Resin joining method using two-color molding

Abstract

To provide a resin molding mold that can be used for two-color molding to obtain a resin molded product that improves bonding with a resin layer.SOLUTION: A resin molding mold 1 has a protruding member 11 having a large cross-sectional area at a tip formed on at least one surface of a core 1A and a cavity 1B of the resin molding mold.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention is based on two-color molding. Resin bonding method Regarding. [Background technology]

[0002] Patent Document 1 describes a two-color molding method in which a primary molded product made by injection molding black synthetic resin in a mold is placed in a mold (not shown), and a secondary molding material made of gray synthetic resin is injection molded.The method describes providing a groove in the primary molded product whose innermost part is wider than the outlet part, making the primary molded product and the secondary molded product firmly bonded together so that they do not easily peel apart, and the shape of the groove whose innermost part is wider than the outlet part is shown in Figures 4 to 11.

[0003] However, in Patent Document 1, even if the primary molded product is molded using a mold not shown, it is desirable to easily manufacture a mold that molds the primary molded product (the resin molded product of the present application) so that a groove (the recess of the present application) whose innermost part is wider than the outlet part is formed in the primary molded product (the resin molded product of the present application), and to use the resin molded product molded from that mold for two-color molding to improve the bonding of the resin.

[0004] [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 57-189834 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention is used in two-color molding to improve the bonding with the resin layer. Resin bonding method The purpose is to provide. [Means for solving the problem]

[0007] The resin joining method by two-color molding according to claim 1 of the present invention comprises: Made of metalOn at least one surface of the core and cavity Scanning pulsed laser light Large cross-sectional area at the tip Multiple A resin molding die having a protruding member formed thereon is prepared, The core and cavity of the resin molding die are closed, and a space having the plurality of protruding members is formed. Thermoplastic resin is injection molded to Multiple Anchor-shaped by protruding parts Multiple A recess is formed a primary molded article consisting of a resin molded article obtained by the above-mentioned method, and the primary molded article is set in a two-color molding die, and a secondary molding thermoplastic resin is filled into the anchor-shaped recesses, thereby forming a resin layer of the secondary molding thermoplastic resin on the primary molded article; The method is characterized in that a two-color molded product is obtained in which the resin layer of the secondary molding thermoplastic resin is bonded to the resin molded product via the anchor-shaped recess. The resin joining method by two-color molding according to claim 2 of the present invention comprises: The method according to claim 1 In the resin joining method using two-color molding, A pulsed laser beam is scanned on the surface of at least one of the core and cavity of the resin molding die, forming a plurality of protruding members having a large cross-sectional area at the tip on the surface. the pulsed laser light that forms the core and cavity is laser light L, and a scanning requirement of the laser light is to specify a coefficient R expressed by equation (1) consisting of a scanning frequency h of the laser light L, a pulse width t of the laser light L, and a scanning speed v of the laser light L based on the thermal diffusion coefficient of the metal material of the core and cavity, and the laser light L whose coefficient R is 0.1 to 1.0 is irradiated while scanning in a direction along the surface of the core and cavity. R=2h√kt / v...Equation (1) (Here, in equation (1), h is the scanning frequency of the laser light, k in √kt is the thermal diffusion coefficient of the metal material that makes up the cavity and core of the resin molding die, t in √kt is the pulse width of the laser light, and v is the scanning speed of the laser light.) [Effects of the Invention]

[0008] The present invention relates to a resin molding die. Made of metal On at least one surface of the core and cavity Scanning pulsed laser light Large cross-sectional area at the tip Multiple The protruding member is formed A resin molding die is prepared, and a plurality of recesses in the shape of anchors are formed using the resin molding die. Resin molded products are primary molded products By using two-color molding, Secondary molding resin as a resin layer By laminating the secondary molding resin on the primary molding, a two-color molding product is obtained in which the secondary molding resin is bonded to the anchor-shaped recesses, thereby improving the bond between the primary molding and the resin layer of the secondary molding resin in the resin bonding method using two-color molding. It is possible. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing an outline of a resin molding die in which a protrusion member of the present invention is formed. [Figure 2] 1 is a cross-sectional view showing a state in which a protruding member of the present invention is formed on a core of a resin molding die. [Figure 3] 1 is a manufacturing process diagram for manufacturing a resin molded product using a resin molding die of the present invention. [Figure 4] FIG. 2 is a cross-sectional view of the resin molding die of the present invention, showing a state in which the resin molding die is closed and filled with resin for a resin molded product. [Figure 5]1 is a cross-sectional view of a resin molding die of the present invention, which is filled with a resin for a resin molded product, and which is opened with a softened resin molded product held in the die. FIG. [Figure 6] 1 is a cross-sectional view of a resin molding die of the present invention, which is opened to obtain a resin molded product. FIG. [Figure 7] 1 is a cross-sectional view showing a resin molded product obtained by the resin molding die of the present invention. [Figure 8] FIG. 8 is a cross-sectional view of a two-color molding die for obtaining a two-color molded article in which a resin layer is laminated on the resin molded article shown in FIG. [Figure 9] FIG. 9 is a cross-sectional view showing a two-color molded product obtained by the two-color molding die shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Mold for resin molding) FIG. 1 shows a resin molding die on which the protruding members of the present invention are formed.

[0011] In FIG. 1, reference numeral 1 denotes a resin molding die having a core 1A and a cavity 1B. Both the core 1A and the cavity 1B are made of metal, and a plurality of protruding members 11 with large cross-sectional areas at their tips are formed on the surface of the core 1A, and a nozzle hole 12 is formed in the cavity 1B. The core 1A is a movable die that can be moved up and down by a die opening / closing drive device (not shown), while the cavity 1B is a fixed die that cannot move. When the core 1A and the cavity 1B are closed, the resin molding die 1 is in a closed state, and a space 1C is formed. A resin for a resin molded product (a thermoplastic resin is exemplified in this application) is injected from the nozzle hole 12 to fill this space 1C. Furthermore, by closing core 1A and cavity 1B, the tips of protruding members 11 formed on the surface of core 1A are arranged facing cavity 1B in space 1C, but protruding members 11 with larger cross-sectional areas at their tips may be formed on the surface of cavity 1B instead of on the surface of core 1A, or on the surfaces of core 1A and cavity 1B. Furthermore, although the figure shows that multiple protruding members 11 are formed, there may be only one.

[0012] (Formation of protruding members) FIG. 2 shows the state in which the protruding member of the present invention is formed on the core of a resin molding die.

[0013] 2 shows how a pulsed laser beam L is scanned in a direction (X direction) along the surface of a core 1A made of metal, thereby forming a protrusion 11 with a large cross-sectional area at the tip on the surface of the core 1A. The formation of a protrusion 11 with a large cross-sectional area at the tip on the surface of the core 1A is achieved by utilizing a laser beam, which the inventor has been researching. The scanning requirements for this laser beam L, which consist of a scanning frequency h of the pulsed laser beam L, a pulse width t of the laser beam L, and a scanning speed v of the laser beam L, are specified based on the thermal diffusion coefficient of the metal material of the core 1A. By irradiating the core 1A with a pulsed laser beam L that satisfies these scanning requirements while scanning it in a direction along the surface of the core 1A, a protrusion 11 with a large cross-sectional area at the tip is formed on the surface of the core 1A.

[0014] The scanning requirement of the laser beam is determined by the coefficient R expressed by the following formula (1), and the coefficient R is 0.1 to 1.0 By irradiating the core 1A with a pulsed laser beam L that fills the core 1A while scanning it in a direction along the surface of the core 1A, a protruding member 11 having a large cross-sectional area at the tip is formed on the surface of the core 1A. R=2h√kt / v (1) (Here, in equation (1), h is the scanning frequency of the laser light, k in √kt is the thermal diffusion coefficient of the metal material that makes up the cavity and core of the resin molding die, t in √kt is the pulse width of the laser light, and v is the scanning speed of the laser light.)

[0015] In this case, although not shown, instead of the core 1A, pulsed laser light L may be scanned on the cavity 1B of the resin molding die 1 or on the surfaces of the core 1A and cavity 1B according to the scanning requirements specified above to form a protrusion member 11 with a large cross-sectional area at the tip on the surface of the cavity 1B or on the surfaces of the core 1A and cavity 1B.

[0016] (Confirmation of protruding parts formed on resin molding dies) In Equation 1, when the thermal diffusion coefficient k of the metal material of core 1A is 6.61 mm2 / sec, and laser light L is scanned on the surface of core 1A in the X direction with a scanning frequency h of 50 Hz, a scanning speed V of 150 mm / sec, a pulse width t of 100 sec, and a coefficient R of 0.542, protrusion members 11 with large tip cross-sectional areas are formed on the surface of core 1A. However, when laser light L is scanned with the same scanning frequency h and pulse width t but a scanning speed V of 70 mm / sec and a coefficient R of 1.161, protrusion members 11 are formed on the surface of core 1A, but the cross-sectional area of the tip is not large. Furthermore, when laser light L is scanned with a scanning frequency h of 100 Hz, a scanning speed V of 1000 mm / sec, a pulse width t of 27.6 sec, and a coefficient R of 0.085, no protrusion members are formed on the surface of core 1A. In this way, it has been proven that specifying the scanning requirements of the laser light L, consisting of the scanning frequency of the pulsed laser light L, the pulse width of the laser light L, and the scanning speed of the laser light L based on the thermal diffusion coefficient k of the metal material of the core 1A, is an important scanning requirement for forming a protrusion member 11 with a large cross-sectional area at the tip on the surface of the core 1A, and is useful as laser processing.

[0017] (Manufacturing resin molded products using resin molding dies) 3 to 7, the production of a resin molded product using a resin molding die will be described.

[0018] Fig. 3 shows a manufacturing process diagram for manufacturing a resin molded product using a resin molding die. In Fig. 3, the manufacturing process includes a molten resin filling step 91 in which a heated resin molding die 1 is filled with a resin for a resin molded product, a separation step 92 in which the filled molten resin 100A is softened before solidifying in the process of cooling the resin molding die 1 and the softened resin is separated from the protruding member 11 of the core 1A while remaining in the cavity 1B, and a cooling step 93 in which the molten resin 100A remaining in the cavity 1B is solidified and removed from the cavity 1B.

[0019] Figure 4 shows the resin molding die 1 shown in Figure 1 in a closed state, used in molten resin filling step 91. In Figure 4, the resin molding die 1 is an injection molding die having a core 1A made of a metal material and a cavity 1B made of a metal material, as shown in Figure 1, the core 1A is a die that can be moved up and down by a die opening / closing drive device (not shown), the cavity 1B is a fixed die having a nozzle hole 12, and a nozzle 2 is provided on the top surface of the cavity 1B, which injects and fills the resin for a resin molded product through the nozzle hole 12 into a space 1C formed by the core 1A and the cavity 1B. 3 is a holding member that is loosely fitted into the core 1A and can be moved up and down, and its tip is exposed in the space 1C. The core 1A and the cavity 1B are closed, and a protruding member 11 with a large cross-sectional area at its tip is disposed in a space 1C formed by closing the resin molding die 1, the protruding member 11 extending from the surface of the core 1A toward the cavity 1B, and the space 1C is heated by heating the core 1A and the cavity 1B. The resin for the resin molding product is then injected from the nozzle 2 through the nozzle hole 12 into the heated space 1C, filling it and melting it. Thus, in the molten resin filling step 91, the resin for the resin molding product is filled into the heated resin molding die 1 and becomes molten. The material of the resin for the resin molding product may be any resin that melts when filled into the heated resin molding die 1 and softens during the cooling process. Examples of such resins include thermoplastic resins such as polypropylene resin (PP resin), polyacetal resin (POM resin), polyphenylene sulfide resin (PPS resin), polyether ether ketone resin (PEEK resin), acrylonitrile butadiene styrene resin (ABS resin), polyethylene resin (PE resin), polybutylene terephthalate resin (PBT resin), polyamide resins (PA resins) such as nylon 66 (PA66), liquid crystal polymer (LCP resin), modified polyphenylene ether resin (modified PPE resin), and reactor-type flexible polypropylene-based resin (metallocene-based reactor-type TPO resin).These thermoplastic resins may be blended with at least one selected from reinforcing materials such as carbon fiber, glass fiber, and talc, flame retardants, antidegradants, and elastomer components, such as carbon fiber-reinforced thermoplastic resin (CFRTP) blended with carbon fiber.

[0020] 5 shows a resin molding die 1 in which the core 1A and cavity 1B are opened so that the core 1A descends in the direction of the arrow and the softened molten resin 100A is separated from the cavity 1B during the cooling process of the resin molding die 1, which has been heated so that the resin for the resin molded product becomes molten in a separation process 92. In FIG. 5, as the core 1A descends in the direction of the arrow, the softened molten resin 100A is held so as not to fall by a holding member 3 protruding from the core 1A. During the cooling process of the heated resin molding die 1, the softened molten resin 100A is separated from the cavity 1B and becomes softened molten resin 100A, and a plurality of anchor-shaped recesses 101 that communicate with the underside are formed in the molten resin 100A by a plurality of protruding members 11 on the core 1A.

[0021] Fig. 6 shows the state in which the resin molding die 1 is opened to obtain a resin molded product 100 in the cooling step 93. In Fig. 6, the softened molten resin 100A is cooled and solidified to become the resin molded product 100, the tip of the holding member 3 protruding from the core 1A descends to the upper surface of the core 1A, and the resin molded product 100 is obtained from the resin molding die 1. As shown in Fig. 7, a plurality of recesses 101 are formed inside the resin molded product 100 by the protruding members 11 of the core 1A, and each recess 101 has an anchor shape that communicates with the lower surface of the resin molded product 100.

[0022] (Use of resin molding dies for two-color molding) Referring to Figures 8 and 9, we will explain two-color molding in which a resin molded product 100 obtained in a resin molding mold 1 is used as a primary molded product, and a secondary molding resin is laminated as a resin layer 200 on the primary molded resin molded product 100.

[0023] Figure 8 shows a two-color molding mold 10, which is an injection molding mold having a core 10A and a cavity 10B. The core 10A is a mold that can be moved up and down by a mold opening and closing drive device (not shown), and the cavity 10B is a fixed mold with a nozzle 20 provided above that injects and fills secondary molding resin into a space 10C formed by the core 10A and the cavity 10B. In Figure 8, the resin molded product 100 shown in Figure 7 is turned upside down, and the resin molded product 100 with the anchor-shaped recess 101 connected to the top surface is set on the core 10A so that the top surface of the resin molded product 100 faces the cavity 10B. The two-color molding mold 10 is then closed, and secondary molding resin is injected from the nozzle 20 into the space 10C between the resin molded product 100 and the cavity 10B to fill it. The secondary molding resin then flows into the anchor-shaped recess 101 from the part that is connected to the top surface of the resin molded product 100 and solidifies, and a resin layer 200 is laminated on the resin molded product 100. As shown in Figure 9, a two-color molded product 300 is obtained in which the resin layer 200 is bonded to and laminated on the resin molded product 100. The two-color molded product 300 obtained in this manner has the resin molded product 100 entering the anchor-shaped recess 101 from the portion where the resin layer 200 is connected to the upper surface of the resin molded product 100, and the anchor effect enhances the bond between the resin molded product 100 and the resin layer 200, thereby making it possible to enhance the bond even when two-color molding is performed using a resin material with low bonding properties. In this case, the recess 101 in the resin molded product 100 is formed so as to communicate only with the upper surface of the resin molded product 100, and the resin layer 200 is laminated on the upper surface of the resin molded product 100 as shown in the figure. However, by scanning pulsed laser light L in a direction along the surfaces of the core 10A and cavity 10B, and using a resin molding die 1 in which protruding members 11 with large cross-sectional areas at the tips are formed on the surfaces of the core 1A and cavity 1B (not shown), a resin molded product 100 having recesses 101 formed on both sides can be obtained. This resin molded product 100 is then set in a two-color molding die 10, and secondary molding resin is injected onto both sides of the resin molded product 100 to mold it, resulting in a two-color molded product 300 in which resin layers 200 with improved bonding properties due to the anchor effect are laminated on both sides of the resin molded product 100.In this way, the resin molding mold 1 has a protrusion member 11 with a large cross-sectional area at the tip formed on the surface of at least one of the core 1A and cavity 1B, so that the resin molded product 100 molded with the resin molding mold 1 can be used for two-color molding in which the resin for secondary molding is laminated as the resin layer 200 as the primary molded product, thereby improving the bonding between the resin molded product 100 and the resin layer 200. [Industrial Applicability]

[0024] In the present invention, a resin molded product obtained using a resin molding die can be used in a two-color molding process. [Explanation of symbols]

[0025] 1 Resin molding mold 1A Core 1B cavity 1C space section 11 Protruding member 12 nozzle holes 2 nozzles 3 Retaining member 100 Resin molded products 101 Recess 10 Two-color molding 10A Core 10B cavity 200 Resin layer 200 300 Two-color molded product

Claims

1. A resin joining method using two-color molding, characterized in that a resin molding die is prepared in which a pulsed laser beam is scanned over the surface of at least one of a core and cavity made of a metal material to form a plurality of protruding members with a large cross-sectional area at the tip, the core and cavity of the resin molding die are closed, and a thermoplastic resin is injection molded into the space having the plurality of protruding members to obtain a primary molded product consisting of a resin molded product in which a plurality of anchor-shaped recesses are formed by the plurality of protruding members, and the primary molded product is set in a two-color molding die and secondary molding thermoplastic resin is filled into the plurality of anchor-shaped recesses, thereby forming a resin layer of secondary molding thermoplastic resin on the primary molded product, and a two-color molded product is obtained in which the resin layer of secondary molding thermoplastic resin is bonded to the resin molded product via the anchor-shaped recesses.

2. The resin joining method by two-color molding according to claim 1, characterized in that a pulsed laser beam is scanned on the surface of at least one of the core and cavity of the resin molding die to form a plurality of protrusion members with large cross-sectional areas at the tips on the surface, the pulsed laser beam being laser beam L, and a coefficient R expressed by equation (1) consisting of a scanning frequency h of the laser beam L, a pulse width t of the laser beam L, and a scanning speed v of the laser beam L based on the thermal diffusion coefficient of the metal material of the core or cavity is specified, and the laser beam L having a coefficient R of 0.1 to 1.0 is irradiated while scanning in a direction along the surface of the core or cavity. R=2h√kt / v...Formula (1) (Here, in formula (1), h is the scanning frequency of the laser light, k in √kt is the thermal diffusion coefficient of the metal material that constitutes the cavity and core of the resin molding die, t in √kt is the pulse width of the laser light, and v is the scanning speed of the laser light.)

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