Back to results
US 2004/0116270 A1Published application
Glass prepared from pyrogenically prepared silicon dioxide
AssigneeDegussa AG
InventorsMonika Oswald, Gerrit Schneider, Klaus Deller
Life of this patent
Estimating the term…
Abstract
Pyrogenically prepared silicon dioxide with the following physicochemical properties: 1. Average particle size (D50 value) D50≧150 nm (dynamic light scattering, 30 wt %) 2. Viscosity (5 rpm, 30 wt %)η≦100 m·Pas 3. Thixotropy of Ti(η(5 rpm))/(η(50 rpm))≦2 4. BET surface area 30-60 m2/g 5. Compacted bulk=100-160 g/L 6. Original pH≦4.5 that can be used for the preparation of dispersions and glass bodies.
Claims10
A method of making glass comprising:
- forming a dispersion of a pyrogenic silica with water, by mixing said pyrogenic silica with water,
- gelling the dispersion,
- drying the dispersion to obtain a microporous body,
- sintering the body at a sufficient temperature for a sufficient time to produce a sintered glass body.
1 more element
A method of making a sintered glass comprising:
- mixing a pyrogenically prepared silicon dioxide with water to form a homogeneous dispersion, said pyrogenically prepared silicon dioxide having the following physicochemical properties:
- a) average particle size (D50 value) D50≧150 nm (dynamic light scattering, 30 wt %);
- b) viscosity (5 rpm, 30 wt %) η≦100 m·Pas;
- c) thixotropy of Ti:(η(5 rpm))/(η(50 rpm))≦2;
- d) BET surface area 30-60 m2/g;
- e) compacted bulk=100-160 g/L;
- and
- f) original pH≦4.5.
- pouring the dispersion into a mold,
- gelling the dispersion in the mold to form a gelled body,
- removing the gelled body from the mold, and
- drying the gelled body to form a microporous green body,
- sintering the green body by zone;
- sintering under vacuum to thereby obtain a sintered glass body.
11 more elements
Dependencies are inferred from the claim text.