JP2010017900A - Method of manufacturing jointed material and injection molding apparatus - Google Patents

Abstract

An object of the present invention is to provide a method for producing a joined body of a resin and a magnesium alloy and an injection molding apparatus capable of achieving both molding and joining of the magnesium alloy even if the resin has a low softening temperature.
A lower mold 3 on which a magnesium alloy 30 on which a film of molecular adhesive is formed is installed, and an upper mold on which a resin 10 is molded in a state of being clamped to the lower mold 3 on which the magnesium alloy 30 is installed. The mold 2 is set to a different temperature, and the molded resin 31 and the joined body 32 of the magnesium alloy 30 are manufactured. Even if the resin 10 having a low softening temperature is set by setting the mold temperature necessary for joining the resin 10 and the magnesium alloy 30 with the molecular adhesive higher than the mold temperature necessary for molding the resin 10, The integral molding that achieves both the joining with the magnesium alloy 30 can be realized.
[Selection] Figure 3

Description

  The present invention relates to a method for manufacturing a joined body of a resin and a magnesium alloy and an injection molding apparatus, which are mainly used for a housing for electronic equipment.

In recent years, mobiles such as mobile phones have been miniaturized with high functionality. However, since the number of components to be mounted increases with the increase in functionality, and the batteries for supplying power to these components are also increasing in size, there has been a situation where weight reduction has not necessarily progressed. Therefore, the weight reduction of the housing that accounts for a large proportion of the total product weight has become an important issue, and high-strength light metals are attracting attention as materials for the housing. Under such a background, a method of manufacturing a housing in which a light metal and a resin are composite-molded has been proposed (see Patent Document 1).
JP 7-124995 A

  In this manufacturing method, a light metal surface-treated with triazine thiols is placed in a mold, and a resin injected into the mold and the light metal are chemically bonded to form a composite. If the light metal is an aluminum alloy, a resin having a low softening temperature such as ABS resin can be joined by injection molding. However, when a magnesium alloy is used, a temperature higher than the mold temperature during normal molding is required. For this reason, if the mold temperature is higher than the mold temperature at the time of normal molding, in the case of a resin with a low softening temperature, it may burn into the mold or cause molding defects due to liquefaction. Possible resins were limited to those with a high softening temperature.

  It is an object of the present invention to provide a method for manufacturing a joined body of a resin and a magnesium alloy and an injection molding apparatus capable of achieving both molding and joining of the magnesium alloy even if the resin has a low softening temperature. .

  In order to solve the above problems and achieve the object, the present invention provides a first mold for installing a magnesium alloy on which a film of molecular adhesive is formed, and the first mold on which the magnesium alloy is installed. The mold and the second mold that molds the resin in a clamped state are set to different temperatures, and the joined body of the molded resin and the magnesium alloy is manufactured.

  Further, a first mold for installing a magnesium alloy on which a film of molecular adhesive is formed, and the first mold and the first mold are clamped, and the magnesium alloy and the cavity installed in the first mold are Injection having a second mold for molding a resin injected into a space formed therebetween, and a temperature control device for independently adjusting the temperatures of the first mold and the second mold A molding apparatus was used.

  By setting the mold temperature required for bonding resin and magnesium alloy with molecular adhesives and the mold temperature required for resin molding to different temperatures, molding and magnesium alloy can be performed even for resins with low softening temperatures. It is possible to achieve integral molding that achieves both joints with.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic view of an injection molding apparatus according to an embodiment of the present invention, FIG. 2 is a schematic view of a resin / magnesium alloy joined body according to the embodiment of the present invention, and FIG. 3 is a schematic view of a resin according to the embodiment of the present invention. It is a manufacturing-process figure of the joined body of a magnesium alloy.

  First, the configuration and function of the injection molding apparatus according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. The injection molding apparatus 1 adjusts the temperature of an upper mold 2 and a lower mold 3 that are divided into upper and lower parts, a lifting device 4 that raises and lowers the lower mold 3, and a heat medium 5 that is built in the upper mold 2. The upper mold temperature control device 6 to be performed, the lower mold temperature control device 8 to adjust the temperature of the heat medium 7 incorporated in the lower mold 3, and the molten resin 10 are injected into the cavity 9 of the upper mold 2. The injection device 11 is configured. The lower mold 3 is formed with a recess 12 for placing a magnesium alloy. The upper die 2 is provided with a heat insulating material 13 in the region excluding the opening edge of the cavity 9 on the lower surface of the upper die 2 and the region excluding the concave portion 12 on the upper surface of the lower die 3, and can be controlled independently. The structure is such that heat transfer between the lower mold 3 and the lower mold 3 is suppressed as much as possible. Accordingly, it is possible to more advantageously perform the control at a desired temperature by suppressing the temperature change of the two molds at the time of mold clamping. Instead of the heat insulating material 13, the inside of these regions can be made hollow so that the thermal conductivity can be reduced.

  The injection device 11 includes an injection cylinder 20 that contains the molten resin 10, a screw 21 that sends the molten resin 10 contained in the injection cylinder 20 to the cavity 9, a screw drive device 22 that supplies driving force to the screw 21, A hopper 23 is provided for supplying molten resin 10 to the injection cylinder 20 from the outside. The injection cylinder 20 is provided with a heater 24 for heating so that the built-in molten resin 10 is not cured.

  FIG. 2 shows a joined body of a resin molded product and a magnesium alloy manufactured by the injection molding apparatus 1. The resin molded product and the magnesium alloy are bonded using a triazine thiol derivative. A triazine thiol derivative is a molecular adhesive having a property of being strongly chemically bonded to a polymer compound such as a resin or a metal. Examples include triethoxysilylpropylaminotriazine thiol and 2,4,6-trimercapto-s-triazine monosodium salt.

  The lower mold 3 of the injection molding apparatus 1 is a first mold on which a magnesium alloy having a surface formed with a triazine thiol film in advance by dipping or electrolytic polymerization is placed. This is a second mold that forms a resin molding space between the cavity 9 and the magnesium alloy while being clamped to the mold 3. Molten resin 10 injected into the cavity 9 from the upper mold 2 side with the upper mold 2 and the lower mold 3 clamped is solidified and molded in the resin molding space, and the molecular adhesion possessed by the triazine thiol derivative Joins with magnesium alloy due to its function as an agent.

  Next, the manufacturing process of the joined body of resin and magnesium alloy will be described with reference to FIG. First, the magnesium alloy 30 on which the triazine thiol film is formed is placed in the recess of the lower mold 3. The upper surface of the magnesium alloy 30 placed in the recess is on the same plane as the upper surface of the lower mold 3 so that it can come into flat contact with the lower surface of the upper mold 2 during clamping. Thereafter, the lower surface of the upper mold 2 and the upper surface of the lower mold 3 are brought into close contact with each other by mold clamping. As a result, a resin molding space 40 is formed between the cavity of the upper mold 2 and the magnesium alloy 30 placed on the lower mold 3.

  Then, the molten resin 10 is injected from the upper mold 2 side to fill the resin molding space 40. The molten resin 10 filled in the resin molding space 40 is solidified following the shape of the space, and the lower end portion in contact with the magnesium alloy 30 is joined to the magnesium alloy 30 by the molecular adhesive force of the triazine thiol coating.

  After a predetermined time has elapsed since the resin injection, the upper mold 2 and the lower mold 3 are separated by mold opening. At this time, the molten resin 10 is solidified to form a resin molded product 31, and the lower end portion thereof is joined to the magnesium alloy 30. Therefore, when the mold is opened, the resin molded product 31 follows either the upper mold 2 or comes off from the upper mold 2 and follows the lower mold 3 together with the magnesium alloy 30. The upper mold 2 is followed for the reason to do. Finally, the resin molded product 31 is extracted from the upper mold 2 to complete a joined body 32 in which the resin molded product 31 and the magnesium alloy 30 are joined.

  Next, temperature management of the upper mold 2 and the lower mold 3 will be described with reference to (Table 1). (Table 1) shows the temperature of upper and lower molds when ABS resin (acrylonitrile-butadiene-styrene resin) is used as the resin integrally molded with the magnesium alloy, the bonding state between the resin molded product and the magnesium alloy, and the resin molding. This represents the quality relationship with the product. In general, the mold temperature when an ABS resin is injection-molded alone is set between 40 degrees and 80 degrees. Therefore, in the manufacturing process shown in FIG. 3, when the upper and lower molds were set to 60 degrees, the quality of the resin molded product 31 was good, but the magnesium alloy 30 was hardly joined. Similar results were obtained when the upper and lower molds were raised to 80 degrees. In addition, in the aluminum alloy in which the conventional triazine thiol film was formed, it was joined with the ABS resin at a mold temperature of 80 degrees.

  This time, the upper mold 2 and the lower mold 3 are changed to independent temperature control, and only the lower mold 3 on which the magnesium alloy 30 is placed is raised to 180 degrees. As a result, the upper mold set to 60 degrees is set. The quality of the resin molded product 31 molded by the mold 2 was good, and bonding with the magnesium alloy 30 was recognized although the strength was insufficient. When the temperature of the lower mold 3 was further increased to 200 degrees, it was confirmed that the resin molded product 31 and the magnesium alloy 30 were joined with sufficient strength. By the way, when the upper and lower molds were set to 200 degrees, the bonding between the resin and the magnesium alloy 30 was recognized, but the resin was not molded into a shape following the shape of the cavity 9, and part of the resin was burnt. It was happening.

  From this result, when manufacturing a joined body in which a resin and a magnesium alloy 30 formed with a triazine thiol film are integrally formed using a mold, the upper mold 2 for molding the molten resin 10 and the magnesium alloy 30 are obtained. It is preferable that the temperature control of the lower mold 3 to be placed is performed independently, and the temperature control is performed so that the lower mold 3 has a higher temperature (200 degrees or more) than the upper mold 2.

  As described above, since the set temperature is greatly different between the upper mold 2 and the lower mold 3, the joined body 32 follows the upper mold 2 having a low set temperature when the mold is opened. The cooling rate is increased by separating from the mold 3.

  Further, as described above, since the heat insulating material 13 is provided in the region excluding the concave portion 12 on the upper surface of the lower mold 3, it becomes difficult for heat to be transmitted to the upper mold 2 having a low set temperature. It becomes easy to control each temperature of the mold 2 and the lower mold 3.

  The resin to be bonded to the magnesium alloy is not limited to the ABS resin described above, and the types of the actually bonded resin and the mold temperature set at that time are shown in (Table 2).

  In addition to ABS resin, for PBT (Polybutylene Tephthalate), PPS (Polyphenylene Sulfide), and polyamide, by controlling the upper and lower molds at the set temperatures shown in (Table 2), each resin molding and triazine thiol derivative Bonding with the magnesium alloy was performed well. Here, the temperature range of the upper mold is equivalent to the mold temperature during normal molding for each resin. The temperature range of the lower mold temperature is preferably equal to or higher than the mold temperature at the time of joining the magnesium alloy on which the triazine thiol film is formed and each resin, and is equal to or lower than the plasticizing temperature of each resin.

  Note that the temperature of the upper mold 2 is a general temperature at the time of resin molding, and varies depending on the shape of the resin to be molded and is not limited to the above temperature range.

  The method for producing a resin / magnesium alloy joined body and an injection molding apparatus according to the present invention include a mold temperature required for joining a resin and a magnesium alloy with a molecular adhesive, and a mold temperature required for molding the resin at different temperatures. By setting to, even with a resin having a low softening temperature, it is possible to realize integral molding that achieves both molding and joining of a magnesium alloy. As a result, it can be used as a housing for electronic devices such as mobile phones and personal computers.

Schematic of an injection molding apparatus according to an embodiment of the present invention Schematic of a bonded body of resin and magnesium alloy according to an embodiment of the present invention Manufacturing process diagram of bonded body of resin and magnesium alloy according to the embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection molding apparatus 2 Upper mold 3 Lower mold 6 Upper mold temperature control apparatus 8 Lower mold temperature control apparatus 30 Magnesium alloy 31 Resin molding product 32 Joint body

Claims (8)

A first mold for installing a magnesium alloy containing at least magnesium on which a film of molecular adhesive is formed, and a first mold for molding a resin in a state of being clamped to the first mold on which the magnesium alloy is installed The manufacturing method of the joined body which sets the metal mold | die of 2 to different temperature, respectively, and manufactures the molded object of the said molded resin and the said magnesium alloy. The method for manufacturing a joined body according to claim 1, wherein the temperature of the first mold is set higher than the temperature of the second mold. The method for manufacturing a joined body according to claim 2, wherein the temperature of the first mold is equal to or higher than a temperature at which the resin and the magnesium alloy are bonded. The method for manufacturing a joined body according to claim 2, wherein the temperature of the first mold is 200 degrees or more. 2. The method for manufacturing a joined body according to claim 1, wherein the first mold and the second mold have a heat insulating material or a hollow portion on a surface that contacts when the mold is clamped. A first mold for installing a magnesium alloy on which a film of molecular adhesive is formed, and the first mold and the mold are clamped, and between the magnesium alloy and the cavity installed in the first mold An injection molding apparatus provided with a second mold for molding the resin injected into the formed space, and a temperature control device for independently adjusting the temperatures of the first mold and the second mold . 7. The injection molding apparatus according to claim 6, wherein the temperature control device of the first mold can be set to 200 degrees or more. The said 1st metal mold | die and a 2nd metal mold | die are the injection molding apparatuses of Claim 6 which has a heat insulating material or the hollow part in the surface which contacts at the time of mold clamping.

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