US821626A - Process of making metallic films or flakes. - Google Patents

Description

7 To all whom it may concern.-

UNITED STATES PATENT OFFICE.

THOMAS A: EDISON, OF LLEW ELLYN- 'PARK, NEW JERSEY, ASSIGNOR TO EDISON STORAGE BATTERY COMPANY, OF WEST ORANGE, NEW JER- SEY, A CORPORATION OF-NEW JERSEY.

Specification of Letters Patent.

Patented May 29, 1906.

Application and seat so. not. Serial-Ho. 262.982.

wherein the active mass, such as nickel h droxid, is admixed with insoluble metal '0' scales or films for the purpose of insuring contact between the active particles themselves and between the active particles and the in closing pockets .or other metallic supports. As I have pointed-out, these metallic scales or films are formed, preferably, of cobaltnickel alloy, since by using this material the characteristically good contact'obtained with cobalt is secured, while the presence of the nickel prevents the cobalt from suffering more than a mere surface oxidation.

'My present invention relates to an improved process by which metallic scales or films can be obtained at low cost, either of co- I balt or of nickel, or of a cobalt-nickel alloy.

I nickel and j thousandth of an inch in thickness and I a pearing practically as a mere blush upon tl ie copper srrface) This zinc is deposited'on the copper or nickel in a solution of zinc sulfate or other zinc salt in the usual wa The cathode thus prepared is now washe and in a suitable electrolytic bath a film of the desiredmetal or metals is plated on the electrodeposited layer of zinc. When either cobalt or nickel is to be deposited a suitable ammomum-sulfate solution of that metal and cogbalt or nickel anodes are used. When both metals are to be simultaneously deposited, a cobalt-nickel ammonium-sulfate solution is employed with se arate cobalt. and nickel anodes. In the la ter case the current from each anode will be sore ated as to secure the desired proportion o deposit thereof. I .havefound in practice that good results are or oil, the latter be]? secured when the deposited alloy is composed of about seventy er cent. of cobalt and thirty percent. of nic el, although these proportfons may be very widely varied. The cobelt or nickel or cobalt-nickel film thus def posited upon the superposed film of zinc is made extremely thin generally about .0002 inch in thickness. he cathode is now immersed in a dilute acid (sulfuric, hydrochloride, or acetic) which does not sensibly attack the cobalt or nickel or cobalt-nickel film, but results in a relatively rapid dissolution of the zinc to thereby free the insoluble film from the'metal base. The metallic zinc .in being thus attacked by the weak acid solution results in the formation of hydrogen gas, which in esca ing eifects a separation or detachment 0 the nickel or cobalt or alloy film. I find, furthermore, that by carrying on the process described the film of cobalt or nickel or alloy thereof becomes detached in the form of small flakes or scales, which naturally assume a curved or curled shape-a phenomenon especially characteristic of cobaltand which afterbreakin up andsizing by screens are thereforein the best condition for admixture with the active material. These films are now washed and annealed by heating them in a hydrogen atmosphere to a red heat, which treatment effects a very perfect cleaning of tlie surfaces. Films or scales obtained in this way may be applied to the active material in any suitable manner, examples of which are indicated in my concurrent applications for Letters'Patent. 4

In order to facilitate the stripping of the deposited film of cobalt or nic el or allo thereof, it may in some cases be desirable a ter the film or blush of zinc has been deosited-on the copper plate to immerse the atter in a solution-of wax or oil (such as solvent so that when dry the zinc enou h as not to e. prevent the roper eposition o the cobalt ;or nickel or a loy thereof by greatly facilitat .i thestripp operatlon. avmg-now escrlbed my invention, what I claim as new therein, and desire to secure by Letters Patent, is as follows:@

1. The process of making metallic films,

which consists in depositing a soluble metal on a cathode, then in electrodepositing a film of an'insoluble metal or metals thereon, and

. in finally dissolving the soluble metal to detach the insoluble film, substantially as set forth.

2. The process of making metallic films, which consists in depositing a soluble metal on a cathode, then in electrodepositing a film of insoluble metal or metals thereon and finally immersing the lated cathode in an acid-bath to attack t e soluble metal and separate the insoluble film, substantially as set forth.

3. The process of making metallic films, which consists in depositing a soluble metal on a suitable cathode, in electrodepositing an insoluble metallic film thereon, and in subj ecting the plated cathode to the effect of the acid which dissolves the insoluble metal and results in the evolution of gas to separate and detach the insoluble film, substantially as set forth.

4. The process of making metallic films,

which consists in de ositing a thin film of zinc on a suitable cat ode, in electrodepositing an insoluble film on the zinc, and in subjecting the plated cathode to dilute acid to dissolve the zinc and generate hydrogen gas,

as and for the purposes set forth.-

5. The process of making metallic films, which consists in depositing a'soluble metallic film on a-suitable cathode, in electrode ositmg thereon a thin film of metallic coba t or cobalt alloy and in dissolving the soluble metal to detach the insoluble film, substantially as set forth.

6. The process of making metallic films, which consists in de ositing a" thin film of zinc on a suitable cat ode, in electrodepositing thereon a thin film of cobalt or cobalt al- 10 and in subjecting the plated cathode to dilute acid to thereby dissolve the zinc and effect the separation of the insoluble film, substantially as setforth.

7. The process of making metallic films, which consists in depositing a soluble metallic film on a suitable cathode, in electrodepo siting thereon a thin film of metallic coba t or cobalt ,allo and in dissolving the soluble metal to etach the insoluble film, andfi'a finally annealing the separated film in a big drogen atmosphere, substantially as set fort 8. The process of making metallic films, which consists in de 'ositing a thin film of zinc'on a suitable cat ode, in electrodepositing thereon a thin film of cobalt or cobalt allo and in subjecting the plated cathode to dilute acid to thereby dissolve the zinc and effect the separation of the insoluble film, and v in finally annealing the separated film in a hydrogen atmosphere, as and for the pur-' poses set forth.

This specification signed and witnessed this 29th-d'ay of March, 1905.

- THOMAS A. EDISON. Witnesses:

FRANK L. DYER, ANNA R. KLEnM.