US4568579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Asymmetrical layered structures of polyalkylene sulfone resins
Assignee: OI Glass Inc
•
Filing: 1983-11-03
•
Granted: 1986-02-04
•
Expires: 2003-11-03
Abstract
Abstract Asymmetrical layered structures such as asymmetrical films are disclosed. The main body section contains a multitude of pores (voids). A thin surface skin is free of pores. The entire structure is fabricated from a polyalkylene sulfone resin in which the alkylene moiety contains 6 to 18 carbon atoms. Processes for preparing the structures also are disclosed. The structures are semi-permeable to gases and are used as membranes to enrich the oxygen content of oxygen/nitrogen mixtures.
Inventors
- 👤 Barry Watson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:11
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; B01D67/00111; B01D71/00; B01D71/06; B01D71/66; B01D71/68; B01D2325/00; B01D2325/02; B01D2325/022; C08J2381/00; C08J2381/06; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1376; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/26; Y10T428/266; Y10T428/31504; Y10T428/31855; Y10T428/31931
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
122 words
An asymmetrical layered structure of a polyalkylene sulfone resin comprising: (a) the principal body section of the structure has a multitude of small pores distributed substantially uniformly therethrough, (b) one surface of the structure is homogeneous and substantially free of pores, (c) the cross-sectional thickness of surface (b) is substantially thinner than the cross-sectional thickness of the principal body section (a), and (d) the polymerized alkylene in said polyalkylene sulfone resin is an alpha alkylene which contains 6 to 18 carbon atoms, the structure having an oxygen permeation flux of at least about 1×10 -6 (cm 3 at STP)·cm -2 ·sec -1 ·cm Hg -1 as measured across an area of 1 cm 2 at a pressure differential of 1 cm Hg.
Claim 2
Dependent Claim
122 words
An asymmetrical layered structure of a polyalkylene sulfone resin comprising: (a) the principal body section of the structure has a multitude of small pores distributed substantially uniformly therethrough, (b) one surface of the structure is homogeneous and substantially free of pores, (c) the cross-sectional thickness of surface (b) is substantially thinner than the cross-sectional thickness of the principal body section (a), and (d) the polymerized alkylene in said polyalkylene sulfone resin is an alpha alkylene which contains 6 to 18 carbon atoms, the structure having an oxygen permeation flux of at least about 1×10 -6 (cm 3 at STP)·cm -2 ·sec -1 ·cm Hg -1 as measured across an area of 1 cm 2 at a pressure differential of 1 cm Hg.
Claim 3
Dependent Claim
14 words
An article of claim 1 in which the layered structure is an asymmetrical film.
Claim 4
Dependent Claim
17 words
An article of claim 1 in which the layered structure is a tube having an asymmetrical wall.
Claim 5
Dependent Claim
45 words
An asymmetrical structure of claim 1 which has an oxygen permeation flux of at least about 9.8×10 -6 (cm 3 at STP)·cm -2 ·sec -1 ·cm Hg -1 as measured across an area of 1 cm 2 at a pressure differential of 1 cm Hg.
Claim 6
Dependent Claim
25 words
An asymmetrical structure of claim 1 in which the ratio of the oxygen permeation flux to the nitrogen permeation flux is at least about 2.0.
Claim 7
Dependent Claim
64 words
An asymmetrical film of claim 2 which has an oxygen permeation flux of at least about 1×10 -6 (cm 3 at STP)·cm -2 ·sec -1 ·cm Hg -1 as measured across an area of 1 cm 2 at a pressure differential of 1 cm Hg, the principal body section (a) having a thickness of about 0.004 to 0.02 inch, as illustrated in Table II.
Claim 8
Dependent Claim
25 words
An asymmetrical film of claim 2 in which the ratio of the oxygen permeation flux to the nitrogen permeation flux is at least about 2.0.
Claim 9
Dependent Claim
20 words
An asymmetrical structure of claim 1 in which the polymerized alkylene in said polyalkylene sulfone resin contains 6 carbon atoms.
Claim 10
Dependent Claim
20 words
An asymmetrical structure of claim 1 in which the polymerized alkylene in said polyalkylene sulfone resin contains 8 carbon atoms.
Claim 11
Dependent Claim
20 words
An asymmetrical structure of claim 1 in which the polymerized alkylene in said polyalkylene sulfone resin contains 10 carbon atoms.
Claim 12
Dependent Claim
20 words
An asymmetrical structure of claim 1 in which the polymerized alkylene in said polyalkylene sulfone resin contains 16 carbon atoms.
References Cited (Backward Citations)
US3928294A
Cited
US4179757A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |