JPH08446B2 - Method for manufacturing coated metal plate - 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 for producing a coated metal plate having excellent image clarity, and more specifically, for use as an outer panel for home electric appliances, furniture, interior plate for buildings, etc. which are required to have high image clarity. The present invention relates to a method for producing a plastic film-coated metal sheet suitable for use in.

[0002]

2. Description of the Related Art Conventionally, an ink layer having a PVC resin film as a base and having a pattern on one side of the film,
A composite film in which a PET resin film is laminated on the upper surface of the ink layer via an adhesive, a metal plate on which an adhesive layer is formed in advance is heated (180 ° C.) and roll-laminated, and further heated to 200 ° C., glossy plated pressurized with specular roll method as obtained by cooling high sharpness laminated metal plate has been disclosed (Japanese open Sho 63-280627).

In this method, as a step of laminating a composite film on a metal plate, in the first step, rolls are laminated at a plate temperature of 180 ° C., and in the second step, pressure is applied by a mirror-finished roll heated to 200 ° C. This is a method of finishing the film surface to a smooth surface.

That is, in the lamination of the first step, the PVC resin layer maintains the state of from the softening point to the melting point, and in the lamination of the second step, the transparent hard layer side (PET resin film) with the mirror surface roll heated to 200 ° C. By applying more pressure, the PVC resin layer absorbs the discontinuous ink layer having a pattern pattern, which causes unevenness on the surface of the laminated metal plate.
The surface of the resin film becomes smooth, and a high-definition laminated metal plate is obtained.

However, the present invention is a laminating method effective for smoothness and image clarity of a laminated metal sheet surface film, but since the laminating means requires two steps in the manufacturing process, the number of laminating facilities is increased.・ It is not desirable from the aspect of equipment such as heat saving source and dust prevention measures.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been studied to solve such a problem, and the process of laminating a composite film on a metal plate is performed in one step with efficient and inexpensive equipment.
An object of the present invention is to provide a manufacturing method capable of obtaining a laminated metal plate which has high productivity and is smooth and has excellent image clarity.

[0007]

That is, according to the constitution of the present invention, a thermoplastic resin-based adhesive is applied onto a metal plate coated with a chemical conversion coating, and the metal plate temperature is adjusted by passing it through a heating furnace. Is heated to a temperature not lower than the melting point and not higher than 230 ° C. to form an adhesive layer, and vinyl chloride (PV
C) A composite film made by laminating a biaxially stretched synthetic resin film via an adhesive on a resin film is overlaid, and the surface temperature of a metal having specular gloss is changed from the heat deformation temperature of the synthetic resin film to the melting point. Using the upper and lower rolls consisting of the upper heat roll heated to the above range and the lower roll lined with heat-resistant rubber, pressure is applied with a pressing force of 5 to 10 kg / cm ² . A method for producing a plastic film-coated metal sheet having excellent image clarity, characterized by spraying cooling water to the back side of the obtained laminated metal sheet immediately after pressure bonding and cooling.

The present invention will be described in detail below.

Examples of the metal plate used in the present invention include hot dip galvanized steel plate, electrogalvanized steel plate, cold rolled steel plate, aluminum plate and stainless steel plate. Since the temperature of the metal plate is higher than the melting point of the PVC resin film, the film will be in a molten state at the same time as the film is laminated, and the PV
Since the C resin flows and is filled, the smoothness of the biaxially stretched synthetic resin film surface can be maintained without being affected by the roughness of the metal surface. A chemical conversion treatment film is applied to these metal plates by a known chemical conversion treatment liquid.

Next, an adhesive is applied, and the composite film is laminated on the adhesive and pressed through the space between the upper and lower laminating rolls, and then rapidly cooled to obtain the coated metal plate of the present invention.

As the adhesive between the metal plate and the composite film, those used for conventional vinyl chloride steel plates and the like can be used, and there are thermoplastic resin adhesives such as acrylic resin adhesives and polyester resin adhesives. .

As the composite film, a semi-rigid polyvinyl chloride (PVC) film and a biaxially stretched polyethylene terephthalate (PET) resin film, polybutylene terephthalate (PBT) resin film, polypropylene (PP) resin film and the like are used. Examples include those laminated via a urethane resin adhesive.

Lamination of the metal plate and the composite film is performed by passing between the upper and lower rolls. In this case, as the upper laminating roll, a mirror-shaped heat roll made of metal and plated with gloss is used.

In this case, the surface temperature of the upper heat roll is maintained at a constant temperature within the range from the heat deformation temperature of the biaxially oriented film for the surface layer to the melting point. When the temperature is less than the heat deformation temperature of the biaxially stretched film, the ironing effect of the heat roll is weakened, the surface gloss of the biaxially stretched film is lowered and the image clarity is poor.

When the surface temperature of the heat roll is equal to or higher than the melting point of the biaxially stretched film, for example, in the polyethylene terephthalate resin film (hereinafter referred to as PET film), the oligomer contained therein oozes out to impair the specular gloss of the heat roll, resulting in sharpness. Is inferior.

As the lower laminating roll, for example, a roll lined with silicone rubber is used.
When a metal roll is used, it is difficult to control the gap between upper and lower rolls and pressurization due to variations in the thickness of the metal plate, and it is difficult to obtain a uniform appearance. Therefore, a heat-resistant rubber lining roll used for laminating general PVC resin film is used on the lower side to absorb pressure fluctuations and obtain a stable appearance.

The upper and lower rolls are pressed with a pressing force of 5 to 10 kg / cm ² .

When a pressing force of 10 kg / cm ² or more is applied, the PVC resin of the lower surface layer of the composite film protrudes to the left and right end sides of the coated metal plate and impairs the external appearance, and the coated metal plate after cooling is warped. The resulting plate damages the shape of the plate. With a pressing force of 5 kg / cm ² or less, the rolling effect is insufficient, the surface of the film becomes uneven, and the smoothness is poor and the sharpness is reduced.

The coated metal sheets pressure-bonded by the upper and lower laminating rolls are rapidly cooled by spraying cooling water from the back side of the coated metal sheets at the same time when the coated metal sheets are released from the rolls. By quenching, the surface smoothness of the biaxially stretched film can be maintained. If the surface of the film is cooled rapidly with cooling water, the film surface will be uneven and the image clarity will be poor, and it will not be a product.

[0020]

In the present invention, a film obtained by coating an adhesive agent on a metal plate and passing it through a heating furnace to form a composite film in advance in an adhesive layer in an active state is a mirror-like heat roll whose upper laminating roll is made of metal and is plated with gloss. The lower laminating roll consists of conventional rubber lining rolls, and the upper and lower rolls are passed between the upper and lower rolls while maintaining a pressing force of 5 to 10 kg / cm ² , and the composite film is pressure-laminated on the metal plate. By doing so, the biaxially stretched synthetic resin film of the composite film upper layer is heated to be softened and smoothed, and further, when the upper and lower laminating rolls are released, a contraction phenomenon of the film is caused, and the composite film upper layer is further smoothed. become.

By rapidly jetting cooling water from the back side of the coated metal plate, it is possible to manufacture a plastic film-coated metal plate which is excellent in image clarity while maintaining a smooth state.

[0022]

EXAMPLES Examples will be described below. FIG. 1 shows a schematic view of the steps.

Galvanized steel sheet coated with zinc phosphate 1
Acrylic resin adhesive 2 is applied on top of it so as to have a dry film thickness of 5 μm, and it is passed through a heating furnace 3 to heat the metal plate temperature to 210 ° C. to form an adhesive layer in an active state. P
Biaxially stretched polyethylene terephthalate (P resin film (100 μm thick) through urethane resin adhesive (P
ET) resin film (25 μm thick) is laminated, and the composite film 4 shown in FIG. 2 is used. The upper laminating roll 5 has a mirror-like luster and the metal heat roll having a surface temperature of 180 ° C. and the lower laminating roll 6 have As the rubber-lined rolls, the upper and lower rolls were pressed at 7 kg / cm ² at a plate temperature of 210 ° C. and pressure-bonded onto the adhesive layer of the metal plate, and then the cooling water 8 was quickly sprayed on the back side of the laminated metal plate to cool it, It is possible to manufacture the plastic film-coated metal plate having excellent image clarity shown in FIG.

[0024]

The present invention utilizes the conventional laminator line, and only the upper laminating roll is replaced with a mirror-like heat roll made of metal and plated with gloss,
It is possible to manufacture a synthetic resin film-coated metal plate with high image clarity.

Further, even if the surface roughness of the metal plate to be used is not limited, it is possible to produce a coated metal plate which is smooth in one step and has excellent image clarity, so that there is a great effect in terms of equipment and quality. There is.

[Brief description of drawings]

FIG. 1 is a schematic process diagram of an example of the present invention.

FIG. 2 is a cross-sectional configuration diagram of a composite film.

FIG. 3 is a cross-sectional configuration diagram of a film-coated metal plate of the present invention.

[Explanation of symbols]

 1 Metal Plate 2, 9 Adhesive Layer 3 Heating Furnace 4 Composite Film 5 Upper Heat Roll 6 Lower Rubber Roll 8 Cooling Water 10 PVC Resin Film 11 Coated Metal Plate

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location B32B 31/12 7148-4F 31/20 7148-4F 31/24 7148-4F // B29K 27:06 B29L 7: 00 9:00

Claims (1)

[Claims] 1. A metal plate coated with a chemical conversion coating is heat-treated.
Apply a plastic resin adhesive and pass through a heating furnace to keep the metal plate temperature
Contact by heating above the melting point of PVC resin film to 230 ° C or less
Forming an adhesive layer, and preparing a PVC tree on the adhesive layer in advance
A synthetic resin film biaxially stretched on an oil film with an adhesive.
Laminated composite films made by laminating layers
The surface temperature of glossy metal is the heat of synthetic resin film.
Upper heat low heated from the deformation temperature to the melting point
And upper and lower rolls made of heat-resistant rubber lining
Passing between rolls, pressurizing force 5-10kg / cm² After crimping with, got
The cooling water is sprayed on the back side of the laminated metal plate
Plastic film coated metal with excellent image clarity
Method of manufacturing a plate.