Patent US3801339A successfully refreshed from Google Patents.
US3801339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expansive additive for lime cement and process for the preparation of the same
Assignee: Denka Co Ltd
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Filing: 1971-08-06
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Granted: 1974-04-02
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Expires: 1991-08-06
Abstract
Abstract An expansive additive composition for use in controlling the expansion of cement on aging comprising a sintered mixture of lime and at least one additive selected from the group consisting of ferric oxide, calcium fluoride and calcium sulfate is disclosed. The process for preparing the expansive additive composition is also disclosed.
Inventors
- 👤 Y Ono
- 👤 Y Taketsume
- 👤 H Ogura
- 👤 T Takizawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:46
CPC Classifications
C; C04; C04B; C04B22/00; C04B22/008
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
38 words
The cement composition of claim 1, wherein said additive is ferric oxide and said ferric oxide is present at a level of from 3 to 40 percent by weight based on the weight of the crushed sintered mixture.
Claim 2
Dependent Claim
37 words
The cement composition of claim 1, wherein said additive is calcium fluoride and said calcium fluoride is present at a level of from 3 to 60% by weight based on the weight of the crushed sintered mixture.
Claim 3
Dependent Claim
37 words
The cement composition of claim 1, wherein said additive is calcium sulfate and said calcium sulfate is present at a level of from 30 to 85% by weight based on the weight of the crushed sintered mixture.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |