JPH04127413A - Laminated aluminum material for electrolytic-capacitor case use - Google Patents

Abstract

PURPOSE:To obtain a laminated aluminum material whose close contact property, insulating property and corrosion-resistant property of an organic film are excellent by a method wherein, after one side or both sides of an aluminum material have been coated with an adhesive which contains an olefin-based copolymer and an aziridine compound, an olefin-based resin layer is laminated and this assembly is heated at the melting point or higher and at the decomposition temperature or lower of the adhesive layer and the resin layer. CONSTITUTION:An olefin-based adhesive is used for a resin layer which is laminated on one side of both sides of an aluminum material. An olefin-based copolymer as a main agent is used for an adhesive; the range of an aziridine compound is set at 0.5 to 15% with reference to 100 pts.wt. of the olefin-based copolymer. In order to enhance a close contact property after a drawing working operation, a heating treatment is executed to heat the adhesive layer to a temperature at the melting point or higher and at the decomposition temperature or lower of the adhesive layer and the resin layer after a laminating operation. The laminated aluminum material for electrolytic-capacitor case use is excellent in its corrosion-resistant property and its insulating property and is excellent also in its close contact property by the drawing working operation and in its close contact property at the working temperature of an electrolytic capacitor.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a laminate material for an electrolytic capacitor case, and more specifically, to T5 adhesion after deep drawing an aluminum material for a capacitor case.

Concerning laminated aluminum materials for electrolytic capacitor cases with excellent insulation and corrosion resistance.

(Prior art and problems to be solved) Electrolytic capacitor cases are usually made of aluminum and are used by stacking a large number of capacitor foils inside. In some cases, a film with excellent insulating properties is installed to prevent a short circuit even if the capacitor foil touches the case. In this case, an organic film is provided as an insulating film on the inner surface of the case.

In addition, the outer surface of the case is covered with a resin cover to prevent malfunctions due to contact with other electrical parts and to display the rated voltage and capacity. In this case, it is necessary to provide an organic film as an insulating film on the outer surface of the case as well.

Furthermore, a method has been proposed in which the outer organic film is colored in order to clearly display the rated voltage and capacity when miniaturized.

Conventionally, methods for forming an organic film on an aluminum material include a resin coating method and a resin lamination method, but each method has the following problems (1) to (3).

■ Baking method for coating resins such as epoxy, polyester, PVC, and acrylic: In this case, adhesion during drawing is good, but thick coating is difficult, insulation is insufficient, and electrolytic capacitors The corrosion resistance against the electrolyte used is insufficient, and some coating components are eluted into the electrolyte, resulting in problems such as deterioration of the electrolyte.

■Fluorine-based resin coating baking method: Corrosion resistance against electrolytes is good because resin with excellent chemical resistance is used, but fluorine-based resins have insufficient adhesion and have the problem of peeling during drawing. There is.

■A method of dry laminating an olefin resin layer with incyanate adhesive: In this case, the corrosion resistance and insulation properties are good, but the adhesion is insufficient, and moreover, it does not peel off during drawing. However, there is a problem in that the film shrinks and peels due to the heat of around 100°C that electrolytic capacitors have.

As mentioned above, all conventional organic film forming methods are insufficient in adhesion, insulation, or corrosion resistance.

Furthermore, regarding the #@ edge property, it is required that there is little deterioration due to heat when bonding the capacitor to the printed circuit board with solder.

The present invention was made in view of the pressing circumstances, and
The object of the present invention is to provide a laminated aluminum material for electrolytic capacitors that has excellent organic film adhesion, insulation properties, and corrosion resistance after being processed for electrolytic capacitor cases.

(Means for Solving the Problems) In order to achieve the above object, the present inventors focused on the fact that the method using film lamination has excellent insulation properties,
The present invention was developed as a result of extensive research in order to find a way to obtain a laminate material with excellent adhesion and corrosion resistance.

That is, in the present invention, 0.5 to 100 parts by weight of the olefin copolymer is added to one or both sides of the aluminum material.
After applying an adhesive containing 15% of an aziridine compound to a dry thickness of 5 to 25 μm, an olefin resin or polyamide resin layer with a thickness of 10 μm or more is laminated, and then the adhesive The object of the present invention is to provide a laminated aluminum material for electrolytic capacitor cases, which is heated to a temperature above the melting point of the agent layer and the resin layer and below the decomposition temperature, and has excellent adhesion, insulation properties, and corrosion resistance.

Further, in another aspect of the present invention, the adhesive layer is colored by containing either 0.5 to 10% of a dye or 3 to 15% of a pigment based on 100 parts by weight of the adhesive. This is a characteristic feature.

The present invention will be explained in more detail below.

(Function) As the resin layer laminated on one or both sides of the aluminum material, an olefin resin or polyamide resin film that has good corrosion resistance against electrolyte and is ductile is used.In this case, the adhesive is this resin. An olefin adhesive is used that has good adhesion to the layer and aluminum material and has good corrosion resistance to electrolytes.

The adhesive used is a mixture of an olefin copolymer as a main ingredient and an aziridine compound as a curing agent. Various olefin copolymers can be used; for example, acrylic acid-modified polyethylene, acrylic acid-modified polypropylene, acrylic acid ester maleic anhydride polyethylene copolymer, ethylene vinyl acetate copolymer, etc. are preferably used. can.

The blending ratio of the above-mentioned base resin and curing agent is such that if the curing agent is less than 0.5% with respect to 100 parts by weight of the base resin, the crosslinking density of the adhesive will be insufficient, and the adhesion and corrosion resistance will be insufficient; If the content exceeds , the crosslinking density of the adhesive will become too high,
This is not preferable because it reduces adhesion. Therefore, the amount of the aziridine compound is in the range of 0.5 to 15% based on 100 parts by weight of the olefin copolymer.

If the thickness of the adhesive layer is less than 5 μm after drying after being applied to the aluminum material, the adhesion between the resin layer and the aluminum material will be insufficient, and even if it is applied with a thickness exceeding 25 μm, the effect will be saturated. This is economically wasteful. Therefore, the thickness of the adhesive layer after drying is in the range of 5 to 25 μm.

Suitable examples of the polyamide resin film include so-called nylon 6, nylon 66, nylon 11, nylon 12, nylon polymer alloys, nylon elastomers, nylon 6.12 copolymers, nylon 6.12.66 copolymers, and the like. Can be used.

If the thickness of the resin layer is less than 10 μm, the insulation properties will be insufficient, so it is necessary to set the thickness to 10 μm or more, and preferably 20 μm or more.

In order to improve the adhesion after drawing, it is necessary to perform a heat treatment after lamination to a temperature above the melting point of the adhesive layer and the resin layer and below the decomposition temperature. If the heat treatment temperature is lower than the melting point, the adhesive will not be sufficiently cured, and the adhesion between the adhesive layer and the resin layer will be insufficient.
The adhesion after drawing is poor. Further, if the temperature is higher than the decomposition temperature, the adhesion after drawing decreases, which is not preferable.

Furthermore, if colored laminates are to be obtained, it is possible for the adhesive to contain dyes or pigments in predetermined amounts.

In this case, the amount of dye added is preferably less than 0.5% based on 100 parts by weight of the adhesive, since the color after painting will be pale, and if it is added more than 10%, the effect of improving the adhesion of the adhesive will be reduced. do not have. Therefore, the amount of dye added is in the range of 0.5 to 10% with respect to 100 parts by weight of the adhesive.

The amount of pigment added is 3 parts by weight per 100 parts by weight of the adhesive.
If the content is less than 15%, the color after coating will be pale, and if it is more than 15%, the effect of improving the adhesion of the adhesive will be reduced, which is not preferable. Therefore, the amount of pigment added is in the range of 3 to 15% based on 100 parts by weight of the adhesive.

It goes without saying that various aluminum and aluminum alloys suitable for this type of use can be used as the aluminum material.

(Example) Next, examples of the present invention will be shown.

Loss of JLflL Using the adhesive and resin film shown in Table 1, each lamination thickness was laminated on one side of an aluminum material (JISlloo, thickness 0.30 mm). Next, a laminated aluminum material was obtained by subjecting it to the heat treatment shown in the same table.

The obtained laminated aluminum material was drawn at a drawing ratio of 2.5 to form a case with a diameter of 30+n+ and a height of 33111111.

These cases were examined for adhesion, corrosion resistance, and #7@edge properties after processing, as well as adhesion when heated to 100° C. after processing. Further, the withstand voltage was measured after contacting the sample with the laminate side facing up for 1 minute in a molten solder bath at 270°C. The results are shown in Table 2.

The corrosion resistance was evaluated based on the state of elution of film components into the electrolyte. In addition, the insulation property is 5g/QCuS after drawing process.
It was immersed in an O4.5H20.5g/QH (l aqueous solution for 3 minutes at room temperature, and evaluated by observing the state of Cu precipitation.

As is clear from Table 2, each of the examples of the present invention has excellent corrosion resistance and insulation properties, and also has excellent adhesion not only during drawing but also when heated at 100°C after drawing. ing.

On the other hand, all of the comparative examples are insufficient in either corrosion resistance, insulation, adhesion during drawing, or adhesion when heated at 100° C. after processing.

[Left space below] Aluminum material (JIS 1100, thickness 0.30++) using the adhesive and resin film shown in Table 3.
+m) was laminated on one side with various types. Next, a laminated aluminum material was obtained by subjecting it to the heat treatment shown in the same table.

The obtained laminated aluminum material was drawn at a drawing ratio of 2.5 to form a case with a diameter of 30 nv+ and a height of 33+ wm.

These cases were examined for adhesion, corrosion resistance, and insulation after processing, as well as adhesion when heated to 100° C. after processing. Further, the withstand voltage was measured after contacting the sample with the laminate side facing up for 1 minute in a molten solder bath at 270°C. The results are shown in Table 4.

Note that the evaluation of corrosion resistance and adhesion was the same as in Example 1.

As is clear from Table 4, each of the invention examples has excellent corrosion resistance and insulation properties, and is also excellent in adhesion not only during drawing but also when heated at 100°C after drawing. ing.

On the other hand, all of the comparative examples are insufficient in either corrosion resistance, insulation, adhesion during drawing, or adhesion when heated at 100° C. after processing.

[Blank 1 (Effects of the Invention) As detailed above, the laminated aluminum material for electrolytic capacitor cases according to the present invention has excellent corrosion resistance and insulation properties, as well as good adhesion through drawing and a high resistance to the operating temperature of electrolytic capacitors. It has excellent adhesion and excellent heat resistance when soldered, making it suitable for small capacitor cases.

Patent applicant: Kobe Steel, Ltd. Same Totoku Paint Co., Ltd. Representative Patent Attorney Takashi Nakamura

Claims (3)

[Claims] (1) Apply an adhesive containing 0.5 to 15% of an aziridine compound to 100 parts by weight of the olefin copolymer to one or both sides of the aluminum material to a thickness of 5 to 25% after drying.
Adhesion characterized by coating the adhesive layer to a thickness of 10 μm or more, then laminating an olefin resin layer with a thickness of 10 μm or more, and then heating the adhesive layer and the resin layer to a temperature above the melting point and below the decomposition temperature, Laminated aluminum material for electrolytic capacitor cases with excellent insulation and corrosion resistance. (2) The laminated aluminum material for an electrolytic capacitor case according to claim 1, wherein a polyamide resin is used in place of the olefin resin. (3) The adhesive layer is 0 parts by weight based on 100 parts by weight of the adhesive.
．． The laminated aluminum material for an electrolytic capacitor case according to claim 1 or 2, which is colored by containing either 5 to 10% of a dye or 3 to 15% of a pigment.