US4268310A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dental compositions of improved properties
Assignee: OCCIDENTIAL ELECTROCHEMICALS Corp
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Filing: 1980-04-28
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Granted: 1981-05-19
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Expires: 2000-04-28
Abstract
Abstract A dental gypsum composition having good pourable consistency and controlled mixing and setting characteristics comprising a mixture of calcium sulfate hemihydrate (calcined gypsum), a condensation product of formaldehyde with a cyclic hydrocarbon containing sulfonic acid groups, and magnesium aluminum silicate. When dispersed in water and cured, this composition provides set products having improved hardness and strength properties.
Inventors
- 👤 William R. Nemeth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:14
CPC Classifications
A; A61; A61K; A61K6/00; A61K6/80; A61K6/849; A61K6/858; Y; Y10; Y10S; Y10S528/00; Y10S528/92
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
39 words
A dental composition consisting essentially of calcined gypsum, magnesium aluminum silicate, and a surfactant selected from the group consisting of a condensation product of formaldehyde and naphthalene sulfonic acid and a condensation product of formaldehyde and melamine sulfonic acid.
Claim 2
Dependent Claim
39 words
A dental composition consisting essentially of calcined gypsum, magnesium aluminum silicate, and a surfactant selected from the group consisting of a condensation product of formaldehyde and naphthalene sulfonic acid and a condensation product of formaldehyde and melamine sulfonic acid.
Claim 3
Dependent Claim
15 words
The dental composition of claim 1 wherein the calcined gypsum is alpha calcium sulfate hemihydrate.
Claim 4
Dependent Claim
15 words
The dental composition of claim 1 wherein the calcined gypsum is beta calcium sulfate hemihydrate.
Claim 5
Dependent Claim
19 words
The dental composition of claim 1 wherein the surfactant is a condensation product of formaldehyde and naphthalene sulfonic acid.
Claim 6
Dependent Claim
19 words
The dental composition of claim 1 wherein the surfactant is a condensation product of formaldehyde and melamine sulfonic acid.
Claim 7
Dependent Claim
31 words
The dental composition of claim 1 which contains from about 0.10 to 0.25 percent, by weight, of magnesium aluminum silicate and from about 0.20 to 1.0 percent, by weight, of surfactant.
Claim 8
Dependent Claim
31 words
The dental composition of claim 6 which contains from about 0.15 to 0.20 percent, by weight, of magnesium aluminum silicate and from about 0.4 to 0.8 percent, by weight, of surfactant.
Claim 9
Independent Claim
77 words
A method of reducing the amount of water required to be mixed with a dental powder to obtain a pourable slurry which comprises adding to a calcined gypsum from about 0.10 to 0.25 percent, by weight, of magnesium aluminum silicate and from about 0.20 to 1.0 percent, by weight, of a surfactant selected from the group consisting of a condensation product of formaldehyde and naphthalene sulfonic acid and a condensation product of formaldehyde and melamine sulfonic acid.
Claim 10
Independent Claim
77 words
A method of reducing the amount of water required to be mixed with a dental powder to obtain a pourable slurry which comprises adding to a calcined gypsum from about 0.10 to 0.25 percent, by weight, of magnesium aluminum silicate and from about 0.20 to 1.0 percent, by weight, of a surfactant selected from the group consisting of a condensation product of formaldehyde and naphthalene sulfonic acid and a condensation product of formaldehyde and melamine sulfonic acid.
Claim 11
Dependent Claim
17 words
The method of claim 8 wherein the magnesium aluminum silicate and surfactant are added to the gypsum.
Claim 12
Dependent Claim
33 words
The method of claim 8 wherein the magnesium aluminum silicate and surfactant are incorporated into the volume of water to be used to slurry the gypsum prior to its admixture with said gypsum.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-18 | 1984-11-17 | 1985-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-18 | 1988-11-17 | 1989-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-18 | 1992-11-17 | 1993-05-19 | $7700.00 | Window Closed / Lapsed |