Abstract: Colloidal silica having a controllable broad particle size distribution and a controllable minimum particle size is disclosed and claimed. Particles below a predetermined size are excluded from the product colloidal silica of the invention. A method for continuously producing the desired colloidal composition is disclosed comprising the steps of providing preformed silica particles having a surface area which controls the particle size of the colloidal silica product, adding a feed silica comprising an alkaline solution and silicate at a feed rate which is less than a nucleation rate.

Abstract: An easily dispersible cake of precipitated silica, wherein the precipitated silica has a BET specific surface area of at least 220 m2/g. When the cake is dispersed in ion-exchange water to provide an aqueous dispersion of the silica of 5% by weight in concentration and further diluted to reduce the silica concentration to 1.5% by weight, the dispersion has a light-scattering index (n-value) of at least 2. The easily dispersible cake can be obtained by simultaneously adding an alkali silicate and a mineral acid to a reaction liquid whose pH is being maintained at a fixed value within a range of 7.5-11.5 and whose temperature is being maintained at 92-98° C., thus forming precipitated silica through their reaction, and separating the precipitated silica from the reaction liquid in wet state.

Abstract: The present invention relates to a method of preparing a composition comprising mixing a silica sol having an S-value from about 5 to about 50% and a mineral acid. The invention also relates to a composition obtainable by the method and a composition comprising a network of silica particles and mineral acid, wherein the silica particles have a particle size of from about 2 to about 7 nm. The invention also relates to the use of the composition as a gelled electrolyte.

Abstract: Unique abrasive materials that are in situ generated compositions of precipitated silicas and silica gels are provided. Such compositions exhibit different beneficial, particularly simultaneously high pellicle film cleaning properties and moderate dentin abrasion levels. Such a result thus accords the user a dentifrice that effectively cleans tooth surfaces without detrimentally abrading such surfaces. Furthermore, the produced abrasive materials also exhibit very high and desirable brightness properties that permit easy incorporation and utilization within dentifrices for aesthetic purposes. Encompassed within this invention is a unique method for making such gel/precipitated silica composite materials for such a purpose, particularly under high shear conditions, as well as the different materials within the structure ranges described above and dentifrices comprising such.

Abstract: Unique abrasive and/or thickening materials that are in situ generated compositions of precipitated silicas and silica gels are provided. Such compositions exhibit different beneficial characteristics depending on the structure of the composite in situ generated material. With low structured composites (as measured via linseed oil absorption levels from 40 to 100 ml oil absorbed/100 g composite), simultaneously high pellicle film cleaning properties and moderate dentin abrasion levels are possible in order to accord the user a dentifrice that effectively cleans tooth surfaces without detrimentally abrading such surfaces. Increased amounts of high structure composite materials tend to accord greater viscosity build and thickening benefits together with such desirable abrasion and cleaning properties, albeit to a lesser extent than for the low structure types.

Abstract: Precipitated silica comprising porous silica particles having a cumulative surface area for all pores having diameters greater than 500 ? of less than 8 m2/g, as measured by mercury intrusion, and a percentage cetylpyridinium chloride (% CPC) Compatibility of greater than about 55%. The precipitated silica product is especially well-adapted for use in dentifrices containing cetylpyridinium chloride, which do not attach to the low surface area silica product in a meaningful level and thus remain available for antimicrobial action. Processes for making the silica product are also provided.

Abstract: The invention relates to the use of a composition for injection grouting obtainable by mixing an alkali metal silicate or an organic silicate, colloidal silica particles, and at least one gelling agent, wherein the weight ratio of colloidal silica to silicate is from about 2:1 to about 100:1. The invention also relates to a method of sealing a leaking part or cavity, and method of cutting off a liquid flow in a leaking part or cavity. The invention further relates to a composition for injection grouting and a method for preparing such composition.

Abstract: The present invention includes an apparatus for generating an inorganic polymer electret in a colloidal state, the inorganic electret in a colloidal state itself, and applications for the inorganic electret in a colloidal state. The invention includes a method for generation of a colloidal silica particle which is dipolar in that it is positively charged in the nucleus and negatively charged on the outer surface leaving a net negative charge to the particle. The apparatus includes the ability to control particle size, uniformity, consistency, hydration, and three dimensional structure which is desirable for various applications.

Abstract: Precipitated silica product having low surface area and enhanced flavor compatibility. The precipitated silica product is especially well-adapted for use in dentifrices containing cetylpyridinium chloride, which do not attach to the low surface area silica product in a meaningful level and thus remain available for antimicrobial action. Processes for making the low surface area silica product are also provided.

Abstract: A method for sealing rock or soil comprising inserting a sealing composition obtained by mixing a silica sol and at least one gelling agent, wherein the silica sol has an S-value higher than about 72%, a method for preparing the sealing composition and the composition obtained from the method.

Abstract: The present invention also provides a process for producing a colloidal dispersion of silica particle agglomerates having a specific surface area, as determined by nitrogen adsorption method, of 100 m2/g to 400 m2/g, an average secondary particle diameter of 20 nm to 300 nm and a pore volume of 0.5 ml/g to 2.0 ml/g, which comprises using a colloidal dispersion of silica particle agglomerates having a specific surface area, as determined by nitrogen adsorption method, of 300 m2/g to 1,000 m2/g and a pore volume of 0.4 ml/g to 2.0 ml/g as a seed dispersion, adding a feed solution comprising at least one of an aqueous active silicic acid solution and alkoxysilanes to the seed dispersion in small portions in the presence of an alkali to grow silica particle agglomerates.

Abstract: A stable aquasol comprising colloidal silica having a surface area of from about 700 m2/g to about 1100 m2/g, and an S- value of from about 20 to about 50; wherein said colloidal silica is not surface treated; wherein the molar ratio of SiO2/Na2O in said colloidal silica is greater than about 13.0:1 and is less than about 17.0:1; and wherein said aquasols have a percent by weight SiO2 solids level of from about 7.00 percent to about 16.80 percent is described and claimed.

Abstract: A stable aquasol containing colloidal silica having a surface area of from about 700 m2/g to about 1100 m2/g, and an S-value of from about 20 to about 50; wherein the colloidal silica is not surface treated; wherein the molar ratio of SiO2/Na2O in the colloidal silica is greater than about 13.0:1 and is less than about 17.0:1; and wherein the aquasols have a percent by weight SiO2 solids level of from about 7.00 percent to about 16.80 percent is described and claimed.

Abstract: Disclosed are stable, aqueous colloidal silicas having surface area of greater than 700 m2/g and S-values of from 20-50. These colloidal silicas do not require treatment with surface treatment agents such as aluminum to achieve stability. These colloidal silica aquasols can be produced and stored at concentrations of greater than 7 percent by weight SiO2 solids, and even as high as 15 percent by weight solids or higher, and remain stable at room temperature for at least 30 days compared to art-known silica aquasols. These colloidal silica sols demonstrate advantageously improved performance over art-known colloidal silica sots in applications such as in drainage and retention in papermaking processes. Also disclosed are processes for making aqueous colloidal silicas of the invention and the use of such colloidal silicas in papermaking processes.

Abstract: The present invention relates to a process for the preparation of organically modified aerogels, comprising a) the preparation of a silicic acid sol having a pH of ≦4.0 from an aqueous water glass solution, with the aid of at least one organic and/or inorganic acid; b) polycondensation of the resulting silicic acid sol to a SiO2 gel by the addition of a base; c) washing the gel obtained in Step b) with an organic solvent until the water content of the gel is ≦5% by weight; d) surface-silylating the gel obtained in Step c), and e) drying the surface-silylated gel obtained in Step d), characterized in that at least one acid forms difficultly soluble salts with the cations of the water glass in the silicic acid sol, and that before Step b) the resulting difficultly soluble salts are extensively precipitated and separated from the silicic acid sol.

Abstract: This invention relates to aggregates comprised of particles which contain silicon dioxide and to elastomers reinforced therewith. The invention also relates to tires having treads composed of such reinforced elastomers.

Abstract: A process is provided for the preparation of aqueous silica sols having a particle size of 27 to 72 nm. by adding fresh acidic silica sol into the reactors of a multi stage cascade reactor wherein the reactors contain aqueous solution of colloidal silica sol of a pH of 8 or above. Each successive stage of the cascade reactor is supplied with overflow from the preceding stage. Alkaline compounds, such as alkaline sodium silicate solution, alkaline potassium silicate solution, sodium hydroxide solution or potassium hydroxide solution, are introduced into the first reactor or first reactors so that a pH value in the range of 8 to 12.5 is established in the reactors.