US4845132A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrophilic porous membrane, method for production thereof, and plasma separator using said membrane
Assignee: Terumo Corp
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Filing: 1987-05-06
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Granted: 1989-07-04
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Expires: 2007-05-06
Abstract
Abstract A hydrophilic porous membrane has graft chains of a hydrophilic monomer formed on the surface of a hydrophobic porous membrane so as to impart to the surface perfect hydrophilicity such that the produced membrane, when wetted, exhibits a swelling ratio of not more than 1% and a bubble point in the range of 0.5 to 8 kg/cm2. The hydrophilic porous membrane is produced by irradiating the hydrophobic porous membrane with plasma, feeding the hydrophilic monomer in a gaseous state, and allowing the hydrophilic monomer to be graft polymerized on the surface of the porous membrane. A plasma separator is obtained by using the aforementioned hydrophilic porous membrane as a plasma separation membrane.
Inventors
- 👤 Toshio Masuoka
- 👤 Okihiko Hirasa
- 👤 Yoshio Suda
- 👤 Makoto Onishi
- 👤 Yukio Seita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:51
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D67/00931; B01D67/009; B01D69/00; B01D69/02; B01D71/00; B01D71/06; B01D71/26; B01D71/262; B01D71/30; B01D71/32; B01D71/34; C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; B01D2323/00; B01D2323/02; B01D2323/38; B01D2325/00; B01D2325/04; B01D2325/38; Y; Y10; Y10S; Y10S521/00; Y10S521/905; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249979
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
86 words
A hydrophilic porous membrane which is characterized by a process of manufacture which comprises forming graft chains of a hydrophilic monomer on the surface of a hydrophobic porous membrane and on the inner surface of the pores, wherein the grafting ratio is in the range of 2 to 30%, thereby imparting to said surfaces perfect hydrophilicity such that the produced membrane, when wetted, exhibits a swelling ratio of not more than 1% and a bubble point in the range of 0.5 to 8 kg/cm 2 .
Claim 2
Dependent Claim
86 words
A hydrophilic porous membrane which is characterized by a process of manufacture which comprises forming graft chains of a hydrophilic monomer on the surface of a hydrophobic porous membrane and on the inner surface of the pores, wherein the grafting ratio is in the range of 2 to 30%, thereby imparting to said surfaces perfect hydrophilicity such that the produced membrane, when wetted, exhibits a swelling ratio of not more than 1% and a bubble point in the range of 0.5 to 8 kg/cm 2 .
Claim 3
Dependent Claim
25 words
A hydrophilic porous membrane according to claim 1, wherein said hydrophobic porous membrane is made of a polyolefin or a partially chlorinated or fluorinated polyolefin.
Claim 4
Dependent Claim
17 words
A hydrophilic porous membrane according to claim 2, wherein said hydrophobic porous membrane is made of polypropylene.
Claim 5
Dependent Claim
18 words
A hydrophilic porous membrane according to claim 1, wherein said hydrophobic porous membrane is made of polyvinylidene fluoride.
Claim 6
Dependent Claim
23 words
A hydrophilic porous membrane according to claim 1, wherein the thickness of said membrane is in the range of 20 to 250 μm.
Claim 7
Dependent Claim
23 words
A hydrophilic porous membrane according to claim 1, wherein said hydrophobic porous membrane possesses no skin layer on the outer surface portion thereof.
Claim 8
Dependent Claim
15 words
A hydrophilic porous membrane according to claim 1, wherein said hydrophilic monomer is N,N-dimethyl acrylamide.
Claim 9
Independent Claim
74 words
A method for the production of a hydrophilic porous membrane, said method comprising irradiating the outer surface of a hydrophobic porous membrane in an unstrained state with plasma and subsequently supplying a hydrophilic monomer in a gaseous state thereby enabling said hydrophilic monomer to be graft polymerized on the surface of said porous membrane and on the inner surface of the pores, wherein the grafting ratio is in the range of 2 to 30%.
Claim 10
Independent Claim
74 words
A method for the production of a hydrophilic porous membrane, said method comprising irradiating the outer surface of a hydrophobic porous membrane in an unstrained state with plasma and subsequently supplying a hydrophilic monomer in a gaseous state thereby enabling said hydrophilic monomer to be graft polymerized on the surface of said porous membrane and on the inner surface of the pores, wherein the grafting ratio is in the range of 2 to 30%.
Claim 11
Dependent Claim
23 words
A method according to claim 8, wherein said hydrophobic porous membrane possesses a wall thickness in the range of 20 to 250 μm.
Claim 12
Dependent Claim
24 words
A method according to claim 8, wherein said hydrophobic porous membrane possesses an average pore diameter in the range of 0.05 to 1.0 μm.
Claim 13
Dependent Claim
23 words
A method according to claim 8, wherein said hydrophobic porous membrane is made of a polyolefin or a partially chlorinated or fluorinated polyolefin.
Claim 14
Dependent Claim
15 words
A method according to claim 11, wherein said hydrophobic porous membrane is made of polypropylene.
Claim 15
Dependent Claim
16 words
A method according to claim 8, wherein said hydrophobic porous membrane is made of polyvinylidene fluoride.
Claim 16
Dependent Claim
13 words
A method according to claim 8, wherein said hydrophilic monomer is N,N-dimethyl acrylamide.
Claim 17
Dependent Claim
98 words
A plasma separator comprising a plasma separation membrane, wherein said plasma separation membrane is a hydrophilic porous membrane which is a process of manufacture which comprises forming graft chains of a hydrophilic monomer on the surface of a hydrophobic porous membrane and on the inner surface of the pores, wherein the grafting ratio is in the range of 2 to 30%, thereby imparting to the surfaces perfect hydrophilicity such that the produced membrane, when wetted, exhibits a swelling ratio of not more than 1% and a bubble point in the range of 0.5 to 8 kg/cm 2 .
Claim 18
Dependent Claim
98 words
A plasma separator comprising a plasma separation membrane, wherein said plasma separation membrane is a hydrophilic porous membrane which is a process of manufacture which comprises forming graft chains of a hydrophilic monomer on the surface of a hydrophobic porous membrane and on the inner surface of the pores, wherein the grafting ratio is in the range of 2 to 30%, thereby imparting to the surfaces perfect hydrophilicity such that the produced membrane, when wetted, exhibits a swelling ratio of not more than 1% and a bubble point in the range of 0.5 to 8 kg/cm 2 .
Claim 19
Dependent Claim
27 words
A plasma separator according to claim 15, wherein said plasma separation membrane possesses a permeability of not less than 90% to total protein component of blood plasma.
Claim 20
Dependent Claim
95 words
A plasma separator according to claim 15, wherein said blood plasma separation membrane is a hydrophilic porous membrane produced by a process which comprises irradiating the outer surface of a hydrophobic porous membrane in an unstrained state with plasma and subsequently causing a hydrophilic monomer supplied in a gaseous form to be graft polymerized onto the surface of said hydrophobic porous membrane and allowing the graft chains formed consequently on the surface of said hydrophobic porous membrane to impart perfect hydrophilicity to said hydrophobic porous membrane to impart perfect hydrophilicity to said hydrophilic porous membrane.
Claim 21
Dependent Claim
24 words
A plasma separator according to claim 15, wherein said hydrophobic porous membrane is made of a polyolefin or a partially chlorinated or fluorinated polyolefin.
Claim 22
Dependent Claim
16 words
A plasma separator according to claim 18, wherein said hydrophobic porous membrane is made of polypropylene.
Claim 23
Dependent Claim
17 words
A plasma separator according to claim 15, wherein said hydrophobic porous membrane is made of polyvinyl fluoride.
Claim 24
Dependent Claim
17 words
A plasma separator according to claim 15, wherein said hydrophilic monomer is 2-hydroxyethyl methacrylate or N,N-dimethyl acrylamide.
Claim 25
Dependent Claim
22 words
A plasma separator according to claim 15, wherein said membrane has a wall thickness in the range of 20 to 250 μm.
Claim 26
Dependent Claim
39 words
A plasma separator according to claim 15, wherein said hydrophilic porous membrane, when wetted, shows a swelling ratio in the range of 0 to 0.5% and a bubble point in the range of 0.8 to 2.0 kg/cm 2 .
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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) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |