JP2007216668A - Multilayered molding, method for molding, and apparatus for molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayered molding capable of obtaining a multilayered resin molded article by a small number of processes, and a method and an apparatus for molding the same. <P>SOLUTION: The multilayered molding is constituted by forming a finished layer which is created in such a manner that a molten resin is overlaid on one side of a sandwich molding which is sandwich-molded and thereafter cooled as it is. The method for molding the multilayered product comprises injecting a first resin which becomes a skin layer into a cavity 12 of a mold provided with a slide mold capable of varying a volume of the cavity, thereafter sandwich-molding by injecting a second resin which becomes a core layer, and successively injecting a third resin into a room obtained by expanding the volume of the cavity 12 by transferring the slide mold. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multilayer molded article, a molding method, and a molding apparatus.

  Resin multilayer molded products are used in various applications as composite materials that take advantage of the characteristics of each layer material. Among them, those having a cushion layer are growing in demand especially as materials for automobiles. As conventional techniques for multilayer molded products, there are disclosed a composite panel for buffering by vacuum forming (for example, see Patent Document 1) and a skin forming method by integral foaming combining slash and foaming (for example, see Patent Document 2). Has been. However, in these methods, since the base material is separately molded and integrated with the skin layer and the cushion layer, the number of manufacturing steps is increased and the manufacturing cost is increased.

  Moreover, in the manufacturing method (for example, refer patent document 3) of a cushioning composite molded product, the hard resin molded product shape | molded previously is inserted in the metal mold | die which has a space | gap larger than a hard resin molded product, and then foamable. It is disclosed that after a rubber-like elastic body is injected into a gap and the inside of a mold is completely filled, the inside of the mold is expanded to foam a foamable rubber-like elastic body.

  However, in this method, since the skin layer of the hard resin molded product is softened at the time of foaming, there is a problem that the pattern is crushed by the pressure of the foamed layer and the radiant power of the resin forming the base material. Moreover, even if it is going to obtain predetermined | prescribed board thickness by movement of a metal mold | die, since a foaming speed differs in each location, control is difficult. Further, this method does not obtain a four-layer molded product.

  On the other hand, as a three-layer molded article in which a foam layer is disposed in the gap between the skin layer and the base material, it is disclosed that the base material and the skin material are separately formed and a foamed resin layer is formed in the gap. . (For example, refer to Patent Document 4). In this manufacturing method, three steps of a base material forming step, a skin layer forming step, and a foam layer forming step are required, and there is a problem that a high manufacturing cost is required due to a large number of manufacturing steps. In principle, this manufacturing method can be applied to the manufacture of a four-layer molded product, but in this case, the number of manufacturing steps is further increased.

  Further, a method is disclosed in which a sandwich molding method and a sheet insert molding method are combined and a cushioning sheet is used as a sheet to be inserted (see, for example, Patent Documents 5 and 6). Although it can be obtained by two-stage injection, it takes time and effort to form a sheet to be inserted in advance and mount it on a mold.

  Furthermore, after filling the mold mold cavity with the primary molten resin and forming the molded product design surface, expand the mold cavity volume, inject the secondary molten resin to the back side of the design surface, and inject gas. A method for producing a composite molded product is disclosed in which a hollow part is formed at a desired location in the secondary molten resin by performing (see, for example, Patent Document 7). Also, after the thermoplastic resin is injected into the injection mold cavity and the layer (I) is formed, the movable mold is retracted to expand the mold mold cavity, and the fiber contains fibers and has a melt expansion property. A method for producing a multilayer molded article is disclosed in which a resin is injected or injection-compressed and then expanded by expanding the mold cavity volume to form a layer (II) (see, for example, Patent Document 8).

However, both of these obtain a layered structure made of two kinds of resins, and a multilayered structure made of three kinds of resins cannot be obtained.
Japanese Patent Laid-Open No. 55-5817 Japanese Patent Publication No.5-1123 JP-A-6-234133 Japanese Patent Laid-Open No. 9-1582 No. 2001-232663 No. 2004-230595 2001-334539 No. 2001-9984

  An object of the present invention is to provide a multilayer molded article for obtaining a multilayer resin molded article with a small number of steps and a molding method thereof.

  The gist of the present invention lies in a multilayer molded article in which a finished layer is formed on one side of a sandwich-molded sandwich formed by laminating a molten resin and then cooling it as it is. .

  Further, the gist of the present invention is that a finishing layer made of a resin is laminated on a sandwich-molded sandwich molded body, and the resin constituting the skin layer of the sandwich-molded body is melted in the finished state. It is a multilayer molded article in which the joined surface between the finishing layer and the sandwich molded body is formed after being laminated on the layer and then cooled as it is.

  The gist of the multilayer molded article of the present invention is that the core layer of the sandwich molded body is formed of a foam material.

  Further, the gist of the present invention is a method for molding the multilayer molded article, wherein a first resin serving as a skin layer is injected into the cavity of a mold having a slide mold capable of changing the volume of the cavity. After that, the second resin that becomes the core layer is injected and sandwiched, and then the slide mold is moved to expand the volume of the cavity, and the third resin that becomes the finishing layer is formed in the space in the cavity. The present invention resides in a method for molding a multilayer molded product to be injected.

  Furthermore, the gist of the present invention is a method for molding the multilayer molded article, in which a resin A serving as a finishing layer is injected into the cavity of a mold having a slide mold capable of changing the volume of the cavity. After that, the slide mold is moved to expand the volume of the cavity, and the resin B serving as the skin layer is injected into the space in the cavity, and then the resin C serving as the core layer is injected and sandwich molding is performed. The molding method is as follows.

  Further, the gist of the molding method of the present invention is that the second resin to be the core layer after injecting the first resin to be the skin layer into the cavity of the mold having the slide mold capable of changing the volume of the cavity. The resin was injected to form a first sandwich molded body, and then the slide mold was moved to expand the volume of the cavity, and a third resin serving as a skin layer was injected into the space in the cavity. A fourth sandwich resin is formed by injecting a fourth resin to be the rear core layer.

  The gist of the multilayer molded article of the present invention is a multilayer molded article formed by the molding method, and is composed of the first sandwich molded article and the second sandwich molded article.

  The gist of the multilayer molded article of the present invention is that the core layer of the first sandwich molded body and the core layer of the second sandwich molded body are formed of a foam material.

  The gist of the molding apparatus of the present invention is that a mold having a slide mold capable of changing the volume of the cavity, and a first injection for injecting a first resin as a skin layer into the cavity of the mold. A unit, a second injection unit for injecting a second resin that becomes a core layer after injecting the first resin, and an inside of the cavity formed by moving the slide mold to enlarge the volume of the cavity A third injection unit that injects a third resin that becomes a skin layer into the space, and a fourth injection unit that injects a fourth resin that becomes the core layer after injecting the third resin. That is.

  According to the present invention, a four-layer resin molded product can be molded while being clamped, and in the production of a four-layer molded product, the manufacturing process is greatly shortened compared to the manufacturing method using the insert method, and the manufacturing cost is reduced. Can be reduced.

  According to the present invention, in the production of a multilayer molded product for obtaining a four-layer resin molded product, the adhesive strength between the outermost layer and the layer adjacent to the outermost layer is stronger than that in the manufacturing method using the insert method. The range of material selection for each layer is expanded.

  According to the present invention, different types of resins or resin groups that are difficult to be melt-mixed and injected and molded as a mixed resin can be integrally molded by sandwich molding while being clamped.

  The multilayer molded product and the molding method of the present invention will be described. In the present invention, a first resin to be a skin layer is injected into a cavity of a mold having a slide mold capable of changing the volume of the cavity, and then a second resin to be a core layer is injected and sandwich-molded. Then, the third resin is injected into a space in the cavity formed by moving the slide mold to enlarge the volume of the cavity to obtain a multilayer molded product.

  In sandwich molding, first, a resin material that forms the outer layer is injected into the cavity, then a resin material that forms the inner layer is injected inside the resin material layer, and these resin materials are cooled and solidified to cool the outer layer. This is a molding for forming a resin molded body having a three-layer structure in which an inner layer is formed.

  In the present invention, for example, a molding apparatus 2 as shown in FIG. 1 is used. In addition, in this specification, the same code | symbol written over each figure shows the same or similar member and thing. The molding apparatus 2 has an injection cylinder 22 for injecting a fixed amount of the first resin (skin material), a skin flow path 4 for passing the first resin, and a fixed amount of second resin (core material). Core flow path 6 for passing the injection cylinder 24 and the first resin 7 to be transferred, and a shared first injection for injecting molten resin into the cavity 12 of the molding die 10 from both flow paths And a nozzle hole 14.

  Further, the molding apparatus 2 injects a fixed amount of the third resin 9 into the space of the cavity 12 formed by moving the slide mold 16 and expanding the volume of the cavity 12 by changing the volume of the cavity 12. And a finishing material flow path 11 for passing a third resin (finishing material) and a second injection nozzle hole 20 are provided.

  A procedure for molding the multilayer molded product of the present invention using the molding apparatus 2 will be described. In stage 1 (FIG. 2A), skin material 5 (first resin) is injected into cavity 12 through first injection nozzle hole 14, and then in stage 2 (FIG. 2B), The core material 7 (second resin) is injected into the skin material 5 through the first injection nozzle hole 14 to form a sandwich molded body 50. After the core material is injected, the slide mold 16 is moved in the stage 3 (FIG. 2C) to enlarge the volume of the cavity 12, and a space 18 is formed in the cavity 12. In the stage 4 (FIG. 2D), the finishing material 9 (third resin) is injected into the space 18 through the second injection nozzle hole 20.

  The first injection unit 30 for injecting the first resin is configured including the injection cylinder 22 and the skin flow path 4, and the second resin is injected including the injection cylinder 24 and the skin flow path 6. The second injection unit 32 is configured to include the injection cylinder 26 and the third material flow path 11, and the third injection unit 34 is configured to inject the third resin.

  FIG. 3 shows the structure of the multilayer molded product 40 obtained through such an operation stage. The multilayer molded product 40 is formed by laminating a finishing layer (third layer) 46 on one side of a sandwich molded body 50 composed of a core layer 44 whose front and back surfaces are covered with a skin layer 42. A part of the resin constituting the core layer 44 may be exposed to the outside from the skin layer 42 at, for example, the end portion of the core layer 44. As can be seen from the molding process described above, the finishing layer 46 is cooled as it is after the molten resin is laminated on one side of the sandwich molded body 50.

  Another aspect of the molding method and molding apparatus of the multilayer molded article of the present invention will be described. In this embodiment, after injecting the resin A as the finishing layer into the cavity of the mold having the slide mold capable of changing the volume of the cavity, the slide mold is moved to expand the volume of the cavity. A resin B as a skin layer is injected into the space, and then a resin C as a core layer is injected and sandwiched to obtain a multilayer molded product.

  In this embodiment, for example, a molding apparatus 2r as shown in FIG. 4 is used. The molding apparatus 2r includes an injection cylinder 22r for injecting a certain amount of skin material (resin B), a skin flow path 4r for passing the resin B, an injection cylinder 24r for injecting a certain amount of core material (resin C), and a resin. A core channel 6r for passing C, and a common injection nozzle hole 14r (injection nozzle hole A) for injecting molten resin into the cavity 12r of the molding die 10r from both channels. .

  The molding apparatus 2r includes a slide mold 16r capable of changing the volume of the cavity 12r, and includes a molding die 10r having an injection nozzle hole 14r and an injection nozzle hole 20r (injection nozzle hole B). Further, the molding apparatus 2r includes an injection unit 30r (injection unit A) capable of injecting a predetermined amount of the finishing material (resin A) in the cavity 12r through the injection nozzle hole 20r. Resin B serving as the skin layer and resin C serving as the core layer are injected into the space formed by moving the slide mold 16r to enlarge the volume of the cavity 12r.

  An injection unit 32r for injecting the resin B is configured including the injection cylinder 22r and the skin channel 4r, and an injection unit 34r for injecting the resin C is configured including the injection cylinder 24r and the skin channel 6r. An injection unit 30r for injecting the resin A is configured including the 26r and the finishing material flow path 11r.

  The molding procedure of the multilayer molded product of the present invention using the molding apparatus 2r will be described. In the stage 1 (FIG. 5A), the resin 9r (resin A) is injected into the cavity 12r through the injection nozzle hole 20r. Next, in the stage 2 (FIG. 5B), the slide mold 16r and the resin 9r that has been injected and molded are moved to enlarge the volume of the cavity 12r, thereby forming a space 18r in the cavity 12r. The injected and molded resin 9r is moved by gravity, adhesion force to the slide mold 16r, moving means such as pressure air blowing (not shown) or the injection pressure of the skin material 5r. In the stage 3 (FIG. 5C), the skin material 5r (resin B) is injected into the space 18r through the injection nozzle hole 14r, and then into the skin material 5r in the stage 4 (FIG. 5D). The core material 7r (resin C) is injected through the injection nozzle hole 14r to form a sandwich molded body 90.

  The shape of the multilayer molded product obtained through such an operation stage is the same as the shape of the multilayer molded product 40 shown in FIG. 3, and the sandwich molded body in which the finishing layer made of resin A is sandwich-molded is used. Although laminated, the resin B constituting the skin layer of the sandwich molded body is cooled while being laminated on the finishing layer in a molten state, so that a joining surface between the finishing layer and the sandwich molded body is formed.

  The multilayer molded product of the present invention can be generally block-shaped or plate-shaped. In particular, a curved plate can be suitably used as a structural material for automobiles, for example, interior materials such as instrument panels and door trims.

  As the core layer 44, for example, a foamed resin that foams immediately after injection can be used. Further, recycled resin may be regenerated and used. In many cases, the finishing layer 46 is a surface layer when a multilayer molded product is used, and importance is attached to the appearance and feel. Therefore, it is preferable to use a resin having cushioning properties such as an elastomer. Further, the surface may be provided with fine irregularities for the purpose of improving the texture. In the present invention, it is possible to prepare a mold having a surface for imparting such unevenness, and perform quick and easy lot change production by selecting one having various unevenness according to the application from various molds. be able to. Further, as the finishing layer 46, a material having performance according to applications such as improvement in appearance and feel and surface strength can be selected, and molding can be easily performed without taking the trouble of the insert method. Further, by changing the material, it is possible to quickly and easily change the production of lots of various products having the finishing layers 46 having different properties.

  As the skin layer 42 and the finishing layer 46, a resin having excellent color developability may be used depending on the application. Furthermore, a high-hardness resin having excellent scratch resistance may be selected. A transparent resin may be selected.

  As the core layer 44, a hard resin such as polypropylene may be used when ensuring the rigidity of the panel. The skin layer 42 is preferably made of a resin that forms a thin and tough film.

  Further, recycled resin may be used for the core layer 44. In this case, as the resin for the skin layer 42, a resin excellent in concealing property may be selected.

  Examples of the resin used for the core layer 44, the skin layer 42, and the finishing layer 46 include polyethylene resin, polypropylene resin, polystyrene resin, polyacryl styrene resin, ABS resin, AS resin, AES resin, ASA resin, SMA resin, poly General-purpose plastics typified by alkyl methacrylate resin, polyphenylene ether resin, polyacetal resin, polycarbonate resin, aromatic polyester resin, polyamide resin, cyclic polyolefin resin, polyarylate resin (amorphous polyarylate, liquid crystalline polyarylate), etc. So-called super engineering such as engineering plastics, polyether ether ketone, polyether imide, polysulfone, polyether sulfone, polyphenylene sulfide It can also be used what is called a grayed plastics. Furthermore, thermoplastic elastomers such as styrene thermoplastic elastomers, olefin thermoplastic elastomers, polyamide thermoplastic elastomers, polyester thermoplastic elastomers, and polyurethane thermoplastic elastomers can also be used. You may mix and use these resin.

  Further, the resin used for the core layer 44, the skin layer 42, and the finishing layer 46 may include a phosphorous heat stabilizer such as a phosphite compound, an antioxidant such as a phenolic antioxidant, benzophenone, if necessary. You may mix | blend ultraviolet absorbers and light stabilizers, such as a system ultraviolet absorber.

  Furthermore, the resin used for the core layer 44, the skin layer 42, and the finishing layer 46 has an increased amount, increased specific gravity, electrical conductivity, shielding against electromagnetic waves, enhanced strength, flame resistance, antibacterial, photocatalytic antifouling, and impact modification. A resin containing a substantial amount of filler may be employed for the purpose of quality, heat resistance, and the like. As fillers, talc, mica, clay, calcium carbonate, glass beads, carbon beads, glass balloons, carbon flakes, glass fibers, carbon fibers, ceramic fibers, aramid fibers, metal fibers, metal coated glass fibers, metal coated carbon fibers, Flame retardants such as silica, ceramic particles, carbon black, whiskers, halogens and phosphate esters, antistatic agents, flow modifiers, crystal nucleating agents, antibacterial agents, impact modifiers such as graft rubber, etc. Can be mentioned. In particular, when it is necessary to include a large amount of inorganic filler, it is preferable to include it in the resin of the core layer 44.

  In addition, the resin used for the core layer 44, the skin layer 42, and the finishing layer 46 has pigments, dyes, phosphorescent pigments, fluorescent pigments, fluorescent dyes, bluing agents, light for the purpose of light diffusion, coloring, and fluorescent whitening. A diffusing agent (acrylic resin particles, silicone resin particles, glass flakes, calcium carbonate particles, metal flakes, metal-coated glass flakes, etc.) may be added.

It is preferable that the resins constituting the two layers to be in contact with each other are selected so as to be compatible with each other. However, when selection is restricted due to the required characteristics of the product, a compatibilizing solvent may be mixed in each or either of them. Can be used.

  Further, in the present invention, since the finishing layer is bonded to the skin layer in a molten state, the adhesive strength between the two layers can be increased compared to the manufacturing method using the insert method, and the range of material selection is large. Become. In particular, the insert method can be used for welding between different materials by purchasing the resin that forms the skin layer, or by purchasing the compatibilizer for each of the resin that forms the skin layer and the resin that forms the finishing layer. Compared with the manufacturing method used, the adhesive strength between both layers can be further increased.

  Furthermore, in the present invention, the skin layer, the core layer on the front and back of the skin layer, and the finishing layer are formed simultaneously. Therefore, there is no need to mold the finishing layer in advance, and there is naturally no operation to mount the molded finishing layer on the mold, so the manufacturing process is greatly reduced compared to the manufacturing method using the insert method. Cost can be reduced. In the present invention, the finishing layer may be composed of a skin layer and a core layer.

  In the present invention, since the sandwich structure and the finishing layer are simultaneously beaten in one cycle, and one of them is in a molten state at the time of joining at the joining surface, the difference in thermal contraction between the two is relaxed at the time of joining, and the product warps. Is unlikely to occur.

  The multilayer molded article of the present invention can be suitably used as an interior material such as a vehicle instrument panel and a door trim by taking advantage of the feature. For example, a two-color sandwich structure in which a skin layer using PP or ABS (acrylic / butadiene / styrene resin) includes a core layer having excellent heat insulation and soundproofing properties such as foamed PP, an elastomer having excellent tactile sensation, etc. An interior material made of a three-color composite molded product with a functional material as the skin can be obtained with a single mold in a one-cycle injection molding process.

  Furthermore, the use of the multilayer molded product of the present invention includes a body of a home appliance such as an air conditioner or a television. As an example of a three-color composite molded product used for this, other materials having a surface decoration pattern such as various logos are added to a two-color sandwich structure combining a skin material and a core material for exhibiting design properties. A three-color composite molded product provided by a one-cycle injection molding process with a single mold.

  Furthermore, the use of the multilayer molded article of the present invention includes structural members such as furniture, tools, and machinery. As an example, the armrest of a chair type massage machine, the body body has excellent tactile sensation in a sandwich structure made of a skin material made of ABS or the like and a core material formed by adding a foaming agent in order to achieve rigidity and light weight. A member made of a three-color composite molded product using a functional material such as an elastomer as a surface cover layer can be obtained with a single mold in a one-cycle injection molding process.

  A vehicle door trim structure model assuming a vehicle door trim was formed by the apparatus shown in FIG. The mold is manufactured according to the shape of the vehicle door trim, and PP (polypropylene resin) (Novatech PP BC02A manufactured by Nippon Polychem Co., Ltd.) is used as the first resin (skin material) 195 with the screw of the extruder connected to the injection cylinder 22 Melted at 0 ° C. PP scrap resin as a second resin (core material) was melted at 200 ° C. with a screw of an extruder connected to the injection cylinder 24. Skin material 5 (first resin) is injected into cavity 12 through first injection nozzle hole 14, and then core material 7 (first resin) is injected into skin material 5 through first injection nozzle hole 14. Second resin) was injected to form a sandwich molded body 50. After the core material is injected, the slide mold 16 is moved to enlarge the volume of the cavity 12 and the finishing material 9 (third resin) is passed through the second injection nozzle hole 20 into the space 18 formed in the cavity 12. Ejected.

  An elastomer (Kuraray Septon CJ001N) was used as the finishing material 9 (third resin) which is a skin material. The third resin was melted at 220 ° C. with the screw of an extruder connected to the injection cylinder 26.

  After injection of the third resin, the mold was cooled and opened to obtain a vehicle door trim structure model composed of a three-color four-layer composite molded body containing PP scrap and having an elastomer skin.

  A three-color composite material colored plate was molded by the molding apparatus 2g shown in FIG. The molding apparatus 2g includes an injection cylinder 22g for injecting a certain amount of skin material (resin B) and a skin flow path 4g for delivering the resin B, an injection cylinder 24g for injecting a certain amount of core material (resin C), and a resin. A core flow path 6g for passing C and a common injection nozzle hole 14g for injecting molten resin into the cavity 12g of the molding die 10g from both flow paths are provided.

  The molding device 2g includes a molding die 10g. The molding die 10g has a first slide die 16g and a second slide die 16gg capable of changing the volume of the first cavity 12g, and has an injection nozzle hole 14g and an injection nozzle hole 20g (injection nozzle hole B). Have. Further, the molding apparatus 2g includes an injection cylinder 26g for injecting a predetermined amount of the finishing material (resin A) through the injection nozzle hole 20g and a flow path 8g for passing the resin A through the cavity 12g.

  Resin B serving as the skin layer and resin C serving as the core layer are injected through the injection nozzle hole 14g into the space formed by moving the slide mold 16g and the slide mold 16gg to enlarge the volume of the cavity 12g.

  In the molding die 10g, a second cavity 12gg surrounded by the first slide die 16g, the second slide die 16gg, and the main body 52g of the molding die 10g is formed.

  The three-color composite material decorative plate was molded by the molding apparatus 2g according to the following procedure. First, in stage 1 (FIG. 7A), resin 9g (resin Ag) was injected into cavity 12gg through injection nozzle hole 20g. As the decorative resin Ag, a polystyrene colored resin (MW-1C manufactured by Toyo Styrol Co., Ltd.) was used. After a cooling time of 5 seconds, the stage 2 (FIG. 7B) is moved to, and the slide mold 16g, the slide mold 16gg and the resin 9g injected and moved are moved to expand the volume of the cavity 12g to the cavity 12g. A space 18g was formed. In this movement, the slide mold 16g was moved downward as viewed in the drawing, and the slide mold 16gg was moved so that the upper surface thereof was substantially flush with the upper surface of the slide mold 16g. This movement may be a movement in a state where the relative positions of the slide mold 16g, the slide mold 16gg, and the resin 9g injected and molded do not change.

  The injected and molded resin 9g moves due to gravity or an adhesive force with the slide die 16gg, and is placed on the upper surface of the slide die 16gg.

  In stage 3 (FIG. 7C), skin material 5g (resin Bg) is injected into space 18g through injection nozzle hole 14g, and then in stage 4 (FIG. 7D), into skin material 5g. The core material 7g (resin Cg) was injected through the injection nozzle hole 14g to form a sandwich molded body 90g. As the resin Bg, a polystyrene transparent resin (MW-1C manufactured by Toyo Styrol Co., Ltd.) was used. As the resin Cg, a polystyrene-based colored resin (MW-1C manufactured by Toyo Styrol Co., Ltd.) was used.

  After forming 90 g of the sandwich molded body, the mold was opened with a cooling time of 30 seconds to obtain a three-color composite material decorative plate. The sandwich molded body 90g has a molded body 102g made of resin Ag in close contact with the outer side of the resin Bg formed as a transparent skin layer 104g, and the core layer 100g made of resin Cg avoids the molded body 102g and the skin layer 104g. It flows inside. This three-color composite material decorative plate is composed of a layer portion (1) in which one colored molded body (resin B) is present in a transparent resin (resin C), and another colored molded body (resin A). The layer part (2) has a combined structure, the part (2) bites into the part (1), and the exposed surface of the part (2) and the exposed surface of the part (2) It becomes the structure which becomes the same. Thus, according to the present invention, a three-color composite material decorative plate (sandwich molded body 90g) composed of a layered panel having two types of zones having different appearance hues when viewed from above is obtained. The surface of one zone is the surface of the portion (1), and one colored molded body (resin B) is seen through the transparent resin (resin C), and the surface of the other zone is the other colored surface. It is the surface where the molded body (resin A) is exposed. In addition, the surface of the core layer 100g, which is the skin of the sandwich molded body 90g, is an uneven surface (not shown) that displays a pattern such as a logo.

  Next, an embodiment using the multilayer molded article 200, the molding method for molding the multilayer molded article 200, and the molding apparatus 202 for molding the multilayer molded article 200 will be described as the multilayer molded article, molding method and molding apparatus of the present invention. To do. As shown in FIG. 8, the molding apparatus 202 injects a mold 208 including a slide mold 206 capable of changing the volume of the cavity 204, and a first resin 211 serving as the skin layer 210 into the cavity 204 of the mold 208. The first injection unit 212, the second injection unit 216 that injects the second resin 215 that becomes the core layer 214 after injecting the first resin 211, and the slide mold 206 are moved to increase the volume of the cavity 204. A third injection unit 220 for injecting the third resin 219 to be the skin layer 218 into the space in the enlarged cavity 204, and a fourth resin to be the core layer 222 after injecting the third resin 219. A fourth injection unit 224 for injecting 223.

  As the first resin 211, PP (polypropylene) virgin material (Prime Polymer Co., Ltd., grade J-3056HP) is used, and as the second resin 215, PP recycled material is used. As the resin 219, a TPE (thermoplastic elastomer) virgin material (Kakuichi Kasei Co., Ltd., grade E201260) is used. As the fourth resin 223, a TPE foam material (manufactured by Sankyo Kasei Co., Ltd., grade) is used. MB3066) was used. TPE foam material was blended with 3% foaming agent.

  First, the first injection unit 212 was operated, and the first resin 211 was injected into the cavity 204 as shown in FIG. As shown in FIG. 12, the first resin 211 was formed at a resin temperature of 190 ° C. and an injection speed of 4.7 mm / sec. Next, the first injection unit 212 and the second injection unit 216 are operated to inject the first resin 211 and the second resin 215 as shown in FIG. A core layer 214 was formed. As shown in FIG. 12, the resin temperature of the first resin 211 was 190 ° C., the injection speed was 17 mm / sec, the resin temperature of the second resin 215 was 180 ° C., and the injection speed was 9.3 mm / sec.

  Next, the slide mold 206 is moved to enlarge the volume of the cavity 204 as shown in FIG. 9C, and the third injection unit 220 is operated, as shown in FIG. A third resin 219 was injected into the cavity 204. As shown in FIG. 12, the third resin 219 was performed at a resin temperature of 220 ° C. and an injection speed of 5.7 mm / sec. Next, the third injection unit 220 and the fourth injection unit 224 are actuated to inject the third resin 219 and the fourth resin 223 as shown in FIG. ), The skin layer 218 and the core layer 222 were formed.

  As a result, as shown in FIG. 11, a multilayer molded article 200 composed of the first sandwich molded body 226 and the second sandwich molded body 228 was formed. The adhesive strength between the first sandwich molded body 226 and the second sandwich molded body 228 was high. This is considered due to the fact that the first sandwich molded body 226 and the second sandwich molded body 228 were continuously molded by a single mold 208. Moreover, since the core layer 222 was softer and more elastic than the skin layer 218, the second sandwich molded body 228 had a good feel when held by hand. Further, since the skin layer 218 is harder than the core layer 222, surface wear and damage can be prevented. By utilizing such a molding method of the present invention, a core layer made of an elastic body can be formed only on a necessary portion of a resin molded product, and the multilayer molded product thus formed is used as an interior part of an automobile. Is optimal. Further, if the skin layer on the surface side of the multilayer molded product is formed from a virgin material and the core layer is formed from a recycled material, the cost can be reduced as compared with the case where the whole is formed from a virgin material.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

  For example, as a method for injecting the resin of the skin layer and the resin of the core layer, sequential injection, simultaneous injection, or a combination of sequential injection and simultaneous injection can be used as appropriate. In the multilayer molded article of the present invention, the core layer may be formed softer or harder than the skin layer.

  In the method and apparatus for molding a multilayer molded article of the present invention, a method using a single injection cylinder can be used in addition to a method using a plurality of cylinders with the injection cylinder independent of each resin. In the case of a single injection cylinder, the skin layer resin and the core layer resin are separated and accumulated in the front and rear chambers with a movable mandrel, and the skin layer resin is filled into the mold by injection. Thereafter, there is a movable mandrel method in which the resin of the core layer is filled from the hole at the tip of the movable mandrel. Also, the resin of the skin layer is extruded from the auxiliary device and can be accumulated in the injection device by a switching valve in the hot runner, and then accumulated, the resin of the core layer is plasticized by the injection device, the resin of the skin layer and the core layer The mono-sandwich method can be used in which the resin can be filled in the mold by a switching valve or the like in the hot runner after the resin is accumulated in the injection apparatus, and any method can be used in the present invention. it can. In this case, the first injection unit and the second injection unit in the present invention also serve as a part of the parts.

  In the case of using a plurality of cylinders, the resin of the skin layer and the resin of the core layer are formed in a layer structure by using a merging nozzle where the skin flow path 4 and the core flow path 6 merge, as well as in the gate portion in the mold, etc. A method of merging can also be used. When using a merge nozzle, either a parallel type nozzle or a V type nozzle can be used, and a concentric double tube type can be used as the internal structure of the nozzle. Alternatively, a method of controlling the flow of resin in the merging nozzle using a blocking pin can be used. Further, the number of resin layers in the nozzle is basically a two-channel type, but a three-channel type or more that can be further multilayered can be used.

  Moreover, in the multilayer molded article 40 of FIG. 3, the core layer 44 of the sandwich molded body 50 may be formed from a foam material that is a virgin material or a recycled material. In this case, for example, the skin layer 42 is formed from a PP virgin material, and the finishing layer 46 is formed from an elastomeric cosmetic material. That is, the core layer is selected from any one of four modes: a foamed material of virgin material, a normal material of virgin material, a foamed material of recycled material, or a normal material of recycled material. In the multilayer molded article 200 of FIG. 11, the core layer 214 may be formed of a foam material that is a virgin material or a recycled material. In this case, for example, the skin layer 218 is formed from an elastomeric cosmetic material, the core layer 222 is formed from a foamed material or an elastomeric recycled material that is a virgin material or a recycled material, and the skin layer 210 is formed from a PP virgin material. . Further, the multilayer molding method or multilayer molded article of the present invention may be an embodiment in which the above-described skin layer or finishing layer is made of a foam material.

It is a schematic diagram which shows an example of the aspect of the shaping | molding apparatus which shape | molds the multilayer molded article of this invention. It is a figure explaining the step of manufacture of the multilayer molded article of this invention. It is a cross-sectional schematic diagram which shows the structure of the multilayer molded product of this invention. It is a schematic diagram which shows an example of the other aspect of the shaping | molding apparatus which shape | molds the multilayer molded article of this invention. It is a figure explaining the step of manufacture of the multilayer molded article of this invention by the shaping | molding apparatus shown in FIG. It is a schematic diagram which shows an example of the further another aspect of the shaping | molding apparatus which shape | molds the multilayer molded article of this invention. It is a figure explaining the step of manufacture of the multilayer molded article of this invention by the shaping | molding apparatus shown in FIG. It is a schematic diagram which shows an example of the further another aspect of the shaping | molding apparatus which shape | molds the multilayer molded article of this invention. It is a figure explaining the step of manufacture of the multilayer molded article of this invention by the shaping | molding apparatus shown in FIG. It is a figure explaining the step of manufacture of the multilayer molded article of this invention by the shaping | molding apparatus shown in FIG. It is a cross-sectional schematic diagram which shows the structure of the multilayer molded product of this invention by the shaping | molding apparatus shown in FIG. It is a table | surface which shows the conditions of the shaping | molding test by the shaping | molding apparatus shown in FIG.

Explanation of symbols

2, 2r, 2g, 202: molding device 5, 211: first resin (skin material)
4: Skin channel 6: Core channel 7, 215: Second resin (core material)
9: Third resin (third material)
10, 208: Mold 11: Third material flow path 12: Cavity 14: First injection nozzle holes 16, 16r, 16g, 16gg, 206: Slide mold 20: Second injection nozzle holes 22, 22r, 22g , 24, 24r, 24g, 26, 26r, 26g: injection cylinders 30, 30r, 30g, 212: first injection units 32, 32r, 32g, 216: second injection units 34, 34r, 34g, 220: first Three injection units 40, 200: Multilayer molded articles 42, 210, 218: Skin layers 44, 214, 222: Core layer 46: Finishing layers 50, 226, 228: Sandwich molded body 219: Third resin (skin material)
223: Fourth resin (core material)
224: Fourth injection unit

Claims (9)

A multilayer molded article in which a molten resin is laminated on one side of a sandwich-molded sandwich molded body and a finished layer is then cooled as it is. A resin-made finishing layer is laminated on a sandwich-molded sandwich molded body, and the resin constituting the skin layer of the sandwich-molded body is laminated on the finishing layer in a molten state and then cooled as it is, A multilayer molded article in which a joining surface between the finishing layer and the sandwich molded body is formed. The multilayer molded article according to claim 1 or 2, wherein the core layer of the sandwich molded body is formed of a foam material. A method for molding a multilayer molded article according to claim 1, wherein a core layer is formed after injecting a first resin serving as a skin layer into the cavity of a mold having a slide mold capable of changing the volume of the cavity. A multilayer molded product in which a second resin is injected, sandwich molded, and then the slide mold is moved to expand the volume of the cavity to inject a third resin as a finishing layer into a space in the cavity. Molding method. 3. A method of molding a multilayer molded article according to claim 2, wherein after the resin A serving as a finishing layer is injected into the cavity of a mold having a slide mold capable of changing the volume of the cavity, the slide mold is moved. A method for forming a multilayer molded article, in which a resin B serving as a skin layer is injected into a space formed by enlarging the volume of the cavity and then a resin C serving as a core layer is injected and sandwiched. A first sandwich molding is formed by injecting a first resin as a skin layer into the cavity of a mold having a slide mold capable of changing the volume of the cavity, and then injecting a second resin as a core layer. Then, after moving the slide mold and expanding the volume of the cavity, the third resin that becomes the skin layer is injected into the space in the cavity, and then the fourth resin that becomes the core layer is injected and the second resin is injected. A molding method for forming a second sandwich molded body. A multilayer molded article formed by the molding method according to claim 6,
A multilayer molded article comprising the first sandwich molded body and the second sandwich molded body. The multilayer molded article according to claim 7, wherein one or both of the core layer of the first sandwich molded body and the core layer of the second sandwich molded body are formed of a foam material. A mold having a slide mold capable of changing the volume of the cavity;
A first injection unit for injecting a first resin as a skin layer into the cavity of the mold;
A second injection unit for injecting a second resin to be a core layer after injecting the first resin;
A third injection unit for injecting a third resin as a skin layer into a space in the cavity formed by moving the slide mold and expanding the volume of the cavity;
A fourth injection unit for injecting a fourth resin to be a core layer after injecting the third resin;
A molding apparatus comprising:

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