Hollow microspheres and method of making hollow microspheres

Patent metadata

Field	Value
Publication number	US-9266764-B2
Application number	US-201113996182-A
Country	US
Kind code	B2
Filing date	Dec 13, 2011
Priority date	Dec 20, 2010
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

There is provided a method for making hollow microspheres by means of dispensing the feed using vibratory energy, preferably ultrasonic energy, hollow microspheres made using the method, and an apparatus for making hollow microspheres.

First claim

What is claimed is:

1. A method of forming hollow microspheres comprising dispensing a feed with a dispenser, heating the feed using conditions sufficient to convert at least a portion of the feed into hollow microspheres, wherein the dispensing is conducted using vibratory energy, wherein the feed comprises
(a) between 50 wt % and 90 wt % of SiO 2 ;
(b) between 2 wt % and 20 wt % of alkali metal oxides;
(c) between 1 wt % and 30 wt % of B 2 O 3 ;
(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 SiO 2 ;
(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.

2. A method according to claim 1 wherein the vibratory energy is ultrasonic energy.

3. A method according to claim 1 wherein the hollow microspheres have a substantially single cell structure.

4. A method according to claim 1 wherein the dispensing is carried out by a dispenser selected from the group consisting of an ultrasonic horn and shaker.

5. A method according to claim 4 wherein the ultrasonic horn is further connected to a booster which is connected to a piezoelectric transducer.

6. A method according to claim 1 wherein the dispenser further comprises an elongated housing having a hollow inner tube vertically centered therein, and the feed is introduced into the hollow inner tube using a carrier gas.

7. A method according to claim 1 wherein the heating is provided under vacuum.

8. A method according to claim 7 wherein the vacuum is maintained at equal to or less than 6,773 Pa (2 inches Hg) absolute.

9. A method according to claim 1 wherein the feed is selected from at least one of glass, recycled glass, perlite, and combinations thereof.

10. A method according to claim 1 wherein the step of heating the feed using conditions sufficient to convert at least a portion of the feed into hollow microspheres comprises heating the feed to a temperature of greater than 1300° C.

Assignees

• Qi Gang
• Nayar Satinder K
• 3M Innovative Properties Co

Inventors

• Qi Gang
• Nayar Satinder K

Classifications

• C03B19/107 Primary

  Forming hollow beads (chemical aspects C03C11/002) · CPC title

• C03C11/002

  Hollow glass particles · CPC title

• C03C11/00

  Multi-cellular glass {; Porous or hollow glass or glass particles} · CPC title

• C03B19/10 Primary

  Forming beads · CPC title

• C03C12/00

  Powdered glass (C03C8/02 takes precedence); Bead compositions · CPC title