Patent US3577994A successfully refreshed from Google Patents.
US3577994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing smoking product of oxidized cellulosic material
Assignee: Gallaher Ltd
•
Filing: 1968-11-07
•
Granted: 1971-05-11
•
Expires: 1988-11-07
Abstract
Abstract The method for rapidly and uniformly effecting selective oxidation of cellulosic materials used in the preparation of a smokable product embodying the sequence of steps of soaking the cellulosic material with liquid nitrogen dioxide and then exposing the cellulosic material to hot gaseous nitrogen dioxide for oxidation reaction and wherein the liquid nitrogen dioxide may contain up to 8 percent by weight water.
Inventors
- 👤 Geoffrey R Ward
- 👤 Howard F Keller Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:46
CPC Classifications
A; A24; A24B; A24B15/00; A24B15/10; A24B15/16; A24B15/165; C; C08; C08B; C08B15/00; C08B15/02; C08B15/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
20 words
The method as claimed in claim 1 in which the gaseous nitrogen dioxide reaction is carried out at elevated temperature.
Claim 2
Dependent Claim
25 words
The method as claimed in claim 2 in which the reaction is carried out at a temperature within the range of 30* to 220* C.
Claim 3
Dependent Claim
31 words
The method as claimed in claim 1 in which the reaction with gaseous nitrogen dioxide is carried out at a pressure of about atmospheric pressure to slightly less than atmospheric pressure.
Claim 4
Dependent Claim
31 words
The method as claimed in claim 1 in which the liquid nitrogen dioxide with which the cellulosic material is wet contains water in an amount up to 4 percent by weight.
Claim 5
Dependent Claim
36 words
The method as claimed in claim 1 in which the liquid nitrogen dioxide with which the cellulosic material is wet contains water in an amount within the range of 0.5 percent to 1.5 percent by weight.
Claim 6
Dependent Claim
25 words
The method as claimed in claim 1 in which the liquid nitrogen dioxide is at a temperature within the range of -1* to 21* C.
Claim 7
Dependent Claim
63 words
In the method of rapidly and uniformly selectively oxidizing cellulosic material for use in the preparation of a smokable product, the sequence of steps of wetting relatively pure cellulosic material with nitrogen dioxide, drying the cellulosic material after so wetting it and then wetting it and then reacting the cellulosic material which has been wet with liquid nitrogen dioxide with gaseous nitrogen dioxide.
Claim 8
Dependent Claim
28 words
The method as claimed in claim 8 which comprises repeating the cycle a number of times until the desired level of conversion of methylol groups has been achieved.
Claim 9
Dependent Claim
27 words
The method as claimed in claim 9 in which the cycle is repeated until more than 90 percent of the methylol groups have been converted by oxidation.
Claim 10
Dependent Claim
111 words
In the method of rapidly and uniformly selectively oxidizing cellulosic material for use in the preparation of smokable product, the sequence of steps of wetting relatively cellulosic material with nitrogen dioxide, and then reacting the cellulosic material which has been wet with liquid nitrogen dioxide with gaseous nitrogen dioxide, the said reaction being carried out in a vessel partially filled with nitrogen dioxide whereby liquid nitrogen dioxide is in the bottom portion of the vessel and the space above the liquid nitrogen dioxide is filled with gaseous nitrogen dioxide and in which a strip of cellulosic material is continuously advanced for alternate immersion in the liquid and exposure to the vapor.
Claim 11
Dependent Claim
97 words
In the method of rapidly and uniformly selectively oxidizing cellulosic material for use in the preparation of a smokable product, the sequence of steps of wetting relatively pure cellulosic material with nitrogen dioxide, and then reacting the cellulosic material which has been wet with liquid nitrogen dioxide with gaseous nitrogen dioxide with gaseous nitrogen dioxide, the said reaction being carried out in an elongate tubular member having a number of spray positions, through which a strip of cellulosic material is pulled, passing gaseous nitrogen dioxide through the tubular member, and intermittently spraying the strip with nitrogen dioxide.
Claim 12
Dependent Claim
103 words
In the method of rapidly and uniformly selectiveLy oxidizing cellulosic material for use in the preparation of a smokable product, the sequence of steps of wetting relatively pure cellulosic material with nitrogen dioxide, and then reacting the cellulosic material which has been wet with liquid nitrogen dioxide with gaseous nitrogen dioxide, the said reaction is carried out by passing a strip of cellulosic material in a sinuous path about roller''s within a chamber saturated with hot gaseous nitrogen dioxide, refrigerating at least some of the rollers to condense gaseous nitrogen dioxide on the periphery thereof to wet strip as it is passed thereabout.
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) | 1974-05-10 | 1974-11-09 | 1975-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-10 | 1978-11-09 | 1979-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-10 | 1982-11-09 | 1983-05-11 | $7700.00 | Window Closed / Lapsed |