US3798018A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glass manufacture
Assignee: PPG Industries Inc
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Filing: 1971-12-23
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Granted: 1974-03-19
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Expires: 1991-12-23
Abstract
Abstract A process for preparing glass free of voids and imperfections is provided comprising charging an aqueous slurry of glass-forming metal hydroxide, and sand to a molten glass pool at a rate sufficient to minimize spattering, segregation of reactants and carry-off of alkali with the evolved steam, maintaining the temperature of the molten glass at or above the fusion temperature of the reactants for a time sufficient to effect reaction, and recovering the resulting glass.
Inventors
- 👤 L Paridon
- 👤 C Dye
- 👤 F Yarsa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:39
CPC Classifications
C; C03; C03B; C03B1/00; C03B3/00; C03C; C03C1/00; C03C1/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
A process for preparing glass which comprises charging a free-flowing slurry of glass-forming reactants of metal hydroxide selected from the group consisting of sodium hydroxide, potassium, hydroxide, lead hydroxide, aluminum hydroxide and calcium hydroxide and sand to a molten glass pool at a rate sufficient to minimize spattering, segregation of reactants and carry-off of metal hydroxide with the evolved steam, the metal hydroxide constituting from between about 70 and 100 percent of the alkali requirements of the glass, said slurry having a water content of at least about 15 percent by weight, and maintaining the temperature of the molten glass at or above the fusion temperature of the reactants for a time sufficient to effect reaction of the reactants metal hydroxide and sand and recovering the resultant glass.
Claim 2
Dependent Claim
130 words
A process for preparing a metal silicate which comprises charging a free-flowing slurry of metal silicate-forming reactants of metal hydroxide selected from the group consisting of sodium hydroxide, potassium hydroxide, lead hydroxide, aluminum hydroxide and calcium hydroxide and sand to a molten metal silicate pool in a furnace, at a rate such that the metal silicate-forming ingredients move along into and through the furnace without the need for mechanical agitation means, the metal hydroxide constituting from between about 70 and 100 percent of the alkali requirements of the metal silicate, said slurry having a total water content of between about 10 and about 30 weight percent, and maintaining the temperature of the molten pool for a time such that metal silicate is withdrawn substantially free of imperfections and unreacted sand.
Claim 3
Dependent Claim
12 words
The process of claim 2 wherein the metal hydroxide is sodium hydroxide.
Claim 4
Dependent Claim
30 words
The process of claim 2 wherein the metal hydroxide is sodium hydroxide havIng a water content of between about 5 and about 50 percent by weight of the glass-forming ingredients.
Claim 5
Dependent Claim
31 words
The process of claim 2 wherein the metal hydroxide and sand are proportioned to provide a SiO2/M2O mole ratio of between about 1 and about 4, wherein M is a metal.
Claim 6
Dependent Claim
21 words
The process of claim 2 wherein the temperature of the molten glass is maintained above the fusion temperature of the reactants.
Claim 7
Dependent Claim
21 words
The process of claim 2 wherein the depth of the molten glass is from between about 1 and about 6 feet.
Claim 8
Dependent Claim
25 words
The process of claim 2 wherein the metal hydroxide constitutes at least about 90 percent by weight of the total alkali requirements of the glass.
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |