US3948629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydration of silicate glasses in aqueous solutions
Assignee: Corning Glass Works
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Filing: 1974-04-29
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Granted: 1976-04-06
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Expires: 1994-04-29
Abstract
Abstract The present invention relates to a method for hydrating fine-dimensioned alkali metal-containing silicate glass bodies so as to impart the property of thermoplasticity thereto. More particularly, this invention contemplates contacting fine-dimensioned alkali metal silicate glass bodies with an aqueous solution at elevated temperatures and pressures to develop at least a surface layer thereon having a water content ranging up to about 36% by weight, said aqueous solution having a pH less than 6 as measured at room temperature. The hydrated bodies can approach certain properties of high-polymer organic plastics and exhibit the capability of being thermoplastically formed at relatively low temperatures.
Inventors
- 👤 Roger F. Bartholomew
- 👤 Larry E. Campbell
- 👤 Stanley S. Lewek
- 👤 Joseph E. Pierson
- 👤 Stanley D. Stookey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:16
CPC Classifications
C; C03; C03C; C03C23/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
120 words
A method for making a hydrated glass body exhibiting thermoplastic properties which comprises contacting a fine-dimensioned anhydrous glass body consisting essentially, in mole percent on the oxide basis, of about 3-25% Na 2 O and/or K 2 O and 50-95% SiO 2 , the sum of those components constituting at least 55% of the total composition, with an aqueous solution environment having a pH less than 6, as measured at room temperature, this contact being made at a temperature in excess of 100°C. and at a pressure in excess of 20 psig for a period of time sufficient to hydrate at least a surface portion having an amount of H 2 O absorbed therein effective to impart thermoplastic properties thereto.
Claim 2
Independent Claim
120 words
A method for making a hydrated glass body exhibiting thermoplastic properties which comprises contacting a fine-dimensioned anhydrous glass body consisting essentially, in mole percent on the oxide basis, of about 3-25% Na 2 O and/or K 2 O and 50-95% SiO 2 , the sum of those components constituting at least 55% of the total composition, with an aqueous solution environment having a pH less than 6, as measured at room temperature, this contact being made at a temperature in excess of 100°C. and at a pressure in excess of 20 psig for a period of time sufficient to hydrate at least a surface portion having an amount of H 2 O absorbed therein effective to impart thermoplastic properties thereto.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein said temperature ranges up to about 374°C.
Claim 4
Dependent Claim
13 words
A method according to claim 1 wherein said temperature ranges between about 200°-300°C.
Claim 5
Dependent Claim
15 words
A method according to claim 1 wherein said pressure ranges up to about 3200 psi.
Claim 6
Dependent Claim
22 words
A method accordng to claim 1 wherein said aqueous solution is buffered to maintain the pH below 6 during the hydration process.
Claim 7
Dependent Claim
16 words
A method according to claim 1 wherein said aqueous solution has a pH less than 5.
Claim 8
Dependent Claim
20 words
A method according to claim 4 wherein said hydrated glass body exhibits greater chemical durability than the anhydrous glass body.
Claim 9
Dependent Claim
21 words
A method according to claim 1 wherein said fine-dimensioned glass body has a thickness dimension no greater than about 5 mm.
Claim 10
Dependent Claim
16 words
A method according to claim 1 wherein said aqueous solution contains an acid and/or a salt.
Claim 11
Dependent Claim
21 words
A method according to claim 9 wherein said aqueous solution contains said acid and/or salt in an amount up to saturation.
Claim 12
Dependent Claim
17 words
A method according to claim 1 wherein said amount of water absorbed ranges up to about 36%.
Claim 13
Dependent Claim
14 words
A method according to claim 1 wherein said time ranges between about 2-48 hours.
Claim 14
Dependent Claim
61 words
A method for forming shapes from the fine-dimensioned glass bodies made in accordance with claim 1 exhibiting thermoplastic properties which comprises the steps of: a. forming a mass of said bodies to a shape of a desired configuration under pressure and at a temperature ranging from about room temperature to about 500°C.; and, thereafter, b. bringing said shape to room temperature.
Claim 15
Dependent Claim
19 words
A method according to claim 9 wherein said mass of bodies is formed at a temperature between about 100°-400°C.
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) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |