Bright gold electroplating bath and method of electroplating bright gold

Claim 1

A BRIGHT GOLD ELECTROPLATING BATH, COMPRISING: AN AQUEOUS SOLUTION OF AN ALKALI METAL GOLD CYANIDE, SAID GOLD BEING PRESENT IN CONCENTRATIONS OF FROM ABOUT 2 G/L TO SATURATION: BETWEEN 4 MG/ AND 40 GRAMS/L CALCULATED AS THE METAL, OF AN ALLOYING AGENT SELECTED FROM ONE OR MORE MEMBERS OF THE GROUP CONSISTING OF COBALT AND NICKEL, SAID AGENT BEING ADDED TO SAID BATH AS A COMPLEX WITH AT LEAST AMINOGUANIDINE AND CHELATING PHOSPHONIC ACID; THE CONCENTRATION OF SAID AMINOGUANIDINE BEING FROM ABOUT 2 G/L TO 50 G/L. AND SAID PHOSPHONIC ACID BEING PRESENT IN SUFFICIENT QUANTITY TO COMPLEX SAID ALLOYING AGENT; AS ADDITIONAL CONDUCTING AND BUFFERING AGENTS, ONE OR MORE BATH SOLUBLE PHOSPHATES; THE PH OF SAID BATH BEING BETWEEN 3 AND 6, AND THE CONCENTRATION OF SAID CONDUCTING AND BUFFERING AGENTS BEING APROPRIATE IN THE PRESENCE OF THE REMAINING BATH COMPONENTS TO ADJUST THE BATH SPECIFIC GRAVITY TO A DESIRED LEVEL OF FROM ABOUT 6* TO UP TO 20* BAUME, SAID LEVEL BEING ABOVE THAT WHICH WOULD BE ACHIEVED IN THE ABSENCE OF SAID AGENTS.

Claim 9

A method for electroplating bright deposits of gold alloyed with a metal selected from the group consisting of cobalt and nickel, comprising: preparing a complex of a metal selected from the group consisting of cobalt and nickel, with at least aminoguanidine and a chelating phosphonic acid; preparing an aqueous electroplating bath of an alkali metal gold cyanide, together with said complex, and as conducting and buffering agents one or more bath soluble phosphates; the pH of said bath being between 3 and 6, and said gold being present in concentrations of from about 2 g/l to saturation, said complEx including in said bath from about 4 mg/l to 40 g/l of said alloying metal; the concentration of said aminoguanidine being from about 2 g/l to 50 g/l, and said phosphonic acid being present in sufficient quantity to complex said alloying metal; and the concentration of said conducting and buffering agents being appropriate in the presence of the remaining bath components to adjust the bath specific gravity to a desired level of from about 6* up to 20* Baume, said level being above that which would be achieved in the absence of said agents; and electrolyzing said aqueous bath to yield the desired electroplating.

Claim 10

A method for electroplating bright deposits of gold alloyed with a metal selected from the group consisting of cobalt and nickel, comprising: preparing a complex of a metal selected from the group consisting of cobalt and nickel, with at least aminoguanidine and a chelating phosphonic acid; preparing an aqueous electroplating bath of an alkali metal gold cyanide, together with said complex, and as conducting and buffering agents one or more bath soluble phosphates; the pH of said bath being between 3 and 6, and said gold being present in concentrations of from about 2 g/l to saturation, said complEx including in said bath from about 4 mg/l to 40 g/l of said alloying metal; the concentration of said aminoguanidine being from about 2 g/l to 50 g/l, and said phosphonic acid being present in sufficient quantity to complex said alloying metal; and the concentration of said conducting and buffering agents being appropriate in the presence of the remaining bath components to adjust the bath specific gravity to a desired level of from about 6* up to 20* Baume, said level being above that which would be achieved in the absence of said agents; and electrolyzing said aqueous bath to yield the desired electroplating.