JPH04325251A - Manufacture of laminated metal plate - Google Patents

Abstract

PURPOSE:To improve corrosion resistance, adhesive properties and yield by making the width of a thermoplastic resin film flowing down on the interfaces of a metal plate and nip rolls larger than that of the metal plate and covering the metal plate and a heating roll with the resin film while previously forming an oil film on the surface of the heating roll. CONSTITUTION:A metal plate 3 discharged from a supply reel 11 is wound on a non-cooling or heating roll 1 through a preheater 12 and a turn-down roll 13. A nip roll 2 is pressure-welded to the metal plate 3 while a thermoplastic resin film 6 under a molten state through a T die 5 from an extruder is supplied on these interfaces. A metal plate 8, on which the resin film 6 is laminated, is wound on a take-up reel 14 through a cooler 7. An oil-film forming device 15 is mounted adjacently to the winding section of the roll 1 in said device. On the other hand, the T die 5 constitutes the width of the resin film 6 in an adjustable manner. The width of the resin film 6 is made larger than that of the metal plate 3, thus covering the metal plate 3 and the roll 1 with the resin film 6.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing laminated metal plates having excellent corrosion resistance and adhesion with a high yield.

0002

[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 a thermoplastic resin from a T-die is known (Japanese Patent Application Laid-Open No. 57-203545).

FIG. 4 shows a method for manufacturing 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 A T-die 5 is inserted into the interface between the cooling roll 10 and the surface of the preheated metal plate 3 which is pressed by the heating roll 9 and the cooling roll 10 through the extruder 4.
A mode is shown in which the metal plate 3 is continuously coated with the thermoplastic resin 6 by flowing down the more molten 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 cooling roll 10.

There is also 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 plate. Are known. Note that the cooling roll 10 is usually an internal 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, so that the surface condition of the resin can be adjusted. In order to improve the quality, the surface of the metal internal water-cooled roll is plated with hard chrome.

[0005] As the nip roll, a rubber-lined nip roll is usually used in which a metal roll body is lined with silicone rubber, chloroprene rubber, polytetrafluoroethylene rubber, etc., which have good pressure bonding properties and heat resistance. When manufacturing a laminated metal plate using such a conventional method, the preheating temperature of the metal plate is raised to coat the metal plate with resin, and then the resin is forcibly cooled to a temperature at which it can be rolled, such as room temperature, using the cooling device. In order to improve adhesion, it is necessary to maintain the temperature as high as possible.

On the other hand, from an energy cost perspective, it is best to produce a laminated metal plate with excellent adhesion by preheating at a low temperature. Since it is designed to be cooled, 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 manufacture laminated metal plates with excellent adhesion. There is a problem.

In order to solve these problems, the present inventors proposed the following method in Japanese Patent Application No. 1-64434. As shown in FIG. 5, the method described in Japanese Patent Application No. 1-64434 (referred to as the "first-to-file method") is to place a metal plate 3 preheated by a preheating device (not shown) into a metal roll body or a metal roll body with rubber or the like. wrapped around a lined uncooled or heated roll 1,
A rubber-lined nip roll 2, in which a metal roll body is lined with silicone rubber, chloroprene rubber, polytetrafluoroethylene rubber, etc., is pressed against the metal plate 3 wound around the roll 1, and the surface of the metal plate 3 and the nip roll 2 are pressed together. The molten thermoplastic resin 6 flows down from the T-die 5 through the extruder 4 to the interface and is laminated onto the metal plate 3.
For example, the laminated metal plate 8 is obtained by cooling to room temperature, for example, in a cooling device 7 provided with a water spray nozzle, a gas jet nozzle, etc. downstream of the roll 1.

According to the method of the prior application, since the laminated metal plate 8 is wrapped around the uncooled or heated roll 1, the amount of temperature drop due to roll wrapping is significantly reduced compared to the conventional method where the laminated metal plate 8 is wrapped around the cooling roll 10. , the temperature of the laminated metal plate 8 after being coated with resin until it is forcedly cooled (
The heat retention temperature of the laminated metal plate (hereinafter referred to as the heat retention temperature) becomes significantly higher. As mentioned earlier, the preheating temperature of the metal plate 3 is low,
Excellent adhesion cannot be obtained if the heat retention temperature of the laminated metal plate is low, so in order to ensure the heat retention temperature to obtain excellent adhesion, conventional methods require a large temperature drop due to roll wrapping. Although it is necessary to greatly increase the preheating temperature of the metal plate, in the method of the prior application, the temperature decrease due to roll wrapping is small, so there is no need to increase the preheating temperature as much as in the conventional method. That is, according to the method of the prior application, 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 laminated metal plate manufacturing apparatus shown in FIG. 5, a rubber-lined nip roll is used as the nip roll 2, but since the preheated metal plate 3 is not wound around the nip roll 2, for example, iron, Even if an internal water-cooled roll made of metal such as copper is employed, the above effects can be obtained. In addition, in the above device example, in order to shorten the cooling line length, a cooling device 7 having a water spray nozzle, a gas jet nozzle, etc. is provided to cool the laminated metal plate 8 to room temperature. If there are no restrictions, the cooling may be performed by natural cooling.

[0010] 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. As a metal plate, a steel plate (including foil), an aluminum plate (including foil), or one of the following surface treatments on the surface of these metal plates, namely: Sn, Zn, Al, Pb, Ni, Cr or Cu. Plating ■ Composite plating of two or more metals shown in ■ above ■ Alloy plating containing one or more of the metals shown in ■ above ■ Composite plating containing one or more of the metals shown in ■ above as main components, etc. Furthermore, the metal plate treated with chromate or phosphate can also be used.

Typical thermoplastic resins used for the coating include polyester resin, polyolefin resin, vinyl chloride resin, and polycarbonate resin.

0012

[Problems to be Solved by the Invention] As is well known, the molten thermoplastic resin film flowing down from the slit-shaped opening of a T-die becomes narrower (neck-in) as it flows down from the opening. The resin flow rate per unit width in the width direction of the thermoplastic resin film is uniform at the center, but larger at both ends than at the center.

Therefore, in the prior application method, the width of the thermoplastic resin film flowing down near the interface between the metal plate and the nip roll is
If the width is equal to the width of the metal plate that is uncooled or wound around a heated roll, the thickness of the coating resin in the width direction of the obtained laminated metal plate will be uneven, and the thickness of the coating resin will be uneven at both ends in the width direction where the thickness of the coating resin is uneven. There is a problem in that the part does not become a product, and that part must be trimmed in a post-process, resulting in a significant drop in product yield. Of course, if the width of the thermoplastic resin film is made narrower than the width of the metal plate,
Since both ends that are not covered with resin are not part of the product,
Furthermore, product yield is reduced.

On the other hand, in order to obtain a laminated metal plate with a uniform coating resin thickness in the width direction and to increase product yield, the width of the thermoplastic resin film flowing down near the interface between the metal plate and the nip roll is heated or uncooled. When covering the metal plate at the center of the thermoplastic resin film, which has a width larger than the width of the metal plate that passes through the roll and has an equal resin flow rate per unit width, the thermoplastic resin film at both ends The resin film coats the surface of the uncooled or heated roll, which has a relatively high temperature, and adheres relatively firmly to the roll surface, so that when the resin-coated metal plate is separated from the uncooled or heated roll. It is said that the resin film that is relatively firmly attached to the surface of the non-cooled or heated roll is torn off from the resin film that is coated on the metal plate, and becomes wrapped around the non-cooled or heated roll, making it impossible to operate. There is a problem.

The present invention solves these problems and provides a method for manufacturing a laminated metal plate having excellent corrosion resistance and adhesion with a high yield.

