Patent US4033731A successfully refreshed from Google Patents.
US4033731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Partially crosslinked silalactone polymers, their preparation and their use
Assignee: Rhone Poulenc SA
•
Filing: 1975-07-29
•
Granted: 1977-07-05
•
Expires: 1995-07-29
Abstract
Abstract Linear homopolymers of 3,5,5-trimethyl-5-sila- delta -valerolactone are crosslinked through the 5-methyl group, e.g. by heating with an organic peroxide, to give polymers. Films of these crosslinked polymers have a critical surface tension similar to Teflon and can be used for water proofing. The films also exhibit selective permeability to gases and can be used to reduce the CO2 content of CO2/O2 mixtures.
Inventors
- 👤 Michel Bargain
- 👤 Zeno Pasquini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:17
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/70; C; C08; C08G; C08G63/00; C08G63/68; C08G63/91; C08G63/912
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
83 words
A method of separating at least one gas component from a gaseous mixture of at least two of oxygen, nitrogen and carbon dioxide which comprises bringing the gaseous mixture into contact with one side of a membrane having selective permeability to gases comprising a 3,5,5,-trimethyl-1-oxa-5-sila-cyclohexan-2-one polymer having repeat units of Formula I: ##STR4## at least some of the units being cross-linked to one another and recovering from the other side of the membrane a gaseous mixture enriched in at least one gas component.
Claim 2
Independent Claim
83 words
A method of separating at least one gas component from a gaseous mixture of at least two of oxygen, nitrogen and carbon dioxide which comprises bringing the gaseous mixture into contact with one side of a membrane having selective permeability to gases comprising a 3,5,5,-trimethyl-1-oxa-5-sila-cyclohexan-2-one polymer having repeat units of Formula I: ##STR4## at least some of the units being cross-linked to one another and recovering from the other side of the membrane a gaseous mixture enriched in at least one gas component.
Claim 3
Dependent Claim
76 words
A method according to claim 1 in which the polymer consists essentially of repeat units of Formula I, of Formula II and of Formula III: ##STR5## in which the 5-methylene -- CH 2 -- group(s) in unit II and unit III is directly bonded to a 5-methylene --CH 2 -- group(s) in another unit II or unit III and each oxygen atom in a repeat unit is bonded to a CO group in another repeat unit.
Claim 4
Dependent Claim
41 words
A method according to claim 1 in which the carboxylic chain end of the polymer is blocked with a blocking group for carboxylic groups and the hydroxy chain end of the polymer is blocked with a blocking group for hydroxy groups.
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) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |