JP2009051131A - Composite body of metal and resin, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite body of metal and resin which has a desired joining strength, and to provide a method of manufacturing the composite body. <P>SOLUTION: The composite body of metal and resin is a composite body 10 for which a melted resin composition is jetted onto the surface of a metallic base material and integrated into one unit. The metallic base material 12 is provided on the surface with a plurality of inclined holes 16 the axial lines L of which are inclined at a prescribed angle α to the perpendicular H of the surface of the metallic base material. The resin composition 14 is integrally provided with resin projections 14b of the resin composition that is filled in the inclined holes 16, wherein the metallic base material 12 and the resin composition 14 are firmly joined through a mechanical anchor effect of the resin projections 14b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a composite of metal and resin and a method for producing the same. Specifically, the present invention relates to a metal / resin composite integrated by injection molding and a method for manufacturing the same.

  As a technology that integrates metal and resin, a fine recess is formed on the metal surface by etching or sandpaper polishing, and the metal and resin are joined by a mechanical anchor effect by filling the recess with molten resin. Things have been done.

  However, this method has a problem in that it is difficult to control the shape, depth, number, and the like of the formed recesses, so that the bonding strength is small and the variation tends to be large. Therefore, the desired bonding strength cannot be stably guaranteed.

  Patent Document 1 discloses a technique in which an anchor lock portion is formed on a metal surface, and a molten resin is solidified and integrated around the anchor lock portion.

However, in this method, since it is necessary to project the anchor lock portion on the metal surface, a great number of processing steps are required, and the productivity is inferior.
JP 2006-341515 A

  The present invention is intended to solve the above-described problems, and provides a composite of a metal and a resin having a desired bonding strength and a method for producing the same.

  The composite of metal and resin of the present invention is a composite of metal and resin that is integrated by injecting a molten resin composition onto the surface of the metal substrate, and the metal substrate has an axis line on the surface of the metal substrate. Has a plurality of inclined holes inclined at a predetermined angle with respect to the normal to the surface of the metal substrate, and the resin composition integrally has resin convex portions of the resin composition filled in the inclined holes. It is characterized by that.

  In the metal / resin composite of the present invention, it is desirable that the inclined hole is composed of a plurality of inclined hole groups having different inclination directions, and the inclined holes are in communication with each other at the tip of the inclined hole. Also good.

  In the metal / resin composite of the present invention, an adhesive may be further provided on the inner peripheral surface of the inclined hole.

  In the method for producing a composite of a metal and a resin according to the present invention, an inclined hole whose axis is inclined at a predetermined angle with respect to a normal to the surface of the metal base is formed on the surface of the metal base processed into a predetermined shape An inclined hole forming step, an insert step of inserting the metal base material having the inclined hole into the injection mold, and a resin composition melted in the injection mold for integration with the inserted metal base material. An injection step of injecting, and integrating the metal substrate and the resin composition.

  In such a method for producing a composite of metal and resin according to the present invention, the inclined hole forming step includes at least one of electric discharge machining, laser spot irradiation machining, drill cutting machining, or plastic machining. Is desirable.

  Since the resin convex part integrally formed in the resin composition is formed by entering the metal base material at an angle, the metal / resin composite of the present invention has a mechanical anchor effect of the resin convex part. It has a stronger and stable bonding strength. And since the magnitude | size of this resin convex part, a number, a distribution form, etc. can be managed as a design matter, desired joining intensity | strength can be ensured.

  In addition, by forming the inclined hole with a plurality of inclined hole groups having different inclination directions, the directionality of the bonding strength is lost, and a composite having more stable bonding strength can be obtained. Furthermore, when the inclined holes communicate with each other at the tip of the inclined hole, or when an adhesive is provided on the inner peripheral surface of the inclined hole, the resin convex portion of the resin composition formed in the inclined hole is easily formed from the inclined hole. It is possible to guarantee a high bonding strength.

  According to the method for producing a composite of a metal and a resin of the present invention, it is only necessary to add an inclined hole forming step for forming an inclined hole in a metal base before conventional insert molding, so that the conventional line needs to be significantly changed. And there is no reduction in productivity. Further, according to the present invention, a metal / resin composite having a desired bonding strength can be obtained regardless of the combination of any metal material and resin material.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 schematically shows a cross section of the composite of the present invention. The composite 10 is a joined body in which the resin composition 14 is joined to the metal base 12. The resin composition 14 is integrally formed with the resin main body 14 a laminated on the surface of the metal base 12 and the resin main body 14 a. It consists of a plurality of resin protrusions 14 b that are formed and held in the metal substrate 12. The resin convex portion 14b is formed integrally with the resin main body 14a by filling the plurality of inclined holes 16 provided on the surface of the metal base 12 with the molten resin composition and cooling.

  The inclined hole 16 is formed such that the axis L thereof is inclined at a predetermined angle α with respect to the normal H on the surface of the metal substrate 12. For this reason, the resin main body 14a is firmly joined to the metal substrate 12 by the mechanical anchor effect of the resin convex portion 14b that is integrally formed and held in the metal substrate 12.

  Here, the inclined hole 16 may be appropriately formed depending on the shape of the resin main body 14a, the strength of the resin material, the location where the metal substrate 12 is drilled, etc., but the opening diameter d is approximately 0.05 to 1 mm and the depth h. Is preferably about 0.5 to 5 mm. If the opening diameter d is less than 0.05 mm, the molten resin cannot be reliably filled. On the other hand, holes larger than 1 mm are not desirable because they may reduce the strength of the metal substrate. It is desirable that the depth h is appropriately selected in relation to the opening diameter d, and h / d is preferably about 3 to 20. If h / d is less than 3, the resin protrusion 14b may come out of the inclined hole 16 depending on the direction of the load acting on the resin main body 14a and the inclination angle α, while the deep hole exceeding 20 is the thickness of the metal substrate. This is not appropriate because there are problems such as restrictions due to height and restrictions due to the formation method. As for h / d, 5-10 are more preferable.

  Moreover, in order to ensure the anchor effect of the resin convex part 14b, it is desirable that the inclination angle α is less than 90 ° and as large as possible. However, considering the size of the inclined hole and the ease of formation thereof, 20 to 60 ° is appropriate. More preferably, it is 30-50 degrees.

  By the way, the bonding strength in the direction of the axis L of the inclined hole 16 is only the fitting force between the resin convex portion 14b and the inclined hole 16, so that if all the inclined holes 16 are formed in the same direction at the same angle α, the resin convexity The anchor effect of the part 14b cannot be expected. Therefore, it is desirable that the inclined hole 16 is configured as a plurality of inclined hole groups having different inclination directions. The composite 10 shown in FIG. 1 is composed of an inclined hole group of an inclined hole 16a having an inclination angle of -α and an inclined hole 16b having a + α with respect to the perpendicular H on the surface of the metal substrate 12. By comprising in this way, joining of the metal base material 12 and the resin composition 14 can be made more reliable. In addition, as shown in FIG. 2, it is also preferable to form an anchor 14 c in which inclined holes 16 c and 16 d having different inclination directions are formed to communicate with each other at the tip, and resin convex portions are integrated. By providing a large number of such integrated anchors 14c, the anchor 14c does not come out of the inclined hole 16 regardless of the direction of the load acting on the resin main body 14a and the inclination angle of the inclined hole 16. Therefore, it can be set as the composite which has stronger joint strength. Furthermore, if a urethane resin or an epoxy adhesive is applied to the surface of the metal base 12 or the inner surface of the inclined hole and then the molten resin is filled, the adhesive adheres to the fitting force between the resin convex portion 14 b and the inclined hole 16. Since force is added, an even stronger bonding strength can be obtained.

  As described above, in the present invention, the bonding strength between the resin and the metal is increased by the mechanical anchor effect of the resin convex portion 14b formed by filling the inclined hole 16 formed on the surface of the metal base 12 with the molten resin. Trying to get. The size of the inclined hole 16 (opening diameter d, depth h), the inclination angle α, the number, the distribution form on the joint surface, and the like can be set as design items in advance. Therefore, according to the present invention, it is possible to design a composite 10 of a resin and a metal having a desired bonding strength.

  The composite 10 of the present invention having the above configuration can be obtained as follows.

  First, a predetermined metal material is formed to obtain a metal substrate having a desired shape. There is no particular limitation on the metal material, and a metal material that is usually used as a housing or a part of an electronic device or a household electrical appliance, a structural part, a machine part, or the like, such as a light metal such as aluminum, steel, or stainless steel can be applied. These metal materials are subjected to well-known metal processing such as milling, drilling, pressing, grinding, and polishing to obtain a metal base 12 having a shape and structure necessary for inserts in injection molding.

  Next, the inclined hole 16 is formed on the surface of the metal base 12. Prior to drilling the inclined hole 16, as shown in FIG. 3, as a pre-processing, a V-shaped groove (concave portion) 18 having a surface 18 a perpendicular to the axis L of the inclined hole 16 (hereinafter referred to as an inclined surface) is formed. It is good to form in the inclined hole drilling location. By forming such a V-shaped groove 18, the inclined hole 16 can be easily and accurately drilled in the smooth horizontal surface 12 a of the metal substrate 12. For this pre-processing, a known method such as press processing such as coining or cutting processing may be adopted as appropriate at the same time as or after the formation of the metal base 12.

  Subsequently, a desired inclined hole 16 is formed perpendicularly to the inclined surface 18a of the V-shaped groove 18 by any one of electric discharge machining, drill hole machining, press hole machining, or laser machining. At this time, a plurality of inclined holes 16 are formed. At least one of the plurality of inclined holes may be formed so that the inclined direction of the axis is different from the other inclined holes. Further, the size and shape of the inclined holes are not necessarily the same, and may be different for each inclined hole to be formed.

  Thereafter, an adhesive may be applied to the surface of the metal base material having the inclined holes. The adhesive may be spray-coated using a liquid such as urethane or epoxy so that the adhesive sufficiently adheres to the inner peripheral surface of the inclined hole. At this time, it is desirable to adjust the viscosity of the liquid to be low so that the liquid does not block the inclined hole.

  Next, the metal base 12 having a large number of inclined holes 16 is inserted into a predetermined injection mold and the mold is closed, and the cavity formed between the metal base 12 and the injection mold is placed in the cavity. The molten resin composition is injected. There are no particular restrictions on the injection conditions of the molten resin, and it may be carried out under the same conditions as in normal injection molding. However, depending on the type of resin composition to be injected and the size of the inclined hole, the mold temperature, injection temperature or injection pressure may be set slightly higher. This is to increase the fluidity of the molten resin and reliably fill the resin composition into the inclined hole to form the resin protrusion 14b as designed.

  In the present invention, the resin composition used as the molten resin may be a thermoplastic resin composition used in normal injection molding. For example, polyamide (PA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), polyphenyl sulfide (PPS), polycarbonate (PC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene resin ( A polymer such as ABS resin) or polystyrene (PS) or a polymer compound obtained by combining them can be preferably used.

  Moreover, it is also preferable to contain a filler as desired. Examples of fillers include commonly used high-strength fibers such as glass fibers and pulverized products such as talc, but spherical or granular pulverized products such as calcium carbonate, silica, talc, and clay are suitable. By including such a filler, the strength, thermal expansion coefficient, and the like of the resin composition can be adjusted.

  As described above, in the composite material of resin and metal, conventionally, it has not been possible to design the bonding strength to a desired value. However, in the present invention, the size (opening diameter d, depth h), the inclination angle α, the number of the inclined holes 16, the distribution form on the bonding surface, or the like can be set so as to obtain a desired bonding strength. . Hereinafter, the present invention will be described in more detail by showing specific examples of the design.

FIG. 4 is a partial perspective view of a housing such as a mobile phone, and shows a composite 20 in which a resin boss 24 is joined to a metal housing 22. A screw-fixing boss 24 is joined to a flat portion of an aluminum molded body 22 forming a casing by injection molding. Here, an aluminum molded body 22 material is pure aluminum material for _{JISA1050-H 24} molded 1mm thick obtained by the rolling method. The boss 24 is a PBT / PC containing 20% glass fiber and 10% carbon fiber (PBT about 90% + PC about 10%, “Toughpet S” manufactured by Mitsubishi Rayon Co., Ltd.) and integrated with an aluminum molded body. The boss 24 has a truncated cone shape with a bottom surface (joint surface) diameter A: 8 mm, a top surface diameter B: 4 mm, and a height C of 8 mm, and a screw hole with a diameter D: 2 mm and a depth E: 5 mm at the center. In the composite 20 of metal and resin having such a configuration, a measurement end with a thread for torque measurement is screwed into the screw hole 26 to ensure a bonding strength with a torque of 200 Ncm or more.

  An example of the composite 20 designed under the above conditions is shown in FIG. (A) is a top view of a joint surface, (b) is XX sectional drawing.

  On the surface of the aluminum molded body 22, inclined holes 26 having an opening diameter d: 0.3 mm, a depth h: 1.0 mm, and an inclination angle α: 30 ° are equally spaced from the center of the bottom surface of the boss 24 on a circumference of 3 mm Drill twelve. Thereafter, insert molding is performed by a normal method, and “tough pet S” is filled into the inclined hole 26 to form twelve resin convex portions 24b.

  The above is an example, and the number of the resin protrusions may be reduced by increasing the opening diameter d of the inclined holes and making the resin protrusions thicker. You may make a convex part thin and may increase the number of resin convex parts by that much. Such an inclined hole may be formed by a known electric discharge machining method (for example, JP-A-2002-1617).

  The present invention relates to a metal used for a housing of an electronic device, a housing of a household electrical appliance, a structural component, a mechanical component, a structural component for a vehicle, a vehicle-mounted product, a component of a building material, another structural component, an exterior component, and the like. It can be suitably used for a resin composite.

It is a cross-sectional schematic diagram explaining the composite_body | complex of this invention. It is a schematic diagram which shows the cross section of the composite_body | complex obtained by making an inclined hole communicate. It is a schematic sectional drawing of the metal base material explaining the pre-processing of an inclined hole drilling. It is a perspective view which shows the composite_body | complex which joined the resin boss | hub to the metal housing. It is a figure which shows the joining aspect of FIG. 4, (a) is a top view, (b) is AA sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 20: Composite 12: Metal base material 14: Resin composition 14a: Resin main body 14b: Resin convex part 16: Inclined hole 22: Aluminum molded object 22 24: Boss

Claims (7)

A metal-resin composite in which a molten resin composition is injected and integrated on the surface of a metal substrate,
The metal substrate has a plurality of inclined holes whose axis is inclined at a predetermined angle with respect to the normal of the metal substrate surface on the metal substrate surface,
The resin composition has a resin protrusion filled in the inclined hole, and is a composite of metal and resin.   The metal / resin composite according to claim 1, wherein the inclined hole includes a plurality of inclined hole groups having different inclination directions.   The metal / resin composite according to claim 1, wherein the inclined holes communicate with each other at a tip portion of the inclined holes.   The metal / resin composite according to claim 1, further comprising an adhesive on an inner peripheral surface of the inclined hole. An inclined hole forming step of forming an inclined hole on the surface of the metal base material processed into a predetermined shape; an insert step of inserting the metal base material formed with the inclined hole into an injection mold;
An injection step of injecting a thermoplastic resin composition into the injection mold for integration with the inserted metal substrate,
A method for producing a composite of a metal and a resin, wherein the metal substrate and the thermoplastic resin composition are integrated.   The method for producing a composite of metal and resin according to claim 5, further comprising an application step of applying an adhesive to the inner peripheral surface of the inclined hole.   The method for producing a composite of metal and resin according to claim 5 or 6, wherein the inclined hole forming step includes any one of electric discharge machining, laser spot irradiation machining, drill cutting machining, or plastic machining.

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