초록

There is provided a method for making hollow microspheres including heating a feed under conditions sufficient to convert at least a portion of the feed into hollow microspheres, where the heating is conducted under a vacuum. There is also provided hollow microspheres made using this method.

대표청구항 ▼

1. A method of forming hollow microspheres comprising heating a feed under conditions sufficient to convert at least a portion of the feed into hollow microspheres, wherein the heating is conducted under a vacuum; further comprising providing the feed using a dispensing system, the dispensing system

1. A method of forming hollow microspheres comprising heating a feed under conditions sufficient to convert at least a portion of the feed into hollow microspheres, wherein the heating is conducted under a vacuum; further comprising providing the feed using a dispensing system, the dispensing system comprising an elongated housing having a hollow inner tube vertically centered therein; fluidizing the feed in the elongated housing; and introducing the feed into the hollow inner tube using a carrier gas. 2. A method according to claim 1 wherein the hollow inner tube has a top end and a bottom end, wherein the top end and bottom end are completely open. 3. A method according to claim 1 wherein the hollow inner tube has a top end and a bottom end, and further wherein a vertically extending protrusion extends from the top of the elongated housing to just above the top end of the hollow inner tube. 4. A method according to claim 1 further comprising collecting formed hollow microspheres in a collector. 5. A method according to claim 1 wherein the vacuum is maintained at equal to or less than 6,773 Pa (2 in Hg) absolute. 6. A method according to claim 1 wherein the vacuum is maintained at equal to or less than 33,864 Pa (10 in Hg) absolute. 7. A method according to claim 1 wherein the feed comprises at least one selected from glass, recycled glass, and perlite. 8. A method according to claim 1 wherein the feed comprises (a) between 50 wt % and 90 wt % of SiO2;(b) between 2 wt % and 20 wt % of alkali metal oxides;(c) between 1 wt % and 30 wt % of B2O3;(d) between 0 wt % to 0.5 wt % of sulfur;(e) between 0 wt % and 25 wt % divalent metal oxides;(f) between 0 wt % and 10 wt % of tetravalent metal oxides other than SiO2;(g) between 0 wt % and 20 wt % of trivalent metal oxides;(h) between 0 wt % and 10 wt % of oxides of pentavalent atoms; and(i) between 0 wt % and 5 wt % fluorine. 9. A method according to claim 1 further comprising heating the feed to a temperature greater than or equal to the softening temperature of the feed.