US3661503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for dehydrating cellulosic textile material
Assignee: BP Corp North America Inc
•
Filing: 1969-05-29
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Granted: 1972-05-09
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Expires: 1989-05-29
Abstract
Abstract Flexible carbonaceous textile materials are produced by treating a cellulosic textile material with phosphoric acid, heating the acid-treated material at a temperature between 100* C. and 350* C. in an ammonia-containing atmosphere to produce a nonflammable, non-fusible, strong and flexible permanently dehydrated material, and carbonizing or graphitizing the product so produced to obtain the desired flexible carbonaceous textile material.
Inventors
- 👤 Rostislav Didchenko
- 👤 Lawrence Prentiss Lowell Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:44
CPC Classifications
D; D06; D06M; D06M11/00; D06M11/68; D06M11/70; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/16; D06M11/58; D06M11/59; D06M11/60
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
23 words
A process as in claim 1 wherein the ammonia atmosphere contains an inert gas in an amount not exceeding 85 percent by volume.
Claim 2
Dependent Claim
12 words
A process as in claim 2 wherein the inert gas is nitrogen.
Claim 3
Dependent Claim
20 words
A process as in claim 1 wherein the phosphoric acid solution has a concentration of from 1 to 50 percent.
Claim 4
Dependent Claim
23 words
A process as in claim 4 wherein the ammonia atmosphere contains an inert gas in an amount not exceeding 85 percent by volume.
Claim 5
Dependent Claim
12 words
A process as in claim 5 wherein the inert gas is nitrogen.
Claim 6
Dependent Claim
25 words
A process as in claim 1 wherein the phosphoric acid solution is an aqueous solution and has a concentration of from 1 to 50 percent.
Claim 7
Dependent Claim
23 words
A process as in claim 7 wherein the ammonia atmosphere contains an inert gas in an amount not exceeding 85 percent by volume.
Claim 8
Dependent Claim
12 words
A process as in claim 8 wherein the inert gas is nitrogen.
Claim 9
Dependent Claim
20 words
A process as in claim 1 wherein the phosphoric acid solution has a concentration of from 2 to 10 percent.
Claim 10
Dependent Claim
23 words
A process as in claim 10 wherein the ammonia atmosphere contains an inert gas in an amount not exceeding 75 percent by volume.
Claim 11
Dependent Claim
12 words
A process as in claim 11 wherein the inert gas is nitrogen.
Claim 12
Dependent Claim
25 words
A process as in claim 1 wherein the phosphoric acid solution is an aqueous solution and has a concentration of from 2 to 10 percent.
Claim 13
Dependent Claim
23 words
A process as in claim 13 wherein the ammonia atmosphere contains an inert gas in an amount not exceeding 75 percent by volume.
Claim 14
Dependent Claim
12 words
A process as in claim 14 wherein the inert gas is nitrogen.
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |