Abstract: Process for the production of a composite of metal oxides, according to which a metal alcoholate is hydrolysed in the presence of metal (hydr)oxide particles in order to convert the metal alcoholate into a metal (hydr)oxide gel enveloping the metal (hydr)oxide particles. Powders of a composite of metal oxides obtained by this process and ceramic materials obtained by sintering a powder of this type.
Abstract: A porous granular ceramic material has a granule size of from 1 to 5 mm, a bulk density of from 200 to 700 g/l, preferably 350 to 550 g/l, a porosity of from 50 to 80% v/v, preferably from 65 to 80% v/v, and a liquid absorbency of from 20 to 200%, preferably from 40 to 150%, of water based on the weight of the granular material. The material may be made by calcining a mixture of a clay and a particulate combustible material. The material is suitable for use as animal litter or as an industrial absorbent for liquids.
Type:
Grant
Filed:
February 20, 1991
Date of Patent:
January 5, 1993
Inventors:
Franz D. Kunst, Arthur F. Payne, Paul A. Wilkinson
Abstract: The present invention provides a method for improving the durability of cement-hydraulic substances, the method decreasing the dry shrinkage of cement-hydraulic-set substances such as concrete, mortar or related substances, and increasing resistance to a repetition of the freezing and thawing of the cement-hydraulic-set substances, by the use of terminal alkyletherified compounds or terminal alkylesterified compounds of polymers having --C.sub.2 H.sub.5 O-- and/or --C.sub.3 H.sub.6 O-- as a repetitive unit.
Abstract: A Group IIA metal-Group IIIA metal-silicon substantially homogeneous liquid alkoxide is prepared from a reaction mixture of a Group IIA metal, a Group IIIA metal, a silicon tetraalkoxide, and a liquid defined by the formula ROR' where R is an alkyl group and R' is hydrogen or an alkyl group. The alkoxide can then be hydrolyzed, azeotropically distilled, dried, milled, and calcined to produce a ceramic powder. Advantageously, the ceramic powder can be compacted and sintered at relatively low temperatures which enable it to be used in electrical applications where high sintering temperatures would be deleterious.
Type:
Grant
Filed:
May 6, 1991
Date of Patent:
December 22, 1992
Assignee:
Union Carbide Coatings Service Technology Corporation
Abstract: Preceramic polymers are prepared by mixing an organosilicon oligomer or polymer containing a multiplicity of Si--H and/or Si--N functional groups with a borane in an organic solvent for a sufficient time for the reactants to react, wherein the molar ratio of the organosilicon polymer repeat unit to borane is 15 or less.
Abstract: A ceramic green sheet which is fired to give a porous ceramic structure, and which is formed of a composition which principally consists of a ceramic powder, a binder, and a multiplicity of planar or elongate flakes which disappear upon application of heat, and which are oriented in the ceramic green sheet in a direction substantially parallel to opposite major surfaces of the green sheet. Also disclosed is an electrochemical element having a protective layer covering at least one electrode, which layer is prepared from the ceramic green sheet indicated above, and has a multiplicity of planar or elongate pores corresponding to the planar or elongate flakes included in the green sheet. A method of producing the electrochemical element is also disclosed.
Abstract: A process for preparing a nitridable silicon-containing material, which process includes (a) comminuting a slurry of silicon powder, water, at least one densification aid, including Al.sub.2 O.sub.3, and another densification aid, the comminuting performed to cause substantial chemical reaction between the silicon and the water; and (b) reducing the water content of the reacted slurry to form a dry mass. In another embodiment, at least one nitriding agent may be added to aid any nitridation which may be performed.
Abstract: This invention relates to the preparation of highly densified ceramic bodies by the pyrolysis of a mixture comprising a preceramic borosilazane, silicon carbide powder, and, optionally, a curing agent for the borosilazane. Such highly densified ceramic bodies can be prepared by sintering under pressure or by a pressureless sintering process.
Abstract: The invention relates to a novel sinterable ceramic powder, to its preparation and to its further processing to give a silicon nitride ceramic, and to this material itself and its use. The sinterable ceramic powder is produced by melting a polysilazane or dissolving it in an organic solvent, suspending a powdered sinter aid in this melt or solution, then pyrolyzing the melt, or the residue obtained after evaporation of the solvent, at 500.degree. to 1600.degree. C. in a protective gas atmosphere, the polysilazane eitherA) being obtainable by reacting at least one of the oligosilazanes of the formula (I) ##STR1## in which a, b, c and d are the mole fractions of the respective structural units and where 0.ltoreq.a.ltoreq.1, 0.ltoreq.b.ltoreq.1, 0.ltoreq.c.ltoreq.0.7, 0.ltoreq.d.ltoreq.0.7, 0.3.ltoreq.a+b, c+d.ltoreq.0.7 and n is approximately 2 to approximately 12, with at least one of the chlorosilanes R.sup.6 R.sup.7 SiCl.sub.2, R.sup.8 SiCl.sub.3, Cl.sub.2 R.sup.9 Si--CH.sub.2 CH.sub.2 --SiR.sup.9 Cl.sub.
Type:
Grant
Filed:
March 23, 1990
Date of Patent:
November 10, 1992
Assignee:
Hoechst Aktiengesellschaft
Inventors:
Marcellus Peuckert, Tilo Vaahs, Martin Bruck, Hans-Jerg Kleiner, Ralf Riedel, Martin Sehr, Gunter Petzow
Abstract: The invention provides an essentially layered lithium transition metal oxide compound and a method of making it. It comprises lithium cations, transition metal cations T and oxygen anions, the transition metal cations T having an average valency of from +3 to +4. It has its O anions arranged in layers in a substantially cubic-close-packed arrangement, with its Li cations being arranged in layers and its T cations occupying octahedral sites and being arranged in layers. Each layer of the Li cations is sandwiched between two layers of the O anions and each said layer of O anions is sandwiched between a said layer of Li cations and a layer of the T cations. 75%-99.8% of the T cations in the compound are located in the layers of T cations, and the remainder of the T cations are located in the layers of Li cations, the T cations being selected from Co cations and mixtures of Co and Ni cations.
Abstract: A method for producing a concrete with a controllable density, which at the density of 1200 kg/m.sup.3 has a compression strength of at least 3.5 MPa and after that linearly increases to at least 19 MPa at 2,000 kg/m.sup.3, characterized in mixing a base concrete mixture mainly consisting of cement and water with a porousity mixture mainly consisting of cement, water and a foaming agent so that the foaming agent constitutes at least approximately 5% by volume of the porousity mixture, and that the resultant mixture of the base concrete mixture and the porousity mixture is moulded in a conventional manner.
Abstract: A battery including a spare battery is provided in which the six cells conventionally used for the spare battery are decreased to three cells, thereby allowing the capacity of the main battery to be increased. No charger for the spare battery is required. The main battery comprises six cells connected in series, the first of the six cells having a capacity at least 10% higher than that the remaining three cells. A switch is used to connect the spare battery in parallel with the remaining three cells of the main battery.
Abstract: The invention provides a metallic composition and methods for making and using the same. In a preferred embodiment the metallic composition forms a conductor path and is bonded to a substrate of aluminum nitride. The metallic composition comprises Mo, Si, Cu and Mn. The Si may be present in the metallic composition as MoSi.sub.2. The metallic composition may be produced by firing a paste that has been applied to a substrate of aluminum nitride. The paste comprises an organic vehicle and a metallic powder. The metallic powder preferably comprises about 60% to about 90% by weight Mo, about 0.5% to about 15% by weight MoSi.sub.2, about 5% to about 20% Cu and up to about 20% by weight Mn.
Abstract: A conductive resin composition which has electrical conductivity and antistatic property, is excellent in heat resistance and processability, and comprises:(A) from 50 to 95% by weight of a polyphenylene ether resin,(B) from 50 to 5% by weight of a copolymer of a styrenic compound and an .alpha.,.beta.-unsaturated dicarboxylic acid imide compound,(C) from 5 to 30 parts by weight of a conductive carbon per 100 parts by weight of the sum of the resin (A) and the copolymer (B), and (D) from 1 to 20 parts by weight of a low molecular weight polystyrene per 100 parts by weight of the sum of the resin (A) and the copolymer (B).
Abstract: An improved casting composition utilizes an aqueous finely dispersed silica binder to provide reduced drying times and reduced cracking and explosion of troughs, runners and other containment equipment designed for use by the iron and steel industry. The composition is prepared by mixing 8-14% by weight of the aqueous silica binder with 55-90% by weight of a refractory base material and up to 35% by weight of silicon carbide. Preferably, the composition will also include 5-10% by weight of calcined alumina, 1-10% by weight of microsilica, and 0.02-1% by weight of a setting agent. Troughs and runners manufactured from the composition also exhibit increased strength and improved resistance to oxidation, corrosion and erosion.
Type:
Grant
Filed:
November 21, 1991
Date of Patent:
September 15, 1992
Assignee:
Magneco/Metrel, Inc.
Inventors:
Subrata Banerjee, Charles W. Connors, Jr.
Abstract: A process for manufacturing an organic silazane polymer which comprises: reacting ammonia with a mixture of organosilicic compounds (I) and (II) wherein R is a methyl group, an ethyl group, or a phenyl group, and R.sub.1 is a hydrogen atom or a vinyl group, and X is a chlorine or a bromine atom; then polymerizing the thus obtained silazane compound in the presence of an alkali catalyst.
Abstract: A Group IIA metal-Group IIIA metal-silicon substantially homogeneous liquid alkoxide is prepared from a reaction mixture of a Group IIA metal, a Group IIIA metal, a silicon tetraalkoxide, and a liquid defined by the formula ROR' where R is an alkyl group and R' is hydrogen or an alkyl group. The alkoxide can then be hydrolyzed, azeotropically distilled, dried, milled, and calcined to produce a ceramic powder. Advantageously, the ceramic powder can be compacted and sintered at relatively low temperatures which enable it to be used in electrical applications where high sintering temperatures would be deleterious.
Type:
Grant
Filed:
March 9, 1989
Date of Patent:
August 18, 1992
Assignee:
Union Carbide Coatings Service Technology Corporation
Abstract: There is disclosed a sintering arrangement for enhancing the removal of carbon from multilayer ceramic substrate laminate during the sintering thereof. A multilayer ceramic substrate laminate having metallic lines and vias is provided with a reducible metal oxide in close proximity to the substrate laminate. The multilayer ceramic substrate laminate contains a polymeric binder which upon heating depolymerizes into carbon. The substrate laminate is sintered in an atmosphere which is reducing with respect to the reducible metal oxide and which is oxidizing with respect to the carbon.
Type:
Grant
Filed:
September 11, 1991
Date of Patent:
August 18, 1992
Assignee:
International Business Machines Corporation
Inventors:
Lester W. Herron, Sarah H. Knickerbocker, Ananda H. Kumar, Govindarajan Natarajan, Srinivasa S. N. Reddy
Abstract: A coating composition comprising a colloidal silica, an organohydroxysilane, a partial condensate of the organohydroxysilane and a liquid medium containing ethylene glycol monobutyl ether in an amount of at least 20% by weight, which is applied to a substrate, shows excellent properties such as storage stability, workability for coating or painting, heat resistance, surface hardness, chemical resistance, abrasion resistance, scratch resistance, stain resistance and weather resistance.
Abstract: A shaped body is disclosed which comprises substantially amorphous, silicon nitride-based ceramic containing Si, N and B as essential components and O, C and H as optional components in amounts providing the following atomic ratios:N/Si: 0.05 to 2.5,B/Si: 0.01-3,O/Si: 2.0 or less,C/Si: 1.5 or less, andH/Si: 0.1 or less.