High charge, low leakage tantalum powders

A tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage containing a total added carbon plus nitrogen plus sulfur content in an amount from about 150 ppm to 3,000 ppm total contained C+N+S, with a minimum sulfur content of 75 ppm on a tantalum metal weight basis.

A tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage containing a total added carbon plus nitrogen plus sulfur content in an amount from about 181 to 1632 ppm contained C+N+S on a tantalum metal weight basis.

In a method of preparing a tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage, the improvement which comprises the step of adding to said powder a material containing at least two elements selected from the group consisting of carbon, nitrogen and sulfur in an amount from about 100 to 10,000 ppm total contained additive on a tantalum metal weight basis.

In a method of preparing a tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage, the improvement which comprises the step of adding to said powder a carbon plus nitrogen plus sulfur-containing material in an amount from about 181 to 1632 ppm total contained carbon plus nitrogen plus sulfur content on a tantalum metal weight basis.

In a method of preparing a tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage, the improvement which comprises the step of adding to said powder a carbon plus nitrogen plus sulfur-containing material in an amount from about 100 to 10,000 ppm total contained carbon plus nitrogen plus sulfur content, with a minimum sulfur content of 50 ppm on a tantalum metal weight basis.

In a method of preparing a tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage, the improvement which comprises the step of adding to said powder a carbon plus nitrogen plus sulfur-containing material in an amount from about 100 to 10,000 ppm total contained carbon plus nitrogen plus sulfur content, with a minimum sulfur content of 50 ppm on a tantalum metal weight basis, the said material being added to said tantalum powder by reacting said tantalum powder at elevated temperatures with hydrocarbon, nitrogen and sulfur-containing gases.

In a method of preparing a tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage, the improvement which comprises the step of adding to said powder carbon and sulfur-containing material in an amount from about 100 to 10,000 ppm total contained carbon plus sulfur content, with a minimum sulfur content of 50 ppm on a tantalum metal weight basis, the said material being added to said tantalum powders by reacting said tantalum powder at elevated temperatures with hydrocarbon and sulfur-containing gases.

In a method of preparing a tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage, the improvement which comprises the step of adding to said powder nitrogen plus sulfur-containing material in an amount from about 100 to 10,000 ppm total contained nitrogen plus sulfur content with a minimum sulfur content of 50 ppm on a tantalum metal weight basis, the said material being added to said tantalum powder by reacting said tantalum powder at elevated temperatures with nitrogen and sulfur-containing gases.

In a method of preparing a tantalum powder for electrodes in electrolytic capacity with improved specific capacity and low direct current leakage, the improvement which comprises the step of adding to said powder a carbon plus nitrogen-containing material in an amount from about 100 to 10,000 ppm total contained carbon plus nitrogen content, the said material being added to said tantalum powder by reacting said tantalum powder at elevated temperatures with hydrocarbon and nitrogen gases.

A tantalum powder for electrodes in electrolytic capacitors with improved specific capacity and low direct current leakage containing additives of at least two selected from the group consisting of carbon, nitrogen and sulfur in an amount from about 100 to 10,000 ppm total additives.