Patent US5273840A successfully refreshed from Google Patents.
US4336338A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hollow microspheres of silica glass and method of manufacture
Assignee: United States Department of Energy
•
Filing: 1980-08-15
•
Granted: 1982-06-22
•
Expires: 2000-08-15
Abstract
Abstract A method of manufacturing gel powder suitable for use as a starting material in the manufacture of hollow glass microspheres having a high concentration of silica. The powder is manufactured from a gel containing boron in the amount of about 1% to 20% (oxide equivalent mole percent), alkali metals, specifically potassium and sodium, in an amount exceeding 8% total, and the remainder silicon. Preferably, the ratio of potassium to sodium is greater than 1.5.
Inventors
- 👤 Raymond L. Downs
- 👤 Wayne J. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:54
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/10; C03B19/1005; C03B19/106; C03B19/1065; C03B19/107; C03B19/1075; C03C; C03C1/00; C03C1/006; C03C11/00; C03C11/002; Y; Y10; Y10S; Y10S65/00; Y10S65/901; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
119 words
A metal organic gel adapted for use as a starting material in the manufacture of hollow glass microspheres, said gel having an oxide equivalent glass composition consisting essentially of oxides of boron in the amount of about 4% to 10%, potassium in the amount of about 8% to 15%, sodium in the amount of about 1% to 10% and the remainder silicon, with a ratio of potassium to sodium in excess of 1.5, and which, when crushed and sieved to a particle size in the range of about 106 μm to 125 μm and formed into hollow glass microspheres at about 1500° C. in the presence of water vapor, is characterized by a silica concentration in excess of 99%.
Claim 2
Dependent Claim
119 words
A metal organic gel adapted for use as a starting material in the manufacture of hollow glass microspheres, said gel having an oxide equivalent glass composition consisting essentially of oxides of boron in the amount of about 4% to 10%, potassium in the amount of about 8% to 15%, sodium in the amount of about 1% to 10% and the remainder silicon, with a ratio of potassium to sodium in excess of 1.5, and which, when crushed and sieved to a particle size in the range of about 106 μm to 125 μm and formed into hollow glass microspheres at about 1500° C. in the presence of water vapor, is characterized by a silica concentration in excess of 99%.
Claim 3
Dependent Claim
46 words
The gel set forth in claim 1 wherein said oxide of boron is in the amount of about 6% to 7%, said oxide of potassium is in the amount of about 12% and said oxide of sodium is in the amount of about 2.5% to 3%.
Claim 4
Dependent Claim
93 words
In a method of making a gel particle suitable for use in the manufacture of hollow glass microspheres and which includes the step of forming a gel containing a mixture of glass-forming components, solvents and blowing agents, drying said gel and then crushing said gel, the improvement wherein said gel is formed to contain glass-forming components having an oxide equivalent composition including oxides of boron in the amount of about 6% to 7%, potassium in the amount of about 12%, sodium in the amount of about 2.5% to 3% and the remainder silicon.
Claim 5
Dependent Claim
93 words
In a method of making a gel particle suitable for use in the manufacture of hollow glass microspheres and which includes the step of forming a gel containing a mixture of glass-forming components, solvents and blowing agents, drying said gel and then crushing said gel, the improvement wherein said gel is formed to contain glass-forming components having an oxide equivalent composition including oxides of boron in the amount of about 6% to 7%, potassium in the amount of about 12%, sodium in the amount of about 2.5% to 3% and the remainder silicon.
Claim 6
Dependent Claim
58 words
The method set forth in claim 3 comprising the additional steps of sieving the crushed gel to obtain particles in the range of 106 μm to 125 μm and then forming said hollow glass microspheres by dropping said particles into an oven in the presence of water vapor at an oven temperature on the order of 1500° C.
Claim 7
Dependent Claim
32 words
In a hollow glass microsphere consisting essentially of oxides of silicon, boron, potassium and sodium, the improvement wherein the concentration in mole percent of said oxide of silicon is at least 99%.
Claim 8
Dependent Claim
32 words
In a hollow glass microsphere consisting essentially of oxides of silicon, boron, potassium and sodium, the improvement wherein the concentration in mole percent of said oxide of silicon is at least 99%.
Claim 9
Dependent Claim
51 words
A gel powder for manufacture of hollow glass microspheres having an oxide equivalent glass composition consisting essentially of oxides of boron in the range of about 6% to 7%, sodium in the amount of about 1% to 10%, potassium in the amount of about 5% to 25%, and the remainder silicon.
Claim 10
Dependent Claim
51 words
A gel powder for manufacture of hollow glass microspheres having an oxide equivalent glass composition consisting essentially of oxides of boron in the range of about 6% to 7%, sodium in the amount of about 1% to 10%, potassium in the amount of about 5% to 25%, and the remainder silicon.
Claim 11
Dependent Claim
66 words
A gel powder for manufacture of hollow glass microspheres having an oxide equivalent glass composition consisting essentially of oxides of boron in the range of about 6% to 7%, sodium in the amount of about 1% to 6%, potassium in the amount of about 8% to 15%, the mole ratio of oxide of potassium to oxide of sodium being greater than 1.5, and the remainder silicon.
Claim 12
Dependent Claim
66 words
A gel powder for manufacture of hollow glass microspheres having an oxide equivalent glass composition consisting essentially of oxides of boron in the range of about 6% to 7%, sodium in the amount of about 1% to 6%, potassium in the amount of about 8% to 15%, the mole ratio of oxide of potassium to oxide of sodium being greater than 1.5, and the remainder silicon.
Claim 13
Dependent Claim
49 words
A gel powder for manufacture of hollow glass microspheres having an oxide equivalent glass composition consisting essentially of oxides of boron in the range of about 6% to 7%, sodium in the amount of about 2.5 to 3%, potassium in the amount of about 12%, and the remainder silicon.
Claim 14
Dependent Claim
49 words
A gel powder for manufacture of hollow glass microspheres having an oxide equivalent glass composition consisting essentially of oxides of boron in the range of about 6% to 7%, sodium in the amount of about 2.5 to 3%, potassium in the amount of about 12%, and the remainder silicon.
Claim 15
Independent Claim
179 words
A method of manufacturing hollow microspheres having a uniform wall thickness and a silica concentration in excess of ninety-five mole percent comprising the steps of: (a) providing a gel powder by forming a metal organic gel having at least one blowing agent and an oxide-equivalent composition of glass forming components consisting essentially of oxides of boron in the range of about 1% to 20%, sodium in the amount of about 1% to 10%, other alkali metals selected from the group consisting of potassium, rubidium and cesium in the range of about 5% to 25%, the mole ratio of said other alkali metals to said sodium being in excess of 1.5, and the remainder silica, and then drying, crushing and sieving said gel to yield said gel powder, and (b) forming said hollow glass microspheres in a blowing operation by subjecting said gel powder to elevated temperature in the presence of water vapor to promote mutual volatilization of said oxides of boron, sodium and other alkali metals, and thereby yield said microspheres having a silica concentration in excess of 95%.
Claim 16
Independent Claim
179 words
A method of manufacturing hollow microspheres having a uniform wall thickness and a silica concentration in excess of ninety-five mole percent comprising the steps of: (a) providing a gel powder by forming a metal organic gel having at least one blowing agent and an oxide-equivalent composition of glass forming components consisting essentially of oxides of boron in the range of about 1% to 20%, sodium in the amount of about 1% to 10%, other alkali metals selected from the group consisting of potassium, rubidium and cesium in the range of about 5% to 25%, the mole ratio of said other alkali metals to said sodium being in excess of 1.5, and the remainder silica, and then drying, crushing and sieving said gel to yield said gel powder, and (b) forming said hollow glass microspheres in a blowing operation by subjecting said gel powder to elevated temperature in the presence of water vapor to promote mutual volatilization of said oxides of boron, sodium and other alkali metals, and thereby yield said microspheres having a silica concentration in excess of 95%.
Claim 17
Dependent Claim
45 words
The method set forth in claim 9 wherein said other alkali metals consist essentially of potassium, and wherein said oxide of sodium is in the amount of about 1% to 6% and said oxide of potassium is in the amount of about 8% to 15%.
Claim 18
Dependent Claim
15 words
The method set forth in claim 10 wherein said ratio is between 4 and 5.
Claim 19
Dependent Claim
33 words
The method set forth in claim 11 wherein said oxide of sodium is in the amount of about 2.5% to 3% and said oxide of potassium is in the amount of about 12%.
Claim 20
Dependent Claim
23 words
The method set forth in claim 10 or 12 wherein said oxide of boron is in the amount of about 4% to 10%.
Claim 21
Dependent Claim
21 words
The method set forth in claim 13 wherein said oxide of boron is in the amount of about 6% to 7%.
Claim 22
Dependent Claim
25 words
A hollow glass microsphere manufactured in accordance with the method set forth in claim 4 having a silica concentration in excess of 95 mole percent.
References Cited (Backward Citations)
US2286275A
Cited
US2883347A
Cited
US3030215A
Cited
US3365315A
Cited
US3489579A
Cited
US3699050A
Cited
US3826755A
Cited
US3843376A
Cited
US3782906A
Cited
US3839998A
Cited
US3799754A
Cited
US4021253A
Cited
US4017290A
Cited
JPS5134219A
Cited
US4059423A
Cited
US4133854A
Cited
US4257799A
Cited
US4257798A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |