High density thoria-silica-metal (III) oxide fibers

Claim 2

A SHAPED AND FIRED, CONTINUOUS THORIA-SILICA-ALUMINABORIA FIBER COMPRISING THORIA AND SILICA TOGETHER IN MAJOR AMOUNT WEIGHT RATIO OF 1.5: 1 TO 10: 1, TO 25 PERCENT BY WEIGHT OF ALUMINA AND BORIA TOGETHER IN MOLE RATIO OF ABOUT 3 : 1 AND 0 TO 2 PERCENT BY WEIGHT CR2O3.

Claim 3

A shaped and fired, continuous thoria-silica-alumina-boria fiber having a density of at least about 3.5 consisting of 55 to 90 percent thoria, 5-35 percent silica and 5 to 25 percent of oxides of aluminum and boron in a mole ratio of about 3 : 1.

Claim 4

A shaped and fired, continuous thoria-silica-alumina-boria fiber having a density of at least about 3.5 consisting of 55 to 90 percent thoria, 5-35 percent silica and 5 to 25 percent of oxides of aluminum and boron in a mole ratio of about 3 : 1.

Claim 5

A shaped and fired, continuous, transparent thoria-silica-alumina-boria fiber having a density of at least about 3.5 consisting of 60-84 percent thoria, 8-25 percent silica and 8 to 20 percent of alumina and boria combined in a mole ratio of about 3 : 1.

Claim 6

A shaped and fired, continuous, transparent thoria-silica-alumina-boria fiber having a density of at least about 3.5 consisting of 60-84 percent thoria, 8-25 percent silica and 8 to 20 percent of alumina and boria combined in a mole ratio of about 3 : 1.

Claim 7

A shaped and fired, continuous, transparent thoria-silica-alumina-boria fiber according to claim 3 having a density of about 6 grams per cubic centimeter.

Claim 8

A shaped and fired, flexible, continuous, transparent thoria-silica-alumina-boria fiber according to claim 3 having a molar ratio of alumina:boria:silica of 3 : 1 : 10 to 3 : 1 : 6.

Claim 9

A shaped and fired, flexible, continuous, transparent thoria-silica-alumina-boria fiber according to claim 5 having a molar ratio of alumina:boria:silica of 3 : 1 : 10.

Claim 10

A spinning solution comprising thoria, silica, alumina and boria in stable aqueous dispersion at concentrations of about 30-55 percent solids by weight in proportions by weight of 1.5 to 1 to 10 to 1 of thoria to silica and 5 to 25 percent alumina and boria in molar ratio of about 3 : 1, said solution having a viscosity of at least about 15,000 centipoises.

Claim 11

A spinning solution comprising thoria, silica, alumina and boria in stable aqueous dispersion at concentrations of about 30-55 percent solids by weight in proportions by weight of 1.5 to 1 to 10 to 1 of thoria to silica and 5 to 25 percent alumina and boria in molar ratio of about 3 : 1, said solution having a viscosity of at least about 15,000 centipoises.

Claim 12

A spinning solution according to claim 7 wherein the thoria is present in stable aqueous dispersion as thorium oxynitrate or oxychloride.

Claim 13

A spinning solution according to claim 7 wherein the alumina and boria are present in stable aqueous dispersion as boric acid-stabilized aluminum acetate.

Claim 14

A process for the production of a continuous fiber spinning solution comprising thoria, silica, alumina and boria in stable aqueous dispersions in proportions by weight of 1.5 to 1 to 10 : 1 of thoria to silica and 5 to 25 peRcent of oxides of alumina and boria in molar proportions of about 3 : 1, said process comprising the steps of A. preparing a sol by dispersing thorium hydroxide in a sufficient volume of water to give a concentration of 5 to 10 percent weight ThO2 with approximately one half the stoichiometric amount for complete reaction of an acid forming soluble salts of thoria; B. adding alumina and boria precursors and colloidal dispersion of silica to the previously prepared sol, comprising thorium oxysalt and C. concentrating the solution comprising thorium oxysalt, alumina and boria precursors and colloidally dispersed silica by removal of water therefrom until the residue reaches the viscosity of at least 15,000 centipoises at from 25* to 35* C. and contains from about 30 to 55 percent solids.

Claim 15

A process for the production of a continuous fiber spinning solution comprising thoria, silica, alumina and boria in stable aqueous dispersions in proportions by weight of 1.5 to 1 to 10 : 1 of thoria to silica and 5 to 25 peRcent of oxides of alumina and boria in molar proportions of about 3 : 1, said process comprising the steps of A. preparing a sol by dispersing thorium hydroxide in a sufficient volume of water to give a concentration of 5 to 10 percent weight ThO2 with approximately one half the stoichiometric amount for complete reaction of an acid forming soluble salts of thoria; B. adding alumina and boria precursors and colloidal dispersion of silica to the previously prepared sol, comprising thorium oxysalt and C. concentrating the solution comprising thorium oxysalt, alumina and boria precursors and colloidally dispersed silica by removal of water therefrom until the residue reaches the viscosity of at least 15,000 centipoises at from 25* to 35* C. and contains from about 30 to 55 percent solids.

Claim 16

Process according to claim 10 wherein the alumina and boria precursor is boric acid-stabilized aluminum acetate.

Claim 17

Process for production of continuous fibers of thoria, silica, alumina and boria comprising the steps of A. extruding through orifices into air, at a relative humidify of less than 50 percent, a viscous aqueous dispersion of thorium oxysalt, colloidal silica and alumina and boria precursors in proportions such that ThO2, SiO2, and Al2O3 and B2O3 together as R2O3 in molar proportions of about 3 : 1 fall within the area of A, B, C, D, E of the drawing and at a rate such that continuous green fibers are produced and B. firing said green fibers in air up to a temperature of 700* to 1000* C. whereby high-density continuous fibers of thoria, silica, alumina and boria characterized by the presence of crystallites of thoria and densities of at least about 3.5 are produced.

Claim 18

Process for production of continuous fibers of thoria, silica, alumina and boria comprising the steps of A. extruding through orifices into air, at a relative humidify of less than 50 percent, a viscous aqueous dispersion of thorium oxysalt, colloidal silica and alumina and boria precursors in proportions such that ThO2, SiO2, and Al2O3 and B2O3 together as R2O3 in molar proportions of about 3 : 1 fall within the area of A, B, C, D, E of the drawing and at a rate such that continuous green fibers are produced and B. firing said green fibers in air up to a temperature of 700* to 1000* C. whereby high-density continuous fibers of thoria, silica, alumina and boria characterized by the presence of crystallites of thoria and densities of at least about 3.5 are produced.

Claim 19

Process according to claim 12 wherein thorium oxysalt is thorium oxynitrate and alumina and boria precursor is boric acid-stabilized aluminum acetate.

Claim 20

A fabric composed of shaped and fired, continuous thoria-silica-alumina and boria fibers comprising thoria and silica together in major amount and alumina and boria together in minor amount.

Claim 21

A fabric composed of shaped and fired, continuous thoria-silica-alumina and boria fibers comprising thoria and silica together in major amount and alumina and boria together in minor amount.