US4218261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Retarder for gypsum plaster and a process for retarding the setting of gypsum plaster by the use thereof
Assignee: Ajinomoto Co Inc
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Filing: 1979-05-23
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Granted: 1980-08-19
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Expires: 1999-05-23
Abstract
Abstract A retarder for gypsum plaster is provided which consists essentially of β-hydroxy-β-carboxy-isocaproic acid or a water soluble salt thereof. It has powerful retarding effect toward gypsum plaster and gives a solid product having much better mechanical strength than that encountered when an alkali metal salt of citric acid or powdered glue which are the ordinary set retarders are used. A process for retarding the setting of gypsum plaster by the use thereof, is also provided.
Inventors
- 👤 Koji Takeuchi
- 👤 Takashi Zama
- 👤 Shizuo Iwai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:50
CPC Classifications
C; C04; C04B; C04B24/00; C04B24/04; C04B24/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
23 words
A plaster composition comprising gypsum plaster and, as a retarder for retarding the setting thereof, β-hydroxy-β-carboxy-isocaproic acid or a water soluble salt thereof.
Claim 2
Dependent Claim
23 words
A plaster composition comprising gypsum plaster and, as a retarder for retarding the setting thereof, β-hydroxy-β-carboxy-isocaproic acid or a water soluble salt thereof.
Claim 3
Dependent Claim
19 words
A plaster composition according to claim 1, wherein said water soluble salt is an alkali metal or ammonium salt.
Claim 4
Dependent Claim
39 words
A plaster composition according to claim 1, wherein β-hydroxyβ-carboxy-isocaprioic acid or a water soluble salt thereof is present in an amount of from about 0.01 to about 5 parts by weight per 100 parts by weight of gypsum hemihydrate.
Claim 5
Dependent Claim
39 words
A process for retarding the setting of a gypsum plaster composition which comprises incorporating in said gypsum plaster composition an effective amount of a retarder selected from the group consisting of β-hydroxy-β-carboxy-isocaproic acid and a water soluble salt thereof.
Claim 6
Dependent Claim
39 words
A process for retarding the setting of a gypsum plaster composition which comprises incorporating in said gypsum plaster composition an effective amount of a retarder selected from the group consisting of β-hydroxy-β-carboxy-isocaproic acid and a water soluble salt thereof.
Claim 7
Dependent Claim
32 words
A process according to claim 4, wherein said retarder is incorporated in an amount of from about 0.01 to about 5 parts by weight per 100 parts by weight of gypsum hemihydrate.
References Cited (Backward Citations)
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Cited
US2607427A
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US3215549A
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US3451832A
Cited
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Cited
US3598621A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-19 | 1984-02-18 | 1984-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-19 | 1988-02-18 | 1988-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-19 | 1992-02-18 | 1992-08-19 | $7700.00 | Window Closed / Lapsed |