JPH0563306B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing a laminated metal plate having excellent corrosion resistance and adhesion by low-temperature preheating. (Prior art) Conventionally, when manufacturing a laminated metal plate with excellent corrosion resistance and adhesion, when continuously coating the surface of the metal plate with resin, a preheated metal plate was melt-kneaded using an extruder. A method of extruding thermoplastic resin through a T-die is known (Japanese Patent Application Laid-Open No. 1983-1999).
Publication No. 203545). FIG. 2 shows a method for producing a laminated metal plate specifically disclosed in Japanese Patent Application Laid-Open No. 57-203545, in which the laminated metal plate is wound around a heating roll 9, wound around a cooling roll 10, and The melted thermoplastic resin 6 is flowed down from the T-die 5 through the extruder 4 onto the interface between the preheated surface of the metal plate 3 which has been pressure-welded by the cooling roll 10 and the cooling roll 10, and the metal plate 3 is continuously coated with thermoplastic resin 6. The resin-coated metal plate (laminated metal plate) 8 is wound up through a cooling device (not shown) such as a water cooling tank or a cooling roll downstream of the roll 10. Also known is a method for manufacturing a laminated metal plate in which the heating roll 9 is a normal nip roll, and a preheating device such as an induction heating type or a gas heating type is disposed upstream of the nip roll to preheat the metal. Note that the cooling roll 10 is usually a water-cooled roll made of metal such as iron or copper, which is inexpensive, has good thermal conductivity, and has good cooling performance.Furthermore, the surface in contact with the resin is mirror-finished to improve the surface condition of the resin. In order to improve the performance, the metal water-cooled rolls whose surfaces are plated with hard chrome are also used. Further, as the nip roll, a nip roll made of rubber such as silicone rubber, chloroprene rubber, or polytetrafluoroethylene rubber, which has good pressure bonding properties and heat resistance, is usually used. (Problem to be Solved by the Invention) When manufacturing a laminated metal plate using such a conventional method, the preheating temperature of the metal plate is increased to coat the metal plate with resin, and then the temperature at which it can be rolled up using the cooling device described above is increased. In order to improve adhesion, it is necessary to maintain the temperature as high as possible until it is forcedly cooled to room temperature, for example. On the other hand, from an energy cost perspective, it is best to manufacture laminated metal plates with excellent adhesion through low-temperature preheating, but in the conventional method, the resin-coated metal plate is cooled by a cooling roll immediately after resin coating. Therefore, if the preheating temperature is low, the temperature of the metal plate will be low until it is forcibly cooled by the cooling device, making it impossible to produce laminated metal plates with excellent adhesion. There is. The present invention provides a method for producing a laminated metal plate that can produce a laminated metal plate with excellent performance (corrosion resistance, adhesion) by low-temperature preheating. (Means for Solving the Problems) The gist of the present invention is as follows. After preheating the metal plate, the metal plate is placed between the nip roll and the non-cooled or heated roll, without being wrapped around the nip roll, and wound around the non-cooled or heated roll, and between the nip roll and the metal plate via an extruder. The molten thermoplastic resin is flowed down from the die and the resin is laminated on the metal plate with the above-mentioned Nippro roll, and the laminated metal plate after lamination is not wrapped around the above-mentioned Nippro roll, but is wound around the above-mentioned non-cooled or heated roll. A method for manufacturing a laminated metal plate, characterized by passing through the laminated metal plate. In the present invention, the metal plate includes a steel plate (including foil),
Any of the following surface treatments on the surface of aluminum plates (including foils) or these metal plates: Sn, Zn, Al, Pb, Ni, Cr, or Cu plating. Composite plating of two or more of the above metals. Alloy plating containing one or more of the metals listed above Composite plating containing one or more of the metals listed above as a main component. Salt-treated products can also be used. The thermoplastic resin used for coating in the present invention is typically polyester resin, polyolefin resin, vinyl chloride resin, polycarbonate resin, or the like. The present invention will be explained in detail below. As shown in FIG. 1, a metal plate 3 preheated by a preheating device (not shown) is wound around an uncooled or heated roll 1 made of metal, rubber, etc. A nip roll 2 made of rubber such as silicone rubber, chloroprene rubber, polytetrafluoroethylene rubber, etc. is pressed onto the nip roll 2, and a molten thermoplastic is applied to the interface between the surface of the metal plate 3 and the nip roll 2 through an extruder 4 and a T-die 5. The resin 6 is flowed down and laminated onto the metal plate 3, and then cooled to room temperature, for example, in a cooling device 7 provided with, for example, a water spray nozzle downstream of the roll 1, to obtain a laminated metal plate 8. According to the method of the present invention, since the laminated metal plate 8 is uncooled or wrapped around the heating roll 1, the amount of temperature drop due to roll wrapping is significantly reduced compared to the conventional method in which the laminated metal plate 8 is wrapped around the cooling roll 10. After being coated with the resin, the temperature of the laminated metal plate 8 until it is forcedly cooled (hereinafter referred to as the heat retention temperature of the laminated metal plate) becomes significantly high. As mentioned earlier, if the preheating temperature of the metal plate 3 is low and the heat retention temperature of the laminated metal plate is low, excellent adhesion cannot be obtained. In the conventional method, the temperature drop due to roll wrapping is large, so it is necessary to significantly increase the preheating temperature of the metal plate, but in the method of the present invention, the temperature drop due to roll wrapping is small, so it is not necessary to increase the preheating temperature as much as in the conventional method. do not have.
That is, according to the rod of the present invention, the preheating temperature required to ensure a heat retention temperature that provides excellent adhesion can be significantly lowered compared to the conventional method. In the example of the manufacturing apparatus for laminated metal plates shown in FIG. 1, a rubber nip roll is used as the nip roll 2, but since the preheated metal plate 3 is not wrapped around the nip roll 2, for example, iron, copper, etc. Even if a metal water-cooled roll is used, the above effects can be obtained. Further, in the above example of the device, in order to shorten the cooling line length, a water spray type cooling device 7 is provided to cool the laminated metal plate 8 to room temperature, but if there is no restriction on the line length, It may be configured to cool by natural cooling. Further, in the above manufacturing apparatus example, only the thermoplastic resin flows down from the T-die, but the thermoplastic resin and the adhesive thermoplastic resin may be co-extruded using two extruders. (Example) Example 1 A laminated metal plate manufacturing apparatus was used in which a non-cooled rubber roll with an outer diameter of 450 mm was used as the non-cooled roll 1 in FIG. 1, and a silicone rubber nip roll with an outer diameter of 300 mm was used as the nip roll 2. do,
An electrolytic chromic acid treated steel plate with a thickness of 0.2 mm is used as the metal plate 3. After preheating this steel plate to 230°C, polyethylene terephthalate is melted and extruded from a T-die through an extruder to the interface between the surface of the steel plate and the Nipro roll. did. The temperature of the molten resin is 280℃, the coating thickness is 50μm, and the line speed is 50m/
min, and after pressure welding, the steel plate is rolled 1
The angle at which it is wrapped is 90°. Furthermore, the laminated steel plate reached the cooling device 7 downstream of the uncooled roll 1 in 3 seconds after being pressed, was cooled to room temperature by water spray, dried, and then wound up to obtain a laminated steel plate. Example 2 A laminated steel plate was manufactured by using an uncooled iron roll having an outer diameter of 450 mm as the uncooled roll 1 shown in FIG. 1, and otherwise operating under the same conditions as in Example 1. Example 3 A laminated steel plate was manufactured by using the heating roll 1 shown in FIG. 1 with an outer diameter of 450 mm, and otherwise operating under the same conditions as in Example 1. In order to compensate for natural cooling in the heating roll, the surface temperature of the heating roll was set at a temperature 20°C higher than the steel plate preheating temperature. Conventional Example 1 A laminated metal plate manufacturing apparatus was used, in which the heating roll 9 shown in Fig. 2 had an outer diameter of 300 mm, and the cooling roll 10 had an outer diameter of 450 mm and a hard chrome-plated iron water-cooled roll. Similarly, a 0.2 mm electrolytic chromic acid treated steel plate was heated to 230°C.
After preheating, the temperature of the molten resin was 280℃, the coating thickness was 50μm, the line speed was 50m/min, and the steel plate was wound around a water-cooled roll at an angle of 90℃.
Polyethylene terephthalate is melted and extruded from a T-die through an extruder onto the interface between the steel plate surface and the water-cooled roll, and is laminated. 3 seconds after pressure welding, it reaches the cooling device downstream of the water-cooled roll 10 and is sprayed with water. It was cooled to room temperature, dried, and then rolled up to obtain a laminated steel plate. Conventional Example 2 The heating roll 9 in Fig. 2 is a nip roll, and the outside diameter of the nip roll used in the above embodiment is
A laminated steel plate was manufactured using a 300 mm silicone rubber nip roll under the same conditions as in the conventional example. Examples 4, 5, and 6 Laminated steel plates were manufactured by changing the preheating temperature of Examples 1, 2, and 3 to 200°C. Conventional Examples 3 and 4 Laminated steel plates were manufactured by changing the preheating temperature of Conventional Examples 1 and 2 to 200°C. Examples 7, 8, and 9 Laminated steel plates were manufactured by changing the preheating temperature of Examples 1, 2, and 3 to 170°C. Conventional Examples 5 and 6 Laminated steel plates were manufactured by changing the preheating temperature of Conventional Examples 1 and 2 to 170°C. Performance tests were conducted on the laminated steel plates obtained in the above examples and conventional examples as follows. Adhesion...180℃ peel test (tensile speed: 100
mm/min) Corrosion resistance: Sprayed with 5% saline at 35°C for 1500 hours The results were evaluated in 5 stages according to the following criteria. 5...Very good, 3...Good, 1...Poor The performance evaluation results are shown in Table 1 together with roll conditions, preheating temperature, and average temperature (heat retention temperature) after pressure lamination until forced cooling. In addition, when only the rubber nip roll 2 of Examples 1 to 9 was changed to an iron water-cooled roll with an outer diameter of 300 mm and laminated steel plates were manufactured and the adhesion and corrosion resistance were investigated, the results showed that Examples 1 to 9 shown in Table 1 Equivalent adhesion and corrosion resistance were obtained. The heat retention temperature during production was also the same as that of Examples 1 to 9 shown in Table 1. From Table 1, it is clear that according to the method of the present invention, a laminated steel sheet with superior adhesion and corrosion resistance can be obtained with lower temperature preheating than the conventional method.

[Table] (Effects of the Invention) As detailed above, according to the method of the present invention, a laminated metal plate having excellent corrosion resistance and adhesion can be produced by low-temperature preheating.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the method of the present invention, and FIG. 2 is an explanatory diagram of the conventional method. 1...Non-cooled or heated roll, 2...Nippro roll, 3...Metal plate, 4...Extruder, 5...T die, 6
...Thermoplastic resin, 7... Cooling device, 8... Laminated metal plate, 9... Heating roll, 10... Cooling roll.

Claims (1)

[Claims] 1. After preheating the metal plate, wrap it between the nip roll and the non-cooled or heated roll without wrapping it around the nip roll, and wrap it around the non-cooled or heated roll, and between the nip roll and the metal plate.
After passing through the extruder, the molten thermoplastic resin is flowed down from the T-die and the resin is laminated onto the metal plate using the above Nip roll, and the laminated metal plate after lamination is not wrapped around the above Nip roll, but is placed on the non-cooled or heated roll. A method for manufacturing a laminated metal sheet, which comprises winding the sheet and passing it through uncooled or heated rolls.