JPH02305422A - Metallized plastic film capacitor - Google Patents

Abstract

PURPOSE:To manufacture the compound dielectric coated layers in high dielectric constant without deteriorating the electric characteristics etc., by a method wherein compound dielectric coated layers composed of polyphenylene oxide, inorganic fine powder and organic peroxide are provided. CONSTITUTION:Compound dielectric coated layers 4 composed of polypropylene oxide, inorganic fine powder and an organic peroxide are formed on both sides or one side of both side metallized plastic films 2 leaving electrode leading-out parts on both sides in the width direction and then laminated or wound around so as to form metallicon electrodes 5 on both sides. That is, the organic peroxide is contained in the compound dielectric composed of polyphenylene oxide and the inorganic powder in excellent electric characteristics and thermal resistance as the material for the dielectric coated layers 4 so that the organic peroxide may be decomposed by the Joule's heat in the shortcircuit current and reacted to an evaporated metal to form an insulator. Accordingly, the self-heating capacity can be increased as well as the compound dielectric coated layers 4 in high dielectric constant can be formed. Through these procedures, the title capacitor can be miniaturized without deteriorating both electric characteristics and coating workability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to metallized plastic film capacitors used in electrical circuits of electronic equipment, information equipment, etc.

Conventional technology In recent years, as electronic devices have become lighter, thinner, shorter, and more sophisticated,
As the demand for smaller size and higher performance of electronic components increases, it is becoming an urgent need to address these issues in metallized plastic film capacitors as well.

A conventional metallized plastic film capacitor will be explained below using drawings.

FIG. 1 shows the structure of a conventional laminated metallized plastic film capacitor. In this figure, reference numeral 1 denotes a composite metallized film constituting a capacitor, in which electrodes 3 are formed on both sides of a dielectric film 2 by vacuum deposition, and electrodes 3 are formed on both sides of the dielectric film 2 in the width direction. A dielectric coating layer 4 is provided on the other parts except for the lead-out part. The required number of composite metallized films 1 thus constructed are laminated, and metallicon electrodes 5 are formed on both end faces in the width direction of this film laminate, thereby forming the desired metallized plastic film capacitor element. can get.

In conventional metallized plastic film capacitors, polyethylene terephthalate, which has excellent electrical properties, is mainly used as the dielectric film, and polyphenylene oxide is mainly used as the dielectric coating layer.

The dielectric constant of these materials is about 3 at most, and both the film and the coating have already been made thin to about 1 μm.

[Problems to be Solved by the Invention] It is known that the capacitance of a capacitor is proportional to the dielectric constant of the dielectric material and the area of the electrodes, and inversely proportional to the distance between the electrodes. Therefore, in order to downsize, that is, increase the capacitance per unit volume, it is necessary to use a dielectric with a high dielectric constant.
Also, it is necessary to make the dielectric thinner.

As a method of increasing the dielectric constant of dielectric materials, attempts have been made to combine organic polymer materials and inorganic fine powders.

In the case of metallized plastic film capacitors, a composite dielectric consisting of polyphenylene oxide, which has excellent electrical properties and heat resistance, and inorganic fine powder is coated on both sides or one side of a double-sided metalized plastic film, thereby reducing the size of the capacitor. is being attempted. However, the self-healing property unique to metallized plastic film capacitors is poor in composite dielectrics made of polyphenylene oxide and inorganic fine powder compared to dielectrics made only of polyphenylene oxide, and especially when an exterior is applied, oxygen is not supplied. , oxidation of the deposited metal during self-healing, and insulating properties due to the formation of a metal oxide cannot be achieved sufficiently.
Often, there was a problem that insulation resistance decreased during high-temperature load tests.

Regarding the thinning of the dielectric, as mentioned above, both the dielectric film and the coating layer have already been thinned to about 1 μm, and making the film thinner than this will lead to deterioration of electrical properties and reduced workability. We are in a difficult situation.

In order to solve the above-mentioned problems, the present invention aims to increase the dielectric constant of a coated dielectric material without significantly deteriorating electrical properties, reducing coating workability, or reducing reliability.
The purpose is to reduce the size of the capacitor.

Means for Solving the Problems In order to achieve the above object, the metallized plastic film capacitor of the present invention has a polyphenylene oxide film on both sides or one side of the double-sided metallized plastic film, with electrode extension parts left on both sides in the width direction. , forming a composite dielectric coating layer consisting of inorganic fine powder and organic peroxide,
It has a structure in which metallicon electrodes are formed on both sides by laminating or winding these.

Function: With this structure, an organic peroxide is incorporated into a composite dielectric made of polyphenylene oxide, which has excellent electrical properties and heat resistance, and an inorganic fine powder, as the material for the dielectric coating layer, and the Joule heat of short circuit current Since the organic peroxide is decomposed and reacted with the deposited metal to form an insulator, self-healing properties can be improved and a highly reliable composite dielectric coating layer can be formed.

The organic peroxide here is represented by the general formula R-00-R' (in this formula, R and R' are hydrogen or an organic group such as an alkyl group, a silyl group, an allyl group, or a benzoyl group). ,
The most suitable one is di-t-butyl peroxide, t
-Butyl peroxide.

There are t-butylperoxytriphenylsilane, cumene hydroperoxide, etc., as well as benzoyl peroxide, lauroyl peroxide, 2,5-dimethyl 2,5-di(t-butylperoxy)hexane-3
, dicumyl peroxide, t-bunalburoxy 2-
There are ethyl hexanautes, etc.

The amount of organic peroxide added is 0.1 to 10.0% relative to polyphenylene oxide. Good results are obtained at Owt%. If the amount added is less than 0.1 wt %, sufficient effects cannot be obtained, and if it exceeds 10.0 wt %, the volume change during humidification will be extremely increased.

Good results can be obtained when the amount of inorganic fine powder added is 20 to 80 wt. If the content is less than 20 wt %, a sufficiently high dielectric constant cannot be achieved, and if it exceeds 90 wt %, the capacitance change during humidification will be extremely increased.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to comparative examples. The metallized plastic film capacitor of this embodiment basically has the same general structure as shown in FIG. 1, so the explanation of the common parts will be omitted. In the embodiment of the present invention, as the dielectric coating layer 4,
A composite dielectric coating characterized in that the content of inorganic fine powder during coating is 20 to 80 wt%, and the content of organic peroxide is 0.1 to 10.0 wt% based on polyphenylene oxide. Use layers.

Table 1 shows the amount of TiO2 contained in the composite dielectric coating layer for Examples 1 to 6 of the present invention and Comparative Examples 1 to 5, 2,5-dimethyl 2,5-di(to-butylperoxy )
The amount of hexane-3 added is shown.

The coating liquid is polyphenylene oxide powder and 2,5-dimethyl 2,6-di(t-butylperoxy)hexane.
After uniformly dissolving 3 in trichlene, the average defective particle size was 0.
2 μm of T 102 was added, stirred and mixed, and further treated with a ball mill for 48 hours to uniformly disperse TiO2.

Note that Comparative Example 1 was obtained by uniformly dissolving polyphenylene oxide powder in trichlene.

These coating solutions were applied using a gravure coater onto a 2-μm-thick aluminum vapor-deposited double-sided metalized polyethylene terephthalate film, leaving electrode lead-out portions on both sides in the width direction, and after air drying, the coating was further heated at 120'C. By drying for 1 hour, a composite dielectric coating layer 4 having a thickness of 1 μm was obtained.

500 layers of the composite metallized film 1 obtained in this manner were laminated, heat-pressed at 130° C. and 2 Ky/ctd for 2 hours b, and zinc was metal sprayed onto the electrode lead-out portions on both sides to form the metallicon electrodes 5 described above. It has the same structure as shown in the drawing of 4. A capacitor with dimensions of Om x 4.6 g x 2.1 threshold was obtained.

Furthermore, the zinc provided at the electrode lead-out part of this capacitor was
．． 5 Weld a solder-plated iron wire with a diameter of Ql11, and apply epoxy resin of 0.4 to 0.6. A capacitor element was obtained by packaging with a thickness of .

Regarding this capacitor element, the capacitance and dielectric loss tangent at 20°C and I KHz, the initial insulation resistance at 50V DC, and the high temperature load test (100°C, 1D Ce
Insulation resistance defect rate after 3 V, 1000 Hr) and humidity resistance test (60°C, 90-9 s% RH, 500
The rate of change in capacity before and after Hr ) was measured. The results are shown in Table 1. The insulation resistance failure rate is expressed as a percentage of the insulation resistance at 50 VDC of 1×10 Ω or less in 50 samples. Other characteristic values are sample number 2
The average value at 0 is shown.

If the amount of T 102 added is less than 20 wt%, a high dielectric constant cannot be achieved. If it exceeds 80 wt%, a high dielectric constant can be achieved, but the capacitance change during humidification increases extremely.

2,6-dimethyl 2,6-di(t-butylperoxy)
If the amount of hexane-3 added is less than 0.1 wt% with respect to polyphenylene oxide, the insulation resistance after high temperature load will be DCsoV in the product with TzO2 added.
Among them, there were some with 1X109Q or less. 10.0
When the amount exceeded wt%, the change in capacity during humidification was extremely increased.

In this example, 2,6-dimethyl 2,5-di(t-butylperoxy)hexane was used as the organic peroxide.
3 was used, but similar effects can be obtained with other materials as long as they are organic peroxides. Furthermore, in this example, Ti○ was blended and dispersed as the inorganic fine powder, but in addition, B a T i O3゜S r T 1O3T P
Similar effects can be obtained using inorganic fine powders such as b TiO3 alone or in combination of two or more.

As described in detail of the invention, the metallized plastic film capacitor of the present invention has a composite dielectric coating layer composed of polyphenylene oxide, inorganic fine powder, and organic peroxide as a dielectric coating layer. As a result, a composite dielectric coating layer can be obtained in which the dielectric constant of the coated dielectric material is increased without causing significant deterioration of electrical properties, reduction in coating workability, or reduction in reliability.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts showing the structure of a general laminated metallized plastic film capacitor. 1... Composite metallized film, 2... Dielectric film, 3... Vapor deposited electrode, 4...
・Dielectric coating layer, 6...Metallicon electrode. Name of agent: Patent attorney Shigetaka Awano and one other person
−−− Neboku 1 genus Mei 已 film? --- is■j body film 3--1 vapor-deposited denmen bow 2--m 8N spitting
-m- Metallicon electrode Figure 1

Claims (3)

[Claims] (1) A composite dielectric coating layer consisting of polyphenylene oxide, inorganic fine powder, and organic peroxide is applied to both sides or one side of a double-sided metallized plastic film, leaving the electrode extension part on the image side in the width direction. 1. A metallized plastic film capacitor characterized in that metallicon electrodes are formed on both sides by laminating or winding the metallized plastic film capacitor. (2) The content of inorganic fine powder during coating of the composite dielectric coating layer is 20 to 80 wt%, and the content of organic peroxide is 0.1 to 10.0 wt% relative to polyphenylene oxide. The metallized plastic film capacitor of claim 1, characterized in that: (3) The inorganic fine powder is TiO_2, BaTiO_3, S
The metallized plastic film capacitor according to claim 1, characterized in that it is composed of rTiO_3 and PbTiO_3 alone or in combination of two or more thereof.