[0016]

[Means for Solving the Problems] The gist of the present invention is as follows. Uncooled or wrapped around heated rolls,
Lamination in which a nip roll is pressed against a preheated metal plate, and a molten thermoplastic resin film is flowed down from a T-die through an extruder near the interface between the nip roll and the metal plate to coat the metal plate with the thermoplastic resin film. In the method of manufacturing a metal plate,
The width of the thermoplastic resin film flowing down near the interface between the metal plate and the nip roll is made larger than the width of the metal plate, so that the center part in the width direction of the thermoplastic resin film covers the entire width of the metal plate, and A method for producing a laminated metal plate, which comprises forming an oil film in advance on the surface area of an uncooled or heated roll that is covered by both ends in the width direction of a thermoplastic resin film.

[0017] As a method for forming the oil film, existing techniques such as a rubbing method using an oil-impregnated pad, a spray method, an electrostatic coating method, etc. can be employed. In addition, as a method for forming an oil film on the surface area of the uncooled or heated roll covered by both ends of the thermoplastic resin film in the width direction, there is a method using the existing technology described above. A method in which an oil film is formed only on the surface area of the uncooled or heated roll, (2) a method in which an oil film is formed in a slightly wider area than the above surface area, and (2) a method in which an oil film is formed over the entire surface area of the above roll, etc. can be adopted. . In the above methods (1) and (2) in which an oil film is widely formed on the metal plate side, the oil film is transferred to the non-resin coated surface of the metal plate.

Furthermore, when an oil film is transferred to the non-resin coated surface of the metal plate as described above, the type of oil forming the oil film may be selected depending on the use of the laminated metal plate.
For example, if the main use of laminated metal plates is food containers, electric tinplates that are permitted under the Food Sanitation Act and have characteristics such as corrosion resistance, paint adhesion, and smudgeability when used as food containers are used. It is necessary to use the oil used for surface-treated steel sheets for food containers such as the above, and cottonseed oil, DOS oil, ATBS oil, etc. are most suitable as oil types.

[0019]

[Operation] The method of the present invention makes the width of the thermoplastic resin film flowing down near the interface between the metal plate and the nip roll larger than the width of the metal plate, so that the metal Since the entire width of the plate is coated, the thickness of the coating resin in the width direction of the laminated metal plate becomes uniform.

[0020] Furthermore, since an oil film is formed in advance on the surface area of the non-cooled or heated roll that is covered by both ends in the width direction of the thermoplastic resin film, the thermoplastic resin that covers the surface area of the roll is The adhesion force of the film portion to the roll surface is reduced, and when the metal plate coated with the resin film in the center portion in the width direction is removed from the non-cooled or heated roll, it simultaneously coats the surface of the non-cooled or heated roll. The resin film at both ends in the width direction is detached from the uncooled or heated roll, thereby preventing the resin film from being wrapped around the uncooled or heated roll.

The thickness of the oil film formed in advance on the surface area of the uncooled or heated roll covered by both ends of the thermoplastic resin film in the width direction varies depending on the roll surface material, resin, type of oil, etc. When the roll is an uncooled rubber lined roll, the resin is polypropylene or polyethylene terephthalate, and the oil is cottonseed oil, the appropriate amount is 1 mg/m2 or more. That is, if the oil film thickness is too thin, the effect of reducing the adhesion of polypropylene or polyethylene terephthalate to the roll will be small, and winding around the roll cannot be prevented. Alternatively, for example, an oil film may be formed in advance over the entire surface of the roll, and a transfer oil film may be formed on the non-resin-coated surface of the metal plate, and at the same time, both widthwise ends of the thermoplastic resin film may be coated on the uncooled or heated roll. When reducing the adhesion force to prevent wrapping around the roll, the oil film thickness is 3000mg/
m2 or less is appropriate. That is, if it is too thick, the performance of the laminated metal plate, such as paint adhesion, will deteriorate, so it is not suitable.

The method of the present invention will be explained in detail below with reference to the drawings. FIG. 1 shows an example of an apparatus for carrying out the method of the present invention, in which a metal plate 3 discharged from an unwinding reel 11 is
For example, the metal plate 3 is preheated with a gas-heated preheating device 12, passed through a turndown roll 13, and then wrapped around a non-cooled or heated roll 1. The nip roll 2 is pressed against the metal plate 3 wound around the roll 1, and then Above nip roll 2
A molten thermoplastic resin film 6 flows down from the slit-shaped opening of the T-die 5 through the extruder 4 and is laminated on the metal plate 3 at the interface of the metal plate 8 laminated with the thermoplastic resin film.
Continuous laminated metal plate production in which the laminate metal plate 8 is cooled down to room temperature, for example, by a cooling device 7 equipped with a gas jet nozzle, and the laminated metal plate 8 at room temperature is obtained and wound onto a take-up reel 14. In the apparatus, for example, felt impregnated with oil is pressed onto the non-wrapped portion of the metal plate 3 of the uncooled or heated roll 1 to form an oil film width over the entire surface of the roll 1 having a body length WR as shown in FIG. W
. An oil film forming device 15 that continuously forms an oil film of (=WR) is disposed, and the T-die 5 has slit-shaped opening width adjusting plates 16, 16 as shown in FIG. 2 to form a thermoplastic resin film. A T-die whose width can be adjusted is used, and as shown in FIGS. 1 and 2, the width WP of the thermoplastic resin film 6 flowing down near the interface between the metal plate 3 and the nip roll 2 is equal to the width W of the metal plate 3.
M is made larger than M, so that the central part WPM in the width direction where the thickness distribution of the resin film 6 is uniform covers the metal plate 3 and the thickness distribution of the resin film 6 is uneven as shown in FIGS. 2 and 3. The laminated metal plate 8 is continuously manufactured by adjusting the line width direction position of the T-die 5 and the width WT of the slit-shaped opening of the T-die 5 so that the widthwise both ends WPE cover the uncooled or heated roll 1. It is something to do.

In this way, the width WP of the thermoplastic resin film 6 flowing down near the interface between the metal plate 3 and the nip roll 2 is made larger than the width WM of the metal plate 3, and the thickness of the thermoplastic resin film 6 is increased. Since the entire width of the metal plate 3 is coated with the uniformly distributed central part WPM in the width direction, the thickness of the coating resin in the width direction of the laminated metal plate 8 is uniform, and the product yield of the laminated metal plate 8 is increased. Can be done.

[0024] Furthermore, an oil film is formed in advance on the surface area (WP-WM) of the non-cooled or heated roll 1 covered by the widthwise both ends WPE of the thermoplastic resin film 6 having an uneven film thickness distribution. Therefore, the surface area (W
The adhesion force of the thermoplastic resin film 6 coated with P-WM) to the roll surface at both ends WPE in the width direction is reduced, and the metal plate 3 covered with the resin film 6 at the center part WPM in the width direction is not cooled. Alternatively, at the time of detachment from the heating roll 1, the resin film of the WPE at both ends in the width direction that coats the surface of the uncooled or heated roll 1 simultaneously separates from the uncooled or heated roll 1 and winds around the uncooled or heated roll 1. is prevented,
The laminated steel plate 8, which can be operated satisfactorily and has a resin film on both outer sides of both ends in the width direction, is wound onto the take-up reel 14.

[0025] In this example, the laminated steel plate 8 is wound up with the resin film on both outer sides of both ends in the width direction.
For example, by providing a resin cutter between the cooling device 7 and the take-up reel 14, the resin film on both outer sides of the laminated steel plate 8 at both ends in the width direction can be removed by cutting and then the laminated steel plate 8 can be wound up.

[0026]

[Example] The outer diameter of the non-cooled roll 1 in Fig. 1 is 450 mm.
, an internal non-cooled rubber lining roll with a body length of 1200 mm was used, and an outer diameter of 300 mm and a body length of 1 was used as the nip roll 2.
Using a continuous laminated metal plate manufacturing device that employs a 200 mm internal uncooled silicone rubber lining roll, an electrolytic chromic acid treated steel plate with a thickness of 0.2 mm and a width of 800 mm was used as the metal plate 3, and this steel plate was heated to 200°C. After preheating, the oil film forming device 15 spreads 30 m over the entire length of the roll body.
Polyethylene terephthalate was melt-extruded and flowed down from a T-die 5 through an extruder 4 onto the interface between the nip roll and the surface of the steel sheet wrapped around the uncooled roll 1 on which an oil film of g/m2 was formed. The temperature of the molten resin is 280℃, and the coating width is 8
60 mm, and the steel plate was covered 30 mm wider on each side than the steel plate. The line speed at this time was 50 m/min, and the angle at which the steel plate was wound around the non-cooled roll after pressure welding was 90 m/min.
°.

The laminated steel plate reached the cooling device 7 downstream of the uncooled roll 1 in 3 seconds after pressure welding, was cooled to room temperature by a gas jet, and then wound up to obtain 8 coils of laminated steel plates. The resin coated in a wider width than the steel plate does not adhere to the uncooled roll 1 around which the steel plate is wound, and the laminated steel plate 8 can be wound up with the resin film on both outer sides of both ends in the width direction, improving operability. The thickness distribution of the resin film in the width direction of the obtained laminated steel plate 8 was constant at 50 μm, and the manufacturing yield of the laminated steel plate was 100%.

[0028]

[Comparative Example 1] As a comparative example, when the above example was operated without forming an oil film on the non-cooled roll 1, the resin coated wider than the steel plate adhered to the non-cooled roll 1 around which the steel plate was wound. It got wrapped around the cooling roll 1 and became inoperable.

[0029]

[Comparative Example 2] As a comparative example, an operation was performed in which no oil film was formed on the uncooled roll 1 in the above example, and the width of the slit-shaped opening of the T-die 5 was adjusted so that the molten resin coating width was 800 mm. The thickness distribution in the width direction of the resin film at the center 750 mm in the width direction of the obtained laminated steel plate 8 was constant at 50 μm. However, the thickness distribution in the width direction of the resin film at both widthwise ends of 25mm is uneven, and the product must be manufactured by trimming both widthwise ends of 25mm, and the manufacturing yield of the laminated steel sheet is 9.
It was 3%.

[0030]

As described in detail above, according to the present invention, a laminated metal plate having excellent corrosion resistance and adhesion can be manufactured with a high yield.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example of an apparatus for carrying out the method of the present invention.

FIG. 2 is an explanatory diagram of an example of an apparatus for carrying out the method of the present invention.

FIG. 3 is an explanatory diagram of an example of an apparatus for carrying out the method of the present invention.

FIG. 4 is an explanatory diagram of a conventional method.

FIG. 5 is an explanatory diagram of the first-to-file method.

[Explanation of symbols]

1　　　Non-cooled or heated roll 2 Nip roll 3 Metal plate 4 Extruder 5 T-die 6 Thermoplastic resin film 7 Cooling device 8 Laminated metal plate 9 Heating roll 10 Cooling roll 11 Unwinding reel 12 Preheating device 13 Turndown roll 14 Take-up reel 15 Oil film forming device 16 Slit-shaped opening width adjustment plate

Claims (1)

[Claims] Claim 1: A nip roll is pressed against a preheated metal plate that is wound around an uncooled or heated roll, and a T
In a method for producing a laminated metal plate in which a metal plate is coated with a thermoplastic resin film by flowing a molten thermoplastic resin film from a die, the width of the thermoplastic resin film flowing down near the interface between the metal plate and the nip roll is determined by the width of the thermoplastic resin film flowing down from the metal plate. The width of the thermoplastic resin film is larger than the width of the plate, so that the central part in the width direction of the thermoplastic resin film covers the entire width of the metal plate, and the surface area of the uncooled or heated roll is covered by both ends of the thermoplastic resin film in the width direction. A method for manufacturing a laminated metal plate, which comprises forming an oil film in advance on the laminate metal plate.