US4144121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing asbestos-free calcium silicate board and the board produced thereby
Assignee: Nichias Corp
•
Filing: 1977-05-03
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Granted: 1979-03-13
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Expires: 1997-05-03
Abstract
Abstract This invention relates to a method for making an asbestos-free calcium silicate board, which comprises preparing a slurry of a mixture of silicic acid material, lime material, fibrous wollastonite and pulp with a large amount of water, forming the slurry into a raw board by means of the sheet-forming technique, steaming the raw board and drying. This invention also relates to the board produced in accordance with the above method.
Inventors
- 👤 Takashi Otouma
- 👤 Hiroshi Asaumi
- 👤 Kazuo Kubota
- 👤 Mitsuo Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:53
CPC Classifications
D; D21; D21J; D21J1/00; D21J1/16
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
92 words
A method for making an asbestos-free calcium silicate board, which comprises (a) preparing a slurry of a mixture of 20-50% of silicic acid material, 20-50% of lime material, 10-40% of fibrous wollastonite, 2-10% of pulp selected from the group consisting of N-BKP, N-UKP, flax pulp and waste paper and 1-30% of calcium silicate crystals prepared by hydrothermal synthesis, with water; (b) forming the slurry into a raw board; (c) steaming the raw board; and then (d) drying, all of the said percentages being based on the weight of the total solids content.
Claim 2
Independent Claim
92 words
A method for making an asbestos-free calcium silicate board, which comprises (a) preparing a slurry of a mixture of 20-50% of silicic acid material, 20-50% of lime material, 10-40% of fibrous wollastonite, 2-10% of pulp selected from the group consisting of N-BKP, N-UKP, flax pulp and waste paper and 1-30% of calcium silicate crystals prepared by hydrothermal synthesis, with water; (b) forming the slurry into a raw board; (c) steaming the raw board; and then (d) drying, all of the said percentages being based on the weight of the total solids content.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the water is employed in an amount of about 10 times the total solids content.
Claim 4
Dependent Claim
16 words
An asbestos-free calcium silicate board prepared in accordance with the method as claimed in claim 1.
References Cited (Backward Citations)
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US2309206A
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US2888377A
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US3219467A
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-12 | 1982-09-11 | 1983-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-12 | 1986-09-11 | 1987-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-12 | 1990-09-11 | 1991-03-13 | $7700.00 | Window Closed / Lapsed |