US3871950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hollow fibers of acrylonitrile polymers for ultrafilter and method for producing the same
Assignee: Asahi Kasei Corp
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Filing: 1973-04-26
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Granted: 1975-03-18
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Expires: 1993-04-26
Abstract
Abstract Hollow fibers of acrylonitrile polymers having waterpermeability greater than 0.2 ml/cm2.min.atm and useful as an inexpensive superior ultrafilter, comprising 1. A POROUS LAYER OR LAYERS EXISTING ON THE OUTER OR/AND INNER SIDES OF SAID HOLLOW FIBERS, THE AVERAGE SIZES OF PORES CONTAINED IN SAID POROUS LAYER OR LAYERS AND EXISTING ON EACH OF ASSUMPTIVE CYLINDRICAL SURFACES CONCENTRIC WITH THE CENTRAL AXIS OF SAID HOLLOW FIBERS, HAVING SUCH A GRADIENT THAT THE AVERAGE SIZES OF PORES CONTAINED IN THE POROUS LAYER EXISTING ON THE OUTER SIDE BECOME SMALLER TOWARD THE OUTER SURFACE OF SAID HOLLOW FIBERS WHILE THE AVERAGE SIZES OF PORES CONTAINED IN THE POROUS LAYER EXISTING ON THE INNER SIDE BECOME SMALLER TOWARD THE INNER SURFACE OF SAID HOLLOW FIBERS, AND 2. A RETICULATE POROUS LAYER ADJACENT TO SAID POROUS LAYER OR LAYERS (1) AND CONTAINING THEREIN AT LEAST ONE SUCCESSION OF VOIDS HAVING DIAMETERS OF AT LEAST 10 - 50 Mu , ARE PREPARED BY DISSOLVING AN ACRYLONITRILE POLYMER IN AN AQUEOUS SOLUTION OF NITRIC ACID OF 65 - 95% BY WEIGHT CONCENTRATION AND EXTRUDING THE RESULTING SPINNING SOLUTION THROUGH A DIE FOR HOLLOW FIBERS, INTO A COAGULATION BATH CONTAINING WATER OR AN AQUEOUS SOLUTION OF NITRIC ACID OF 30% BY WEIGHT OR LESS CONCENTRATION.
Inventors
- 👤 Yasuo Hashino
- 👤 Masatsugu Yoshino
- 👤 Hitoshi Sawabu
- 👤 Tsugio Konno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:20
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/40; B01D71/42; B01D71/421; B01D61/00; B01D61/14; B01D61/18; B01D63/00; B01D63/02; B01D63/021; D; D01; D01D; D01D5/00; D01D5/24; D01D5/247; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2973; Y10T428/2975; Y10T428/2978; Y10T428/298
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
37 words
A HOLLOW FIBER OF ACRYLONITRILE POLYMER FOR ULTRAFILTER, HAVING A WATER-PERMEABILITY GREATER THAN 0.2 ML/CM2. MIN. ATM.; SAID ACRYLONITRILE POLYMER CONTAINING AT LEAST 60% BY MOL OF ACRYLONITRILE UNITS; AND HOLLOW FIBER HAVING A STRUCTURE CONSISTING OF:
Claim 2
Dependent Claim
37 words
A HOLLOW FIBER OF ACRYLONITRILE POLYMER FOR ULTRAFILTER, HAVING A WATER-PERMEABILITY GREATER THAN 0.2 ML/CM2. MIN. ATM.; SAID ACRYLONITRILE POLYMER CONTAINING AT LEAST 60% BY MOL OF ACRYLONITRILE UNITS; AND HOLLOW FIBER HAVING A STRUCTURE CONSISTING OF:
Claim 3
Dependent Claim
148 words
A RETICULATE POROUS REGION CONCENTRIC WITH THE CENTRAL AXIS OF SAID HOLLOW FIBER, THE PORES OF SAID RETICULATE POROUS REGION BEING ESSENTIALLY OF THE SAME SIZE; SAID RETUCULATE POROUS REGION INCLUDING THEREWITHIN AT LEAST ONE SUCESSSION OF VOIDS CONCENTRIC WITH THE CENTRAL AXIS OF SAID REVOLVING ELLIPSOID SHAPE HAVING A DIAMETER IN THE DIRECREVOLVING ELLIPSOID SHAPE HAVING A DIAMETER IN THE DIRECTION OF ITS SHORT AXIS OF 10 TO 50 U AND A LONG AXIS THAT POINTS ESSENTIALLY TOWARD THE CENTRAL AXIS OF SAID HOLLOW FIBERS AND A CROSS-SECTION PERPENDICULAR TO THE LONG AXIS THAT IS NEARLY CIRCULAR; THE LENGTH OF THE LONG AXES OF SAID VOIDS BEING AT LEAST TWO TIMES THE DIAMETERS OF THEIR CROSSSECTIONS AND THE DIAMETERS OF THEIR CROSS SECTIONS BEING ALMOST EQUAL ON THE SAME ASSUMPTIVE CYLINDRICAL SURFACES WHOSE CONTRAL AXES ARE THE SAME AS THE CENTRAL AXIS OF SAID HOLLOW FIBERS, AND
Claim 4
Dependent Claim
148 words
A RETICULATE POROUS REGION CONCENTRIC WITH THE CENTRAL AXIS OF SAID HOLLOW FIBER, THE PORES OF SAID RETICULATE POROUS REGION BEING ESSENTIALLY OF THE SAME SIZE; SAID RETUCULATE POROUS REGION INCLUDING THEREWITHIN AT LEAST ONE SUCESSSION OF VOIDS CONCENTRIC WITH THE CENTRAL AXIS OF SAID REVOLVING ELLIPSOID SHAPE HAVING A DIAMETER IN THE DIRECREVOLVING ELLIPSOID SHAPE HAVING A DIAMETER IN THE DIRECTION OF ITS SHORT AXIS OF 10 TO 50 U AND A LONG AXIS THAT POINTS ESSENTIALLY TOWARD THE CENTRAL AXIS OF SAID HOLLOW FIBERS AND A CROSS-SECTION PERPENDICULAR TO THE LONG AXIS THAT IS NEARLY CIRCULAR; THE LENGTH OF THE LONG AXES OF SAID VOIDS BEING AT LEAST TWO TIMES THE DIAMETERS OF THEIR CROSSSECTIONS AND THE DIAMETERS OF THEIR CROSS SECTIONS BEING ALMOST EQUAL ON THE SAME ASSUMPTIVE CYLINDRICAL SURFACES WHOSE CONTRAL AXES ARE THE SAME AS THE CENTRAL AXIS OF SAID HOLLOW FIBERS, AND
Claim 5
Dependent Claim
143 words
A GRADIENT-TYPE POROUS REGION ADJACENT TO THE OUTER PORTION OF SAID RETICULATE POROUS REGION OR TO EACH OF THE OUTER AND INNER PORTIONS OF SAID RETICULATE POROUS REGION AND CONCENTRIC WITH THE RETICULATE POROUS REGION AND THE CENTRAL AXIS OF SAID HOLOW FIBER, THE SIZE OF PORES IN THE GRADIENT-TYPE POROUS REGION HAVING A GRADIENT IN THAT THE AVERAGE SIZE OF PORES CONTAINED IN A GRADIENT-TYPE POROUS REGION BECOMES SMALLER TOWARD THE OUTER SURFACE OF SAID HOLLOW FIBERS AND THE AVERAGE SIZE OF PORES CONTAINED IN A GRADIENT-TYPE POROUS REGION ADJACENT THE INNER PORTION OF SAID RETICULATE POROUS REGION BECOMES SMALLER TOWARD THE INNER SURFACE OF SAID HOLLOW FIBERS; THE AVERAGE SIZE OF PORES IN A GRADIENT TYPE POROUS REGION DECREASING FROM ABOUT 5U - 1U ADJACENT THE RETICULATE POROUS REGION TO ABOUT 0.1 U-SEVERAL A AT A SURFACE OF SAID HOLLOW FIBER.
Claim 6
Dependent Claim
143 words
A GRADIENT-TYPE POROUS REGION ADJACENT TO THE OUTER PORTION OF SAID RETICULATE POROUS REGION OR TO EACH OF THE OUTER AND INNER PORTIONS OF SAID RETICULATE POROUS REGION AND CONCENTRIC WITH THE RETICULATE POROUS REGION AND THE CENTRAL AXIS OF SAID HOLOW FIBER, THE SIZE OF PORES IN THE GRADIENT-TYPE POROUS REGION HAVING A GRADIENT IN THAT THE AVERAGE SIZE OF PORES CONTAINED IN A GRADIENT-TYPE POROUS REGION BECOMES SMALLER TOWARD THE OUTER SURFACE OF SAID HOLLOW FIBERS AND THE AVERAGE SIZE OF PORES CONTAINED IN A GRADIENT-TYPE POROUS REGION ADJACENT THE INNER PORTION OF SAID RETICULATE POROUS REGION BECOMES SMALLER TOWARD THE INNER SURFACE OF SAID HOLLOW FIBERS; THE AVERAGE SIZE OF PORES IN A GRADIENT TYPE POROUS REGION DECREASING FROM ABOUT 5U - 1U ADJACENT THE RETICULATE POROUS REGION TO ABOUT 0.1 U-SEVERAL A AT A SURFACE OF SAID HOLLOW FIBER.
Claim 7
Dependent Claim
24 words
The Hollow fiber of claim 1 wherein the thickness of said gradient-type porous region is from about 1 Mu to about 100 Mu .
Claim 8
Dependent Claim
145 words
a gradient-type porous region adjacent to the outer portion of said reticulate porous region or to each of the outer and inner portions of said reticulate porous region and concentric with the reticulate porous region and the central axis of said hollow fiber, the size of pores in the gradient-type porous region having a gradient in that the average size of pores contained in a gradient-type porous region becomes smaller toward the outer surface of said hollow fibers and the average size of pores contained in a gradient-type porous region adjacent the inner portion of said reticulate porous region becomes smaller toward the inner surface of said hollow fibers; the average size of pores in a gradient type porous region decreasing from about 5 Mu -1 Mu adjacent the reticulate porous region to about 0.1 Mu -several A at a surface of said hollow fiber.
Claim 9
Dependent Claim
145 words
a gradient-type porous region adjacent to the outer portion of said reticulate porous region or to each of the outer and inner portions of said reticulate porous region and concentric with the reticulate porous region and the central axis of said hollow fiber, the size of pores in the gradient-type porous region having a gradient in that the average size of pores contained in a gradient-type porous region becomes smaller toward the outer surface of said hollow fibers and the average size of pores contained in a gradient-type porous region adjacent the inner portion of said reticulate porous region becomes smaller toward the inner surface of said hollow fibers; the average size of pores in a gradient type porous region decreasing from about 5 Mu -1 Mu adjacent the reticulate porous region to about 0.1 Mu -several A at a surface of said hollow fiber.
Claim 10
Dependent Claim
24 words
The hollow fiber of claim 1 wherein the thickness of said gradient-type porous region is from about 10 Mu to about 30 Mu .
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |