Glass bubbles of increased collapse strength

Claim 2

Glass bubbles of average diameter between about 5 and 200 micrometers and average particle density of at least 0.4 gram/cubic centimeter consisting essentially of the following ingredients in the stated weight-percents: ______________________________________ SiO.sub.2 60-90 Alkali metal oxide 2-20 B.sub.2 O.sub.3 1-30 S 0.005-0.5 RO 0-25 RO.sub.2 (other than SiO.sub.2) 0-10 R.sub.2 O.sub.3 (other than B.sub.2 O.sub.3) 0-20 R.sub.2 O.sub.5 0-10 F 0-5 Other ingredients 0-2 ______________________________________

Claim 3

Glass bubbles of claim 1 having a density of at least 0.5 gram/cubic centimeter.

Claim 4

Glass bubbles of claim 1 having a softening point greater than about 750° C.

Claim 5

Glass bubbles of claims 1, 2 or 3 which include sulfur in an amount less than about 0.2 weight-percent.

Claim 6

Glass bubbles of claim 1, 2 or 3 which include sulfur in an amount less than about 0.1 weight-percent.

Claim 7

Glass bubbles of claim 1 which include at least 1 weight-percent of RO oxides.

Claim 8

Glass bubbles of claim 1 which include between about 2 and 10 weight-percent B 2 O 3 .

Claim 9

Glass bubbles of claim 1 which include at least 5 weight-percent of Na 2 O.

Claim 10

Glass bubbles of claim 1 having a Relative Strength of at least 30 percent.

Claim 11

Glass bubbles of claim 1 in which the stated ingredients are present within the following weight-percent ranges: ______________________________________ SiO.sub.2 65-85 Na.sub.2 O + K.sub.2 O + Li.sub.2 O 5-15 B.sub.2 O.sub.3 2-10 S 0.01-0.1 RO 1-15 RO.sub.2 (other than SiO.sub.2) 0-1 R.sub.2 O.sub.3 (other than B.sub.2 O.sub.3) 0-5 R.sub.2 O.sub.5 0-5 F 0-5 Other ingredients 0-2 ______________________________________

Claim 12

Injection-molded article comprising a polymeric matrix and bubbles of claim 1 dispersed in the matrix.

Claim 13

Extrusion-molded article comprising a polymeric matrix and bubbles of claim 1 dispersed in the matrix.

Claim 14

Cement product comprising a cementitious matrix and glass bubbles of claim 1 dispersed in the matrix.

Claim 15

Glass bubbles of claim 1 containing a gaseous fill under pressure.

Claim 16

Free-flowing mass of glass particles, at least 85 volume-percent of which are glass bubbles that float on water, said glass bubbles having an average diameter between about 5 to 200 micrometers and an average particle density of at least 0.4 gram/cubic centimeter, and consisting essentially of the following ingredients in the stated weight-percents: ______________________________________ SiO.sub.2 60-90 Na.sub.2 O + K.sub.2 O + Li.sub.2 O 2-20 B.sub.2 O.sub.3 1-30 S 0.005-0.5 RO 0-25 RO.sub.2 (other than SiO.sub.2) 0-10 R.sub.2 O.sub.3 (other than B.sub.2 O.sub.3) 0-20 R.sub.2 O.sub.5 0-10 F 0-5 Other ingredients 0-2 ______________________________________

Claim 17

Free-flowing mass of glass particles, at least 85 volume-percent of which are glass bubbles that float on water, said glass bubbles having an average diameter between about 5 to 200 micrometers and an average particle density of at least 0.4 gram/cubic centimeter, and consisting essentially of the following ingredients in the stated weight-percents: ______________________________________ SiO.sub.2 60-90 Na.sub.2 O + K.sub.2 O + Li.sub.2 O 2-20 B.sub.2 O.sub.3 1-30 S 0.005-0.5 RO 0-25 RO.sub.2 (other than SiO.sub.2) 0-10 R.sub.2 O.sub.3 (other than B.sub.2 O.sub.3) 0-20 R.sub.2 O.sub.5 0-10 F 0-5 Other ingredients 0-2 ______________________________________

Claim 18

Glass particles of claim 15 in which the glass bubbles have a density of at least 0.5.

Claim 19

Glass particles of claim 15 in which the bubbles have a softening point of at least 750° C.

Claim 20

Glass particles of claim 15, 16 or 17 in which the glass bubbles include sulfur in an amount less than about 0.2 weight percent.

Claim 21

Glass bubbles of claim 15, 16 or 17 in which the glass bubbles include sulfur in an amount less than about 0.1 weight-percent.

Claim 22

Glass particles of claim 15 which include at least 1 weight-percent of RO oxides.

Claim 23

Glass particles of claim 15 which include at least 5 weight-percent of Na 2 O.

Claim 24

Glass particles of claim 15 which include between about 2 and 10 weight-percent B 2 O 3 .

Claim 25

Glass particles of claim 15 in which the glass bubbles have a Relative Strength of at least 40 percent.

Claim 26

Glass particles of claim 15, 16 or 17 in which the stated ingredients are present within the following weight-percent ranges: ______________________________________ SiO.sub.2 65-85 Na.sub.2 + K.sub.2 O + Li.sub.2 O 5-15 B.sub.2 O.sub.3 2-10 S 0.01-0.2 RO 1-15 RO.sub.2 (other than SiO.sub.2) 0-1 R.sub.2 O.sub.3 (other than B.sub.2 O.sub.3) 0-5 R.sub.2 O.sub.5 0-5 F 0-5 Other ingredients 0-2 ______________________________________

Claim 27

Injection-molded article comprising a polymeric matrix and bubbles of claim 15 dispersed in the matrix.

Claim 28

Extrusion-molded article comprising a polymeric matrix and bubbles of claim 15 dispersed in the matrix.

Claim 29

Cement product comprising a cementitious matrix and glass bubbles of claim 15 dispersed in the matrix.

Claim 30

Glass bubbles of claim 15 containing a gaseous fill under pressure.

Claim 31

Free-flowing mass of glass particles, at least 85 volume-percent of which are glass bubbles that float on water, said glass bubbles having an average diameter between about 5 and 200 micrometers and an average particle density of at least 0.4 gram/cubic centimeter, and consisting essentially of the following ingredients in the stated weight-percent ranges: ______________________________________ SiO.sub.2 60-90 Na.sub.2 O + K.sub.2 O + Li.sub.2 O 2-20 B.sub.2 O.sub.3 2-10 S 0.005-0.2 RO 0-25 RO.sub.2 (other than SiO.sub.2) 0-10 R.sub.2 O.sub.3 (other than B.sub.2 O.sub.3) 0-20 R.sub.2 O.sub.5 0-10 F 0-5 Other ingredients 0-2 ______________________________________

Claim 32

Free-flowing mass of glass particles, at least 85 volume-percent of which are glass bubbles that float on water, said glass bubbles having an average diameter between about 5 and 200 micrometers and an average particle density of at least 0.4 gram/cubic centimeter, and consisting essentially of the following ingredients in the stated weight-percent ranges: ______________________________________ SiO.sub.2 60-90 Na.sub.2 O + K.sub.2 O + Li.sub.2 O 2-20 B.sub.2 O.sub.3 2-10 S 0.005-0.2 RO 0-25 RO.sub.2 (other than SiO.sub.2) 0-10 R.sub.2 O.sub.3 (other than B.sub.2 O.sub.3) 0-20 R.sub.2 O.sub.5 0-10 F 0-5 Other ingredients 0-2 ______________________________________

Claim 33

Glass particles of claim 29 in which sulfur is present in an amount less than 0.1 weight-percent.

Claim 34

Glass particles of claim 29 or 30 which include at least 1 weight-percent of RO oxides.

Claim 35

Glass particles of claim 29 or 30 in which the glass bubbles have a density of at least 0.5 gram/cubic centimeter.

Claim 36

Glass particles of claim 29 or 30 in which the glass bubbles have a relative strength of at least 30 percent.

Claim 37

Glass particles of claim 29 or 30 in which the glass bubbles have a softening point of at least 750° C.