Abstract: There is proposed a silica gel for preventing the generation of haze in beer, a method of manufacturing the silica gel and a method of stabilization treatment of beer. The silica gel is provided with a specific surface area of 700-1000 m2/g, a pore volume of 1.1-1.6 ml/g and a average pore diameter of 6-10 nm, and has a relatively high adsorbability per unit weight. In the method of manufacturing the silica gel, the washed, hydrothermally treated, acid treated, ground and dried silica hydrogel is calcined at 400-800° C. for 10 seconds to 10 hours. A haze causing component can be removed from beer by contacting the silica gel with the beer and subsequently separating the silica gel from the beer.

Abstract: A process for the preparation of precipitated silica is disclosed. The precipitated silica has a refractive index from about 1.440 to about 1.450, among other properties. The silica is prepared by a method including; a first step of using an initial feedstock of water, an electrolytic salt and a fraction of the total amount of silicate employed; a second step including preneutralizing the feedstock with the acidifying agent until about 50 to 85% of the amount of M2O present has been neutralized; a third step including introducing into the preneutralized feedstock the remaining fraction of alkali metal silicate in aqueous solution and the acidifying agent, under conditions such that the pH of the reaction medium remains substantially constant and from about 8.6 to about 9.

Abstract: Porous inorganic silica foam compositions are derived from water soluble silicate precursors and swollen non-ionic polymer templates are described. The compositions are useful as catalyst supports and as catalysts in hydrocarbon cracking and organic reactions, among other applications.

Abstract: A method for production of high purity silica sols comprising the steps: (a) adding a phosphonic acid-based complexing agent to the silicic acid-containing solution forming complexes with metal cations present in said solution; (b) forming in said silicic acid-containing solution a precipitation containing phosphonic acid-based complexing agent and metal cations; (c) removing the precipitation from the solution; and, (d) polymerising the silicic acid in the solution to obtain a silica sol. The invention also relates to silica sols containing at least one phosphonic acid-based complexing agent.

Abstract: Silica particles for incorporation into a dentifrice composition, preferably as a thickening agent, have a polyether glycol such as polyethylene glycol applied thereto in order to enhance dentifrice cohesion

Abstract: The invention relates to a novel process for the preparation of precipitated silica which can be used as a reinforcing filler for elastomers. The invention also relates to novel precipitated silicas in the form of powder, granules or, preferably, substantially spherical beads, these silicas being characterized in that they have a BET specific surface of between 185 and 250 m2/g, a CTAB specific surface of between 180 and 240 m2/g, and a pore distribution such that the pore volume V2 made up of the pores with a diameter of between 175 and 275 Å represents less than 50% of the pore volume V1 made up of the pores with diameters of less than or equal to 400 Å, a pore volume (Vd1), made up of the pores with a diameter of less than 1 &mgr;m, of greater than 1.65 cm3/g, a fineness value (F.V.) of between 70 and 100 Å, and a content of fines (&tgr;f), after deagglomerability with ultrasound, of at least 50%.

Abstract: Disclosed is an alkoxysilane/organic polymer composition for use in producing an insulating thin film, comprising (A) a specific alkoxysilane; (B) a specific organic polymer; and (C) a solvent for alkoxysilane (A) and organic polymer (B), wherein solvent (C) comprises at least one organic solvent selected from the group consisting of amide linkage-containing organic solvents and ester linkage-containing organic solvents. Also disclosed are a silica-organic polymer composite thin film which is produced by a process comprising: forming a thin film of the composition of the present invention; subjecting the thin film to a hydrolysis and dehydration-condensation reaction with respect to the alkoxysilane thereof, to thereby cause the alkoxysilane to be gelled in the thin film; and removing the solvent remaining in the thin film by drying, and a porous silica thin film which is obtained by removing the organic polymer from the silica-organic polymer composite thin film.

Abstract: Silica compositions for abrasive systems in dentifrice formulations are disclosed. The silica abrasive system comprises (a) silica gels having a median particle size below 7 microns, a pH of from about 6 to about 11 and powder RDA's of from 100 to about 200 and (b) silica gels or precipitates having a median particle size of 7 microns or greater and powder RDA's of from 50 to about 180. Silica (a) is preferably prepared by contacting a hydrous silica gel with an alkaline medium. Dentifrice compositions comprising the abrasive system has an RDA of 150 or less and PCR's of at least 80 and up to about 150, and an REA of less than about 30 (as measured on the IU scale).

Abstract: Disclosed herein is a method of preparing silica slurry for wafer polishing. This method includes pre-treating relatively inexpensive and commercially available fumed or colloidal silica particles as a seed by a settling, a crushing using a ball mill and a paint shaker, and a sonication to produce an aqueous dispersion of the silica particles. The pre-treated silica particles are then combined with tetraethylorothosilicate as a precursor, an alcohol solvent and a base, and grown to a desired size by hydrolysis and polycondensation of the precursor, tetraethylorothosilicate. Then, the alcohol solvent, in which the silica particles are grown, are displaced with water by a vacuum distillation. The resulting aqueous dispersion of the grown silica dispersion is hydrothermally treated in an autoclave. Thus, this method allows the economical preparation of the spherical silica particles having a highly uniform size and a very high purity.

Abstract: Abrasive compositions comprised of water-insoluble abrasive polishing agents suspended in a liquid medium in combination with humectant, and methods for making same. The inventive abrasive compositions are rheologically stable, settling-resistant, and re-agglomeration resistant, even during and after transport and/or storage before end-use, such as incorporation into dentifrice formulations or other oral cleaning compositions. The high settling-resistance of the inventive abrasive composition makes it possible to avoid the need before end use for temporary stabilizers such as inorganic suspending agents (e.g., clays, fumed silicas) or organic binders (e.g., polysaccharides). Also, the abrasive compositions contain abrasive particles having improved brightness as compared to abrasive particles made via drying and dry comminution processing.

Abstract: This invention relates to a new synthetic crystalline material comprising acidic surface silanol groups, designated MCM-69, a method for its preparation and use thereof in catalytic conversion of organic compounds.

Abstract: Methods of making dentifrice compositions including, as a raw material ingredient thereof, abrasive compositions comprised of water-insoluble abrasive polishing agents suspended in a liquid medium in combination with humectant, and the unique dentifrice compositions made in this manner.

Abstract: An amorphous silica having an RDA value of between 40 and 70, an oil absorption capacity of between 90 and 145 cc/100 g and a moisture loss of less than 7% w/w, can be incorporated at a 10% to 25% loading into a transparent toothpaste having a refractive index of below 1.445, this toothpaste having an RDA value of less than 60.

Abstract: The precipitated silica has the following physico-chemical parameters: BET surface area (DIN 66131) in m2/g 400-600 DBP index (DIN 53601) in g/100 g 300-360 Compacted density (DIN 53194) in g/l  70-140 Grindometer value (ISO 1524) in &mgr;m 15-50 Size distribution index I <1.0 measured with a Malvern instrument Size distribution index I = d 90 - d 10 2 ⁢ d 50 This precipitated silica is prepared by milling a precipitated silica in accordance with DE-A 31 44 299 in a classifier mill or a fluidized bed counter-flow mill. A polyethylene wax emulsion may be added before the milling procedure.

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: The precipitated silica has the following physico-chemical parameters: BET surface area (DIN 66131) in m2/g 400-600 DBP index (DIN 53601) in g/100 g 300-360 Compacted density (DIN 53194) in g/l  70-140 Grindometer value (ISO 1524) in &mgr;m 15-50 Size distribution index I <1.0 measured with a Malvern instrument Size ⁢   ⁢ distribution ⁢   ⁢ index ⁢   ⁢ I = d 90 - d 10 2 ⁢ d 50 This precipitated silica is prepared by milling a precipitated silica in accordance with DE-A 31 44 299 in a classifier mill or a fluidized bed counter-flow mill.

Abstract: A dispersion comprising fine porous inorganic oxide particles, e.g., silica gel particles, wherein the particles have a median particle size below three microns. The dispersed particles have a porosity after drying in which at least about 0.50 cc/g of pore volume is from pores having a pore size of 600 Å or less as determined by nitrogen porosimetry. Embodiments prepared from silica gel have porosity after drying in which at least about 0.7 cc/g of pore volume is from pores having a diameter of 600 Å or smaller. The particles of the dispersion also can be described as having viscosity derived pore volume of at least about 0.5 g/cc. The dispersion is prepared by forming a dispersion from inorganic oxides having sufficient rigid structure to maintain porosity after milling and drying. After the inorganic oxide is selected, it is milled to have a median particle size of 0.05 to about 3 microns.

Abstract: The present invention provides the amorphous silica particles having a double structure of a core of the dense amorphous silica and a shell of the bulky amorphous silica, having a volume-based median diameter of from 1 to 5 &mgr;m and containing not more than 10% by volume of fine particles having a particle diameter of not larger than 0.5 &mgr;m. The amorphous silica particles of the double structure have constant particle diameters not only in the powdery state but also in a state where they are blended in a coating material or in a resin, without developing fine particles, exhibit excellent delustering action and antiblocking action, exhibit decreased abrading property, and exhibit excellent resistance against scars or abrasion.

Abstract: Non-spherical silica particles having nodular morphology for use as an abrasive media in chemical mechanical polishing are disclosed. Also disclosed are aqueous slurries of monodispersed non-spherical nodular shaped particles having mean effective diameters between about 100 and 300 nanometers for chemical mechanical polishing. In addition aqueous slurries for the chemical mechanical polishing and planarization of oxide dielectric, metal, and metal/metallic compound interlayers of integrated circuits are disclosed.

Abstract: A process for the preparation of mesostructured molecular sieve silicas from inorganic silicon precursors and polyoxyethylene oxide based polymers is described. The silicas are stable upon calcination to 600° to 800° C. The silicas are useful in refining processes.

Abstract: A process and system for removing heavy metals, fluoride, silica and other contaminants from large volumes of wastewater is disclosed. In the process, a wastewater stream containing the contaminant is treated with a chemical coagulant to create a particle having a diameter greater than 5 microns. Treated wastewater is passed through a microfiltration membrane which physically separates the metal contaminant particle from the wastewater. Commercially available microfiltration membranes having a pore size from 0.5 micron to 5 microns may be used. The treated wastewater flow rate through the microfiltration membranes can range from 700 gallons per square foot of membrane per day (“GFD”) to 1500 GFD. Solids are removed from the membrane surface by periodically backflushing the micro-filtration membranes and draining the filtration vessel within which the membranes are located. The dislodged solid material within the filtration vessel is flushed into a holding tank for further processing of the solids.

Abstract: Silica compositions for abrasive systems in dentifrice formulations are disclosed. The silica abrasive system comprises (a) silica gels having a median particle size below 7 microns, a pH of from about 6 to about 11 and powder RDA's of from 100 to about 200 and (b) silica gels or precipitates having a median particle size of 7 microns or greater and powder RDA's of from 50 to about 180. Silica (a) is preferably prepared by contacting a hydrous silica gel with an alkaline medium. Dentifrice compositions comprising the abrasive system has an RDA of 150 or less and PCR's of at least 80 and up to about 150, and an REA of less than about 30 (as measured on the IU scale).

Abstract: A high cleaning low abrasion dentifrice containing a silica hydrogel having a mean particle size from about 5 to about 11 microns; an Einlehner hardness of from 1 to about 20; an oil absorption of about 40 to less about 100 cc/g, a BET surface area from 100 to 700 m2/g of silica, the particles having a morphology characterized by glass conchoidal fracture surfaces whereby, the dentifrice composition has a RDA of 110 to 200 and a PCR from about 150 to about 300.

Abstract: Essentially spherical precipitated silica beads, well adapted for the reinforcement of elastomeric matrices, have a mean particle size of at least 80 &mgr;m, a BET specific surface area ranging from 60 to 130 m2/g, a fill density in packed state ranging from 0.28 to 0.37, and a total pore volume ranging from 1.6 to 3.3 cm3/g.

Abstract: The present invention relates to a process for easily and efficiently producing silica particles having a narrow particle size distribution and a high porosity from inexpensive starting materials such as sodium silicate. The silica particles of the present invention can be obtained in the form of a slurry containing them by (1) forming a slurry by mixing first particles difficultly soluble in an alkali and soluble in an acid, with an aqueous alkali silicate solution to form a first slurry containing the first particles, (2) neutralizing the first slurry with a mineral acid to prepare a second slurry containing second particles wherein silica is deposited on the first particles, and (3) adding a mineral acid to the second slurry to dissolve the first particles from the second particles, to prepare a third slurry containing silica particles.

Abstract: Precipitated silica having the following parameters: BET surface area 80-180 m2/g CTAB surface area 80-139 m2/g BET/CTAB ratio 1.0-1.6 Sears No. (consumption of 5-25 ml 0.1 N NaOH) DBP No. 200-300 ml/100 g Al2O3 content <5% wk coefficient <3.4 Degraded particles <1.0 &mgr;m Non-degradable particles 1.0-100 &mgr;m is prepared by reacting alkali silicate with mineral acids and aluminum sulfate solution at temperatures of 60-95° C. at a pH of 7.0-10.0 while stirring constantly, wherein the reaction is continued to a solids concentration of 40-110 g/l, the pH is adjusted to a value between 3 and 5, and the precipitated silica is filtered off, washed and then dried, and optionally ground or granulated.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a very good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 100 and 240 m2/g, a DOP oil uptake lower than 300 ml/100 g, a pore distribution such that the pore volume consisting of the pores whose diameter is between 175 and 275 Å represents less than 50% of the pore volume consisting of the pores of diameters which are smaller than or equal to 400 Å, a median diameter, after disintegration with ultrasound, smaller than 5 &mgr;m and an aluminum content of at least 0.35% by weight. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers.

Abstract: A method for preparing hollow particles comprising a dense silica shell, by precipitating active silica from an aqueous alkaline metal silicate on a core constituted in a material other than silica and by eliminating the material without destroying the silica shell. The particles are used as insulating materials; as hollow fillers for polymers, building materials, rubber, paper, paint; as absorbing agents; as toothpaste abrasives or additives; as support for the absorption and/or graining out active matter, the liberation of the active matter being effected by the destruction of the silica core by mechanical rupture or by dissolving the silica shell in a basic medium or by diffusion; as sun screening agents or sun screening agent supports or for the formulation of liquid matter in solid form.

Abstract: A partially hydrophobic precipitated silica having a methanol wettability of 10 to 49%, in particular with a DBP uptake on a dry basis of greater than 250 g/100 g and a mean particle size of 1 to 12 &mgr;m and/or a carbon content of 0.3 to 1.85% and/or a loss on drying of 2.6 to 10.0% and/or a pH value of 5.5 to 10.0, is prepared by mixing the amount of water-repellent agent with the precipitated silica suspension at very short residence time and low pH value, filtering off the solid substance, washing free of salt, drying, post-treating thermally and milling. The partially hydrophobic precipitated silica can be used in active substance formulations and active substance formulations of hydrolysis-sensitive substance and in defoaming agents.

Abstract: The invention discloses an abrasive precipitation silica useable in toothpaste compositions, said silica having a BET specific surface ranging from 15 to 300 m2/g, a DOP oil absorption ranging from 40 to 160 ml/g, a median particle diameter of at least 10 &mgr;m, generally ranging from 12 to 30 &mgr;m, a particle cohesion factor of at least 85% about for a median particle diameter ranging from 12 to 20 &mgr;m.

Abstract: An amorphous silicate pigment having a pore volume of at least about 4.0 ml/g as measured by mercury intrusion, a BET surface area of at least about 300 m2/g, and an Al2O3 content of about 2.0-10.0 wt % is provided. The invention can be successfully used in recording media coatings, particularly coatings for recording media used in ink jet printing systems.

Abstract: Essentially spherical silica-based granular particulates, whether having a mean particle size of at least 300 &mgr;m and a density of from 0.15 to 0.32, or a mean particle size of from 80 &mgr;m to 400 &mgr;m and a density of at least 0.32, are well adapted as reinforcing filler material for a variety of elastomeric matrices, e.g., rubber.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m.sup.2 /g, a BET specific surface of between 90 and 250 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a zinc content of between 1 and 5% by weight, and by the fact that the number N of stearic acid molecules consumed per nm.sup.2 of silica surface, when stearic acid is reacted with this silica in xylene for 2 hours at 120.degree. C., is at least 1. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers, especially for improving their rheological properties.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a pore distribution such that the pore volume consisting of the pores whose diameter is between 175 and 275 .ANG. represents less than 50% of the pore volume consisting of the pores of diameters smaller than or equal to 400 .ANG., a zinc content of between 1 and 5% by weight and by the fact that the number N of molecules of stearic acid consumed per nm.sup.2 of silica surface, when stearic acid is reacted with the said silica in xylene for 2 hours at 120.degree. C., is at least 1.

Abstract: A process for preparing compounds of the formulae I and II ##STR1## where R.sup.1 and R have the meanings indicated in the specification by an addition reaction of a compound of the formula IIIR.sup.1 OH IIIwith an acetylene or allene of the formula IV or V ##STR2## in the gas phase at elevated temperatures in the presence of a heterogeneous catalyst. The catalyst is obtained by impregnating silica with a zinc salt, by a process in which the reaction is carried out at below 200.degree. C. and the catalyst contains, as an active component, an X-ray amorphous zinc silicate or cadmium silicate containing from 1 to 40% by weight, calculated as oxide, of zinc or cadmium, obtainable by applying a salt of zinc or cadmium and an inorganic oxo acid, which salt is decomposable at below 400.degree. C., to amorphous silica and forming the catalyst before the reaction at from 50 to 500.degree. C. or during the reaction in situ at from 50 to 200.degree. C.

Abstract: Essentially spherical precipitated silica beads, well adapted for the reinforcement of elastomeric matrices, have a mean particle size of at least 80 .mu.m, a BET specific surface area ranging from 60 to 130 m.sup.2 /g, a fill density in packed state ranging from 0.28 to 0.37, and a total pore volume ranging from 1.6 to 3.3 cm.sup.3 /g.

Abstract: Process for preparing porous spherical silica particles substantially consisting in emulsifying an acidic silica sol in a dispersing media, gelifying the microdrops of the sol in the emulsified state and submitting the resulting gel to thermal treatment in the presence of the emulsifier liquid and of sol gelation base.

Abstract: A process for the preparation of high purity silane, suitable for forming thin layer silicon structures in various semiconductor devices and high purity poly- and single crystal silicon for a variety of applications, is provided. Synthesis of high-purity silane starts with a temperature assisted reaction of metallurgical silicon with alcohol in the presence of a catalyst. Alcoxysilanes formed in the silicon-alcohol reaction are separated from other products and purified. Simultaneous reduction and oxidation of alcoxysilanes produces gaseous silane and liquid secondary products, including, active part of a catalyst, tetra-alcoxysilanes, and impurity compounds having silicon-hydrogen bonds. Silane is purified by an impurity adsorption technique. Unreacted alcohol is extracted and returned to the reaction with silicon. Concentrated mixture of alcoxysilanes undergoes simultaneous oxidation and reduction in the presence of a catalyst at the temperature -20.degree. C. to +40.degree. C. during 1 to 50 hours.

Abstract: A three-dimensional composite of silica spheres interconnected by resin is provided having a three-dimensional network structure including silica particles having the following structural and dynamic characteristics and a resin present in the internal pores of said network:(a) three-dimensionally interconnected spherical silica particles having a diameter of 6 to 30 .mu.m;(b) on the surface of said spherical silica particles, a specific surface area of 300 to 400 m.sup.

Abstract: Disclosed is an improvement in the process for the preparation of amorphous silicic acid particles useful, for example, as a filtration aid comprising the steps of a hydrothermal reaction to prepare calcium silicate particles and decalcification of the calcium silicate particles, after or without undertaking carbonation by the reaction of carbon dioxide, with an acid to form particles of amorphous silicic acid followed by drying of the amorphous silicic acid particles.

Abstract: Dry, freely-flowing, water-insoluble but readily dispersible, solid and homogeneous silica pigment particulates essentially spheroidal in geometrical configuration and having a mean particle size in excess of 80.mu., preferably in excess of 150.mu., are prepared by atomizing to dryness a pulverulent aqueous suspension of silica having a solids contact in excess of 18%. Such silica pigment particulates, advantageously comprised of precipitated silica, are well adapted as reinforcing fillers for elastomeric matrices.

Abstract: Precipitated silica particulates suited for homogeneous incorporation, dispersion and distribution within vulcanized elastomeric matrices reinforced therewith can be formed as either a powder, substantially spherical beads, or granulates. The silica particulates have a CTAB specific surface ranging from 100 to 140 m.sup.2 /g, a median diameter .phi..sub.50, after ultrasonic disintegration, less than 2.8 .mu.m, an ultrasonic disintegration factor F.sub.D greater than 3 ml, a BET specific surface ranging from 100 to 200 m.sup.2 /g, a mean particle size greater than 15 .mu.m when formed as a powder, at least 80 .mu.m when formed a s substantially spherical beads, and at least 1 mm when formed as a granulate, a packing density in the tamped state of at least 0.17, and a DOP oil uptake ranging from 150 to 400 ml/100 g.

Abstract: A method of directly precipitating a spherical amorphous silica in a high yield by adding a carboxymethyl cellulose (CMC) as a coagulation growing agent in a step of neutralizing the alkali silicate with an acid. The CMC having a particular etherification degree and a particular polymerization degree is added in an amount of from 1 to 100% by weight reckoned as SiO.sub.2 with respect to silica in the alkali silicate, whereby the whole silica particles turn into spherical amorphous silica particles having high sphericalness. There can be obtained spherical amorphous silica particles having a BET specific surface area of from 25 to 800 m.sup.2 /g, an apparent specific gravity of from 0.1 to 0.8 and a particle diameter of from 0.2 to 50 .mu.m cheaply and in a high yield.

Abstract: Silica compatible with flavors, exhibiting, at an RP/DA abrasivity lower than or equal to 10, a compatibility with flavors which is higher than 10% and, at an RP/DA abrasivity higher than 10, a compatibility with flavors of at least 30%. Process for the preparation of flavor-compatible silica by treating the surface of a silica originating from the reaction of an alkali metal silicate with an inorganic or organic acidic agent, the silica being in dry form or in an aqueous suspension, with the aid of an organic compound capable of developing hydrogen bonds or ionic bonds with, respectively, the Si--OH silanol groups or the SiO.sup.- anionic groups at the surface of the said silica to be treated, the said treated silica being subsequently, if necessary, isolated and/or washed and/or dried. Use in dentifrice compositions and dentifrice compositions including the said silica.

Abstract: Precipitated silica particulates having a BET specific surface ranging from 20 to 300 m.sup.2 /g, a CTAB specific surface ranging from 10 to 200 m.sup.2 /g, an oil uptake (DBP) ranging from 80 to 400 cm.sup.3 /100 g, a pore volume ranging from 1 to 10 cm.sup.3 /g and a mean pore diameter ranging from 10 to 50 nm, well adapted for such applications as the coating of paper and catalysis, are prepared by (a) simultaneously introducing a silicate and an acid into a dispersion of colloidal silica, thereby providing a silica suspension, (b) next decreasing the pH of such suspension to a value ranging from 3 to 7, and (c) then separating the silica particulates from the final suspension and drying them.

Abstract: A process for preparation of silica pigment by mixing sea water and an aqueous solution of sodium silicate is disclosed, in which no acidulating agent is used and the amount of sea water is 50-500 times of the sodium silicate by weight.

Abstract: An amorphous silica having an RDA value of between 30 and 70, an oil absorption capacity of between 100 and 155 cc/100 g and a moisture loss of less than 7% w/w, can be incorporated at a 10% to 25% loading into a transparent toothpaste having a refractive index of above 1.445, this toothpaste having an RDA value of between 30 and 60.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m.sup.2 /g, a BET specific surface of between 90 and 250 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a zinc content of between 1 and 5% by weight, and by the fact that the number N of stearic acid molecules consumed per nm.sup.2 of silica surface, when stearic acid is reacted with this silica in xylene for 2 hours at 120.degree. C., is at least 1. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers, especially for improving their rheological properties.

Abstract: The method for producing a bulk silica porous material is presented. The obtained material has a large crystal size serving to reduce light scattering, and uniform and adjustable pore size. This can be utilized for optical and electronic functional materials. The method comprises the steps of:forming a silica/surfactant composite by mixing starting materials containing an alkoxysilane, water and a surfactant and allowing to the starting materials to react;maturing said silica/surfactant composite by allowing the same to stand in a closed container to effect the development of a silica network structure and the formation of porous structure in said composite;drying said matured silica/surfactant composite for removing the solvent and for condensation of said matured silica/surfactant composite; and,sintering said condensed silica/surfactant composite to remove the surfactant to obtain a silica porous material.

Abstract: Oral compositions, such as oral gels and toothpastes, containing a novel high cleaning, low abrasion silica hydrogel abrasive.