JPS6142407B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves applying an impregnating agent to a dielectric synthetic material foil, and then depositing said dielectric foil together with a dielectric synthetic material foil or metal foil that has been metallized.
The present invention relates to a method for manufacturing capacitor rolls by winding without a hygroscopic intermediate layer.

The following methods are known for impregnating foil capacitors: (a) After being wound, the capacitor roll is impregnated in a vacuum container. This method is relatively time consuming and interrupts the capacitor manufacturing process.

(b) German Patent Application No. 2403125 discloses applying an impregnating agent to both sides of the dielectric foil during winding.

This can be done by spraying or passing the foil through a bath containing the impregnating agent. Such impregnation methods run the risk of trapping air between the dielectric foil and the impregnating agent layer, thereby causing ionization and rendering the device unusable. Moreover, it is not easy to provide relatively thin impregnating agent layers by such methods.

C. German Patent Application No. 2108988 discloses impregnating strips of hygroscopic paper and processing this together with dielectric foil to form capacitor rolls. However, the additional paper layer increases the size of the resulting capacitor roll.

The object of the present invention is to provide a simple impregnation treatment of dielectric foils without an additional hygroscopic intermediate layer when manufacturing capacitor rolls, and to provide a finished product to be manufactured from the capacitor rolls thus obtained. The purpose is to ensure that the capacitor manufacturing process is not adversely affected.

To this end, the present invention applies an impregnating agent to a stock roll of dielectric synthetic material foil at approximately 0.01 mmHg.
(0.01 Torr) and then the dielectric foil is pulled out and then rolled together with a metallized dielectric composite foil or metal foil without a hygroscopic intermediate layer. do.

The impregnation of the stock roll of dielectric synthetic material foil is carried out prior to starting the actual production of the capacitor roll. As a result of such a vacuum impregnation process, a very thin air-free impregnating agent layer is formed between adjacent foils of the foil roll. Therefore,
A capacitor roll can be manufactured by a conventional method from the foil roll impregnated in this manner.

That is, in a capacitor winding machine, two or more dielectric foils and two or more metal foils (or metallized dielectric foils) are transferred from a stock roll onto a central take-up pin. or metallized foil) are rolled together so that they are alternately overlapping each other. These foils are wound in a staggered manner so that the metal foil (or metallized foil) protrudes on one end of the roll and alternately the dielectric foil extends on the other end of the roll. It's crowded. When these foils reach the desired length, they are cut and end pieces are attached to the resulting rolls. An end face is formed by depositing a metal layer by vapor deposition, a lead wire is attached to this, and a case is attached to the produced roll.

The invention will be illustrated by the following example.

Capacitor (8μ) wrapped in polyester foil
The polyester foil rolls, ie stock rolls, required to produce two sheets of polyester foil and two sheets of 5μ aluminum foil were heat treated in an empty vacuum vessel at a temperature of 50-60° C. for 10-20 minutes. During this time, the silicone oil used as an impregnating agent was degassed in a storage container evacuated to 0.5 mmHg (Torr). The foil roll was then evacuated to 0.01 mmHg (Torr) within the vacuum vessel for 30 minutes. The vacuum vessel was then filled with previously degassed silicone oil. The stock roll was removed from the impregnation bath after 20-30 minutes.

A capacitor roll thus produced and drawn using the metal foil in conjunction with the drawn dielectric foil was conventionally formed and then compared to a capacitor roll using unimpregnated polyester foil. The dielectric breakdown strength of the capacitor roll using polyester foil impregnated by the method of the present invention was 2430V, while the dielectric breakdown strength of the capacitor roll using non-impregnated polyester foil was 1725V. The breakdown strength of a corresponding capacitor roll using unimpregnated 12μ polyester foil was 2400V. This indicates that 8μ foil impregnated by the method of the present invention has a dielectric breakdown strength similar to that of unimpregnated 12μ foil.

Also, the number of weak spots (the number of electrical break-throughs that occur through the foil when a test voltage of 1800 V is applied) of the dielectric foil was significantly reduced by impregnation treatment according to the method of the present invention.

For example, silicone oil or wax can be used as impregnating agent. The dielectric foil can also be made from polypropylene, polyester, polycarbonate or polystyrene. Dielectric foils can be metallized. Alternatively a separate metal foil can also be used. Capacitors produced by the method of the invention have a higher capacitance than capacitors impregnated by known methods due to the lower thickness of the intermediate impregnated layer, and also exhibit a significantly greater increase in capacitance than non-impregnated capacitors. The reason for this is, for example, that the dielectric constant of silicone oil is 2.5.

Claims (1)

[Scope of Claims] 1 A stock roll of dielectric composite material foil is impregnated with an impregnating agent in a vacuum of about 0.01 mmHg (0.01 Torr), and then the dielectric foil is pulled out and then metallized. A method for producing a capacitor roll, characterized in that it is wound together with a material foil or a metal foil, without a hygroscopic intermediate layer. 2. A stock roll of dielectric synthetic material foil is first heated in a vacuum container to a temperature of 50-60°C, and then said vacuum container is heated to approximately 0.01 mmHg (0.01 Torr).
and then filling said vacuum vessel with degassed impregnating oil and exposing said stock roll to said impregnating oil for at least 15 minutes.
The method described in section.