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US4604326A
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Porous regenerated cellulose hollow fiber and process for preparation thereof
Assignee: Asahi Kasei Corp
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Filing: 1984-04-27
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Granted: 1986-08-05
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Expires: 2004-04-27
Abstract
Abstract A porous regenerated cellulose hollow fiber obtained by a micro-phase-separation method is described. The hollow fiber is characterized in that the viscosity average molecular weight is at least 5×10 4 , each of the average pore diameter D 1 on the inner wall surface of the hollow fiber and the average pore diameter D 2 on the outer wall surface is 0.02 to 10 μm, the in-plane porosity Pr on the outer wall surface is at least 10%, and the hollow fiber comprises a wall thickness portion having pores piercing therethrough between the inner wall surface and outer wall surface and a hollow portion extending continuously over the entire fiber length. The hollow fiber is prepared by a process characterized in that at the steps of extruding a cuprammonium solution of a cellulose from an annular spinning orifice and coagulating, regenerating and water-washing the extrudate, the spinning solution is extruded from an outer annular spinning orifice and a liquid having a coagulating action to the spinning solution is extruded from a central spinning orifice, and micro-phase-separation is caused to occur before the coagulation.
Inventors
- 👤 Seiichi Manabe
- 👤 Michitaka Iwata
- 👤 Mamoru Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:03
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/08; B01D71/10; B01D69/00; B01D69/08; B01D69/087; B01D69/0871; D; D01; D01F; D01F2/00; D01F2/02; D01F2/04; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2935; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
202 words
A porous regenerated cellulose hollow fiber characterized by an inner wall surface, an outer wall surface, a hollow portion extending continuously over the entire fiber length, and a wall thickness portion having pores piercing therethrough between said inner wall surface and outer wall surface , said hollow fiber having about 10 5 to about 10 9 of fine particles and agglomerates thereof per cm 2 of said hollow fiber area wherein said fine particles have a diameter of 0.02 to 1 μm, the cellulose molecules of said fiber having a viscosity average molecular weight of at least 5×10 4 , said pores having an average pore diameter D 1 and an in-plane porosity Pr on the inner wall surface of said hollow fiber, an average pore diameter D 2 and an in-plane porosity Pr on the outer wall surface of said hollow fiber and an average pore diameter D 3 and an in-plane porosity Pr of the intermediate part of said wall thickness portion, each of the average pore diameters D 1 and D 2 being in the range of 0.02 to 10 μm and the in-plane porosity Pr on the outer wall surface of the hollow fiber being at least 10%.
Claim 2
Dependent Claim
202 words
A porous regenerated cellulose hollow fiber characterized by an inner wall surface, an outer wall surface, a hollow portion extending continuously over the entire fiber length, and a wall thickness portion having pores piercing therethrough between said inner wall surface and outer wall surface , said hollow fiber having about 10 5 to about 10 9 of fine particles and agglomerates thereof per cm 2 of said hollow fiber area wherein said fine particles have a diameter of 0.02 to 1 μm, the cellulose molecules of said fiber having a viscosity average molecular weight of at least 5×10 4 , said pores having an average pore diameter D 1 and an in-plane porosity Pr on the inner wall surface of said hollow fiber, an average pore diameter D 2 and an in-plane porosity Pr on the outer wall surface of said hollow fiber and an average pore diameter D 3 and an in-plane porosity Pr of the intermediate part of said wall thickness portion, each of the average pore diameters D 1 and D 2 being in the range of 0.02 to 10 μm and the in-plane porosity Pr on the outer wall surface of the hollow fiber being at least 10%.
Claim 3
Dependent Claim
62 words
The regenerated cellulose hollow fiber as set forth in claim 1 which further satisfies the requirement represented by the formula: ##EQU3## wherein Prρ stands for an average porosity in the entire wall thickness portion, d stands for the wall thickness (μm), r 3 stands for a tertiary average pore radium (μm), and r 4 stands for the quaternary average pore radius (μm).
Claim 4
Dependent Claim
72 words
The regenerated cellulose hollow fiber as set forth in claim 2, wherein the ratio (D 1 /D 2 ) is in the range of 0.5≦D 1 /D 2 ≦50, the ratio (D 3 /D 2 ) is in the range of from 0.2≦D 3 /D 2 ≦10the in-plane porosity Pr of the intermediate part of said wall thickness portion is at least 10%, and the average porosity (Prρ) is at least 40%.
Claim 5
Dependent Claim
61 words
The regenerated cellulose hollow fiber as set forth in claim 1, 2 or 3, further characterized by a crystal region, wherein said crystal region of the hollow fiber consists of a crystal of cellulose II, cellulose III-2 or a mixture thereof and the orientation parameter of the plane (101) to the radial direction of the hollow fiber is smaller than 0.3.
Claim 6
Dependent Claim
56 words
The regenerated cellulose hollow fiber as set forth in claim 4, wherein the dynamic elastic modulus of the hollow fiber as measured at 30° C. at a frequency of 110 Hz is at least 1.5×10 8 (100-Prρ) dyn/cm 2 and the peak temperature (Tmax) of the dynamic loss tangent (tan δ) is at least 250° C.
Claim 7
Dependent Claim
23 words
The regenerated cellulose hollow fiber as set forth in claim 3, wherein the average pore diameter D 3 is at least 0.2 μm.
Claim 8
Dependent Claim
109 words
The regenerated cellulose hollow fiber as set forth in claim 1, 2 or 3, wherein the viscosity average molecular weight of cellulose molecules of said fiber is 5.75×10 4 , the dynamic elastic modulus of the hollow fiber is 1.3×10 10 dyn/cm 2 as measured at 30° C. at a frequency of 110 Hz, the peak value (tan δ max) of the dynamic loss tangent tan δ is 0.14, the peak temperature Tmax of tan δ is 262° C., the average pore diameter of the outer wall surface is 1 μm, the average pore diameter of the inner wall surface is 1.2 μm, and the average porosity is 72%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-04 | 1990-02-03 | 1990-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-04 | 1994-02-03 | 1994-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-04 | 1998-02-03 | 1998-08-05 | $7700.00 | Window Closed / Lapsed |