Metallized film for capacitor

Abstract

The invention discloses a metallized film for a capacitor. The metallized film comprises a plastic film bottom layer and a metal coating. The metal coating comprises a zinc coating which directly makes contact with the plastic film bottom layer, an aluminum coating located on the surface of the zinc coating and an aluminum oxide dense protection layer located on the surface of the aluminum coating. The material of the plastic film bottom layer is a polymer formed by homopolymerization of a monomer composition containing polar groups or copolymerization of multiple monomer compositions in which at least one monomer composition contains polar groups. Corona discharge processing is conducted on the surface, making contact with the metal coating, of the plastic film bottom layer under the protection of mixed gas of inert gas and hydrogen. According to the metallized film for the capacitor, the metal layer aluminum-zinc-aluminum three-coating-film structure of an existing metallized film for the capacitor can be simplified. The invention further discloses a machining process of the metallized film for the capacitor.

Description

technical field [0001] The invention relates to a metallized film for capacitors and a processing technology thereof, and belongs to the technical field of manufacturing metallized films for capacitors. Background technique [0002] At present, the metallized films used in the manufacture of film capacitors are composite zinc-aluminum metallized films. Aluminum-plated metallized film has good adhesion, and the production process is easy to handle, but aluminum-plated metallized film is easily oxidized in the air to form a dense oxide layer with aluminum oxide as the main component. Although this oxide layer can prevent The metallized film is further oxidized, but when working under AC high voltage and high current, the oxide layer will lead to a rapid decline in the capacity of the capacitor; for this reason, a layer of zinc on the basis of the metallized film can be well prevented. The inner aluminum layer forms an oxide layer, so that the capacity of the capacitor does no...

AI Technical Summary

Problems solved by technology

Aluminum-plated metallized film has good adhesion, and the production process is easy to handle, but aluminum-plated metallized film is easily oxidized in the air to form a dense oxide layer with aluminum oxide as the main component. Although this oxide layer can prevent The metallized film is further oxidized, but when working under AC high voltage and high current, the oxide layer will lead to a rapid decline in the capacity of the capacitor; for this reason, a layer of zinc on the basis of the metallized film can be well prevented. The inner aluminum layer forms an oxide layer, so that the capacity of the capacitor does not drop rapidly, but the metallized film galvanized layer is more reductive, and the rate of oxidation in the air is faster, and the zinc oxide formed by oxidation has a fluffy The structure of the metallized film is difficult to prevent further oxidation, so the metallized film galvanized layer is not only difficult to handle during processing, but also easily leads to accidents of heating or even breakdown of the capacitor; for this reason, it is also necessary to coat the metallized film with aluminum and zinc A layer of aluminum is plated on the basis to protect the galvanized layer of the metallized film