US4255398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Novel ettringite whiskers, production and uses
Assignee: Hyogo Prefectural Government
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Filing: 1979-06-26
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Granted: 1981-03-10
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Expires: 1999-06-26
Abstract
Abstract This disclosure deals with ettringite whiskers, methods of synthesizing such whiskers and ettringite whisker composites. The ettringite whiskers, having a new crystal form, are 1-2 mu m in diameter, 50-100 mu m in length and approximately 30-50 of aspect ratio. The ettringite whiskers are especially useful in industry as a high tensile strength reinforcement, they increase self-extinguishability and the productive capacity of making sheets, boards of the like.
Inventors
- 👤 Minoru Tanaka
- 👤 Genzo Hashizume
- 👤 Hiroshi Matsui
- 👤 Satoru Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:38
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/46; C01F11/464; C04; C04B; C04B14/00; C04B14/38; C04B28/00; C04B28/02; C04B28/06; C04B28/065; C04B7/00; C08; C08K; C08K3/00; C08K3/30; D; D21; D21H; D21H13/00; D21H13/36; D21H5/00; D21H5/12; D21H5/18; C01P; C01P2004/00; C01P2004/01; C08K2201/00; C08K2201/016
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
171 words
A method of synthesizing ettringite crystal whiskers which comprises: preparing a slurry by mixing together at least 10 parts by weight of water to one part by weight of a starting material mixture comprising a. lime as a CaO component b. aluminous material as a Al 2 O 3 component c. a CaSO 4 precursor supplying component selected from the group consisting of calcium sulphite, and a mixture of gypsum and calcium sulphite with the ingredients in said starting material being adjusted so that the mole ratio of CaO, and said CaSO 4 component in said slurry is 1.3 to 4.5:1:2.3 to 4.3, effecting oxidation by blowing air into, and thereby agitating, the slurry at a temperature between about 0° C. to 100° C., and a blowing air pressure of 2 to 4 Kg/cm 2 , and filtering the thus oxidized slurry to separate ettringite crystal whiskers having a diameter of 1 to 2 μm, a length of 50 to 100 μm and an aspect ratio of about 30 to 50.
Claim 2
Independent Claim
171 words
A method of synthesizing ettringite crystal whiskers which comprises: preparing a slurry by mixing together at least 10 parts by weight of water to one part by weight of a starting material mixture comprising a. lime as a CaO component b. aluminous material as a Al 2 O 3 component c. a CaSO 4 precursor supplying component selected from the group consisting of calcium sulphite, and a mixture of gypsum and calcium sulphite with the ingredients in said starting material being adjusted so that the mole ratio of CaO, and said CaSO 4 component in said slurry is 1.3 to 4.5:1:2.3 to 4.3, effecting oxidation by blowing air into, and thereby agitating, the slurry at a temperature between about 0° C. to 100° C., and a blowing air pressure of 2 to 4 Kg/cm 2 , and filtering the thus oxidized slurry to separate ettringite crystal whiskers having a diameter of 1 to 2 μm, a length of 50 to 100 μm and an aspect ratio of about 30 to 50.
Claim 3
Dependent Claim
43 words
A method of synthesizing ettringite crystal whiskers according to claim 1, wherein a metal salt which accelerates the oxidation and crystal growth is included in the slurry in an amount of about 0.1 to 1.0% by weight based on the starting material mixture.
Claim 4
Dependent Claim
14 words
A method according to claim 2 in which the metal salt is nickel sulfate.
Claim 5
Dependent Claim
14 words
A method according to claim 2 in which the metal salt is iron sulfate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |