JP4824128B2 - Method for producing multilayer molded article and mold set for multilayer molded article - Google Patents

Description

  The present invention relates to a method for producing a multilayer molded product that is composite-molded with a plurality of resins, and a mold set used in the method.

  There exists following patent document 1 as invention regarding a multilayer molded article. In the invention described in Patent Document 1, a movable mold (cavity mold) is clamped to a first fixed mold (first core mold) in which a transparent surface layer material that has been molded in advance is set in a recess. The first resin is injected from the gate to form a primary molded product on the back surface of the surface layer material. The mold is opened once, and the second fixed mold (second core mold) is movable while holding the primary molded product on the movable mold. Slide the mold to the mold, clamp the second fixed mold and the movable mold, inject the second resin from the second gate, mold the secondary molded product on the back of the primary molded product, and open the mold again Then, a series of steps of taking out the obtained multilayer molded product from the mold is performed.

  According to the above configuration, since the primary molded product and the secondary molded product can be laminated on the back surface of the transparent surface material, the inside of the main body can be colored by coloring either the primary molded product or the secondary molded product. On the other hand, the primary molded product can be made transparent so that the lower secondary molded product can be seen through.

JP 2005-66834 A

By the way, it is possible to provide a preformed intermediate layer in an insert shape between the first resin layer and the second resin layer by devising the shape of the mold and the injection process. For example, if the primary molded product placed on the back side of the intermediate layer is made of a transparent material and appropriate colors and designs are arranged on the intermediate layer, the color and design of the intermediate layer can be visually recognized through the primary molded product. A design with a feeling can be given, and it is excellent in aesthetics. Even if the intermediate layer has no color or design, since the three layers of the primary molded product, the intermediate layer, and the secondary molded product are laminated, the physical strength is increased and the durability is improved.
In the configuration in which the intermediate layer is provided between the primary molded product and the secondary molded product, when the second resin is injected, the heat of the second resin is not directly transmitted to the primary molded product but is transmitted in a state of being buffered by the intermediate layer. Therefore, the effect that the phenomenon that the primary molded product is remelted by the heat received from the second resin and becomes unevenly distributed is suppressed is also exhibited.

However, if an intermediate layer (decorative layer) with a pattern is provided between the primary molded product and the secondary molded product, the phenomenon that the intermediate layer is remelted by heat when the resin for secondary molding is injected may cause a so-called gate jump. was there. Gate jumping means that when a secondary molding resin at a high temperature (250 ° C. to 280 ° C.) comes into contact with the intermediate layer, the heat of this resin is transferred to the intermediate layer, while the heat is due to the heat insulating effect of the primary molded product. Since it is difficult to transfer heat to the mold, it refers to a phenomenon in which the intermediate layer becomes hot and melts and deforms so that the pattern flows.
In addition, the phenomenon that the primary molded product is remelted cannot be sufficiently prevented by simply providing an intermediate layer between the primary molded product and the secondary molded product. To prevent it sufficiently, the primary molded product is thickened. There is also a problem that the thickness of the multilayer molded product cannot be made sufficiently small.

  The present invention has been made in view of the above circumstances, and the object thereof is to inject a resin into a cavity disposed on the other surface of the intermediate layer fused with the first resin layer to thereby provide the second resin layer. The method of manufacturing a multilayer molded product capable of suppressing the phenomenon of intermediate layer gate jumping or more effectively suppressing remelting of the primary molded product, and such a multilayer molding die Is to provide.

The first characteristic configuration of the method for producing a multilayer molded article of the present invention is:
A method for producing a multilayer molded article comprising a first resin layer and a second resin layer arranged with a decorative sheet interposed therebetween,
A first step of providing a primary molded product in which the first resin layer is fused to one side of the decorative sheet ;
A second step of injecting resin into a cavity disposed on the other surface of the decorative sheet to form the second resin layer,
On the outer periphery of the decorative sheet, a protruding piece that protrudes to the outside of the multilayer molded product and contacts the support mold of the primary molded product is formed.
In the second step, the resin is injected into the cavity through a channel facing the protruding piece.

The first characteristic configuration of the multilayer molding die of the present invention is:
A mold set for a multilayer molded article having a first resin layer and a second resin layer arranged with a decorative sheet interposed therebetween,
A first mold capable of supporting a primary molded product in which the first resin layer is fused to one side of the decorative sheet;
A second mold for forming a cavity for receiving resin on the other side of the decorative sheet,
The first mold includes a support portion that supports the protruding pieces formed on the outer peripheral portion of the decorative sheet in contact with each other when the first mold and the second mold are clamped. And
The flow path for injecting resin into the cavity is provided so as to include a portion facing the protruding piece.

According to these characteristic configurations, the injected second resin contacts the decorative sheet through a space sandwiched between the protruding piece and the mold on one side. In this case, even if the heat of the second resin is heated transfer decorative sheet second resin hot contacts the decorative sheet, the heat of the decorative sheet is liable conducts the heat to the type of the other side through the projecting piece , The decorative sheet is difficult to become high temperature. Further, especially when the protruding piece is provided on the decorative sheet, heat transferred from the second resin projecting portions of the decorative sheet, other than the projecting piece on which spread first along the width direction of the protruding piece since transmitted to the body of the decorative sheet, as compared with the case where the heat from the second resin without protruding piece is transmitted directly to the body of the decorative sheet, the local areas of the decorative sheet hardly become hot. For this reason, melting of the decorative sheet and deformation of the design (gate jumping) can be prevented. In particular, the location in the vicinity of the protruding piece in the decorative sheet is likely to become high temperature and the decorative sheet is likely to melt, but the heat in the vicinity of the protruding piece is transferred to the mold on the other side by the protruding piece. Thus, melting of the decorative sheet can be appropriately prevented.

Moreover, according to these characteristic configurations, not only the decorative sheet is provided between the primary molded product and the secondary molded product, but also the heat of the second resin is transferred to the mold on the other side through the protruding piece. Since the amount of heat transferred to the primary molded product is reduced, the phenomenon that the primary molded product is remelted is sufficiently prevented, and as a result, the thickness of the multilayer molded product can be made sufficiently small.

  Another feature of the present invention is that, in the method for producing a multilayer molded product according to the present invention, in the second step, the resin is injected in a state where the edge of the protruding piece is fixed.

  According to this characteristic configuration, it is possible to prevent the decorating layer from being displaced and causing the decorating layer to float or turn up when the second resin is injected. Thereby, since the contact with the protrusion piece and the mold on the other side can be maintained satisfactorily, the heat of the decorative layer can be reliably transferred to the mold on the other side through the protrusion piece. For this reason, melting of the decorative layer can be reliably prevented.

Another feature of the present invention is that in the multilayer molding die according to the present invention, the edge of the protruding piece is sandwiched and fixed to the first die and the second die based on the clamping. The pressing part is provided.

According to this construction, since the fixed by sandwiching the projecting piece in the first mold and the second mold, prevents the slippage between the first mold and the second mold and a projecting piece And it can prevent further that the position of a decoration layer shifts | deviates at the time of 2nd resin injection | pouring, and the float of a decoration layer and a turn are produced. Moreover, when the first mold and the second mold and clamping, since sandwich the projection piece in the first mold and the second mold, unnecessary that provide a separate structure for holding the projecting piece For example, the configuration can be simplified.

Another characteristic configuration of the present invention is that the first mold includes fixing means for fixing an edge of the protruding piece to the first mold .

  Another feature of the present invention is that, in the second step, the location of the flow path facing the protruding piece is linearly connected to the inlet portion of the cavity. The resin is injected along the extending direction of the protruding piece in a state where the facing flow path is connected along the cavity.

According to this characteristic configuration, the injected second resin can flow smoothly along these portions of the decorative sheet without making a frontal collision contact with the protruding piece of the decorative sheet and the main body portion. Will enter. Therefore, in comparison with the configuration in which the resin to be injected enters the contact while the cavity so as to impinging the decorative sheet and the front, the resin is a fear is reduced causing stagnation in the vicinity of the decorative sheet, the resin heat Is more difficult to affect the decorative sheet .

Another feature of the present invention is that the cavity is formed between the decorative sheet supported by the first mold and the decorative film disposed on the inner surface of the second mold, and the decorative film The clamp for fixing the clamp to the second mold is provided at a position in contact with the base end of the protruding piece, and in the second step, the clamp is at a position in contact with the base end of the protruding piece. The resin is injected in the provided state.

  According to this characteristic configuration, the decorative film is pressed against the second mold by the clamp up to the position immediately before the portion of the decorative film incorporated in the main body portion of the final molded product. The phenomenon of floating from the inner surface of the recess of the two molds is also suppressed, and a molded product with good quality can be obtained.

Another feature of the present invention is that, in the second step, the step-shaped recess for receiving the tip of the protruding piece formed in the decorative sheet is provided in the first mold. The point is that the resin is injected in a state where the tip of the protruding piece is retracted into the stepped recess.

According to this characteristic configuration, the tip of the protruding piece of the decorative sheet is protected by the step-shaped recess, so that the decorative sheet can be prevented from being lifted or turned up due to the flow of the resin, and the quality is good. Can be obtained.

FIG. 1 is an overall side sectional view of a multilayer molding die in a first embodiment. FIG. 2 is an overall side sectional view of the multilayer molding die in the first embodiment. FIG. 3 is an overall side sectional view of the multilayer molding die in the first embodiment. FIG. 4 is an overall side cross-sectional view of the multilayer molding die in the first embodiment. FIG. 5 is a cross-sectional view taken along the line II in FIG. 6 is a cross-sectional view taken along the line II in FIG. FIG. 7 is an overall perspective view of the multilayer molded article in the first embodiment. FIG. 8 is an overall cross-sectional side view of the multilayer molding die in the second embodiment. FIG. 9 is an overall sectional side view of the multilayer molding die in the second embodiment. FIG. 10 is an overall cross-sectional side view of the multilayer molding die in the second embodiment. FIG. 11 is an overall side cross-sectional view of the multilayer molding die in the second embodiment. FIG. 12 is a sectional side view when the movable mold and the second fixed mold are clamped in the second embodiment. FIG. 13 is a cross-sectional plan view when the movable mold and the first fixed mold in the third embodiment are clamped. 14 is a cross-sectional view taken along the line II-II in FIG. FIG. 15 is a cross-sectional view taken along the line II in FIG. FIG. 16 is a plan sectional view when the movable mold and the second fixed mold are clamped in the third embodiment. 17 is a cross-sectional view taken along the line IV-IV in FIG. 18 is a cross-sectional view taken along arrow III-III in FIG. FIG. 19 is an overall perspective view of a multilayer molded product according to the third embodiment. FIG. 20 is a side sectional view when the movable mold and the first fixed mold are clamped in another embodiment. FIG. 21 is a sectional side view when the movable mold and the second fixed mold are clamped in another embodiment. FIG. 22 is an overall side cross-sectional view of the multilayer molding die in the fourth embodiment. FIG. 23 is an overall side cross-sectional view of the multilayer molding die in the fourth embodiment. FIG. 24 is an overall side cross-sectional view of a multilayer molding die in the fourth embodiment. FIG. 25 is an overall side cross-sectional view of the multilayer molding die in the fourth embodiment. FIG. 26 is a partially enlarged view of the vicinity of the first gate in FIG. FIG. 27 is a partially enlarged view of the vicinity of the second gate in FIG. FIG. 28 is a perspective view showing the second fixed mold in FIG. FIG. 29 is a schematic view of a secondary molded product obtained by the fourth embodiment.

[First embodiment]
Hereinafter, the multilayer molding die according to the present invention will be described.
A multi-layer molding die according to the present invention is provided in a multi-layer molding machine whose parts are shown in the drawing. As shown in FIGS. 1 to 4, the first movable mold 1A and the second movable mold 1B. (Both are examples of a first mold) and a first fixed mold 3 and a second fixed mold 7 (an example of a second mold).
FIG. 1 shows a state in which the movable molds 1A and 1B are separated from the fixed molds 3 and 7. FIG. As shown in FIG. 2, when the first fixed mold 3 and the first movable mold 1A are clamped, a first cavity 2 that receives the first resin is formed. On the other hand, when the second fixed mold 7 and the second movable mold 1B are clamped, a second cavity 6 for receiving the second resin is formed. FIG. 3 shows a state where the injection of the first resin and the second resin is completed, and FIG. 4 shows a state where the molds are opened by separating the movable molds 1A and 1B again.

  The multilayer molding machine includes a fixed platen 8 and a rotary platen 9 that can rotate with respect to the fixed platen 8 and can be moved back and forth. The fixed plate 8 has a first fixed die 3 and a second fixed die 7, and the rotary plate 9 has a pair of movable dies 1A and 1B. Since each of the pair of movable molds 1A and 1B and each of the first fixed mold 3 and the second fixed mold 7 are arranged so as to face each other, as shown in FIG. When pressed, the pair of movable molds 1A, 1B are simultaneously clamped to the first fixed mold 3 and the second fixed mold 7, and the first resin and the second resin can be injected simultaneously.

  In the state before mold clamping in FIG. 1, the first movable product 1 (the first resin layer 4 and the decorative sheet 5) molded in the previous process is formed on the second movable mold 1 </ b> B facing the second fixed mold 7. The decorative film 12 waiting for the secondary molding is arranged on the second fixed mold 7. Here, the decorative sheet 5 constitutes an intermediate layer. On the other hand, the decorative sheet 5 used in the subsequent primary molding is held on the first fixed mold 3. The multilayer molding machine includes a robot device 15 for installing the decorative sheet 5 on the first fixed mold 3.

  The decorative sheet 5 (which is an intermediate layer and is an example of a decorative layer) is a resin molded body that has been molded in advance according to the shape of the first fixed mold 3, and is inserted between the first resin and the second resin. And is permanently left inside the multilayer molded product. Various patterns can be formed on the decorative sheet 5, but a plain color sheet without a pattern may be used. The decorative sheet 5 can be made of various resins such as an acrylic resin and a polyolefin resin, but if it is made of a heat-resistant resin such as a polycarbonate resin or PET, it is more effective against a phenomenon such as a gate jump. Is. The range of 75-200 μm is appropriate for the thickness of the decorative sheet 5, and 125-150 μm is the easiest to use.

The decorative film 12 (which is a thermal transfer foil and is an example of a decorative layer) includes a decorative portion 12a fused to the first resin layer or the second resin layer and a base sheet 12b for handling. The base sheet 12b is peeled off at an arbitrary step after the decorative portion 12a is fused to the resin layer. The decorative portion 12a generally has a peeling protective layer that is the outermost layer of the final multilayer molded article and an adhesive layer that is fused to the resin layer, and generally a pattern layer between the peeling protective layer and the adhesive layer. However, it is good also as a plain colored film without a pattern.
As the material of the base sheet 12b, a single layer sheet selected from polycarbonate resin, polyamide resin, polyimide resin, polyester resin, acrylic resin, olefin resin, urethane resin, acrylonitrile butadiene styrene resin, etc. Alternatively, a laminated sheet or a copolymer sheet made of two or more kinds of resins selected from the above can be used. Moreover, in order to improve the peelability of the base sheet 12b, a release layer made of an aminoalkyd resin or the like may be formed between the base sheet 12b and the decorative portion. The thickness of the base sheet 12b is preferably 5 to 500 μm.

Materials for the peel protection layer include acrylic resins, nitrified cotton resins, polyurethane resins, chlorinated rubber resins, vinyl chloride-vinyl acetate copolymer resins, polyamide resins, polyester resins, epoxy resins, and polycarbonate resins. Resin, olefin resin, acrylonitrile butadiene styrene resin, or the like may be used. The thickness of the peeling protective layer is preferably 0.5 to 50 μm.
Design layer materials include acrylic resins, nitrified cotton resins, polyurethane resins, chlorinated rubber resins, vinyl chloride-vinyl acetate copolymer resins, polyamide resins, polyester resins, and epoxy resins. It is preferable to use a colored ink containing a suitable color pigment or dye as a colorant.
For the adhesive layer, a material having a high affinity with the resin to be fused should be selected. The thickness of the adhesive layer is preferably 0.5 to 50 μm.

  As shown in FIG. 2, when the first movable mold 1 </ b> A and the first fixed mold 3 are clamped, the decorative sheet 5 in which the first cavity 2 for receiving the first resin is supported by the first fixed mold 3 and the first It is formed between the movable molds 1A. A first gate 10 for injecting the first resin into the first cavity 2 is provided in the first fixed mold 3.

  On the other hand, when the second movable mold 1B and the second fixed mold 7 are clamped, between the decorative film 12 supported by the second fixed mold 7 and the decorative sheet 5 supported by the second movable mold 1B. A second cavity 6 for receiving the second resin is formed. A second gate 11 for injecting the second resin into the second cavity 6 is provided in the second fixed mold 7. The second fixed mold 7 includes a film feeding device 13 for feeding the decorative film 12, a film winding device 14 for winding the decorative film 12, and a rectangle for pressing the decorative film 12 against the second fixed mold 7. A frame-shaped clamp 16 is provided.

The first resin and the second resin may be different color resins, or may be different types of resins having different hardness and other characteristics. For example, the first resin may be polycarbonate resin, ABS resin, or an alloy of polycarbonate resin and ABS resin, and the second resin may be PMMA (polymethyl methacrylate resin). In particular, when the first resin is an ABS resin and the second resin is PMMA, the ABS resin has high moldability, so that multilayer molding such as two-color molding can be performed satisfactorily. Moreover, even if the softening temperature of the ABS resin is lower than the softening temperature of PMMA, the presence of the decorative sheet 5 prevents the molded ABS resin from being deformed by the heat of PMMA when the polymethyl methacrylate resin is injected. Is done.
Moreover, if both the peeling protective layer and the design layer of the decorative film 12 and the second resin are PMMA, the surfaces of both members are melted and integrated by the heat of the PMMA, so an adhesive layer is provided on the decorative film 12. There is no need to provide it.

  The movable mold 1 is provided with a slide piece 17 (an example of a fixing means) that fixes a part of the decorative sheet 5 and a generally rectangular groove 18 that accommodates the clamp 16 during mold clamping. Details of these configurations are shown in FIG. 5 (II cross section in FIG. 3) and FIG. 6 (II cross section in FIG. 5), and the whole decorative sheet 5 is shown in FIG. As shown in FIG. 7 showing the secondary molded product F2 removed from the movable mold 1 after solidification, an edge 5b of a trapezoidal protruding piece 5a is formed on one side of the decorative sheet 5, and this edge 5b is fixed by the slide piece 17 described above. The second movable mold 1B is formed with an auxiliary cavity 19 that can accommodate the protruding piece 5a when the second fixed mold 7 and the movable mold 1 are clamped. The second gate 11 for injecting the second resin is provided at a position where the second resin is always injected into the second cavity 6 through the auxiliary cavity 19.

  More specifically, when the second movable mold 1B and the second fixed mold 7 are clamped, a communication flow path 20 that connects the second gate 11 and the second cavity 6 to each other is formed therebetween. The second resin injected from the second gate 11 is injected into the second cavity 6 through the communication channel 20. The communication flow path 20 includes a linear first flow path portion 21 that extends from the second gate 11 to the clamp 16 on the near side, and a substantially U-shaped second flow path portion 22 that detours around the clamp 16. , And an auxiliary cavity 19 that leaves the second flow path portion 22 and goes to the far clamp 16. As shown in FIG. 5, the auxiliary cavity 19 that can accommodate the protruding piece 5a has a divergent shape that becomes wider as it approaches the primary molded product F1.

  As a result of the configuration of the communication channel 20, when the second resin is injected, the second resin always starts to contact the decorative sheet 5 through the space surrounded by the protruding piece 5 a and the second fixed mold 7. To do. Therefore, even if the high-temperature second resin comes into contact with the decorative sheet 5 and the heat of the second resin transfers to the decorative sheet 5, the heat received by the decorative sheet 5 passes through the projecting pieces 5a having a large area. Since the heat is effectively dissipated to the movable mold 1, the decorative sheet 5 does not become too high, and the decorative sheet 5 is prevented from melting. In addition, when the mold is clamped, the clamp 16 slides the slide piece 17 so as to push it up toward the protruding piece 5a, so that the edge 5b of the protruding piece 5a is sandwiched and fixed between the slide piece 17 and the second movable mold 1B. Therefore, the phenomenon that the position of the decorating sheet 5 shifts when the second resin is injected can also be prevented. Thereby, since the contact of the protruding piece 5a and the second movable mold 1B is also maintained well, the heat of the decorative sheet 5 is reliably transferred to the second movable mold 1B through the protruding piece 5a and the protruding piece 5a. The heat of the edge portion 5b can be efficiently and efficiently radiated to the second movable mold 1B and the slide piece 17. For this reason, melting of the decorative sheet 5 can be reliably prevented. Moreover, the decorative sheet 5 can be prevented from being lifted, “turned over”, and the like, and a multilayer molded product can be manufactured satisfactorily.

Here, a specific method for producing a multilayer molded article (two-color molded article) using the multilayer molding die according to the present invention will be described.
In the present embodiment, the molded decorative sheet 5 is placed on the first fixed mold 3 by the robot device 15. On the other hand, in the second fixed mold 7, the decorative film 12 having a certain length is fed by the film feeding device 13, and at the same time, the decorative film 12 having the certain length is wound by the film winding device 14. The film 12 is opposed to the second fixed mold 7 (see FIG. 1). The decorative film 12 is pressed against the edge of the second fixed mold 7 by the clamp 16, the decorative film 12 is heated by a heating device (not shown), and the decorative film 12 is pressed by a suction device (not shown). The second fixed mold 7 is brought into close contact with the concave portion. At this time, the movable mold 1 facing the second fixed mold 7 holds the primary molded product F1 including the first resin layer 4 and the decorative sheet 5 fused to the upper surface of the first resin layer 4. ing.

  Next, as shown in FIG. 2, the rotary plate 9 is moved toward the fixed platen 8 to clamp the first movable die 1A and the first fixed die 3, and the second movable die 1B and the second The fixed mold 7 is clamped. As a result, the first cavity 2 is formed between the decorative sheet 5 supported by the first fixed mold 3 and the first movable mold 1A. At the same time, the second cavity 6 is formed between the decorative film 12 supported by the second fixed mold 7 and the primary molded product F1 supported by the second movable mold 1B. At the same time, the slide piece 17 pressed by the clamp 16 during mold clamping slides toward the protruding piece 5a, so that the slide piece 17 (an example of a pressing portion) and a part of the other movable die 1 (an example of a pressing portion) ) Sandwiches and fixes the edge 5b of the protruding piece 5a. As shown in FIG. 3, the 1st resin inject | emitted from the 1st gate 10 is inject | poured into the 1st cavity 2, the 1st resin layer 4 is shape | molded on the lower surface of the decorating sheet 5, and becomes the next primary molded product F1. . On the other hand, as shown in FIGS. 3 and 6, the second resin injected from the second gate 11 is injected into the second cavity 6, and the decorative film 12, the primary molded product F1, and the second resin layer 23 are integrated. The secondary molded product F2 is molded.

  Thereafter, as shown in FIG. 4, the rotary plate 9 is separated from the fixed plate 8, and both movable molds 1 are opened from the first fixed mold 3 and the second fixed mold 7. By this mold opening, the base sheet 12a of the decorative film 12 is naturally peeled from the decorative portion 12b, and a secondary molded product F2 in which only the decorative portion 12b is transferred to the surface of the second resin is obtained. Therefore, the solidified secondary molded product F1 is removed from the movable mold 1, and the turntable 9 is rotated 180 degrees. And by repeating the said operation, the secondary molded product F2 by which the primary resin layer 4, the decorating sheet 5, the secondary resin layer 23, and the decorating part 12b of the decorating film 12 were laminated | stacked one by one is manufactured. The decorative portion 12b transferred to the secondary molded product F2 includes an adhesive layer fused to the second resin layer 23, an intermediate design layer, and an outermost peeling protective layer. In addition, as a finishing process, the protrusion piece 5a which protrudes outside the secondary molded product F2 is cut with an instrument such as a scissors (see FIG. 7).

[Second Embodiment]
In the second embodiment shown in FIGS. 8 to 12 below, only the configuration different from the configuration of the first embodiment will be mainly described, and the description of the same configuration will be omitted.
As shown in FIG. 8, the multilayer mold used in the second embodiment includes a first fixed mold 33, a second fixed mold 37 (an example of a second mold), and a pair of movable molds 31 (first mold). In contrast to the first embodiment, the fixed molds 33 and 37 are convex male types, and the pair of movable molds 31 are concave female types.
As shown in FIG. 9, when the first fixed mold 33 and the first movable mold 31A are clamped, a first cavity 32 for receiving the first resin is formed, and the second fixed mold 37 and the second movable mold 31B are formed into a mold. When tightened, a second cavity 36 for receiving the second resin is formed.

  The auxiliary cavity 38 formed in the movable mold 31 can accommodate the protruding piece 35a of the decorative sheet 35 when the second movable mold 31B and the second fixed mold 37 are clamped. The second gate 39 for injecting the second resin is provided at a position where the second resin is always injected into the second cavity 36 through the auxiliary cavity 38.

  More specifically, as shown in FIG. 12, when the second movable mold 31B and the second fixed mold 37 are clamped, the second gate 39 and the second movable mold 31B are interposed between the second movable mold 31B and the second fixed mold 37. A communication channel 40 that communicates with the second cavity 36 is formed. The second resin injected from the second gate 39 is injected into the second cavity 36 through the communication channel 40. The communication flow path 40 includes a linear first flow path portion 41 that extends from the second gate 39 to the clamp 16 on the near side, and a substantially U-shaped second flow path portion 42 that detours around the clamp 16. , And an auxiliary cavity 38 extending from the second flow path portion 42 toward the remote clamp 16. Similar to the auxiliary cavity 19 of the first embodiment, the auxiliary cavity 38 that can accommodate the protruding pieces 35a has a divergent shape that becomes wider from the second flow path portion 42 toward the primary molded product F1.

  As a result of the configuration of the communication flow path 40, when the second resin is injected, the second resin always comes into contact with the decorative sheet 35 through the space surrounded by the protruding piece 35a and the second fixed mold 37. . Therefore, even if the high-temperature second resin comes into contact with the decorative sheet 35 and the heat of the second resin is transferred to the decorative sheet 35, the heat received by the decorative sheet 35 is via the protruding piece 35a having a large area. Since the heat is effectively dissipated to the movable mold 31, the decorative sheet 35 does not reach a very high temperature, and melting of the decorative sheet 35 and deformation of the design are prevented. Moreover, since the edge portion 35b of the protruding piece 35a is sandwiched and fixed between the slide piece 17 and the second movable die 31B during mold clamping, it is possible to prevent the phenomenon that the position of the decorative sheet 35 is shifted when the second resin is injected. . Thereby, since the contact between the protruding piece 35a and the second movable mold 31B is also maintained well, the heat of the decorative sheet 35 is reliably transferred to the second movable mold 31B through the protruding piece 53a, and the protruding piece 35a. The heat of the edge portion 35b can be efficiently and efficiently radiated to the movable mold 31 and the slide piece 17. For this reason, melting of the decorative sheet 35 can be reliably prevented. In addition, the multi-layer molded product can be manufactured satisfactorily by preventing the decorating sheet 35 from floating and turning.

Next, a specific method for manufacturing a multilayer molded article in the second embodiment will be described.
In the present embodiment, as shown in FIG. 8, in the first movable mold 31 </ b> A, the decorative film 12 having a certain length is fed by the film feeding device 13, and at the same time, the fixed film having a certain length is added by the film winding device 14. By winding up the decorative film 12, the decorative film 12 is opposed to the first movable mold 31A, pressed against the edge of the mold 31A by the clamp 16, heated by the heating device, and heated by the suction device. The decorative film 12 is brought into close contact with the concave portion of the first movable mold 31A. At this time, the decoration sheet 35 is held by the robot device 15 in the first fixed mold 33 facing the first movable mold 31A. The other movable mold 31 holds the primary molded product F1 (the first resin layer 34 and the decorative sheet 35) molded in the previous step.

  Next, as shown in FIG. 9, the rotary plate 9 is moved to the fixed platen 8 side to clamp the first movable die 31 </ b> A and the first fixed die 33, and the second movable die 31 </ b> B and the second movable die 31 </ b> B. The fixed mold 37 is clamped. As a result, the first cavity 32 is formed between the decorative film 12 supported by the first movable mold 31 </ b> A and the decorative sheet 35 supported by the first fixed mold 33. At the same time, the second cavity 36 is formed between the primary molded product F1 supported by the second movable mold 31B and the second fixed mold 37. The slide piece 17 pressed by the clamp 16 during the mold clamping slides toward the protruding piece 35a, so that the slide piece 17 (an example of a pressing portion) and a part of the other movable die 31 (an example of a pressing portion). Sandwiches and fixes the edge 35b of the protruding piece 35a. As shown in FIG. 10, the first resin injected from the first gate 49 is injected into the first cavity 32, and a primary resin layer 34 is formed between the decorative film 12 and the decorative sheet 35, and primary molding is performed. Product F1 is obtained. On the other hand, as shown in FIGS. 10 and 12, the second resin injected from the second gate 39 is injected into the second cavity 36, and the molded product in which the primary molded product F1 and the second resin layer 43 are integrated. Is obtained.

  After that, as shown in FIG. 11, the rotating plate 9 is separated from the fixed plate 8, and both movable molds 31 are opened from the first fixed mold 33 and the second fixed mold 37. By this mold opening, the base sheet 12a of the decorative film 12 of the secondary molded product F2 supported by the second fixed mold 37 is naturally peeled off, and only the decorative portion 12b is transferred to the surface of the primary resin layer 34. A secondary molded product F2 is obtained. Therefore, the solidified secondary molded product F2 is removed from the movable mold 1, and the turntable 9 is rotated 180 degrees. And by repeating the said operation, the secondary molded product F2 by which the secondary resin layer 34, the decorating sheet 35, the primary resin layer 34, and the decorating part 12b of the decorating film 12 were laminated | stacked one by one is manufactured.

[Third embodiment]
As shown in FIGS. 13 to 18, the multilayer mold used in the third embodiment includes a pair of movable molds 51 </ b> A and 51 </ b> B (an example of a first mold), and a first fixed mold 52 and a second fixed mold. A mold 53 (an example of a second mold) is provided. 13 to 18 show a state after injecting the first resin and the second resin. The third embodiment shows an example in which only the decorative sheet 56 is used and the decorative film 12 is not used. Although not shown, the pair of movable molds 51 </ b> A and 51 </ b> B are supported by the rotating disk 9, and the first fixed mold 52 and the second fixed mold 53 are supported by the fixed disk 8, as in the above embodiment.

When the first fixed mold 52 holding the decorative sheet 56 and the first movable mold 51A are clamped, a first cavity 54 is formed between the decorative sheet 56 and the first movable mold 51A. 14 and 15 show a state where the first resin (55) is injected into the first cavity 54 and the primary molded product F1 is obtained.
On the other hand, when the second movable mold 51B holding the primary molded product F1 injected / molded in the previous process is clamped with respect to the second fixed mold 53, the decorative sheet 56 and the second fixed mold of the primary molded product F1 are clamped. A second cavity 64 is formed between 53. 17 and 18 show a state where the second resin (65) is injected into the second cavity 64 and the secondary molded product F2 is obtained.
As shown in FIG. 18, an auxiliary cavity 71 capable of accommodating the protruding piece 56a of the decorative sheet 56 is formed between the movable mold 51 and the second fixed mold 53, and the second gate 66 for injecting the second resin. Is provided at a position where the second resin is always injected into the second cavity 64 via the auxiliary cavity 71.

  As shown in FIG. 13, the protruding piece 56 a of the decorative sheet 56 has a rectangular shape protruding from substantially the entire width of the long side on one side of the decorative sheet 56. As shown in FIG. 14, which is a II-II cross section in FIG. 13, the cross section along one long side of the convex portion 51 is between the parting surface 51 a and the convex portion 51 b of the first movable mold 51 </ b> A. A V-shaped groove 63 is formed. On the other hand, between the parting surface 52a of the first fixed mold 52 and the recess 52b, a protrusion 62 having a V-shaped cross section that enters the groove 63 is formed. Therefore, when the first movable mold 51A and the first fixed mold 52 are clamped, one side surface 62a of the ridge 62 and one side surface 63a of the groove 63 come into contact with each other, and at the same time, the other side surface 62b (pressing) of the ridge 62 is pressed. The protruding piece 56a of the decorative sheet 56 is sandwiched between the example of the portion and the other side surface 63b of the groove 63 (an example of the pressing portion).

  As shown in FIG. 15, which is a cross section taken along line II in FIG. 13, FIG. 14, and FIG. 13, when the first movable mold 51A and the first fixed mold 52 are clamped, the first movable mold 51A and the first fixed mold are fixed. A first communication channel 61 that connects the first gate 57 and the first cavity 54 is formed between the mold 52. The first resin injected from the first gate 57 is injected into the first cavity 54 through the first communication channel 61. The first communication channel 61 includes a linear first channel portion 58 formed between the parting surface 51a of the first movable mold 51A and the parting surface 52a of the first fixed mold 52, and a ridge 62. Formed between the one side surface 62 a of the groove 63 and the one side surface 63 a of the groove 63, and between the other side surface 62 b of the protrusion 62 and the other side surface 63 b of the groove 63. The third flow path portion 60 is provided. The third flow path portion 60 has a divergent shape that becomes wider from the second flow path portion 59 toward the primary molded product F1. The second flow path portion 59 is connected to the first flow path portion 58 and the third flow path portion 60 is connected to the second flow path portion 59 in a bent shape.

  On the other hand, as shown in FIG. 17 which is a IV-IV cross section in FIG. 16, a V-shaped protrusion 72 entering the groove 63 is formed between the parting surface 53a of the second fixed mold 53 and the recess 53b. Is formed. When the second movable die 51B and the second fixed die 53 are clamped, one side surface 72a of the ridge 72 and one side surface 63a of the groove 63 come into contact with each other, and at the same time, the other side surface 72b of the ridge 72 (the pressing portion of the pressing portion). The protruding piece 56a of the decorative sheet 56 is sandwiched between the example) and the other side surface 63b of the groove 63 (an example of a pressing portion).

  As shown in FIGS. 16, 17, and 18, which is a III-III cross section in FIG. 16, when the second movable mold 51 </ b> B and the second fixed mold 53 are clamped, the second movable mold 51 </ b> B and the second movable mold 51 </ b> A second communication channel 70 is formed between the fixed mold 53 and the second gate 66 and the second cavity 64 to communicate with each other. The second resin injected from the second gate 66 is injected into the second cavity 64 through the second communication channel 70. The second communication channel 70 includes a linear first channel portion 67 formed between the parting surface 51a of the second movable mold 51B and the parting surface 53a of the second fixed mold 53, and a ridge 72. Between the one side surface 72 a of the groove 63 and the one side surface 63 a of the groove 63, and between the other side surface 72 b of the protrusion 72 and the other side surface 63 b of the groove 63. The third flow path portion 69 is provided. The third flow path portion 69 has a divergent shape that becomes wider from the second flow path portion 68 toward the primary molded product F1. The second flow path portion 68 is connected to the first flow path portion 67 and the third flow path portion 69 is connected to the second flow path portion 68 in a bent shape. Between the other side surface 72 b of the protrusion 72 and the other side surface 63 b of the groove 63, an auxiliary cavity 71 that can accommodate a part of the protruding piece 56 a of the decorative sheet 56 is formed. Here, the third flow path portion 69 in which a part of the protruding piece 56 a formed on the decorative sheet 56 is exposed constitutes the auxiliary cavity 71.

As a result of the configuration of the communication flow path 40, when the second resin is injected, the second resin is always decorated through the space surrounded by the protruding piece 56a near the auxiliary cavity 71 and the second fixed mold 53. Contact the sheet 56. Therefore, even if the high-temperature second resin comes into contact with the decorative sheet 56 and the heat of the second resin is transferred to the decorative sheet 56, the heat received by the decorative sheet 56 passes through the protruding pieces 56a having a large area. Since the heat is effectively dissipated to the movable mold 51, the decorative sheet 56 does not become too hot, and the decorative sheet 56 is prevented from melting.
Moreover, during mold clamping, as shown in FIGS. 13 and 14, both side portions 56 c and 56 d that do not overlap the third flow path portion 60 in the protruding piece 56 a are formed by the first movable mold 51 </ b> A and the first fixed mold 52. It is pinched and fixed between. Therefore, when the first resin is injected from the first gate 57 into the first cavity 54 and the primary molded product 55 is molded on the lower surface of the decorative sheet 56, the first resin is between the side surface 62b on the other side. There is no risk of getting into the gap.

  As for the second fixed mold 53 and the second movable mold 51B, as shown in FIGS. 16 and 17, both side portions 56f and 56g that do not overlap the third flow path portion 69 of the protruding piece 56a are movable type. It is clamped and fixed between 51 and the second fixed mold 53. Therefore, when the second resin injected from the second gate 66 is injected into the second cavity 64 and the secondary molded product F2 is formed on the upper surface of the decorative sheet 56, the second resin becomes the other side surface 63b. There is no risk of getting into the gap.

  Thereafter, the second movable mold 51B and the second fixed mold 53 are opened, and the secondary molded product F2 is removed from the second movable mold 51B. For finishing, the protruding pieces 56a protruding from the secondary molded product F2 removed from the movable mold 51, and the protruding portions of the first molded product 55 and the second molded product 65 are cut (see FIG. 19). At this time, since the protruding portions of the protruding piece 56a, the first molded product 55, and the second molded product 65 protrude from the long side on one side of the secondary molded product F2, the process can be performed only once. Reduction and improvement of productivity are achieved. Further, since the projecting piece 56a is sandwiched between the first movable mold 51A and the first fixed mold 52, and the second movable mold 51B and the second fixed mold 53, there is no need to separately provide a configuration for sandwiching the projecting piece 56a. Thus, the configuration can be simplified. Further, it is possible to provide a plurality of gates and perform a plurality of taking.

[Fourth embodiment]
In the fourth embodiment shown in FIGS. 22 to 29 below, only the configuration different from the configuration of the first embodiment will be mainly described, and the description of the same configuration will be omitted.
FIG. 29 (a) schematically shows the appearance of a finished product obtained by removing unnecessary portions from the secondary molded product F2 produced by the multilayer molding die. As can be seen from FIG. 29 (b) showing the BB cross section of FIG. 29 (a), the secondary molded product F2 produced by the multilayer molding die is the innermost first resin layer 44, first It has the decorating sheet 45 (an example of an intermediate | middle layer) located in the outer side of the resin layer 44, the 2nd resin layer 23 of the outer side, and the decorating film 12 located in the outermost side.
The first resin layer 44 is opaque, and a rectangular window is formed near the center thereof. Although the window is not formed in the decorating sheet 45, the 2nd resin layer 23, and the decorating film 12, it is comprised with transparent resin. Therefore, when the secondary molded product F2 is applied to, for example, a display panel of a mobile phone, a liquid crystal screen (not shown) or the like can be seen through the rectangular window of the first resin layer 44.

As shown in FIG. 22, the multilayer mold used in the fourth embodiment includes a first fixed mold 182 and a second fixed mold 183 (both are examples of the second mold) supported by the fixed platen 8, and A pair of movable molds 181A and 181B (an example of a first mold) supported by the rotating disk 9 are provided. The turntable 9 is configured to be rotatable with respect to the fixed platen 8 and to be able to leave and exit. Here, the fixed molds 182 and 183 are concave female types, and the pair of movable molds 181A and 181B are convex male types.
In FIG. 22, the decorative sheet 45 previously produced by electroforming is locked in the concave portion of the first fixed mold 182, and the decorative film 12 is arranged in the concave portion of the second fixed mold 183. The clamp 16 can be fixed.

On the other hand, the primary molded product F1 obtained in the previous step is locked to the convex portion of the second movable mold 181B. The primary molded product F1 has the same shape as the primary molded product F1 shown in FIG.
In FIG. 22, only two places of the clamp 16, the place where the decorative film 12 is fixed above the recess of the second fixed mold 183 and the place where the decorative film 12 is fixed below the recess, are illustrated. However, in actuality, as illustrated in FIG. 28, the clamp 16 has a generally rectangular frame shape, and thus the decorative film 12 is disposed on the entire circumference of the rectangular edge surrounding the concave portion of the second fixed mold 183. Can be fixed. The configuration related to the clamp 16 is common to all the embodiments described in this specification.

Next, as shown in FIG. 23, when the turntable 9 is pressed toward the fixed platen 8, the first fixed die 182 and the first movable die 181A are clamped, and at the same time, the second fixed die 183 and the first fixed die 183 are fixed. The two movable molds 181B are clamped.
In the clamping of the first fixed mold 182 and the first movable mold 181A, as shown in the upper part of FIG. 23, between the decorative sheet 45 locked to the first fixed mold 182 and the first movable mold 181A. A first cavity 132 for receiving the first resin is formed. When the first resin is injected into the first cavity 132, the first resin is fused to the inner surface of the decorative sheet 45, and a primary molded product F1 including the decorative sheet 45 and the first resin layer 44 is obtained (first). An example of one step). FIG. 23 shows a state where the first resin layer 44 has already been injected.

  On the other hand, as shown in the lower part of FIG. 23, in the clamping of the second fixed mold 183 and the second movable mold 181B, the primary molded product F1 locked to the second movable mold 181B and the second fixed mold 183 are A second cavity 136 is formed between the locked decorative film 12 and the second resin is injected into the second cavity 136 (an example of the second step; in the figure, the injected second resin layer 23 is shown). It is shown). Actually, the decorative film 12 is adsorbed to the inner surface of the concave portion of the second fixed mold 183 before the second resin is injected. In order to realize this adsorption, the concave portion of the second fixed mold 183 has a large number of fine suction holes (not shown) and reduced pressure for generating a negative pressure on the inner surface of the concave portion of the second fixed mold 183 through the suction holes. A pump (not shown) is provided. Such an adsorption mechanism is also provided between the first fixed mold 182 and the primary molded product F1.

  As shown in FIGS. 26 to 27 which are enlarged views of the main part of FIG. 23, the decorative sheet 45 is formed with two protruding pieces. One of them is a first projecting piece 45a linearly extending from a part of the edge of the four sides of the decorative sheet 45, and the other is a second projecting bent outward from a part of the opposite side. It is a piece 45b. During the molding steps shown in FIGS. 22 and 23, both the first protruding piece 45a and the second protruding piece 45b are pressed against the inner surface of the first fixed mold 182. As shown in FIG. 29, the projecting pieces 45a and 45b are cut off in the final secondary molded product F2.

As shown in FIG. 27, the first protruding piece 45a is accommodated in the first auxiliary cavity 136a formed in the second movable mold 181B when the second fixed mold 183 and the second movable mold 181B are clamped. Is done.
Further, the second gate 139 for injecting the second resin is at a position where the second resin is always injected into the second cavity 136 through the region of the first auxiliary cavity 136a where the first protruding piece 45a is provided. It is provided.
As shown in FIG. 26, the second projecting piece 45b is one of the second auxiliary cavities 132a formed in the first movable mold 181A when the first fixed mold 182 and the first movable mold 181A are clamped. Housed in the department.

When the solidification of the first resin and the second resin injected in the step shown in FIG. 23 is completed, the pair of movable molds 181A and 181B are respectively separated by pulling the rotating plate 9 away from the fixed plate 8 as shown in FIG. The mold is opened from the first fixed mold 182 and the second fixed mold 183.
In this state, the molded primary molded product F1 is supported on the convex portion of the first movable mold 181A, and the molded secondary molded product F2 is supported on the convex portion of the second movable die 181B.
The secondary molded product F2 is taken out from the second fixed mold 183, and as shown in FIG. 25, the turntable 9 is rotated by 180 °, whereby the steps from FIG. 22 can be repeated.
When processing such as the cutting operation of the protruding pieces 45a and 45b is performed on the secondary molded product F2 taken out in FIG. 24, a secondary molded product F2 (finished product) having an appearance shown in FIG. 29 is obtained.

Here, the steps of FIGS. 22 and 23 will be described again in detail.
First, as shown in FIGS. 23 and 26, by clamping the first fixed mold 182 and the first movable mold 181A, the first gate 138 and the first cavity 132 are connected to each other between the molds 182 and 181A. A communication flow path 140 for communication is formed. The communication flow path 140 includes a straight first flow path portion 140A that directly communicates with the outlet of the first gate 138, and a straight second flow path portion 140B that directly communicates with the first cavity 132. The second flow path portion 140B and the first flow path portion 140A extend substantially parallel to each other, but are connected to each other in a crank shape. On the inner surface of the first fixed mold 182 corresponding to the boundary of the connection, a retracting portion 182X is formed, which is retracted stepwise toward the fixed platen 8 along the first resin entry direction. And the front-end | tip of the 2nd protrusion piece 45b of the decorating sheet 45 is opposingly arranged so that it may be pressed against this retraction part 182X, The float of the decorating sheet 45 by the flow of 1st resin, "turn over", etc. Is prevented. The retraction part 182X has a depth that exceeds the thickness of the decorative sheet 45.

  Next, as shown in FIGS. 23 and 27, by clamping the second fixed mold 183 and the second movable mold 181B, the second gate 139 and the second cavity 136 are placed between the molds 183 and 181B. A communication channel 142 communicating with each other is formed. The communication channel 142 is formed by the second auxiliary cavity 136a, and is formed on the linear first channel portion 142A extending from the second gate 139 to the clamp 16 on the near side, and on the side surface 16b below the clamp 16. Along the second flow path portion 142B that enters so as to approach the turntable 9, along the upper surface 16c of the clamp 16 and the third flow path portion 142C that extends upward in the drawing, and along the upper side surface 16d of the clamp 16. And a fourth flow path portion 142D approaching the second fixed mold 183.

Since the fourth flow path portion 142D, which is the final portion of the communication flow path 142, extends substantially horizontally in the drawing toward the second fixed mold 183, the boundary surface between the second fixed mold 183 and the second movable mold 181B. , The end portion of the fourth channel portion 142D (an example of the location of the channel facing the protruding piece) and the inlet portion of the second cavity 136 are connected substantially linearly without forming an angle with each other. Specifically, the base end portion of the upper side surface 16d in the drawing of the clamp 16 shown in FIG. 27 coincides with the position of the end surface of the final secondary molded product F2 at the point S attached to the drawing. Yes.
In the fourth flow path portion 142D, a retracting portion 142X (an example of a step-shaped concave portion) that is retracted in a staircase pattern near the center line of the second movable mold 181B is formed along the entering direction of the second resin. And the front-end | tip of the 1st protrusion piece 45a of the decorating sheet 45 is opposingly arranged so that it may be pressed by this retraction part 142X, and the float of the decorating sheet 45 by the flow of 2nd resin, "turn over", etc. Is prevented. The retraction part 142 </ b> X has a depth that exceeds the thickness of the decorative sheet 45.

  As a result of configuring the communication flow path 142 in this way, when the second resin is injected, the second resin always passes through the space sandwiched between the first projecting piece 45a and the clamp 16 and is in the second cavity 136. Contact the decorative sheet 45. Therefore, even if the high-temperature second resin comes into contact with the decorative sheet 45 and the heat of the second resin is transferred to the decorative sheet 45, the heat received by the decorative sheet 45 is along the entering direction of the second resin. In order to effectively dissipate heat to the second movable mold 181B through the projecting piece 45a having a divergent shape spreading laterally, the decorative sheet 45 in the second cavity 136 does not reach a very high temperature, and is finally Melting of the main body portion of the decorative sheet 45 incorporated in the secondary molded product F2, deformation of the design, and the like are prevented. Moreover, since the 1st protrusion piece 45a is made into the divergent shape, the heat | fever transmitted from the 2nd resin to the 1st protrusion piece 45a of the decorating sheet 45 spread first along the width direction of the 1st protrusion piece 45a. The phenomenon that the local part of the decorative sheet 45 becomes hot is prevented from being transmitted to the main body of the decorative sheet 45 other than the first protruding piece 45a.

  Further, as described above, since the end portion of the fourth flow path portion 142D and the inlet of the second cavity 136 are connected in a substantially straight line without forming an angle with each other, the second gate 139 is separated from the second gate 139 in the second step. The second resin to be injected is injected along the extending direction of the first protruding piece 45a in a state where the fourth flow path portion 142D facing the first protruding piece 45a is connected along the cavity 135. That is, at this time, the second resin does not make a frontal collision contact with the first projecting piece 45a of the decorative sheet 45 and the main body part incorporated in the final secondary molded product F2, and thus the decorative sheet 45. It enters the second cavity 136 while smoothly flowing along the same body part. Therefore, compared with the structure which the 2nd resin inject | poured from the 2nd gate 139 enters into the 2nd cavity 136, making the contact which collides front with the decorating sheet 45, 2nd resin is the decorating sheet 45's. Since there is less possibility of causing stagnation in the vicinity, the influence of the heat of the second resin is even more difficult for the decorative sheet 45.

  Further, as described above, the base end portion of the upper side surface 16d in the drawing of the clamp 16 shown in FIG. 27 coincides with the position of the end surface of the final secondary molded product F2. That is, the decorative film 12 is pressed against the second fixed mold 183 by the clamp 16 up to the position immediately before the part of the decorative film 12 incorporated in the main body portion of the final secondary molded product F2, so that the decorative film The phenomenon that 12 rises from the inner surface of the concave portion of the second fixed mold 183 is also suppressed.

[Another embodiment]
(1) In each said embodiment, with respect to metal mold | die 1,31,51 holding the primary resin layers 4,34,55 and the decorating sheets 5,35,56, the decorating sheets 5,35,56 The projecting pieces 5a, 35a, 56a previously formed are brought into contact with each other, and a space sandwiched between the projecting pieces 5a, 35a, 56a and the other molds 7, 37, 53 combined with the molds 1, 31, 51 is formed. A configuration in which the second resin is injected via the above is illustrated. However, instead of these configurations, protruding pieces that protrude to the outside of the secondary molded product F2 are formed on the first resin layers 4, 34, and 55, and added to the first resin layers 4, 34, and 55. Another projecting piece is combined with the projecting piece and the molds 1, 31, 51 by bringing the projecting pieces of the first resin layers 4, 34, 55 into contact with the molds 1, 31, 51 holding the decorative sheets 5, 35, 56 It is good also as a structure which inject | pours 2nd resin through the space pinched | interposed with the metal mold | die 7,37,53.

(2) In each of the above embodiments, the decorative sheets 5, 35, 56 are provided on one side of the first resin layers 4, 34, 55 formed by injecting the first resin, and the decorative sheets 5, 35, A configuration in which the second resin is injected into the surface opposite to the 56th first resin layers 4, 34, 55 to manufacture the secondary molded product F2 is exemplified. However, the present invention is not limited to this configuration. For example, the second resin is injected on one side of the primary molded product molded by the first resin injection to form the secondary molded product, and then added to one side of the secondary molded product. A three-layer molded product may be manufactured by providing a decorative sheet and injecting the third resin on the surface of the decorative sheet opposite to the secondary molded product. In short, the present invention can be applied to a method for producing a multilayer molded article by injecting multilayer resin.

(3) In each said embodiment, although the decoration layer illustrated the structure which is the decoration sheets 5, 35, 56, it replaces with such a structure and sets it as the structure whose decoration layer is a decoration film, You may form the protrusion piece which protrudes outside the multilayer molded article in this decorative film.

(4) In each of the above embodiments, the configuration in which the decorative film 12 (thermal transfer foil) is provided on the outer surface of the secondary molded product F1 is exemplified. However, instead of such a configuration, the outside of the secondary molded product F1 A decorative sheet may also be provided on the surface.

(5) In each said embodiment, although the structure which provides the 1st resin layer 4,34,55 in the surface of the other side in the decorating sheets 5,35,56 was illustrated, the 1st resin layer 4,34,55 was illustrated. In addition, for example, a fitting portion that fits into a casing of a mobile phone may be integrally formed. Further, a decorative film or a decorative sheet may be provided on the other surface of the first resin layers 4, 34, 55.

(6) In 1st and 2nd embodiment, although the fixing means illustrated the structure which is the slide piece 17 which clamps the edge 5b of the decorating sheet 5, it is not restricted to such a structure, For example, The fixing unit may be a suction unit that sucks the edge portion 5b.

(7) In the first embodiment, there is a pair of movable molds 1, a turntable 9 that can move in and out in the lateral direction and that can rotate around the axis along the lateral direction, the first fixed mold 3, and the first A multi-layer molding machine provided with a stationary platen 8 having two fixed molds 7 is exemplified. However, the present invention is not limited to such a multi-layer molding machine. For example, it has a movable mold, a first movable plate that can be moved up and down, a first fixed mold, and a second fixed mold. Multi-layer molding machine having a second movable plate slidable in the direction, or a movable plate having a movable mold and movable in and out in the horizontal direction, and the first fixed mold and the second fixed mold are back to back You may implement with the form using the multilayer molding machine provided with the turntable attached and rotated to the surroundings of the shaft center along an up-down direction.

(8) As a modification of the third embodiment, for example, as shown in FIGS. 20 and 21, an inclined portion on the movable mold 51 side is provided between the parting surface 51 a and the convex portion 51 b of the movable mold 51. 73 is formed, and an inclined portion 74 on the side of the first fixed mold 52 facing the inclined portion 73 is formed between the parting surface 52a of the first fixed mold 52 and the recess 52b, and the second fixed mold 53 is formed. An inclined portion 75 on the side of the second fixed mold 53 facing the inclined portion 73 is formed between the parting surface 53a and the recessed portion 53b, and between the movable mold 51 and the first fixed mold 52, A first communication channel 76 for injecting the first resin injected from the first gate 57 into the first cavity 54 is formed, and the second gate 66 is provided between the movable mold 51 and the second fixed mold 53. Second communication flow for injecting the second resin injected from the second cavity 64 77 may be configured to have been formed.

(9) Although two-color molding using two resins having different colors has been described as an example, the resin for primary molding and the resin for secondary molding need not necessarily have different colors. For example, it is also possible to use multilayer molding in which a resin of the same color that is both transparent is used and a decorative sheet is sandwiched between these resins. Furthermore, it is also possible to use resins of the same kind and color as the resin for primary molding and the resin for secondary molding.

  When forming the second resin layer by injecting resin into the cavity disposed on the other surface of the intermediate layer fused with the first resin layer, it is possible to suppress gate jump of the intermediate layer and remelting of the primary molded product. It can be provided to the industry as a multilayer molding technology.

1, 31, 51, 181 Movable type 3, 33, 52, 182 First fixed type 7, 37, 53, 183 Second fixed type 2, 32, 54, 132 First cavity 6, 36, 64, 136 Second Cavity 4, 34, 44 First resin layer 23, 43 Second resin layer 5, 35, 56 Decorating sheet (decorating layer, intermediate layer)
5a, 35a, 45a, 45b, 56a Projection piece 5b, 35b Edge 11, 39, 66, 138, 139 Gate 12 Decorative film (decorative layer)
16 Clamp 17 Fixing means 19, 38, 71, 132a, 136a Auxiliary cavity 142X Retraction portion (stepped recess)
F1 Primary molded product F2 Secondary molded product

Claims (11)

A method for producing a multilayer molded article comprising a first resin layer and a second resin layer arranged with a decorative sheet interposed therebetween,
A first step of providing a primary molded product in which the first resin layer is fused to one side of the decorative sheet;
A second step of injecting resin into a cavity disposed on the other surface of the decorative sheet to form the second resin layer,
On the outer periphery of the decorative sheet, a protruding piece that protrudes to the outside of the multilayer molded product and contacts the support mold of the primary molded product is formed.
In the second step, the resin is injected into the cavity through a channel facing the protruding piece.   The manufacturing method according to claim 1, wherein in the second step, the resin is injected in a state where an edge portion of the protruding piece is fixed.   2. The manufacturing method according to claim 1, wherein in the second step, resin is injected along an extending direction of the protruding piece in a state where the flow path facing the protruding piece is connected along the cavity. .   In the second step, the cavity is formed between the decorative sheet supported by the first mold and the decorative film disposed on the inner surface of the second mold, and the decorative film is the first The manufacturing method according to claim 3, wherein the resin is injected in a state where a clamp fixed to the two molds is provided at a position in contact with a base end portion of the protruding piece.   5. The resin according to claim 1, wherein in the second step, the resin is injected in a state in which a tip of the protruding piece formed on the decorative sheet is retracted into a stepped recess provided in the support mold. The manufacturing method according to one item. A mold set for a multilayer molded article having a first resin layer and a second resin layer arranged with a decorative sheet interposed therebetween,
A first mold capable of supporting a primary molded product in which the first resin layer is fused to one side of the decorative sheet;
A second mold for forming a cavity for the second resin layer on the other surface side of the decorative sheet,
The first mold includes a support portion that supports the protruding pieces formed on the outer peripheral portion of the decorative sheet in contact with each other when the first mold and the second mold are clamped. And
A mold set in which a flow path for injecting resin into the cavity includes a portion facing the protruding piece. The mold set according to claim 6, wherein a pressing portion is provided between the first mold and the second mold so as to sandwich and fix an edge of the protruding piece based on the mold clamping .   The mold set according to claim 6, wherein the first mold includes fixing means for fixing an edge of the protruding piece to the first mold. The mold set according to claim 6, wherein a portion of the flow path facing the protruding piece is linearly connected to an inlet portion of the cavity.   The cavity is formed between the decorative sheet supported by the first mold and the decorative film disposed on the inner surface of the second mold, and the decorative film is fixed to the second mold. The mold set according to claim 9, wherein a clamp is provided at a position in contact with a base end portion of the protruding piece.   The mold set according to any one of claims 6 to 10, wherein a stepped recess that receives a tip of the protruding piece formed on the decorative sheet is provided in the first mold.

Images