JP3048781B2 - Manufacturing method of laminated metal sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a thermoplastic resin-coated metal sheet having excellent adhesion, workability, corrosion resistance and appearance with good yield.

[0002]

2. Description of the Related Art Conventionally, as a surface-treated metal sheet coated with a synthetic resin, a color steel sheet obtained by applying a thermosetting acrylic resin paint or a polyester resin paint or a laminated steel sheet obtained by laminating a resin film is known. .

Because of their beautiful colors, appearance and corrosion resistance, they are widely used in applications such as construction, interior materials for buses and passenger cars, materials for home electric appliances, and furniture furniture.

[0004] However, the resin used for the paint is
Due to the necessity of coating workability, those with relatively low molecular weight are used, and the high molecular weight is not sufficient even by baking and hardening after coating, and the flow on the metal substrate is not sufficient, and the defect that durability is lacking there were.

[0005] On the other hand, a laminated steel sheet on which a resin film is laminated uses a film extruded from a resin such as a vinyl chloride resin, an acrylic resin, or a fluororesin, which has a consistently high molecular weight at a petrochemical plant. The molecular weight is much higher than that of the resin for coating, and therefore, the durability of the coating film on the substrate is much longer, for example, about 10 to 20 years, compared with 3 to 5 years for coating. It is.

However, in this case, there are various problems as follows. (1) When the thickness of the film is reduced, uniform lamination on the substrate becomes difficult, and phenomena such as wrinkles appear on the surface. Therefore, the thickness is usually limited to about 50 μm.

(2) Since there are microscopic irregularities on the substrate, a space is easily generated between the solidified film and the substrate, and the adhesion of the film is insufficient.

(3) Since the resin is once formed into a film, the resin used is restricted in terms of film forming ability.

[0009] On the other hand, a metal substrate is heated with a heating roll.
Is preheated to a temperature in the range of ~ 170 ° C, and then proceeds through the gap between the heating roll and the cooling roll. It has been reported that by being press-bonded, a beautiful appearance can be obtained, and a surface-treated metal sheet having more excellent adhesion and corrosion resistance than conventional color steel sheets or laminated steel sheets can be obtained (Japanese Unexamined Patent Publication (Kokai) No. 2002-282686). No. 57-203545).

This metal plate has much better adhesion and corrosion resistance to a substrate than a conventional metal plate. further,
Since the coating is performed in a molten state directly from the T-die without forming into a film, the film thickness is also 50 μm or less, which is difficult with conventional film coating, and 35 μm or less.
Coating up to about μ thickness was made possible.

Since the durability of the surface-treated metal sheet is greatly affected by the type and thickness of the thermoplastic resin, it is desirable to be able to control the thickness in accordance with the required degree of durability and price requirements. However, coating with a thin film has been made possible by the present invention.

Further, for example, a hard resin or the like can be formed into a film, but is easily broken, and it is difficult to form the film once and then press it on a metal plate. Since the resin is coated in a state having properties, such a hard resin can be used.

In addition, since the film forming step is omitted, there is an advantage that the cost is reduced.

[0014]

However, the molten thermoplastic resin film flowing down from the slit-shaped opening of the T-die narrows (neck-in) as it flows down from the opening, and the thermoplastic resin film below the opening is opened. The resin flow rate per unit width in the width direction of the film is uniform at the center but is larger at both ends than at the center.

When the thickness of the thermoplastic resin film is equal to or smaller than the width of the metal plate, the thickness of the coating resin in the width direction of the obtained laminated metal plate becomes non-uniform, and the width in the width direction, which is the portion where the coating thickness is non-uniform, is not uniform. Both end portions do not become products, and the portions need to be trimmed in a later process, and the product yield is greatly reduced.

For this purpose, it is necessary to cover (overcoat) a metal plate with a width larger than the width of the metal plate. However, the overcoat resin adheres to the wound roll and the operation becomes impossible.

Therefore, there is a method of using a soft thin material as disclosed in JP-A-3-158235, but the cost of the soft thin material is high.

The present invention solves such a problem due to neck-in, and is excellent in adhesion, workability, corrosion resistance, and appearance.
The present invention also provides a method for manufacturing a thermoplastic resin metal plate having a good yield.

[0019]

That is, the present invention provides: (1) a preheated metal plate wound on a winding roll;
In a method of manufacturing a laminated metal plate by pressing a pressure roll and pressing a thermoplastic resin film melted from a T-die through an extruder into a gap between the pressure roll and the metal plate to cover the metal plate with the thermoplastic resin. The width of the thermoplastic resin film flowing down into the gap between the pressure roll and the metal plate is made larger than the width of the metal plate, and the entire width of the metal plate is covered at the center in the width direction of the thermoplastic resin film. A method for manufacturing a laminated metal plate, comprising cooling by spraying a cooling medium onto the surface of the thermoplastic resin film in the overcoated portion,

(2) A pressing roll is pressed against a preheated metal plate wound around a winding roll, and a thermoplastic resin film melted from a T-die through an extruder in a gap between the pressing roll and the metal plate. In the method of manufacturing a laminated metal plate by coating the thermoplastic resin on the metal plate by flowing down, the width of the thermoplastic resin film flowing down into the gap between the pressure roll and the metal plate, larger than the width of the metal plate, Laminate metal that covers the entire width of the metal plate with the widthwise central portion of the thermoplastic resin film and that is cooled by pressing a cooling roll against the surface of the thermoplastic resin film in a portion where the resin is overcoated. Plate manufacturing method,

(3) A pressing roll is pressed against the preheated metal plate wound around the winding roll, and a thermoplastic resin film melted from a T-die through an extruder in a gap between the pressing roll and the metal plate. In the method of manufacturing a laminated metal plate by coating the thermoplastic resin on the metal plate by flowing down, the width of the thermoplastic resin film flowing down into the gap between the pressure roll and the metal plate, larger than the width of the metal plate, While covering the entire width of the metal plate with the widthwise central portion of the thermoplastic resin film, the cooling roll is pressed against the widthwise ends of the winding roll where the resin is overcoated and / or a cooling medium is injected. A method for manufacturing a laminated metal plate, characterized in that it has been cooled in advance,

(4) A pressing roll is pressed against the preheated metal plate wound around the winding roll, and a thermoplastic resin film melted from a T-die through an extruder through a gap between the pressing roll and the metal plate. In the method of manufacturing a laminated metal sheet by coating a metal sheet with a thermoplastic resin by flowing down, the width of the thermoplastic resin film flowing down into the gap between the pressure roll and the metal plate is set to be larger than the width of the metal plate. While covering the entire width of the metal plate with the widthwise central portion of the plastic resin film, both ends in the width direction of the winding roll of the portion where the resin is overcoated are pressed against a cooling roll and / or a cooling medium is injected. Manufacturing a laminated metal plate, which is cooled in advance by pressing a cooling roll or spraying a cooling medium on the surface of the thermoplastic resin film in a portion where the resin is overcoated. Method

(5) The method according to (1), (2), (3) or (4), wherein an opening is provided near the surface of the winding roll where the overcoat resin contacts. is there.

Hereinafter, the present invention will be described in detail with reference to the drawings.

In the present invention, first, a roof,
Used for building materials such as walls and partitions, automotive materials, home electric products, furniture, cans, etc. A plated steel plate, an aluminum-plated steel plate, an aluminum alloy-plated steel plate, a stainless steel plate, or the like is used.

Further, those having a chemical conversion treatment layer of about 0.1 to 5 μm thereon are also included.

The chemical conversion treatment is performed as a surface treatment on a metal plate in order to improve the corrosion resistance, oxidation resistance and adhesion of the metal substrate. For example, a zinc phosphate treatment, an iron phosphate treatment, or an electrolytic chromate treatment Done by

Further, there is also included those having no chemical conversion treatment or after having been subjected to chemical conversion treatment and having an adhesive layer thereon.

The adhesive layer is a layer on which an adhesive of at least several μm is applied in order to improve the adhesion between the metal substrate and the thermoplastic resin.

As the adhesive, an adhesive thermoplastic resin having a functional group such as a modified polyethylene resin, a modified epoxy resin, and a modified vinyl resin is preferable.

These have good adhesion to both the metal and the thermoplastic resin used for coating. For example, in the case of a polyolefin-coated steel sheet, such as ethylene-vinyl acetate copolymer resin or ethylene-acrylic acid copolymer resin is used. Modified polyolefins are preferred.

The thermoplastic resin used for coating in the present invention is, for example, polyethylene terephthalate resin, polyolefin resin, acrylic resin, polyester resin, polyamide resin, vinyl chloride resin, fluorine resin, polycarbonate resin, polystyrene resin, ABS resin, chlorine resin. Polyether resins, urethane resins and the like are typical. Polyolefin resins include polymers or copolymers such as ethylene, propylene, 1-butene and 1-pentene, and acrylic resins such as acrylic acid and There are polymers or copolymers such as acrylic acid, acrylic acid ester, methacrylic acid ester, and acrylamide. Polyester resins include polyethylene terephthalate and oil-free polyester. Polyamide resins include so-called nylon 66 and nylon. Down 6, nylon 610, nylon 1
In addition to homopolymers, vinyl chloride resins include, for example, copolymers with ethylene and vinyl acetate, and fluorine resins include ethylene tetrafluoride resin, ethylene trifluoride chloride resin, and hexafluoroethylene resin. Ethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin and the like.

Further, two or more resins may be used as a mixture. Further, it may contain an additive usually used at the time of film formation, for example, a deterioration inhibitor, a modifier, a pigment and the like.

When coating in a molten state, a crosslinking agent such as an amino resin or an epoxy resin may be added to the extent that fluidity is not lost.

These thermoplastic resins are required to have weather resistance, suitability for cold regions, heat resistance, scratch resistance, stain resistance, chemical resistance, deep drawability, etc., depending on the use of the surface-treated metal sheet. Is appropriately selected according to the conditions. For example, polyolefins have excellent cold resistance, polyamides have excellent wear resistance,
Acrylic resin is excellent in stain resistance and chemical resistance, and fluorine resin is excellent in weather resistance.

[0036] Polyethylene terephthalate resin is particularly useful for acid resistant applications.

The resin may be a single layer coating or a multilayer coating of the same or different resins. In the case of multi-layer coating, for example, a multi-layer T die is used, and an adhesive layer can be provided between layers.

For example, on a steel sheet coated with an adhesive and preheated, a thermoplastic resin in a molten state is used as a lower layer, an adhesive resin is used as an intermediate layer, and a thermoplastic resin is used as an upper layer. It is possible to obtain a surface-treated steel sheet which is extruded into a film form and directly and continuously multi-layer coated, or an adhesive resin in a molten state on a preheated steel sheet as a first lower layer,
Surface treatment of extruding thermoplastic resin into the second intermediate layer, adhesive resin into the third intermediate layer, and thermoplastic resin into the fourth uppermost layer in the form of a film with a four-layer T-die, and directly and continuously multilayer coating. Steel sheet can be obtained.

Next, the manufacturing process will be described with reference to the drawings.

The metal substrate needs to be preheated before coating with the molten resin.

For example, in the case of polyethylene terephthalate, the melting point (255 ° C.)-120 ° C. or more (therefore, 135 ° C.)
(About 255 ° C.) is preferable.

The preheating increases the fluidity of the resin and improves the adhesion.

When preheating is not performed, or when the preheating temperature is low, especially when a cooling roll is used, the adhesion of the resin is not sufficient, resulting in lack of corrosion resistance.

The higher the preheating temperature, the higher the flowability of the resin, which is preferable. However, if the preheating temperature is too high, the resin and the adhesive are decomposed, which is not preferable. It is not preferable from the viewpoint of energy saving.

Therefore, the preheating is performed at a temperature lower than the temperature of the molten resin, preferably at a temperature lower by at least 50 ° C. than the temperature of the molten resin, usually about 50 to 230 ° C.

FIG. 1 shows that a pressing roll 5 is pressed against the surface of a preheated metal substrate 1 wound around a winding roll 4, and the interface between the metal substrate surface and the pressing roll 5 is passed through an extruder to form a T. 1 shows a method of manufacturing a laminated metal plate in which a molten thermoplastic resin film 3 flows down from a die 2 and a thermoplastic resin film is coated on a metal substrate 1.

According to this method, the film thickness and the surface condition can be easily adjusted. For example, it is easy to adjust the gloss of the surface and to give the surface an embossed pattern.

Metal substrate 1 coated with high-temperature molten resin 3
Is subjected to cooling and winding. Cooling, for example, after air cooling
You can spray with water or go through a water cooling tank,
It may be passed through a cooling roll.

Thus, the surface-treated metal sheet of the present invention is obtained. In the present invention, a cooling medium is sprayed on the overcoated resin or a cooling roll is pressed against the resin.
Or, the width direction both ends of the winding roll of the portion where the resin is overcoated, by pressing the cooling roll and / or injecting a cooling medium and pre-cooling, or by using these two or more methods together It promotes cooling and solidification of the resin, reduces the adhesion between the surface of the winding roll and the overcoat resin, and facilitates peeling from the winding roll.

When the temperature of the resin is high, the resin sticks and easily sticks to the winding roll, and the resin itself is soft.
It is torn and clings to the wrapping roll.

Further, by lowering the temperature of the surface of the winding roll, the adhesive strength with the resin is reduced, and although indirect, the cooling and solidification of the resin are promoted, and the resin is easily peeled off from the winding roll.

Next, this will be described with reference to the drawings.

FIG. 2 is an explanatory view for explaining a case where a cooling medium is jetted through the cooling nozzle 10 onto the surface of the thermoplastic resin film 3 to cool the surface. A cooling roll may be used instead of or simultaneously with the cooling nozzle.

As the cooling medium, air, water, steam-water (mist) in which water and air are mixed, liquid nitrogen, and the like are preferable from the viewpoint of economy and cooling capacity.

In order not to cool the metal plate itself, FIG.
As shown in (1), a partition 9 may be provided at the end of the metal plate so that the cooling medium does not fall on the metal plate.

FIG. 4 shows a cooling nozzle 10, and FIG. 5 shows a cooling roll 11.
An example of cooling is shown.

The winding roll is preferably made of Teflon or silicon in order to weaken the adhesion of the resin.

The cooling roll is preferably made of copper or iron from the viewpoint of the cooling effect.

Hereinafter, an embodiment will be described.

[0060]

EXAMPLE A winding roll having an outer diameter of 450 mm and an outer diameter of 200 m
The thickness of the metal plate is 0.2 mm using a laminated metal plate manufacturing apparatus using a nip roll (compression roll) of m
, A surface-treated steel sheet having a width of 800 mm is used.
After preheating to 0 ° C., a polyethylene terephthalate resin was melt-extruded and flowed down from a T-die through an extruder at the interface between the steel sheet surface and the nip roll.

The temperature of the molten resin is 280 ° C., the coating thickness is 50 μm, the coating width is 860 mm, the coating is 30 mm wider on both sides than the steel plate, and the line speed is 20 m / m.
and the angle at which the steel sheet is wound around the winding roll after pressing is 90 °.

(1) Using an air nozzle, air was blown on the surface of the overcoated resin after the pressure welding until the winding of the steel sheet was completed.

The overcoat resin could be stably operated without sticking to the winding roll. At this time, a partition was provided at the end of the steel sheet so that the cooling medium did not cover the steel sheet side.

(2) Air is blown to the surface of the winding roll using an air nozzle, and the width is 30 mm and the outer diameter is 50 m.
The cooling roll of the system in which water flows into the inside of the copper roll of m was brought into contact with the surface to cool the surface of the winding roll.

The overcoat resin could be stably operated without sticking to the winding roll.

(3) The above (1) and (2) were combined and carried out. In this case, the operation was possible without any problem, and the operation was satisfactorily performed even when the line speed was further increased (about 40 m / min).

Further, the operation is carried out in the same manner as described above (condition (3)) using a winding roll provided with an opening in the vicinity of the surface of the roll in contact with the resin protruding from the steel sheet as shown in FIG. Then, I increased the line speed even faster,
Even at about 50 m / min, the operation was good.

As a comparative example, when the operation was performed without cooling in the above example, the resin protruding from the metal plate was immediately wound around the winding roll around which the metal plate was wound, and the operation became impossible.

[0069]

According to the present invention, a laminated metal plate excellent in adhesion, workability, corrosion resistance and appearance can be manufactured with good yield.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a method of coating by flowing a molten resin onto an interface between a metal substrate and a roll.

FIG. 2 is an explanatory diagram of an example in which a resin surface is cooled by a cooling nozzle.

FIG. 3 is an explanatory view of the method of the present invention showing a partition position.

FIG. 4 is an explanatory diagram of an example in which a winding roll is cooled by a cooling nozzle.

FIG. 5 is an explanatory diagram of an example in which a winding roll is cooled by a cooling roll.

FIG. 6 is an explanatory diagram of a perforated roll used in the example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate 2 T die 3 Thermoplastic resin 4 Winding roll 5 Pressure roll 6 Cooling device 7 Water spray cooling device 8 Overcoat resin 9 Screen 10 Cooling nozzle 11 Cooling roll 12 Opening

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hirofumi Minamisato 1 Fujimachi, Hirohata-ku, Himeji City Nippon Steel Corporation Hirohata Works (56) References JP-A-61-127331 (JP, A) JP-A-6-285991 (JP, A) JP-A-55-107428 (JP, A) JP-A-1-301317 (JP, A) JP-A-6-71774 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) B29C 65/00-65/78 B32B 31/00-31/30 B32B 15/08

Claims (5)

(57) [Claims] 1. A pressing roll is pressed against a preheated metal plate wound around a winding roll, and a thermoplastic resin film melted from a T-die through an extruder is placed in a gap between the pressing roll and the metal plate. In the method of manufacturing a laminated metal sheet by coating a metal sheet with a thermoplastic resin by flowing down, the width of the thermoplastic resin film flowing down into the gap between the pressure roll and the metal plate is set to be larger than the width of the metal plate. A laminated metal plate that covers the entire width of the metal plate with the widthwise central portion of the thermoplastic resin film and that is cooled by spraying a cooling medium onto the surface of the thermoplastic resin film in a portion where the resin is overcoated. Manufacturing method. 2. A pressing roll is pressed against a preheated metal plate wound around a winding roll, and a thermoplastic resin film melted from a T-die via an extruder is placed in a gap between the pressing roll and the metal plate. In the method of manufacturing a laminated metal sheet by coating a metal sheet with a thermoplastic resin by flowing down, the width of the thermoplastic resin film flowing down into the gap between the pressure roll and the metal plate is set to be larger than the width of the metal plate. A laminated metal plate that covers the entire width of the metal plate with the widthwise central portion of the thermoplastic resin film and cools by pressing a cooling roll against the surface of the thermoplastic resin film in a portion where the resin is overcoated. Manufacturing method. 3. A pressing roll is pressed against a preheated metal plate wound around a winding roll, and a thermoplastic resin film melted from a T-die through an extruder is placed in a gap between the pressing roll and the metal plate. In the method of manufacturing a laminated metal sheet by coating a metal sheet with a thermoplastic resin by flowing down, the width of the thermoplastic resin film flowing down into the gap between the pressure roll and the metal plate is set to be larger than the width of the metal plate. While covering the entire width of the metal plate with the widthwise central portion of the plastic resin film, both ends in the width direction of the winding roll of the portion where the resin is overcoated are pressed against a cooling roll and / or a cooling medium is injected. A method for producing a laminated metal sheet, wherein the laminated metal sheet is cooled in advance. 4. A pressing roll is pressed against a preheated metal plate wound around a winding roll, and a thermoplastic resin film melted from a T-die through an extruder through a gap between the pressing roll and the metal plate flows down. In the method of manufacturing a laminated metal plate by coating the metal plate with a thermoplastic resin, the width of the thermoplastic resin film flowing down into the gap between the pressure roll and the metal plate is made larger than the width of the metal plate, the thermoplastic resin While covering the entire width of the metal plate with the widthwise central portion of the resin film, the widthwise both ends of the winding roll of the portion where the resin is overcoated, by pressing the cooling roll and / or spraying the cooling medium. A method for producing a laminated metal sheet, comprising cooling in advance and cooling by pressing a cooling roll or spraying a cooling medium on a surface of a thermoplastic resin film in a portion where a resin is overcoated. . 5. The method according to claim 1, wherein an opening is provided in the vicinity of the surface of the winding roll contacting the overcoat resin.