Polymer foam laminated structure

Abstract

The present invention relates to a polymer foam laminate structure (1), which comprises: - a first solid layer (101) covered by at least one first functional layer (103) and having a density greater than 1000 g / l; - a polymer foam layer (105) provided on said at least one first functional layer (103); a second solid layer (109) having a density greater than 1000 g / l and covered by at least one second functional layer (107), said at least one second functional layer (107) being in contact with said polymer foam layer (103); Including, The polymer foam layer (105) has a density of 20 g / l to less than 1000 g / l. The present invention further relates to a method for preparing a polymeric foam laminate structure (1) and, inter alia, a composite component (1000) comprising the polymeric foam laminate structure (1).

Description

Technical Field

[0001] The present invention relates to a polymer foam laminate and a method for preparing the same. The present invention further relates to a polymer foam laminate and, in particular, to the use of a composite component comprising a polymer foam laminate according to the present invention.

Background Art

[0002] Today, the requirements for engineering materials, such as those in the aerospace, automotive, and marine industries, are directed towards materials that are lightweight while ensuring rigidity, stability, and strength. In particular, in the application of energy-absorbing materials, high-density thermoplastic foams can exhibit high energy absorption to ensure dynamic impact tests.

[0003] Generally, the use of such foams is known from the prior art, such as DE102018111510A1, where an energy-absorbing device having a tubular element filled with a first type of pellet and a second type of pellet is disclosed, and the first type of pellet is deformable with respect to the second type of pellet. For the first type of pellet, a foamed material such as polystyrene can be used, and the harder second type of pellet can be made of polyvinyl chloride. Energy absorption takes place inside the tubular container.

[0004] Another prior art, EP3272798A1, generally relates to a polyamide resin foam molded product and a method for manufacturing the same. Such articles are described as being suitable for insulating materials and automotive components such as engines, or cylinder head covers, body structures, and electrical equipment cases.

[0005] US5,746,537 describes a polymer closed-cell foam as a collision-absorbing element for automobiles. Thermoplastic foams such as PVC, PU, and PS are described. Adhesion to a metal surface is not described.

[0006] However, when thermoplastic foam materials are used for energy absorption components, prior art does not provide a satisfactory solution for bonding the foam to known structural materials such as steel, aluminum, or reinforced plastics. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] DE102018111510A1 [Patent Document 2] EP3272798A1 [Patent Document 3] US5,746,537 [Overview of the project] [Problems that the invention aims to solve]

[0008] Therefore, the fundamental objective of the present invention is to provide a novel polymer foam laminated structure that overcomes the shortcomings of the prior art and, in particular, provides sufficient bonding between the polymer foam material and the solid structural material. Another objective of the present invention is to provide a method for preparing such a polymer foam laminated structure. [Means for solving the problem]

[0009] The above-mentioned problems are solved by the polymer foam laminated structure (1) according to the first aspect of the present invention, and the polymer foam laminated structure (1) is - A first solid layer (101) covered by at least one first functional layer (103) and having a density greater than 1000 g / l, - A polymer foam layer (105) provided on at least one first functional layer (103), - A second solid layer (109) covered by at least one second functional layer (107) and having a density exceeding 1000 g / l, wherein the at least one second functional layer (107) is in contact with the polymer foam layer (103), Includes, The polymer foam layer (105) has a density of 20 g / l to less than 1000 g / l.

[0010] Furthermore, the above-mentioned problems are solved in a second embodiment of the present invention, particularly by a method for preparing a polymer foam laminated structure (1) according to any one of claims 1 to 12, the method comprising the following steps: a1) A step of providing a first solid layer (101), a2) The step of providing a second solid layer (101), b1) Providing at least one first functional layer (103) on the first solid layer (101), b2) Providing at least one second functional layer (107) on the second solid layer (109), c) Providing a polymer foam layer (105) on top of the at least one first functional layer (103) and below the at least one second functional layer (107), It has, thereby obtaining a pre-laminated structure, d) The step of pressing the pre-laminated structure at the raised temperature, e) A step of obtaining a polymer foam laminated structure (1), It holds.

[0011] According to the present invention, known hard constituent materials such as steel, aluminum, or reinforced plastic can be thermally bonded with a polymer foam layer to obtain a novel constituent material. The polymer foam laminated structure (1) according to the present invention can be applied, for example, as an energy absorbing member of an impact element.

[0012] When polyamide is used as the polymer foam layer (105), the polymer foam laminated structure (1) of the present invention can withstand high temperatures (e.g., 190°C in the curing oven) during cathode dip coating. On the other hand, a rigid layer (e.g., the first solid layer (101), e.g., metal) agglomerated and connected to the rigid and tough polymer foam (i.e., the polymer foam layer (105)) by at least one first functional layer (103) and a sandwich portion (i.e., the polymer foam laminated structure (1)) having excellent impact absorption performance could be obtained. As shown in the examples below, delamination or damage between the layers of the sandwich (i.e., the polymer foam laminated structure (1)) does not occur during the impact test or bending test.

Brief Description of the Drawings

[0013] [Figure 1] Figure 1 is a schematic view of the polymer foam laminated structure 1 according to an embodiment of the present invention. [Figure 2] Figure 2 is a photograph of examples and comparative examples related to the polymer foam laminated structure 1. [Figure 3] Figure 3 is a graph of the force-displacement curves of the examples and comparative examples in Figure 2. [Figure 4] Figure 4 is a graph of the absorbed energy of the examples and comparative examples in Figure 2. [Figure 5] Figure 5a is a graph of the force-displacement curve of the test piece "PA particle foam 13", and Figure 5b is a photograph of the test piece based on the graph in Figure 5a. [Figure 6] Figure 6a is a graph of the force-displacement curve of the test piece "TPU foam", and Figure 6b is a photograph of the test piece based on the graph in Figure 6a. [Figure 7] Figure 7 is a photograph of the test device with the test piece according to the present invention inserted. [Figure 8] Figure 8 is a graph comparing bending actions.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, the present invention will be described in detail.

[0015] In the following description of the polymer foam laminated structure (1) according to the present invention, when features are mentioned, they also refer to the methods according to the present invention as described herein. Similarly, features mentioned in the description of the methods according to the present invention also extend to the polymer foam laminated structure (1) according to the present invention.

[0016] In a first aspect, the present invention relates to a polymer foam laminated structure (1), wherein the polymer foam laminated structure (1) is - A first solid layer (101) covered by at least one first functional layer (103) and having a density greater than 1000 g / l, - A polymer foam layer (105) provided on the at least one first functional layer (103), - A second solid layer (109) covered by at least one second functional layer (107) and having a density exceeding 1000 g / l, wherein the at least one second functional layer (107) is in contact with the polymer foam layer (103), Includes, The polymer foam layer (105) has a density of 20 g / l to less than 1000 g / l.

[0017] As used herein, the term “solid layer” should be understood in the sense of the present invention to mean that this particular layer(s) is made of a solid material that is essentially non-porous, in contrast to the term “polymer foam layer” which exhibits significant porosity. To draw a clear line between the two terms, a density of around 1000 g / l is given.

[0018] The density of the polymer foam layer (105) is determined according to DIN EN ISO 845-10:2009, and the densities of the first and second functional layers (103, 107) are determined according to DIN EN ISO 1183.

[0019] To enhance the bonding between the first solid layer (101) and the polymer foam layer (105), at least one first functional layer (103) covers the first solid layer (101) and functions in particular as an adhesive layer. Similarly, the second solid layer (109) is covered by at least one second functional layer (107) that is in contact with the polymer foam layer (103).

[0020] According to the present invention, the first and second functional layers (103, 107) are tools for obtaining a force-lock connection between the first and second solid layers (101, 109) and the polymer foam layer (105).

[0021] In particular, the first and second functional layers (103, 107) contain an unreinforced polymer, which, due to its chemical structure (polyamide), is particularly suitable for providing good adhesion to the surfaces of the first and second solid layers (101, 109). Because the first and second functional layers (103, 107) are highly elastic, the tension between the polymer foam layer (105) and the first and second solid layers (101, 109) during formation or bending can be offset. Furthermore, stress arising from the different thermal expansion coefficients of the first and second solid layers (101, 109) and the polymer foam layer (103) can be absorbed.

[0022] The present invention offers the advantageous effect that well-known rigid structural materials as first and second solid layers (101, 109) (such as steel, aluminum, or reinforced plastic) can be thermally bonded with a polymer foam layer (103) to produce a novel structural material, namely the polymer foam laminated structure (1) of the present invention.

[0023] A further advantage is the use of lightweight materials, which involves the integration of metal into the vehicle body. The metal (e.g., for the solid layers (101, 109)) is covered with the first and second functional layers (103, 107) and then processed using standard steelworking techniques such as deep drawing. The particulate foam for the polymer foam layer (105) can be directly processed onto the first and second functional layers (103, 107) using hot steam in a mold (lamination and fusion of pre-foamed particles in one step). Alternatively, the particulate foam portion for the polymer foam layer (105) is thermally laminated onto the first and second functional layers (103, 107).

[0024] For example, in contrast to US5,746,537, the present invention enables the combination of a rigid polymer foam with a metal body, which can further withstand high temperatures that may occur, for example, during cathode drip coating.

[0025] In a particular embodiment of the polymer foam laminated structure (1) of the present invention, the polymer foam is obtained by welding prefoamed thermoplastic particles with steam, IR irradiation, or microwave. The prefoamed thermoplastic particles are thermoplastic polyurethane (TPU) (especially BASF SE's "Infinergy 100 HD"), or polyamide (PA6, PA12, PA6.12, PA6.12, PA6 / 6.36, polyether block copolyamide, PA66, PA6T / 66, PA6I / 6T, PA6T / 6I, PA9T, TPU and mixtures thereof (especially BASF SE's copolyamide PA6 / 6.36 "Ultramid® Flex F38" and blends of PA6 / 6.36 and polyamide 6, density 1060 kg / m³) 3 ~1090 kg / m 3 It contains a relative viscosity (RV) of 3.7-3.9 and a melting point of 199°C.

[0026] Further developments of the polymer foam laminated structure (1) of the present invention include first and second functional layers (103, 107) which are thermoplastic layers comprising polyamide, thermoplastic polyurethane, hot melt, or a combination thereof.

[0027] The first and second functional layers (103, 107) are preferably thermoplastic and compatible with the surfaces of the first and second solid layers (101, 109). They have a melting or softening point of less than 250°C. The materials used are preferably polyamides (particularly PA6, PA6 / 6.36, PA6 / 66, PA12, PA6.12, PA6.10, PA6I / 6T, caprolactam or lauryl lactam copolymers), thermoplastic polyurethanes (TPUs), hot melts, and polyether block copolyamides.

[0028] As used herein, the term "hot melt" should be understood to refer to solvent-free or anhydrous products that are more or less solid at room temperature, exist as viscous liquids at high temperatures, and are applied to bonding surfaces. Upon cooling, they reversibly solidify, forming a strong bond. This group of adhesives consists of thermoplastic polymers based on various chemical raw materials. The main polymers used in these physically solidifying hot melt adhesives are polyamide resins, saturated polyesters, ethylene vinyl acetate (EVA) copolymers, polyolefins, block copolymers (styrene-butadiene-styrene or styrene-isoprene-styrene), and polyimides. Polyamides, polyesters, and polyimides are used in so-called high-performance hot melt adhesives, while ethylene-vinyl acetate copolymers and polyolefins are used in so-called mass melt adhesives.

[0029] The first and second functional layers (103, 107) may also contain other functional additives such as plasticizers, or functional polymers such as maleic anhydride graft copolymer of polyethylene and α-polyolefin or MA graft copolymer of polyethylene and acrylic acid ester.

[0030] According to the present invention, it may be useful to increase the toughness and elasticity of the functional layer using the above-mentioned additives so that it is better formed in the polymer foam laminated structure (1) and less susceptible to damage.

[0031] In a further development of the present invention, the polymer foam layer (105) has a softening point of 100°C to 280°C.

[0032] The term "softening point" in the case of semicrystalline polymers refers to the melting temperature Tm, which can be determined by differential scanning calorimetry (DSC) according to DIN EN ISO 11357-3:2014.

[0033] On the other hand, the term "softening point" in the case of amorphous polymers refers to the glass transition temperature Tg, which can be determined by differential scanning calorimetry (DSC) at a heating rate of 20 K / min according to DIN EN ISO11357-2:2014.

[0034] According to the present invention, preferably the polymer foam layer (105) is - Melting pre-foamed polymer particles, or - Extruding a thermoplastic polymer through a slot die in the presence of a foaming agent, or - Filling a thermoplastic polymer with a foaming agent at a temperature exceeding its softening temperature in an autoclave, followed by expansion and molding, - Using a foam injection molding machine, - In a special mold, pre-foamed polymer particles are directly fused onto the first and second functional layers (103, 107) using steam. It can be obtained by this.

[0035] The "fusion" methods include steam chest molding, steamless molding techniques, bonding and / or joining techniques such as Atecarma® technology (of Teubert Maschinenbau GmbH).

[0036] In certain embodiments, the polymer foam of the polymer foam layer (105) may be open-cell or closed-cell.

[0037] The polymer foam laminated structure (1) of the present invention is preferable when the polymer foam layer (105) contains polyamide, thermoplastic polyurethane, polyether block copolyamide, polypropylene, polystyrene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester / polylactide (PLA), polyethersulfone (PESU), and mixtures thereof.

[0038] Polyamides offer a favorable combination of high rigidity, toughness, and thermal stability.

[0039] Furthermore, the polymer foam laminated structure (1) of the present invention is preferable if at least one first functional layer (103) and / or at least one second functional layer (107) comprises polyamide, particularly PA6, PA6 / 6.36; PA12, PA610, PA6 / 66, PA6.12, and polyether block copolyamide.

[0040] Polyamide exhibits advantageous adhesion behavior to metal surfaces primed with acrylate.

[0041] In the polymer foam laminated structure (1) of the present invention, at least one first functional layer (103) and / or at least one second functional layer (107) may further comprise a homopolymer or copolymer of ethylene and / or α-olefin and / or acrylic acid ester and / or maleic anhydride.

[0042] The homopolymer or copolymer acts as an impact resistance modifier for the first and second functional layers (103, 107), increasing the elongation at break so that the metal portion (i.e., the solid layer (101, 109)) to which the first and second functional layers (103, 107) are already laminated can be processed by deep drawing techniques without damaging the first and second functional layers (103, 107).

[0043] In particular, homopolymers or copolymers can be grafted with maleic anhydride.

[0044] Grafting with maleic anhydride improves the compatibility between homopolymers or copolymers and polyamides.

[0045] To ensure sufficient bonding of the polymer foam laminated structure (1) of the present invention, at least one first functional layer (103) and / or at least one second functional layer (107) have a thickness between 20 μm and 2000 μm.

[0046] This thickness can be measured with an ultrasonic slide gauge.

[0047] The functional layer needs to have a certain thickness (typically 400 μm to 1000 μm) to ensure that the spaces on the uneven surface of the particulate foam portion (i.e., polymer foam layer (105)) are filled with the polymers of the first and second functional layers (103, 107). On the other hand, if the polymer foam of the polymer foam layer (105) has a smooth surface (like foam from die extrusion), the thickness of the first and second functional layers (103, 107) can be reduced.

[0048] The first and second functional layers (103, 107) can each be manufactured using standard thermoplastic product technology (calendering), and then laminated onto the first and second solid layers (101, 109), respectively, by, for example, a coil coating line or hot press, interval hot press or double belt press.

[0049] In a first alternative embodiment of the present invention, the first solid layer (101) and / or the second solid layer (109) are preferably metal layers having a thickness between 150 μm and 2000 μm. This is a typical thickness metal roll product.

[0050] In a second alternative embodiment of the present invention, the first solid layer (101) and / or the second solid layer (109) are preferably solid polymer layers having a thickness between 1 mm and 10 mm. There are typical thicknesses that can be achieved by injection molding.

[0051] According to a second alternative embodiment of the polymer foam laminated structure (1) of the present invention, the solid polymer layer as the first solid layer (101) and / or the second solid layer (109) comprises a polymer material reinforced with carbon fibers, glass fibers, aramid fibers, basalt fibers, natural fibers, metal fibers, potassium titanate particles and mixtures thereof.

[0052] In particular, reinforcing fibers can be incorporated as roving or cut continuous fibers in their usual commercial form. Furthermore, woven fabrics, scrims, floats, mats, and staple fibers made from the above-mentioned reinforcing materials can also be used.

[0053] From the viewpoint of mechanical stability, it is particularly preferable that the polymer foam laminated structure (1) of the present invention has a first solid layer (101) in force-lock contact with at least one first functional layer (103) and a second solid layer (109) in force-lock contact with at least one second functional layer (107).

[0054] The above problems are solved in a second embodiment of the present invention by a method for preparing a polymer foam laminated structure (1) as described above, the method comprising the following steps a1) A step of providing a first solid layer (101), a2) The step of providing a second solid layer (101), b1) Providing at least one first functional layer (103) on the first solid layer (101), b2) Providing at least one second functional layer (107) on the second solid layer (109), c) Providing a polymer foam layer (105) on top of the at least one first functional layer (103) and below the at least one second functional layer (107), It has, thereby obtaining a pre-laminated structure, d) The step of pressing the pre-laminated structure at the raised temperature, e) A step of obtaining a polymer foam laminated structure (1), It is obtained by a method that includes the following.

[0055] The method of the invention according to the present invention has, in principle, the same advantageous effects as those given above for the polymer foam laminated structure (1) of the present invention. Rigid structural materials, well known as first and second solid layers (101, 109), can be thermally bonded with a polymer foam layer (103) to obtain a novel structural material. For this production, general equipment can be used and appropriate preparation conditions can be applied.

[0056] This method for preparing a polymer foam laminated structure (1) involves the following steps in a very specific embodiment. a1) A step of providing a first solid layer (101), b1) Providing at least one first functional layer (103) on the first solid layer (101), c1) A step of providing pre-foamed thermoplastic beads of polymer foam material for a polymer foam layer (105), wherein the thermoplastic beads have a raw material density of 200 g / l to 400 g / l, d1) A step of providing a polymer foam layer (105) by directly fusing the pre-foamed beads onto the at least one first functional layer (103) with hot steam or heat irradiation (IR), e) A step of obtaining a polymer foam laminated structure (1), It can be modified by including it.

[0057] The method of the present invention will be described in more detail when referring to specific embodiments.

[0058] Another aspect of the present invention relates to the use of the polymer foam laminated structure (1) of the present invention, as detailed above, as an energy absorption device.

[0059] As shown by the examples and comparative examples of the present invention, the polymer foam laminated structure (1) of the present invention is particularly applicable as an energy absorption device when provided, for example, on an impact element.

[0060] Finally, a very specific aspect of the present invention refers to a composite component (1000), the composite component (1000) is, - The polymer foam laminated structure (1) described in detail above according to the present invention, - At least one polymer layer (1003) provided on either the first solid layer (101) or the second solid layer (109) of the polymer foam laminated structure (1), - A metal layer (1001) provided on the at least one polymer layer (1003) on the opposite side of the polymer foam laminated structure (1) according to any one of claims 1 to 12, Includes, The at least one polymer layer (1003) comprises an expandable material.

[0061] In other words, the polymer foam laminated structure (1) of the present invention is given additional functions, namely flame retardancy (flame protection) and heat protection.

[0062] To obtain this additional function, the metal layer (1001) is positioned to face a heat source such as a flame. The metal layer (1001) preferably has a thickness of 0.1 mm to 2 mm. As the metal of the metal layer (1001), steel, galvanized (hot-dip galvanized or electroplated) steel, aluminum, zinc, tin, copper, chromium, magnesium, or alloys thereof can be used. Particularly suitable are metals or alloys with a melting point of less than 900°C, especially aluminum and zinc.

[0063] In particular, the metal layer (1001) may be pre-treated with an adhesion promoter / primer based on polyacrylate or polymethacrylate, polyvinylamine, phosphoric acid, or polyphosphate; a copolymer of maleic acid and acrylic acid and / or methacrylic acid and / or acrylic acid ester or methacrylic acid ester; a copolymer of maleic acid and styrene; or a copolymer of ethylene and acrylic acid and / or methacrylic acid and / or acrylic acid ester or maleic acid and / or maleic acid and polyvinylpyrrolidone. The adhesion promoter is typically applied as an aqueous solution via roll coating.

[0064] At least one polymer layer (1003) is provided on the metal layer (1001), and in the sense of the present invention, these layers ((1001), (1003)) are preferably in complete and close contact with each other.

[0065] Either the first solid layer (101) or the second solid layer (109) of the polymer foam laminated structure (1) of the present invention is provided on at least one polymer layer (1003) opposite the metal layer (1001). In other words, the metal layer (1001) and either the first solid layer (101) or the second solid layer (109) sandwich at least one polymer layer (1003).

[0066] At least one polymer layer (1003) contains an expandable material as a specific characteristic.

[0067] The term "expandable material," according to this invention, refers to a material that bulges or expands as a result of thermal exposure. This bulging or expansion results in an increase in volume and a decrease in density. In this invention, the expandable material serves to absorb, at least partially, the heat of a heat source.

[0068] The metal-polymer laminated structure (1) according to the present invention exhibits excellent flame retardancy with respect to any component located on the reverse side (which is the polymer foam laminated structure (1) side of the present invention).

[0069] As shown in embodiments of another application of the present applicant, when exposed to intense heat / flame, the metal layer (1001) may locally melt or melt down, while the expandable material contained in at least one polymer layer (1003) begins to expand and is thereby pushed out through the openings in the metal layer (1001). While expanding and being pushed out from the metal layer (1001), the expandable material serves to provide effective thermal insulation for the backing layer (105), which in turn protects any components on the back side, which is the side of the polymer foam laminated structure (1) of the present invention, from the high temperature of the heat source.

[0070] The heat insulation effect is due to the expandable material (e.g., expandable graphite) which repeatedly foams from the surface to the damaged area, restoring the expandable material layer (e.g., expandable graphite layer) damaged by the flame. The polymer foam laminated structure (1) of the present invention on the back side has a structural function above all else.

[0071] To strengthen the bond between the metal layer (1001) and at least one polymer layer (1003), an additional functional layer is interposed, specifically acting as an adhesive layer.

[0072] Further objectives, features, advantages and possible applications can be derived from the following description of preferred embodiments that do not limit the invention, as shown in the drawings. All features described and / or shown in the drawings, individually or in any combination, constitute the subject matter of the invention, regardless of their summary in the claims or their retrospective relationship. Figure 1 is a schematic diagram of a polymer foam laminated structure 1 according to an embodiment of the present invention. Figure 2 shows photographs of examples and comparative examples of polymer foam laminated structure 1. Figure 3 is a graph of the force-displacement curves for the embodiment and comparative example shown in Figure 2. Figure 4 is a graph of the absorbed energy for the examples and comparative examples in Figure 2. Figure 5a is a graph of the force-displacement curve of the test specimen "PA particle foam 13". Figure 5b is a photograph of the specimen on which the graph in Figure 5a is based. Figure 6a is a graph of the force-displacement curve of the test specimen "TPU foam". Figure 6b is a photograph of the specimen on which the graph in Figure 6a is based. Figure 7 is a photograph of the test apparatus into which the test specimen according to the present invention is inserted. Figure 8 is a graph comparing the bending action (workpiece).

[0073] Figure 1 shows a schematic overview of a polymer foam laminated structure 1 according to an embodiment of the present invention. Both the first solid layer 101 and the second solid layer 109 are shown at the top and bottom. Both of these layers are provided with at least one first functional layer 103 and at least one second functional layer 107 facing inward, respectively. A polymer foam layer 105 is positioned between them. [Examples]

[0074] Manufacturing of the polymer foam laminated structure 1 of the present invention The polymers shown in Table 1 were mixed in the amounts shown in Table 1 using a ZE 25A UXTI twin-screw extruder to form cylindrical pellets. Next, the obtained pellets (PZ1 and PZ2) were extruded into a film using a cast calender extruder. The film had a thickness of 400 μm and a width of 40 cm. The amounts shown in Table 1 are in mass percent.

[0075] P1: Polyamide 6 (BASF SE's Ultramid B24N) P2: PA6 / 6.36 (BASF SE Ultramid Flex F29) CO1: Low-density ethylene / n-butyl acrylate copolymer (Basell's Lucalen A2540 D) CO2: Ethylene propylene copolymer grafted with maleic anhydride (Exxon Chemicals' Exxelor 1801) A1: N,N'-1,6-Hexanediylbis[3,5-bis-4-hydroxyphenylpropanamide] (BASF SE Irganox B 1171 2X20KG 4G) A2: Talcum

[0076] [Table 1]

[0077] [Table 2]

[0078] Next, the sheets listed in Table 2 were integrated with the pre-treated metal tape as the first and second solid layers 101 and 109 using a heat-sensitive press to form a laminate. The metal tape and sheets were cut to the following dimensions: 300 mm × 200 mm. The temperatures shown in Table 3 were used. Sheets 1 and 2 were pre-dried overnight in dry air at 80°C. First, a scrim was produced and placed in a cold press along with spacers of the respective target thicknesses. The press was closed with a contact pressure of 100 kN and heated to the target temperature shown in Table 3. After holding this temperature for 60 seconds, the press was cooled to 50°C and the laminate was removed.

[0079] The following metal tapes and polymer tapes were used as the first and second solid layers 101 and 109.

[0080] M1: Zinc-plated steel sheet (Gardobond X4543 from Chemetal GmbH) pre-treated with phosphoric acid and acrylic acid aqueous solutions by roll coating; metal sheet thickness: 250 μm Aluminum (Gardobond X4595 from Chemetal GmbH) pre-treated with phosphoric acid and acrylic acid aqueous solutions by M2 roll coating; metal sheet thickness: 300 μm K1: Injection-molded tape (10mm x 10mm x 2mm) made from polyamide PA6-GF35 (BASF SE's Ultramid B3EG7 sw564).

[0081] In particular, the first and second solid layers 101 and 109 may be pre-treated with an adhesion promoter / primer based on polyacrylate or polymethacrylate, polyvinylamine, phosphoric acid, or polyphosphate; a copolymer of maleic acid and acrylic acid and / or methacrylic acid and / or acrylic acid ester or methacrylic acid ester; a copolymer of maleic acid and styrene; an adhesion promoter of ethylene and acrylic acid and / or methacrylic acid and / or acrylic acid ester or maleic acid and / or a copolymer of maleic acid and polyvinylpyrrolidone. The adhesion promoter is typically applied as an aqueous solution by roll coating.

[0082] [Table 3]

[0083] The laminates described in Table 3 were pressed into polymer foam laminated structures (PFLS). The polymer foam layers PSP1 to PSP3, described later in Table 4, were used as core layers. The side with the functional layer was laminated to the upper and lower surfaces of the polymer foam layer 105.

[0084] Polymer foam layers can be manufactured using any fusion method known to experts. More precisely, this involves manufacturing using automated molding machines based on steam technology. However, waterless methods are also possible, such as high-frequency fusion by Kurz or the Variotherm process by Fox Velution.

[0085] BASF SE's Infinergy 100 HD product was used as the pre-foamed polymer foam layer containing TPU.

[0086] The pre-foamed polymer foam layer containing PA was manufactured as follows.

[0087] The melt impregnation was carried out using a Leistritz twin-screw extruder (with a screw diameter of 18 mm, a length-to-diameter ratio of 40, and equipped with a melt pump, start valve, melt filter, porous die plate, and underwater pelletizer) divided into eight equally sized zones (Z1...Z8).

[0088] Polyamide was mixed with talcam in a polyethylene bag and fed to a twin-screw extruder via a dispensing device. The polyamide was melted in the first third of the extruder. After approximately one-third of the extruder length, the propellant was injected into the extruder under pressure with the help of an ISCO pump (Axel Semrau's piston pump). For the remainder of the extruder, the polymer molten was cooled by the temperature control of the twin-screw extruder. The temperature of the polymer molten corresponded to the temperature set in zone 8 as it passed through the perforated plate. The melt pump set the extruder's pressure profile (pressure-speed control) to ensure that the foaming agent was completely mixed with the polymer molten. In addition to setting the pressure profile in the twin-screw extruder, the melt pump also transported the foaming agent, pressing the polymer molten through subsequent devices (start valve, melt screen, perforated plate). The molten strand emerging from the perforated plate (each hole 1 mm in diameter) was introduced under pressure into a submersible pelletizer to obtain expanded polyamine granules (granule mass approximately 3.5 mg). The total processing capacity of the extruder was kept constant at approximately 4 kg / hour. The strands in the water box were cut by six blades attached to a blade ring. The blade ring rotated at approximately 3500 rpm, which generated expanded granules with a granular mass of 3.5 mg. These expanded granules were transported by a water circuit from the perforated plate to a dryer and separated into a collection container.

[0089] The following compositions were used in the preparation of PSP1, PSP2, and PSP4.

[0090] [Table 4]

[0091] Pre-expanded particles were loaded into the mold cavity by injection using compressed air (cavity dimensions: length 300 mm, width 200 mm, height 25 mm). A certain amount of crack filling was applied to the compressed particles. The mold was then placed in the molding machine. Saturated steam was then supplied into the cavity for a certain period of time (cross steam heating), and then saturated steam was supplied into the cavity for a certain period of time again (autoclave steam heating) to form the pre-expanded particles through thermal fusion. Cooling water was supplied into the mold cavity for a certain period of time to cool the resulting molded weld. The process conditions and characteristics of the particle foam molded product are summarized in Table 4.

[0092] PSP1: PA foam density 655g / l, thickness before pressing 10mm PSP2: PA foam density 590g / l, thickness before pressing 25mm PSP3: TPU foam density 300g / l, thickness before pressing 10mm PSP4: PA foam density 230g / l, thickness before pressing 10mm

[0093] [Table 5]

[0094] The polymer foam laminates shown in Table 5 were manufactured by placing the layers shown in Table 5 into a hot press at a pressure of 10 kN and heating them to the lamination temperature shown in Table 5. Polymer foam laminates (PFLS) with the respective total thicknesses shown in Table 5 were obtained.

[0095] [Table 6]

[0096] In the case of PFLS2, slight collapse of the foam was observed.

[0097] Figure 2 is a photograph showing examples and comparative examples of the polymer foam laminated structure 1 of the present invention. The specimen labeled "5_2" is a PA particle foam sandwiched between metal layers (i.e., sheet metal), the specimen labeled "13_1" is a PA particle foam used as the polymer foam layer 103, and the specimen labeled "Inf_3" is a TPU foam sandwiched between metal layers (i.e., sheet metal).

[0098] Figure 3 shows the force-displacement curves for the examples and comparative examples in Figure 2. Test specimen 5_2 (PA particle foam + sheet metal) shows high energy absorption and high rigidity, while test specimen 13_1 (pure PA particle foam without sheet metal (PA particle foam 5)) shows only low rigidity, and therefore low energy absorption. On the other hand, test specimen Inf_3 (i.e., Infinergy + sheet metal) has very low rigidity, but still shows high elasticity and good energy absorption.

[0099] Figure 4 shows graphs of the absorbed energy for the examples and comparative examples in Figure 2. As can already be seen from Figure 3, specimen 13_1 is superior to specimen 5_2.

[0100] Figure 5a shows a more detailed graph of the force-displacement curve for specimen 5_2, and Figure 5b is a photograph of the specimen on which this graph is based. This curve shows the variation in energy absorption for different but similar samples.

[0101] Figure 6a shows a more detailed graph of the force-displacement curve of the TPU foam specimen, and Figure 6b is a photograph of the specimen on which this graph is based.

