Patent US3767502A successfully refreshed from Google Patents.
US3767502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing a supported semipermeable membrane which does not require end sealing
Assignee: Daicel Corp
•
Filing: 1971-12-29
•
Granted: 1973-10-23
•
Expires: 1991-12-29
Abstract
Abstract A supported semipermeable membrane is prepared by affixing sealing members to the end of a permeable support and then applying a semipermeable membrane forming solution on the support and the sealing members to cover them with a continuous semipermeable membrane, said sealing members being made of a material which can be dissolved by the semipermeable membrane forming solution to form a welded unity with the semipermeable membrane, whereby the ends of the membrane are sealed without the use of an adhesive.
Inventors
- 👤 K Ishii
- 👤 S Konomi
- 👤 Y Ishiguro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:01
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/08; B01D63/081; B01D67/00; B01D67/0002; B01D67/0009; B01D67/00091; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/16; B01D2313/00; B01D2313/04; B01D2313/041
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
19 words
A process according to claim 1, in which said sealing members and semipermeable membrane are made of cellulose acetate.
Claim 2
Dependent Claim
19 words
A process according to claim 1, in which said sealing members are preformed members adhesively united to said support.
Claim 3
Dependent Claim
43 words
A process according to claim 1, in which said sealing members are formed on said support, in advance of the forming of said layer, by applying a separate semipermeable membrane forming solution only to the ends of said support and then drying same.
Claim 4
Dependent Claim
24 words
A process according to claim 1, in which said treating step comprises immersing said film in ice water and then heat treating the film.
References Cited (Backward Citations)
US2241355A
Cited
US3421782A
Cited
US3480147A
Cited
US3542204A
Cited
US3610418A
Cited
US3657402A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |