JP2000271685A - Manufacture of resin-coated container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a resin-coated container excellent in adhesivity which is excellent in resin adhesibiling after the drawing and ironing, capable of preventing the containers from being fixed to each other through the heat treatment. SOLUTION: The manufacturing method comprises a process to draw and iron a resin coat in which a base material consisting of a metal or an alloy is adhered to a resin film formed on at least one surface of the base material by an adhesive whose softening point is >=40 deg.C but not higher than the softening point of the resin film, and a process to achieve the heat treatment at the temperature of not lower than the softening point of the adhesive but not higher than the melting point of the resin film.

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 resin-coated container having excellent resin adhesion suitable for a molded article processed into a cap or the like, and more particularly to an outer container for electronic parts, such as an electrolytic capacitor. The present invention relates to a method for manufacturing a resin-coated container that can be used for a capacitor cap or the like that stores elements.

[0002]

2. Description of the Related Art Many aluminum electrolytic capacitors are:
A capacitor element impregnated with electrolyte is housed in a bottomed cylindrical capacitor cap formed by drawing an aluminum or aluminum alloy plate by drawing.The opening of the capacitor cap is sealed with rubber or the like, and the outer peripheral surface is electrically It has a configuration in which it is covered with a heat-shrinkable tube made of vinyl chloride resin or polyolefin resin for the purpose of insulation or content display.

In recent years, it has been difficult to cover a heat-shrinkable tube with a small aluminum electrolytic capacitor, and since the outer container has become smaller, the stored capacitor element has come into contact with the inner surface of the container, thus impairing insulation. There is.

Further, as a measure against dioxin associated with environmental protection in recent years, vinyl chloride has been decomposed, and even in a large aluminum electrolytic capacitor, it is desired to omit a vinyl chloride resin film covering the capacitor.

As a countermeasure, a laminated material in which the surface of an aluminum or aluminum alloy plate is previously coated with an insulating resin layer is drawn and ironed (hereinafter referred to as DI processing) to form an outer container, in which a capacitor element is formed. A technique has been put into practical use in which a tube is covered and the insulation is improved by squeezing the mouth. As a method of coating the insulating resin layer, there is a method of coating the surface of the aluminum or aluminum alloy material by bonding a resin film to the surface as described above.

[0006] As a laminated material obtained by laminating a resin film on the above-mentioned aluminum or aluminum alloy material,
Japanese Patent Application Laid-Open No. 1-238931 discloses a heat-treated epoxy resin coating between a polyamide resin and a metal material surface. Japanese Patent No. 2623598 discloses a metal plate in which a nylon resin is laminated on at least one surface of a metal plate.

[0007]

However, the above-mentioned conventional laminated material (Japanese Patent Laid-Open No. 1-238931, Japanese Patent No.
No. 3598), when DI processing is performed, even if the resin is hardened and the adhesiveness of the resin before processing is good, the adhesiveness of the resin is reduced and delamination or the like easily occurs after the processing. There is a point.

Therefore, heat treatment is performed at a relatively high temperature after DI processing. In Japanese Patent No. 2623598,
It is disclosed that in order to improve the adhesion after processing the container, heat treatment is performed in a heating temperature range in which the loss on heating from the melting point of the resin film is 10% by weight or less. However, there is a problem that when the heat treatment is performed collectively, the individual containers are fixed.

As a countermeasure, as proposed in Japanese Patent No. 2595668, it is necessary to use a heat treatment method and a heat treatment apparatus for individually treating containers.
There is a problem that it is extremely disadvantageous in terms of productivity as compared with the current capacitor cap.

The present invention has been made in view of the above problems, and has excellent resin adhesion after drawing and ironing, and excellent resin adhesion that can prevent sticking of containers by heat treatment. An object of the present invention is to provide a method for manufacturing a coated container.

[0011]

According to a method of manufacturing a resin-coated container according to the present invention, a base material made of a metal or an alloy and a resin film formed on at least one surface of the base material are softened at a temperature of 40 ° C. A step of squeezing and ironing the resin coating material bonded by an adhesive having a softening temperature of the resin film or lower,
Heat treating at a temperature not lower than the softening temperature of the adhesive and not higher than the melting point of the resin film.

In this case, it is preferable that the heat treatment is performed at a temperature of 50 ° C. lower than the melting point of the resin film and lower than the melting point of the resin film.

In the present invention, after a resin coating material having a resin film formed on at least one surface of a metal or alloy substrate via an adhesive is drawn and ironed, the resin film is heated at a temperature not lower than the softening temperature of the adhesive. By performing the heat treatment at a temperature equal to or lower than the melting point, a container having excellent adhesion of the resin film and free from adhesion of the resin film can be formed. For this reason,
A plurality of containers can be heat-treated at the same time, and productivity can be improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a resin-coated container according to an embodiment of the present invention will be described in detail. As a result of intensive experimental research, the present inventors have found that a resin-coated metal material having a resin film formed on at least one surface of a substrate made of a metal or an alloy via an adhesive layer having a softening temperature of the resin film at room temperature or higher is converted to DI. After processing to form a container, it was found that heat treatment was performed in a heating temperature range from the softening temperature of the adhesive to the melting point of the resin film or lower.

Hereinafter, the container of the present invention having excellent resin adhesion and the reason for limiting the production method thereof will be described in detail.

The type of the base material made of a metal or an alloy is not particularly limited. For example, an aluminum base material, a copper base material, an iron base material, and an alloy base material made of these alloys are used. be able to. The thickness of the base material is preferably 0.2 to 0.6 mm. Furthermore, in order to improve the adhesion to the resin film, the surface is formed with one kind of film selected from the group consisting of a chemical conversion treatment with phosphoric acid-chromate and an etching treatment such as electrolytic etching. Can be used.

[0017] As the resin film resin film is not particularly limited, for example, if Porisuteru resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polyethylene isophthalate resin, polybutylene terephthalate resin, etc. and their It can be a resin film made of a copolymer. In addition, as long as it is a polyamide resin, nylon 6, nylon 66, nylon elastomer, and nylon polymer can be used.

Adhesive The adhesive is not particularly limited. For example, a polyisocyanate-based adhesive, a polyester-based adhesive, an acrylic-based adhesive, or the like can be used.

Heat treatment: The temperature of the resin film becomes higher than the softening temperature of the adhesive.
If the temperature of the heat treatment below the melting point is lower than the softening temperature of the adhesive, it takes time to recover the adhesiveness of the resin film, and the productivity is reduced. On the other hand, if the temperature of the heat treatment exceeds the melting point of the resin film, fixation occurs during the heat treatment, and the containers adhere to each other.
Therefore, the heat treatment is performed at a temperature equal to or higher than the softening temperature of the adhesive and equal to or lower than the melting point of the resin film. When the temperature lower by 50 ° C. than the melting point of the resin film is higher than the softening temperature of the adhesive, the heat treatment is preferably performed at a temperature of 50 ° C. or lower from the melting point of the resin film to a temperature lower than the melting point of the resin film. .

[0020]

EXAMPLES A resin-coated container is manufactured by the method of the present invention, and the results of tests on the adhesion of the resin coating and the state of fixation of the resin coating are described in detail with reference to comparative examples.

An aluminum plate having a thickness of 0.3 mm was used as a substrate, a polyethylene terephthalate resin film having a thickness of 25 μm was used as a resin film, and a commercially available isocyanate-based adhesive was used as an adhesive. . The melting point of the polyethylene terephthalate resin film as the resin film is 255 ° C., and the softening temperature of the adhesive is 115 ° C.

At room temperature (20 ° C.), the resin coating material was prepared by applying an adhesive to an aluminum plate so that the thickness after drying was 10 μm, and then pressing a polyethylene terephthalate resin film with a laminating roll.

Using this resin-coated material, a resin-coated container having a resin surface on the outside and having a diameter of 10 mm and a height of 20 mm was formed by drawing and ironing. 100 resin-coated containers were put together in a stainless steel container and heat-treated under various conditions shown in Table 1. The adhesiveness of the coated resin film on the side of the resin-coated container after the heat treatment was evaluated by peeling the tape from the edge. The evaluation of resin adhesion was evaluated as ◎ for very good, 、 for good, △ for slightly bad, and x for bad. Table 1 shows the results. In addition, "-" shown in Table 1 shows that evaluation cannot be performed.

[0024]

[Table 1]

As shown in Table 1, Examples Nos. 1 to 3 were excellent in adhesion and did not adhere. In addition, since Example No. 3 satisfied the claim 2 of the present invention, the adhesiveness was extremely excellent.

On the other hand, in Comparative Examples Nos. 4 and 5, good results could not be obtained in terms of adhesion and fixation.
In Comparative Example No. 4, since the heat treatment temperature was equal to or lower than the softening temperature of the adhesive, the adhesive did not adhere, but the adhesion was poor. Comparative Example No. 5 was in a fixed state because the heat treatment temperature exceeded the melting point of the resin film. For this reason, it was not possible to evaluate the adhesion of the resin film.

[0027]

As described in detail above, in the present invention,
By setting the heat treatment temperature to the softening temperature of the adhesive or the melting point of the resin film, it is possible to obtain a container in which the containers are not adhered to each other and the adhesion of the resin film is excellent. In addition, a plurality of containers can be processed at the same time without having to heat-treat the containers one by one, so that the productivity of the containers can be improved.

Further, the container molded product can be applied particularly to an electronic component such as a capacitor cap.

Claims (2)

[Claims] A softening temperature of a substrate made of a metal or an alloy and a resin film formed on at least one surface of the substrate are 4
A step of squeezing and ironing a resin coating material bonded by an adhesive having a temperature equal to or higher than 0 ° C. and equal to or lower than the softening temperature of the resin film, and a step of performing a heat treatment at a temperature equal to or higher than the softening temperature of the adhesive and equal to or lower than the melting point of the resin film. And a method for producing a resin-coated container. 2. The method according to claim 1, wherein the heat treatment is performed at a temperature from the melting point of the resin film.
The method for producing a resin-coated container according to claim 1, wherein the temperature is lower than 0 ° C and lower than the melting point of the resin film.