Patent US2546493A successfully refreshed from Google Patents.
Patent US3557801A successfully refreshed from Google Patents.
US3557801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cigarette smoke filter material
Assignee: Celanese Corp
•
Filing: 1968-09-16
•
Granted: 1971-01-26
•
Expires: 1988-09-16
Abstract
Abstract A cigarette filter plug is disclosed which is made from filaments characterized by alternating regions of large and small diameter prepared by dry spinning a solution of cellulose ester containing a plasticizer and solid solvent adsorbent particles and then passing the resultant filaments over a hot surface. The solid particles found suitable may be activated charcoal, other types of activated carbon, silica gel, alumina or clay.
Inventors
- 👤 Saunders E Jamison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:52
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/06; A24D3/16; A24D3/08; A24D3/10; D; D01; D01D; D01D5/00; D01D5/20
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
19 words
The filaments of claim 1 in which the thermoplastic filamentary material comprises a cellulose ester of an organic acid.
Claim 2
Dependent Claim
14 words
The filaments of claim 1 in which the thermoplastic filamentary material comprises cellulose acetate.
Claim 3
Dependent Claim
14 words
The filaments of claim 1 in which the adsorbent solid particles comprise activated charcoal.
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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |