Resin and metal composite panel

Abstract

To inexpensively manufacture a lightweight and highly rigid metal resin composite panel that serves as a laminated panel for floor and wall materials of building, vehicles and ships, exhibiting superior corrosion resistance and high rigidity.SOLUTION: A resin metal composite panel is formed by pouring and foaming a hard urethane resin between two covering materials composed of metal plates. Each covering material is a single-sided film-laminated steel plate with a plate thickness of 0.1 mm or greater or a single-sided film-laminated aluminum plate with a plate thickness of 0.24 mm or greater, wherein a thermoplastic resin layer of a specific thickness is provided on the outer surface side of the panel, and the inner surface side for bonding to a core resin layer has a surface tension of 50 mN / m or greater and includes a layer with specific amounts of inorganic hydrated oxide and inorganic oxide attached thereto. A hard foamed urethane resin of the core layer has a thickness of 3 mm or greater and has a dynamic vertical elastic modulus measured at 80°C and 1 Hz of 100 MPa or greater, and the density of the hard foamed urethane resin after foaming is within a specific range.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a material for laminated panels used as a weight reduction measure for building materials, floor and wall materials for ships and vehicles, and in particular to a material for laminated panels having a foamed resin core between two metal plates. resin The present invention relates to a laminated panel having a layer. [Background technology]

[0002] A core is placed between two metal plates to reduce the weight of building materials, ships, and vehicle floors and walls. resin Lightweight laminated panels made by gluing together layers of foamed resin, aluminum honeycomb, and paper honeycomb have been proposed and put into practical use.

[0003] core resin As an example of a resin-metal composite panel using a foamed resin as a layer, there is an example of a foamed resin laminated metal panel in which an adhesive layer and a non-foamed resin layer are provided between a metal plate and a foamed resin in this order from the metal plate side, as described in Patent Document 1. resin As a laminated panel using honeycomb in layers, Patent Document 2 discloses a sheet-like core having a honeycomb structure. resin An example of a method for manufacturing a sandwich panel is shown, in which sheet-like prepregs are cured on both sides of the layers.

[0004] core resin In the case of resin-metal composite panels using foam resin as the layer, Material and Core resin If the adhesive strength of the layers is low, the core may break down when the panel is subjected to an impact or a large load. resin Layers and epidermis Material The core may peel off from the interface. resin It is necessary to increase the adhesive strength between the layer and the skin plate.

[0005] Patent Document 3 shows an example of a resin sheet-laminated steel plate formed by sequentially laminating at least a resin sheet (b) having a metal plate embedded therein on both sides of a resin sheet (a) and a steel plate located on the side of the resin sheet (b) opposite to the side in contact with the resin sheet (a), and describes that the metal plate embedded in the resin sheet (b) has formed therein pores having a volume ratio of 30 volume % or more relative to the total volume of the metal plate.

[0006] Patent Document 4 describes a method for producing a laminated panel by applying a primer or paint to the surface of a metal plate that comes into contact with a hard urethane foam resin. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4326001 [Patent Document 2] Japanese Patent Application Publication No. 2018-187939 [Patent Document 3] Patent No. 5553542 [Patent Document 4] Patent No. 4044724

[0008] Incidentally, in the laminated panel shown in Patent Document 1, in order to prevent the foamed resin layer from peeling off from the metal plate, a non-foamed resin layer is laminated between the metal plate and the foamed resin with an adhesive. This requires many adhesive bonding steps and a separate foaming step, resulting in high manufacturing costs.

[0009] In addition, Patent Document 2 discloses a sheet-shaped core having a honeycomb structure. resin Layer and sheet prepreg core resin The method for manufacturing a sandwich panel is shown, in which the layers are pressed from the top and bottom while being heated and pressurized. resin The honeycomb material of the layers and the prepreg skin material are expensive, and the heating time is long, so both the material cost and the manufacturing cost are high.

[0010] The laminated panel shown in Patent Document 3 is a resin sheet laminated steel plate obtained by sequentially laminating at least a resin sheet (b) having a metal plate embedded therein on both sides of a resin sheet (a) and a steel plate located on the side of the resin sheet (b) opposite to the side in contact with the resin sheet (a). However, since the metal plate embedded in the resin sheet (b) requires a step of pre-processing to create holes with a volume ratio of 30 volume % or more relative to the total volume of the metal plate, the cost of the resin sheet (b) in the laminated panel is high, making it difficult to achieve low-cost laminated panels. In addition, the resin sheet laminated steel sheet in this patent is intended for use in automotive exterior panels, housings for home appliances, furniture, and office equipment parts, so it must be capable of bending and deep drawing. resin The resin sheet (a) is flexible and has a relatively thin thickness of preferably 0.2 to 1.5 mm, and the total panel thickness is about 3 mm or less. Therefore, it is suitable for laminated panels for building materials, ships, and vehicles, which have a high load capacity and at least a core. resin It is not suitable for applications requiring a layer thickness of approximately 5 mm or more.

[0011] The invention disclosed in Patent Document 4 describes a method for manufacturing a laminated panel by applying a primer or paint to the surface of a metal plate that comes into contact with the rigid urethane foam resin. However, after applying the primer to the metal plate, the metal plate must be dried and baked. Furthermore, to stabilize the adhesive strength between the metal plate and the rigid urethane foam resin, it is necessary to prevent oxidation of the metal plate surface and insufficient curing of the primer coating, which makes quality control of the adhesive state complicated. While applying a primer or paint to the surface of the metal plate that comes into contact with the rigid urethane foam resin is expected to improve adhesion to the urethane resin, when the urethane resin liquid is injected between two metal plates, the primer layer softens due to the reaction heat of the urethane liquid, increasing the flow resistance of the urethane resin liquid and making the urethane resin more likely to stagnate. The foamed bubbles tend to merge and grow larger at the stagnation points. Therefore, in panels with thin rigid urethane foam resin layers, the rigidity of the areas where giant bubbles exist is reduced, making the panel more susceptible to buckling.

[0012] Furthermore, the document describes the use of a steel sheet with a plating treatment such as zinc plating on both sides as the skin steel sheet, but if the outer surface of the skin steel sheet of the panel is a zinc-plated steel sheet, when salt water or water gets on the panel, it can reach the zinc-plated surface through the carpet fabric attached to the top surface, causing the zinc plating to corrode and swell. The corrosion products of zinc are brittle, so this is undesirable because it makes the carpet or other covering attached to the outer surface of the panel prone to peeling off. Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a laminated panel that is inexpensive and has excellent impact resistance, which is a metal-resin composite panel with high buckling strength that can suppress the instability of adhesive strength and the enlargement of bubbles in the rigid foamed resin layer that are likely to occur in the panel manufacturing method shown in Patent Document 4 in particular, and can stably obtain high adhesive strength between the metal plate and the rigid foamed urethane resin. [Means for solving the problem]

[0014] In order to solve the above problems and issues, the present invention provides a method for manufacturing a foamed rigid urethane resin core. resin The skin material and core of the laminated panel resin By optimizing the composition of the foamed rigid urethane resin in the layers, the core of the laminated panel resin The present invention makes it possible to provide a laminated panel with high adhesive strength between layers and excellent impact resistance at a low cost. resin Since there is no extra manufacturing process such as heat-pressing prepreg sheets onto layers, it is possible to provide laminated panels at low cost, and the core resin The adhesive strength between the layer and the skin material is excellent, and the core resin Since the variation in bubble size of the layers can be reduced, laminated panels with high impact resistance can be produced inexpensively.

[0015] The present invention has been made based on the above findings, and the gist of the present invention is as follows. That is, (1) The skin material is two single-sided resin film laminated metal sheets having a thermoplastic resin layer with a film thickness of 8 μm or more and 150 μm or less on one surface of a metal sheet made of a steel sheet or an aluminum sheet, The side with the thermoplastic resin layer is the outer surface of the resin-metal composite panel, The surface tension of the surface material on the side without the thermoplastic resin layer is 50 mN / m or more, as measured by JIS K 6768 "Plastics - Films and Sheets - Wetting Tension Test Method", and is 1.5 mg / m 2 More than 130mg / m 2 The following layers of inorganic hydrated oxides and inorganic oxides are applied: Between the two layers of inorganic hydrated oxide and inorganic oxide skin material, a core resin layer is formed, which has a thickness of 3 mm or more, a dynamic longitudinal modulus of elasticity measured at 80°C and 1 Hz of 100 MPa or more, and a density after foaming of 0.2 g / cm 3 More than 0.7g / cm 3 A resin-metal composite panel having a rigid urethane foam resin injected therein, the rigid urethane foam resin being: , (2) The aforementioned epidermis Material Above The aforementioned The resin-metal composite panel according to (1), characterized in that the inorganic hydrated oxide and inorganic oxide are a layer made of inorganic hydrated oxide and inorganic oxide containing one or more kinds selected from chromium hydrated oxide, zirconium hydrated oxide, titanium hydrated oxide, tungsten hydrated oxide, cerium hydrated oxide, and silica; (3) the single-sided resin film Laminated metal sheet Resin-metal composite The resin-metal composite panel according to (1) or (2), characterized in that a thermoplastic film having a surface tension of 40 mN / m or more is heat-sealed to the outer surface of the panel; (4) The aforementioned The resin-metal composite panel according to (3), wherein the film is made of one or a blend of two or more resins selected from thermoplastic polyester resins, polyethylene resins with modified resin layers, polypropylene resins with modified resin layers, ethylene-propylene copolymer resins with modified resin layers, ionomer resins, and vinyl chloride resins; is. [Effects of the Invention]

[0016] The resin film laminated metal sheet for a resin metal laminated panel of the present invention is a core of a resin metal laminated panel resin Layers and epidermis Material It is therefore possible to provide a lightweight, highly rigid panel at low cost, which has high adhesive strength and stable panel rigidity and strength, and is therefore extremely useful as a laminated lightweight panel for building materials, ships, and vehicle floor and wall materials. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 10 is a diagram showing the relationship between the thickness of the skin material of a resin-metal composite panel and the dent resistance of the laminated panel. [Figure 2] FIG. 1 is a diagram showing the relationship between film wrinkle resistance and film thickness during the production of a resin film laminated steel sheet that is a skin material of a resin-metal composite panel. [Figure 3] FIG. 1 is a diagram showing the relationship between film burr resistance and film thickness when cutting a resin film laminated steel sheet that is a skin material of a resin-metal composite panel during production. [Figure 4] 1 is a diagram showing the relationship between the surface tension on the inner surface side of the panel skin of a resin-metal composite panel and the adhesion between the panel skin material and the foamed rigid urethane resin layer. [Figure 5] FIG. 1 is a diagram showing the relationship between the amount of inorganic hydrated oxide and inorganic oxide attached to the inner surface of the skin of a resin-metal composite panel and the impact resistance of the panel. [Figure 6] 1 is a graph showing the relationship between the dynamic elastic modulus at 80°C and 1 Hz of the urethane foam resin layer resin of a resin-metal composite panel and the deflection resistance of the panel at 80°C. [Figure 7] 10 is a diagram showing the relationship between the thickness of the urethane foam resin layer of a resin-metal composite panel and the impact resistance of the panel. FIG. [Figure 8] 1 is a diagram showing the relationship between the density of the urethane foam resin layer of a resin-metal composite panel and the impact resistance of the panel. [Figure 9] 1 is a cross-sectional schematic diagram of a resin metal laminated panel using a resin film laminated metal plate. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, the configuration of the resin-coated metal sheet for a resin-metal composite panel of the present invention will be described in detail.

[0019] The skin material constituting the resin-metal composite panel of the present invention is preferably a metal plate because of its excellent strength, rigidity, processability, adhesion, and cost, and in particular, a steel plate or an aluminum plate is preferred in terms of strength, processability, cost, etc.

[0020] When a steel sheet is used as the skin material of a resin-metal composite panel, the strength and elongation of the steel sheet may be appropriately determined within a range that does not impair cuttability and processability.

[0021] The resin-metal composite panel of the present invention is expected to be used in a variety of environments, and therefore requires corrosion resistance equivalent to that of building material panels. Therefore, it is desirable to coat the outer surface of the panel with a resin. However, since resin coating the panel surface after panel manufacture increases manufacturing costs, it is preferable to use a laminated steel sheet in which the steel sheet surface is pre-coated with a resin. Methods for coating the steel sheet surface with resin include applying a resin paint and a resin film lamination method in which a thermoplastic resin film is heat-sealed to the steel sheet. However, a method of thermally laminating a thermoplastic resin film is preferred, as it does not require auxiliary equipment such as a drying oven and is free from the risk of environmental pollution by solvents.

[0022] epidermis Material Regarding the thickness of the epidermis Material In the case of steel plates, if the thickness is less than 0.1 mm, there is a risk that the surface material may be locally dented or perforated when a hard, heavy object with corners falls on the resin-metal composite panel, so the thickness of the steel plate is preferably 0.1 mm or more. Material In the case of an aluminum plate, the thickness is preferably 0.24 mm or more.

[0023] Figure 1 shows the surface of the resin-metal composite panel. Material As can be seen from Figure 1, the relationship between the thickness of the surface and the dent resistance of the panel is Material In the case of steel plates, if the plate thickness is 0.1 mm or more, the dent resistance of the steel plate surface is guaranteed, and the surface Material In the case of aluminum plates, it is clear that the dent resistance of the aluminum plate skin can be guaranteed with a plate thickness of 0.24 mm or more.

[0024] From the viewpoint of panel rigidity, there is no particular upper limit on the thickness of the skin material, but from the viewpoint of lightweight and high rigidity, which is the objective of resin-metal composite panels, an unnecessarily thick skin material is undesirable because it negates the benefit of weight reduction. Therefore, when the skin material is steel plate, the upper limit on the thickness is preferably about 1 mm or less, and when the skin material is aluminum plate, the upper limit on the thickness is preferably about 3.0 mm or less.

[0025] epidermis Material The surface to be bonded to the foamed rigid urethane resin layer is preferably cleaned in advance by alkaline degreasing, water washing and drying in order to stabilize the adhesion to the urethane resin.

[0026] In particular, aluminum plates have poor adhesion to resin due to the oxide coating on their surface. Material In this case, it is preferable to clean the surface by alkaline degreasing, polishing, etc., and then provide a layer made of an inorganic hydrated oxide and an inorganic oxide on the surface, since this forms a hydrogen bond between the urethane bond of the urethane resin and the hydroxyl group of the chromium hydrate, thereby providing strong adhesion.

[0027] Next, the surface of the resin-metal composite panel of the present invention Material This section describes the resin layer to be laminated onto the substrate.

[0028] The surface of the resin-metal composite panel of the present invention Material The resin to be laminated on the surface is preferably a thermoplastic resin film because of the ease of thermal lamination.

[0029] epidermis MaterialThermoplastic resins with excellent adhesion to metal sheets and water resistance are preferred, including those containing hydrogen-bondable polar groups in the molecular chain, such as polyester resins, polyamide resins, ionomer resins, modified polyolefin (polyethylene, polypropylene) resins, and vinyl chloride resins. These resins provide excellent adhesion between the metal sheet and the resin. In particular, polyester resin films (homo-PET (polyethylene terephthalate) film, PET-IA (polyethylene terephthalate-isophthalate copolymer) film, PBT (polybutylene terephthalate copolymer) film, and films of these copolymer resins or blends of these resins) and modified polyolefin resin films (polyethylene, polypropylene, polyethylene-polypropylene copolymer) with a modified resin layer on the adhesive surface are preferred for their excellent adhesion to metal sheets, adhesion strength, and corrosion resistance. For these reasons, the film is preferably made of one or a blend of two or more resins selected from thermoplastic polyester resins, polyethylene resins with a modified resin layer, polypropylene resins with a modified resin layer, ethylene-propylene copolymer resins with a modified resin layer, ionomer resins, and vinyl chloride resins. The thermoplastic resin film may contain inorganic fillers such as titanium white, silica, and carbon black, or coloring pigments.

[0030] The surface of the resin-metal composite panel of the present invention Material The film laminated to the outer surface of the panel is preferably thermoplastic. This is because when a nonwoven fabric or carpet is attached to the surface of the panel with a hot melt adhesive, a thermoplastic film is more likely to fuse with the hot melt adhesive. Furthermore, a thermoplastic film with a surface tension of 40 mN / m or more is preferred. If the surface tension of the film is less than 40 mN / m, the film on the panel surface is more likely to peel off when the panel is subjected to an impact, reducing the panel's anti-corrosion properties, which is undesirable.

[0031] Resin-metal composite panel skin MaterialThe thickness of the film laminated on the outer surface of the sheet is preferably 8 μm or more and 150 μm or less. If the film thickness is less than 8 μm, the film is likely to wrinkle during lamination, and if the wrinkled areas are laminated, not only will the appearance become unsightly, but the film will also be prone to tearing, which may cause corrosion of the steel sheet, which is undesirable. Also, if the film thickness exceeds 150 μm, when the laminated steel sheet is cut, the film will remain uncut and will be prone to peeling at the cut edge, which is undesirable.

[0032] Figure 2 shows the relationship between the degree of wrinkles that occurred on the film laminate surface and film thickness when 1000m of stretched homo-PET film was continuously heat-sealed to a 0.15mm thick TFS (tin-free steel) steel plate while applying tension in a continuous film laminating machine. As can be seen from Figure 2, if the film thickness is less than 8 μm, overlapping and wrinkles tend to occur on the laminated surface, which is undesirable. For this reason, it is preferable that the thickness of the film to be laminated to the skin material is 8 μm or more.

[0033] Figure 3 shows the relationship between the film burrs that occur when a film-laminated steel sheet, in which a 0.15 mm thick TFS and a 20 μm thick homo-PET film are heat-sealed to both sides of the TFS in a continuous line, is cut with a shearing machine and the film thickness. As can be seen from Figure 3, if the film thickness exceeds 150 μm, burrs are likely to occur in the film, and in particular, force acts in the direction that tears the film off at the bottom end of the cut edge, making film peeling more likely to occur near the cut edge.If moisture adheres to the edge, it will penetrate into the interface between the film and the steel sheet, making the steel sheet surface more susceptible to rust, which is undesirable.

[0034] From the above, the surface of the resin-metal composite panel of the present invention Material The thickness of the film to be laminated on the surface is preferably 8 μm or more and 150 μm or less.

[0035] Next, we will discuss the metal sheet that is the skin material of the resin-metal composite panel.

[0036] Resin-metal composite panel skin Material It is preferable that a coating containing an inorganic hydrated oxide is provided on the side that comes into contact with the rigid urethane foam resin, because the hydroxyl groups of the inorganic hydrated oxide form hydrogen bonds with the urethane bonds of the rigid urethane foam resin, resulting in strong adhesion.

[0037] Epidermis with inorganic hydrated oxides and inorganic oxides Material The surface tension of the inorganic hydrated oxide and inorganic oxide layer is preferably 50 mN / m or more as measured in accordance with JISK 6768 "Plastics - Films and Sheets - Wetting Tension Test Method," and the inorganic hydrated oxide and inorganic oxide layer may have a metal plating layer of the same type underneath in order to improve the adhesion between the inorganic hydrated oxide and inorganic oxide layer.

[0038] Resin-metal composite panel skin Material If the surface tension of the surface that comes into contact with the rigid urethane foam resin is less than 50 mN / m, the surface will not break down in a load-bearing test in which a heavy object is placed on the panel or in an impact resistance test in which a heavy object is dropped from the top of the panel. Material This is undesirable because it can easily cause the urethane foam resin layer to peel off at the interface, causing the panel to suddenly buckle and deform, which is dangerous.

[0039] Resin-metal composite panel skin Material The upper limit of the surface tension on the side that comes into contact with the rigid urethane foam resin is 70 mN / m or less, which can be controlled using a mixture for wetting tension testing (Fujifilm, manufactured by Wako Pure Chemical Industries, Ltd.). Furthermore, even if the surface of the metal plate is degreased and cleaned to increase the surface tension and the surface tension is measured precisely using the contact angle method, the adhesion between the surface v and the rigid urethane foam resin is hardly improved. Material Resin-metal composite panel skin Material The upper limit of the surface tension on the side in contact with the rigid urethane foam resin is industrially acceptable if it is 70 mN / m or less as measured according to JIS K6768 "Plastics - Films and sheets - Wet tension test method."

[0040] Figure 4 shows the results after degreasing at 2 mg / m 2 to 50 mg / m 2This figure shows the relationship between the surface tension on the inner side of the panel skin and the adhesion between the panel skin material and the rigid urethane foam resin layer of a resin-metal composite panel made by injecting and solidifying a foamed rigid urethane resin between two cold-rolled steel sheet skin materials with different surface tensions that have been subjected to various chemical conversion treatments within the range of 100 to 150°C. As can be seen from Figure 4, if the surface tension of the surface of the skin material to be bonded to the rigid urethane foam resin layer is 50 mN / m or more, the adhesion to the rigid urethane foam resin layer is good and the impact resistance of the resin-metal composite panel is good, which is preferable.

[0041] epidermis Material The inorganic hydrated oxides and inorganic oxides are selected from the group consisting of chromium hydrated oxides and oxides, zirconium hydrated oxides and oxides, titanium hydrated oxides and oxides, tungsten hydrated oxides and oxides, cerium hydrated oxides and oxides, and silica, and are composed of one or more of these in an amount of 1.5 mg / m 2 More than 130mg / m 2 The following coatings are preferred: inorganic oxides and inorganic hydrated oxides with a coverage of 1.5 mg / m 2 If the coating weight is less than 130 mg / m, the surface of the steel sheet is prone to oxidation before the laminated panel is manufactured, which is undesirable as it reduces adhesion to the rigid urethane foam resin. 2 If the thickness exceeds this value, the inorganic hydrated oxide and inorganic oxide layer will undergo cohesive failure and peeling will occur easily when bonded to the rigid urethane foam resin layer, which is undesirable as it reduces the buckling strength of the panel.

[0042] Fig. 5 shows a 0.3 g / cm2 density steel sheet made from a 0.15 mm thick cold-rolled steel sheet that had been electrolytically degreased in a 5% aqueous solution of sodium hydroxide, then pickled in 5% sulfuric acid, and washed with water. The steel sheet was then subjected to cathodic electrolysis in zirconium fluoride to form a film of zirconium oxide and hydroxide on its surface. 3 Hard urethane foam resin (5mm thick) core resin 1 is a graph showing the relationship between the amount of zirconium (Zr)-based inorganic oxide and hydroxide attached to a 40 cm x 80 cm resin-metal composite panel as a layer and the impact resistance of the laminated panel. As can be seen from Figure 5, the deposition amount of inorganic hydroxides and oxides was 1.5 mg / m 2 Less than or equal to 130 mg / m 2 If it exceeds this value, the impact resistance of the panel decreases, which is not preferable.

[0043] Next, the core of the resin-metal composite panel of the present invention resin The rigid urethane foam resin of the layer will be described.

[0044] core resin The thickness of the rigid urethane foam resin layer is preferably 3 mm or more. If the thickness of the resin layer is less than 3 mm, the rigidity of the panel will be low, the load-bearing capacity of the panel will be small, and the panel may buckle when subjected to the impact of a dropped heavy object (approximately 20 kg), which is not preferable.

[0045] Furthermore, the rigid urethane foam resin preferably has a dynamic modulus of elasticity of 100 MPa or more and 5000 MPa or less at 80°C and 1 Hz, as measured using a forced vibration viscoelasticity measuring device. If the dynamic modulus of elasticity of the rigid urethane foam resin at 80°C measured at 1 Hz is less than 100 MPa, the panel may bend if a heavy object is left on it during summer, when the panel temperature is high. Furthermore, if the dynamic modulus of elasticity of the rigid urethane foam resin at 80°C measured at 1 Hz exceeds 5000 MPa, the panel's impact resistance against heavy objects may be reduced during colder temperatures, such as winter.

[0046] The resistance to deflection of resin-metal composite panels in high-temperature summer environments was evaluated by measuring the bending rigidity of the panel at room temperature and 80°C, and calculating the ratio of the bending rigidity of the panel at 80°C to the bending rigidity of the panel at room temperature.

[0047] As can be seen from Figure 6, if the dynamic elastic modulus at 80°C and 1 Hz is less than 100 MPa, the bending rigidity of the resin-metal composite panel in a high-temperature environment of 80°C will be less than 50% of that at room temperature, and sufficient panel rigidity cannot be ensured, which is undesirable.

[0048] Next, regarding the thickness of the rigid urethane foam resin layer of the resin-metal composite panel, the resin density of the urethane resin layer is 0.2 g / cm 3 If the thickness of the rigid urethane foam resin layer is more than 3 mm, the thickness of the rigid urethane foam resin layer is preferably 3 mm or more. If the thickness of the rigid urethane foam resin layer is less than 3 mm, the rigidity of the panel decreases, and the impact resistance when a heavy object is dropped is insufficient, which is not preferable.

[0049] Figure 7 shows the relationship between the thickness of the rigid urethane foam resin layer of a resin-metal composite panel and the impact resistance of the panel. As can be seen from Figure 7, if the thickness of the rigid urethane foam resin layer is less than 3 mm, the impact resistance of the panel will be poor, which is not preferable.

[0050] The density of the rigid urethane foam resin in the resin-metal composite panel is 0.2 g / cm 3 More than 0.7g / cm 3 The density of the rigid urethane foam resin is preferably 0.2 g / cm or less. 3 If it is less than this, the bubbles will become too large and the core resin This is undesirable because it weakens the strength of the layers and may cause the panel to buckle if a heavy object is dropped and impacts the resin-metal composite panel.

[0051] On the other hand, the density of hard urethane resin is 0.7 g / cm 3 If the density exceeds this value, not only will the distribution of bubbles become uneven, which is undesirable, but the panel weight will also increase and the resin cost will also increase, which is undesirable. Figure 8 shows the relationship between the density of the rigid urethane foam resin and the impact resistance of a resin-metal composite panel with a rigid urethane foam resin layer thickness of 3 mm. As can be seen from Figure 8, when the density of the rigid urethane foam resin is 0.2 g / cm 3 If it is less than this, the impact resistance of the resin-metal composite panel when a heavy object is dropped will be poor, which is not preferable.

[0052] In addition, the ratio of the total thickness of the skin material of the resin-metal composite panel to the thickness of the hard urethane foam resin layer is not particularly limited. However, even if the panel skin thickness of the resin-metal composite panel is increased, the contribution rate to the rigidity of the entire panel does not change much. Therefore, the ratio of the total thickness of the skin material of the resin-metal composite panel to the hard urethane foam resin layer and the skin Material Thickness ratio to total thickness (thickness of rigid urethane foam resin layer / skin Material The total thickness is preferably 8 or more.

[0053] Next, a method for manufacturing the resin composite panel will be described.

[0054] Resin-metal composite panels can be produced by first fixing the metal sheet that serves as the skin material to the top surface of the upper mold and the bottom surface of the lower mold of a special mold using suction or other methods, then closing the upper and lower molds and injecting a foamable resin liquid between the upper and lower molds.

[0055] Skins placed on the top and bottom of the mold Material The resin to be injected between the core and the mold must be easy to fill, take a short time to complete foam hardening, and have a good hardness of the core after hardening. resin Rigid urethane foam resin is most preferred because of its high layer strength and rigidity. Rigid urethane foam resin is made by mixing polyisocyanate, polyol, catalyst (amine compound), blowing agent (water or fluorocarbon), and foam stabilizer (silicone) just before injection, and then quickly injecting it to fill the gap between the two skins. If the time between mixing the raw material liquid and injection is too long, the liquid will begin to harden and foam, causing a sudden increase in viscosity, which could prevent the resin from being distributed evenly throughout the panel and could cause bubbles to grow in size in areas of the panel where fluidity has decreased, which is undesirable.

[0056] The test method will be specifically described below.

[0057] [Surface tension measurement] The surface tension of the inner surface of the metal plate used as the skin material of the resin-metal composite panel, which is to be bonded to the core resin layer, was measured according to JISK 6768 "Plastics - Films and Sheets - Wet Tension Test Method" and was judged from the wettability of the wet tension test mixture (Fujifilm, manufactured by Wako Pure Chemical Industries, Ltd.).

[0058] [Production of resin film laminated metal sheet] A thermoplastic unstretched film was heat-sealed to one side of a steel plate heated to 300°C in a hot press and an aluminum plate using a Teflon (registered trademark) rubber roll at a linear pressure of 100 N / cm to produce a film-laminated metal plate measuring 240 mm x 300 mm, and a sample plate measuring 200 mm x 200 mm was cut from near the center.

[0059] [Laminated panel production] The prepared 200 x 200 mm resin film laminated metal plate was attached by suction to the upper and lower dies of a panel manufacturing mold, which had upper and lower dies with steel plate suction holes, so that the film side of the resin film laminated metal plate was in contact with the mold surface, and the upper and lower dies were closed.The resin mixed in the mixing tank was then injected through the resin injection port provided on the mold.

[0060] [Peel strength measurement of resin film laminated metal sheet] The prepared resin-metal laminated panel was cut using a high-speed precision cutting machine (Heiwa Technica Co., Ltd. Fine Cut) to obtain test pieces measuring 25 mm wide and 150 mm long, and the resin film-laminated steel sheets on both sides of the end of the test piece were peeled off by approximately 30 mm to prepare the chuck gripping portion of the tensile testing machine. The gripping parts of the resin film laminated metal plate on both sides of the test piece are clamped in the chuck of the tensile testing machine and peeled off 100 mm (movement between chucks: 200 mm) at a pulling speed of 20 mm / min. resin The peel strength of the layer to the foamed rigid urethane resin was measured, and a peel strength of 10N / 25mm or more was judged as good, 5N / 25mm or more but less than 10N / 25mm as acceptable, and less than 5N / 25mm as unacceptable. (Peel strength of 5N / 25mm or more means that the panel skin and core will not peel off when a 20kg polyethylene tank is dropped from a height of 30cm from the top of the panel. resin (This corresponds to the minimum peel strength required to prevent the layers from peeling off.)

[0061] [Impact resistance test of laminated panels] For the impact resistance test, a 50mm x 200mm test piece was cut from a resin-metal laminated panel using a high-speed precision cutting machine and placed in a DuPont impact testing machine equipped with a die having a roll-shaped support section with a support point distance of 100mm and a 2.5mm radius at the tip, and a semi-cylindrical punch with a 5mm radius as an impact indenter. A 1kg weight was then dropped from a height of 60mm from the impact receiving surface above the impact indenter, and the test piece was judged to be pass or fail based on whether it buckled.

[0062] [Dent resistance test of laminated panels] A 5cm x 5cm sample was cut from the resin-metal laminated panel using a high-speed precision cutting machine, and a dent impact was applied to the center of the laminated panel sample using a DuPont impact tester (punch tip diameter = 12.5mm, falling weight conditions = 300g x height 40mm). The dent resistance was determined based on the degree of deformation of the labeled metal plate.

[0063] [Laminated panel high temperature (80°C) panel deflection resistance evaluation test / panel three-point bending test] The panel's resistance to deflection was evaluated by measuring the bending stiffness of the stroke-load diagram in a three-point bending test. Resin-metal composite panel specimens, 50 mm wide and 200 mm long, were cut with a high-speed precision cutter and placed in a tensile testing machine equipped with a thermostatic chamber. The specimens were compressed at a distance of 100 mm between support points, using a semi-cylindrical punch with a 25 mm tip diameter at a punch stroke rate of 50 mm / min. The bending stiffness was measured by determining the slope of the linear portion of the elastic deformation region of the stroke-load diagram. The test was conducted at room temperature and 80°C in the thermostatic chamber. The specimens were placed on the three-point bending test fixture and the test was conducted 10 minutes after the thermostatic chamber temperature reached the specified temperature. The panel's resistance to deflection at high temperatures (80°C) was evaluated as follows: Good if the bending rigidity of the panel at 80°C was 80% or more of the bending rigidity at room temperature; Pass if the bending rigidity of the panel at 80°C was 50% or more but less than 80% of the bending rigidity at room temperature; Fail if the bending rigidity was 50% or more but less than 80% of the bending rigidity at room temperature.

[0064] [Dynamic viscoelasticity test] The dynamic elastic modulus of the rigid urethane foam resin at 80°C and 1 Hz was measured using a forced stretching vibration type viscoelasticity measuring device (DMA7100 manufactured by Hitachi High-Tech Science Corporation). The sample had a density of 0.5 g / cm. 3 A sample measuring 2 mm thick, 10 mm wide, and 40 mm long was cut from the rigid urethane foam resin using a utility knife. The dynamic modulus was measured by attaching the sample to the chuck of the equipment with a chuck distance of 20 mm, and measuring the frequency at 1 Hz, strain at 0.05%, and temperature at a rate of 3°C / min over a temperature range of 0°C to 120°C. The dynamic modulus at 25°C and 80°C was then read from the frequency vs. dynamic modulus graph and used as the dynamic modulus at room temperature and 80°C.

[0065] The present invention is a resin-metal composite panel formed by injecting and foaming a rigid urethane resin between two metal sheets of skin material, and the skin material has a thermoplastic resin layer on the outer surface of the panel with a film thickness of 8 μm or more and 150 μm or less, and the inner surface side to be bonded to the core resin layer has a surface tension of 50 mN / m or more and 1.5 mg / m as measured by JIS K 6768 "Plastics - Films and Sheets - Wetting Tension Test Method".2 More than 130mg / m 2 A steel sheet with a thickness of 0.1 mm or more and a single-sided film-laminated steel sheet with a layer consisting of the following inorganic hydrated oxides and inorganic oxides, or an aluminum sheet with a thickness of 0.24 mm or more and a single-sided film-laminated aluminum sheet, resin The rigid urethane foam resin of the layer has a thickness of 3 mm or more, a dynamic longitudinal modulus measured at 80°C and 1 Hz of 100 MPa or more, and a density of the rigid urethane foam resin after foaming of 0.2 g / cm 3 More than 0.7g / cm 3 The following is a resin-metal composite panel.

[0066] By using the resin-metal laminated panel having the above-mentioned configuration, the surface of the resin-metal laminated panel Material and Core resin It is now possible to provide a stable laminated panel with high adhesive strength between layers, rigidity, and buckling strength at a low cost. [Example]

[0067] The resin metal laminated panel of the present invention will be specifically described with reference to examples. However, the conditions in the examples are merely conditions adopted to confirm the feasibility and effects of the present invention, and the present invention is not limited to the following examples. As long as the object of the present invention is achieved without departing from the gist of the present invention, appropriate modifications may be made within the scope of the purpose. Therefore, the present invention may adopt various conditions, and all of these are included in the technical features of the present invention.

