H. C. Starck, Gmbh & Co Kg

H.c. Starck Gmbh

Karlheinz Reichert

Christoph Schnitter

Josua Löffelholz

Hady Seyeda

Walter Bludssus

Oliver Thomas

Rüdiger Wolf

R&uuml;diger Wolf

Leonid Natan Shekhter

Terrance B Tripp

Leonid L Lanin

Udo Sulkowski

Josua L&ouml;ffelholz

Falko Schlenkrich

Uwe Bohmke

Gisbert Ebeling

Wolfgang Simon

Christine Rawohl

Harald Troger

Harald Kroger

Detlef Breithaupt

Heike Biermann

Joachim Vieregge

Rudiger Wolf

Josua Loeffelholz

Ruediger Wolf

Disclosed herein are capacitors having an anode based on niobium and a barrier layer based on niobium pentoxide, at least the barrier layer having a content of vanadium and process for their preparation and use.

Capacitor powder

A valve metal powder by is prepared by a particular set of sequential steps that involves the use of precursor having preformed morphology. The method by which the valve metal is prepared includes a stabilization step that results in the valve metal powder having secondary and tertiary structures that each corresponds to the secondary and tertiary structures of the precursor. Also described is a method of producing solid electrolyte capacitors that include the valve metal powder of the present invention.

Valve metal powders

Process for producing a valve metal powder by producing a precursor of desired morphology, converting the precursor into an oxide of the valve metal, stabilizing the structure of the oxide by heat treatment and reducing the stabilized oxide while retaining the morphology. Valve metal powders obtainable in this way, in particular comprising spherical agglomerates with a mean agglomerate size of 10&#x2013;80 &#x3bc;m, preferably 20&#x2013;40 &#x3bc;m, and use of these valve metal powders to produce solid electrolyte capacitors.

Valve metal powders and process for producing them

An electrolyte capacitor containing a niobium anode, a niobium oxide barrier layer, a semiconducting cathode and an electrolyte is described, where the niobium oxide barrier comprises a least one metal from the group consisting of Al, Si, Ti, Zr, Mo, W, Y and Ta.

An anode is described that has a niobium-based barrier layer, which includes a niobium metal core, a conducting niobium suboxide layer and a dielectric barrier layer of niobium pentoxide.

Niobium-based capacitor anode

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

The present invention discloses a tantalum powder for capacitors and a method for making said tantalum powder wherein agglomerated tantalum powder is produced by means of thermal agglomeration of starting tantalum powders in the presence of hydrogen.

Tantalum powder, method for producing same powder and sintered anodes obtained from it

The invention relates a tantalum powder free of alkali and fluorine, which for a relatively small primary particle size has comparatively large secondary particles and is suitable for producing capacitors with a specific charge of between 100,000 and 180,000 &mgr;FV/g at specific residual currents of less than 2nA/&mgr;FV.

The present invention relates to novel organometallic compounds of the general formula M(OH).sub.y (A).sub.V (B).sub.z, wherein M is Ti(IV), Nb(V) or Ta(V) and x +y+z=5 for Nb and Ta and x+y+z=4 for Ti and A means an alkoxide ligand of diols and/or glycol monoethers and B is a carboxylate ligand of fatty acids of a carbon chain length of C.sub.6 -C.sub.19, and to processes for the production and use thereof.

Nb, Ta and Ti salt solutions and processes for the production and use

The present invention relates to a process for removing antimony from hydrofluoric acid solutions which contain Ta/Nb and have an acidity of &gt;18 N, by addition of a base metal reducing agent to the solution and heating at 40 to 60.degree. C. for 4 to 8 hours.

Process for removing antimony from hydrofluoric acid solutions which

Phase-pure, crystalline tungstates of general composition Me(II)WO.sub.4, where Me(II)=Co, Ni, Zn, Pb, Mg, Ca, Sr and/or Ba. These are prepared by wet mixing tungsten components (preferably ammonium paratungstate or metatungstate) with corresponding sponding Me(II) oxides and used, preferably, in making perovskites and X-ray intensifier phosphors.

Metal tungstates and method of preparing them and their use

Highly reactive metal niobates and/or metal tantalates of the general formula Me(II)A.sub.2 O.sub.6 or Me(III)AO.sub.4, a method for the preparation thereof, their further processing to form perovskites of the general formula X(B'B')O.sub.3 wherein X signifies Pb and/or Ba, B' signifies Mg, Fe, Co, Ni, Cr, Mn, Cd, Ti, Zr and/or Zn and B' signifies Nb and/or Ta, as well as these perovskites are provided through the present invention. An additive of Li, Na and/or K is provided to the niobates/tantalates in 0.1 to 20 mol-%.

Metal niobates and/or tantalates, their preparation and perovskites

Process for the production of phase-pure highly reactive lead metal niobates of perovskite structure corresponding to the general formula Pb.sub.3 Me(II)Nb.sub.2 O.sub.9 or Pb.sub.2 Me(III)NbO.sub.6, where Me.dbd.Mg, Fe, Co, Ni, Cr, Mn, Cd, Cu and/or Zn, in which perovskite intermediates are formed from corresponding salt solutions, separated off, dried and calcined at temperatures of 500 to 1000.degree. C.

Growing community of inventors

Wolfenbüttel, Germany

Karlheinz Reichert