Patent US4713292A successfully refreshed from Google Patents.
US4713292A
Expired / Lapsed
US
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Multilayer composite hollow fibers and method of making same
Assignee: Mitsubishi Chemical Corp
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Filing: 1986-06-26
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Granted: 1987-12-15
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Expires: 2006-06-26
Abstract
Abstract Disclosed are a multilayer composite hollow fiber comprising at least one nonporous separating membrane layer (A) performing a separating function and two or more porous layers (B) performing a reinforcing function, the layer (A) and the layers (B) being alternately laminated so as to give a structure having internal and external surfaces formed by the porous layers (B), as well as a method of making such a hollow fiber. In this multilayer composite hollow fiber, the separating membrane can be formed as an ultrathin, homogeneous membrane. Moreover, the separating membrane is not liable to get damaged owing to the unique structure of the hollow fiber. Furthermore, such hollow fibers can be readily and stably produced on an industrial scale.
Inventors
- 👤 Tohru Takemura
- 👤 Hajime Itoh
- 👤 Jun Kamo
- 👤 Haruhiko Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:53
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/24; B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/0025; B01D67/0027; B01D69/00; B01D69/08; B01D69/12; B01D69/1213; B01D69/1216; B01D2323/00; B01D2323/08; B01D2323/081; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2929; Y10T428/2933; Y10T428/2935; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
56 words
A multilayer composite hollow fiber comprising at least one nonporous separating membrane layer (A) performing a separating function and two or more porous layers (B) performing a reinforcing function, said layer (A) and said layers (B) being alternately laminated so as to give a structure having inner and outer surfaces formed by said porous layers (B).
Claim 2
Dependent Claim
56 words
A multilayer composite hollow fiber comprising at least one nonporous separating membrane layer (A) performing a separating function and two or more porous layers (B) performing a reinforcing function, said layer (A) and said layers (B) being alternately laminated so as to give a structure having inner and outer surfaces formed by said porous layers (B).
Claim 3
Dependent Claim
47 words
The multilayer composite hollow fiber as claimed in claim 1 wherein said hollow fiber has an internal diameter of 0.1 to 5.0 mm and a wall thickness of 10 to 1000 μm and said separating membrane layer (A) has a thickness of not greater than 5 μm.
Claim 4
Dependent Claim
21 words
The multilayer composite hollow fiber as claimed in claim 1 where said porous layers (B) consist of a crystalline thermoplastic polymer.
Claim 5
Dependent Claim
25 words
The multilayer composite hollow fiber as claimed in claim 2 wherein said separating membrane layer (A) has a thickness of not greater than 2 μm.
Claim 6
Dependent Claim
40 words
The multilayer composite hollow fiber as claimed in claim 1, wherein said separating membrane layer (A) is prepared from a polymer selected from the group consisting of silicones, polyurethanes, cellulosic materials, polyolefins, polysulfones, polyvinyl alcohol, polyesters, polyethers, polyamides and polyimides.
Claim 7
Dependent Claim
22 words
The multilayer composite hollow fiber as claimed in claim 1, wherein said porous layers (B) are prepared from a crystalline thermoplastic polymer.
Claim 8
Dependent Claim
22 words
The multilayer composite hollow fiber as claimed in claim 6, wherein said thermoplastic polymer is a polyolefin, a polycarbonate or a polyester.
Claim 9
Dependent Claim
21 words
The multilayer composite hollow fiber as claimed in claim 1, wherein the membrane material of said layer (A) contains a plasticizer.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-12-14 | 1991-06-15 | 1991-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-14 | 1995-06-15 | 1995-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-14 | 1999-06-15 | 1999-12-15 | $7700.00 | Window Closed / Lapsed |