US3791809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of strengthening glass articles using powdered salts for ion exchange
Assignee: OI Glass Inc
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Filing: 1973-01-12
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Granted: 1974-02-12
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Expires: 1993-01-12
Abstract
Abstract Methods for strengthening glass articles such as glass containers are disclosed using powdered salts as the ion exchange medium. In one embodiment, beer bottles made of a conventional flint container glass are sprayed with a powdered ion exchange medium comprising potassium nitrate and tripotassium phosphate. The hot, newly-formed bottles can be advantageously run through the normal annealing treatment in a large volume production line to provide strengthened bottles.
Inventors
- 👤 R Lau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:25
CPC Classifications
C; C03; C03C; C03C21/00; C03C21/008
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
32 words
The method of claim 1, wherein the glass composition includes at least 2% by weight of soda (Na2O) and wherein the admixture of alkali metal salts contains at least one potassium salt.
Claim 2
Dependent Claim
59 words
heating the layer of powdered material as the bottle passes through the annealing station to provide a strengthened bottle by ion exchange of alkali metal ions in the layer of partially fused, powdered material for the sodium ions in the surface layer of the glass bottle to provide a compressive stress layer on the bottle and strengthen the same.
Claim 3
Dependent Claim
19 words
The method of claim 2 wherein the potassium salt layer is removed by washing the glass article with water.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the alkali metal salt admixture comprises K3PO4 and KNO3.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein the alkali metal salt admixture comprises KNO3 and K2HPO4.
Claim 6
Dependent Claim
43 words
The method of claim 1 wherein said elevated temperature is at least about 200* C. and less than about 50* C. above the annealing point of the glass being treated for a time period ranging from about 5 minutes to about 24 hours.
Claim 7
Dependent Claim
18 words
The method of claim 1 wherein the glass composition contains at least about 5% by weight of soda.
Claim 8
Dependent Claim
20 words
The method of claim 1 wherein said powdered admixture contains an organic material which assists the flowability of the coating.
Claim 9
Dependent Claim
50 words
The method of claim 1 wherein said coating layer is formed on the glass article by spraying the powdered admixture onto said article immediately after forming said article, and the elevated temperature necessary for the ion exchange reaction is provided by the subsequent annealing heat treatment of the glass article.
Claim 10
Dependent Claim
12 words
The method of clAim 1 wherein said glass is a soda-lime-silica glass.
Claim 11
Dependent Claim
12 words
The method of claim 1 wherein said glass is an aluminosilicate glass.
Claim 12
Dependent Claim
12 words
A strengthened silicate glass article made by the method of claim 1.
Claim 13
Dependent Claim
100 words
In a process of making bottles of container glass, containing sodium ions, expressed as sodium oxide, by forming a bottle from a quantity of molten glass at a forming station, transferring the newly-formed bottle to an annealing station at a temperature at or above the strain point of the glass but below the softening point, moving the bottles through the annealing station to remove stresses created in the glass by the bottle-forming operation, and cooling the bottle from the annealing station to a moderate elevated temperature that is substantially below the strain point of the glass, the improvement which comprises:
Claim 14
Dependent Claim
16 words
A process as defined in claim 13 in which the glass is a flint container glass.
Claim 15
Dependent Claim
57 words
A process as defined in claim 13 in which the mixture of powdered alkali metal salts comprises a first alkali salt of relatively low melting point and a second alkali metal salt having a melting point higher than that of the first salt whereby the second salt adheres to the fused layer formed by the first layer.
Claim 16
Dependent Claim
19 words
A process as defined in claim 15 in which the mixture of alkali metal salts comprises KNO3 and K2HPO4.
Claim 17
Dependent Claim
19 words
A process as defined in claim 15 in which the mixture of alkali metal salts comprises KNO3 and K3PO4.
Claim 18
Dependent Claim
10 words
A strengthed bottle made by the process of claim 13.
Claim 19
Dependent Claim
21 words
A process as defined in claim 13 in which the glass composition comprises at least about 5% by weight of soda.
Claim 20
Dependent Claim
28 words
A process as defined in claim 13 in which the glass composition comprises: Ingredient Parts By Weight SiO2 72 Al2O3 1.9 CaO9.6 MgO 4.2 Na2O 11.5 K2O 0.4
Claim 21
Dependent Claim
24 words
A process as defined in claim 13 in which the mixture of alkali metal salts contains at least about 25% by weight of KNO3.
Claim 22
Dependent Claim
35 words
A process as defined in claim 13 in which the mixture of alkali metal salts contains about 25 to 50 parts by weight of KNO3 and about 50 to 90 parts by weight of K2HPO4.
Claim 23
Dependent Claim
45 words
A process as defined in claim 13 in which the mixture of alkali metal salts comprises about 25 to 50 parts by weight of KNO3, and about 50-90 parts by weight of K3PO4 and about 1/2 to 10 parts by weight of a lubricious filler.
Claim 24
Dependent Claim
38 words
A process as defined in claim 13 in which the mixture of alkali metal salts includes about 43 parts by weight of KNO3, about 55 parts by weight of K3PO4 and about 2 parts by weight of cornstarch.
Claim 25
Dependent Claim
54 words
A process as defined in claim 13 in which the mixture of alkali metal salts comprises about 30 to 45 parts by weight of KNO3, about 55 to 85 parts by weight of K2 HPO4, and about 1 to 4 parts by weight of a lubricious filler for enhancing the flowability of the mixture.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |