JPH0466692B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a composite plate formed by bonding a polymer layer between two metal plates, and a method for manufacturing the same, and particularly relates to a composite plate formed by bonding a polymer layer between two metal plates. The present invention relates to a composite plate that suppresses the above and a method for continuously manufacturing the same. BACKGROUND OF THE INVENTION Composite plates in which a synthetic resin such as polyolefin is bonded as a core material between two metal plates such as aluminum, iron, or stainless steel are well known. (For example, Japanese Patent Publication No. 39-4739). This composite board has various features such as being lightweight, workable, and has excellent impact resistance, and is used for building materials, interior and exterior materials, and other applications. Improvements continue to be considered. One of the improvements is a composite plate in which the front and back sides of the metal plate are made of different metals. Problems to be Solved by the Invention However, when different types of metal plates are used, each metal has its own coefficient of thermal expansion, so there is a difference in expansion coefficient between the front and back sides.
"Warpage" that does not occur with conventional composite boards that use
The problem arises. This "warping" occurs even when manufacturing composite boards according to conventional methods, but even if you can make them smooth immediately after manufacturing by some method, "warping" will occur when subjected to thermal history, even at room temperature. Since it cannot be returned to a flat surface, it has been desired to solve this problem before putting composite plates using different metal plates into practical use. The present inventors conducted various studies in view of the problem of "warping" of composite plates using dissimilar metals, and found that using an elastomer as a core material improves the above problem, but the resulting composite material is inferior in rigidity. I learned that. The present invention has been made based on this knowledge with the aim of obtaining a composite board that has performance equivalent to or better than conventional composite boards and that has suppressed "warpage". Means for Solving the Problems The present invention involves bonding a specific polymer layer between the metal plates and bonding each layer with a specific thickness when obtaining a composite plate using two dissimilar metal plates. Thus, a composite plate is obtained in which the above-mentioned problems are solved. That is, the gist of the present invention is to provide a composite plate formed by bonding a polymer layer between two metal plates, in which the two metal plates have a total thickness of 0.1 to 1.0 mm, and each plate is made of different metals. The polymer layer is a thermoplastic synthetic resin layer selected from polyethylene or polypropylene and has a thickness of 0.05 to 3 mm.
The composite plate is made of a thermoplastic elastomer layer based on ethylene-propylene copolymer that is compatible with the thermoplastic synthetic resin, and the thickness of the composite plate is 0.5 to 6 mm.
The present invention resides in a dissimilar metal composite plate characterized by the following. Furthermore, the gist of the present invention resides in a method for producing the above-mentioned composite plate by hot-pressing a polymer layer between two dissimilar metal plates. The present invention will be explained in detail below. Examples of the metal plate used in the present invention include metals such as aluminum, iron, copper, tin, and nickel, or alloys thereof, particularly two types of metal plates selected from the three types of aluminum, iron, and stainless steel. The thickness of the metal plate is usually 0.05 to 0.5 mm, but is not limited to this, and the total thickness of the two metal plates is
It is also possible to make the two sheets have different thicknesses as long as they are 0.1 to 1.0 mm. In addition, the ratio of the linear expansion coefficients of two metal plates is 1.05 to 3.0, and even 1.1 to 2.5.
It is particularly effective in the present invention to use the following. Further, as the thermoplastic synthetic resin selected from polyethylene or polypropylene (hereinafter simply referred to as "synthetic resin") constituting the polymer layer, any resin used in ordinary extrusion molding can be used as appropriate. The thickness of the synthetic resin can be selected as appropriate, but is usually about 0.5 to 5.5 mm. A major feature of the present invention is that the polymer layer contains not only a synthetic resin layer but also an ethylene-propylene copolymer-based thermoplastic elastomer (hereinafter abbreviated as "elastomer") layer. The elastomer may be any material as long as it has rubber elasticity and is compatible with the synthetic resin used, and has a tensile strength of 50 kg/cm ² or more at the operating temperature,
Preferably, the elongation is 100% or more. Amorphous ethylene-propylene copolymers are particularly suitable as such elastomers. The thickness of the elastomer layer is 0.05 to 3 mm, more preferably 0.1 to 2 mm.
If the elastomer layer is too thin, warping of the composite plate will increase, and if it is too thick, the rigidity of the composite plate will decrease, which is undesirable. The composite plate of the present invention consists of these metal plates, synthetic resin layers, and elastomer layers, and has a total thickness of 0.5
~6 mm, furthermore 0.5~4 mm. If this thickness is smaller than the above range, it will be difficult to suppress the warping of the composite plate, and if it is larger than the above range, the warp will be suppressed even with the synthetic resin alone without using an elastomer layer, making it unnecessary to use the composite board of the present invention. Note that the thickness of the metal plate and the elastomer layer is within the above-mentioned range, but when actually obtaining a composite plate, the present invention is based on the fact that as the thickness of the metal plate and composite plate increases, the required amount of elastomer decreases. The thickness of each layer was determined by taking this into consideration,
It is preferable to determine the thickness of the remaining synthetic resin layer accordingly. In addition, in the case where each layer is divided into a plurality of parts, the thickness of the synthetic resin layer and the elastomer layer in the present invention is the total thickness of the parts. The metal plate and the polymer layer are bonded together such that the polymer layer is interposed between the two metal plates to obtain a composite plate. The layer structure of the composite board will be explained with reference to the drawings.
Figures 1 to 3 are explanatory diagrams showing the layer structure of the composite plate, where 1 and 4 are metal plates (1 and 4 are different metals), 2 and 2' are synthetic resin layers, and 3 and 4 are metal plates (1 and 4 are different metals). 3' represents the elastomer layer. The arrangement of the synthetic resin layer and the elastomer layer in the polymer layer is not particularly limited.
In addition to simply bonding the synthetic resin layer and elastomer layer one by one as shown in Figure 1,
It is also possible to divide each layer into a plurality of layers and laminate them as shown in the figure, as long as the total thickness of the elastomer layers is within the above range. In particular, in order to efficiently control the warpage of the obtained composite plate using a smaller amount of elastomer, the structure shown in FIG. 2 in which synthetic resin layers are bonded to both sides of the elastomer layer is suitable. In this case, the thickness of each synthetic resin layer can be appropriately selected depending on the metal on both sides, but the thickness ratio is usually in the range of 1:0.3 to 3, and each synthetic resin layer can be made of the same or different types. But it's okay. It should be noted that the above-mentioned composite material can be used to add a filler to the synthetic resin layer and the elastomer layer, and to perform various treatments such as film treatment on the surface of the composite plate. The metal plate and the polymer layer can be joined by conventionally known methods including a continuous method and a batch method, and thermocompression bonding is preferable from the viewpoint of production. An example of a manufacturing method is to continuously supply two metal plates coated with a synthetic resin in advance and a molten elastomer, or a metal plate and a molten synthetic resin and elastomer between heated pressure rollers. Examples include a method in which metal plates are bonded under heat and pressure on both sides of a polymer layer formed into a film. A preferred method is to supply a laminated layer of synthetic resin and bond it under heat and pressure. At the time of bonding, an adhesive may be used to bond each layer, and an adhesive layer may be included. However, since the synthetic resin layer and elastomer layer of the present invention are compatible, these two layers may be No adhesive is usually used in between. An example of manufacturing a composite plate based on the method of the present invention will be described below. The two metal sheets in a stretched state are subjected to necessary surface treatments such as degreasing, washing, and drying according to conventionally known methods, and are preheated to a temperature close to the heat-pressing temperature described below. The preheated metal sheet is extruded from an extruder, and together with the elastomer, both of which are in a molten state, and the synthetic resin above and below the elastomer, the sheet is fed between heated pressure rollers and bonded together. The temperature at the time of lamination is determined by considering the wettability with the resin, elastomer, and metal used, and is preferably selected from a range of approximately 150 to 250°C. The composite plate obtained from the hot pressure roller is heated and aged as necessary, and then cooled until the polymer sheet reaches a melting temperature or lower to obtain a composite plate according to the present invention. Effects The present invention can provide an excellent composite plate using two types of metal plates with the above configuration, and can easily manufacture the composite plate. Effects of the Invention According to the present invention, it is possible to supply a composite plate in which "warpage" is suppressed even during manufacturing and after being subjected to temperature changes, even when the composite plate uses different metal plates, and
The composite board also has the characteristics of conventional composite boards, such as lightness, workability, rigidity, impact resistance, and sound and vibration damping properties, and the composite board according to the present invention is extremely useful. Furthermore, the method of the present invention enables continuous production of such excellent composite plates, and has extremely great industrial significance. EXAMPLES The present invention will be explained in more detail with reference to Examples below. Examples 1 to 7, Comparative Examples 1 to 5 Stainless steel plates (SUB304, thickness 0.15 mm), steel plates (TFS and cold rolled steel plates, both thickness 0.2 mm), which were subjected to surface treatment as necessary as metal plates, and An aluminum plate (thickness: 0.15 mm) is used, and the synthetic resin layer is made of high-density polyethylene (MI: 0.2, density:
0.95) or polypropylene (MFI: 0.5, density
0.91) sheet, ethylene-propylene copolymer (MI: 1.9, density: 0.86) as elastomer layer
or the polymer and low density polyethylene (MI:
1.8, density: 0.91) using a sheet of the mixture in equal amounts, each layer was heat-pressed using a press to obtain a composite plate with a thickness of 1 mm having the structure shown in Table 1. Table 1 shows the results of measuring the warpage reduction rate and rigidity ratio of the composite plate obtained. In addition, the warpage reduction rate is
A sample of 220 mm x 220 mm was cut out from each composite plate, placed on a flat plate, and the maximum value of warp on each four sides was measured and the average value was calculated. ,4) Warpage reduction rate 0
%, a complete flat plate is expressed as a warpage reduction rate of 100%. In addition, the rigidity ratio was determined by cutting a 20 mm x 220 mm sample from a composite plate, placing a weight with a load of 500 g on the center with a two-point support span of 200 mm, and measuring the amount of deflection at that time. , 3, 4) was calculated by setting the amount of deflection to 1, and expressed as a stiffness ratio. Therefore, the smaller the value of the stiffness ratio, the higher the stiffness.

[Table] Example 8 and Comparative Example 6 A stainless steel plate (SUS304) with a width of 650 mm and a thickness of 0.15 mm and a steel plate (TFS) with a width of 650 mm and a thickness of 0.2 mm were heated to the pressure roller temperature using a preheating heater while applying constant tension. The temperature rose gradually. Also,
High-density polyethylene (MI: 0.2,
Density: 0.95), ethylene-propylene copolymer (MI: 1.9, density 0.86) was used as the elastomer, and the extrusion amount of each layer was adjusted so that the thickness of the elastomer layer was 0.1 mm. A three-layer polymer molten sheet of synthetic resin was extruded and bonded by being supplied between pressure rollers adjusted to a distance of about 1 mm so as to be interposed between the preheated stainless steel plate and the steel plate. After that, it is cooled to room temperature and the thickness of each synthetic resin layer is
A composite plate with a thickness of 0.275 mm and an elastomer layer of 0.1 mm was obtained. (Example 8) A composite plate was also obtained in the same manner as described above, except that a molten sheet of only high-density polyethylene without using an elastomer was used instead of the 3-layer polymer molten sheet. (Comparative Example 6) Table 2 shows the results of measuring the warpage reduction rate and rigidity ratio of the obtained composite plate. In addition, the warpage reduction rate is
A sample of 600 mm x 600 mm was cut out from each composite plate and measured in the same manner as in Examples 1 to 7, and the warpage reduction rate of the composite plate of Comparative Example 6 was expressed as 0%. In addition, the rigidity ratio was determined by cutting out a 100 mm x 600 mm sample from a composite board, supporting it at two points, and setting one point in the center with a span of 500 mm.
A load of Kg was applied, the amount of deflection at that time was measured, the amount of deflection of the composite plate of Comparative Example 6 was set as 1, and the result was converted and expressed as a rigidity ratio.

【table】 [Brief explanation of drawings]

FIGS. 1 to 3 are explanatory diagrams showing the layer structure of the dissimilar metal composite plate of the present invention. The drawing code is 1
and 4 are metal plates (1 and 4 are different metals), 2 and 2' are synthetic resin layers, and 3 and 3' are elastomer layers.

Claims (1)

[Claims] 1. A composite plate formed by bonding a polymer layer between two metal plates, wherein the two metal plates have a total thickness of 0.1 to 1.0 mm and are each made of different metals. It is a metal plate, and the polymer layer is composed of a thermoplastic synthetic resin layer selected from polyethylene or polypropylene, and an ethylene-propylene copolymer thermoplastic elastomer layer having a thickness of 0.05 to 3 mm and having compatibility with the thermoplastic synthetic resin, A dissimilar metal composite plate characterized in that the thickness of the composite plate is 0.5 to 6 mm. 2. The dissimilar metal composite plate according to claim 1, wherein the polymer layer is formed by bonding thermoplastic synthetic resin layers to both sides of a thermoplastic elastomer layer. 3. A method for producing a dissimilar metal composite plate having a thickness of 0.5 to 6 mm in which a polymer layer is heat-pressed between two dissimilar metal plates, wherein the polymer layer is a thermoplastic synthetic resin layer selected from polyethylene or polypropylene, and the thermoplastic synthetic resin layer is selected from polyethylene or polypropylene. The composite plate is composed of a thermoplastic elastomer layer made of ethylene-propylene copolymer that is compatible with the resin, and the total thickness of the two metal plates in the obtained composite plate is 0.1 to 1.0 mm, and the thickness of the thermoplastic elastomer layer is A method for manufacturing a dissimilar metal composite plate, characterized in that the thickness is 0.05 to 3 mm.