Patent US4222984A successfully refreshed from Google Patents.
US4222984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of wallboard manufacture
Assignee: Combustion Engineering Inc
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Filing: 1978-10-30
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Granted: 1980-09-16
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Expires: 1998-10-30
Abstract
Abstract To calcium lignin sulfonate is added a formulation of ammonium or sodium linear alcohol ether sulfate in a ratio to form an additive to calcined gypsum slurry which will reduce the water requirement and the heat needed to cure the wallboard made from the slurry.
Inventors
- 👤 Richard D. Ladwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:41
CPC Classifications
C; C04; C04B; C04B24/00; C04B24/16; C04B28/00; C04B28/14; C04B2103/00; C04B2103/40; C04B2103/408; C04B2111/00; C04B2111/00474; C04B2111/00612; C04B2111/0062
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
85 words
A process for making wallboard, including, calcining gypsum with which to form a slurry, mixing with the calcined gypsum a formulation of a calcium lignin sulfonate and ammonium linear alcohol ether sulfate, which formulation is in a ratio, whose range includes 1:1 to 3:1 by weight, adding water to form a slurry of the mixture, sandwiching the slurry in a paper envelope to form the wallboard, and heating the wallboard to drive off enough water to give the wallboard its final desired hardness and strength.
Claim 2
Dependent Claim
85 words
A process for making wallboard, including, calcining gypsum with which to form a slurry, mixing with the calcined gypsum a formulation of a calcium lignin sulfonate and ammonium linear alcohol ether sulfate, which formulation is in a ratio, whose range includes 1:1 to 3:1 by weight, adding water to form a slurry of the mixture, sandwiching the slurry in a paper envelope to form the wallboard, and heating the wallboard to drive off enough water to give the wallboard its final desired hardness and strength.
Claim 3
Dependent Claim
85 words
A process for making wallboard, including, calcining gypsum with which to form a slurry, mixing with the calcined gypsum a formulation of a calcium lignin sulfonate and sodium linear alcohol ether sulfate, which formulation is in a ratio, whose range includes 1:1 to 3:1 by weight, adding water to form a slurry of the mixture, sandwiching the slurry in a paper envelope to form the wallboard, and heating the wallboard to drive off enough water to give the wallboard its final desired hardness and strength.
Claim 4
Dependent Claim
85 words
A process for making wallboard, including, calcining gypsum with which to form a slurry, mixing with the calcined gypsum a formulation of a calcium lignin sulfonate and sodium linear alcohol ether sulfate, which formulation is in a ratio, whose range includes 1:1 to 3:1 by weight, adding water to form a slurry of the mixture, sandwiching the slurry in a paper envelope to form the wallboard, and heating the wallboard to drive off enough water to give the wallboard its final desired hardness and strength.
Claim 5
Dependent Claim
47 words
The process of claim 1 wherein, the formulation of calcium lignin sulfonate and the ammonium linear alcohol ether sulfate is added to the calcined gypsum in a ratio whose range includes 0.5 to 10.0 pounds of the formulation to one thousand square feet of one-half inch wallboard.
Claim 6
Dependent Claim
47 words
The process of claim 2 wherein, the formulation of calcium lignin sulfonate and the sodium linear alcohol ether sulfate is added to the calcined gypsum in a ratio whose range includes 0.5 to 10.0 pounds of the formulation to one thousand square feet of one-half inch wallboard.
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) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |