US1935630A - Process of electrodepositing indium and indium and silver - Google Patents

Description

Patented Nov. 21, 1933 PROCESS OF ELECTRODEPOSITING IND AND INDIUM AND SILVER Daniel Gray, Oneida, N. Y., assignor to Oneida Community, Limited, Oneida, N. Y., a corporation of New York No Drawing. Application May 11, 1927, Sam No. 190,653. Renewed August 9, .1932

Claims.

This invention relates to a process of electrodepositing indium, and more particularly indium and silver, for the production, in either case, of tarnish-resisting products, either in the 5 form of finished articles, except for polishing, etc., or in the form of raw materials which may be used for various purposes including that of fabrication into finished articles.

I have observed in the use of alkaline baths from or through which indium, alone or together with silver, is to be plated, that after a time a compound containing the indium is precipitated fromthe bath, rendering the bath valueless for the purpose of electro-depositing indium.

I have discovered, as the result of various experiments, that this may be efiectively prevented by the introduction into the bath of an organic compound of an acid nature which will effect the retention of the indium in solution and thus cause it to be properly plated.

Various organic compounds of an acid nature may be used, such as glycine, cyanuric acid, abietic acid, adipic acid, acetyl m-aminobenzoic acid, acetyl p-aminobenzoic acid, acetaldehyde sodium bisulphite, m-aminobenzoic acid, so long as the compound used is one which, like glycine for example, will remedy the difl'iculty referred to without, at the same time, injuriously affecting the bath.

Such agent or agents may be used where indium alone is plated, or where indium and silver are simultaneously plated, and where the indium or indium and silver are plated from the bath, in which case an insoluble anode is used, or through the bath from anodes of indium or indium and silver. Where the two metals are simultaneously plated through the bath I prefer to use an anode consisting of an alloy or intimate mixture of the two metals instead of an anode of each.

In the following description the process will be described specifically in connection with the plating of indium through the bath and the plating of indium and silver through the bath by the use of such an alloy anode of indium and silver.

PROCESS 1 Indium plating Potassium cyanide 15 ozs. avoir. Glycine '7 ozs. avoir.

Water 1 gallon Current density about .035 amperes and upwards per square inch at the cathode. The cathode and an anode of indium being immersed in the bath, current will be passed through the bath from the anode in order to efiect a partial solution of the anode and thereby introduce indium into the bath in sufiicient quantity to give a suitable deposit on further electrolysis.

Pnoorzss 2 IndiumSilver plating A bath such as that just described is prepared 5 and an anode alloy or intimate mixture of indium and silver is immersed in the bath. Current is then passed through the bath from the anode to eifect a partial solution of the anode and thereby introduce both indium and silver in sumcient 7 quantities to give a suitable deposit of both metals on further electrolysis.

This process may also be used with two anodes, one of indium and the other of silver.

It may also be used for plating indium or indium and silver from the bath, which for that purpose will be made up with the indium or indium and silver as ingredients thereof. In that case an insoluble anode will be used, for example, one of carbon or platinum.

What is claimed is:

1. A process of electro-depositing indium which comprises the steps of immersing an article to be plated as the cathode in a prepared bath, said bath comprising 1 gallon of water, 15 oz. potassium cyanide, and 7 oz. glycine, or equivalent thereof selected from the group: cyanuric acid, abietic acid, adipic acid, acetyl m-aminobenzoic acid, acetyl p-aminobenzoic acid, acetaldehyde sodium bisulphite, m-aminobenzoic acid, immersing an anode of indium in said bath, and passing a current of about .035 amperes and upwards per square inch at the cathode to deposit indium on said article.

2. A process of electro-depositing indium which comprises the steps of immersing an article to be plated as the cathode in a prepared cyanide bath containing a material selected from the group: glycine, cyanuric acid, abietic acid, adipic acid, acetyl m-aminobenzoic acid, acetyl p-aminobenzoic acid, acetaldehyde sodium bisulphite, m-aminobenzoic acid, immersing an anode of indium in said bath, and passing a current therethrough to deposit indium on said article.

3. A process of electro-depositing indium-silver alloy which comprises the steps of immersing an article to be plated as the cathode in a prepared cyanide bath containing a material selected from the group: glycine, cyanuric acid, abietic acid, adipic acid, acetyl m-aminobenzoic 5. In the process of electro-depositing indium and silver simultaneously, the steps which comprise immersing an article to be plated as the cathode in a prepared cyanide bath containing glycine, immersing an anode of indium and silver in said bath, and passing a current therethrough to deposit indium and silver on said article.

DANIEL GRAY.