Pore-forming Patents (Class 501/80)
  • Patent number: 5772735
    Abstract: Supported inorganic membranes capable of molecular sieving, and methods for their production, are provided. The subject membranes exhibit high flux and high selectivity. The subject membranes are substantially defect free and less than about 100 nm thick. The pores of the subject membranes have an average critical pore radius of less than about 5 .ANG., and have a narrow pore size distribution. The subject membranes are prepared by coating a porous substrate with a polymeric sol, preferably under conditions of low relative pressure of the liquid constituents of the sol. The coated substrate is dried and calcined to produce the subject supported membrane. Also provided are methods of derivatizing the surface of supported inorganic membranes with metal alkoxides. The subject membranes find use in a variety of applications, such as the separation of constituents of gaseous streams, as catalysts and catalyst supports, and the like.
    Type: Grant
    Filed: July 18, 1997
    Date of Patent: June 30, 1998
    Assignees: University of New Mexico, Sandia Natl Laboratories
    Inventors: Rakesh Sehgal, Charles Jeffrey Brinker
  • Patent number: 5759932
    Abstract: An improved thermal barrier coating for metal substrates such as superalloys is provided. The coating is a slurry composition, comprising spheres of zirconia, at least some of which are hollow, contained within a porous oxide matrix, such as aluminosilicate. The slurry composition can be applied by slurry casting or similar techniques to the desired surface. Coating methods involve the application of successive layers of variations of the slurry composition, with various curing techniques used between layers and after the final coating is applied. Another embodiment of this invention embraces a composite coating, comprising (i) an oxide matrix phase; (ii) zirconia spheres embedded in the oxide matrix; and (iii) a porous phase.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: June 2, 1998
    Assignee: General Electric Company
    Inventors: D. Sangeeta, Lawrence Edward Szala, David Winfield Woodruff, Bangalore Aswatha Nagaraj, Daniel Scott McAtee, Clifford Lawrence Spiro
  • Patent number: 5753573
    Abstract: A slurry is molded from ceramic fibers and/or microparticles to form a soft felt mat which is impregnated with a sol prior to drying the mat. A catalyst for the sol is caused to diffuse into the mat by exposing the mat to the catalyst and subjecting the mat to a soak time during which the catalyst diffuses into the mat and causes the sol to gel. The sol-gel binder forms bonds so that the mat is dimensionally stabilized. The mat is dried to produce ceramic insulation.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: May 19, 1998
    Assignee: The Boeing Company
    Inventors: Michael E. Rorabaugh, Darryl F. Garrigus, Juris Verzemnieks
  • Patent number: 5750449
    Abstract: A ceramic porous body composed principally of silicon carbide or silicon nitride which has higher strength, higher heat resistance and higher thermal shock resistance and has a large number of fine pores, and a method of producing the same. The ceramic porous body, comprised principally of silicon carbide or silicon nitride, has a pore diameter of not more than 1 .mu.m, with a porosity of not less than 35%, and has a flexural strength of not less than 100 MPa. The ceramic porous body is produced by using a silicon oligomer which is capable of producing silicon carbide or silicon nitride when calcined, mixing the silicon oligomer with a silicon carbide powder or silicon nitride powder, and/or other ceramic powder which has a mean particle diameter of not more than 1.0 .mu.m, molding the mixture into shape, then sintering the molding in a suitable atmosphere at temperatures of not less than 1200.degree. C.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: May 12, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Koichi Niihara, Akira Yamakawa
  • Patent number: 5714000
    Abstract: Disclosed is a rigid fine-celled foam composition and a method of producing it. The foam composition is nontoxic, environmentally friendly, has improved absorption/adsorption and retention of liquids, is not as hard as prior art foams, does not include polymerization by-products detrimental to flower and plant life, and is a foamed mixture of a caustic silicate solution derived from the caustic digestion of rice hull ash having diffused activated carbon particles from thermal pyrolysis of rice hulls rather than from commercial sodium silicate solutions. Valuable by-products of commodity grade are obtained including activated carbon and sodium fluoride.
    Type: Grant
    Filed: July 10, 1996
    Date of Patent: February 3, 1998
    Assignee: Agritec, Inc.
    Inventors: Clyde W. Wellen, Douglas K. Stephens, Greg R. Wellen
  • Patent number: 5710203
    Abstract: Disclosed are compositions which can be used to form tamper-proof coatings on electronic devices. These compositions contain a silica precursor resin and a filler which reacts in an oxidizing atmosphere to liberate heat. Such compositions form coatings which, when oxidized by techniques such as plasma etching, wet etching, or cross-sectioning, liberate heat which causes destruction of the underlying substrate and, thus, inhibits further examination.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: January 20, 1998
    Assignee: Dow Corning Corporation
    Inventors: Robert Charles Camilletti, Loren Andrew Haluska, Keith Winton Michael
  • Patent number: 5707910
    Abstract: An object of the present invention is to provide an alumina-magnesia oxide which can be fine pulverulent bodies by pulverizing. In the alumina-magnesia oxide of the present invention includes: 70-73 WT % of alumina component, which is converted into alumina (Al.sub.2 O.sub.3); and 27-30 WT % of magnesia component, which is converted into magnesia (MgO). The alumina-magnesia oxide is formed into a pulverulent body, which is a hollow grain having loosed bulk density of 0.15 g/cm.sup.3 or less and average grain diameter of 10 .mu.m or more.
    Type: Grant
    Filed: March 28, 1996
    Date of Patent: January 13, 1998
    Assignee: Taimei Kagaku Kogyo Kabushiki Kaisha
    Inventors: Tokio Kamiyanagi, Takayuki Fujita, Noriho Harumiya
  • Patent number: 5705448
    Abstract: A gas generating substance is added to an aqueous dispersion containing refractory particles and a polymerizable monomer and the pressure and/or temperature are adjusted so that the substance generates the gas before the polymerization gets underway; to control the formation of pores.
    Type: Grant
    Filed: November 4, 1996
    Date of Patent: January 6, 1998
    Assignee: Dytech Corporation Limited
    Inventors: Rodney Martin Sambrook, Robert Terence Smith
  • Patent number: 5696217
    Abstract: The present invention provides for microporous ceramic materials having a surface area in excess of 100 m.sup.2 /gm and an open microporous cell structure wherein the micropores have a mean width of less than 20 Angstroms and wherein said microporous structure comprises a volume of greater than about 0.05 cm.sup.3 /gm of the ceramic. The pyrolysis product of ceramic precursor oligomers or polymers having a number average molecular weight in the range of from about 200 to about 100,000 g/mole in an ammonia atmosphere at temperatures of up to less than about 1200.degree. C. gives rise to the microporous ceramics of the invention. Also provided is a process for the preparation of the microporous ceramics of the invention involving pyrolysis of the ceramic precursor under controlled conditions of heating and with intermediate hold times, up to temperatures of less than 1200.degree. C., preferably less than 1000.degree. C., to form a microporous ceramic product.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: December 9, 1997
    Assignee: Exxon Research & Engineering Company
    Inventors: John Pickett Dismukes, John Stewart Bradley, Jack Wayne Johnson, Edward William Corcoran, Jr.
  • Patent number: 5696042
    Abstract: A ceramic porous body for a filter or a catalyst carrier, having a structure in which voids each having the same volume as that of a sphere of 10 .mu.m to 500 .mu.m in diameter are formed and the voids are communicated with each other through smaller fine pores, the ceramic porous body having a volume fraction of the voids and the fine pores of from 15% to 60% and being formed of components 70% or higher by volume of which is silicon nitride.
    Type: Grant
    Filed: September 21, 1995
    Date of Patent: December 9, 1997
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takahiro Matsuura, Chihiro Kawai, Akira Yamakawa
  • Patent number: 5688728
    Abstract: A porous ceramic material for a slidable member on unit such as a valve unit of a combination faucet. The porous ceramic material comprises a ceramic sintered body which is formed with pores dispersedly located therein. The pores are defined respectively by surface layers forming part of the ceramic sintered body. Each surface layer contains silicon in a content higher than that in other part of the ceramic sintered body. The porous ceramic material is prepared, for example, first by mixing ceramic powder and hollow particles each of which contains silicon so as to obtain a mixture; then by forming the mixture into a predetermined shape to obtain a formed body; and finally by sintering the formed body at a temperature higher than a melting point of each hollow particle to thus obtain the sintered body formed with pores and containing silicon.
    Type: Grant
    Filed: November 14, 1995
    Date of Patent: November 18, 1997
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Tomonori Niwa, Yusuke Makino
  • Patent number: 5688730
    Abstract: Gamma-aluminum oxynitride ground powders, white in color and well suited for conversion into optically transparent ceramic shaped articles, 100% of the particles of which being less than 10 .mu.m in size and exhibiting a transmittance of at least 8%, are prepared by grinding particulate gamma-aluminum oxynitride agglomerates having a porosity of greater than 75%, such agglomerates themselves being produced by interreacting dry powdery admixture of aluminum nitride, alpha-alumina, and an alumina of high specific surface area or precursor thereof.
    Type: Grant
    Filed: July 19, 1996
    Date of Patent: November 18, 1997
    Assignee: Elf Atochem S.A.
    Inventors: Roland Bachelard, Jean-Pierre Disson, Bruno Morlhon
  • Patent number: 5676745
    Abstract: Composites in the form of a three-dimensional framework or skeleton of ceic particles are formed by a low cost, low temperature sintering process which decomposes a pre-ceramic inorganic or organic precursor. Upon heating, preferably in air, the precursor decomposes to form a ceramic phase in the form of necks between the individual ceramic particles. The properties of the resulting porous ceramic bodies can be modified, such as toughened by impregnation with monomers, oligomers or polymers which are polymerized or cured in situ. Such composites find use as cosmetic products or protheses for humans and animals, such as dental restoratives and bone implants. Methods of fabrication are disclosed which include the use of a pre-ceramic polymer as a binder for the ceramic particles which forms the necks of material between the individual ceramic particles upon firing.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 14, 1997
    Assignee: The United States of America, as represented by the Secretary of Commerce
    Inventors: John Robert Kelly, Joseph M. Antonucci
  • Patent number: 5674792
    Abstract: A shaped body of amorphous silicon dioxide, which has a chemical purity of at least 99.9% and a cristobalite content of at most 1% and which is impermeable to gas, is known. To provide shaped bodies of amorphous silicon dioxide which have a high precision, which can be small or large in size and of simple to complicated shape, which have a chemical purity of at least 99.9%, are impermeable to gas above wall thicknesses of 1 mm, which have a high cold flexural strength, low thermal conductivity and low radiation of heat, which are thermal shock resistant and can be exposed repeatedly or also long-term to temperatures in the range from 1000.degree. to 1300.degree. C. and which can be welded in a sharply delineated manner without spreading joins and which have a low spectral transmission from the ultraviolet to the middle infrared spectral region, the shaped body is opaque, contains pores, at a wall thickness of 1 mm has a direct spectral transmission which is virtually constant in the wavelength range from .
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: October 7, 1997
    Assignee: Heraeus Quarzglas GmbH
    Inventors: Stephan Moritz, Wolfgang Englisch
  • Patent number: 5656250
    Abstract: A three-dimensional network structure comprising three-dimensionally interconnected spherical silica particles, having specific physical characteristics including diameter, pores on the surfaces of the particles, cross-sectional areas of the bonds interconnecting the spherical silica particles, elasticity modulus, voids content, and silica content, the surfaces of the spherical silica particles being wholly or partly covered with a water-soluble polymer, the network structure being able to remain substantially intact when heat-treated and being able to undergo machining. There is also provided a method of making a three-dimensional network structure comprising spherical silica particles, comprising hydrolyzing and polymerizing a low polymer of an alkoxysilane in a mixed solution containing the alkoxysilane low polymer and a water-soluble polymer in a mixed solvent composed of water and an alcohol in the presence of an acid catalyst.
    Type: Grant
    Filed: June 27, 1995
    Date of Patent: August 12, 1997
    Assignee: Jiro Hiraishi, Director-General, Agency of Industrial Science and Technology
    Inventors: Yuko Tanaka, Muneaki Yamaguchi, Hiromasa Ogawa, Katsutoshi Tanaka
  • Patent number: 5654246
    Abstract: A method of making self-supporting ceramic composite structures having filler embedded therein includes infiltrating a permeable mass of filler with polycrystalline material comprising an oxidation reaction product obtained by oxidation of a parent metal such as aluminum. The self-supporting ceramic composite structure optionally contains therein non-oxidized constituents of the parent metal. The structure is formed by placing a parent metal adjacent to a permeable filler and heating the assembly to melt the parent metal and provide a molten body of parent metal which is contacted with a suitable oxidant. Within a certain temperature region and optionally, aided by one or more dopants in or on the parent metal, molten parent metal will migrate through previously formed oxidation reaction product into contact with the oxidant, causing the oxidation reaction product to grow so as to embed the adjacent filler and provide the composite structure.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: August 5, 1997
    Assignee: Lanxide Technology Company, LP
    Inventors: Marc Stevens Newkirk, Harry Richard Zwicker, Andrew Willard Urquhart, John Peter Biel, Jack Andrew Kuszyk, Craig Barlow Shumaker, Harold Daniel Lesher, Terry Dennis Claar, Michael Kevork Aghajanian
  • Patent number: 5643512
    Abstract: The present invention is embodied in a method of producing a ceramic foam. The steps for producing the ceramic foam include first mixing a liquid pre-ceramic resin with a liquid phenolic resin, second allowing the resultant mixture to chemically foam, third curing the mixture for a time and at a temperature sufficiently to convert the mixture to a polymeric foam, and then heating the resultant polymeric foam for a time and at a temperature sufficiently to completely break-down polymers of the polymeric foam and convert the polymeric foam to a ceramic foam.
    Type: Grant
    Filed: August 16, 1995
    Date of Patent: July 1, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: David Eric Daws, Nicholas T. Castellucci, Harry Wellington Carpenter, Mary Wagner Colby
  • Patent number: 5643987
    Abstract: The present invention provides for microporous ceramic materials having a surface area in excess of 70 m.sup.2 /gm and an open microporous cell structure wherein the micropores have a mean width of less than 20 Angstroms and wherein said microporous structure comprises a volume of greater than about 0.03 cm.sup.3 /gm of the ceramic. The invention also provides for a preceramic composite intermediate composition comprising a mixture of a ceramic precursor and finely divided silicon carbide or silicon nitride, whose pyrolysis product in inert atmosphere or in an ammonia atmosphere at temperatures of up to less than about 1100.degree. C. gives rise to the microporous ceramics of the invention. Also provided is a process for the preparation of the microporous ceramics of the invention involving pyrolysis of the ceramic intermediate under controlled conditions of heating up to temperatures of less than 1100.degree. C. to form a microporous ceramic product.
    Type: Grant
    Filed: May 24, 1994
    Date of Patent: July 1, 1997
    Assignee: Exxon Research and Engineering Company
    Inventors: John Pickett Dismukes, Jack Wayne Johnson, Edward William Corcoran, Jr., Joseph Vallone, James J. Pizzulli, Jr., Michael P. Anderson
  • Patent number: 5632326
    Abstract: A mold for metal casting contains a bonded refractory composition comprising hollow alumina-containing microspheres in which the alumina content is at least 40% by weight. The mold may be an ingot mold and the bonded refractory composition may be in the form of a sleeve or boards located in the top of the mold or in the head box thereto. The mold may be a sand mold and the bonded refractory composition may be in the form of a sleeve or boards located in a feeder cavity or in the form of a board or pad located so as to constitute a metal casting surface where it is desired to promote directional solidification in cast metal. The bonded refractory composition may also be in the form of a breaker core. In a preferred composition the microspheres contain alumina and silica and the composition may also contain one or more other particulate refractory materials, a readily oxidizable metal, an oxidizing metal, an oxidizing agent for the metal and a fluoride salt.
    Type: Grant
    Filed: November 28, 1995
    Date of Patent: May 27, 1997
    Assignee: Foseco International Limited
    Inventor: Michael J. Gough
  • Patent number: 5618765
    Abstract: A ceramics porous body having a high porosity as well as high strength is especially suitable for use as a filter for removing foreign matter from a fluid or as a catalytic carrier. The porous body has a porosity of at least 30% and comprises columnar ceramic grains having an aspect ratio of at least 3. In particular, the porous body comprises Si.sub.3 N.sub.4 grains, of which at least 60% are hexagonal columnar beta-Si.sub.3 N.sub.4 grains. The porous body further comprises at least one compound of a rare earth element in an amount of at least 1 vol.% and not more than 20 vol.% of an oxide of the rare earth element, and optionally at least one compound of elements of the groups IIa and IIIb of the periodic table and transition metal elements in an amount of not more than 5 vol.% of an oxide of each element. A compact of mixed powder obtained by adding the compound powder of the rare earth element to silicon nitride powder is heat treated in a nitrogen atmosphere at a temperature of at least 1500.degree. C.
    Type: Grant
    Filed: January 6, 1995
    Date of Patent: April 8, 1997
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hisao Takeuchi, Seiji Nakahata, Takahiro Matsuura, Chihiro Kawai
  • Patent number: 5618762
    Abstract: An antibacterial ceramic contains an antibacterial material produced by loading an antibacterial metal such as silver on a calcium ceramic carrier and an inorganic material such as cordierite, and has a bulk density of 0.6-1.2 g/cm.sup.3. An antibacterial ceramic filter contains an antibacterial material produced by loading an antibacterial metal such as silver on a calcium ceramic carrier, an aggregate such as mullite, and a binder such as frit, and has a porosity of 20% or more. The light-weight antibacterial ceramic is suitably applicable to a roof garden or the like. The antibacterial ceramic filter can remove and extirpate various bacteria and suspensions.
    Type: Grant
    Filed: May 11, 1995
    Date of Patent: April 8, 1997
    Assignees: NGK Insulators, Ltd., NGK Adrec Co. Ltd., Sangi Co. Ltd.
    Inventors: Hiroshi Shirakawa, Osamu Yamakawa, Hiroaki Nihonmatsu, Kiminori Atsumi
  • Patent number: 5614255
    Abstract: Proposed is an efficient method for the preparation of vitreous hollow microspheres from particles of a vitreous volcanic deposit by a heat treatment to effect expansion of the particles by foaming. The inventive method comprises a step, prior to the heat treatment for expansion of the particles, in which the starting particles are dispersed in an aqueous medium containing aluminum sulfate and urea each in a specified concentration followed by a heating treatment of the dispersion so as to deposit a coating layer of aluminum hydroxide on the particle surface so that the efficiency of foaming can be greatly improved without the disadvantage of particle agglomeration.
    Type: Grant
    Filed: July 9, 1996
    Date of Patent: March 25, 1997
    Assignee: Japan as represented by Director General of Agency of Industrial Science and Technology
    Inventors: Kunio Kimura, Hiroyuki Nakamura, Yukiyoshi Tamoto, Junichi Kimoto, Hiromi Okada
  • Patent number: 5612266
    Abstract: Disclosed is a decorative, non-combustible, synthetic fire-log for use in a gas or oil burning fireplace or stove. This synthetic fire-log has a density ranging from 15 to 45 lb/pi.sup.3. It is made by pouring a mineral foam into a mold shaped as a natural wood-log and letting this foam harden in the mold to form the synthetic fire-log prior to unmolding the same and letting it dry. The foam that is used for such a molding comprises 1 part by weight of a solution of phosphoric acid in which polyvinyl alcohol is dissolved in such an amount as to make the solution viscous; from 0.03 to 6 parts by weight of wollastonite containing from 0.5 to 4% by weight of a carbonate salt; from 0.2 to 10 parts by weight of water optionally one or more pigments to give a natural wood-like aspect to the synthetic fire-log; and, optionally also, a small amount of reinforcing glass fibers. The synthetic fire-log that is so-obtained looks like a natural wood-log and has the same glowing aspect in use.
    Type: Grant
    Filed: March 21, 1996
    Date of Patent: March 18, 1997
    Assignee: Cerminco Inc.
    Inventors: Pierre Delvaux, Normand Lesmerises, Marcel Gouin
  • Patent number: 5610109
    Abstract: A method for producing high surface area, thermally stable, microporous porous ceramic materials involves replacing a portion of the silicon in a sol or gel comprising silica (silicon dioxide) with cations of another metal. The metal-substituted silica sols are dried and fired to yield porous ceramic materials. Similarly, metal-substituted gels are fired to yield porous ceramic materials. When compared with unsubstituted silica materials, the materials thus produced offer advantageous benefits including improved stability in a basic environment, enhanced thermal stability, and advantageous surface properties such as intrinsic negative charge.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: March 11, 1997
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Marc A. Anderson, Lixin Chu
  • Patent number: 5601674
    Abstract: A method for making an environmentally stable, fiber reinforced ceramic matrix composite member includes use as a bonding agent of a ceramic precursor which transforms upon heating to a ceramic phase. The ceramic phase bonds together discontinuous material comprising ceramic particles, and reinforcing fibers at a relatively low processing temperature.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: February 11, 1997
    Assignee: General Electric Company
    Inventors: Andrew Szweda, Michael L. Millard, Michael G. Harrison
  • Patent number: 5591379
    Abstract: This invention describes a composition of matter having moisture gettering properties and applicable as coating or adhesive in a hermetic microelectronic device. The composition is applied to the interior surface of the packaging at a thickness of 0.1-25 mil and comprises a desiccant finely dispersed in a binder which is a water vapor permeable solid material. This may be a polymer, porous ceramic or glass. The desiccant is a particulate solid with 0.2-100 micrometer average particle size. It ought to be able to absorb from a one atmosphere pressure gas containing one volume percent water vapor at least four parts by weight of water vapor per 100 parts by weight of desiccant at 25.degree. C., and for high reliability devices, it should also be able to absorb at least two parts by weight of water vapor per 100 parts by weight of desiccant at 100.degree. C. The desiccant to binder volume ratio ought to be between 0.002 and 2.
    Type: Grant
    Filed: August 2, 1993
    Date of Patent: January 7, 1997
    Assignee: Alpha Fry Limited
    Inventor: A. Andrew Shores
  • Patent number: 5580834
    Abstract: A self-sintered silicon carbide/carbon-graphite composite material having interconnected pores which may be impregnated, and a raw batch and process for producing the composite material, is provided. The composite material comprises a densified, self-sintered matrix of silicon carbide, carbon-graphite inclusions and small amounts of any residual sintering aids, such as boron and free carbon, and has interconnected pores which may be impregnated with resin, carbon, TEFLON, metal or other compounds or materials selected for their particular properties to achieve desired tribological characteristics for a specific application. The composite material is produced from a raw batch which includes silicon carbide, sintering aids, a temporary filler and coated graphite particles. The raw batch is then molded/shaped into a green body and heated to carbonize any carbonizable materials and to decompose and volatilize the organic filler to form a matrix of interconnected pores.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: December 3, 1996
    Assignee: The Morgan Crucible Company plc
    Inventor: Mark E. Pfaff
  • Patent number: 5573580
    Abstract: A founder's black for producing mould coatings is disclosed, whose main component consists of finely ground refractory to highly refractory inorganic materials. The black wash contains 1 to 40% by weight inorganic hollow spheres, in relation to the ready-to-use black wash. It may further contain 0.1 to 10% by weight of inorganic or organic fibers, in relation to the ready-to-use mould coating. The hollow spheres are preferably filled with an inert gas. They may consist of oxides such as aluminium oxide, quartz, magnesite, mullite, chromite, zircon oxide and/or titanium oxide, or borides, carbides and nitride such as silicium carbide, titanium carbide, or carbon, glass or metals, or mixtures thereof. The fibres have 1 to 30 .mu.m diameter, preferably 3 to 10 .mu.m and 10 to 5000 .mu.m length, preferably 100 to 500 .mu.m length.
    Type: Grant
    Filed: January 5, 1995
    Date of Patent: November 12, 1996
    Assignee: Huttenes-Albertus Chemische Werke GmbH
    Inventors: Dietmar Bartsch, Klaus Seeger, Hans-Dieter Kaiser
  • Patent number: 5573919
    Abstract: An assay for detecting an analyte which comprises applying a sample containing analyte to a surface of an absorbent material having at least one binder for the analyte supported on at least a portion of the surface. The absorbent material has a porosity which is capable of retaining non-charged particles having a size of at least 0.1 micron and no greater than 10 microns on the surface thereof. The sample flows past the binder and into the absorbent material. Porous plastics or ceramics are preferred absorbent materials.
    Type: Grant
    Filed: May 24, 1993
    Date of Patent: November 12, 1996
    Assignee: Carter-Wallace
    Inventors: Kevin Kearns, Richard McPartland
  • Patent number: 5571848
    Abstract: The invention provides a method for producing a microcellular foam of a curable material by replicating a dissolvable particle preform and leaching away the dissolvable particle preform to yield the microcellular foam. The foam can be a preceramic polymer microcellular foam which can be pyrolyzed to form a ceramic microcellular foam. A method for making a composite including steps of producing a ceramic microcellular foam which is subsequently infiltrated to form the composite is also provided as are microcellular foams, ceramic microcellular foams and composites prepared according to the method of the invention.
    Type: Grant
    Filed: January 20, 1995
    Date of Patent: November 5, 1996
    Assignee: Massachusetts Institute of Technology, a Ma corp.
    Inventors: Andreas Mortensen, Thomas J. Fitzgerald
  • Patent number: 5563106
    Abstract: A method of making a porous refractory article and a dispersion of particles in a liquid carrier, the method involving forming a dispersion of particles in a liquid carrier, introducing gas into the dispersion, removing the liquid carrier to provide a solid article having pores derived from the bubbles and wherein the dispersion has a critical viscosity below the level at which the introduction of gas cannot take place and above the level which entrapped gas bubbles will tend to escape and with the dispersion having the same critical viscosity.
    Type: Grant
    Filed: December 20, 1995
    Date of Patent: October 8, 1996
    Assignee: Dytech Corporation Limited
    Inventors: Jonathan G. P. Binner, Robert T. Smith, Jutta Reichert, Rodney M. Sambrook
  • Patent number: 5563212
    Abstract: The present invention provides for microporous ceramic materials having a surface area in excess of 50 m.sup.2 /gm and an open microporous cell structure wherein the micropores have a mean width of less than 20 Angstroms and wherein said microporous structure comprises a volume of greater than about 0.015 cm.sup.3 /gm of the ceramic. The invention also provides for a preceramic composite intermediate composition comprising a mixture of a ceramic precursor and finely divided particles comprising a non-silicon containing ceramic, carbon, or an inorganic compound having a decomposition temperature in excess of 400.degree. C., whose pyrolysis product in inert atmosphere or in an ammonia atmosphere at temperatures of up to less than about 1100.degree. C. gives rise to the microporous ceramics of the invention.
    Type: Grant
    Filed: May 24, 1994
    Date of Patent: October 8, 1996
    Assignee: Exxon Research and Engineering Company
    Inventors: John P. Dismukes, Jack W. Johnson, Edward W. Corcoran, Jr., Joseph Vallone
  • Patent number: 5560874
    Abstract: A rigid, monolithic, porous gas diffusion element which is formed of a body of solid particles and which is comprised of a partially coated, permeable ceramic substrate is disclosed. The substrate consists essentially of a porous first ceramic material, has an apparent porosity of from about 35 to about 50 percent, and has a minimum active pore size of from about 40 to about 120 microns; and it is partially coated with a coating which consists essentially of a second ceramic material has an apparent porosity of from about 35 to about 55 percent, and has a minimum active pore size of from about 10 to about 40 microns. The minimum active pore size of the substrate is from about 2 to about 5 times as great as the minimum active pore size of the coating.
    Type: Grant
    Filed: March 27, 1995
    Date of Patent: October 1, 1996
    Assignee: Refractron Technologies Corporation
    Inventors: Chad A. Sheckler, Harry C. Stanton
  • Patent number: 5558849
    Abstract: A process for making inorganic gels by reaction of tetraalkoxy orthosilicates, tetraalkoxy titanates and tetraalkoxy zirconates with strong carboxylic acids. Water need not be present initially as a reactant. Optically clear, very small pore size, narrow pore size distribution, and high specific area inorganic gels useful for abrasion-resistant coatings, optical applications, catalyst or enzyme support, gas separation, or chromatography packing are thus produced.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: September 24, 1996
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Kenneth G. Sharp
  • Patent number: 5556689
    Abstract: A microporous thermal insulation molding comprising compressed thermal insulation material comprising 30-100% by weight of finely divided metal oxide, 0-50% by weight of opacifier, 0-50% by weight of fiber material and 0-15% by weight of inorganic binder, wherein at least one surface of the molding has channel pores having a cross-sectional area of the pore of 0.01-8 mm.sup.2 and having an intrusion depth of 5-100%, based on the thickness of the molding, with 0.004-10 channel pores being present per 1 cm.sup.2 of the molding surface.
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: September 17, 1996
    Assignees: Wacker-Chemie GmbH, Elektro-Ger atebau GmbH
    Inventors: G unter Kratel, G unter Stohr, Martin Gross, Eugen Wilde
  • Patent number: 5552356
    Abstract: The present invention relates to boron subphosphide/aluminum oxide composite materials, to processes for the production of these materials and to the use thereof.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: September 3, 1996
    Assignee: Bayer AG
    Inventor: Nils Perchenek
  • Patent number: 5549850
    Abstract: Processes are provided for forming composites comprising a LaMnO.sub.3 perovskite coatings (or a related perovskite) on a mat of ceramic particles (e.g., fibers, microballoons, or mixtures thereof) or LaMnO.sub.3 -family sol-gel binders infused into the mat to form the connecting, rigidifying bridges.
    Type: Grant
    Filed: September 15, 1992
    Date of Patent: August 27, 1996
    Assignee: The Boeing Company
    Inventor: Darryl F. Garrigus
  • Patent number: 5530081
    Abstract: A plastic material composed of silicon carbide powder, polycarbosilane, organic solvent, and optionally boron compounds and/or other additives, preferably porosity agents; and the use of this plastic composition for producing shaped parts and semi-finished products by plastic shaping.
    Type: Grant
    Filed: April 1, 1994
    Date of Patent: June 25, 1996
    Assignee: Solvay Deutschland GmbH
    Inventor: Christoph Nover
  • Patent number: 5492870
    Abstract: Hollow microspheres of ceramic material are formed by a sol-gel technique involving forming and stabilizing an emulsion of an aqueous sol of the ceramic material in an organic phase, followed by dehydration of the stabilized emulsion droplets by extraction using a water-absorbing organic liquid, to form hollow gelled spheres, and finally recovery, drying and calcination of the spheres to the final product. The separation of the emulsion formation and dehydration steps into two distinct stages results in the ultimate formation of microspheres with improved uniformity and size distribution.
    Type: Grant
    Filed: April 13, 1994
    Date of Patent: February 20, 1996
    Assignee: The Board of Trustees of the University of Illinois
    Inventors: David L. Wilcox, Jay G. Liu, Jee-Loon Look
  • Patent number: 5482904
    Abstract: The present invention is intended to provide a heat-insulating refractory material, which does not contain environmentally and hygienically undesirable ceramic heat-insulating fibers, but only contains organic fibers to the extent necessary to improve adhesive rate upon spraying, and which can nevertheless achieve a specified heat-insulating effect. The heat-insulating refractory material includes a mixture containing 2-50 wt % of a foaming raw material foamed by heat at a temperature from 400.degree. to 1500.degree. C. and 50-98 wt % of a refractory powder, and a liquid binder which is added to the mixture in an amount of 20-250 wt % on the basis of the weight of the mixture.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: January 9, 1996
    Assignee: Krosaki Corporation
    Inventors: Hideaki Kawabe, Shozou Hagiwara, Koji Kuga, Setsunori Hamaguchi
  • Patent number: 5460854
    Abstract: A method of strengthening a fired porous ceramic core for use in investment casting includes the steps of providing a fired porous ceramic core, impregnating the core with an aqueous solution of a water-soluble gum, resin, or sugar, such as polyvinyl alcohol, and drying the impregnated core to remove the water.
    Type: Grant
    Filed: January 16, 1992
    Date of Patent: October 24, 1995
    Assignee: Certech Incorporated
    Inventor: Eugene Krug
  • Patent number: 5447653
    Abstract: Water purifying substances produced by mixing raw material soil containing allophane expressed by:nSiO.sub.2.Al.sub.2 O.sub.3.mH.sub.2 Owhere, n is a number within the range of 1.3 to 2, and m is a number within the range of 2.5 to 3 at the maximum larger than 0, with water, and sintering a mixture thus obtained at 200.degree. C. to 700.degree. C., consequently to form porous sintered particles having a function of absorbing and fixing phosphoric acid. By scattering the water purifying substances around a lake, marsh or other body of water, phosphoric acid in sludge accumulated in the lake and so on can be effectively captured. The purifying effect of the water purifying substance can be improved by adding polyaluminum chloride and/or ferrous sulfate to the raw material soil.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: September 5, 1995
    Assignee: Createrra Inc.
    Inventors: Tomotaka Yanagita, Yaozong Jiang
  • Patent number: 5443603
    Abstract: A method for manufacturing abrasive tumbling media comprising discrete abrasive particles having a preselected size and shape made by firing a formed mixture primarily comprising a particulate ceramic material, which method comprises adding at least 10% of hollow ceramic microspheres to said mixture prior to firing to obtain particles having a final fired bulk density below 65 lbs/ft..sup.3. The ceramic material preferably comprises at least 30 percent clay and the hollow microspheres have a shell consisting essentially of from 58 to 65 weight percent silica and from 28 to 33 percent by weight alumina, a shell thickness of about 10% of the diameter of the microsphere and an average particle size of from about 50 to 100 microns.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: August 22, 1995
    Assignee: Washington Mills Ceramics Corporation
    Inventor: Gregory S. Kirkendall
  • Patent number: 5441919
    Abstract: Ceramic foams in which the open cells are connected by a three-dimensional, substantially continuous ceramic matrix formed of interconnected hollow ligaments, are made from an open-cell, reticulated precursor metal, i.e. a metal foam. The precursor metal first is treated so as to allow a support coating to form thereon, and thereafter the coated precursor is heated above the melting point of the metal in the presence of an oxidant to form an oxidation reaction product.
    Type: Grant
    Filed: March 21, 1994
    Date of Patent: August 15, 1995
    Assignee: Lanxide Technology Company, LP
    Inventors: Eugene S. Park, Steven D. Poste
  • Patent number: 5439624
    Abstract: A method for producing high surface area, thermally stable, microporous porous ceramic materials involves replacing a portion of the silicon in a sol or gel comprising silica (silicon dioxide) with cations of another metal. The metal-substituted silica sols are dried and fired to yield porous ceramic materials. Similarly, metal-substituted gels are fired to yield porous ceramic materials. When compared with unsubstituted silica materials, the materials thus produced offer advantageous benefits including improved stability in a basic environment, enhanced thermal stability, and advantageous surface properties such as intrinsic negative charge.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: August 8, 1995
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Marc A. Anderson, Lixin Chu
  • Patent number: 5418195
    Abstract: There is disclosed a process for preparing porous ceramic granules, comprising(a) preparing a foam from an aqueous mixture of a particulate aluminosiliceous material and a fluxing material;(b) dividing the foam into discrete particles to form granules; and(c) calcining the granules at an elevated temperature such that sintering of the aluminosiliceous particles occurs.
    Type: Grant
    Filed: October 26, 1993
    Date of Patent: May 23, 1995
    Assignee: ECC International Limited
    Inventors: Jacek A. Kostuch, Jonathan A. Hearle
  • Patent number: 5399535
    Abstract: A reticulated ceramic product is provided having from about 5 to about 95 percent, preferably from about 10 to about 90, percent of the total porosity attributable to mesopores. Reticulated ceramic products provided include silicon oxide, aluminum oxide, zirconium oxide and ruthenium oxide. Reticulated ceramic products are prepared using a porous solid matrix as a template. The reticulated ceramic products are useful as chromatographic media, catalysts and adsorbents.
    Type: Grant
    Filed: August 17, 1993
    Date of Patent: March 21, 1995
    Assignee: Rohm and Haas Company
    Inventor: David W. Whitman
  • Patent number: 5397752
    Abstract: Disclosed is a porous sepiolite having an improved water-resistance and thermal shock resistance obtained by grinding, moisture-conditioning and molding sepiolite, and then calcining said molded sepiolite at a temperature in the range of about 650.degree. C. to about 800.degree. C. Also disclosed is a porous sepiolite having a large specific surface area, wherein the pores having a pore diameter of 50 angstroms or less have a specific surface area in the range of from 40 to 200 m.sup.2 /g and in which no less than 20% of the total surface of the sepiolite is occupied with the pores having a pore diameter of 50 angstroms or less and wherein the pore distribution curve of the sepiolite has a main peak at a pore diameter of no more than 50 angstroms. This sepiolite is obtained by grinding, moisture-conditioning and molding sepiolite, calcining the same at a temperature in the range of about 650.degree. to about 800.degree. C., and then subjecting said calcined sepiolite to an acid treatment.
    Type: Grant
    Filed: November 19, 1993
    Date of Patent: March 14, 1995
    Assignee: Nikki-Universal Co., Ltd.
    Inventors: Norio Inoue, Eiki Iida, Makoto Sakura, Hideyuki Yunoki, Koji Hara, Yoshiki Nakano, Takashi Aihara
  • Patent number: 5384290
    Abstract: Ceramic beads having a bimodal pore distribution are prepared by a process involving a) formation of a ceramic particle slurry, b) adding a foamable prepolymer to the slurry to form a mixture, c) dispersing the mixture as beads in a second liquid, d) polymerizing and foaming the prepolymer, e) recovering the beads and firing them to remove the polymer and bond the ceramic particles. The beads can optionally be joined by sintering. Beads with a monodal pore distribution can be made by using a non-foaming prepolymer.
    Type: Grant
    Filed: December 16, 1993
    Date of Patent: January 24, 1995
    Assignee: W. R. Grace & Co.-Conn.
    Inventor: Rasto Brezny
  • Patent number: 5384171
    Abstract: A structurally networked matrix ceramic composite material is disclosed as comprising either a continuous ceramic skeletal structure or a series of noncontinuous ceramic skeletal structure surrounded by a resilient polymeric, metallic etc. material to obtain a structural composite with a high compression and tensile strength of ceramics while permitting an accurate prediction of the strength of the resulting composite. Alternatively, the skeletal matrix structure could have no surrounding material or substrate. The matrix structure distributes to all connecting members the compressive and tensile forces resulting from loads on the overall composite.
    Type: Grant
    Filed: December 5, 1991
    Date of Patent: January 24, 1995
    Inventor: Bryan P. Prucher