JP6192101B2 - Skin material bonding structure for automotive interior parts and its skin material bonding method - Google Patents

Description

  The present invention relates to a skin material bonding structure for an interior part for automobiles, which is formed by bonding a skin material to a resin core material with a thermoplastic adhesive, and a method for bonding the skin material.

  FIG. 4 is a cross-sectional view of a conventional door trim (automobile interior part). The conventional door trim DT shown in the figure has a structure in which a skin material 2 is bonded to a resin core material 1 with a thermoplastic adhesive. And the skin material 2 before bonding to the resin core material 1 has the adhesive layer 3 of the thermoplastic resin on the back surface, and conventionally, the thermoplastic resin of the adhesive layer 3 on the back surface of the skin material 2 is used. The resin core material 1 and the skin material 2 are bonded together by melting with a predetermined heat.

  The conventional door trim DT of FIG. 4 can be formed by the first molding method shown in FIGS. 2A to 2D and FIGS. 3E and 3F, for example. When the conventional door trim DT of FIG. 4 is molded by the first molding method, the molten resin is injected into the cavity 10C of the molding die 10 shown in FIG. Thus, when the injection molding of the resin core material 1 is completed, the molding die 10 is brought into the mold open state by moving the pair of dies 10A, 10B away from each other by a predetermined amount as shown in FIG. The skin material 2 is set on the resin core material 1 as shown in FIG. Then, when the pair of molds 10A and 10B are relatively brought close to each other as shown in FIG. 3 (e) and the molding mold 10 is closed, the thermoplastic adhesive of the adhesive layer 3 is caused by the residual heat of the resin core material 1. The resin core material 1 and the skin material 2 are bonded together in a pressure-bonded state.

  For example, Patent Document 1 discloses a technique for bonding the resin core material and the skin material by melting the thermoplastic adhesive of the adhesive layer by the residual heat of the resin core material as described above.

  However, according to the conventional door trim DT of FIG. 4, as described above, the skin material 2 before being bonded to the resin core material 1 has a structure (see FIG. 4) having the adhesive layer 3 on the back surface thereof. There are problems like this.

<< First Problem (Adhesion of Thermoplastic Resin to Mold 10) >>
FIG. 5 is an explanatory view of a pressure bonding / cooling step (corresponding to FIG. 3E) when the conventional door trim DT of FIG. 4 is formed by the first molding method. Referring to FIG. 5, when the molding die 10 is closed as shown in FIG. 5, the thermoplastic adhesive of the adhesive layer 3 is melted by the residual heat of the resin core material 1. Then, the resin core material 1 and the skin material 2 are pressure-bonded and bonded together by the pressure applied to the melted thermoplastic adhesive and the skin material (specifically, the press pressure of the pair of molds 10A and BB). The At the time of bonding, the outer peripheral edge 2C of the skin material 2 protrudes outward from the outer peripheral edge of the resin core material 1, and the adhesive layer 3 of the protruding portion (2C) is in direct contact with the molding die 10 and pressure is applied. Therefore, there is a problem that the thermoplastic adhesive of the adhesive layer 3 is likely to adhere to the molding die 10 side.

  In addition, in order to prevent adhesion of the thermoplastic adhesive to the molding die 10 side as described above, a method of performing a treatment such as fluorine coating on the molding die can be considered, but this method is expensive. Management of fluorine coating is also troublesome.

  When the thermoplastic adhesive adheres to the molding die 10 side as described above, the thermoplastic adhesive of the adhesive layer 3 necessary for bonding the resin core material 1 and the skin material 2 decreases, and the resin core material 1 and There is a possibility that poor bonding occurs at the outer peripheral edge of the skin material 2. Further, if the protruding portion (2C) adheres to the molding die 10, the outer peripheral edge portion (the protruding portion (2C)) of the skin material 2 is near the molding die 10 when the development rate of the skin material 2 is large. There is a risk that the high expansion rate portion of the skin material 2 (the portion where the skin material 2 is most likely to extend) may be cut without slipping inside.

  Further, as described above, there may be a known resin seal mechanism in the portion of the adhesive layer 3 where the thermoplastic adhesive adheres to the molding die 10 side. That is, the molding die 10 to which the first molding method is applied is a resin slidable in the vertical direction in the molding die 10 as a means for preventing the generation of burrs when the resin core material 1 is injection molded. A sealing mechanism is provided. At the time of injection molding of the resin core material 1, the outer peripheral edge of the resin core material 1 is pushed upward by the front end surface of the resin seal mechanism. When the thermoplastic adhesive of the adhesive layer 3 is deposited and deposited, the normal operation of the resin seal mechanism is lost, and burrs are likely to occur in the injection molding of the resin core material.

《Second problem (problem in storage management of skin material)》
When a plurality of skin materials 2 before being bonded to the resin core material 1 are stacked and stored, the upper skin material adhesive layer 3 directly contacts the surface of the lower skin material due to the structure of the skin material 2. For this reason, the upper and lower skin materials may stick to each other and cannot be separated, and it is difficult to store and manage the skin materials before bonding.

JP 2010-179485 A

  The present invention has been made to solve the above-mentioned problems, and the object thereof is to effectively prevent adhesion of a thermoplastic adhesive to a molding die for molding an automobile interior part. An object of the present invention is to provide a skin material bonding structure for an automotive interior part and a method for bonding the skin material, which are suitable for facilitating the storage management of the skin material before being bonded to a resin core material.

  The method for bonding an automotive interior part skin material according to the present invention is a method for bonding an automotive interior part skin material obtained by bonding an outer skin material to a resin core material with a thermoplastic adhesive, the resin core material The skin material before being bonded to the surface has an adhesive layer of the thermoplastic adhesive on the back surface thereof, and a back surface nonwoven fabric layer made of a nonwoven fabric as an outer surface layer of the skin material back surface on the bottom surface of the adhesive layer, and the resin core material The method of laminating the skin material with respect to the contact stage of contacting the back nonwoven fabric layer side of the skin material to the resin core material, heat of the resin core material or heat of the skin material or both from the contact time Heat causes the thermoplastic adhesive of the adhesive layer to melt and soak into the back nonwoven fabric layer, and the soaked thermoplastic adhesive soaks into the resin core material due to the pressure applied to the skin material, and the heat that has soaked out. Plasticity Characterized in that it comprises a bonding step by the pressure and Chakuzai said resin core member and the back nonwoven layer side of the skin material are bonded together by crimping, a.

  In the method for laminating an automobile interior part according to the present invention, the nonwoven fabric may be a spunlace nonwoven fabric produced by a spunlace method.

  In the present invention, the following effects (A) and (B) can be obtained by adopting the above configuration.

(A) Prevention of Adhesive Adhesion to Molding Mold According to the present invention, as a specific configuration of the skin material before being bonded to the resin core material, such a skin material has an adhesive layer of a thermoplastic adhesive on its back surface. The back surface nonwoven fabric layer which consists of a nonwoven fabric was employ | adopted as a skin material back surface outermost layer on the lower surface of this contact bonding layer. For this reason, for example, even when the outer peripheral edge portion of the skin material protrudes outward from the outer peripheral edge portion of the resin core material at the time of bonding, the adhesive layer of the protruding portion is in direct contact with the molding die. Since the back nonwoven fabric layer always exists as a barrier between the adhesive layer and the molding die of the protruding portion, the thermoplastic adhesive is applied to the protruding portion even if pressure is applied due to the barrier effect of the back nonwoven layer. Can be effectively prevented from adhering to the molding die without adhering to the molding die.

  Further, in the present invention, since the adhesion of the thermoplastic adhesive to the molding die can be effectively prevented as described above, the above-described problems due to the adhesion of such a thermoplastic adhesive, that is, Further, it is possible to prevent the bonding failure at the outer peripheral edge portion of the resin core material and the skin material, the cut of the skin material, and the occurrence of burrs in the injection molding of the resin core material.

(B) Facilitating storage management of the skin material before bonding According to the present invention, the skin material before being bonded to the resin core has an adhesive layer of a thermoplastic adhesive on the back surface thereof, and A back surface nonwoven fabric layer made of a nonwoven fabric is provided on the bottom surface as the outermost layer of the skin material. For this reason, for example, when a plurality of skin materials before bonding are stacked and stored, the adhesive layer of the upper skin material does not directly contact the surface of the lower skin material, and the upper and lower skin materials are It can be easily separated by the back surface nonwoven fabric layer of the skin material, and the storage management of the skin material before bonding can be facilitated.

FIG. 1 is a cross-sectional view of a door trim that employs a skin material bonding structure for automobile interior parts according to the present invention. FIG. 2 is a process conceptual diagram of the door trim molding method (first molding method) shown in FIG. 1. FIG. 2 (a) is a schematic configuration diagram of a molding die (standby state) used for molding the door trim. (B) is explanatory drawing of the mold closing and resin injection process in a molding die, (c) is explanatory drawing of the primary mold opening process (a mold opening amount is small) in a molding die, (d) is in a molding die Explanatory drawing of a skin material setting process. FIG. 3 is a process conceptual diagram of the door trim molding method (first molding method) shown in FIG. 1, (e) is an explanatory view of the crimping and cooling process in the molding die, and (f) is in the molding die. Explanatory drawing of a secondary mold opening process (product taking-out process). Sectional drawing of the conventional door trim (automobile interior parts). Explanatory drawing of the crimping | compression-bonding and cooling process (corresponding to FIG.3 (e)) when shape | molding the conventional door trim of FIG. 4 by the 1st shaping | molding method.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of a door trim that employs a skin material bonding structure for automobile interior parts according to the present invention.

  The door trim DT of FIG. 1 is an interior part for an automobile in which a skin material 2 is bonded to a resin core material 1 with a thermoplastic adhesive. In the door trim DT of FIG. 1, the skin material 2 before being bonded to the resin core material 1 has an adhesive layer 3 of a thermoplastic adhesive on the back surface, and a back surface nonwoven fabric layer 4 made of a nonwoven fabric on the bottom surface of the adhesive layer 3. It has a structure with.

  The surface side of the skin material 2 is a skin layer 5, and a cushion layer 6 and an intermediate nonwoven fabric layer 7 made of a nonwoven fabric are provided between the skin layer 5 and the adhesive layer 3. .

  That is, in the door trim DT of FIG. 1, the skin material 2 before being bonded to the resin core material 1 with the thermoplastic adhesive is the back surface nonwoven fabric layer 4, the adhesive layer 3, the intermediate nonwoven fabric layer 7, and the cushion layer as viewed from the back surface side. 6. It has a five-layer structure in which the skin layer 5 is laminated in that order.

  Of the five-layer structure, the skin layer 5 is made of a skin material such as cloth, nonwoven fabric, or synthetic leather, and the cushion layer 6 is made of a foamed urethane material.

  The intermediate nonwoven fabric layer 7 is formed of, for example, a nonwoven fabric (spunlace nonwoven fabric) produced by a spunlace method (hydroentanglement method). The adhesive layer 3 employs an olefin-based hot melt adhesive (PP, PPC, etc.) having a melting temperature of 100 ° C. to 160 ° C. as the thermoplastic resin constituting the layer, and the back surface nonwoven fabric layer 4 is formed of a spunlace nonwoven fabric in the same manner as the intermediate nonwoven fabric layer 7 described above. The olefinic hot melt adhesive (PP, PPC, etc.) employed in the present embodiment is a material that is difficult to adhere to the cushioning layer 6 made of urethane foam, and therefore in this embodiment, between the cushioning layer 6 and the adhesive layer 3. A nonwoven fabric is interposed as the intermediate nonwoven fabric layer 7. Therefore, when a material that is easily bonded, for example, a polypropylene foam of the same material as the olefin-based hot melt adhesive (PP, PPC, etc.) is employed as the cushion layer 6, the intermediate nonwoven fabric layer 7 may be omitted.

  By the way, the intermediate nonwoven fabric layer 7 is provided as a means for preventing deterioration of cushion performance due to excessive penetration of the thermoplastic adhesive of the adhesive layer 3 into the foamed urethane material of the cushion layer 6 at the time of melting. Therefore, if the cushion layer 6 is formed of a material that is unlikely to cause such a decrease in cushion performance, for example, polypropylene foam (PPF), the intermediate nonwoven fabric layer 7 can be omitted.

  In the door trim DT of FIG. 1, the bonding structure of the skin material 2 to the resin core material 1 is such that the heat of the resin core material 1 or the resin core material 1 from the time when the back surface nonwoven fabric layer 4 side of the skin material 2 is brought into contact with the resin core material 1. The thermoplastic adhesive of the adhesive layer 3 is melted by the heat of the skin material or both, and soaks into the back nonwoven fabric layer 4, and the pressure applied to the skin material 2 (specifically, the soaked thermoplastic adhesive) ) And the back surface of the resin core material 1 and the skin material 2 by the exuded thermoplastic adhesive and the pressure. It is in the state where the nonwoven fabric layer 4 side was pressure-bonded and bonded.

  In the present embodiment, the residual heat of the resin core material 1 is adopted as the heat of the resin core material 1 when the thermoplastic adhesive of the adhesive layer 3 is melted as described above. That is, the door trim DT of FIG. 1 can be formed by a first molding method (see FIGS. 2A to 2D and FIGS. 3E to 3F) described later. In the case of the first molding method, when the molding of the resin core material 1 is completed by injection molding, the heat at the time of melting the resin remains in the resin core material 1 as residual heat (80 ° C. to 150 ° C.). Thus, in the present embodiment, in the case where the door trim DT is molded by the first molding method, the thermoplastic adhesive of the adhesive layer 3 is melted by the residual heat of the resin core material 1.

  Since the thermoplastic adhesive of the adhesive layer 3 in this embodiment is melted by the residual heat of the resin core 1 as described above, for example, when the surface temperature of the resin core 1 is in the temperature range of 80 ° C. to 150 ° C. A thermoplastic adhesive that melts in that temperature range is employed as the thermoplastic adhesive of the adhesive layer 3.

  Incidentally, the door trim DT of FIG. 1 can also be formed by a molding method (hereinafter referred to as “second molding method”) using a resin core material molded in advance as described later. However, in this second molding method, the temperature of the resin core material 1 before bonding the skin material 2 is substantially the same as the temperature of the molding die and is as low as 20 ° C. to 80 ° C., and the heat (residual heat) of the resin core material 1 ), It is difficult to melt the thermoplastic adhesive of the adhesive layer 3.

  For this reason, when the door trim DT of FIG. 1 is molded by the second molding method to be described later, the resin core material 1 is preheated by a heating device, and the heat of the resin core material 1 by this preheating (hereinafter referred to as “resin core”). The thermoplastic adhesive of the adhesive layer 3 is melted by the additional heat of the material 1), or the skin material 2 itself is heated in advance with a heating device, and the heat of the skin material 2 due to this heating (hereinafter referred to as “the skin material 2 The thermoplastic adhesive of the adhesive layer 3 may be melted by “additional heat”.

  The two types of heat of the resin core material 1 described above (residual heat of the resin core material 1 and additional heat) and the additional heat of the skin material 2 may be employed individually, or they may be appropriately selected as necessary. They can also be used in combination.

  In the door trim DT of FIG. 1, a non-woven fabric (spun lace non-woven fabric) produced by a spunlace method (hydroentanglement method) is adopted as a specific non-woven fabric constituting the back nonwoven fabric layer 4, but is not limited thereto. There is nothing. For example, a nonwoven fabric produced by various web forming methods such as a needle punch method, a dry method, a wet method, a melt blown method, or an air raid method can also be adopted as the nonwoven fabric 4. The same applies to the intermediate nonwoven fabric layer 7.

  FIG. 2 is a process conceptual diagram of the door trim molding method (first molding method) shown in FIG. 1. FIG. 2 (a) is a schematic configuration of a molding die (standby state) used for molding the door trim. (B) is an explanatory view of the mold closing and resin injection process in the molding die, (c) is an explanatory view of a primary mold opening process (the mold opening amount is small) in the molding die, and (d) is the same. It is explanatory drawing of the skin material setting process in a shaping die. 3 is a process conceptual diagram of the door trim molding method (first molding method) shown in FIG. 1, and FIG. 3 (e) is an explanatory view of the crimping / cooling process in the molding die. f) It is explanatory drawing of the secondary mold opening process (product taking-out process) in the molding die.

  When the door trim DT shown in FIG. 1 is formed by the first molding method, the molding die 10 shown in FIG. 2A whose temperature is adjusted to a temperature of 20 ° C. to 80 ° C. is used. The molding die 10 includes a pair of molds 10A and 10B that are opposed to each other in the vertical direction. The molding die 10 is brought into a closed state by bringing the pair of dies 10A and 10B relatively close to each other as shown in FIG. 2B by a driving device (not shown) and the pair of dies. A cavity 10C having a required shape is formed between 10A and 10B. The cavity 10C corresponds to the external shape of the door trim DT that is the final product.

  When the closing of the mold 10 is completed as shown in FIG. 2 (b), melting at 190 ° C. to 240 ° C. from the resin injection nozzle N of one mold 10A toward the cavity 10C as shown in FIG. 2 (b). Resin is injected and the resin core material 1 (see FIG. 2C) of the door trim DT is molded in the cavity 10C. When the molding of the resin core material 1 is completed by such injection molding, the heat at the time of resin melting remains as residual heat in the resin core material 1. The temperature of the residual heat is 80 ° C to 150 ° C.

  When the injection molding of the resin core material 1 is completed as described above, next, the residual heat of the resin core material 1 is not cooled, that is, the resin core material 1 can melt the thermoplastic adhesive of the adhesive layer 2. While holding the remaining heat, the pair of molds 10A and 10B are moved away from each other by a predetermined amount as shown in FIG. 2C, so that the mold 10 is opened and FIG. As shown in d), the skin material 2 is set on the resin core material 1. The set state of the skin material 2 is such that the back nonwoven fabric layer 4 side of the skin material 2 is in contact with the resin core material 1.

  Thereafter, when the pair of molds 10A and 10B are relatively brought close to each other as shown in FIG. 3 (e) and the molding mold 10 is closed, the thermoplastic adhesive of the adhesive layer 3 is caused by the residual heat of the resin core material 1. Is melted and soaked into the back nonwoven fabric layer 4, and the resin core material 1 is applied by the pressure (specifically, the press pressure of the pair of molds 10 </ b> A and 10 </ b> B) to which the soaked thermoplastic adhesive is applied to the skin material 2. The resin core material 1 and the back surface nonwoven fabric layer 4 of the skin material 2 are pressure-bonded and bonded together by the thermoplastic adhesive that has oozed out and the pressure.

  Referring to FIG. 3 (e), the outer peripheral edge 2C of the skin material 2 protrudes outward from the outer peripheral edge 1A of the resin core 1 during the bonding, but the adhesive layer of the protruding portion (2C) 3 is not in direct contact with the molding die 10, and the back nonwoven fabric layer 4 always exists as a barrier between the adhesive layer 3 at the protruding portion (2C) and the molding die 10. Due to this barrier effect, even if pressure is applied, the thermoplastic adhesive does not adhere to the molding die 10 at the protruding portion (2C).

  When the bonding is completed, the door trim DT shown in FIG. 1 is obtained in the molding die 10. In order to take out the door trim DT from the molding die 10, the pair of dies 10 </ b> A and 10 </ b> B may be relatively moved away from each other as shown in FIG.

  By repeating the operations described above, mass production of the door trim DT is performed. At this time, as described above, since the thermoplastic adhesive does not adhere to the molds 10A and 10B at the time of bonding, it is not necessary to remove the adhered thermoplastic adhesive. The production speed of the door trim DT is increased.

  Next, an example in which the door trim DT shown in FIG. 1 is formed by the second forming method will be described with reference to FIGS. 2 and 3. In this case, as in the first molding method described above, the molding die 10 shown in FIG. 2A adjusted to a temperature of 20 ° C. to 80 ° C. is used.

  In the second molding method, since the resin core material 1 is not injection-molded in the cavity 10C of the molding die 10 as in the first molding method, one mold 10A in the molding die 10 in FIG. The resin injection port N, the mold closing and resin injection process in FIG. 2B, and the primary mold opening process (the mold opening amount is small) in FIG. 2C are all omitted. Instead, in the second molding method, the separately prepared resin core material 1 is set in the lower mold 10A as shown in FIG. 2D, and the set resin core material 1 The work of setting the skin material 2 on top is performed. The set state of the skin material 2 is such that the back nonwoven fabric layer 4 side of the skin material 2 is in contact with the resin core material 1.

  The resin core material 1 and the skin material 2 set as described above are heated to near the same temperature (20 ° C. to 80 ° C.) as the molding die 10 by the heat of the molding die 10, but at that temperature, the adhesive layer 3. It is difficult to melt the thermoplastic resin. For this reason, in the second molding method, as a means for obtaining additional heat of the resin core material 1, the resin core material 1 is heated in advance to apply additional heat to the resin core material 1. At this time, as a means for imparting additional heat to the skin material 2, the skin material 2 may be preheated, or both the resin core material 1 and the skin material 2 may be preheated.

  After the setting of the resin core material 1 and the skin material 2 is completed as described above (see FIG. 2D), the pair of molds 10A and 10B are relatively brought close to each other as shown in FIG. The mold 10 is closed. Thereby, from the time of the back nonwoven fabric layer 4 side of the skin material 2 contacting the resin core material 1, the thermoplastic adhesive of the adhesive layer 3 is heated by the heat of the resin core material 1 and / or the heat of the skin material 2. It melts and soaks into the back nonwoven fabric layer 4, and the soaked thermoplastic adhesive oozes out to the resin core material 1 by the pressure applied to the skin material 2, and the squeezed thermoplastic adhesive and the resin core by the above pressure The material 1 and the back surface nonwoven fabric layer 4 side of the skin material 2 are pressure-bonded and bonded together.

  By the way, in the second molding method, as in the first molding method described above, the adhesive layer 3 of the protruding portion (2C) of the skin material 2 is in direct contact with the molding die 10 at the time of bonding. Since the back nonwoven fabric layer 4 always exists as a barrier between the adhesive layer 3 of the protruding portion 2C and the molding die 10, even if pressure is applied due to the barrier effect of the back nonwoven fabric layer 4, The thermoplastic adhesive does not adhere to the molding die 10 at the protruding portion (2C).

  Although the above embodiment is an example which applied the skin material bonding structure and the skin material bonding method of the interior component for motor vehicles concerning this invention to a door trim, it is not limited to this application example. The skin material pasting structure and the skin material pasting method for automotive interior parts according to the present invention are widely applied to automotive interior parts in which a skin material is pasted to a resin core material with a thermoplastic adhesive. Can do. Further, in the above embodiment, a method in which pressure is applied to the skin material 2 by placing the molding die 10 in a closed state is not limited to this, but in a different method. A pressure may be applied to the skin 2.

  The present invention is not limited to the embodiments described above, and many modifications can be made by those having ordinary knowledge in the art within the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Resin core material 1A Outer peripheral edge part 1B of resin core material Inner part 2 of resin core material Outer skin part 2A Outer peripheral edge part 2B of outer skin material Inner part 2C of outer skin material 3 Adhesive layer 4 Back surface nonwoven fabric layer 5 Outer skin Layer 6 Cushion layer 7 Intermediate nonwoven fabric layer 10 Mold 10A, 10B A pair of molds 10C Cavity N Resin injection nozzle DT Door trim (interior parts for automobile)

Claims (2)

It is a method for pasting a skin material of an automobile interior part, wherein a skin material is pasted to a resin core material with a thermoplastic adhesive,
The skin material before being bonded to the resin core material has an adhesive layer of the thermoplastic adhesive on the back surface thereof, and a back surface nonwoven fabric layer made of a nonwoven fabric as a skin material back surface outermost layer on the bottom surface of the adhesive layer,
The method of bonding the skin material to the resin core material is as follows:
Contacting the back surface nonwoven fabric layer side of the skin material with the resin core material; and
The thermoplastic adhesive of the adhesive layer is melted by the heat of the resin core material or the heat of the skin material or both of the heat from the contact and soaks into the back nonwoven fabric layer, and the soaked thermoplastic adhesive is the above-mentioned Adhesion stage in which the resin core material oozes out by the pressure applied to the skin material, and the resin adhesive and the back nonwoven fabric layer side of the skin material are pressure-bonded and bonded together by the squeezed thermoplastic adhesive. A method for pasting a skin material of an interior part for an automobile, characterized by comprising: The nonwoven surface material lamination method of automobile interior part according to claim 1, characterized in that the spun lace nonwoven fabric made by spun lace method.

Images