Abstract: A lost circulation material (LCM) is provided having a nanosilica dispersion and an alkanolamine. The nanosilica dispersion and the alkanolamine may form a gelled solid after interaction over a period. Methods of lost circulation control using LCMs are also provided.

Abstract: A method for producing and using an ultrapure colloidal silica dispersion is disclosed. The ultrapure colloidal silica dispersion has less than 200 ppb of each trace metal impurity disposed therein, excluding potassium and sodium, and less than 2 ppm residual alcohol. The method comprises dissolving a fumed silica in an aqueous solvent comprising an alkali metal hydroxide to produce an alkaline silicate solution, removing the alkali metal via ion exchange to generate a silicic acid solution, adjusting temperature, concentration and pH of said silicic acid solution to values sufficient to initiate nucleation and particle growth, and cooling the silicic acid solution at a rate sufficient to produce the colloidal silica dispersion.

Abstract: To provide a process for producing a dispersion of hollow fine SiO2 particles which contains no residual core fine particles, generates no uncontrollable agglomerates, and is easy to filtrate.

Abstract: Provided is a cationized silica dispersion prepared by dispersing dry processed silica and a cationic resin in a polar solvent, wherein a concentration of dissolved silicic acid at 25° C. is 200 ppm or less. This cationized silica dispersion does not substantially form coagulated matters when blended with a binder and therefore can advantageously be used for producing a coating composition such as a coating composition for forming a gas barrier layer, a corrosion preventive coating composition and a coating composition for ink jet recording paper.

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: Provided is a cationized silica dispersion prepared by dispersing dry processed silica and a cationic resin in a polar solvent, wherein a concentration of dissolved silicic acid at 25° C. is 200 ppm or less. This cationized silica dispersion does not substantially form coagulated matters when blended with a binder and therefore can advantageously be used for producing a coating composition such as a coating composition for forming a gas barrier layer, a corrosion preventive coating composition and a coating composition for ink jet recording paper.

Abstract: A sol comprising silica-magnesium fluoride hydrate composite colloidal particles used in an anti-reflection coating material for forming an anti-reflection coating and a process for its preparation are provided. A sol comprising silica-magnesium fluoride hydrate composite colloidal particles having a ratio of silica to magnesium fluoride hydrate MgF2.nH2O, n being in the range between 0.25 and 0.5, in terms of a SiO2/MgF2 weight ratio of from 0.01 to 5 and a primary particle size of 5 to 50 nm. A process for the preparation of an aqueous sol comprising silica-magnesium fluoride hydrate composite colloidal particles which comprises the steps of adding an aqueous fluoride solution to a mixture liquid of a silica sol and an aqueous magnesium salt solution to produce a slurry of an agglomerate comprising silica-magnesium fluoride hydrate composite colloidal particles and removing the salts formed as by-products.

Abstract: The invention relates to an aqueous silica-based sol comprising a nitrogen-containing organic compound and silica-based particles with a specific surface area of at least 300 square meters per gram of silica. The invention further relates to a process for the production of an aqueous silica-based sol comprising a nitrogen-containing organic compound which comprises incorporating a nitrogen-containing organic compound into a silica-based sol containing silica-based particles with a specific surface area of at least 300 square meters per gram of silica. The invention also relates to the use of an aqueous silica-based sol comprising a nitrogen-containing organic compound and silica-based particles with a specific surface area of at least 300 square meters per gram of silica as a flocculating agent in the production of pulp and paper and in water purification.