Ppg Industries, Inc.

Agaram S Abhiraman

Desaraju V Varaprasad

Ernest L Lawton

A wet and dry jet wet spinning process produce one or a plurality of siliceous-containing fibers. At least a partial hydrolyzate is formed from silicon alkoxides and/or colloidal dispersions of hydrolyzable metal oxides through acid catalyzed hydrolysis in the presence of a solvent. The ratio of amounts of the water to silicon alkoxide or hydrous oxide is around 1.5 to 1 up to less than around 4 to 1. Both the hydrolysis and polymerization reactions produce an ungelled hydrolyzate with a viscosity in the range of 70 to greater than 1000 poise. This hydrolyzate is extruded through a spinnerette into a gaseous environment for dry jet wet spinning followed by contacting with a nonsolvent liquid or directly into a nonsolvent liquid for wet spinning. The contacting with the nonsolvent liquid is for effective coagulation to produce cohesive fiber that may have some stickiness. The fiber is removed from the nonsolvent liquid where the fiber's length is continuous from the spinnerette to removal. The continuous fiber is collected when it has at least a coagulated surface to produce a predominantly nonsticky fiber. The fiber may be utilized as precursor fiber or further processed by washing and/or stretching and/or drying and/or heating for removal of water, and organic solvent and/or consolidating of the fiber.

Spinning of sol gel siliceous-containing fibers with wet coagulation

A sol gel reaction process for forming glassy articles involves the hydrolysis of silicon alkoxides with or without additional dispersions of hydrated silicon oxides, and polymerization including crosslinking. The present process involves forming glassy articles by the sol gel reaction route utilizes coagulation promoters having fatty acid hydrophobic moieties and hydrophilic moieties of primary, secondary, tertiary amines or quaternary ammonium compounds. The coagulation promoter catalyzes either and/or both of the hydrolysis and polymerization reactions. The coagulation promoter can be the only catalyst in forming the sol or can be used in addition to acid or basic catalyst. Additionally or alternatively, the coagulation promoter is added to a coagulation fluid to which shaped hydrolyzate is added. Afterwards the gelled shape precursor is optionally consolidated to form a precursor glass shape and optionally is consolidated to form the glassy shapes of films, coatings, beads, fibers, tubes and monolithic structures.

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Stone Mountain, GA, United States of America

Agaram S Abhiraman