US4401567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microporous polyethylene hollow fibers
Assignee: Mitsubishi Chemical Corp
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Filing: 1981-07-07
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Granted: 1983-08-30
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Expires: 2001-07-07
Abstract
Abstract Porous hollow fibers composed of a high density polyethylene the fibers having rectangular micropores that are oriented in the lengthwise direction of the fibers and having a porosity from 30 to 90% by volume are disclosed. Membranes composed of hollow fibers exhibit a water permeability of greater than 65 (ml/m2, hr, mmHg) as well as a human serum albumin permeability of greater than 30%. Such fibers are suited for use as filters, particularly as a membrane for simple fractionation of whole blood into its plasma and cellular components. The hollow fibers are obtained by spinning a high-density polyethylene under a high-draft condition followed by cold stretching and hot stretching, and without the use of any solvent or plasticizer.
Inventors
- 👤 Mizuo Shindo
- 👤 Takashi Yamamoto
- 👤 Osamu Fukunaga
- 👤 Hisayoshi Yamamori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:44
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/24; B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/0025; B01D67/0027; B01D69/00; B01D69/02; B01D69/08; B01D71/00; B01D71/06; B01D71/26; B01D71/261; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2935; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
A high-density polyethylene microporous hollow fiber which is oriented in the lengthwise direction of the fiber, said hollow fiber having: (a) rectangular pores formed by microfibrils that are oriented in the lengthwise direction of the fiber and knotted portions that are connected to said microfibrils substantially at right angles thereto, the pores being contiguous with each other from the inner wall surface to the outer wall surface to form a stacked, multicellular structure; (b) a porosity of about 30 to about 90% by volume; (c) a water permeability through the wall of at least about 65 (ml/m 2 .hr.mmHg); and (d) a human serum albumin permeability of at least about 30% as measured in a physiological saline solution.
Claim 2
Dependent Claim
118 words
A high-density polyethylene microporous hollow fiber which is oriented in the lengthwise direction of the fiber, said hollow fiber having: (a) rectangular pores formed by microfibrils that are oriented in the lengthwise direction of the fiber and knotted portions that are connected to said microfibrils substantially at right angles thereto, the pores being contiguous with each other from the inner wall surface to the outer wall surface to form a stacked, multicellular structure; (b) a porosity of about 30 to about 90% by volume; (c) a water permeability through the wall of at least about 65 (ml/m 2 .hr.mmHg); and (d) a human serum albumin permeability of at least about 30% as measured in a physiological saline solution.
Claim 3
Dependent Claim
118 words
A microporous hollow fiber according to claim 1 wherein the microfibrils have an average thickness (d M ) of about 0.02 to 0.3 microns and an average length (l M ) of about 0.5 to 6.0 microns, the knotted portions have an average length (l K ) of about 0.1 to 6.0 microns in the lengthwise direction of the fiber, the ratio of the average length (l V ) to an average width (d V ) of the rectangular pores is within the range of from about 3 to 50, and the ratio d V /d M of the width of the pores to the thickness of the microfibrils is within the range of about 0.3 to 5.0.
Claim 4
Dependent Claim
27 words
The microporous hollow fiber according to claim 1 or 2, wherein said hollow fiber is made from a high-density polyethylene having a density of at least 0.960.
Claim 5
Dependent Claim
25 words
The microporous hollow fiber according to claim 3 wherein said hollow fiber is made from a high-density polyethylene having a density of at least 0.965.
Claim 6
Dependent Claim
28 words
The microporous hollow fiber according to claim 1 or 2, wherein water permeability through the wall of the hollow fiber is at least about 300 (ml/m 2 .hr.mmHg).
Claim 7
Dependent Claim
44 words
A microporous hollow fiber according to claim 1 or 2, wherein water permeability through the wall of the hollow fiber is at least 1000 (ml/m 2 .hr.mmHg) and the human serum albumin permeability is at least 60% as measured in a physiological saline solution.
Claim 8
Dependent Claim
23 words
A microporous hollow fiber according to claim 1 made from polyethylene having a melt index of from at least 1 up to 15.
Claim 9
Dependent Claim
23 words
A microporous hollow fiber according to claim 7 made from a polyethylene having a melt index of from about 3 to about 7.
Claim 10
Dependent Claim
120 words
A high-density polyethylene microporous hollow fiber membrane which is oriented in the lengthwise direction of the fiber, said hollow fiber membrane having: (a) rectangular pores formed by microfibrils that are oriented in the lengthwise direction of the fiber and knotted portions that are connected to said microfibrils substantially at right angles thereto, the pores being contiguous with each other from the inner wall surface to the outer wall surface to form a stacked, multicellular structure; (b) a porosity of about 30 to about 90% by volume; (c) a water permeability through the wall of at least about 65 (ml/m 2 .hr.mmHg); and (d) a human serum albumin permeability of at least about 30% as measured in a physiological saline solution.
Claim 11
Dependent Claim
120 words
A high-density polyethylene microporous hollow fiber membrane which is oriented in the lengthwise direction of the fiber, said hollow fiber membrane having: (a) rectangular pores formed by microfibrils that are oriented in the lengthwise direction of the fiber and knotted portions that are connected to said microfibrils substantially at right angles thereto, the pores being contiguous with each other from the inner wall surface to the outer wall surface to form a stacked, multicellular structure; (b) a porosity of about 30 to about 90% by volume; (c) a water permeability through the wall of at least about 65 (ml/m 2 .hr.mmHg); and (d) a human serum albumin permeability of at least about 30% as measured in a physiological saline solution.
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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) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |