Multilayer panel, panel for vehicles and manufacturing method of multilayer panel

Abstract

To improve shock absorbability and inter-layer adhesiveness and stably realize a satisfactory strength even in a case where a metal plate includes a recess and metal plates are bolted with each other regarding a multilayer panel comprising the metal plates and a shock absorption member which is held between the metal plates.SOLUTION: A multilayer panel comprises at least two metal plates and a shock absorption member which is held between the metal plates. The metal plate includes a plurality of through holes for bolts. One metal plate includes a plurality of recesses for bolting which are recessed to the side of the other metal plate. The through hole for bolts is provided in the recess for bolting. The recess for bolting of the one metal plate is in contact with the other metal plate without interposing the shock absorption member therebetween, and is laminated and fixed by bolting. In a projection observation of the multilayer panel from an upper side, the shock absorption member is not present within a range WD which is twice the diameter D of the through hole.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laminated panel, a vehicle panel, and a method for manufacturing a laminated panel. [Background technology]

[0002] Various metal members are used as parts of transportation equipment such as automobiles, railway vehicles, ships, aircraft, etc. For example, an undercover for a vehicle is a plate-shaped member made of metal or synthetic resin, and is attached to the vehicle body using bolts and nuts.

[0003] Here, when used as an exterior part of an automobile such as an undercover, high strength and light weight are required. However, if the thickness of the metal component is increased in order to increase the strength, the mass of the component increases, and if the metal component is made thinner or the component is manufactured using a material such as plastic in order to reduce weight, there is a problem that sufficient strength cannot be ensured.

[0004] For this reason, various technologies have been developed for plate-like members used in automobiles and the like, so as to achieve both high strength and light weight. For this reason, for example, Patent Documents 1 and 2 disclose techniques for achieving both strength and weight reduction by sandwiching a foamed resin sheet between metal plates to form a sandwich panel. By using these techniques, it is possible to achieve both strength and weight reduction to a certain level. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4326001 [Patent Document 2] Patent No. 5703092 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the sandwich panels disclosed in Patent Documents 1 and 2 do not take into consideration the strength when the metal plate has large irregularities and the foamable resin sheet cannot be formed in some areas, and it was unclear whether a similarly high strength could be achieved in such cases. In addition, the sandwich panels disclosed in Patent Documents 1 and 2 do not take into consideration the impact absorption and interlayer adhesion of the laminate when some metal plates are fastened together by bolts without using a foamed resin sheet, and it is thought that providing stable strength for the panel is also an issue. The sandwich panels disclosed in Patent Documents 1 and 2 have a sandwich panel shape, and the tightening torque is large when fastening the bolts, so the foamed resin needs to be compressed while fastening, making it difficult to fix to parts. In addition, when a resin layer is used, there are issues such as bolt loosening due to vibration and bolt loosening caused by shrinkage of the resin layer due to temperature change, making it difficult to fasten the bolts to exterior parts of an automobile.

[0007] Therefore, the present invention aims to provide a laminated panel comprising metal plates and an impact absorbing member sandwiched between the metal plates, which has excellent impact absorption properties and interlayer adhesion, and achieves stable and excellent strength, even when the metal plates have recesses and the metal plates are fastened together with bolts. Another object of the present invention is to provide a manufacturing method for a laminated panel comprising metal plates and an impact absorbing member sandwiched between the metal plates, which is excellent in impact absorption properties and interlayer adhesion, and can achieve stable and excellent strength, even when the metal plates have recesses and the metal plates are fastened together with bolts. [Means for solving the problem]

[0008] The inventors have conducted extensive research into a laminated panel comprising at least two metal plates and an impact absorbing member sandwiched between the metal plates, and have discovered that by constructing a laminate such that, when the laminated panel is observed from above in a projected manner, there is no impact absorbing material around the through holes in the metal plates for bolt fastening, and more specifically, no impact absorbing member is present within a range twice the diameter of the through holes, it is possible to achieve excellent impact absorption properties and interlayer adhesion, as well as stable strength, even in cases where the metal plates have recesses and the metal plates are fastened together with bolts.

[0009] The present invention has been made based on the above findings, and the gist of the present invention is as follows. (1) A laminated panel having at least two metal plates and an impact absorbing member sandwiched between the metal plates, The metal plate has a plurality of bolt through holes, One metal plate has a plurality of bolt fastening recesses recessed toward the other metal plate, and the bolt through holes are provided in the bolt fastening recesses, the bolt fastening recess of the one metal plate is in contact with the other metal plate without the impact absorbing member therebetween, and the two metal plates are fixed to each other by fastening the bolts; A laminated panel, characterized in that, when the laminated panel is observed from above, the impact absorbing member is not present within a range twice the diameter of the through hole.

[0010] (2) The laminated panel according to (1), characterized in that the impact absorbing member is a foam.

[0011] (3) The laminated panel according to (1) or (2), further comprising a functional layer on the lamination surface side of the metal plate.

[0012] (4) The laminated panel according to any one of (1) to (3), wherein the length of the exposed portion of the impact absorbing member is 20% or less of the total outer periphery of the laminated panel.

[0013] (5) The laminated panel according to any one of (1) to (4), characterized in that, when the laminated panel is observed from above, the area ratio of the impact absorbing member to the area of ​​the metal plate is 30 to 90%.

[0014] (6) The laminated panel according to any one of (1) to (5), wherein the impact absorbing member has a compressive elastic modulus of 30 to 500 MPa and a 50% compressive stress of 3 to 20 MPa.

[0015] (7) A laminated panel according to any one of (1) to (6), characterized in that the impact absorbing member has a plurality of cutouts, and when the laminated panel is observed from above, the area ratio of the cutouts to the area of ​​the impact absorbing member is 5 to 60%.

[0016] (8) A vehicle panel, comprising the laminated panel according to (1) or (2).

[0017] (9) A vehicle panel as described in (8) above, characterized in that it is provided on a lower part of a vehicle.

[0018] (10) A method for manufacturing a laminated panel having at least two metal plates and an impact absorbing member sandwiched between the metal plates, a step of bonding the impact absorbing member in a sandwiched state between the metal plates; By subjecting one of the metal plates to bending processing, a plurality of bolt fastening members recessed toward the other metal plate side are formed. forming a recess for use; a step of bringing the bolt fastening recess of the one metal plate into contact with the other metal plate without the impact absorbing member therebetween, and fastening the two metal plates by bolts; A method for producing a laminated panel, comprising: Effect of the Invention

[0019] According to the present invention, a laminated panel having metal plates and an impact absorbing member sandwiched between the metal plates can achieve excellent impact absorption properties and interlayer adhesion, and can achieve stable and excellent strength, even in cases where the metal plates have recesses and the metal plates are fastened together with bolts. Furthermore, according to the present invention, there can be provided a manufacturing method for a laminated panel comprising metal plates and an impact absorbing member sandwiched between the metal plates, which manufacturing method is capable of realizing excellent impact absorption properties and interlayer adhesion and stable strength even when the metal plates have recesses and the metal plates are fastened together with bolts. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a diagram showing a schematic view of a portion of a cross section of the laminated panel of the present embodiment. [Diagram 2] FIG. 2 is an enlarged schematic view of a portion of a cross section of the laminated panel of the present embodiment. [Diagram 3] FIG. 2 is an enlarged schematic view of the upper surface of the laminated panel of the present embodiment. [Figure 4] 1 is a schematic diagram showing the impact absorbing member of the present embodiment as viewed from above; FIG. [Diagram 5] FIG. 1 is a schematic diagram showing a base for performing a bending test. [Figure 6] FIG. 1 is a diagram showing a schematic configuration for measuring a stress directly under a load generated during a bending test. [Figure 7] FIG. 2 is a diagram showing a schematic diagram of a laminated panel shape used in each of the examples and comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following embodiments are merely illustrative for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be modified appropriately within the scope of the gist thereof.

[0022] Fig. 1 is a schematic diagram of a part of a cross section of the laminated panel of this embodiment. Fig. 2 is a schematic diagram of an enlarged part of a cross section of the laminated panel of this embodiment. Fig. 3 is a schematic diagram of an enlarged top surface of the laminated panel of this embodiment.

[0023] <Laminated Panel> The laminated panel of this embodiment is a laminated panel 10 including at least two metal plates 11 and an impact absorbing member 12 sandwiched between the metal plates 11, as shown in FIG.

[0024] In the laminated panel 10 of this embodiment, as shown in FIG. 2, the metal plate 11 has a plurality of bolt through holes 11b. The bolt through hole 11b is a hole for passing a bolt 20 through. By passing a bolt through this bolt through hole 11b, the metal plates 11 are fastened together by the bolt, as shown in FIGS. 1 and 2.

[0025] The shape and size of the bolt through hole 11b are not particularly limited, and can be changed as appropriate depending on the performance required of the laminated panel 10 of this embodiment and the shape and size of the bolt 20. For example, the shape of the bolt through hole 11b may be circular (round hole). Also, depending on the shape and size of the bolt 20, the hole may be polygonal. Moreover, the size of the bolt through hole 11b is preferably larger than the diameter of the bolt 20. This is to prevent the laminated panel from being misaligned when fastening the laminated panel due to the influence of warping, deformation, etc. of the laminated panel, causing misalignment between the bolt through hole and the female mold of the fixing part, which makes it impossible to fasten the laminated panel.

[0026] Here, in the laminated panel 10 of this embodiment, as shown in Figure 1, one metal plate 11 (in Figure 1, the metal plate 11 provided on the top) has a plurality of bolt fastening recesses 11a recessed toward the other metal plate 11 (in Figure 1, the metal plate 11 provided on the bottom), and the bolt through holes 11b are provided within the bolt fastening recesses 11a, and the bolt fastening recesses 11a of the one metal plate 11 come into contact with the other metal plate 11 without the impact absorbing member 12 interposed therebetween, and the plates are stacked and fixed by bolt fastening. One of the metal plates 11 has the bolt fastening recess 11a, comes into contact with the other metal plate 11 without the impact absorbing member 12, and is stacked and fixed by bolt fastening, making it easier to fasten the metal plates 11 together with the bolts and improving the fastening force, thereby further improving the interlayer adhesion of the laminated panel.

[0027] In addition, in the one metal plate 11, the bolt through hole 11b is provided in the bolt fastening recess 11a, but the number of bolt through holes 11b provided in the bolt fastening recess 11a may be one or more and can be changed as appropriate. For example, when the size of the bolt fastening recess 11a is large, multiple bolt through holes 11b can be provided within the bolt fastening recess 11a, and when the size of the bolt fastening recess 11a is small, multiple bolt through holes 11b can be provided within one bolt fastening recess 11a.

[0028] In the laminated panel 10 of this embodiment, as shown in FIG. 1, when the laminated panel 10 is observed from above, the impact absorbing member 12 is not present within a range WD that is at least twice the diameter D of the through hole 11b. Although the impact absorbing member 12 such as a foamed resin sheet used in the laminated panel can increase the impact absorption properties of the laminated panel, it has been found that in the vicinity of the bolt through holes 11b in this embodiment, sufficient strength can be obtained by bolt fastening even without the formation of the impact absorbing member 12. On the other hand, it has been found that when the impact absorbing member 12 is present around the bolt through holes 11b, the thickness and elasticity of the impact absorbing member 12 hinder strong bolt fastening, deteriorating the impact absorption properties and interlayer adhesion, and becoming a factor in reducing the stability of strength. Furthermore, when the shock absorbing member is located directly below the bolt, the tightening torque of the bolt fastening part does not exert a tensile force due to the elasticity of the shock absorbing member, so the presence or absence of the bolt fastening part does not affect the bending rigidity. On the other hand, when there is no shock absorbing member at the bolt fastening part, the tensile force of the metal plate on one side contributes to the bending rigidity, so the bending rigidity can be improved while reducing the shock absorbing member. Therefore, in the laminated panel 10 of this embodiment, by not forming the shock absorbing member 12 within a range WD at least twice the diameter D of the through hole 11b, it is possible to suppress deterioration of shock absorbing properties and interlayer adhesion and obtain stable and excellent strength. In addition, the amount of the shock absorbing member 12 can be reduced, which is also effective from the viewpoint of weight reduction and manufacturing costs.

[0029] The diameter D of the through hole 11b refers to the maximum diameter D of the bolt through hole 11b when the laminated panel 10 of this embodiment is observed from above as shown in Fig. 2. For example, when the bolt through hole 11b is a round hole as shown in Fig. 2b, it is the diameter D of the bolt through hole 11b, and when the bolt through hole 11b is a polygonal hole, it is the length D of the diagonal line or the median line of the hole. In addition, the range WD twice the diameter D of the through hole 11b is a range in which the through hole 11b is uniformly expanded while having a diameter WD twice the diameter D of the through hole 11b, as shown in FIG. 2.

[0030] From the viewpoint of weight reduction and manufacturing cost reduction, the diameter D of the through hole 11b is set to 2.5. DoubleIt is preferable that the shock absorbing member 12 is not formed within the range of 3 times the diameter D of the through hole 11b. Double It is more preferable that the shock absorbing member 12 is not formed within this range. The upper limit of the range where the impact absorbing member 12 is not formed can be determined based on the impact absorbing properties and strength required for the laminated panel, and can be set appropriately so as not to deteriorate these properties.

[0031] The areas where the impact absorbing member 12 is not formed may be the same or different. For example, the area in which none of the shock absorbing members 12 are formed can be a range twice the diameter D of the through hole 11b, or a portion can be twice the diameter D of the through hole 11b, and a portion can be three times the diameter D of the through hole 11b.

[0032] Furthermore, in the laminated panel 10 of this embodiment, the length of the exposed portion of the impact absorbing member 12 relative to the total peripheral length of the laminated panel 10 is preferably 20% or less, more preferably 10% or less, even more preferably 5% or less, and particularly preferably 0% or less. Here, Fig. 3 is a schematic diagram showing the laminated panel 10 of this embodiment as viewed from above. If the ratio (A / X x 100%) of the length A of the exposed portion of the impact absorbing member 12 (the portion where the impact absorbing member 12 protrudes from the laminated panel 10 or where the impact absorbing member 12 can be observed on the outer periphery of the laminated panel 10 even if it does not protrude) to the total periphery length X of the laminated panel 10 is 20%, stable strength can be obtained without deteriorating the impact absorption and interlayer adhesion required for the laminated panel. In addition, from the viewpoint of preventing exposure to appearance, dirt, ultraviolet rays, and chemicals, it is preferable to suppress the exposure of the impact absorbing member 12 as much as possible.

[0033] (metal plate) Next, the laminated panel 10 of this embodiment includes a metal plate 11 as a constituent member. At least two metal plates 11 are required so as to sandwich the impact absorbing member 12. There is no particular limitation as long as there are two or more plates, and the number of plates can be appropriately increased depending on the required performance.

[0034] The material of the metal plate 11 is not particularly limited, and can be appropriately selected depending on the application of the laminated panel 10 and the required performance. For example, materials containing stainless steel, aluminum, copper, iron, etc. can be used as the material of the metal plate 11. These materials may be alloys, and from the viewpoint of improving corrosion resistance, etc., those that have been subjected to plating or coating treatment can be used. Furthermore, these metal plates 11 can also be commercially available metal plates.

[0035] The thickness of the metal plate 11 is not particularly limited, and can be appropriately selected depending on the application of the laminated panel 10 and the required performance. For example, from the viewpoint of a balance between weight reduction and strength, it is preferable that the average thickness of the metal plate 11 is about 1 mm.

[0036] (Foam) Moreover, the laminated panel 10 of this embodiment includes an impact absorbing member 12 sandwiched between the metal plates 11 . The shock absorbing member 12 can enhance the shock absorbing properties of the laminated panel 10 .

[0037] As described above, the shock absorbing member 12 is provided in a manner that avoids the periphery of the bolt through hole 11b of the metal plate 11. Specifically, when the laminated panel 10 is projected and observed from above, the area ratio (AS / MS×100%) of the shock absorbing member (AS) to the area (MS) of the metal plate 11 is preferably 30 to 95%. By providing the shock absorbing member 12 in these ranges, shock absorption and interlayer adhesion can be achieved at a high level, and more stable strength can be achieved. From the same viewpoint, when the laminated panel 10 is projected and observed from above, the area ratio (AS / MS×100%) of the shock absorbing member (AS) to the area (MS) of the metal plate 11 is more preferably 50 to 90%, and even more preferably 60 to 85%.

[0038] Furthermore, as shown in Figure 4, the impact absorbing member 12 has a plurality of cutout portions 12b, and when the laminated panel 10 is observed from above, the ratio (AHS / AS x 100%) of the area occupied by the cutout portions to the area (AS) of the impact absorbing member 12 is preferably 5 to 60%, more preferably 20 to 55%, and even more preferably 30 to 50%. The provision of the cutout portion 12b in the impact absorbing member 12 has the effect of reducing the weight of the laminate 10 and reducing manufacturing costs, and since the proportion of the area (AHS) occupied by the cutout portion (AHS / AS x 100%) is within the above range, it does not result in a decrease in impact absorption properties. The hollowed-out portion 12b means a portion of the impact absorbing member 12 that has been removed, and may be a through hole as shown in FIG. 4, or may be a hole that does not penetrate through, or may be formed by cutting out or thinning the area near the surface.

[0039] Furthermore, it is preferable that the impact absorbing member 12 has a plurality of lightening holes 12b as shown in FIG. 4, and when the impact absorbing member 12 has the lightening holes 12b, it is more preferable to increase the specific gravity of the impact absorbing member 12. For example, if an impact absorbing material with twice the specific gravity is used and a through hole is formed such that when the laminated panel 10 is observed from above, the ratio of the area of ​​the cutout portion (AHS) to the area of ​​the impact absorbing material 12 (AS) (AHS / AS x 100%) is 50%, better impact absorption performance can be obtained.

[0040] Furthermore, the impact absorbing member 12 preferably has a compressive elastic modulus of 30 to 500 MPa and a 50% compressive stress of 3 to 20 MPa. By increasing the compressive elastic modulus, the strength of the impact absorbing member 12 can be increased, and the compressive deformation during bending deformation can be suppressed, thereby maintaining high rigidity. If the 50% compressive stress is too high, the load when the impact absorbing member 12 comes into contact with a protective part after bending deformation becomes large, causing damage to the protective part. Therefore, by making the compressive elastic modulus and 50% compressive stress of the impact absorbing member 12 satisfy the above numerical ranges, the impact absorbing property can be further increased while the load applied to the protective part when the impact absorbing member 12 comes into contact with the protective part can be reduced. From the same viewpoint, the compressive elastic modulus of the impact absorbing member 12 is preferably 30 to 500 MPa, more preferably 50 to 300 MPa. The 50% compressive stress of the impact absorbing member 12 is preferably 3 to 20 MPa, more preferably 5 to 10 MPa.

[0041] The material of the impact absorbing member 12 is not particularly limited, and can be appropriately selected depending on the application of the laminated panel 10 and the required performance. The material for the shock absorbing member 12 may be, for example, a resin material, rubber, a foam, a spring, etc. Among these, from the viewpoint of obtaining better shock absorbing properties, it is preferable to use a foam, and it is more preferable to use a foam molded product such as a foam sheet or foam beads.

[0042] The foamed molded article may be made of, for example, a base resin, which may contain a thermoplastic resin, a thermosetting resin, a flame retardant, a rubber component, or the like. Examples of the thermoplastic resin include polyolefin resins such as polyethylene, polypropylene, and EVA (ethylene-vinyl acetate copolymer), polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, ABS (acrylonitrile-butadiene-styrene) resin, AS (acrylonitrile-styrene) resin, polystyrene resin, methacrylic resin, polyamide resin, polycarbonate resin, polyphenylene ether resin, polyimide resin, polyacetal resin, polyester resin, acrylic resin, cellulose resin, styrene-based, polyvinyl chloride-based, polyurethane-based, polyester-based, polyamide-based, 1,2-polybutadiene-based, and fluororubber-based thermoplastic elastomers, polyamide-based, polyacetal-based, polyester-based, and fluororubber-based thermoplastic engineering plastics, and powdered rubber. These may be used alone or in combination. Modified and crosslinked resins may also be used within the scope of the present invention. Examples of the thermosetting resin contained in the base resin include phenol-based resins, amino-based resins such as urea resins and melamine resins, unsaturated polyester-based resins, and epoxy-based resins. Among these, the base resin is preferably a thermoplastic resin containing a polyphenylene ether resin or a polycarbonate resin from the viewpoint of improving flame retardancy.

[0043] The polycarbonate resin is preferably a carbonate ester resin derived from bisphenols and phosgene (or diphenyl carbonate), and is characterized by having a high glass transition point and heat resistance. For example, polycarbonates derived from 2,2'-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2'-bis(4-hydroxyphenyl)butane (bisphenol B), 1,1'-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)methane (bisphenol F), 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)-1-phenylmethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,2-bis(4-hydroxyphenyl)ethane, etc. are suitable as such polycarbonate resins. These polycarbonates generally have a glass transition point (Tg) of 140 to 155°C.

[0044] Polycarbonate-based resins can be mixed with one or more other resins, and examples of such resins include polyethylene-based resins, polypropylene-based resins, acrylonitrile-butadiene-styrene copolymers (ABS resins), polystyrene-based resins, polyethylene terephthalate, polybutylene terephthalate, acrylonitrile-styrene copolymers (AS resins), syndiotactic polystyrene, polyphenylene oxide, polyacetal, polymethyl methacrylate, polyphenylene sulfide, polyethersulfone, polyarylate, polyamide, polyimide, and polyethylene naphthalate. When mixed with other resins, the content of the polycarbonate resin is preferably 50% by mass or more, and more preferably 70% by mass or more, from the viewpoint of flame retardancy.

[0045] In this specification, polyphenylene ether resin refers to a polymer represented by the following general formula (1). In this general formula (1), R1, R2, R3, and R4 each independently represent hydrogen, halogen, an alkyl group, an alkoxy group, a phenyl group, or a haloalkyl group or a haloalkoxy group having at least two carbon atoms between the halogen and the benzene ring in general formula (1) and not including the 3 α-carbon. Also, n is an integer representing the degree of polymerization.

[0046] [ka]

[0047] The polyphenylene ether resin preferably has a weight average molecular weight of 20,000 to 60,000.

[0048] Examples of polyphenylene ether resins include poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-methyl-6-propyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-ethyl-6-propyl-1,4-phenylene) ether, poly(2,6-dibutyl-1,4-phenylene) ether, poly(2,6-dilauryl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-diphenylene) ether, poly(2,6-dimethoxy ... ,4-phenylene) ether, poly(2,6-diethoxy-1,4-phenylene) ether, poly(2-methoxy-6-ethoxy-1,4-phenylene) ether, poly(2-ethyl-6-stearyloxy-1,4-phenylene) ether, poly(2,6-dichloro-1,4-phenylene) ether, poly(2-methyl-6-phenyl-1,4-phenylene) ether, poly(2,6-dibenzyl-1,4-phenylene) ether, poly(2-ethoxy-1,4-phenylene) ether, poly(2-chloro-1,4-phenylene) ether, poly(2,6-dibromo-1,4-phenylene) ether, etc. are included, but are not limited thereto. 1 and R 2 is an alkyl group having 1 to 4 carbon atoms, and R 3 and R 4 is preferably hydrogen or an alkyl group having a carbon number of 1 to 4. These may be used alone or in combination of two or more.

[0049] Among the above-mentioned thermoplastic resins, polyphenylene ether resins are more preferable because of their excellent flame retardancy and heat resistance. In particular, they can improve the deflection temperature under load (HDT), maintain rigidity even in a high-temperature environment, and provide good dimensional stability.

[0050] The polyphenylene ether resin can be mixed with one or more other resins, examples of which include polystyrene resins, polyolefin resins such as polypropylene, engineering plastic resins such as polyamide, super engineering plastic resins such as polyphenylene sulfide, etc. Among these, it is preferable to mix with a polystyrene resin from the viewpoint of improving processability.

[0051] In this specification, the term "polystyrene resin" refers to homopolymers of styrene and styrene derivatives, as well as copolymers mainly composed of styrene and styrene derivatives. Examples of styrene derivatives include, but are not limited to, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, α-methylstyrene, β-methylstyrene, diphenylethylene, chlorostyrene, and bromostyrene. Examples of the homopolymer polystyrene resin include polystyrene, polyα-methylstyrene, and polychlorostyrene. Examples of the copolymer polystyrene resin include styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, and the like. Examples of the copolymer include, but are not limited to, styrene-maleic anhydride copolymer, styrene-maleimide copolymer, styrene-N-phenylmaleimide copolymer, styrene-N-alkylmaleimide copolymer, styrene-N-alkyl substituted phenylmaleimide copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-n-alkyl acrylate copolymer, styrene-n-alkyl methacrylate copolymer, ethylvinylbenzene-divinylbenzene copolymer, as well as terpolymers such as ABS and butadiene-acrylonitrile-α-methylbenzene copolymer. Also included are graft copolymers, such as styrene-grafted polyethylene, styrene-grafted ethylene-vinyl acetate copolymer, (styrene-acrylic acid) grafted polyethylene, styrene-grafted polyamide, etc. These may be used alone or in combination of two or more.

[0052] The polystyrene resin preferably has a weight average molecular weight of 180,000 to 500,000. In this specification, the weight average molecular weight is the weight average molecular weight obtained by measuring the molecular weight of the peak of a chromatogram by gel permeation chromatography (GPC) using a calibration curve (created using the peak molecular weight of the standard polystyrene) obtained by measuring a commercially available standard polystyrene.

[0053] The content of the polystyrene resin in the base resin is not particularly limited, and is appropriately adjusted so that the other components are contained at the desired contents. On the other hand, the content of the polyphenylene ether resin in the base resin is preferably 40% by mass or more, more preferably 50% by mass or more, from the viewpoint of flame retardancy.

[0054] In order to achieve sufficient flame retardancy, it is preferable to further add a flame retardant to the base resin. Flame retardants include organic flame retardants and inorganic flame retardants, and organic flame retardants include halogen compounds such as bromine compounds and non-halogen compounds such as phosphorus compounds and silicone compounds, while inorganic flame retardants include metal hydroxides such as aluminum hydroxide and magnesium hydroxide, and antimony compounds such as antimony trioxide and antimony pentoxide.

[0055] Also usable may be various conventionally known flame retardants and flame retardant auxiliaries, for example, cyclic nitrogen compounds, specific examples of which include compounds having a triazine skeleton such as melamine, ammelide, ammeline, benzoguanamine, succinoguanamine, melamine cyanurate, melam, melem, meton, melon, and sulfates thereof, alkali metal hydroxides or alkaline earth metal hydroxides containing water of crystallization such as magnesium hydroxide and aluminum hydroxide, zinc borate compounds, zinc stannate compounds, etc. Also, not only one type but also a combination of two or more types may be used.

[0056] It is more preferable that the base resin contains a rubber component in order to improve foaming properties. Examples of rubber components include, but are not limited to, butadiene, isoprene, 1,3-pentadiene, etc. These are preferably dispersed in particulate form in a continuous phase made of a polystyrene-based resin. As a method for adding these rubber components, the rubber components themselves may be added, or resins such as styrene-based elastomers and styrene-butadiene copolymers may be used as a rubber component supply source.

[0057] In addition to the above, other thermoplastic resins, antioxidants, heat stabilizers, lubricants, pigments, dyes, weather resistance improvers, antistatic agents, impact resistance modifiers, glass molded bodies, inorganic fillers, nucleating agents such as talc, and the like may be added within a range that does not impair the object of the invention.

[0058] The foamed molded article is most preferably made of a base resin containing a polyphenylene ether resin, a polystyrene resin, a flame retardant, and a rubber component. In this case, the content of each component is preferably 40-94 mass% of the polyphenylene ether resin, 5-20 mass% of the flame retardant, and 0.3-10 mass% of the rubber component, with the remainder being the polystyrene resin.

[0059] If the polyphenylene ether resin content is 40% by mass or more, the heat resistance is excellent and the flame retardancy, particularly the performance of preventing resin dripping during combustion, is significantly improved. To prevent resin dripping during combustion, it is important to (1) shorten the burning time and (2) increase the heat resistance of the resin (make it less likely to soften), but simply increasing the amount of flame retardant added has the opposite effect to (2), so in order to prevent resin dripping in thinner samples, it is preferable to set the polyphenylene ether resin content to 40% by mass or more.

[0060] On the other hand, if the content of the polyphenylene ether resin exceeds 94% by mass, the temperature required for processing such as foaming and molding increases sharply, not only increasing utility costs but also requiring special equipment, resulting in a lack of practical productivity. The content of the polyphenylene ether resin in the base resin is more preferably 45 to 90 mass%, and even more preferably 50 to 85 mass%. By setting the content to 45 to 90 mass%, the foaming temperature and molding temperature become lower while maintaining heat resistance, and the process becomes easier.

[0061] The shape of the base resin is not particularly limited, but examples include beads, pellets, spheres, irregularly shaped pulverized products, etc. The size is preferably 0.2 to 5.0 mm, more preferably 0.2 to 3.0 mm. If the size is within this range, the beads after foaming will have an appropriate size, which makes them easy to handle, and also makes it easier to pack densely during molding.

[0062] The residual concentration of the aliphatic hydrocarbon gas remaining in the foamed molded product is preferably 1000 volume ppm or less. In this specification, the residual concentration of the aliphatic hydrocarbon gas is a value (volume ppm) obtained by dividing the volume of the aliphatic hydrocarbon gas contained in the foamed molded product by the volume of the foamed molded product, and 1 volume ppm (hereinafter simply referred to as "ppm") corresponds to 0.0001 volume%.

[0063] Examples of the aliphatic hydrocarbon gas include propane, n-butane, i-butane, n-pentane, i-pentane, and neopentane. If the residual concentration of the aliphatic hydrocarbon gas is 1000 ppm or less, the pilot flame will not smolder for a long time during combustion (called glowing). In combustion tests such as UL-94, the glowing time is specified in addition to the combustion time, and if the amount of the residual gas is small, it will be possible to clear the combustion test, especially the V-0 standard.

[0064] The foamed beads can be produced by any known method. For example, the foamed beads can be obtained by impregnating a base resin with a foaming agent (impregnation step) and foaming the base resin (foaming step).

[0065] (Functional layer) As shown in FIG. 1, the laminated panel 10 of this embodiment preferably further comprises a functional layer 13 on the lamination surface side of the metal plate 11, in addition to the above-mentioned metal plate 11 and impact absorbing member 12. Here, the functional layer 13 is a layer for mainly enhancing adhesion between the metal plate 11 and the impact absorbing member 12. By providing this functional layer 13 on the lamination surface side of the metal plate 11, that is, between the layers with the impact absorbing member 12 and at the interface between the metal plates 11, the interlayer adhesion can be strengthened, and the laminated panel 10 can achieve more stable and excellent strength. In addition, the functional layer 13 also has the effect of filling the gaps between layers to prevent the intrusion of impurities such as water.

[0066] The functional layer 13 is not particularly limited as long as it can increase the adhesion between the metal plate 11 and the impact absorbing member 12 . Examples of the adhesive include adhesives, coating agents, paint materials, films, sheets, tapes, and nonwoven fabrics.

[0067] Furthermore, the thickness of the functional layer 13 is not particularly limited, and can be appropriately determined from the viewpoint of the balance between the weight reduction and manufacturing cost of the laminated panel 10 and the improvement of interlayer adhesion.

[0068] The functional layer 13 can be formed on only one surface of the metal plate 11, or on both surfaces of the functional layer. Furthermore, the functional layer can be formed on the entire surface of the lamination surface of the metal plate 11, or can be formed only on an arbitrary portion within the surface.

[0069] In addition to the metal plate 11, the impact absorbing member 12, and the functional layer 13 described above, the laminated panel 10 of the present embodiment can include any known member appropriate for the intended use of the laminated panel.

[0070] <Laminated Panel Manufacturing Method> Next, a method for manufacturing the laminated panel of this embodiment will be described. The manufacturing method of the laminated panel of this embodiment is as shown in FIG. A manufacturing method of a laminated panel 10 having at least two metal plates 11 and an impact absorbing member 12 sandwiched between the metal plates, a step of bonding the shock absorbing member 12 in a sandwiched state between the metal plates 11; a step of forming a plurality of bolt fastening recesses 11a recessed toward the other metal plate 11 by bending one of the metal plates 11; a step of bringing the bolt fastening recess 11a of the one metal plate into contact with the other metal plate 11 without the impact absorbing member 12 therebetween, and fastening the two metal plates by bolts; Includes. By going through the above steps, the laminated panel of the present embodiment described above can be obtained. The configuration of the laminated panel 10 is as described above.

[0071] In addition, in the manufacturing method of the laminated panel of this embodiment, the impact absorbing member 12 is sandwiched between the metal plates 11 and bonded, and then one of the metal plates 11 is bent to form a plurality of bolt fastening recesses 11a recessed toward the other metal plate 11. This makes it possible to form the bolt fastening recesses 11a while sandwiching the shock absorbing member 12 between the metal plates 11.

[0072] The method for bonding the impact absorbing member 12 between the metal plates 11 while sandwiching the impact absorbing member 12 is not particularly limited. For example, there are methods such as imparting adhesiveness to the impact absorbing member 12, providing a functional layer 13 between the metal plate 11 and the impact absorbing member 12, and using a hot melt film as a functional layer and bonding by thermal welding.

[0073] <Vehicle panels> The vehicle panel of this embodiment is formed using the laminated panel of this embodiment described above. As a result, the vehicle panel of this embodiment has an uneven shape and is excellent in impact absorption and interlayer adhesion, and can achieve stable, excellent strength, even in a configuration in which the metal plates are fastened together with bolts.

[0074] Here, the type of the vehicle panel is not particularly limited, and may be used as, for example, a lower panel, a side panel, or an upper panel of a vehicle. More specifically, examples of the components include cover-shaped components of a vehicle, such as an undercover, a door panel, a roof panel, an oil pan, etc. Among these, use as an undercover is preferred in that the effects of the vehicle panel of the present embodiment can be more effectively enjoyed. EXAMPLES

[0075] The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

[0076] <Examples 1 to 17 and Comparative Examples 5 to 9> Under the conditions shown in Table 1, a sample of a laminated panel including two metal plates and an impact absorbing member sandwiched between the metal plates was produced. The shape of the laminated panel was as shown in Tables 1 and 2 and FIG.

[0077] <Comparative Examples 1 to 4> Under the conditions shown in Tables 1 and 2, a sample of a laminated panel made of two metal plates was produced. The shape of the laminated panel was as shown in Table 2 and FIG.

[0078] <Evaluation> The following evaluations were carried out for each sample of the prepared laminated panel. The evaluation results are shown in Tables 1 and 2.

[0079] (1) Load at 10mm displacement For each sample, the load (N) was measured using a Shimadzu Corporation UH-500kNIR in the configuration shown in the table and the arrangement shown in Figure 5. The indenter descending speed was 10 mm / min, and the indenter shape was a hemispherical φ100 mm.

[0080] (2) EA at 10mm displacement For each sample, a load-displacement curve was obtained using a Shimadzu Corporation UH-500kNIR in the configuration shown in the table and the arrangement shown in Figure 5. The indenter speed was 10 mm / min. The area of ​​the load-displacement curve at a displacement of 10 mm was taken as the energy absorption amount, and the energy absorption amount: EA (J) was measured.

[0081] (3) Stress directly below the load For each sample prepared, a load-displacement curve was obtained using a Shimadzu Corporation UH-500kNIR in the configuration shown in the table and the arrangement shown in Figure 5. A small compression load cell LMC-A-20kN (Kyowa Electric Industry Co., Ltd.) and the steel plate were arranged at a displacement of 10 mm directly below the indenter as shown in Figure 6, and the test was carried out until the shock absorbing material was compressed 1 mm after contact, and the load at that time was read. The stress (MPa) directly below the load was measured by dividing the load at the time of compression 1 mm after contact by the area of ​​the steel plate.

[0082] (4) Bolt fixing For each sample, the bolts were tightened by hand, and when the load increased, a torque wrench was used to tighten them. If the number of bolt rotations after switching to the torque wrench exceeded 10kN in 5 rotations or less, it was marked as "Good", and if the number of bolt rotations did not exceed 10kN even after 10 rotations, it was marked as "Poor".

[0083] [Table 1] [Table 2]

