Abstract: A free aggregate usable in forming wood concrete products is formed of a plurality of individual wood pinchips encased in kaolin to a degree sufficient to seal in water soluble "cement poisons" held in the pores of the chips, while maintaining the individual chips in a free aggregate form. The product is formed by a process which includes the step of encasing the individual particles with a mineralizing coating of the kaolin to a degree sufficient to seal in the water soluble cement poisons. As a preliminary step, the pores of the chips are sealed with an aluminum sulphate-water solution. Once cured, the chips are dimensionally stable, will not deteriorate and are not easily influenced by environmental conditions. Moreover, since the cement poisons are sealed within the chips, they cannot leach out to suppress hardening of a portland cement mix into which the chips may be introduced to form an aggregate in the formation of wood concrete products.
Type:
Grant
Filed:
September 13, 1989
Date of Patent:
May 28, 1991
Assignee:
Insul Holz-Beton Systems Incorp.
Inventors:
Hansruedi Walter, Leni M. Walter-Gurzeler
Abstract: The disclosure concerns the fabrication, by chemical process, of a ceramic material belonging to the system:Ba.sub.x Sr.sub.1-x (Ti.sub.u Zr.sub.v Hf.sub.w)O.sub.3The fabrication method comprises the following steps:preparation of an alcohol solution containing at least one titanium, zirconium or hafnium alcoholate,preparation of a determined quantity of hydrated barium hydroxide and/or hydrated strontium hydroxide in solid state;under violent shaking, dissolving of the hydroxide or hydroxides in the alcohol solution, and continuing of the reaction until a paste is obtained,drying of the paste obtained.
Type:
Grant
Filed:
August 30, 1989
Date of Patent:
May 21, 1991
Assignee:
Compagnie Europeenne de Composants Electroniques -LCC
Abstract: Asphalt additive compositions are described which comprise (A) a metallic organic strength improving compound and (B) an anti-strip compound. The metal of said metallic organic compound is selected from the group consisting of manganese, cobalt, copper, vanadium, molybdenum, cerium, iron, nickel, lead, zirconium, barium, calcium and zinc. The preferred metal is manganese. The anti-strip compound is designed to reduce water-induced damage to asphalt paving mixtures.
Abstract: A silicon nitride sintered body comprised of 1.5 to 3.0% by weight of Y.sub.2 O.sub.3, 0.1 to 1.0% by weight of Al.sub.2 O.sub.3 and 96 to 98.4% by weight of Si.sub.3 N.sub.4 wherein the Y.sub.2 O.sub.3 /Al.sub.2 O.sub.3 weight ratio is at least 2.5, and having a density of at least 3.0 g/cm.sup.3, exhibits a high oxidation resistance and a high strength at a high temperature. This silicon nitride sintered body is prepared by sintering a powdery mixture consisting essentially of 1.5 to 3.0% by weight of Y.sub.2 O.sub.3 powder, 0.1 to 1.0% by weight of Al.sub.2 O.sub.3 powder, and 96 to 98.4% by weight of Si.sub.3 N.sub.4 powder, the Y.sub.2 O.sub.3 /Al.sub.2 O.sub.3 weight ratio being at least 2.5, the oxygen content in the Si.sub.3 N.sub.4 powder being less than 2.0% by weight and the total metallic impurity content in the Si.sub.3 N.sub.4 being less than 200 ppm, at a temperature of 1,850.degree. to 2,000.degree. C. in a non-oxidizing atmosphere.
Abstract: An improved dry ground calcium carbonate filler is provided which is less sensitive to variations in relative humidity and does not promote premature viscosity increase in polyester molding compound. This filler is dry ground from a Caribbean micritic limestone to produce Class I and Class II fillers which are acceptable for use in polyester molding compound applications. A polyester molding compound containing this dry ground filler produces a composite having superior izod impact resistance and surface quality. In some situations filler loading levels may be increased 10-15% in the SMC/BMC without detrimental effects on the final composite.
Abstract: The invention relates to a process for preparing highly porous glass-ceramic molded parts having carbon atoms linked to silicon atoms, which comprises reacting a molded part, containing an organopolysiloxane which is solid at room temperature, and consists of units of the formula ##STR1## where R is a radical selected from the formulas ##STR2## and is linked via a single silicon-silicon bonded, in a non-oxidizing atmosphere or in vacuo at temperatures ranging from 700.degree. to 1300.degree. C.
Abstract: A glass composition consisting essentially of the following components present in the glass in the following mole percent ranges is shown:CHART I ______________________________________ CHEMICAL COMPOSITION RANGES mole percent ______________________________________ SiO.sub.2 58-68 Al.sub.2 O.sub.3 0-2 K.sub.2 O + Rb.sub.2 O + Cs.sub.2 O 0-3 PbO 10-15 Bi.sub.2 O.sub.3 0.3-2.1 MgO + CaO + BaO 10-20.4 B.sub.2 O.sub.3 0-4 As.sub.2 O.sub.3 + Sb.sub.2 O 0.1-1.1 ______________________________________A glass composition for manufacturing a high performance microchannel plate is also shown. A microchannel plate made from a glass composition consisting essentially of components in the glass range as defined above is also shown. A method for making a non-porous glass tubing comprising a hollowed out central area and having a transformation temperature in range of about 570.degree. C. to about 610.degree. C., a liquidus temperature below 1000.degree. C.
Abstract: Boron/nitrogen preceramic polymers are prepared by reacting (a) the product of mass thermolysis of a compound of Formula (1): ##STR1## in which A is a halogen atom and R is a hydrogen atom, a hydrocarbon radical, or an organosilyl or hydrogenoorganosilyl radical, with (b) an amino compound containing at least one --NH.sub.2 group; the resulting polymers are facilely pyrolyzed into boron nitride ceramic materials.
Type:
Grant
Filed:
April 3, 1989
Date of Patent:
May 14, 1991
Assignee:
Rhone-Poulenc Chimie
Inventors:
Pierre Ardaud, Jean-Jacques LeBrun, Gerard Mignani
Abstract: Polycrystalline ceramic bodies having uniform transparent optical characteristics are produced by providing a green compact, presintering that compact at a temperature in the range from about 1,350.degree. C. to about 1,650.degree. C. until the closed porosity stage is reached, hot isostatic pressing the presintered compact to collapse substantially all pores disposed at grain boundaries and resintering the hot isostatically pressed compact at a temperature in the range from 1,700.degree. C.-1,950.degree. C. to cause grain growth under conditions in which pores, within those grains which are consumed by the growth of other grains, collapse as the grain boundary of the growing grain passes through the location of the pore in the smaller grain being consumed.
Type:
Grant
Filed:
September 25, 1989
Date of Patent:
May 7, 1991
Assignee:
General Electric Company
Inventors:
Charles D. Greskovich, William P. Minnear, Milivoj K. Brun, Robert J. Riedner
Abstract: Polymeric ethylene-bridged chlorosilazanes, process for their preparation, ceramic materials which can be prepared from them containing silicon nitride, and their preparationThe invention relates to novel polymeric ethylene-bridged chlorosilazanes, their preparation, their further processing to a ceramic material containing silicon nitride, and this material itself. In order to prepare the polymeric chlorosilazanes, oligosilazanes of the formula (I) ##STR1## are reacted with at least one of the chlorosilanes ##STR2## in which R.sup.1 to R.sup.5 are C.sub.1 -C.sub.6 -alkyl or C.sub.2 -C.sub.6 -alkenyl groups, which may be identical or different.The polymeric chlorosilazanes according to the invention can be converted by reaction with ammonia into polysilazanes, which in their turn can be pyrolysed to ceramic materials containing silicon nitride.
Type:
Grant
Filed:
November 30, 1989
Date of Patent:
April 30, 1991
Inventors:
Tilo Vaahs, Marcellus Peuckert, Martin Bruck
Abstract: A material for treating heavy metals and metal ions. The material contains as its main components quicklime and cement, and also contains, with respect to the quicklime and the cement, 0.05 to 0.35% by weight of potassium chloride, 0.03 to 0.20% by weight of magnesium chloride, 0.03 to 0.20% by weight of sodium chloride, 0.03 to 0.25% by weight of calcium chloride, 0.00002 to 0.01% by weight of cobalt chloride, 0.00002 to 0.01% by weight of citric acid, and 0.001 to 0.02% by weight of sodium sulfate. Harmful heavy metals and metal ions contained in effluents, slurries and sludges can be securely and inexpensively confined in a state in which they are prevented from elution. A coating of a fatty acid may be formed on the surface of the quicklime.
Abstract: Low density silicon nitride ceramics having improved bending an specific strengths over known silicon nitride ceramics derived from silicon nitride powder and polysilazane precursors are prepared by (A) intimately mixing about 50-80% by weight of silicon nitride powder with about 15-50% by weight of perceramic polysilazane binder, (B) pulverizing the mixture to form particles having a particle size smaller than 105 micrometers, (C) separating from those particles any particles having a particle size larger than about 105 micrometers, (D) molding the resultant composition having a particle size not larger than about 105 micrometers, and (E) pyrolyzing the molded composition in an inert atmosphere to a temperature of about 1200.degree.-1450.degree. C.
Abstract: Desirable high infra red reflecting brown rutile pigment compositions are described which comprise from about 40 to about 50% by weight of titanium, from about 2.3 to about 4.5% by weight of manganese, from about 7.3 to about 11% by weight of tungsten, from 0.05 to about 5% of lithium and from about 0.1 to about 20% of cerium.The invention also relates to the method of preparing the brown rutile pigment compositions and to the use of such pigments as colorants for polyvinyl halide compositions, and in particular, polyvinyl chloride compositions.
Abstract: This invention relates to a ceramic article having a crystalline and continuous silicon nitride phase, iron and a rare earth oxide, the article having a surface area of at least 3.5 m.sup.2 /g, a thermal expansion coefficient smaller than 6.times.10.sup.-6 m/m/.degree.C. measured in the range 20.degree.-800.degree. C. and a porosity of at least 30%. The ceramic article may also contain a discrete porous oxide phase such as alumina, aluminates, silica, spinel, titania, zirconia, zeolites and mixtures thereof. Further, the porous oxide may also contain a metal oxide such as barium oxide, nickel oxide, iron oxide, rare earth oxides and mixtures thereof. The ceramic article may be used as a catalyst support. Methods of manufacturing the ceramic article are also disclosed.
Type:
Grant
Filed:
March 16, 1989
Date of Patent:
April 2, 1991
Assignee:
Allied-Signal Inc.
Inventors:
Gerald T. Stranford, Stephen T. Gonczy, Roy T. Mitsche
Abstract: A pyrolytic boron nitride with a highly oriented crystalline morphology of twinned boron nitride crystallites is produced by addition of a trace amount of zirconium into the boron nitride.
Abstract: A flexible magnetic blend composition is provided which is comprised of high energy ferrite magnetic particles in a flexible high temperature resistant and oil resistant polymer binder. The binder system is preferably a highly saturated nitrile rubber (HSN) or a polymer alloy of the same in which a HSN is the major polymer containing alloying polymers and/or additives which are compatible with processing, subsequent electron beam curing, and final product performance. The binder system is highly loaded usually from 55 to 65 volume percent with the high energy ferrite particles, i.e., barium and/or strontium ferrite particles, which can produce bonded magnets with a maximum energy product of at least 1.0 megagauss-oersteds, a remenance, Br, of at least 2000 gauss, a coercive force, H.sub.c, of at least 1800 oersteds, and an intrinsic coercivity, H.sub.ci, of at least 2000 oersteds.
Type:
Grant
Filed:
September 19, 1989
Date of Patent:
March 26, 1991
Assignee:
The B. F. Goodrich Company
Inventors:
Raymond C. Srail, Richard A. Glover, Tiong H. Kuan, Thomas R. Szczepanski
Abstract: Polysilazane addition polymers are prepared by (1) reacting ammonia with one or more halogenated organic silicon compounds to produce a cyclic silazane ammonolysis product and (2) reacting the ammonolysis product with from 0.1% to 30% by weight of an isocyanate, isothiocyanate, ketene, thioketene, carbodiimide, or carbon disulfide. Polysilazane addition polymers containing alkenyl or alkynyl groups can be cured by supplying energy to generate free radicals. The cured or uncured polymers can be pyrolyzed to produce silicon nitride-containing ceramic materials.
Abstract: A liquid coating composition comprises an organotin di- or tricarboxylate and an organic fluoroacid for forming a fluorine-doped tin-oxide coating on glass having good bulk resistivity and haze values. The method of coating a transparent substrate with the composition is also described. The preferred liquid coating composition comprises about 50 to 80 wt. % of dibutyltin diacetate, and about 20 to 50 wt. % of trifluoroacetic acid.
Abstract: This invention relates to materials produced by diluting in a solvent a preceramic mixture of a partially hydrolyzed silicate ester and a metal oxide precursor selected from the group consisting of an aluminum alkoxide, a titanium alkoxide, and a zirconium alkoxide. The preceramic mixture solvent solution is applied to a substrate and ceramified by heating. One or more ceramic coatings containing silicon carbon, silicon nitrogen, or silicon carbon nitrogen can be applied over the ceramified SiO.sub.2 /metal oxide coating. A CVD or PECVD top coating can be applied for further protection. The invention is particularly useful for coating electronic devices.
Abstract: In a method of effecting a glass-capsule HIP for producing a ceramic fired body having a porsity of less than 0.1%, a residual sintered carbon amount and/or an absorbed water amount in a ceramic formed body before inserting into the glass-capsule are set to predetermined values. Therefore, it is possible to obtain a ceramic sintered body having a high density and a high flexural strength.