US2305849A

US2305849A - Metallized condenser paper

Info

Publication number: US2305849A
Application number: US232696A
Authority: US
Inventors: Dorn Walter
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-10-04
Filing date: 1938-09-30
Publication date: 1942-12-22
Anticipated expiration: 1959-12-22

Description

Dec, 22, 1942, w. DORN I 2,305,849

METALLIZED CONDENSER PAPER Filed Sept. 50, 1938 Patented Dec. 22, 1942 METAILIZED CONDENSER PAPER Walter Dom, Stuttgart, Germany; vested in the Alien Property Custodian Application September 80, 1938, Serial No. 232,698

In Germany October 4, 1937 60lalms.

when using metal paper for manufacturing condensers in which the faulty points inthe dielectric become innocuous by the burning out of the metal coating around the faulty points. it is necessary to ensure that th energy liberatedon burning out in the event of a puncture is not too large, since otherwise mechanical destruction can occur in the winding. The results of experiments have shown that by using metals with fairly large conductivity, it is possible to make the metal layers so thin, for instance 0.1;, that the burning out process requires a particularly small energy. Very good results are obtained with silver or copper. Still better suited are aluminum or magnesium since-these metals, with reference to the units of weight, have the smallest specific resistance of all metals which are still suillciently stable. It is thus especially advantageous to use aluminum or magnesium, as a metal coating in manufacturing condensers of the said type.- Zinc and cadmium are also suitable,

However, an obstacle to the use of these metals is their extraordinary tendency to oxidation, whereby difllculties arise in the production of the electrical connections.

An object of the present invention is to provide a metallized dielectric material of the type described, in which the advantages of oxidisable metals such as aluminum, magnesium, zinc or cadmium can be realised without the accompany ing disadvantage of the said metals becoming oxidized. I v

- In the manufacture of condensers, according to the present invention a metallized paper isv used having a coating of a base metal in electrically conductive connexion with an adjacent coating-of noble metal, that is to say, having a relatively high resistance to oxidation, e. g. silver 009F By this means a layer or a more noble metal is'disposedalong the edge of the paper band which later serves for the connexion. Copper is especially to be recommended on account of its good conductivity, its fairly noble properties and low cost. a y

It is of advantage to vaporise this copper layer on in vacuodirectly after the application or the aluminum or magnesium without the bands being previously brought into contact with the air. The magnesium or aluminum has then not yet become coated with a him of oxide and combines very readily with the copper to form a magnesium bronze or aluminum bronze. It is suitable to gradually at the point of combination with the noble metal and to allow the copper layer to commence gradually. 80 that the resulting metal thickness also remains approximately constant.

at the transition layer. By gradually" is intended to be understood in this process a width of transition of at least 1 mm. It is appropriate to provide the vaporising point for the copper directly behind that for the aluminum, the vaporlsing nozzles being appropriately allowed to run at an acute angle at the point of the transition layer.

In the drawing, the edge part of a paper band metallized according to the process just described is illustrated in a greatly enlarged section perpendicular to the edge and to the surface. The paper hand is shown by i, the base metal coating by 2 and the nobler metal coating by 3.

I declare that what I claim is:

i. la an electrostatic condenser, a metallized paper comprising a paper layer carrying an adherent metallic coating of substantially uniform thickness comprising a strip of metal highly reclstant to oxidation selected from the group consisting of silver, and copper, lying parallel to a margin 02 the paper layer, and a strip of base metal selected from the group consisting of magnesium, aluminum. cadmium, and zinc, lying next to the-highly resistant metal strip on the side away from said margin of the paper, said highly resistant and base metal strips having their meeting edges in continuous conductive connection with each other.

2. In an electrostatic condenser, a metallized 35 of zinc lying next to the noble metal strip on the side away from said margin of the paper, said silver and zinc strips having their meeting edges in continuous conductive connection with each other.

a. In an electrostatic condenser, a metallized paper comprising a paper layer carrying an adherent metallic coating of substantially uniform thickness comprising a strip of copper lying parallel to a margin of the paper layer, and a strip of sine lying nextto the-noble metal strip on the allow the layer of the base metal to terminate side away irom said margin of the'paper, said copper and zinc strips having their meeting edges in continuous conductive connection with 'each other.

4. In an electrostatic condenser, a metallized paper comprising a paper la'yer carrying an adherent metallic coating of substantially uniform thickness comprising a strip or copper lying parallel to a margin of the paper layer, and a strip of base metal selected from the group consisting of aluminum, magnesium, cadmium, and 'zinc,

. lying next to the copper strip on the side away from said margin of the paper, said copper and base metal strips having their meeting edges in continuous conductive connection with each other.

5. In an electrostatic condenser, a metallized band 01. fiexible dielectric material carrying an' adherent metallic coating of substantially uniform thickness comprising a strip of base metal selected from the group consisting of magnesium, aluminum, cadmium, and zinc, and a strip of metal relatively highly resistant to oxidation selected from the grou consisting of silver, and copper, said highly resistant metal strip formlocated between said zinc strip and at least one longitudinal edge of the band, said strips having their adjacent margins united by metal consisting of an alloy of the adjacent copper and zinc metals along a slope the plane of which meets the surface of said band in an acute angle.

WALTER DORN.