Patent US3945816A successfully refreshed from Google Patents.
US3945816A
Expired / Lapsed
US
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Method for forming a refractory cellular product
Assignee: Environmental Control Products Inc
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Filing: 1974-06-05
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Granted: 1976-03-23
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Expires: 1994-06-05
Abstract
Abstract A lightweight refractory foam primarily of silica can be formed from a phase-separable silicate glass such as borosilicate glass, by melting the glass, foaming the glass at elevated temperatures, phase-separating the silicate foam glass at elevated temperatures to form a silica-rich phase and a silica-poor phase and leaching said phase-separated foam glass with warm water or dilute acids to remove substantially the silica-poor phase. The resulting refractory foam consists essentially of a silica network. The density of the refractory cellular product may be from about 0.075 grams per cubic centimeter to 0.5 grams per cubic centimeter, or higher, as desired. The refractory cellular product has a very low coefficient of expansion and high chemical durability.
Inventors
- 👤 Jerry Dean Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:16
CPC Classifications
C; C03; C03C; C03C11/00; C03C11/005; C03C15/00; C04; C04B; C04B35/00; C04B35/01; C04B35/14
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
99 words
A method of forming a lightweight refractory foam substantially of silica comprising: a. mechanically foaming a molten phase-separable alkali metal borosilicate glass having a borate content which separates into a silica-poor, borate-rich phase, b. maintaining the temperature of the foamed glass between about 450°C and about 755°C to separate said glass into a silica-rich phase and a silica-poor, borate-rich, leachable phase, c. cooling said glass below 450°C, and d. leaching said foamed, phase-separated glass with an aqueous medium for a period sufficient to remove substantially all of said borate-rich phase to yield a lightweight refractory foam substantially of silica.
Claim 2
Independent Claim
99 words
A method of forming a lightweight refractory foam substantially of silica comprising: a. mechanically foaming a molten phase-separable alkali metal borosilicate glass having a borate content which separates into a silica-poor, borate-rich phase, b. maintaining the temperature of the foamed glass between about 450°C and about 755°C to separate said glass into a silica-rich phase and a silica-poor, borate-rich, leachable phase, c. cooling said glass below 450°C, and d. leaching said foamed, phase-separated glass with an aqueous medium for a period sufficient to remove substantially all of said borate-rich phase to yield a lightweight refractory foam substantially of silica.
Claim 3
Independent Claim
123 words
A method of forming a lightweight refractory foam substantially of silica comprising: a. chemically foaming a molten phase-separable alkali metal borosilicate glass having a borate content which separates into a silica-poor, borate-rich phase by heating a mixture of said alkali metal borosilicate glass and a chemical foaming agent in a cavity until a cellular glass is produced, b. maintaining the temperature of the foamed glass between about 450° and about 755°C to separate said glass into a silica-rich phase and a silica-poor, borate-rich, leachable phase, c. cooling said glass below 450°C, and d. leaching said foamed, phase-separated glass with an aqueous medium for a period sufficient to remove substantially all of said borate-rich phase to yield a lightweight refractory foam substantially of silica.
Claim 4
Independent Claim
123 words
A method of forming a lightweight refractory foam substantially of silica comprising: a. chemically foaming a molten phase-separable alkali metal borosilicate glass having a borate content which separates into a silica-poor, borate-rich phase by heating a mixture of said alkali metal borosilicate glass and a chemical foaming agent in a cavity until a cellular glass is produced, b. maintaining the temperature of the foamed glass between about 450° and about 755°C to separate said glass into a silica-rich phase and a silica-poor, borate-rich, leachable phase, c. cooling said glass below 450°C, and d. leaching said foamed, phase-separated glass with an aqueous medium for a period sufficient to remove substantially all of said borate-rich phase to yield a lightweight refractory foam substantially of silica.
Claim 5
Dependent Claim
14 words
The method of claim 2 wherein the glass additionally contains an alkaline earth oxide.
Claim 6
Dependent Claim
45 words
A process of claim 2 wherein the phase-separable alkali metal borosilicate glass comprises less than about 20 percent by weight alkali metal oxide, about 10 percent to about 50 percent by weight boric acid and about 40 percent to about 85 percent by weight silica.
Claim 7
Dependent Claim
12 words
The process of claim 4 wherein the alkali metal oxide is soda.
Claim 8
Dependent Claim
17 words
The process of claim 4 wherein the alkali metal oxide is a mixture of alkali metal oxides.
Claim 9
Dependent Claim
23 words
A method of claim 2 wherein the alkali metal borosilicate glass is a mixture of finely ground glass and a chemical foaming agent.
Claim 10
Dependent Claim
30 words
The method of claim 2 wherein said chemical foaming agent is selected from the class consisting of calcium carbonate, strontium carbonate, barium carbonate, calcium sulfate, barium sulfate and strontium sulfate.
Claim 11
Dependent Claim
25 words
The method of claim 2 wherein foaming of said glass occurs by heating of said glass to a temperature of about 650°C to about 850°C.
Claim 12
Dependent Claim
31 words
The method of claim 2 wherein phase separating occurs by maintaining the temperature of said glass between about 450°C and 755°C for a period of about 1/2 to about 5 hours.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |