JPH0399411A - Film capacitor - Google Patents

Abstract

PURPOSE:To obtain excellent damp-proof property, workability and stabilized withstand voltage characteristics by a method wherein polyphenylene sulfide containing 2-10% low-molecular (tetramer or lower) components is used as the polyphenylene sulfide film which becomes a dielectric, and the interlayer adhesive force of a metallized film is strengthened. CONSTITUTION:The title film capacitor is formed by laminating and winding a polyphenylene sulfide film, at least one side of which is metallized. A polyphenylene sulfide film, having 2-10% low-molecular (tetramer or lower) components, is used. The above-mentioned low-molecular material performs as a bonding agent on the surface of the film. Such poly-phenylene sulfide films are coated with Al on one side by vapor deposition, and laminated to form a film capacitor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to film capacitors widely used in electrical equipment.

2. Description of the Related Art Conventionally, film capacitors of laminated type and wound type are known. Polyphenylene sulfide film is used as the dielectric material of these laminated or wound type film capacitors.

Problems to be Solved by the Invention However, in film capacitors using polyphenylene sulfide film as a dielectric as described above, the interlayer adhesion of the metallized film is weak, resulting in poor moisture resistance and workability during the manufacturing process. In addition, the weak adhesion between the layers of the metallized film creates an air layer, which causes discharge deterioration and causes variations in withstand voltage.

The present invention solves these conventional problems by making the interlayer adhesion of the metallized film strong, providing excellent moisture resistance, workability during the manufacturing process, and stable pressure resistance. The purpose is to provide a film capacitor that can be obtained.

Means for Solving the Problems The film capacitor of the present invention is a dielectric polyphenylene sulfide film in which the proportion of low molecular weight phenylene sulfide tetramer or less is 2% to 1%.
It is characterized by using 0%.

Here, phenylene sulfide having a low molecular weight of less than a tetramer is present on the surface of the film and serves as an adhesive. If the proportion of low molecular weight phenylene sulfide tetramer or less is less than 2%, it will not contribute significantly to the interlayer adhesion of the metallized film, and if it exceeds 10%, the electrical and chemical properties as a dielectric material will deteriorate. Needless to say, it deteriorates.

Function of the present invention C. The low molecular weight of phenylene sulfide, which is less than a tetramer, contained in the polyphenylene sulfide film acts as an adhesive, strengthens the interlayer adhesion of the metallized film, and has excellent moisture resistance. In addition, it is possible to obtain a film capacitor that has good workability during the manufacturing process and also has stable voltage resistance.

EXAMPLE Hereinafter, a multilayer film capacitor according to an example of the present invention will be described with reference to the drawings.

Prepare polyphenylene sulfide films with a thickness of 2 μm in which the proportion of low molecular weight phenylene sulfide tetramers or less is 0%, 2%, 6%, and 10%, and deposit AIl on one side of each film. Laminated Lfg
A multilayer film capacitor with a capacity of 0.01μF. The interlayer adhesion strength and external pressure breakdown of the metallized film were measured using three-point deflection measurements for each laminated film capacitor. The results are shown in FIGS. 1 and 2. As can be seen from FIGS. 1 and 2, the stronger the interlayer adhesion of the metallized film, the smaller the variation in external pressure failure.

In addition, although Al was used as the vapor-deposited metal in the examples, metals other than Al may be used.

Further, a wound type film capacitor according to another embodiment of the present invention will be described with reference to the drawings.

Prepare polyphenylene sulfide films with a thickness of 2 μm in which the proportion of low molecular weight phenylene sulfide tetramers or less is 0%, 2%, 6%, and 10%, and deposit Al on one side of each film. A wound type film capacitor with a capacitance of 0.1 μF was manufactured by winding. Moisture resistance test of each wound film capacitor was conducted at 60 tl;
The results obtained under the condition of 95% RH are shown in FIG. Third
As can be seen from the figure, the low molecular weight of tetramer or less is 2%~
A wound film capacitor using a 10% film exhibits more stable capacitance changes in a moisture resistance test than a wound film capacitor using a 0% film.

This is because the adhesive force distribution inside the element is uniform.

In the examples, Al was vapor-deposited on one side of the film, but Al may be vapor-deposited on both sides, or a metal other than Al may be used as the vapor-deposited metal.

Effects of the invention By using phenylene sulfide in which the proportion of low molecular weight of tetramer or less is 2% to 10%, this low molecular weight acts as an adhesive and strengthens the interlayer adhesion of the metallized film. and has good workability during the manufacturing process.
In addition, a fill capacitor with excellent moisture resistance and stable voltage resistance can be realized.

[Brief explanation of drawings]

Fig. 1 is a characteristic diagram of interlayer adhesion of a metallized film measured by three-point deflection measurement of a laminated film capacitor according to an embodiment of the present invention, and Fig. 2 is a characteristic diagram of the same laminated film capacitor during an external pressure breakdown test. FIG. 3 is a characteristic diagram showing the capacitance change during a moisture resistance test of a wound film capacitor according to another embodiment of the present invention.

Claims (1)

[Claims] A film capacitor made by laminating or winding polyphenylene sulfide films metallized on at least one side, using a polyphenylene sulfide film in which the proportion of low molecular weight phenylene sulfide tetramer or less is 2% to 10%. A film capacitor characterized by: