US2973246A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making polishing material
Assignee: WR Grace and Co
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Filing: 1955-11-17
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Granted: 1961-02-28
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Expires: 1975-11-17
Abstract
No abstract record available.
Inventors
- 👤 Cameron G Harman
- 👤 Rose Ralph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:44
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/14; C09K3/1454
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
72 words
THE METHOD OF MAKING VITREOUS SILICA SUITABLE FOR USE AS A GLASS POLISHING COMPOUND COMPRISING HEATING AMORPHOUS SILICA TO A TEMPERATURE OF 1800-2200* F. FOR A TIME SUFFICIENT TO DRIVE OFF ITS WATER OF HYDRATION AND RENDER THE SILICA NON-POROUS, RAPIDLY COOLING THE HEATED SILICA AND COMMINUTING THE COOLED SILICA TO A PARTICLE SIZE SUCH THAT ABOUT 75% IS LESS THAN 5 MICRONS AND THE REMAINDER IS NO GREATER THAN 20 MICRONS.
Claim 2
Independent Claim
72 words
THE METHOD OF MAKING VITREOUS SILICA SUITABLE FOR USE AS A GLASS POLISHING COMPOUND COMPRISING HEATING AMORPHOUS SILICA TO A TEMPERATURE OF 1800-2200* F. FOR A TIME SUFFICIENT TO DRIVE OFF ITS WATER OF HYDRATION AND RENDER THE SILICA NON-POROUS, RAPIDLY COOLING THE HEATED SILICA AND COMMINUTING THE COOLED SILICA TO A PARTICLE SIZE SUCH THAT ABOUT 75% IS LESS THAN 5 MICRONS AND THE REMAINDER IS NO GREATER THAN 20 MICRONS.
Claim 3
Independent Claim
43 words
THE METHOD OF MAKING A GLASS POLISHING POWDER WHICH COMPRISES HEATING AMORPHOUS SILICA TO A TEMPERATURE OF 1800-2200* F. FOR ABOUT ONE HOUR, THEREBY RENDERING THE SILICA VITREOUS, COOLING SAID SILICA, AND COMMINUTING SAID COOLED MATERIAL TO A PARTICLE SIZE BELOW 20 MICRONS.
Claim 4
Independent Claim
43 words
THE METHOD OF MAKING A GLASS POLISHING POWDER WHICH COMPRISES HEATING AMORPHOUS SILICA TO A TEMPERATURE OF 1800-2200* F. FOR ABOUT ONE HOUR, THEREBY RENDERING THE SILICA VITREOUS, COOLING SAID SILICA, AND COMMINUTING SAID COOLED MATERIAL TO A PARTICLE SIZE BELOW 20 MICRONS.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-02-28 | 1964-08-29 | 1965-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-02-28 | 1968-08-29 | 1969-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-02-28 | 1972-08-29 | 1973-02-28 | $7700.00 | Window Closed / Lapsed |