US4529623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Activated carbon products and their manufacture
Assignee: Charcoal Cloth Ltd
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Filing: 1983-09-13
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Granted: 1985-07-16
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Expires: 2003-09-13
Abstract
Abstract An activated carbon product such as a charcoal cloth or felt has, in addition to any activating material, a metal uniformly dispersed therein. The metal may be catalytic or bactericidal, and a particularly preferred product of the invention contains silver and is suitable for use as a surgical dressing. Such products can be produced by a conventional activation procedure using a mixture of halides, even if the further metal halide is substantially insoluble in the impregnation solution used for activation, by incorporating in the solution ammonia and a sequestering agent such as citric acid.
Inventors
- 👤 Frederick A. P. Maggs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:30
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/46; A61F; A61F13/00; A61L15/18; C; C01; C01B; C01B32/00; C01B32/30; C01B32/354; C01B32/382; A61F2013/00361; A61F2013/00902; A61F2013/00936; A61L2300/00; A61L2300/10; A61L2300/102; A61L2300/104; A61L2300/108; A61L2300/40; A61L2300/404; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/30; Y10T442/00; Y10T442/30; Y10T442/3382; Y10T442/40; Y10T442/475; Y10T442/50; Y10T442/57; Y10T442/60; Y10T442/654; Y10T442/658
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
77 words
A process for the preparation of an activated charcoal cloth or felt which comprises treating a fibrous carbohydrate material with a solution of at least one Lewis acid halide selected from the halides of Zn, Al, Ca, Mg and Fe; a compound of a second metal element whose halide is relatively insoluble with respect to the, or the mixture of, Lewis acid halides; ammonia; and a sequestering agent; and then drying, carbonising and activating the carbohydrate material.
Claim 2
Dependent Claim
77 words
A process for the preparation of an activated charcoal cloth or felt which comprises treating a fibrous carbohydrate material with a solution of at least one Lewis acid halide selected from the halides of Zn, Al, Ca, Mg and Fe; a compound of a second metal element whose halide is relatively insoluble with respect to the, or the mixture of, Lewis acid halides; ammonia; and a sequestering agent; and then drying, carbonising and activating the carbohydrate material.
Claim 3
Dependent Claim
14 words
A process according to claim 1, in which the second metal element is silver.
Claim 4
Dependent Claim
15 words
A process according to claim 1, in which the sequestering agent is a hydroxycarboxylic acid.
Claim 5
Dependent Claim
14 words
A process according to claim 3, in which the hydroxycarboxylic acid is citric acid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-15 | 1989-01-14 | 1989-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-15 | 1993-01-14 | 1993-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-15 | 1997-01-14 | 1997-07-16 | $7700.00 | Window Closed / Lapsed |