Abstract: Water-repellent porous silica having uniform pores, which comprises silica skeleton wherein fluorine atoms are fixed through covalent bonds and which has an alkali metal content of not more than 10 ppb, is synthesized. By the water-repellent porous silica, a water-repellent porous silica film having uniform pores, which is applicable to a light functional material or an electron functional material, a process for preparing the same and uses thereof can be provided.

Abstract: A method for the production of silicon oxide particles includes the pyrolysis of a molecular stream with a silicon compound precursor, an oxygen source and a radiation absorbing gas. The pyrolysis is driven by a light beam such as an infrared laser beam. The method can be used in the production of nanoscale particles including highly uniform nanoscale particles.

Abstract: Particulate silica is prepared by feeding a gas mixture of an organohalosilane gas, a flammable gas capable of generating water vapor when burned, and a free oxygen-containing gas to a reaction chamber through a multiple-tube burner, whereby the organohalosilane is subjected to flame hydrolysis and oxidation reaction. The amount of the flammable gas fed is 0.5-9 mol per mol of the organohalosilane and such that the amount of water vapor resulting from combustion of the flammable gas is 1-6 times the stoichiometric amount, and the gas mixture is fed to the center tube of the burner such that it may have a linear velocity at the outlet of 50-120 m/sec, calculated in the standard state. The resulting silica has a surface area of 100-400 m2/g and a narrow particle size distribution of primary particles and ensures the transparency of silicone rubber filled therewith.

Abstract: Pyrogenically prepared silica doped with silver or silver oxide is prepared by feeding an aerosol into a flame such as is used for the preparation of pyrogenic silica, mixing the aerosol homogeneously with gas mixture before the reaction, then allowing the aerosol/gas mixture to react in a flame. The resulting pyrogenic silicas doped with silver or silver oxide are separated from the gas stream. The pyrogenic silica doped with silver or silver oxide by means of an aerosol can be used as a bactericidal filler.

Abstract: The invention provides apparatus and a method for exothermic treatment of siliceous feed material to provide an ash having a predominantly silica content, typically more than 97% by weight. The apparatus includes a cylindrical housing extending about a central axis and having first and second ends, and a central mixing zone adjacent the first end. A material intake carries the feed material into the housing and has an outlet in the mixing zone, and gas enters through a first gas inlet at the first end through guides to create an inner vortex extending axially about said axis. Gas also enters through guides in a second gas inlet at the second end to create an outer vortex which also extends axially but in the opposite direction from that of the inner vortex. However the inner and outer vortices rotate in the same direction. A gas outlet is positioned to receive spent gas from the housing and an ash outlet is positioned remotely from the mixing zone to receive the ash.

Abstract: The fine spherical silica having a particle size distribution in which maximum particle diameter is 24 &mgr;m, average particle diameter is 1.7 to 7 &mgr;m, and the proportion X1 of particles having a particle diameter of 3 &mgr;m or less in the total particles is 100/D50 to (18+100/D50) wt %, and the viscosity at 50° C. of a mixture obtained by blending a maximum of 80 wt % of the fine spherical silica with a liquid epoxy resin or silicone resin at room temperature is 20 Pa·s or less is provided. The spherical silica is useful as a filler for sealing resin composition which has excellent gap permeability and seals slight gaps, between a substrate and an IC chip and has high reliability.

Abstract: A method of making an aggregate having a carbon phase and a silicon-containing species phase is described and includes introducing a carbon black-yielding feedstock and a silicon-containing compound feedstock into different stages of a multi-stage reactor. The reactor operates at a sufficient temperature to decompose the silicon-containing compound and to form a carbon black phase from the carbon black-yielding feedstock. At least one of the feedstocks may include a diluent, such as an alcohol, water, and aqueous based solution, and mixtures thereof.

Abstract: An ultrafine particle silicon dioxide which comprises silicon dioxide powders in the range of ultrafine particles having a BET specific surface area of 350 m2/g or more and has a ratio of BET/CTAB specific surface areas of 0.6 to 1.1, a number average of primary particle diameters of 1 to 20 nm, void volume measured with a mercury porosimeter of 0.1 to 1.0 ml/g and linseed oil absorption of 350 to 600 ml/100 g. According to the present invention, the ultrafine particle silicon dioxide can provide various kinds of polymers with excellent mechanical strength and transparency as a filler.

Abstract: Hydrophobic silica fine powder is produced by pyrolyzing a silane compound to form a silica fine powder and hydrophobizing the silica fine powder with an organohalosilane as hydrophobizing agent in a fluidization vessel. A portion of the silica fine powder is bypassed to a waste gas line from the fluidization vessel and collected with a cyclone and bag filter, and the collected powder is fed to the fluidization vessel where it is hydrophobized. The amount of unreacted organohalosilane in the waste gases is reduced, alleviating the burden on waste gas treatment. The silica having the unreacted organohalosilane borne thereon is fed back to the fluidization vessel, increasing the reaction efficiency of organohalosilane.

Abstract: Hydrophobic silica fine powder is produced by pyrolyzing a silane compound to form a silica fine powder and hydrophobizing the silica fine powder with an organohalosilane in a fluidization vessel. Hydrophobized silica fine powder which flies out of the fluidization vessel is collected with a cyclone and bag filter which are held at a temperature of 100-500° C. An apparatus for carrying out the process is also provided. Under simple controlled conditions that involve holding the cyclone and bag filter for recovering fugitive silica from the fluidization vessel to temperatures of 100-500° C., the method and apparatus are able to recover essentially 100% of fugitive silica, thus increasing yield of the product and alleviating the burden on waste gas treatment.

Abstract: A method for producing an ultra fine silica powder, which comprises subjecting a raw material mixture containing a silica powder, a reducing agent comprising a metal silicon powder and/or a carbon powder, and water, to heat treatment at a high temperature in a reducing atmosphere with an oxygen concentration of less than 1 wt % to generate a SiO-containing gas, immediately cooling said gas in an atmosphere containing oxygen, and collecting fine particles.

Abstract: The present invention is directed to a method for making silica. A liquid, preferably halide-free, silicon-containing compound capable of being converted by thermal oxidative decomposition to SiO2 is provided and introduced directly into the flame of a combustion burner, which converts the compound to silica, thereby forming finely divided amorphous soot. The soot is vaporized at the site where the liquid is converted into silica by pneumatically atomizing the liquid with a stream of oxygen gas, or a mixture of oxygen gas and nitrogen gas. The amorphous soot is deposited on a receptor surface where, either substantially simultaneously with or subsequently to its deposition, the soot is consolidated into a body of fused silica glass.

Abstract: Hydrophobic silica fine powder is prepared by pyrolyzing a silane compound to give silica fine powder, then treating the silica fine powder with a hydrophobizing agent in a fluidization vessel containing at most 3 vol % of oxygen. The process effectively confers the pyrogenic silica with hydrophobicity.

Abstract: The present invention related to methods of manufacturing oxide, nitride, carbide, and boride powders and other ceramic, organic, metallic, carbon and alloy powders and films and their mixtures having well-controlled size and crystallinity characteristics. This invention relates, more particularly, to a development in the synthesis of the ceramic, metallic, composite, carbon and alloy nanometer-sized particles with precisely controlled specific surface area, or primary particle size, crystallinity and composition. The product made using the process of the present invention and the use of that product are also claimed herein.

Abstract: A boron oxide-silicon dioxide mixed oxide which has a BET surface of less than 100 m2g, and optionally containing oxides of aluminium, titanium or zirconium, is prepared pyrogenically by flame hydrolysis. The mixed oxide is used in glass making.

Abstract: Compacts based on pyrogenically produced silicon dioxide and having the following physical and chemical characteristics: Outer diameter 0.8-20 mm BET surface area 30-400 m2/g Pore volume 0.5-1.3 ml/g Breaking strength 10-250N Composition >99.8 wt. % SiO2 Other constituents <0.2 wt. % Abrasion <5 wt. % Apparent weight 350-750 g/l are produced in that pyrogenically produced silicon dioxide is homogenized with methyl cellulose, microwax and polyethylene glycol with addition of water, dried at a temperature of 80-150° C. and comminuted to a powder, optionally the powder is compressed into compacts, and heat-treated at a temperature of 400 to 1200° C. for a time of 0.5 to 8 hours. These compacts can be used as catalysts or catalyst carriers in vinyl acetate monomer production and ethylene hydration.

Abstract: Spent potliner from an aluminum reduction cell is subject to an acid digest and the digest may be adjusted to produce a first gas component comprised of at least one material selected from the group consisting of silicon tetrafluoride, hydrogen fluoride, hydrogen cyanide gas and water vapor, and a slurry component comprised of at least one material selected from the group consisting of carbon, silica, alumina, and sodium, iron, calcium and magnesium compounds. The first gas component is removed from the digester and heated to a temperature sufficiently high to convert said silicon tetrafluoride to fumed silica and hydrogen fluoride. Thereafter, the fumed silica is separated from the hydrogen fluoride to recover fumed silica from spent potliner material.

Abstract: An article of relatively pure silica, and a furnace and method of producing the article. The article is produced by collecting molten silica particles (24) in a refractory furnace in which at least a portion of the refractory has been exposed to a halogen-containing gas to react with contaminating metal ions in the refractory.

Abstract: The present invention provides a method of treating silica wherein silica is reacted with a di- or tri-functional organosilane in an aqueous acid medium to provide a crude organosilane-capped silica product containing organosilicon impurities. The organosilicon impurities are extracted from the crude product with an organic liquid to provide a purified product consisting essentially of organosilane-capped silica. The purified product is dried to provide a dry organosilane-capped silica. The aqueous acid medium can include a displacing reagent which displaces at least one reactive functional group of the di- or tri-functional organosilane. The present invention further provides-continuous methods of treating silica with di- and tri-functional organosilanes, wherein the organic liquid and/or the organosilicon impurities are recycled and reused.

Abstract: A process of treating spent potliner material from aluminum reduction cells and recovering useful products. In the process of the present invention, spent potliner material is introduced into an acid digester containing, for example, sulfuric acid. As a result of this step, a gas component is produced which includes hydrogen fluoride, silicon tetrafluoride and hydrogen cyanide. Also, a slurry component is produced which includes carbon, a refractory material including silica, alumina, sodium compounds such as sodium sulfate, aluminum compounds such as aluminum sulfate, iron compounds such as iron sulfate, magnesium and calcium compounds such as magnesium and calcium sulfate. The slurry component remains in the digester after the gas component is removed. The gas component is recovered and heated an effective amount to convert or decompose the silicon tetrafluoride to fumed silica, hydrogen cyanide to a remaining gas component including CO.sub.2, H.sub.2 O, and nitrogen oxides, as well as HF gas.

Abstract: Disclosed is a method for treating a waste gas and an apparatus thereof capable of reducing the space for establishing the apparatus for treating the waste gas and collecting minute particles formed by oxidizing and cooling the toxic waste gas flown into the apparatus for treating the waste gas through a collecting process without filtering the particles. When treating the waste gas generated in the semiconductor manufacturing process, it is not required to treat a byproduct as in the wet-type treating method and the polymers are collected effectively by means of cyclones separators having different diameters. As a result, as the filtering apparatus is not required excluding the cyclone separators, the cost for establishing the facilities can be reduced.

Abstract: Preparation of inorganic aerogels based on oxides of the metals magnesium, aluminum, silicon, tin, lanthanum, titanium, zirconium, chromium and/or thorium by producing a hydrogel in a sol/gel process, replacing the water in the hydrogel by an organic solvent, and drying the solvent-moist gel, takes place by conducting the drying step by exposing the solvent-moist gel to an ambient temperature which is above the boiling temperature of the solvent and at a pressure which is below the supercritical pressure of the solvent in such a way that the solvent within the gel is heated up very rapidly and evaporates.

Abstract: A hydrothermal process for preparing a modified amorphous silica has been prepared. The process involves mixing a slurry of a silica with a mineralizer such as sodium hydroxide or sodium carbonate at a temperature of about 85.degree. C. to about 300.degree. C. for a time of about 4 hours to about 10 days. The silica thus produced has a unimodal pore distribution with pores in the range of about 300 .ANG. to about 25,000 .ANG..

Abstract: A method for the preparation of hydrophobic fumed silicas which are useful, for example, as reinforcing fillers in rubber compositions. The method comprises two steps, where in the first step an aqueous suspension of fumed silica is contacted with an organosilicon compound in the presence of a catalytic amount of an acid to effect hydrophobing of the fumed silica. In the preferred method the first step is conducted in the presence of a water miscible organic solvent which facilitates hydrophobing of the fumed silica with the organosilicon compound and the fumed silica has a BET surface area greater than 50 m.sup.2 /g. In the second step the aqueous suspension of the fumed silica is contacted with a water-immiscible organic solvent at a solvent to silica weight ratio greater than 0.1:1 to effect separation of the hydrophobic fumed silica from the aqueous phase. In a preferred process the hydrophobic fumed silica has a surface area within a range of about 100 m.sup.2 /g to 750 m.sup.2 /g.

Abstract: A closed loop process for producing electronic grade polycrystalline silicon from silane and fume silica from silicon tetrachloride comprises the steps of:(a) subjecting impure silicon to hydrochlorination with hydrogen chloride to produce trichlorosilane and silicon tetrachloride together with minor amounts of dichlorosilane and monochlorosilane;(b) converting the trichlorosilane to silicon tetrachloride and silane;(c) converting the silane to polycrystalline silicon and hydrogen;(d) reacting the silicon tetrachloride from steps (a) and (b) with hydrogen and oxygen to produce fume silica and hydrogen chloride, and(e) recycling the hydrogen chloride from step (d) for use in step (a).

Abstract: A method of making an aggregate comprising at least a carbon phase and a silicon-containing species phase is disclosed. The method involves introducing a first feedstock into a first stage of a multi-stage reactor, and introducing a second feedstock into the reactor at a location downstream of the first stage. The first and second feedstock comprise a carbon black-yielding feedstock, and at least one feedstock also comprises a silicon-containing compound. The reactor is operated at a sufficient temperature to decompose the silicon-containing compound and to pyrolize the carbon black-yielding feedstock. An additional method is disclosed which involves making an aggregate comprising a carbon phase and a silicon-containing species phase using multi-stage reactor having at least three stages for introducing a feedstock, wherein at least one of the feedstocks comprises a carbon black-yielding feedstock and wherein at least one of the feedstock comprises a silicon-containing compound.

Abstract: Dehydroxylated, silica-containing, glass surfaces are known to be at least partially terminated by strained siloxane rings. According to the invention, a surface of this kind is exposed to a selected silane compound or mixture of silane compounds under reaction-promoting conditions. The ensuing reaction results in opening of the strained siloxane rings, and termination of surface atoms by chemical species, such as organic or organosilicon species, having desirable properties. These species can be chosen to provide qualities such as hydrophobicity, or improved coupling to a polymeric coating.

Abstract: The present invention is directed to a purified polyalkylsiloxane composition having a boiling point, under atmospheric conditions, of less than about 250.degree. C. and containing high boiling impurities, including siloxanes and silanol-terminated siloxanes, that have boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of less than 14 ppm. The present invention is further directed to a method of producing a purified polyalkylsiloxane composition, having a boiling point, under atmospheric conditions, of less than about 250.degree. C., by distilling a polyalkylsiloxane starting material containing high boiling impurities having boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of at least 14 ppm, under conditions effective to produce a purified polyalkylsiloxane composition having a boiling point under atmospheric conditions of less than about 250.degree. C.

Abstract: A gas phase process for the production of titanium dioxide powders having well-controlled crystalline and surface area characteristics is disclosed. In this process, which is preferably carried out in a laminar diffusion flame reactor, vapor phase TiCl.sub.4 and oxygen are mixed in a reaction area which is heated externally. The titanium dioxide powder formed is then collected. It is preferred that the heat source used be a hydrocarbon fueled (e.g., methane) flame. Optionally, a vapor phase dopant (such as SiCl.sub.4) may be added to the reaction mixture to desirably affect the physical properties of the titanium dioxide produced. In a particularly preferred embodiment, a corona electric field is positioned across the area where the combustion reaction takes place (i.e., the reaction area). High anatase, high surface area titanium dioxide powders made by this process are excellent photocatalysts. The products of this process and the use of those products as photocatalysts are also disclosed.

Abstract: Compacts produced from a pyrogenically produced oxide, magnesium stearate, methyl cellulose and urea are mixed together in the presence of water, compacted, dried, comminuted to a powder, and the powder is pressed with an isostatic press to compacts and the compacts tempered. The resulting compacts have an outside diameter of 16 to 100 mm.

Abstract: Crude fumed silica resulting from pyrogenic hydrolysis is purified by continuously feeding particulate silica and steam or a mixture of steam and air in a steam/air volume ratio of at least 1/2 through an upright column from its bottom toward its top for forming a fluidized bed within the column at a gas linear velocity of 1 to 10 cm/sec. and a temperature of 250.degree. to 400.degree. C., whereby steam deprives the particulate silica of the halide borne thereon, and removing fine particulate silica from which the halide has been eliminated from the top of the column. Using a simple apparatus, pure fine particulate silica is collected at a low cost of energy consumption.

Abstract: A process for preparing finely divided silica by reaction of gaseous or vaporizable silicon compounds in a mixture with gases forming water on combustion with air or oxygen in a flame includes producing discharges of gas in the combustion chamber by means of at least one gas gun. The apparatus for carrying out this process has applied to the outside of the combustion chamber wall at least one gas gun which produces a discharge of gas via an opening in the combustion chamber wall, preferably in conjunction with a nozzle on the inside of the combustion chamber wall.

Abstract: Granules based on silicon dioxide and having the properties:Average particle size: 10 to 120 .mu.mBET surface area: 40 to 400 m.sup.2 /gPore volume: 0.5 to 2.5 ml/gPore size distribution: less than 5% of the total pore volume exists of pores with a diameter<5 nm, remainder are meso- and macroporespH value: 3.6 to 8.5Tapped density: 220 to 700 g/lThey are prepared by dispersing silicon dioxide in water, spray drying, and optionally heating and/or silanizing. The granules can be used as catalyst supports.

Abstract: An improved moisture absorbing amorphous silicate material formed by the steps of: parboiling rice under 22 psi and at a temperature above 212 degrees F. to force bran into the rice grain and dissolve cellulose from the rice hulls creating voids in the rice hulls; drying the parboiled rice; milling the parboiled rice into grain, bran, and broken rice hulls; separating the broken rice hulls from the grain and bran; and burning the broken rice hulls at high temperatures to produce a skeletal residue of amorphous silicate material. Several uses of the amorphous silicate material are disclosed.

Abstract: A vacuum extraction system is connected to a reactor vessel in which a chemical vapor deposition (CVD) process is carried out by using a suitable starting gas. The system comprises a pump for extracting a vacuum from the vessel, and a trapping device provided in the vessel and the pump for treating a starting gas pulled from the vessel into the system during the CVD process. The treatment of the starting gas pulled from the vessel is performed by using a gaseous oxidizing agent for separating a deposition component from the starting gas pulled from the vessel as an oxide, whereby a build-up of the component of the gas can be prevented in the pump. The trapping device comprises a tank body for receiving the starting gas pulled therein, and a perforated tube for introducing the gaseous oxidizing agent into the tank body to separate the deposition component of the received starting gas therefrom as an oxide.

Abstract: The invention relates to a process for continuously hydrophobicizing pyrogenic, finely divided silica, in which the waste gases are fed back to a mixing chamber upstream of the SiO.sub.2 reaction flame.

Abstract: A thrust vectoring panel which is a hybrid ceramic/ceramic composite consisting of three layers of lightweight materials, the anisotropic properties of which are manipulated such that the properties of the materials, i.e., the coefficient of thermal expansion, the strain energy release rate, and the tensile and flexure modules, either match or gradually transition from material to material. The three layers include a face layer which is of a high temperature capable material that can withstand temperatures within a range of 2300.degree.-25000.degree. F. for an extended period of time and a temperature as high as 28000.degree. F. for a short period of time. The middle layer simply is an insulating layer for providing adequate thermal insulation for the activator mechanism for the thrust panel. The third layer is a skeletal structure or layer which is of a lightweight material having sufficient strength to support all the integral interfaces, such as the activator mounts and the like.

Abstract: A method is provided for making fumed silica aggregate having an average convex perimeter in the range of about 0.12 micron to about 0.6 micron based on the combustion of a mixture of a silicon compound, such as an organosilane, an oxygen containing gas, such as air and a fuel such as hydrogen. The fumed silica aggregate has been found to enhance properties in heat curable filled silicone compositions.

Abstract: The black powder to be treated is injected into the bottom portion of a heated dense fluidized bed, said bed having effective depth enabling the carbon the particles of silica to be oxidized into carbon dioxide as the particles go through the dense fluidized bed while being entrained by the fluidization air. The whitened powder is then recovered by filtering the gases leaving said dense fluidized bed. The invention is particularly applicable to the cosmetics industry for producing make-up that uses silica powder.

Abstract: Polysiloxanes containing both alkylhydrosiloxane units and alkylvinylsiloxane units which polysiloxanes are siloxy-endblocked that are useful as starting materials in the preparation of silicon oxycarbide ceramic compositions, a process for their preparation, a process for preparing silicon oxycarbide ceramic compositions therefrom, and novel silicon oxycarbide ceramic compositions are described.

Abstract: Ceramic oxide powders and a method for their preparation. Ceramic oxide powders are obtained using a flame process whereby two or more precursors of ceramic oxides are introduced into a counterflow diffusion flame burner wherein said precursors are converted into ceramic oxide powders. The morphology, particle size, and crystalline form of the ceramic oxide powders are determined by process conditions.

Abstract: A method is provided for producing a carbide compound, such as silicon carbide. A reactor is provided which has a chamber defined therein which is divided into a combustion zone and a reaction zone. A combustible mixture comprising carbon monoxide and an oxidant is injected into the combustion zone and accordingly combusted to form hot combustion products. At least one reactant is injected at the boundary between the zones so as to be carried into the reaction zone by the combustion products and react to produce a precursor product powder comprising an oxide, such as silicon dioxide, and carbon. This precursor product powder is heated in an inert atmosphere to yield the desired carbide compound.

Abstract: This invention relates to the production of high purity fused silica glass through oxidation and/or flame hydrolysis of a halide-free, organosilicon-R compound in vapor form having the following properties:(a) producing a gas stream of a halide-free silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO.sub.2 ;(b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO.sub.2 ;(c) depositing said amorphous particles onto a support; and(d) either essentially simultaneously with said deposition or subsequently thereto consolidating said deposit of amorphous particles into a virtually nonporous body; the improvement comprising utilizing a halide-free, organosilicon-R compound in vapor form having the following properties:(1) a Si--R bond dissociation energy that is no higher than the dissociation energy of the Si--O bond;(2) a boiling point no higher than 350.degree. C.

Abstract: The invention relates to a process for preparing spherical, monodispersed organopolysiloxanes, which comprises reacting an alkoxysilane of the general formula ##STR1## in which the R's are selected from the group consisting of methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl or tert-butyl radicals, with water at a molar ratio of water to alkoxysilane of 40 moles:1 mole to 80 moles:1 mole, and a process for preparing spherical, monodispersed silicon oxycarbides from these organopolysiloxanes.

Abstract: A method and apparatus for the combustion treatment of a toxic gas which forms microparticles by combustion are disclosed wherein the toxic gas is subjected to a combustion treatment in a specific combustion furnace where the combustion gas formed is brought into contact with an aqueous film flowing downwards on the inner wall of the furnace from the upper end portion thereof to the lower end portion thereof or with a cooled surface, and then optionally with aqueous droplets dispersed in the interior space of the furnace. The water captures the microparticles formed by combustion of the toxic gas and is discharged out of the furnace as a mixed flow with the combustion gas thus treated, and optionally the mixed flow is successively treated in a gas-liquid separator.

Abstract: A process for preparing a particulate metal oxide of small particle size wherein a combustible organometallic compound alone or in admixture with a combustible organic liquid carrier is introduced into a combustion zone and combusted in a combustion supporting gas to produce particles of metal oxide, the combustion being carried out under reaction conditions so as to effect calcination of the metal oxide particles prior to condensation of the particles in the bulk phase.

Abstract: The manufacture of semiconductor devices and, specifically, deposition of SiO.sub.2 films on semiconductor devices by oxidative decomposition of oligo siloxanes at low temperature is disclosed.

Abstract: The present invention concerns synthetic mica powder containing from 75 to 99% of the stoichiometrical composition of fluorine and/or having a shape in which the end face of particle is laminated, process for producing such synthetic mica powder, as well as cosmetics having synthetic mica powder blended therewith, in which the synthetic mica powder shows no leaching of fluorine ions and/or improved hold of oils due to lamination at the surface of powder. Accordingly, in this invention, cosmetics excellent in extensibility, gloss, adherence and modability, having appearance of high chroma and of high stability and safety can be obtained.

Abstract: Coatings, which act as barrier layers to inhibit migration of alkali metal ions from a glass surface and/or act as color suppressing underlayers for overlying infra-red reflecting or electrically conducting layers, are deposited by pyrolysis of a gaseous mixture of a silane, an unsaturated hydrocarbon and an oxygen-containing gas other than carbon dioxide which does not react with the silane at room temperature on a hot glass surface at a temperature of 600.degree. C. to 750.degree. C.

Abstract: A process for preparing compound metal oxides, superconductive compound oxides, is disclosed. The process comprises preparing an aqueous solution containing a predetermined content ratio of chloride, nitrate or acetate of a rare earth metal, an alkaline earth metal and copper, said content ration corresponding to the composition of the object compound metal oxide, adjusting the pH of the solution to 1.5-2.0, adding oxalic acid in an amount such that the concentration of the residual oxalic acid becomes 0.05 M/l-0.1 M/l, collecting the thus formed precipitate and firing it.