US4059456A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition for accelerating the setting of calcined gypsum and the product formed thereby
Assignee: United States Gypsum Co
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Filing: 1975-10-21
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Granted: 1977-11-22
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Expires: 1995-10-21
Abstract
Abstract A composition for accelerating the setting of an aqueous calcined gypsum slurry, the composition comprising finely ground calcium sulfate dihydrate and a lignosulfonate. The composition, when added to an aqueous calcined gypsum slurry, accelerates the setting process and shortens the set time period as determined by the temperature rise set test procedure. The composition is useful for making gypsum wallboard.
Inventors
- 👤 Felix J. DeRooy
- 👤 Thell D. Daniel
- 👤 Erle C. Annes
- 👤 Billy G. Arnold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:59
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/14; C04B2103/00; C04B2103/10; C04B2103/12; C04B2103/30; C04B2103/302; C04B2111/00; C04B2111/00474; C04B2111/00612; C04B2111/0062
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
44 words
A dry composition for accelerating the setting reaction of an aqueous slurry of calcium sulfate hemihydrate, comprising finely ground calcium sulfate dihydrate and a lignosulfonate, said lignosulfonate being present in an amount of from about 0.5 to about 99% by weight of said composition.
Claim 2
Dependent Claim
44 words
A dry composition for accelerating the setting reaction of an aqueous slurry of calcium sulfate hemihydrate, comprising finely ground calcium sulfate dihydrate and a lignosulfonate, said lignosulfonate being present in an amount of from about 0.5 to about 99% by weight of said composition.
Claim 3
Dependent Claim
18 words
A composition according to claim 1, wherein said calcium sulfate dihydrate and said lignosulfonate are finely ground together.
Claim 4
Dependent Claim
15 words
A composition according to claim 1, wherein said lignosulfonate has a wood sugar associated therewith.
Claim 5
Dependent Claim
34 words
A composition according to claim 3, wherein the particles of said composition have a surface area of from about 5,000 to about 20,000 square centimeters per gram as determined by a Fisher Sub-sieve Sizer.
Claim 6
Dependent Claim
29 words
A composition according to claim 1, wherein the total amount of said lignosulfonate and associated wood sugar is from about 3 to about 75% by weight of said composition.
Claim 7
Dependent Claim
12 words
A composition according to claim 3, wherein said lignosulfonate is ammonium lignosulfonate.
Claim 8
Dependent Claim
12 words
A composition according to claim 3, wherein said lignosulfonate is sodium lignosulfonate.
Claim 9
Dependent Claim
12 words
A composition according to claim 3, wherein said lignosulfonate is calcium lignosulfonate.
Claim 10
Dependent Claim
14 words
A composition according to claim 3, wherein said lignosulfonate is in the acid form.
Claim 11
Dependent Claim
28 words
A composition according to claim 3, wherein the amount of said lignosulfonate and associated wood sugar is from about 3 to about 75% by weight of said composition.
Claim 12
Dependent Claim
14 words
A composition according to claim 3, wherein said lignosulfonate is in the solid state.
References Cited (Backward Citations)
US2078198A
Cited
US2856304A
Cited
US2957774A
Cited
US3053673A
Cited
US3108008A
Cited
US3573947A
Cited
US3723145A
Cited
US3772045A
Cited
US3725090A
Cited
US3864141A
Cited
US3870538A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-21 | 1981-05-23 | 1981-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-21 | 1985-05-23 | 1985-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-21 | 1989-05-23 | 1989-11-22 | $7700.00 | Window Closed / Lapsed |