Abstract: The performance of capacitor-grade tantalum powder that is vacuum packaged is enhanced. Preventing contact with air reduces the quantity of oxygen that passes through the oxide film and dissolves in the substrate. Lower oxygen in the powder can lower DC leakage in the capacitor made from the powder. Over a 4-month period, vacuum/argon packaging reduces oxygen pick-up in a 50K-class powder by over 200 ppm compared with the same powder stored in conventional packaging.
Type:
Grant
Filed:
June 7, 1995
Date of Patent:
June 27, 2000
Assignee:
H.C. Starck, Inc.
Inventors:
Ross W. Simon, Katsuo Iwabuchi, Hirobumi Ishikawa, Dieter Behrens
Abstract: The present invention relates to cobalt metal agglomerates consisting of peanut-shaped primary particles with average particle sizes in the range from 0.5 to 2 .mu.m, to a process for the production thereof and to the use thereof.
Type:
Grant
Filed:
April 24, 1998
Date of Patent:
February 1, 2000
Assignee:
H.C. Starck GmbH & Co. KG
Inventors:
Astrid Gorge, Katrin Plaga, Armin Olbrich, Dirk Naumann, Wilfried Gutknecht, Josef Schmoll
Abstract: The present invention relates to cobalt metal agglomerates consisting of peanut-shaped primary particles, to a process for the production thereof and to the use thereof.
Type:
Grant
Filed:
November 21, 1997
Date of Patent:
January 18, 2000
Assignee:
H.C. Starck GmbH & Co. KG
Inventors:
Astrid Gorge, Juliane Meese-Marktscheffel, Dirk Naumann, Armin Olbrich, Frank Schrumpf
Abstract: A method for the preparation of sodium tungstate by the oxidation of hard metal scrap and/or heavy metal scrap in a molten salt mixture of hydroxide and sodium sulfate.
Abstract: Powder metallurgy production of Ta10W alloy affording properties comparable to melt derived Ta10W, but at higher yields and lower costs, is enabled by blending component powders of minus 325 mesh and sintering at 2,400.degree. C. in three sinter steps and utilizing a slow ramp up in the first sinter step and cold isostatic pressing prior to the first sinter step and isostatic press densification in conjunction with at least the first sinter step.
Abstract: 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.
Type:
Grant
Filed:
June 3, 1997
Date of Patent:
June 22, 1999
Assignee:
H.C. Starck GmbH & Co. KG
Inventors:
Karlheinz Reichert, Wolfgang Simon, Harald Troger, Gisbert Ebeling
Abstract: The present invention relates to a process for removing antimony from hydrofluoric acid solutions which contain Ta/Nb and have an acidity of >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.
Type:
Grant
Filed:
April 30, 1997
Date of Patent:
June 1, 1999
Assignee:
H.C. Starck GmbH & Co KG
Inventors:
Walter Bludssus, Karlheinz Reichert, Uwe Bohmke
Abstract: Method of preparing metal disulfides of the general formula(Sn.sub.x Me.sub.1-x)S.sub.2,whereinMe represents one or more of the elements Ti, Mo, Fe, Cr, Ta, Nb, Mn, Bi, W and Cu, andx can have values between 0.5 and 1,by mixing Sn, alone or with Me and/or Me sulfides, with a superstoichiometric quantity of S and reacting the same together, in the presence of halide compounds, in an exothermic reaction in an inert atmosphereand the further processing the disulfide product thereof to form dimetal trisulfides.
Abstract: The present invention relates to a process for the production of pure ammonium metallates of the metals W, Mo, V, Cr and Re, wherein alkaline metal salt solutions are adjusted to a pH value in the range from 5 to 9 by reaction with CO.sub.2, these metal salt solutions are passed through an anion exchanger in carbonate form, wherein, in addition to the alkali metal carbonate solution, the metallate form of the ion exchanger is formed, the ion exchanger is then washed until free of alkali and is then eluted by means of aqueous ammonia to form ammonium metallate solutions and the anion exchanger in the OH form, wherein the anion exchanger is converted into the carbonate form by means of CO.sub.2 treatment and is recycled.
Abstract: 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.
Type:
Grant
Filed:
May 9, 1995
Date of Patent:
February 23, 1999
Assignee:
H.C Starck GmbH & Co. KG
Inventors:
Walter Bludssus, Karlheinz Reichert, Udo Sulkowski
Abstract: A process for drawing wire employing a lubricant composed of perfluorocarbon compounds having the general formula C.sub.n F.sub.2n+2. Such fully fluorinated carbon compounds exhibit a very high degree of thermal and chemical stability, due to the strength of the carbon-fluorine bond. Further, because the compounds are fully fluorinated, and therefore do not contain chlorine and bromine, they have zero ozone depletion potential (ODP). Further, because the PFCs are photochemically non-reactive in the atmosphere, they are not precursors to photochemical smog and are exempt from the federal volatile organic compound (VOC) definition.
Abstract: The present invention relates to pastes for the coating of substrates, consisting of powdery materials present in liquid dispersion from the group of the metals, metal compounds and/or metal alloys and/or boron and/or carbon, methods for manufacturing them and their use.
Type:
Grant
Filed:
October 16, 1996
Date of Patent:
March 3, 1998
Assignee:
H.C. Starck GmbH & Co., KG
Inventors:
Bruno E. Krismer, Uwe Thies, Peter Ladstatter, Rudolf Hunert
Abstract: 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-%.
Abstract: Cobalt/cobalt oxide powder having the composition Co.sub.x (CoO).sub.1-x, where x is from 0.02 to 5, and a process for its production and use in nickel hydroxide electrodes for secondary batteries to enhance capacity.
Abstract: Process for the production of pure tungsten and/or molybdenum solutions from sources, such as alkaline decomposition solutions, which are contaminated with tantalum, niobium, titanium, aluminium, tin, arsenic, phosphorus and/or silicon, by application of a three stage purification process of pH reduction, anion exchange and membrane electrolysis.
Abstract: Microcrystalline bodies based on .alpha.-Al.sub.2 O.sub.3 are made by drying sub-micron powders, press compacting and shock sintering at an intermediate sinter temperature range of 1,300.degree. to 1,550.degree. C., i.e. bringing the compact up to such range in under 60 seconds, preferably under 10.
Type:
Grant
Filed:
January 24, 1996
Date of Patent:
September 9, 1997
Assignee:
H.C. Starck GmbH & Co. KG
Inventors:
Paul Moltgen, Pirmin Wilhelm, Josef Schmoll
Abstract: Manganese(III)-containing nickel(II) hydroxide powders produced by coprecipitation carried out by dropping an acidified metal salt solution containing Ni.sup.+2 and Mn.sup.+3 ions into a feed of constant pH value, such that manganese(III) is incorporated into the nickel(II) hydroxide lattice, thereby preventing disproportionation into separate phases and improving performance characteristics of secondary battery electrodes manufactured therefrom.