Low density glass particles with low boron content

Patent metadata

Field	Value
Publication number	US-9540276-B2
Application number	US-201314401411-A
Country	US
Kind code	B2
Filing date	May 14, 2013
Priority date	Jun 6, 2012
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

Glass particles comprise glass microbubbles. The glass particles have a size distribution with a d 50 in the range of from 15 to 100 microns, and have a true density of less than 0.7 g/cm 3 . The glass particles comprise, on an equivalent weight basis: from 50 to 70 weight percent silica; from 2 to 7 weight percent of boria; from 0.5 to 4 weight percent of weight zinc oxide; from 8 to 17 weight percent of calcia; from 0.8 to 7 weight percent of phosphorus pentoxide; and from 2 to 9 weight percent of sodium oxide.

First claim

What is claimed is:

1. Glass particles comprising glass microbubbles, wherein the glass particles have a size distribution with a d 50 in the range of from 15 to 100 microns, wherein the glass particles have a true density of less than 0.7 g/cm 3 , and wherein the glass particles comprise, on an equivalent weight basis: from 50 to 70 percent of silica, from 4 to 5 percent of boria, from 0.5 to 4 percent of zinc oxide, from 8 to 17 percent of calcia, from 0.8 to 7 percent of phosphorus pentoxide, greater than zero and less than 5 percent of alumina, and from 2 to 9 percent of sodium oxide.

2. Glass particles according to claim 1 , wherein the glass particles are loosely packed.

3. Glass particles according to claim 1 , wherein, on an equivalent basis, the glass particles comprise less than 10 percent of titania and zirconia combined.

4. Glass particles according to claim 1 , wherein the glass particles have an 80 percent crush strength of at least 3500 psi.

5. Glass particles according to claim 1 , wherein the glass particles have an 80 percent crush strength of at least 4000 psi.

6. Glass particles according to claim 1 , wherein the glass particles have an 80 percent crush strength of at least 4500 psi.

7. Glass particles according to claim 1 , wherein the glass particles have a true density of less than 0.6 g/cm 3 .

8. Glass particles according to claim 1 , wherein the glass particles have a true density of less than 0.5 g/cm 3 .

9. Glass particles according to claim 1 , wherein the glass particles have a d 95 less than 200 microns.

10. Glass particles according to claim 1 , wherein the glass microbubbles comprise at least 90 weight percent based on the total weight of the glass particles.

11. Glass particles according to claim 1 , wherein the glass microbubbles comprise at least 95 weight percent based on the total weight of the glass particles.

12. Glass particles according to claim 1 , wherein the glass microbubbles comprise at least 99 weight percent based on the total weight of the glass particles.

Assignees

• 3M Innovative Properties Co

Inventors

• Qi Gang

Classifications

• C01P2006/10

  Solid density · CPC title

• C01P2004/51

  Particles with a specific particle size distribution · CPC title

• C03C3/083

  containing aluminium oxide or an iron compound · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C03C3/089

  containing boron · CPC title