US4153505A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sorbent materials
Assignee: 3M Co
•
Filing: 1975-05-09
•
Granted: 1979-05-08
•
Expires: 1995-05-09
Abstract
Abstract A composite sorptive material in the form of a self-supporting, fluid-permeable sheet of fibrous material having distributed throughout a powdered sorbent material. The sheets provide a simple and convenient way of handling and using powdered sorbent materials. Suitable powdered sorbent materials include activated charcoal and powdered sorbent foam which has been prepared by the pyrolysis of an aromatic nitrogen-containing compound.
Inventors
- 👤 Alan N. Ferguson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:11
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/28; B01J20/28014; B01J20/28033; B01J20/22; B01J20/28002; B01J20/28004; B01J20/28028; B01J20/2803; B01J20/28054; B01J20/28057; C; C23; C23F; C23F15/00; D; D21; D21H; D21H21/00; D21H21/14; D21H21/22; D21H21/50; D21H21/56; Y; Y10; Y10S; Y10S55/00; Y10S55/13
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
164 words
A composite sorbtive material comprising a self-supporting, fluid permeable sheet of fibrous material in which a powdered sorbent black thermoset foam has been distributed throughout the sheet and retained in the sheet by the fibrous material, said foam having been prepared by the pyrolysis of a composition liquid at the pyrolysis temperature comprising at least one aromatic nitrogen-containing compound having the general formula: X--Ar--Y in which Ar represents an aromatic nucleus, X represents a substituent having a negative Hammett sigma constant and attached by a nitrogen, oxygen or sulphur atom, and Y represents a substituent having a positive Hammett sigma constant and attached by a nitrogen atom, the substituents X and/or Y forming part of a ring fused onto the aromatic nucleus or attached directly to the aromatic nucleus, the thermoset foam having a specific surface area of at least 50 m 2 /g, and said pyrolysis comprising heating said composition to a temperature below 300° C. to initiate reaction of the said composition.
Claim 2
Dependent Claim
164 words
A composite sorbtive material comprising a self-supporting, fluid permeable sheet of fibrous material in which a powdered sorbent black thermoset foam has been distributed throughout the sheet and retained in the sheet by the fibrous material, said foam having been prepared by the pyrolysis of a composition liquid at the pyrolysis temperature comprising at least one aromatic nitrogen-containing compound having the general formula: X--Ar--Y in which Ar represents an aromatic nucleus, X represents a substituent having a negative Hammett sigma constant and attached by a nitrogen, oxygen or sulphur atom, and Y represents a substituent having a positive Hammett sigma constant and attached by a nitrogen atom, the substituents X and/or Y forming part of a ring fused onto the aromatic nucleus or attached directly to the aromatic nucleus, the thermoset foam having a specific surface area of at least 50 m 2 /g, and said pyrolysis comprising heating said composition to a temperature below 300° C. to initiate reaction of the said composition.
Claim 3
Dependent Claim
65 words
A material as claimed in claim 1 in which the sorbtive material has been made by allowing a liquid mixture of at least one aromatic amine and sufficient concentrated nitric acid to react at elevated temperatures to give initially the evolution of nitrogen oxides followed by a pyrolysis reaction to give an expanded solid which is black sorbent cross-linked thermoset foam insoluble in organic solvents.
Claim 4
Dependent Claim
32 words
A material as claimed in claim 1 in which the foam is in the form of a fine powder whose particles range from 0.5 micrometers in diameter to 0.5 millimeters in diameter.
Claim 5
Dependent Claim
23 words
A material as claimed in claim 1 in which the relative proportions of powder to fibers is from 1 to 50% by weight
Claim 6
Dependent Claim
17 words
A material as claimed in claim 1 in which the sheet is a water-laid sheet of fibers.
Claim 7
Dependent Claim
18 words
A material as claimed in claim 5 in which the fibers are cellulose fibers of paper making length.
Claim 8
Dependent Claim
41 words
The composite material of claim 1 wherein said foam was prepared with at least one Lewis acid metal salt in combination with said aromatic nitrogen-containing compound, and the Lewis acid metallic salt was removed from the material resulting from said pyrolysis.
References Cited (Backward Citations)
US3246767A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-07 | 1982-11-06 | 1983-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-07 | 1986-11-06 | 1987-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-07 | 1990-11-06 | 1991-05-08 | $7700.00 | Window Closed / Lapsed |