Abstract: An improved method for the production of a monolithic multicomponent oxide glass is achieved by forming an oxide host gel by a sol-gel process, placing the host gel in an aqueous solution of a salt of at least one metal selected from the group consisting of Li, Na, K, Rb, Cs, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Pb, precipitating the metal salt in the gel and sintering the gel containing the precipitated salt. The method can incorporate large amounts of metals into the glass which are otherwise difficult or impossible to incorporate into precursor gels by conventional methods.

Abstract: A sol of flat silica particles (100-1000 nm in size) is produced by the following steps (a) to (d) from an acidic aqueous sol (S.sub.0) of negatively charged silica particles (7-30 nm in diameter) and an aqueous solution (B) of basic aluminum or zirconium salt.(a) mixing 100 parts by weight (as SiO.sub.2) of the sol (S.sub.0) with 0.2-10 parts by weight (as Al.sub.2 O.sub.3 or ZrO.sub.2) of the aqueous solution (B), and adjusting the resulting sol to pH 4-7, thereby yielding a sol (S.sub.1),(b) mixing 100 parts by weight (as SiO.sub.2) of the sol (S.sub.1) with 20-200 parts by weight (as SiO.sub.2) of the sol (S.sub.0), and adjusting the resulting sol to pH 4-7, thereby yielding a sol (S.sub.2),(c) mixing 100 parts by weight (as SiO.sub.2) of the sol (S.sub.2) with the aqueous solution (B) in an amount corresponding to 2-50% of the amount (as Al.sub.2 O.sub.3 or ZrO.sub.2 in parts by weight) added to 100 parts by weight (as SiO.sub.2) of the sol (S.sub.

Abstract: The present invention relates to ZrO.sub.2 - and SiO.sub.2 -based ceramic fibers in which the weight ratio between SiO.sub.2 and ZrO.sub.2 is comprised between 99 and 0.7. The tetragonal ZrO.sub.2 phase is stable at temperatures comprised between 0.degree. and 1500.degree. C. The process comprises the preparation of: a solution of Zr(OR.sup.1).sub.4, where R.sup.1 is an alkyl or aryl, Si(OR.sup.2).sub.4, where R.sup.2 is alkyl or aryl, an organic solvent and an acid. Vapor-phase water is bubbled in said solution, then the obtained solution is drawn and the fibers thus obtained are heated to obtain the crystallization of ZrO.sub.2 and SiO.sub.2.

Abstract: A method for production of high specific surface area silica gel by hydrolysis of silicon tetrahalide, wherein a solution of silicon tetrahalide in a non-reactive solvent such as alcohol is mixed with water to produce silica gel having a high surface area and narrow pore diameter distribution especially suited for use as normal phase packing material in high performance chromatography columns. The water contains fluoride ions if the halide is chloride. Reverse phase packing material can be prepared by reacting the normal phase silica gel with organochlorosilanes to prepare bonded reverse phase material for use in high performance liquid chromotagraphy systems.

Abstract: A body 20 includes a support structure 30 in which is formed monolithic aerogel 32 and has terminal insulating properties or other desirable properties. The body 20 can be enveloped in an impermeable membrane 34, 36 so as to allow a vacuum or another environment to be contained in the aerogel 32. The support structure 38 can include individual cells 22, each of which can support its own independent environment which is unaffected by the accidental or planned interruption in the environment of any adjacent cell 22.

Abstract: A method for producing a nonsintered cristobalite particles comprising heating amorphous silica particles at a temperature of 1400.degree. to 1700.degree. C. in the presence of cristobalite particles (hereinafter referred to as cristobalite particles for addition and mixing) of at least 5 parts by weight based on 100 parts by weight of said amorphous silica particles to convert said amorphous silica particles to cristobalite particles with their particle form kept unchanged. According to the present invention, dense cristobalite having a low alkali content can be obtained in the form of particles. Such cristobalite is used as a filler, a dispersing agent, etc., and also as a material for high-quality artificial quartz, ceramics, etc., and particularly as a material for transparent quartz glass because of its generating no bubbles at the time of melt-molding.

Abstract: Process for obtaining by sol-gel route refractory metal oxides based on silica in which a monolithic gel is prepared, in an aqueous medium, at a temperature of less than 60.degree. C., by leaving at rest an aqueous sol obtained by simple mixing in stoichiometric quantities of an aqueous sol of silicic acid and of one or more aqueous solutions of a water-soluble salt of one or more other constitutive metals of these oxides, then the monolithic gel obtained is calcined at a temperature of less than 1000.degree. C. after it has been dried at a temperature of less than 150.degree. C.

Abstract: A process for making non-porous, dense, silica partices having a diameter of about 3 to 1000 microns, a nitrogen B.E.T. surface area less than about 1 m.sup.2 /g, a total impurity content of less than about 50 ppm and a metal impurity content content of less than about 15 ppm from an aqueous dispersion of fumed silica. The particles are converted into porous particles and sintered in an atmosphere having a water partial pressure of from about 0.2 to about 0.8 atmosphere for temperatures below about 1200.degree. C.

Abstract: A method of manufacturing spherical silica particles comprising the steps of processing in an acid-containing solution and then washing with water the coagulant derived from an aqueous alkali metal silicate solution extruded through pores in a water-miscible organic medium or acid solution, wet-grinding the amorphous silica thus obtained in a liquid dispersion medium to obtain a fine particle silica suspension with a weight average particle size of 10 .mu.m or less, spray-drying this fine particle silica suspension with hot air and sintering the spherical granulated silica thus obtained. According to the present invention, the high-purity spherical silica particles can be obtained with high solidity and adjusted surface smoothness without any complicated operation or waste water treatment for use as a sealant filler for highly-integrated IC electronic parts.

Abstract: A method of producing a high purity silica powder which can be fused to form transparent, bubble-free particles. An ammonium fluosilicate solution is purified preliminarily by removing colloidal-sized silica onto which impurities in the solution have been adsorbed. The high purity powder is produced by ammoniation of an unsaturated aqueous solution of ammonium fluosilicate. Silica powder produced is filtered, washed, and dried before fusion. Additional pre-fusion treatments such as washing, hydrothermal leaching, calcination, and a combination thereof, may be utilized to ensure that the concentration of volatile material is low.

Abstract: A method for producing a uniform glass of a large size without forming bubbles and holes at the bottom thereof is provided. This method comprises concentrating a sol solution obtained by hydrolysis of a metal alkoxide such as alkoxide of silicon in the presence of an organic solvent and ammonia water until a volume of the sol solution reaches 1.00-1.95 times the volume of the charged metal alkoxide, then gelling the concentrated sol solution with addition of a mixed solution of an aqueous catalyst solution and an organic solvent, then drying the gel and heating the dry gel to sinter it.

Abstract: High purity, particulate silica gel is formed by the hydrolysis and condensation of a silicon alkoxide in a non-metal lined tumble dryer. The silica gel is then dried in the tumble dryer, is washed with an aqueous solution to remove trace contaminants, and is dried again to form the particulate product.

Abstract: A process for producing a rod-form silica from a silicic acid ester according to a sol-gel process, which silica has a rod-form having a high aspect ratio and is advantageously used as a filler for resin sealants for semiconductors, is provided, which process comprises adding 35 to 150 parts by weight of a sol of a silicic acid ester to 100 parts by weight of a hydrophobic medium to form an emulsion, subjecting the emulsion to a temperature rise at two stages, the first temperature rise being by 5.degree. to 30.degree. C. at a rate of 10.degree. to 200.degree. C./min. or less and the second temperature rise being by 3.degree. to 20.degree. C. at a rate of 0.5.degree. to 10.degree. C./min., to form a rod-form silica.

Abstract: A process for producing highly uniform microspheres of silica having an average diameter of 0.1-10 .mu.m from the hydrolysis of a silica precursor, such as tetraalkoxysilanes, which is characterized by employing precursor solutions and feed rates which initially yield a two-phase reaction mixture.

Abstract: There is provided by this invention a finely divided hydrated silica gel which has a specific surface area of 530 -720 m.sup.2 /g, preferably 550-650 m.sup.2 /g, a pore volume of 0.9-1.5 ml/g, preferably 1.0-1.4 ml/g, a mean pore diameter of 50-120 .ANG., preferably 60-100 .ANG., a water content of 7-25% by weight, preferably 8-13% by weight (wet weight basis), and moreover the pH of which as a 5% aqueous suspension is 6.0-8.0, thereby producing a silica gel suitable for stabilization treatment of beer, and for reduction of the colloidal components in beer.

Abstract: This invention concerns a process for producing high purity silica with less than 5 ppm of impurities from cheap alkali silicate aqueous solution (water glass) for industrial use, which commonly contains more than 2000 ppm of impurities, by directly adding water glass to a mineral acid solution, such as hydrochloric acid, nitric acid, and sulfuric acid so as to dissolve impurities in the mineral acid solution and form silica precipitate, and then rinsing the silica precipitate with a mineral acid solution, provided that the viscosity of the water glass is adjusted to 10-10000 poise in advance of adding to the mineral acid solution.

Abstract: Silica aerogels which exhibit very little shrinkage or partial growth during processing and drying are produced by foaming and reacting a mixture of an oxidated silicon compound, a salt forming compound and a gas in an aqueous medium. The foamed silica gel is then dried to remove water thereby producing silica aerogel.The silica aerogels may be used as a thermal and sound insulator, filler, catalyst, catalyst carrier, reinforcing agent, binder, absorbent, thickening agent and may have other uses.

Abstract: A method of making high purity, dense silica of large particles size is described. Tetraethylorthosilicate is mixed with ethanol and is added to a dilute acid solution having a pH of about 2.25. The resulting solution is digested for about 5 hours, then 2N ammonium hydroxide is added to form a gel at a pH of 8.5. The gel is screened through an 18-20 mesh screen, vacuum baked, calcined in an oxygen atmosphere and finally heated to about 1200.degree. C. in air to form a large particle size, high purity, dense silica.

Abstract: Disclosed is a filler for ink jet recording paper, said filler being composed of amorphous silica having a median diameter, measured by the coulter counter method, of 2 to 15 .mu.m, an oil absorption of at least 180 ml/100 g, a refractive index, measured by the solvent method, of at least 1.450, and a moisture absorption, measured when it is caused to absorb moisture for 200 hours at a relative humidity of 90% and a temperature of 25.degree. C., of at least 35%.

Abstract: This invention discloses novel, porous silica structures prepared from silica platelets. The structures are preferably prepared by spray-drying.

Abstract: Highly monodispersed nonporous spherical SiO.sub.2 particles are prepared having mean particle diameters between 0.05 and 10 .mu.m with a standard deviation of not more than 5% and a method for the preparation of such particles. The particles can be produced by a two step process wherein first a sol of primary particles is prepared by hydrolytic polycondensation of tetraalkoxysilanes in an aqueous/alcoholic ammoniacal medium. The SiO.sub.2 particles are then converted to the desired particle size by a continuous measured addition of tetraalkoxysilane or organotrialkoxysilane controlled by the extent of the reaction. The SiO.sub.2 particles produced by this process are particularly useful as sorption material in chromatography.

Abstract: Silica gels of a mean grain size of about 0.5 to 50 .mu.m are subjected to a heat or acid treatment that considerably reduces their surface area and the volume of pores smaller than 50 nm, while maintaining approximately the same grain size distribution and amorphous structure. These products are colorless and can be worked into a resinous molding material in relatively large quantities, especially as a filler for dental materials based on polymerizable monomers, in particular mono-, di- or polyfunctional esters of acrylic or methacrylic acid. In the completely hardened condition, these materials have good mechanical characteristics, less polymerization shrinkage, very low thermal expansion coefficients, excellent transparency and tooth similarity resulting from the favorable refractive index of the filler, as well as very good ability to be polished and abrasion resistance.

Abstract: ZSM-5 crystallites are produced with very low levels of blocking tetrapropyl ammonium ions (Q). The reaction mixture contains sources of silica, soda, alumina and trace amounts of Q ions as nucleation agents. Because the crystallites as synthesized from the aqueous medium exhibit only a very small fraction of blocking cations, there is always a diffusion path for the hydrated sodium ions to be exchanged without the need of prior removal of the blocking cations by calcination or otherwise. The small size crystallites can be exchanged, blended with other materials, and formed into catalyst particles. The silica to alumina ratio can be varied and when no aluminum is added, silicalite may be formed. The systhesis can be done in 24 hours or less.

Abstract: A process for adjusting at least one of the structural and surface characteristics of an oxide material, e.g. SiO.sub.2 or Al.sub.2 O.sub.3, by dehydration of a water-containing oxide gel under supercritical conditions by extracting the water with an extraction agent such as CO.sub.2 at a pressure above the critical pressure of the extraction agent.

Abstract: Three dimensional hydrophobic substantially inorganic porous structure comprises a myriad of cavities interconnected by holes in which the diameters of the cavities are in the range of from 0.5 to 100 .mu.m and the diameters of the holes are in the range of from 0.1 to 20 .mu.m the porosity of the structure having a narrow pore size distribution with the cavities having a pore volume of at least 2 cc/g for a predetermined 10 .mu.m range of sizes. The structure is preferably an inorganic oxide selected from the group comprising alumina, silica, titania, zirconia and mixtures thereof. The structure is preferably made from an oil-in-water emulsion with a silylating agent in the internal phase so as to render the structure hydrophobic.

Abstract: A method for forming articles which include silica-containing glass bodies, as well as the resulting articles, are disclosed. In accordance with the method, silica-containing gel particles are fused to form a glass body. In contrast to previous such methods, these particles are formed by mechanically, substantially uniformly subdividing either a substantially cohesive gel body, or an ungelled or partially gelled sol capable of yielding a substantially cohesive gel body, to form substantially uniformly sized, wet gel particles. Significantly, only substantially cohesive gel bodies which are also substantially elastic are useful in the invention, i.e., mechanical subdivision of non-elastic gel bodies results in these bodies undergoing plastic flow to yield non-particulate, pasty masses.

Abstract: A method for preparing silica gel particles, which comprises suspending a mixed solution of a silicic acid ester and water in an organic liquid immiscible with the mixed solution, followed by gelation wherein said organic liquid contains an ethyl cellulose having an ethoxy group content of at least 47% by weight and being soluble in the organic liquid.

Abstract: This invention provides a process for producing silica from silica sol which comprises preparing an acidic silica sol applied with a hydrogen peroxide treatment from an aqueous solution of alkali silicate, purifying the acidic silica sol by using a cationic exchange resin after pH adjustment and preparing silica from the silica sol obtained by neutralizing the thus purified acidic silica sol, that is, a production process for highly pure silica capable of removing, Ti as much as possible in the same manner as impurities such as Fe and Al.

Abstract: Aluminosilicate optical glass without boron oxide, comprising 60-95 mols % silica and at least 2 mols alumina, the remainder being made up of at least one oxide of a metal selected from silver and thallium. The glass may also contain caesium. Optical waveguide preforms and methods of making the same are also disclosed.

Abstract: A method of fabricating an ultraporous SiO.sub.2 containing gel monoliths having a predetermined mean pore size with narrow distribution of the size of the pores around the mean. A SiO.sub.2 containing sol is prepared while simultaneously controlling and preselecting the temperature, time and nature of aging solution, and drying the resultant gel to obtain an ultraporous SiO.sub.2 containing monolith having a predetermined mean pore size from about 10 .ANG. to about 400 .ANG. with narrow distribution of the size of pores around the mean and the resultant article.

Abstract: An ammonia aged silica which can be used for example, in an improved process for chillproofing a malt beverage. The silica is aged with ammonia for a prolonged period of time. Better stability with smaller amounts of silica are obtained.

Abstract: A process for producing fine spherical silica, comprising a step of hydrolyzing an alkoxysilane in a mixed solution comprising water and alcohol and containing an alkaline catalyst, wherein the amount of said alkaline catalyst is 0.5 to 10 in molar ratio to the alkoxysilane used, the concentration of water in said mixed solution of water and alcohol in 5 to 20 mol/lit., and the reaction temperature for said hydrolysis is 30.degree. C. or more.According to this process, there can be obtained highly monodisperse spherical silica containing only a very small amount of impurities and having a particle size of 100 nm or less.

Abstract: Incorporation of fluorine into a porous silica body, such as an unsintered body produced by a sol-gel method, by VAD or OVPO, reduces or eliminates bubble or pore formation upon re-heating of the glass formed by sintering of the porous material. Effective fluorine concentrations are between 0.01 and 5% by weight. The invention can be used advantageously in producing preforms and optical fiber.

Abstract: In the production of an article of extremely pure synthetic silicon dioxide, wherein silicon tetrachloride is mixed with water to effect hydrolysis, the resulting hydrolysis product is dried, and the resulting dried particulate product is further processed into the desired article, the improvement which comprises employing a ratio of silicon tetrachloride to water so that the hydrolysis product is in the form of a gel, distilling by-product hydrochloric acid out of the gel, preliminarily drying the gel at 100.degree. to 1000.degree. C. to produce an initial product, milling the initial product into a fine granulate at room temperature, separating from the milled granulate a fraction with a particle size of about 40 to 1000 .mu.m, and drying the screened-out granulate fraction while slowly heating to no more than 1400.degree. C. to form the resulting dried particulate product that is further processed into the desired article. As a result, high quality bubble free articles are produced.

Abstract: In one embodiment this invention provides novel microporous inorganic oxide glass monolith structures, which have improved mechanical strength and optical transparency. An invention glass monolith is produced by a novel sol-gel process, which utilizes trioxane as an essential additive during the gellation phase, to provide a glass monolith with micropores having uniformity of size and shape.

Abstract: High purity silica powder formed from a sol-gel process is made from a quantity of an industrial grade hydrolizable silicon organometallic substance mixed with a quantity of an industrial grade organic solvent miscible in said organometallic substance and with a quantity of an acidified water having a pH less than 2 to form a solution. The solution is heated, then dried to form a gel, milled, and calcined to form the pure silica powder and the pure powder used to form encapsulated micro-miniature circuits.

Abstract: A process for preparing spheroid particles of oxide compounds, having an average diameter of smaller than 3 microns. An emulsion is prepared of a hydrolyzable liquid oxide compound in a perfluoropolyether, the emulsion is reacted with water, water vapor or with a mixture, in any ratio, of water with a liquid miscible or immiscible with water so as to form an oxide hydrate which is recovered dried and calcined. Oxide compounds include oxides of Ti, Al, Zr, Si or B.

Abstract: Monolithic glass members are prepared by first hydrolyzing a solution of tetraethoxysilane in alcohol with an acid medium, and then gelating in a basic medium while using acid and base mediums to form compounds that volatilize during drying and sintering the gel. Substances, if any, which in the form of oxides can form a glass with SiO.sub.2, are added after hydrolyzing and prior to gelation.

Abstract: Combinations of silica gel and magnesium silicate have been found to be effective agents to prevent the formation of haze in beer. Said haze, often called chill haze, is prevented by contacting the ruh beer with the combination to remove some or all of the components that react to form the haze. The spent combination is removed from the beer in the usual manner.

Abstract: This invention relates to glass-ceramic packages for integrated circuits containing multi-layer, interconnected thick film wiring patterns obtained by co-sintering a glass-ceramic composite and copper, silver, palladium or gold based conductors at temperatures not exceeding about 1000.degree. C. The dielectric systems disclosed herein contains composites of borosilicate glasses and crystalline fillers which are fabricated by either mixing glass frit and the filler or by a sol-gel coating process.

Abstract: Ultra-low thermal expansion TiO.sub.2 --SiO.sub.2 glasses are prepared using a sol-gel process wherein a stable alkali silicate solution comprising colloidal TiO.sub.2 and having a pH above 9 is gelled to form a semisolid silicate gel, the gel comprising homogeneously dispersed colloidal TiO.sub.2 but being essentially free of agglomerated TiO.sub.2 particles, washing the gel with aqueous media to remove alkali therefrom, and finally drying and consolidating the gel to a clear, void-free TiO.sub.2 --SiO.sub.2 glass which is substantially free of compositional inhomogeneities and has a thermal expansion coefficient below that of pure fused silica.

Abstract: This invention relates to novel silica spheroids and to their production by a phase separation technique in which an aqueous alkaline stabilized silica sol and an aqueous solution of a non-adsorbing polymer are mixed and acidified to produce the new silica spheroids.

Abstract: A silicate optical glass article is made by forming a gel from a hydrolyzed silicon alkoxide. The resulting gel is molded, cured, dried, solvents removed, heated to form a dense glass having near net shape dimensions thereby reducing expensive polishing steps to obtain the desired final dimensions and surface quality.

Abstract: Highly monodispersed nonporous spherical SiO.sub.2 particles are prepared having mean particle diameters between 0.05 and 10 .mu.m with a standard deviation of not more than 5% and a method for the preparation of such particles. The particles can be produced by a two step process wherein first a sol of primary particles is prepared by hydrolytic polycondensation of tetraalkoxysilanes in an aqueous/alcoholic ammoniacal medium. The SiO.sub.2 particles are then converted to the desired particle size by a continuous measured addition of tetraalkoxysilane or organotrialkoxysilane controlled by the extent of the reaction. The SiO.sub.2 particles produced by this process are particularly useful as sorption material in chromatography.

Abstract: Special absorbers or getters are incorporated in hermetically sealed electronic circuits with organic components, for example, with parylene passivations, silver conductive adhesives, and sealing materials. The getter material, preferably BaAl.sub.4, is dispersed as an extremely fine-grained powder in a gas permeable, inert silicone rubber having a composition which varies according to the application. In short- or long-term thermal loading, for example in power hybrid systems, the proposed getters make it possible to intercept any corrosive fission products such as CO, CO.sub.2, NO/NO.sub.2, and water of reaction to avoid premature aging.

Abstract: In one embodiment this invention provides a novel sol-gel process for the production of microporous inorganic oxide glass monolith structures which have improved mechanical strength and optical transparency. An essential feature of the process is the use of trioxane during the gellation phase, to provide a glass monolith with micropores which have uniformity of size and shape.

Abstract: A finely divided metal oxide powdery composition, preferably with a narrow particle size distribution, is produced from a particulate, sol-gel derived composition containing agglomerates by heating the particulate composition in the presence of an effective amount of a composition which decomposes upon heating and forms a gas to break at least a portion of the agglomerates so as to yield the desired finely divided ceramic particle composition. Examples of suitable gas-forming agents for use in the present invention include the ammonium salts or amides of organic and inorganic acids, volatile acids, and gases dissolved in a suitable solvent, such as water, alcohol or ammonia.

Abstract: A process for the preparation of at least one porous oxide or hydroxide body comprises:(i) adding at least one body comprising a sol of the oxide or hydroxide to a fluid freezing medium; and(ii) raising the temperature of the solid, quenched sol so that solvent nucleation occurs, resulting in the formation of crystals of the dispersion medium, and the dispersion medium melts thereby leaving one or more porous oxide or hydroxide bodies.

Abstract: A method of preparing spherical microparticles of silica comprising adding an acid solution to a silicate solution before or after addition of an alkali metal alginate, ammonium alginate, starch, gelatin, pectin or mixtures thereof. The microparticles can be used to prepare macroporous materials having a controlled pore structure.

Abstract: Silica base material for dentifrice having excellent transparency, prolonged stability, and desired abrasiveness; has a specific surface area of 270-500 m.sup.2 /g as measured by BET method and 5-60 m.sup.2 /g by CTAB method, gives virtually amorphous X-ray diffraction pattern after firing at 1100.degree. C., and has a refractive index of 1.455-1.470. This base material can be prepared by reacting an alkali metal silicate solution with hydrochloric acid or sulfuric acid in the presence of an electrolyte, controlling the ratio of the rate of addition of chloride ion or sulfate ion to be at least 3:2 between the acidification stage in which the pH at the completion of the reaction is brought to 3.5 or less, and the silica crystallization stage in which the pH of the reaction system if brought to 10.0, and carrying out the acidification stage within 30 minutes.