[0102] Figure 7 shows a test apparatus for testing a specimen of the present invention, which is a polyamide sandwiched between steel. As shown in Figure 8, the specimen according to this invention exhibits the highest bending force compared to standard car body steel. There is no delamination, and the foam core is virtually intact. [Explanation of Symbols]

[0103] 1. Polymer foam laminated structure 101 1st solid layer 103 1st functional layer 105 Polymer foam layer 107 Second functional layer 109 Second solid layer 1001 Metal layer 1003 Polymer layer

Claims

1. - A first solid layer (101) covered by at least one first functional layer (103) and having a density exceeding 1000 g / l, - A polymer foam layer (105) provided on the at least one first functional layer (103), - A second solid layer (109) covered by at least one second functional layer (107) and having a density exceeding 1000 g / l, wherein the at least one second functional layer (107) is in contact with the polymer foam layer (105), and the second solid layer (109) Includes, The polymer foam layer (105) has a density of 20 g / l to less than 1000 g / l. The at least one first functional layer (103) and / or the at least one second functional layer (107) comprises a polyamide, particularly PA6, PA6 / 636, PA12, PA610, PA6 / 66, PA612, or a polyether block copolyamide. The polymer foam layer (105) contains polyamide, The first solid layer (101) and / or the second solid layer (109) is a metal layer having a thickness between 150 μm and 2000 μm, or the first solid layer (101) and / or the second solid layer (109) is a solid polymer layer having a thickness between 1 mm and 10 mm. A polymer foam laminated structure (1) wherein the at least one first functional layer (103) and / or the at least one second functional layer (107) further comprises a homopolymer or copolymer of ethylene and / or α-olefin and / or acrylic acid ester and / or maleic anhydride.

2. The polymer foam laminated structure (1) according to claim 1, wherein the polymer foam layer (105) has a softening point of 100°C to 280°C.

3. The polymer foam layer (105) is - Melting pre-foamed polymer particles, or - Extruding a thermoplastic polymer through a slot die in the presence of a foaming agent, or - Filling a thermoplastic polymer with a foaming agent at a temperature exceeding its softening temperature in an autoclave, followed by expansion and molding, - Using a foam injection molding machine, A polymer foam laminated structure (1) according to claim 1 or 2, obtained by the method described above.

4. The polymer foam laminated structure (1) according to claim 1, wherein the homopolymer or copolymer is grafted with maleic anhydride.

5. The polymer foam laminated structure (1) according to any one of claims 1 to 4, wherein the at least one first functional layer (103) and / or the at least one second functional layer (107) has a thickness between 20 μm and 2000 μm.

6. The polymer foam laminated structure (1) according to claim 1, wherein the solid polymer layer as the first solid layer (101) and / or the second solid layer (109) comprises a polymer material reinforced with carbon fibers, glass fibers, aramid fibers, basalt fibers, natural fibers, metal fibers, potassium titanate particles and mixtures thereof.

7. The polymer foam laminated structure (1) according to any one of claims 1 to 5, wherein the first functional layer (103) and the second functional layer (107) comprise an unreinforced polymer.

8. a1) The step of providing a first solid layer (101), a2) The step of providing a second solid layer (109), b1) The step of providing at least one first functional layer (103) on the first solid layer (101), b2) Providing at least one second functional layer (107) on the second solid layer (109), c) Providing a polymer foam layer (105) on top of the at least one first functional layer (103) and below the at least one second functional layer (107), It has, thereby obtaining a pre-laminated structure, d) The step of pressing the pre-laminated structure at the raised temperature, e) A step of obtaining a polymer foam laminated structure (1), A method for producing a polymer foam laminated structure (1) according to any one of claims 1 to 7, comprising:

9. a1) The step of providing a first solid layer (101), b1) The step of providing at least one first functional layer (103) on the first solid layer (101), c1) A step of providing pre-foamed thermoplastic beads of polymer foam material for a polymer foam layer (105), wherein the thermoplastic beads have a raw material density of 200 g / l to 400 g / l, d1) A step of providing a polymer foam layer (105) by directly fusing the pre-foamed beads onto the at least one first functional layer (103) with hot steam or heat irradiation (IR), e) A step of obtaining a polymer foam laminated structure (1), A method for producing a polymer foam laminated structure (1) according to any one of claims 1 to 7, comprising:

10. Use of the polymer foam laminated structure (1) according to any one of claims 1 to 7 as an energy absorption device.

11. - A polymer foam laminated structure (1) according to any one of claims 1 to 7, - At least one polymer layer (1003) provided on either the first solid layer (101) or the second solid layer (109) of the polymer foam laminated structure (1), - A metal layer (1001) provided on the at least one polymer layer (1003) on the opposite side of the polymer foam laminated structure (1) according to any one of claims 1 to 7, Includes, The composite component (1000) comprises at least one polymer layer (1003) containing an expandable material.

Images