US3640285A
Expired / Lapsed
US
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Cigarette paper and method for preparation
Assignee: Gallaher Ltd
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Filing: 1968-12-17
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Granted: 1972-02-08
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Expires: 1988-12-17
Abstract
Abstract Cigarette paper having improved taste and aroma during pyrolysis wherein the paper is loaded with an agent comprising up to 45 percent by weight calcium oxalate preferably formed in situ internally in the paper fibers and/or conversion of the cellulosic fibers by selective oxidation to convert preferably 40 to 60 percent of the methylol groups on the C6 position to carboxylic acid groups and further treatments.
Inventors
- 👤 Theodore Briskin
- 👤 Geoffrey R Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:20
CPC Classifications
A; A24; A24D; A24D1/00; A24D1/02; A24B; A24B15/00; A24B15/10; A24B15/16; D; D21; D21H; D21H5/00; D21H5/12; D21H5/14; D21H5/16
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
23 words
The method as claimed in claim 1 in which the cation is selected from the group consisting of calcium, magnesium, strontium, and barium.
Claim 2
Dependent Claim
41 words
The method as claimed in claim 1 in which the ashing ingredient comprises a mixture of calcium oxalate and magnesium oxalate present in the ratio of one part by weight magnesium oxalate to one to four parts by weight calcium oxalate.
Claim 3
Dependent Claim
49 words
The method as claimed in claim 1 in which the ashing ingredient is introduced by the steps of wetting the cellulosic material with the salt while in a solubilized state in aqueous medium and aging the treated fibers to precipitate the salt in situ within the cellulosic fibrous structure.
Claim 4
Dependent Claim
36 words
The method as claimed in claim 4 comprising the steps of providing one aqueous solution containing the cation and a second aqueous solution containing the anion and substantially simultaneously wetting the cellulosic material with the solutions.
Claim 5
Dependent Claim
20 words
The method as claimed in claim 5 in which the solutions are admixed immediately prior to wetting the cellulosic material.
Claim 6
Dependent Claim
20 words
The method as claimed in claim 5 in which the solutions are separately applied substantially simultaneously onto the cellulosic material.
Claim 7
Dependent Claim
53 words
The method as claimed in claim 1 in which the ashing ingredient is introduced into the cellulosic fibers prior to paper formation and which includes the step of forming the ceLlulosic fibers into a thin paper wrapper and rinsing the formed paper with water to remove water solubles and then drying the paper.
Claim 8
Dependent Claim
55 words
The method as claimed in claim 8 which includes the step of introducing an acid into the treated paper in an amount up to 0.5 percent by weight of the paper in which the acid is selected from the group consisting of oxalic acid, tannic acid, pivalic acid, glycolic acid, diglycolic acid, and lactic acid.
Claim 9
Dependent Claim
14 words
The method as claimed in claim 8 in which the acid is oxalic acid.
Claim 10
Dependent Claim
51 words
The method as claimed in claim 1 in which the salt is present in an amount of at least 5 percent by weight of the cellulosic fibers and the remainder making up the ashing component is a filler selected from the group consisting of perlite, talc, alumina, silica, and calcium carbonate.
Claim 11
Dependent Claim
44 words
The method as claimed in claim 1 which includes the additional step of oxidizing the cellulosic material with nitrogen dioxide selectively to oxidize methylol groups on the C6 position of the cellulosic molecule by an amount within the range of 15 to 60 percent.
Claim 12
Dependent Claim
40 words
The method as claimed in claim 12 in which the nitrogen dioxide oxidizing medium is liquid nitrogen dioxide and which includes the step of separating the liquid oxidizing medium from the oxidized cellulosic fiber upon completion of the oxidation reaction.
Claim 13
Dependent Claim
27 words
The method as claimed in claim 12 in which the cellulosic material is oxidized by an amount insufficient to destroy the fibrous characteristics of the cellulosic material.
Claim 14
Dependent Claim
25 words
The method as claimed in claim 12 in which the cellulosic material is oxidized by an amount within the range of 40 to 60 percent.
Claim 15
Dependent Claim
26 words
The method as claimed in claim 13 which includes the step of bubbling an oxygen containing gas through the liquid nitrogen dioxide during the oxidation reaction.
Claim 16
Dependent Claim
21 words
The method as claimed in claim 12 in which the liquid oxidizing medium contains up to 8 percent by weight water.
Claim 17
Dependent Claim
26 words
The method as claimed in claim 17 in which the amount of water is within the range of 0.5 to 5 percent in the oxidizing medium.
Claim 18
Dependent Claim
25 words
The method as claimed in claim 13 in which the oxidation is carried out at a temperature within the range of 15* to 65* C.
Claim 19
Dependent Claim
32 words
The method as claimed in claim 13 which includes the step of rinsing the oxidized fibers with anhydrous liquid nitrogen dioxide after separating the liquid oxidizing medium from the oxidized cellulose fibers.
Claim 20
Dependent Claim
22 words
The method as claimed in claim 12 which includes the step of subjecting the oxidized cellulosic material to a mild reduction reaction.
Claim 21
Dependent Claim
31 words
The method as claimed in claim 21 in which the reduction reaction is carried out with a reducing agent selected from the group consisting of freshly prepared hydrogen and a borohydrate.
Claim 22
Dependent Claim
55 words
The method as claimed in claim 12 which includes the step of adding an acid to the dried oxidized cellulosic material in an amount up to 5 percent by weight and in which the acid is selected from the group consisting of oxalic acid, tannic acid, pivalic acid, glycolic acid, diglycolic acid, and lactic acid.
Claim 23
Dependent Claim
15 words
The method as claimed in claim 23 in which the applied acid is oxalic 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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |