US4438212A
Expired / Lapsed
US
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Fluorine-free calcium-aluminosilicate glasses
Assignee: Pilkington Group Ltd
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Filing: 1982-06-28
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Granted: 1984-03-20
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Expires: 2002-06-28
Abstract
Abstract The invention relates to calciumaluminosilicate glasses. The glasses contain, in weight percent, 25 to 35% silica, 27 to 35% calcium oxide, 25 to 40% alumina, 0 to 4% of alkali metal oxide selected from lithium oxide, sodium oxide and potassium oxide, and 0 to 5% of titanium oxide and a total content of lithium, sodium, potassium and titanium oxides of 0.5 to 9%. The glasses, in finely divided form, react with aqueous polycarboxylic acids and set to a solid mass; cements made from the glass and polycarboxylic acids are useful in splinting compositions.
Inventors
- 👤 William D. Potter
- 👤 Andrew C. Barclay
- 👤 Reginald Dunning
- 👤 Richard J. Parry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:04
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/28; A; A61; A61L; A61L15/00; A61L15/07; A61L15/12; A61L24/00; A61L24/0047; A61L24/0073; A61L24/0089; C03; C03C; C03C12/00; C03C3/00; C03C3/04; C03C3/062
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
91 words
A fluorine-free calciumaluminosilicate glass consisting essentially of 25 to 35% silica, 27 to 35% calcuim oxide, 25 to 40% alumina, 0 to 4% of alkali metal oxide selected from lithium oxide, sodium oxide and potassium oxide, and 0 to 5% of titanium oxide with a total content of lithium, sodium, potassium and titanium oxides of 0.5 to 9%, and with a ratio of calcium oxide to silica of 0.7:1 to 1.0:0.7, said glass being in particulate form in which the individual particles have a particle size of less than 100 microns.
Claim 2
Dependent Claim
91 words
A fluorine-free calciumaluminosilicate glass consisting essentially of 25 to 35% silica, 27 to 35% calcuim oxide, 25 to 40% alumina, 0 to 4% of alkali metal oxide selected from lithium oxide, sodium oxide and potassium oxide, and 0 to 5% of titanium oxide with a total content of lithium, sodium, potassium and titanium oxides of 0.5 to 9%, and with a ratio of calcium oxide to silica of 0.7:1 to 1.0:0.7, said glass being in particulate form in which the individual particles have a particle size of less than 100 microns.
Claim 3
Dependent Claim
21 words
A glass as claimed in claim 1 containing in total from 1.5 to 5% of the alkali metal and titanium oxides.
Claim 4
Dependent Claim
22 words
A glass as claimed in claim 1 containing 28 to 34% silica, 28 to 34% calcium oxide and 30 to 40% alumina.
Claim 5
Dependent Claim
23 words
A glass as claimed in claim 1 which is free from sodium, potassium and lithium oxides and contains 1 to 4% titanium oxide.
Claim 6
Dependent Claim
26 words
A glass as claimed in claim 1 which is free of titanium oxide and contains 1.5 to 3% in total of sodium, potassium and lithium oxides.
Claim 7
Dependent Claim
19 words
A glass as claimed in claim 1 containing calcium oxide and silica in a ratio of 0.8:1 to 1:1.1.
Claim 8
Dependent Claim
19 words
A glass as claimed in claim 1 containing calcium oxide and silica in a ratio of 0.9:1 to 1:1.
Claim 9
Dependent Claim
29 words
A glass as claimed in claim 1 consisting essentially of 30 to 34% silica, 28 to 33% calcium oxide, 32 to 40% alumina and 1 to 3% sodium oxide.
Claim 10
Dependent Claim
67 words
A fluorine-free calciumaluminosilicate glass consisting essentially of 28 to 34% silica, 28 to 34% calcium oxide, 30 to 40% alumina and 0 to 4% of sodium oxide and 0 to 5% of titanium oxide with a total content of sodium and titanium oxides of 1.5 to 5%, said glass being in particulate form in which the individual particles have a particle size of less than 100 microns.
Claim 11
Dependent Claim
67 words
A fluorine-free calciumaluminosilicate glass consisting essentially of 28 to 34% silica, 28 to 34% calcium oxide, 30 to 40% alumina and 0 to 4% of sodium oxide and 0 to 5% of titanium oxide with a total content of sodium and titanium oxides of 1.5 to 5%, said glass being in particulate form in which the individual particles have a particle size of less than 100 microns.
Claim 12
Dependent Claim
45 words
A fluorine-free calciumaluminosilicate glass consisting essentially of 30 to 34% silica, 28 to 33% calcium oxide, 32 to 40% alumina and 1 to 3% sodium oxide, and being in particulate form in which the individual particles have a particle size of less than 100 microns.
Claim 13
Dependent Claim
45 words
A fluorine-free calciumaluminosilicate glass consisting essentially of 30 to 34% silica, 28 to 33% calcium oxide, 32 to 40% alumina and 1 to 3% sodium oxide, and being in particulate form in which the individual particles have a particle size of less than 100 microns.
References Cited (Backward Citations)
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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) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |