H.c. Starck Gmbh

Kemet Electronics Corporation

Nrc Corporation

Terrance B Tripp

Leonid Natan Shekhter

Leonid L Lanin

Howard V Goldberg

Anastasia M Conlon

Barbara L Cox

Malcolm Shaw

John Tony Kinard

Brian John Melody

David Alexander Wheeler

Karlheinz Reichert

Duane Earl Stenzinger

Oliver Thomas

Joachim Vieregge

Richard W Hildreth

Richard Hildreth

Leo G Gibbons

High purity refractory metals, valve metals, refractory metal oxides, valve metal oxides, or alloys thereof suitable for a variety of electrical, optical and mill product/fabricated parts usages are produced from their respective oxides by metalothermic reduction of a solid or liquid form of such oxide using a reducing agent that establishes (after ignition) a highly exothermic reaction, the reaction preferably taking place in a continuously or step-wise moving oxide such as gravity fall with metal retrievable at the bottom and an oxide of the reducing agent being removable as a gas or in other convenient form and unreacted reducing agent derivatives being removable by leaching or like process.

Metalothermic reduction of refractory metal oxides

The metal oxide surface coating of an anodized valve metal may be made conductive under certain conditions so that conductive coatings can be electrolytically deposited on the surface of the oxide. When a dry polar aprotic electrolyte solution is used at a reduced temperature and a relatively high field is applied, the oxide ceases to be insulative. The process is reversible, meaning that there is no permanent change in the oxide.

Method of passing electric current through highly resistive anodic oxide films

Electrolytic capacitor powder substrates are provided of refractory metal nitrides to reduce instability at a substrate-oxide (as formed) interface whereby the resultant capacitor sensitivity to hear, bias and frequency is reduced.

Capacitor substrates made of refractory metal nitrides

A process for producing sintered pellets made from blends of refractory metal and refractory metal nitride powders were found to have a higher fraction of intra-agglomerate pores than those made from the refractory metal or refractory metal nitride alone resulting in improved capacitor grade powders, anodes and finished capacitors therefrom. The pellet porosity and total intrusion volume maximizes when the mixture is in the 50-75 W/W % refractory metal nitride range. The total pellet pore surface area was found to be relatively independent of refractory metal nitride concentration above 50%. A substrate consisting of a 50/50 or 25/75 W/W % refractory metal/refractory metal nitride powder mixture should produce solid capacitors with higher capacitance recovery and lower ESR.

Tantalum and tantalum nitride powder mixtures for electrolytic capacitors substrates

Metal powder Ta and/or Nb, with or without one or metals from the group Ta, Nb, Ti, Mo, W, V, Zr and Hf, is made in a fine powder form by reduction of metal oxide by contact with a gaseous reducing agent, preferably an alkaline earth metal, to near complete reduction, leaching, further deoxidation and agglomeration, the powder so produced being sinterable to capacitor anode form and processable to other usages.

Metal powders produced by the reduction of the oxides with gaseous magnesium

Metal nitride compound powder substrate for capacitor anodic oxide film and the substrate interface therebetween, characterized, relative to un-nitrided analogs, by reduced temperature bias and frequency dependencies of capacitance, the substrate-anodic oxide interface being substantially insensitive to heating compared to the un-nitrided analog.

Metal powder from the group Ta, Nb, Ti, Mo, W, V, Zr, Hf preferrably Ta or Nb, is made in a fine powder form by reduction of metal oxide by contact with a gaseous reducing agent, preferrably an alkaline earth metal, to near complete reduction, leaching, further deoxidation and agglomeration, the powder so produced being sinterable to capacitor anode form and processable to other usages.

Method for producing tantallum/niobium metal powders by the reduction of their oxides with gaseous magnesium

Tantalum anode pellets or tantalum powders are treated to remove carbon content (mostly attributable to binders used in pressing the powders to pellet form and/or sintering of the pellets) by an aqueous leach at 50.degree.-200.degree. F. in lieu of the conventional complex distillation/decomposition methods.

Removal of binder from Ta products

Fine tantalum powder of high surface area, high capacitance, low leakage and high breakdown voltage is produced by sodium reduction of highly dilute fluotantalate salt charges at high reaction temperatures and stepwise additions of the sodium reducing agent in a time-series of substantially even weight slugs added over the whole course of the reduction reaction to a melt of the charge and using the small exotherm of reduction provided by each slug as a temperature control factor.

Tantalum production via a reduction of K2TAF7, with diluent salt, with

Tantalum powders of capacitor grade are provided, containing interacting silicon and phosphorous dopants to effect low D.C. leakage of electrolytic capacitors having anodes made from such powders, with anodic formation at low temperatures (40.degree.-60.degree. C.), consistent with high capacitance.

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Westborough, MA, United States of America

Terrance B Tripp