[0068] In the examples and comparative examples, the metal sheet of the one-sided film-laminated steel sheet used as the skin material of the resin-metal composite panel formed by injecting and foaming a rigid urethane resin between two metal sheets as shown in Figure 9 is shown in Table 1, the thermoplastic resin film of the one-sided film-laminated metal sheet is shown in Table 2, and the urethane core of the laminated panel is shown in Table 3. resinThe composition of the layers and the results of the characteristic evaluation of the laminated panel are shown in Table 4 (the appearance and workability evaluation results of the film-laminated steel plate, the film wrinkle degree evaluation results of the film-laminated metal plate and the film cuttability when cutting, the resin film-laminated metal plate peel strength evaluation results of the laminated panel, the impact resistance evaluation results of the laminated panel, the dent resistance evaluation results of the laminated panel, and the high temperature (80°C) panel deflection resistance evaluation test results, and the classification of invention examples and comparative examples).

[0069] [Table 1]

[0070] [Table 2]

[0071] [Table 3]

[0072] [Table 4-1]

[0073] [Table 4-2]

[0074] [Table 4-3]

[0075] [Table 4-4]

[0076] [Table 4-5]

[0077] Specifically, the following applies: The constituent materials of the resin-metal composite panel are shown below.

[0078] [Metal plate] Metal plates M1 to M31 shown in Table 1 were used. M1 to M25 are examples of metal sheets in which the metal sheets are cold-rolled steel sheets, and M1 to M5 are examples of steel sheets on the surface of which a chromium oxide and hydroxide film has been formed by immersion treatment in dichromic acid. M6 to M7 are examples of steel sheets in which a cold-rolled steel sheet has been subjected to cathodic electrolysis in chromic anhydride to form a metallic chromium layer on the surface, and further formed with chromium oxide and hydroxide thereon. M8 to M13 are examples of steel sheets in which cold-rolled steel sheets were subjected to cathodic electrolysis in a Zr fluoride and nitric acid-based treatment solution to generate Zr oxide and Zr hydroxide on the surface. M14 and M15 are examples of steel sheets in which cold-rolled steel sheets were subjected to cathodic electrolysis in a treatment solution containing Ti fluoride and nitric acid to generate Ti oxide and Ti hydroxide on the surface. M16 is an example of a steel sheet in which W oxide and W hydroxide are formed on the surface by immersing the cold-rolled steel sheet in tungstic acid. M17 and M18 are examples of steel sheets that have been subjected to cathodic electrolysis in a nitric acid or Ce treatment solution to produce Ce oxides and Ce hydroxides on the surface. M19 to M22 are examples of steel sheets that have been subjected to a coating type silica treatment to generate SiO2 on the surface. M23 is an example of a steel sheet that is a cold-rolled steel sheet that has been treated with tannic acid. M24 is an example of a cold-rolled steel sheet that has been subjected to a silane coupling treatment. M25 is an example of a metal plate made of SUS304 bright annealed material that has been immersed in dichromic acid. M26 to M29 are examples of metal plates obtained by immersing aluminum plates in dichromate acid. M30 is an example of a cold-rolled steel sheet without chemical conversion treatment.

[0079] [Thermoplastic resin film] Using films F1 to F27 shown in Table 2, resin film laminated metal sheets were produced. F1 to F5 are examples of thermoplastic stretched homo-PET (polyethylene terephthalate resin) films. F6 to F10 are examples of thermoplastic stretched PET-IA (polyethylene terephthalate-isophthalate 8 mol % copolymer resin) films. F11 to F15 are examples of thermoplastic stretched PET-PBT (polyethylene terephthalate-polybutylene terephthalate 50% by mass copolymer resin) films. F16 to F20 are examples of PE (polyethylene) resin films with a thermoplastic unstretched modified resin layer. F21 to F25 are examples of ethylene-propylene copolymer resin films with a thermoplastic unstretched modified resin layer. F26 is an example of a thermoplastic unstretched ionomer resin film. F27 is an example of a thermoplastic unstretched polyvinyl chloride resin film.

[0080] [Urethane core of resin-metal laminated panel resin layer〕 Urethane core of resin-metal laminated panel resin The layers have the components, thickness, density, and dynamic modulus of elasticity at 80°C and 1 Hz shown in Table 3.

[0081] [Resin-metal laminated panel] The resin film shown in Table 2 was thermally laminated onto the metal plate shown in Table 1 to obtain a laminated metal plate, which was cut into 200 mm x 250 mm pieces. These were set on the top and bottom sides of an injection mold, and the urethane raw materials shown in Table 3 were mixed and injected into the injection ports on the sides of the mold within 30 seconds at a pressure of 20 kN / m. 2 After holding the pressure at this level for approximately 30 seconds, the upper and lower molds are opened to form the urethane core shown in Table 3. resin Resin-metal laminated panels having the layer thickness, density, and dynamic modulus of elasticity at 80°C and 1 Hz shown in the left column of Table 4 were obtained.

[0082] [Results of evaluation of resin-metal laminated panel characteristics] The panel property evaluation results of the resin-metal laminated panel obtained above are shown in the right column of Table 4.

[0083] The quality of the resin-metal laminated panel properties was judged by the following method. (1) Determining the degree of film wrinkles on film-laminated metal sheets The degree of wrinkles on the film-laminated metal sheet on the outer surface of the resin-metal laminated panel was judged according to the following criteria. Good: There are wrinkles on the outer surface of the resin-metal laminate panel, but the wrinkles are not so rough that they would catch on your fingernails. Acceptable: Drooping of the film or stringy film debris occurs in the punched and cut areas, but the film does not peel off. Unacceptable: There are film wrinkles on the outer surface of the resin-metal laminate panel that are high enough to catch on a fingernail.

[0084] (2) Cuttability of film on film-laminated steel sheets The film-laminated steel sheet was punched with the film surface facing outward, and a coupon of φ50 mm was punched out using a press, and the cuttability of the film was evaluated. Good: No film sagging, stringy film debris, or film peeling occurs in the punched and cut areas. Acceptable: Drooping of the film or stringy film debris occurs in the punched and cut areas, but the film does not peel off. Acceptable: Core resin When the maximum bubble diameter in the cross-sectional view of the layer is between 300 μm and 500 μm Unacceptable: The film peels off from the punched cut edge.

[0085] (3) Determination of peel strength of resin film laminated metal sheet of laminated panel The resin-metal laminated panel shown in Table 4 was cut with a high-speed precision cutting machine to obtain test pieces measuring 25 mm wide x 150 mm. The resin film laminated metal plates on both sides of the end of the test piece were peeled off by about 30 mm to prepare a gripping portion for clamping in the chuck of the tensile tester. The gripping parts of the resin film laminated metal plate on both sides of the test piece are clamped in the chuck of the tensile testing machine and peeled off 100 mm (movement between chucks: 200 mm) at a pulling speed of 200 mm / min. resinThe peel strength of the laminated metal sheet from the foamed rigid urethane resin was measured. The peel strength measured after peeling 100 mm was evaluated based on the following criteria. Pass was considered fair or better. The results are shown in Tables 3 and 4. Good: 10N / 25mm or less (laminated metal sheet peel strength) Acceptable: 5N / 25mm ≦ (Laminated metal sheet peel strength) < 10N / 25mm Unacceptable: (Laminated metal sheet peel strength) < 5N / 25mm

[0086] (4) Impact resistance assessment of laminated panels For the impact resistance test, a 50mm x 200mm test piece was cut from a resin-metal laminated panel using a high-speed precision cutting machine and placed in a DuPont impact testing machine equipped with a die having a roll-shaped support section with a support point distance of 100mm and a 2.5mm radius at the tip, and a semi-cylindrical punch with a 5mm radius as an impact indenter. A 1kg weight was then dropped from a height of 60mm from the impact receiving surface above the impact indenter, and the test piece was judged to be pass or fail based on whether it buckled. Good: No dents, no buckling, no peeling of the skin Acceptable: slight dent, no buckling, localized peeling of the surface material at the area where the impact indenter hit Unacceptable: Buckling or peeling of the surface material

[0087] (5) Dent resistance assessment of laminated panels A 5cm x 5cm sample was cut from the resin-metal laminated panel using a high-speed precision cutting machine, and a dent impact was applied to the center of the laminated panel sample using a DuPont impact tester (punch tip diameter = 12.5mm, falling weight conditions = 300g x height 40mm). The dent resistance was determined based on the degree of deformation of the labeled metal plate. Good: The diameter of the recess in the resin film laminated metal sheet on the surface of the panel sample is less than 2 mm. Acceptable: The diameter of the recess in the resin film laminated metal sheet on the surface of the panel sample is 2mm or more and less than 5mm. Unacceptable: The diameter of the recess in the resin film laminated metal sheet on the surface of the panel sample exceeds 5 mm.

[0088] (6) High temperature (80℃) panel deflection resistance evaluation The panel's resistance to deflection was evaluated by measuring the bending stiffness of the stroke-load diagram in a three-point bending test. Resin-metal composite panel specimens, 50 mm wide and 200 mm long, were cut with a high-speed precision cutter and placed in a tensile testing machine equipped with a thermostatic chamber. The specimens were compressed at a distance of 100 mm between support points, using a semi-cylindrical punch with a 25 mm tip diameter at a punch stroke rate of 50 mm / min. The bending stiffness was measured by determining the slope of the linear portion of the elastic deformation region of the stroke-load diagram. The test was conducted at room temperature and 80°C in the thermostatic chamber. The specimens were placed on the three-point bending test fixture and the test was conducted 10 minutes after the thermostatic chamber temperature reached the specified temperature. Good: The bending rigidity of the panel at 80°C is 80% or more of the bending rigidity at room temperature Acceptable: The bending rigidity of the panel at 80°C is 50% or more but less than 80% of the bending rigidity at room temperature. Unacceptable: The bending stiffness of the panel at 80°C is less than 50% of the bending stiffness at room temperature.

[0089] As is clear from Table 4, the resin-metal composite panel having the configuration of the present invention exhibits excellent panel characteristics. [Industrial Applicability]

[0090] The resin-metal laminated panel of the present invention is a core of a laminated panel. resin In addition to the high adhesive strength between layers and the high panel rigidity, the laminated panel can be produced inexpensively, making it extremely useful as a lightweight laminated panel for building materials, ships, and vehicle floor and wall materials.

Claims

1. The skin material is two single-sided resin film laminated metal sheets having a thermoplastic resin layer with a film thickness of 8 μm or more and 150 μm or less on one surface of a metal sheet made of a steel sheet or an aluminum sheet, The side with the thermoplastic resin layer is the outer surface of the resin-metal composite panel, a layer comprising an inorganic hydrated oxide and an inorganic oxide, the layer having a surface tension of 50 mN / m or more as measured in accordance with JIS K 6768 "Plastics - Films and Sheets - Wet Tension Test Method" and containing 1.5 mg / m or more and 130 mg / m or less, on the side of the skin material where there is no thermoplastic resin layer; A resin-metal composite panel characterized in that a core resin layer is injected between the two layers of inorganic hydrated oxide and inorganic oxide of the skin material, the core resin layer being a rigid foamed urethane resin having a thickness of 3 mm or more, a dynamic longitudinal modulus of elasticity of 100 MPa or more measured at 80°C and 1 Hz, and a density after foaming of 0.2 g / cm3 or more and 0.7 g / cm3 or less.

2. The resin-metal composite panel according to claim 1, characterized in that the inorganic hydrated oxides and inorganic oxides on the skin material are layers consisting of inorganic hydrated oxides and inorganic oxides containing one or more types selected from chromium hydrated oxide, zirconium hydrated oxide, titanium hydrated oxide, tungsten hydrated oxide, cerium hydrated oxide, and silica.

3. A resin-metal composite panel as described in claim 1 or claim 2, characterized in that a thermoplastic film having a surface tension of 40 mN / m or more is heat-fused to the outer surface of the resin-metal composite panel of the one-sided resin film laminated metal plate.

4. A resin-metal composite panel as described in Claim 3, characterized in that the film is a resin blend of one or more types selected from thermoplastic polyester resin, polyethylene resin with a modified resin layer, polypropylene resin with a modified resin layer, ethylene-propylene copolymer resin with a modified resin layer, ionomer resin, and polyvinyl chloride resin.

Images