GLASS BUBBLES, COMPOSITES THEREFROM, AND METHOD OF MAKING GLASS BUBBLES

摘要

The present disclosure provides a plurality of glass bubbles having an average true density of up to about 0.55 grams per cubic centimeter and a size distribution including a median size in a range from about 15 micrometers to 40 micrometers. A hydrostatic pressure at which ten percent by volume of the plurality of glass bubbles collapses is at least about 100 megapascals. In some embodiments, the plurality of glass bubbles is a graded fraction preparable by classifying a second plurality of glass bubbles, wherein the second plurality of glass bubbles has a higher percentage of glass bubbles with a size of up to ten micrometers than the first plurality of glass bubbles. Composites including the plurality of glass bubbles are also disclosed.

主权项

1. A method of making a graded fraction of glass bubbles, the method comprising:
providing a second plurality of glass bubbles having a second size distribution comprising a median size, a number of glass bubbles up to ten micrometers in size, and a number of glass bubbles at least 40 micrometers in size; removing at least a portion of the glass bubbles at least 40 micrometers in size; removing at least a portion of the glass bubbles up to ten micrometers in size, wherein after removing at least a portion of the glass bubbles at least 40 micrometers in size and removing at least a portion of the glass bubbles up to ten micrometers in size, a first plurality of glass bubbles remains, wherein the first plurality of glass bubbles has a number of glass bubbles up to ten micrometers in size that is lower than the number of glass bubbles up to ten micrometers in size of the second plurality of glass bubbles, and wherein one of the following conditions is met: the first plurality of glass bubbles and the second plurality of glass bubbles have equivalent densities, but the first plurality of glass bubbles is higher in strength than the second plurality of glass bubbles; the first plurality of glass bubbles and the second plurality of glass bubbles have equivalent strengths, but the first plurality of glass bubbles is lower in density than the second plurality of glass bubbles; or the first plurality of glass bubbles is both lower in density and higher in strength than the second plurality of glass bubbles.