JPS5940103B2 - Method for manufacturing a laminate made of metal and thermoplastic synthetic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a laminate made of metal and a thermoplastic synthetic resin. It relates to a manufacturing method.

Laminated plates made of metal and thermoplastic synthetic resin (hereinafter referred to as "synthetic resin") are basically produced by a method in which a metal sheet and a synthetic resin sheet in a molten state are fed between heated pressure rollers and bonded together. Can be manufactured continuously. However, when using the above method, there is a drawback that the metal sheet on the surface of the laminate is sometimes slightly misaligned, and the adhesion in that area is not sufficient.

In other words, as the metal sheet is long, as it is moved between various rollers, factors such as slight distortion of the metal sheet, fluctuations in wall thickness, expansion and contraction due to heat, etc., are amplified and slightly distorted. cause a misalignment.

Such misalignment not only appears as wrinkles and meandering on the product, but also especially when this misalignment occurs immediately after the metal sheet and synthetic resin sheet are laminated or before cooling. The synthetic resin, which is cooling and solidifying, cannot follow the deviation and move smoothly.
Therefore, sufficient adhesion is not performed in the portion where the deviation occurs, resulting in partial or local adhesion failure.

Such misalignment is particularly likely to occur when the metal sheet is thin, for example, 0.5 mm or less. Therefore, as a method for manufacturing a laminate that suppresses wrinkles and meandering of metal sheets,
There is a method described in Japanese Patent Publication No. 53-4071.

In this method, a metal sheet whose entire surface has been substantially uniformly preheated and stretched to a constant tension by a take-up roller, and a synthetic resin sheet in a molten state are fed between heated pressure rollers and bonded together. Another method is to cool the obtained laminate at a specific rate while maintaining the same tension as described above and without applying any restraining force other than the tension. According to this method, most of the metal sheets are cooled. This eliminates the misalignment and considerably suppresses wrinkles and meandering, but it is hoped that a more effective method will emerge. The present inventors improved the above method and more completely eliminated the misalignment of the metal sheet.
As a result of intensive studies aimed at providing a laminate with high adhesive strength over the entire bonded surface, we found that if the surface of the metal sheet is provided with irregularities, this will effectively absorb the slight deviations due to shrinkage, etc. mentioned above. I got the knowledge that I can get it.

The present invention has been achieved based on the above findings, and its gist is to supply a metal sheet with a thickness of 0.5 mm or less stretched to a constant tension between rollers having a large number of minute irregularities on its surface. After applying unevenness to the surface of the metal sheet, the entire surface is preheated substantially uniformly, and the sheet is fed together with a thermoplastic synthetic resin sheet in a molten state between heated pressure rollers for lamination. A method for producing a laminate made of metal and a thermoplastic synthetic resin, characterized by cooling the plate while maintaining the same tension as described above and without applying any restraining force other than the tension.

Hereinafter, the method of the present invention will be explained in detail with reference to the accompanying drawings.

The accompanying drawing is a side view schematically showing an example of the method of the invention.

First, the metal sheet 1 and synthetic resin sheet 2 used in the method of the present invention will be explained.

As the metal sheet 1, a sheet of aluminum, iron, copper, tin, nickel, or an alloy thereof is used.

The thickness of the metal sheet 1 is 0.5711 m or less, and a thickness of 0.05 to 0.5 m71 L is usually used. The synthetic resin sheet 2 is not particularly limited as long as it is normally used for extrusion molding, such as polyethylene, polypropylene, polybutene, polyvinyl chloride, polystyrene, polyamide, polycarbonate, etc., but polyethylene, polypropylene, polybutene, etc. Polyolefin-based synthetic resins such as the following are preferred from the viewpoint of extrusion moldability.
The thickness of the synthetic resin sheet 2 is not particularly limited and is selected appropriately depending on the desired thickness of the laminate, but generally,
It is 1 to 10 mm. The metal sheet 1 is an uncoiler 3
It is pulled out in a stretched state with a constant tension by a take-up roller 4.

The tension applied to the metal seam port can be changed arbitrarily by adjusting the braking force of the uncoiler 13, and is usually between 0.2 and 3.
It is controlled to a constant value in the range of 0.5 kg/M2. The stretched metal sheet 1 is first passed through a surface treatment step 5, where necessary surface treatments such as degreasing, washing, drying, etc. are performed according to conventionally known methods.

Next, the metal sheet 1 is fed between rollers 6 and 7 which have a large number of minute irregularities on the surface thereof, and a large number of minute irregularities are imparted to the surface of the metal sheet 1. The shape of the uneven portions provided on the surfaces of the rollers 6 and 7 is not particularly controlled, and may be any shape, such as a shape capable of imparting regular streaks to the surface of the metal sheet 1 or a shape capable of imparting random unevenness. The larger the number, the more effectively the displacement of the metal sheet 1 can be absorbed.
It is selected appropriately depending on the degree of misalignment, taking into consideration the thickness of the metal sheet 1 and the like. In addition, if the depth of the uneven portion is too shallow, the effect of absorbing misalignment will not be sufficiently exerted, and if it is too deep, the effect of absorbing misalignment will not be large enough.
Not only that, but shearing may occur when providing unevenness to one surface of the metal sheet, and furthermore, the synthetic resin may not be able to fill the unevenness, which may even lead to poor adhesion.
It is selected from the range of 10 to 300μ, preferably 50 to 250μ. The metal sheet 1 with an uneven surface is
After being preheated through a preheating step 8, the synthetic resin sheet 2 in a molten state is extruded from an extruder 9 and is supplied between heated pressure rollers 10 and 1σ to perform bonding.

If the temperature of the synthetic resin sheet 2 is too low, the wettability between the resin and the metal will be poor and the irregularities on the surface of the metal sheet 1 may not be filled with the resin, so consider the wettability between the resin used and the metal. However, when using polyolefin synthetic resin, it is approximately 180 to 240
It is best to choose from a range of ℃.

In addition, the temperature of the heated pressure bonding roller 10,1σ cannot be determined unconditionally because it varies depending on the type of synthetic resin, the drawing speed of the metal sheet 1, etc., but when using polyolefin-based synthetic resin, The surface temperature of the roller is approximately 180 to 230°C. Note that the preheating temperature of the metal sheet 1 is normally set by the heating pressure bonding roller 10,
The temperature is brought to around 10'. Pressure roller 10,1
(The laminate sent out from 1y is heated and matured in a heating step 11 if necessary, and then cooled in a cooling step 12 to become a product.

The method of the present invention involves applying irregularities to a metal sheet 1 stretched at a constant tension, then laminating it with a synthetic resin sheet 2 in a molten state, and then cooling it without changing the applied tension. This prevents poor adhesion due to displacement of the metal sheet 1. Therefore, in the method of the present invention, it is necessary to avoid the use of pinch rollers and the like and to avoid applying any restraining force other than tension. Also,
When manufacturing a laminate according to the method of the present invention, an adhesive can also be used, and in this case, it is preferable to mix the adhesive into the synthetic resin in advance.

Note that although the accompanying drawings illustrate the case where the metal sheets on both sides of the laminate are provided with unevenness, it is possible to prevent a considerable amount of poor adhesion even if only the metal sheet on one side is provided with unevenness. In addition, although the attached drawing shows an example of using two rollers 6 and 7 that have minute irregularities on their surfaces, we have considered the depth of the irregularities, the material of the rollers, etc. It can also be used in combination. However, the reason why partial or local adhesion failures can be prevented by imparting irregularities to the surface of the metal sheet according to the method of the present invention is not necessarily clear, but it can be inferred as follows. can.

The large number of minute irregularities imparted to the surface of the metal sheet 1 acts as a buffer and absorbs any misalignment that may occur on the surface of the metal sheet, so that virtually no movement of the metal sheet 1 occurs. As long as the adhesive is uniformly and evenly bonded by the roller 10, 1σ, there will be no adhesion failure.

According to the method of the present invention explained above, it is possible to obtain a laminate with high adhesive strength over the entire bonded surface. It is also possible to impart a design effect to the laminate by providing slightly deeper unevenness within a range that does not damage the laminate.

In other words, in recent years, in order to increase the commercial value of laminates, so-called embossing has been carried out to add lines, etc. to the obtained laminates. It is said that a thickness of 100 to 150μ or more is required to exhibit the desired effect.

However, in the case of the method of the present invention, the unevenness is imparted to the metal sheet itself before it is laminated with the synthetic resin sheet, so the unevenness becomes sharp and has a sharp contrast of about 50 to 100 μm. A sufficient design effect can be achieved by the unevenness of the surface. Therefore, in the case of the method of the present invention, compared to the case where the obtained laminate is subjected to the above-mentioned embossing process, only inexpensive roller equipment with a small processing load is used, and moreover, it causes various problems. It is also possible to impart a design effect to the laminate without causing processing distortion at the bonded interface.

[Brief explanation of the drawing]

The accompanying drawing is a side view schematically showing an example of the method of the invention. 1: Metal sheet, 2: Thermoplastic synthetic resin sheet, 3: Uncoiler, 4: Take-up roller, 6, 7: Uneven roller, 10,1σ: Heat pressure bonding roller.

Claims (1)

[Scope of Claims] 1. A metal sheet with a thickness of 0.5 mm or less stretched under a constant tension is supplied between rollers having a large number of minute irregularities on the surface thereof to give irregularities to the surface of the metal sheet, and then The whole is preheated substantially uniformly and laminated together with a thermoplastic synthetic resin sheet in a molten state by being fed between heated pressure rollers, and the resulting laminate is then maintained under the same tension as above. A method for manufacturing a laminate made of metal and thermoplastic synthetic resin, characterized in that the laminate is cooled without applying any restraining force other than the tension. 2. The method according to claim 1, characterized in that the depth of the minute unevenness is 10 to 300μ.
A method for manufacturing a laminate made of metal and thermoplastic synthetic resin. 3. In the method according to claim 1 or 2, the thermoplastic synthetic resin sheet in a molten state has a
A method for producing a laminate made of metal and thermoplastic synthetic resin, characterized in that the sheet is a 240°C polyolefin synthetic resin sheet.