[0084] *1 The resin types are as follows: PPE-based: Asahi Kasei Corporation's "Sunforce (registered trademark) BE", PE-based: Asahi Kasei Corporation's "Mef (registered trademark)", PA-based: beads produced using the same method as in Patent No. 7058315, PUR-based: Inoac Corporation's "Calmflex (registered trademark) F140" The PPE, PE, and PA beads were molded to have the densities shown in Tables 1 and 2, and foamed molded articles of the specified sizes were produced. *2, *3 Thickness (mm), density (g / cm 3 ), areal density (kg / m 2 ) was calculated as follows: After measuring the mass W (g) of the shock absorbing material, the area S (m 2 ), volume V(cm 3 ) and W / S (kg / m 2 ) is the surface density of the bead foam molding, and W / V (g / cm 3 ) was taken as the density of the bead foam molding. *4 The closed cell ratio of the impact absorbing material was measured by cutting out a rectangular parallelepiped sample of impact absorbing material measuring 20 mm in length, 20 mm in width, and the thickness (mm) shown in Table 1 from the impact absorbing material. S(%)={(Vx-W / ρ) / (Va-W / ρ)}×100 ···(1) In formula (1), Vx is the true volume of the foam (cm 3 ) and Va is the apparent volume of the foam (cm 3 ), W is the weight of the foam (g), and ρ is the density of the base resin of the foam. degree(g / cm 3 The true volume of the foam is calculated using a pycnometer. *5 The compressive elastic modulus and 50% compressive stress of the impact absorbing material were measured in accordance with JIS K 7220 (2006). *6 The area ratio of the through holes (lightening parts) of the impact absorbing material was calculated by calculating the ratio of the total area of ​​the through holes of the impact absorbing material to the area of ​​the impact absorbing material when the laminated panel is projected from above. *7 The average thickness of the impact absorbing material is the average thickness of the entire impact absorbing material. *8 The resin types are as follows: Urethane-based: SikaForce (registered trademark)-7750 L80MR (A) and SikaForce (registered trademark)-7750 (B) two-part mixture manufactured by Sika Japan Co., Ltd. Double-sided tape: 3M Japan Co., Ltd. "Acrylic foam tape (product number: GT7102)" *9 The shapes are as follows: Two-part mixture: The urethane adhesive was prepared by mixing SikaForce®-7750 L80 MR (A) and SikaForce®-7750 (B) in a weight ratio of 1:1, and then applied to the metal plate to laminate and bond the shock-absorbing material. Double-sided tape: Double-sided tape was applied to the entire contact surface between the metal plate and the shock absorbing member, and the metal plate and the shock absorbing member were laminated and bonded together. *10 The density of the functional layer was calculated by measuring the weight of the adhesive and double-sided tape used in advance, calculating the difference in thickness between the metal plate and the impact absorbing material from the total thickness after lamination, and calculating the volume using the applied area. The density of the functional layer was then calculated from this ratio. *11 The average thickness of the functional layer is the overall average thickness of the functional layer. *12 The adhesive parts of the functional layer are as follows: Both sides: Functional layers are provided on both sides of the impact absorbing material. One side (top): Functional layers are provided only on the top side of the impact absorbing material. One side (bottom): Functional layers are provided only on the bottom side of the impact absorbing material. *13 The surface density of the functional layer is calculated by measuring the mass W (g) and then measuring the area S (m 2 ) and W / S (kg / m 2 ) was defined as the areal density of the functional layer. *14 The curing time for the functional layer was 48 hours or more. *15 The hardening load for the functional layer was 0.2 MPa. *16 The types of metal upper and lower plates are as follows: AL: Aluminum, SPCC: Cold rolled steel plate, *17 The thickness of the upper metal plate and the lower metal plate is the average thickness of the whole. *18 The bending elastic modulus of the upper metal plate and the lower metal plate was measured in accordance with JIS K 7171. *19 The surface density of the upper and lower metal plates is calculated by measuring the mass W (g) and then measuring the area S (m 2 ) and W / S (kg / m 2 ) was defined as the areal density of the upper metal plate and the lower metal plate. *20 The shapes A and B of the laminated panels are as shown in Figure 7.

[0085] From the results in Table 1, it can be seen that each sample of the laminated panel of the embodiment has a well-balanced excellent performance and can obtain a stable high strength. On the other hand, the sample of the comparative example was inferior to the practical sample in any performance. [Industrial Applicability]

[0086] According to the present invention, a laminated panel having metal plates and an impact absorbing member sandwiched between the metal plates can achieve excellent impact absorption properties and interlayer adhesion, and can achieve stable and excellent strength, even in cases where the metal plates have recesses and the metal plates are fastened together with bolts. Further, according to the present invention, there is provided a method for manufacturing a laminated panel including metal plates and an impact absorbing member sandwiched between the metal plates, which is excellent in impact absorption properties and interlayer adhesion and can stably achieve excellent strength even when the metal plates have recesses and the metal plates are fastened to each other by bolts. can provide the law.

Claims

1. A laminated panel comprising at least two metal plates and an impact absorbing member sandwiched between the metal plates, The metal plate has a plurality of bolt through holes, One metal plate has a plurality of bolt fastening recesses recessed toward the other metal plate, and the bolt through holes are provided in the bolt fastening recesses, the bolt fastening recess of the one metal plate is in contact with the other metal plate without the impact absorbing member therebetween, and the two metal plates are fixed to each other by fastening the bolts; A laminated panel, characterized in that, when the laminated panel is observed from above, the impact absorbing member is not present within a range twice the diameter of the through hole.

2. The laminated panel according to claim 1 , wherein the shock absorbing member is a foam.

3. The laminated panel according to claim 1 or 2, further comprising a functional layer on the lamination surface side of the metal plate.

4. 3. The laminated panel according to claim 1, wherein a length of the exposed portion of the impact absorbing member is 20% or less of a total peripheral length of the laminated panel.

5. The laminated panel according to claim 1 or 2, characterized in that, when the laminated panel is observed from above, the area ratio of the impact absorbing member to the area of ​​the metal plate is 30 to 90%.

6. The laminated panel according to claim 1 or 2, wherein the impact absorbing member has a compressive elastic modulus of 30 to 500 MPa and a 50% compressive stress of 3 to 20 MPa.

7. The impact absorbing member has a plurality of lightening portions, and when the laminated panel is projected and observed from above, the area ratio of the lightening portions to the area of ​​the impact absorbing member is 5 to 60%. The laminated panel according to claim 1 or 2.

8. A vehicle panel comprising the laminated panel according to claim 1 or 2.

9. The vehicle panel according to claim 8, which is provided in a lower portion of a vehicle.

10. A method for manufacturing a laminated panel having at least two metal plates and an impact absorbing member sandwiched between the metal plates, a step of bonding the impact absorbing member in a sandwiched state between the metal plates; a step of bending one of the metal plates to form a plurality of bolt fastening recesses recessed toward the other metal plate; a step of bringing the bolt fastening recess of the one metal plate into contact with the other metal plate without the impact absorbing member therebetween, and fastening the two metal plates by bolt fastening; A method for producing a laminated panel, comprising:

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