US3726934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the separation of styrene from ethyl benzene
Assignee: Monsanto Co
•
Filing: 1971-12-20
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Granted: 1973-04-10
•
Expires: 1991-12-20
Abstract
Abstract Styrene is separated from organic mixtures comprising styrene and ethyl benzene by contacting the mixture against one side of a polymeric membrane and withdrawing at the other side a vaporous mixture having increased styrene concentration. The polymer membrane is an acrylonitrile-containing polymer or acrylonitrilecontaining polymer blend. Exemplary of the polymer membranes are copolymers of acrylonitrile and acrylic acid, 2-methyl-5vinylpyridine, isobutylene, isoprene, and styrene and blends of polyacrylonitrile and poly(ethylenimine).
Inventors
- 👤 W Strazik
- 👤 E Perry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:03
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/36; B01D61/362; B01D71/00; B01D71/06; B01D71/40; B01D71/42; B01D71/421; C; C07; C07C; C07C7/00; C07C7/144
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
32 words
The process of claim 1 wherein the pressure on the second side of the membrane is less than atmospheric pressure and lower than the pressure on the other side of the membrane.
Claim 2
Dependent Claim
13 words
The process of claim 1 wherein the feed mixture is a liquid mixture.
Claim 3
Dependent Claim
31 words
The process of claim 1 wherein the membrane comprises a copolymer of (a) acrylonitrile and (b) a member selected from the group consisting of acrylic acid, methylvinylpyridine, isobutylene, isoprene and styrene.
Claim 4
Dependent Claim
12 words
THe process of claim 1 wherein the membrane comprises a polymer blend.
Claim 5
Dependent Claim
10 words
The process of claim 5 wherein the membrane is polyacylonitrile/poly(ethylenimine).
References Cited (Backward Citations)
US2958657A
Cited
US2947687A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |