition shrinks and solidifies from both sides of the convex portion so as to tighten the convex portion when the resin composition solidifies. FIG. 6 is a schematic perspective view showing a metal member for joining with the resin composition according to the second embodiment. FIG. 7 is a schematic perspective view showing a metal member for joining with a resin composition according to a third embodiment. FIG. 8 is a schematic perspective view showing a metal member for joining with a resin composition according to a fourth embodiment. FIG. 9 shows a state of the metal member for joining with the resin composition and the resin composition injected into the mold and flowing in contact with the metal member according to the fifth embodiment. It is a schematic diagram.

Hereinafter, a plurality of embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below are examples, and the present invention is not limited to these embodiments.

[First Embodiment]
FIG. 1 is a schematic perspective view showing a metal member for joining with a resin composition according to the first embodiment.

As shown in FIG. 1, the metal member 100 is a plate-shaped member and has a plurality of convex portions 120 that are arranged on one surface 110 and project from the surface 110. One surface 110 is a surface to which the resin composition is bonded.

In the present embodiment, the plurality of convex portions 120 are a plurality of tubular protrusions that are independently arranged on the surface of the metal member 100. The shape of the convex portion 120, which is tubular, is not limited, and is columnar such as columnar, triangular columnar, square columnar, hexagonal columnar, elliptical columnar, pyramidal, pyramidal, inverted pyramidal (inverted taper). ) And other shapes. In the present specification, the tubular shape is a ratio of a minimum distance to a maximum distance of 0.5 or more among the distances connecting points on the outer circumference of the member in a cross section along the surface 110 of the metal member 100. It means a shape such that it is 1.0 or less.

The plurality of convex portions 120 are in contact with the metal member 100 at the time of joining and flow along the surface 110 in the flow direction of the resin composition (in FIG. 1, the direction of the white arrow; hereinafter, also simply referred to as “flow direction”). The shape and arrangement are such that the volume gradually decreases (the cross-sectional area of the cross section along the flow direction gradually decreases). Specifically, the convex portion 120b arranged on the downstream side of the flow direction with respect to the convex portion 120a arranged on the upstream side with respect to the flow direction is a convex portion having a smaller volume. .. Similarly, the convex portion 120c arranged on the downstream side of the convex portion 120b in the flow direction is a convex portion having a smaller volume. Further, the convex portion 120d arranged on the downstream side of the convex portion 120c with respect to the flow direction is a convex portion having a smaller volume.

2 and 3 are process diagrams showing how the resin composition is bonded to the metal member 100.

First, as shown in FIG. 2A, the metal member 100 is arranged in the mold 200. The mold 200 has a cavity 210 in which the metal member 100 is arranged and a core 220 which is a movable portion, and the core 220 is provided with a gate 230 for injecting the molten resin composition.

The metal member 100 is manufactured so that the volume of the convex portion 120 becomes smaller toward the downstream side with respect to the direction in which the resin composition injected from the gate 230 flows along the surface of the metal member 100 (flow direction). Has been done. Therefore, the metal member 100 arranged inside the mold 200 has a larger volume as the convex portion 120 located closer to the gate 230, and a smaller volume as the convex portion 120 located farther from the gate 230. .. The direction of the white arrow shown in FIG. 2A is the direction in which the volume of the convex portion 120 becomes smaller, similar to the arrow shown in FIG.

Next, as shown in FIG. 2B, the core 220 is moved to close the mold 200. At this time, the inside of the mold may be heated.

Next, as shown in FIG. 3A, the molten resin composition 300 is injected from the gate 230 into the mold 200. The injected resin composition 300 first comes into contact with the surface 110 of the surface 110 of the metal member 100, which is located immediately below the injection direction of the gate 230.

As shown in FIGS. 3B and 3C, the injected resin composition 300 flows along the surface 110 of the metal member 100 to fill the inside of the mold 200. The injection of the resin composition is carried out until the inside of the mold 200 is substantially completely filled with the resin composition 300 as shown in FIG. 3D.

Then, by cooling the resin composition 300 by cooling the mold 200 and solidifying it, as shown in FIG. 4, a metal resin bonded body 400 in which the metal member 100 and the solidified resin composition 300 are bonded is obtained from the mold 200. It can be taken out and obtained. When the metal resin bonded body 400 is taken out from the mold 200, the resin composition is cut near the outlet of the gate 230 to be separated from the resin composition inside the gate 230. At this time, the resin composition adhering to the metal resin bonded body 400 side after the division is then removed by post-processing such as polishing treatment, but it is very difficult to completely remove the adhering resin composition. Usually, the injection marks 410 as shown in FIG. 4 remain on the surface of the solidified resin composition 300.

Here, the metal generally has a high thermal conductivity. Therefore, when the resin composition 300 injected in FIGS. 3A to 3D flows, the heat of the resin composition 300 is continuously taken away by the metal member 100. Therefore, as the resin composition 300 flows, the temperature decreases, and the viscosity of the resin composition 300 increases and the fluidity decreases. Then, the resin composition 300 having reduced fluidity may not be able to come into close contact with the surface of the metal member 100. If the resin composition 300 is cooled and solidified in this state, voids are formed between the metal member 100 and the resin composition 300, and the resin composition cannot be sufficiently bonded to the metal member 100, and the bonding strength thereof is increased. Is hard to increase. In particular, in the metal member 100, the portion of the metal member 100 that is located farther from the gate 230 inside the mold 200, the more remarkable the decrease in bonding force due to the generation of voids due to the decrease in temperature and fluidity of the resin composition 300 is remarkable. is there.

Conventionally, it has been known that increasing the thickness of a metal member makes it difficult to increase the joint strength between the resin composition and the metal member. This is because, especially when the thickness of the metal member 100 is large, the metal member 100 can take a larger amount of heat, so that voids are likely to be generated due to the temperature decrease and the fluidity decrease of the resin composition 300 described above. It is thought that.

On the other hand, in the present embodiment, the plurality of convex portions 120 of the metal member 100 act as heat retaining portions for holding the heat received from the resin composition 300. Therefore, the resin composition around the convex portion 120 can easily maintain a predetermined temperature and the fluidity does not easily decrease, so that the resin composition can be solidified after being in close contact with the surface of the convex portion 120, whereby voids are generated. It is considered difficult to do.

Further, in the present embodiment, as shown in FIG. 5, when the resin composition 300 solidifies, it contracts and solidifies in the direction of the arrow in the figure so as to tighten the convex portions 120 from both sides of the convex portions 120. The cooled and shrunk resin composition 300 solidifies so as to be strongly adhered to the convex portion 120.

The convex portion 120 enhances the bonding strength between the solidified resin composition 300 and the metal member 100 by these actions. so that,

On the other hand, although the convex portion 120 retains the heat received from the resin composition 300, the convex portion 120 also removes the heat from the resin composition 300. Therefore, when the metal member 100 has a plurality of convex portions 120 on the surface 110, the resin composition is formed on the convex portions 120 on the flow path toward the downstream side with respect to the flow direction (flow direction) of the resin composition 300 inside the mold 200. Since the heat of the object 300 is taken away and the heat is cumulatively taken away by the convex portion 120, the temperature of the resin composition 300 tends to be extremely lowered. Therefore, simply arranging the plurality of convex portions 120 cannot sufficiently suppress the decrease in joint strength due to the decrease in fluidity on the downstream side with respect to the flow direction.

In the present embodiment, based on the above-mentioned new findings of the present inventors, the surface of the metal member 100 can be more sufficiently improved by arranging the convex portions 120 even on the downstream side in the flow direction. The volume of the plurality of convex portions 120 is changed according to the position on the 110.

Specifically, the metal member 100 is arranged on the downstream side with respect to the flow direction, and the convex portion 120c and the convex portion 120d that come into contact with the resin composition 300 whose temperature has decreased are convexes arranged on the upstream side. The volume is made smaller than that of the portion 120a and the convex portion 120b. As a result, the amount of heat taken by the convex portion 120c and the convex portion 120d is reduced, and the decrease in the bonding strength due to the decrease in the fluidity due to the cooling of the resin composition 300 on the downstream side with respect to the flow direction is suppressed.

As a result, the temperature of the resin composition 300 is extremely lowered on the downstream side with respect to the flow direction, and the fluidity is also extremely lowered, so that it is possible to make it more difficult for the bonding strength to be lowered on the downstream side. Therefore, the convex portion 120 retains heat on both the upstream side and the downstream side with respect to the flow direction to suppress the generation of voids due to the decrease in the fluidity of the resin composition 300, and the resin composition 300 has the convex portion 120. It is considered that the effect of improving the joint strength is sufficiently exerted by shrinking and solidifying as if tightening.

In the present embodiment, the interval between the convex portions 120 may be constant or may be changed. For example, in order to improve the joint strength by retaining heat by the convex portions 120 on the downstream side, the distance between the convex portions 120 is reduced toward the downstream side with respect to the flow direction (the convex portions 120 are arranged densely). ), Or, with the intention of reducing the amount of heat taken by the convex portion 120 on the downstream side and suppressing the decrease in joint strength, the distance between the convex portions 120 is increased toward the downstream side with respect to the flow direction (). The convex portion 120 may be roughly arranged). These are appropriately set according to the physical characteristics of the metal member 100 and the resin composition 300 (easiness of heat transfer and fluidity of the resin composition), the temperature of the resin composition 300 to be ejected, the temperature at which the mold 200 is heated, and the like. can do.

The metal-resin bonded body 400 (see FIG. 4) thus obtained has a metal member 100 and a resin composition 300 bonded to the surface 110 of the metal member 100, and the metal member 100 and the resin composition. A plurality of convex portions 120 are arranged on the surface 110 to which the 300 is joined. The plurality of convex portions 120 are arranged so that the closer to the injection mark 410, the larger the volume, and the smaller the volume in the direction away from the injection mark 410. In other words, the metal-resin bonded body 400 has a plurality of protrusions having a different cross-sectional area on the surface 110 where the metal member 100 and the resin composition 300 are bonded in a direction away from the injection mark 410. Has a part.

The resin composition 300 may be a fiber-reinforced resin composition containing reinforcing fibers 310 such as carbon fibers, glass fibers and cellulose nanofibers. Then, when the resin composition 300 flows in the mold 200, the reinforcing fibers 310 are likely to be oriented along the flow direction of the resin composition 300. At this time, the plurality of convex portions 120 are arranged so that the volume becomes smaller along the direction in which the reinforcing fibers 310 are oriented.

According to the above-described embodiment, the bonding strength between the metal member and the resin composition can be increased even when the thickness of the metal member is particularly large.

[Second Embodiment]
FIG. 6 is a schematic perspective view showing a metal member for joining with the resin composition according to the second embodiment.

As shown in FIG. 6, the metal member 600 is a plate-shaped member and has a plurality of convex portions 620 arranged on one surface 610. One surface 610 is a surface to which the resin composition is bonded. This embodiment differs from the first embodiment only in the shape of the plurality of convex portions 620. Therefore, only the differences from the first embodiment will be described, and the description of the overlapping parts will be omitted.

In the present embodiment, the plurality of convex portions 620 are a plurality of rod-shaped protrusions independently arranged on the surface of the metal member 600. The surface 610 is such that each rod-shaped protrusion extends in a direction different from the flow direction (in the direction of the white arrow in FIG. 6) of the resin composition that comes into contact with the metal member 600 at the time of joining and flows along the surface 610. It is arranged along. In the present embodiment, the plurality of convex portions 620 are arranged at intervals from each other so as to extend along a direction orthogonal to the flow direction (in FIG. 6, the direction of the shaded arrow).

The shape of the rod-shaped convex portion 620 is not limited, and may be any shape such as a triangular columnar shape, a square columnar shape, a hexagonal columnar shape, and an elliptical columnar shape. In the present specification, the rod shape means that the ratio of the minimum distance to the maximum distance among the distances connecting the points on the outer circumference of the metal member 600 in the cross section along the surface 610 is less than 0.5. It means a shape that becomes.

In the plurality of convex portions 620, the width of the convex portions in the flow direction gradually decreases along the flow direction of the resin composition 300 (in the direction of the white arrow in FIG. 6) (cross-sectional area of the cross section along the distribution direction). The shape and arrangement are such that Specifically, with respect to the convex portion 620a arranged on the upstream side with respect to the flow direction, the convex portion 620b arranged on the downstream side with respect to the flow direction from the convex portion 620a is a convex portion having a smaller width of the convex portion. It has become. Similarly, the convex portion 620c arranged on the downstream side of the convex portion 620b in the flow direction with respect to the convex portion 620b is a convex portion having a smaller width of the convex portion.

In the present embodiment, the convex portion 620b and the convex portion 620c arranged on the downstream side with respect to the flow direction of the resin composition 300 and coming into contact with the resin composition 300 whose temperature has decreased are the convex portions arranged on the upstream side. The width of the convex portion in the distribution direction (cross-sectional area of the cross section along the distribution direction) is made smaller than that of the portion 620a. As a result, the metal member 600 increases the bonding strength of the resin composition 300 by retaining heat in each of the convex portions 620, while reducing the amount of heat taken by the convex portions 620b and the convex portions 620c in the flow direction. On the downstream side of the resin composition 300, the decrease in bonding strength due to the decrease in fluidity due to cooling is suppressed.

In the present embodiment, each convex portion 620 has, as side surfaces, a first surface 622 facing upstream with respect to the flow direction and a second surface 624 facing downstream with respect to the flow direction. Such a convex portion 620 contracts so as to tighten the first surface 622 and the second surface 624 more firmly when the resin composition 300 injected and in contact with the metal member 600 is cooled and contracts. The bonding strength between the metal member 600 and the resin composition 300 can be further increased.

Also in this embodiment, the bonding strength between the metal member and the resin composition can be increased even when the thickness of the metal member is particularly large.

Further, in the present embodiment, since the area of the convex portion to be tightened when cooling and shrinking can be increased, the bonding strength between the metal member and the resin composition can be further increased.

The plurality of convex portions 620 may be parallel to each other, or may be non-parallel and extend in a direction deviating from each other.

[Third Embodiment]
FIG. 7 is a schematic perspective view showing a metal member for joining with a resin composition according to a third embodiment.

As shown in FIG. 7, the metal member 700 is a plate-shaped member and has a convex portion 720 arranged on one surface 710. One surface 710 is a surface to which the resin composition is bonded. This embodiment differs from the second embodiment only in the shape of the convex portion 720. Therefore, only the differences from the second embodiment will be described, and the description of the overlapping parts will be omitted.

In the present embodiment, the convex portions 720 include a plurality of rod-shaped first convex portions 720a, first convex portions 720b, first convex portions 720c, and first convex portions 720d, all of which are arranged on the surface of the metal member 700. , Each of which connects these convex portions has a rod-shaped second convex portion 730a, a second convex portion 730b, a second convex portion 730c, and a second convex portion 730d.

The rod-shaped first convex portion 720a, first convex portion 720b, first convex portion 720c, and first convex portion 720d come into contact with the metal member 700 at the time of joining and flow along the surface 710. It is arranged along the surface 710 so as to extend in a direction different from the direction (in the direction of the white arrow in FIG. 7). In the present embodiment, the first convex portion 720a, the first convex portion 720b, the first convex portion 720c, and the first convex portion 720d are all in the direction orthogonal to the flow direction (in FIG. 7, the direction of the shaded arrow). They are spaced apart from each other so that they extend along.

The plurality of first convex portions 720a, first convex portion 720b, first convex portion 720c, and first convex portion 720d flow directions along the flow direction of the resin composition 300 (in the direction of the white arrow in FIG. 7). The shape and arrangement are such that the width of the convex portion to the arrow gradually decreases (the cross-sectional area of the cross section along the distribution direction gradually decreases). Specifically, with respect to the first convex portion 720a arranged on the upstream side with respect to the flow direction, the first convex portion 720b arranged on the downstream side with respect to the flow direction from the first convex portion 720a is the convex portion. It is a convex part with a smaller width. Similarly, the first convex portion 720c arranged on the downstream side of the first convex portion 720b in the flow direction with respect to the first convex portion 720b is a convex portion having a smaller width of the convex portion. The first convex portion 720d arranged on the downstream side of the first convex portion 720c in the flow direction with respect to the first convex portion 720c is a convex portion having a smaller width of the convex portion.

The rod-shaped second convex portion 730a, second convex portion 730b, second convex portion 730c, and second convex portion 730d are in different directions from the direction in which the first convex portion extends (in FIG. 7, arrows with diagonal lines). It is arranged along the surface 710 so as to extend in the direction). In the present embodiment, the second convex portion 730a, the second convex portion 730b, the second convex portion 730c, and the second convex portion 730d are all arranged at intervals so as to extend in the same direction. There is.

The plurality of second convex portions 730a, second convex portion 730b, second convex portion 730c, and second convex portion 730d all have the same width (width in the direction of the shaded arrow in FIG. 7) and are the same. They are arranged at intervals. The shape and arrangement of each of the second convex portions is not limited to these, and the width of the second convex portion may be narrower toward the downstream side with respect to the flow direction, for example.

Also in the present embodiment, the first convex portion 720c and the first convex portion 720d, which are arranged on the downstream side of the resin composition 300 in the flow direction and come into contact with the resin composition 300 whose temperature has decreased, are on the upstream side. The width of the convex portion in the distribution direction (cross-sectional area of the cross section along the distribution direction) is made smaller than that of the arranged first convex portion 720a and the first convex portion 720b. As a result, in the metal member 700, the amount of heat taken by the first convex portion 720c and the first convex portion 720d is reduced while increasing the bonding strength of the resin composition 300 by retaining heat in each of the first convex portions. As a result, the decrease in joint strength due to the decrease in fluidity due to cooling of the resin composition 300 on the downstream side with respect to the flow direction is suppressed.

Further, in the present embodiment, the first convex portion 720a, the first convex portion 720b, the first convex portion 720c, and the first convex portion 720d are the first surface 722 facing upstream with respect to the flow direction and the flow direction. It has a second surface 724 facing downstream with respect to. When the resin composition 300 that has been injected and is in contact with the metal member 700 is cooled and contracted, such a convex portion 720 contracts so that the first surface 722 and the second surface 724 are tightened more firmly. The bonding strength between the metal member 700 and the resin composition 300 can be further increased.

The plurality of second convex portions 730 may be parallel to each other, or may be non-parallel and extend in a direction deviating from each other. Further, the plurality of second convex portions 730 may extend in the same direction as the flow direction, or may extend in different directions with respect to the flow direction.

Further, the height of the plurality of second convex portions 730 from the surface of the metal member 700 (hereinafter, also simply referred to as “height”) may be the same as that of the plurality of first convex portions, or the first It may be different from the convex part. Further, the height may be different between the convex portions of the plurality of second convex portions, and similarly, the height may be different between the convex portions of the plurality of first convex portions.

Further, in the present embodiment, when the resin composition 300 injected and in contact with the metal member 700 is cooled and contracts, the resin composition can be firmly contracted so as to also tighten the second convex portion 730, so that the metal member 700 and the resin composition can be contracted. The bonding strength with the object 300 can be further increased.

[Fourth Embodiment]
FIG. 8 is a schematic perspective view showing a metal member for joining with a resin composition according to a fourth embodiment.

As shown in FIG. 8, the metal member 800 is a plate-shaped member and has a plurality of convex portions 820 arranged on one surface 810. One surface 810 is a surface to which the resin composition is bonded. This embodiment differs from the first embodiment only in the shape of the convex portion 820. Therefore, only the differences from the first embodiment will be described, and the description of the overlapping parts will be omitted.

In the present embodiment, the plurality of convex portions 820 are a plurality of tubular protrusions that are independently arranged on the surface of the metal member 800.

The plurality of convex portions 820 are in contact with the metal member 800 at the time of joining and flow along the surface 810 in the flow direction (the directions of the plurality of white arrows in FIG. 8; hereinafter, also simply referred to as “flow direction”. The shape and arrangement are such that the volume gradually decreases (the cross-sectional area of the cross section along the flow direction gradually decreases) along the.).

Specifically, the plurality of convex portions 820 are arranged radially with respect to the convex portions 820a arranged at the position closest to the point P where the resin composition 300 first contacts in the mold 200 and the point P. It also has a convex portion 820b, a convex portion 820c, and a convex portion 820d having a smaller volume. The convex portion 820b, the convex portion 820c, and the convex portion 820d are shaped and arranged so that the volume becomes smaller as the distance from the point P increases.

Also in the present embodiment, the convex portion 820c and the convex portion 820d arranged on the downstream side with respect to the flow direction of the resin composition 300 and coming into contact with the resin composition 300 whose temperature has decreased are the convex portions arranged on the upstream side. The volume flow (cross-sectional area of the cross section along the flow direction) is made smaller than that of the portion 820a and the convex portion 820b. As a result, the metal member 800 increases the bonding strength of the resin composition 300 by retaining heat in each of the convex portions 820, and reduces the amount of heat taken by the convex portions 820b and the convex portion 820c in the flow direction. On the downstream side of the resin composition 300, the decrease in bonding strength due to the decrease in fluidity due to cooling is suppressed.

Therefore, also in the present embodiment, the bonding strength between the metal member and the resin composition can be increased even when the thickness of the metal member is particularly large.

In the present embodiment, a plurality of independent tubular convex portions 820 are arranged radially, but each convex portion may be an annular protrusion centered on the point P. , The annular protrusion may have notches formed at different positions.

[Fifth Embodiment]
FIG. 9 shows a state of the metal member 900 for joining with the resin composition and the resin composition 300 which is injected into the mold and is in contact with the metal member 900 and is flowing according to the fifth embodiment. It is a schematic diagram which shows.

In the present embodiment, the convex portion 920 is punched from the surface 912 on the side opposite to the surface 910 in contact with the resin composition of the metal member 900, and has a hollow portion 922 inside.

According to the present embodiment, since the convex portion 920 has a hollow portion 922 filled with a heat insulating atmosphere inside the convex portion 920, the heat retaining effect of the convex portion 920 is enhanced. Therefore, the resin composition 300 around the convex portion 920 is hard to be cooled, the generation of voids due to the decrease in fluidity is suppressed more remarkably, and the bonding strength between the metal member 900 and the resin composition 300 is further increased.

The convex portion 920 may be any of the protrusions described in the first to fourth embodiments. Further, all the convex portions 920 included in the metal member 900 may have the hollow portion 922, or only a part of the convex portions 920 may have the hollow portion 922. For example, no cavity is provided in the protrusion on the upstream side in the flow direction in which the temperature of the resin composition is likely to decrease, and the cavity 922 is provided only in the convex portion 920 on the downstream side in the flow direction in which the temperature of the resin composition tends to decrease. It may be provided.

Further, the inside of the cavity portion 922 may be filled with air, may be in a vacuum, or may be filled with a liquid having low heat transfer property.

Further, the cavity portion 922 may be formed by a known method other than punching.

[Other Embodiments]
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

For example, in the first embodiment described above, the example in which the plurality of convex portions are cylindrical having a single side surface has been described, but the first embodiment has the same side surface as in the second embodiment such as a prismatic shape. It may be a convex portion having a shape having a surface and a second surface.

Further, it is preferable to make the plurality of convex portions into a reverse taper shape from the viewpoint of increasing the bonding strength between the metal member and the resin composition.

Further, in each of the above-described embodiments, the example in which the metal member has a plate shape has been described, but the metal member may have any shape other than the plate shape. Further, the convex portion may be arranged only on one surface of the metal member, or may be arranged on a plurality of surfaces to which the resin composition is bonded. Further, the surface on which the convex portion is arranged may be a flat surface or a surface other than a flat surface such as a curved surface.

Further, in each of the above-described embodiments, the example of injecting the molten resin composition into the mold from one gate has been described, but the molten resin composition may be injected from a plurality of gates into the inside of the mold. .. At this time, the volume or width (cross-sectional area of the cross section along the flow direction) of the metal member changes according to the distance from each gate within the range reached by the resin composition injected from each gate. It suffices to have a plurality of convex portions.

Further, the metal member may have two protrusions having different volumes or widths (cross-sectional area of the cross section along the flow direction), but each has a different volume or width (cross-sectional area of the cross section along the flow direction) 3. It is preferable to have one or more protrusions.

Further, the metal member may have micro-concavities and convexities on the order of nanometer to micrometer formed by a method such as laser processing, blasting treatment and chemical treatment. In particular, in the present disclosure, since the convex portion is provided on the surface of the metal member, the fluidity of the resin composition around the convex portion is unlikely to decrease. Therefore, the resin composition easily penetrates into the micro-concavities and convexities, and the bonding strength between the metal member forming the micro-concavities and the resin composition is also likely to be increased.

According to the present disclosure, the bonding strength between the metal member and the resin composition can be further increased. In particular, even when the thickness of the metal member is large, the bonding strength can be further increased, so that it is expected that the use of the metal resin bonded body will be expanded.

100, 600, 700, 800, 900 Metal members 110, 610, 710, 810, 910 Surface 120, 120a, 120b, 120c, 120d, 620, 620a, 620b, 620c, 720, 820, 820a, 820b, 820c, 820d , 920 Convex part 200 type 210 Cavity 220 Core 230 Gate 300 Resin composition 310 Reinforcing fiber 400 Metal resin joint 410 Injection marks 622, 722 First surface 624, 724 Second surface 720a, 720b, 720c, 720d First convex part 730, 730a, 730b, 730c, 730d Second convex part 912 Surface 922 Cavity part

Claims (10)

A metal member for joining with a resin composition.
A plurality of convex portions having different cross-sectional areas along the flow direction of the resin composition that flow in contact with the metal member at the time of joining, all of which project from the surface to which the resin composition of the metal member is joined. Have,
The plurality of convex portions are arranged so that the cross-sectional area of the cross section along the flow direction becomes smaller toward the downstream side with respect to the flow direction.
A metal member for joining with a resin composition. The metal member for joining with the resin composition according to claim 1, wherein the plurality of convex portions are a plurality of tubular protrusions arranged independently of each other. The metal member for joining with the resin composition according to claim 1, wherein the plurality of convex portions are a plurality of rod-shaped protrusions arranged so as to extend in a direction different from the flow direction. The resin composition according to any one of claims 1 to 3, which has rod-shaped protrusions that connect the plurality of protrusions and are arranged so as to extend in the flow direction or in a direction different from the flow direction. A metal member for joining with an object. The plurality of convex portions include a first surface in which at least one convex portion faces the upstream side in the flow direction and a second surface different from the first surface in which the convex portion faces the downstream side in the flow direction. A metal member for joining with the resin composition according to any one of claims 1 to 4. The metal member for joining with the resin composition according to any one of claims 1 to 5, wherein the plurality of convex portions have a hollow portion inside. The process of arranging the metal member inside the mold and
It has a step of injecting a resin composition into a mold in which the metal member is arranged.
The arranged metal member has a plurality of convex portions having different cross-sectional shapes along the flow direction of the injected resin composition on the surface in contact with the injected resin composition.
The plurality of convex portions are arranged so that the cross-sectional area of the cross section along the flow direction becomes smaller toward the downstream side with respect to the flow direction.
A method for manufacturing a metal resin bonded body. A metal-resin bonded body comprising a metal member and a resin composition bonded to the surface of the metal member.
The metal member has a plurality of convex portions having different cross-sectional areas in cross sections along the flow direction of the resin composition that flowed in contact with the metal member at the time of joining on the surface to which the resin composition was joined.
The plurality of convex portions are arranged so that the cross-sectional area of the cross section along the flow direction becomes smaller toward the downstream side with respect to the flow direction.
Metal resin joint. The resin composition has injection marks and has injection marks.
The flow direction is a direction away from the injection mark.
The metal-resin bonded body according to claim 8. The resin composition is a fiber-reinforced resin composition containing reinforcing fibers.
The flow direction is the direction in which the reinforcing fibers are oriented.
The metal resin joint according to claim 8 or 9.

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