Abstract: A silicon carbide sintered body suitable for electrical discharge machining and a method for its manufacture are disclosed. The silicon carbide sintered body comprises 0.5-5% by weight of AlN, 0.5-3% by weight (as Ti) of a Ti compound, 0.5-8% by weight of C, 0-3% by weight (as B) of B or a B compound, and a remainder of substantially SiC. It has a volume resistivity at room temperature of not greater than 10 ohm-cm and a density of at least 90% of the theoretical density of SiC. The manufacturing method comprises shaping a mixture of the raw materials and sintering the shaped green body in a non-oxidizing atmosphere at a temperature of 2000.degree.-2300.degree. C.
Abstract: Compositions useful as pour point depressants, novel compounds within such compositions, and processes for making same, as well as lubricant oil compositions containing same, are disclosed. The novel compounds are encompassed by the general structural formula (I) ##STR1## wherein the Ar, Ar' and Ar" are independently an aromatic moiety containing 1 to 3 aromatic rings and each aromatic moiety is substituted with 0 to 3 substituents, (R) and (R') are independently an alkylene group containing about 1 to 100 carbon atoms with the proviso that at least one of (R) or (R') is CH.sub.2, and n is 0 to about 1000; with the proviso that if n is 0, then (R) is CH.sub.2 and each aromatic moiety is independently substituted with 0 to 3 substituents with one aromatic moiety having at least one substituent, the substituents being selected from the group consisting of a substituent derived from an olefin and a substituent derived from a chlorinated hydrocarbon.
Abstract: Particulate calcium carbonate or iron oxide pretreated with a fatty acid such as stearic acid or oleic acid is added to a cementitious product to improve its strength and resistance to water absorption and penetration. Dry, aqueous and nonaqueous methods of addition are employed.
Abstract: Water soluble precursors of ceramic compounds are emulsified in an organic fluid containing an organic surfactant. The emulsion is subsequently mildly heated at a pressure of about 0.05 atmospheres to remove the free water from the emulsion droplets. The resulting sludge consists of particles deriving from the dehydrated emulsion droplets. These particles may only be bound by the surfactant, all or most of the original organic fluid having been boiling off under low pressure. This sludge is then heated in a standard air atmosphere to char the surfactant, which char is to maintain the separation between the dried droplet-derived particles to prevent forming sintered or fused agglomerates thereof. With continued heating the transient char is subsequently burned off and the particles are calcined to controllably and simply produce a fine ceramic powder of spherical particles having a narrow size distribution and an average size in the particularly useful range of 0.1 micron to 1.0 micron.
December 29, 1986
Date of Patent:
June 7, 1988
Sprague Electric Company
Sidney D. Ross, Galeb H. Maher, Clinton E. Hutchins
Abstract: A method and apparatus for the thermal treatment of pulverulent raw material in the manufacture of cement clinker including passing raw material first through a multi-stage preheating treatment including cyclones arranged following one another, next passing the material through a reaction stack for calcination, then passing the material through a sintering kiln and thereafter through a clinker cooler, the exhaust air from the clinker cooler and the exhaust gas from the sintering kiln being passed parallel to the each other with the material discharged into conduits respectively carrying the discharged clinker cooler air and the sintering gases with burners in the conduits and the gases thereafter passing up through the reaction stack and then through a separator and into the sintering kiln.
Abstract: Dry cementitious compositions and methods for their application. The dry compositions do not have to be mixed with water but instead are poured, sprayed or troweled onto a substrate which contains a substantial excess of water than that necessary for the hydration of the materials.
Abstract: This invention relates to a chloride-free hardening accelerant for Portland cement which is active in particular at low temperatures and contains calcium nitrate, sodium nitrate, hexamethylenetetramine and sodium hydroxide. The accelerant is prepared by reacting the calculated amount of formaldehyde with calcium ammonium nitrate in aqueous solution at between room temperature and 55.degree. C. under alkaline conditions established with sodium hydroxide. After the reaction had ended this solution can be used directly as such or be converted into a powder by means of a suitable drying operation.
Abstract: A flowing concrete and a process of producing the same. A cement, water, aggregates, a superplasticizer and a segregation-controlling agent are kneaded into a base concrete having a water-cement ratio of about 35% or less, the segregation-controlling agent contained in an amount of about 0.02 to about 0.1 wt. %, based on the water and including a methylcellulose compound, and the superplasticizer contained in an amount of about 0.25 to about 0.6 wt. % based on the cement. Then, about 0.25 to about 0.6 wt. %, in terms of the solid, of a flowing agent based on the cement is added to the base concrete, the flowing agent including a sulfonic acid/formaldehyde high condensate and a polyvinyl alcohol. Further, the base concrete with the flowing agent is kneaded into the flowing concrete.
Abstract: This invention relates to improved aluminous cement/gypsum compositions that contain polymer latex emulsions or compounds to produce self-curing, crack-free, fast-setting, high early strength, high bonding, water resistant, durable, cementitious mixtures for finishing, coating, plastering, stucco, rigid insulation protection, topping, resurfacing, patching, motaring, tile grouting, concrete, and the like. In addition, this invention discloses a method for improving the properties and performance of aluminous cement/gypsum compositions by adding certain types, amounts and/or combinations of polymer latex emulsions or compounds with or without the addition of wet expansion and drying shrinkage inhibitors.
Abstract: An electronic substrate is provided in the form of a sintered body of polycrystalline alumina ceramic which further contains up to approximately 4% glass forming oxide selected from SiO.sub.2, MgO and ZrO.sub.2 along with about 0.4-2.0% refractory metal oxide to substantially reduce visible transmission in said substrate. In a preferred embodiment, said substrate comprises an elongated member of the ceramic material such as a flat layer which further includes a central cavity region housing an integrated circuit component such as a chip in which may be further provided with cover means for the central cavity in said member that can be formed with the same ceramic.
Abstract: A concrete composition for underwater use contains about 0.1 to 4% by weight based on cement content of a water soluble vinyl polymer containing vinyl units having sulfonic groups. The concrete composition is easy to mix and prevents separation of concrete composition constituents as it is laid under water.
Abstract: A dry composition including Portland cement, sand, fly ash Type F, with or without glass fiber, vinyl acetate-ethylene copolymer or equivalent powder form bonding agent, sodium salts of polymerized substituted benzoid alkyl sulfonic acids, or equivalent dispersing or emulsifying agent, and defoamer or antifoam agent or equivalent defoamer or antifoam agent, which is completely dry and controlled inplant.
July 15, 1986
Date of Patent:
May 3, 1988
Rockwall-Peerless Corp., Stucco and Mortar Products
Abstract: A composite comprised of a continuous matrix phase having a ceramic filler phase distributed therein is produced by shaping a mixture of ceramic filler and a solid constituent of the matrix into a compact and infiltrating the compact with a molten constituent of the matrix which combines with the solid constituent by dissolution and/or diffusion to produce the matrix in situ.
Abstract: A refractory binder including a tackifying agent. The tackifying agent is a montrorillorite clay. The binder is a chromium alumina phosphate mixture with a fluxing agent. The binder may also be a colloidal suspension of alumina, silica or zirconia with montmorillonite clay. The binder is used with refractory fiber to produce a monolithic layer.
Abstract: A hydraulic cement mix comprising a hydraulic cement, aggregate in an amount of up to 80% by weight based upon the total weight of said cement mix, sufficient water to effect hydraulic setting of the cement, and an air-entraining additive consisting essentially of a coconut fatty acid diethanolamine produced by reacting alkyl ester of coconut acid with diethanolamine and a capramide diethanolamide, said additive being in an effective amount whereby air will be entrained in said mix in an amount of 3% to 9% by volume of said mix.
June 3, 1987
Date of Patent:
April 12, 1988
Solvay Construction Materials, Inc.
Paul F. Gutmann, Donald R. Lane, Jose A. Melendez
Abstract: The invention has for its object: a fabrication process of hydraulic binders, characterized in that it consists:I. in preparing an active product according to a method comprising the following steps:selection of a raw material containing intimately mixed clay phases and calcium carbonate;heat treatment of said material at a temperature between 700 and 900 degrees C.;application during the heat treatment of a partial pressure of carbonic gas opposing the thermal dissociation of the calcium carbonate beyond that which combines with the clay phase;achievement of a simultaneous activation of the clay phases by dehydroxylation (pozzolanic activation) and of the clay-lime combinations with potential hydraulic properties, without formation of free lime;II. in mixing up to 95% of the active product so obtained with the corresponding complement to 100% of an activating product generating calcium hydroxyde.
Abstract: This invention provides a multi-step process for the preparation of ceramic fibers, such as ferrimagnetic spinel fibers which are useful in electromagnetic interaction shielding applications.The process involves subjecting a ceramic powder-filled hollow organic fiber to isostatic pressing, and then pyrolyzing and sintering the compacted fiber to yield a ceramic fiber.
Abstract: The slurries according to the invention contain: >18% NaCl; Na silicate and an agent of compatibility with magnesium consisting of H.sub.3 PO.sub.4 and HEDP diphosphonate.Thickening time is not affected by the presence or absence of salts of magnesium, up to 30% of bischofite equivalents. The rheology of the slurry and the compressive strength of the cement are also practically unaffected by magnesium contamination or the lack thereof.
Abstract: A highly refractive optical glass (n.sub.d .gtoreq.1.83) with high dispersion (v.sub.d .ltoreq.25) and very good chemical stability at relatively low density (.delta..ltoreq.3.5 g/cm.sup.3) consists of (in weight percent) SiO.sub.2 19-25, Na.sub.2 O 7-10, K.sub.2 O 4-7, Cs.sub.2 O 0-12, Cao 0.5-2.0, BaO 9-15, TiO.sub.2 25-30, ZrO.sub.2 0-6, Nb.sub.2 O.sub.5 16-20, WO.sub.3 0-3, with Nb.sub.2 O.sub.5 :TiO.sub.2 =0.6-0.71.
February 7, 1986
Date of Patent:
March 29, 1988
Danuta Grabowski, Ludwig Ross, Volkmar Geiler
Abstract: To tellurite optical glass comprising TeO.sub.2, high valence components are added and may be a combination of La.sub.2 O.sub.3, at least one of B.sub.2 O.sub.3 and GeO.sub.2, and at least one of Ta.sub.2 O.sub.5 and Nb.sub.2 O.sub.5. The high valence components may include Y.sub.2 O.sub.3, Gd.sub.2 O.sub.3, and Yb.sub.2 O.sub.3. Amounts of TeO.sub.2 and La.sub.2 O.sub.3 are restricted to ranges between 10% and 80% and between 5% and 35%, respectively. A sum of B.sub.2 O.sub.3 and GeO.sub.2 must fall within a range between 1% and 30%, with an amount of GeO.sub.2 restricted between 0% and 22%. A total of La.sub.2 O.sub.3, Y.sub.2 O.sub.3, Gd.sub.2 O.sub.3, and Yb.sub.2 O.sub.3 must be between 5% and 50%. A sum of Ta.sub.2 O.sub.5 and Nb.sub.2 O.sub.5 should range from 1% to 26%, with individual amounts of Ta.sub.2 O.sub.5 and Nb.sub.2 O.sub.5 kept between 0% and 20% and between 0% and 26%, respectively.