US4666607A
Expired / Lapsed
US
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Porous shaped bodies, and method and apparatus for the production thereof
Assignee: Akzo NV
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Filing: 1984-07-23
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Granted: 1987-05-19
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Expires: 2004-07-23
Abstract
Abstract Porous shaped bodies are disclosed, and an apparatus and method of their production by extruding a homogeneous, single-phase liquid mixture of polymer and mixing partner liquid at the temperature of mixture preparation through a nozzle downwardly with a linear velocity v 1 into a cooling liquid that dissolves the polymer insubstantially or not at all at the cooling temperature, the cooling liquid being provided from entry of the extruded mixture until at least the point of start of solidification thereof in a substantially vertically arranged tubular zone surrounded by a wall, velocity v 2 of cooling liquid in this zone being less than v 1 . The cooling liquid is preferably contained in a U-shaped tube and its level is controllable by dosing at entry and/or exit points.
Inventors
- 👤 Christoph Josefiak
- 👤 Friedrich Wechs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:31
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/08; B01D63/00; B01D63/06; B01D63/061; B01D71/00; B01D71/06; B01D71/30; B01D71/32; B01D71/34; B01D71/56; B01D71/72; B29; B29C; B29C48/00; B29C48/022; B29C48/03; B29C48/05; B29C48/07; B29C48/08; B29C48/09; B29C48/10; B29C48/25; B29C48/88; B29C48/911; B29K; B29K2027/00; B29K2027/12; B29K2077/00; B29K2105/00; B29K2105/0058; B29K2105/0073; B29K2105/04; B29K2105/045; B29L; B29L2031/00; B29L2031/14
Claims Analysis
Total Claims: 52
Claim 1
Independent Claim
362 words
A method for the production of a porous shaped body comprising the steps of: (a) extruding a homogeneous signal phase liquid mixture of at least one meltable organic polymer and at least one inert mixing partner, liquid at the temperature of preparation of said mixture, and wherein at least one liquid mixing partner is a solvent for the meltable organic polymer at the temperature of the preparation of the mixture, said mixture displaying in a liquid state and above room temperature a range of complete miscibility, a range with a miscibility gap, and a solidification range, at a temperature above said miscibility gap; (b) leading said extruded mixture at an average linear velocity V 1 from its entry point into a cooling liquid having a temperature below the solidification point of said meltable organic polymer within said mixture, said cooling liquid dissolving said meltable organic polymer insubstantially or not at all at said temperature at least until said meltable organic polymer begins to solidify, initially through a substantially vertically arranged tubular first zone, surrounded by walls, and filled with said cooling liquid, wherein the average linear velocity V 2 of said cooling liquid to said substantially vertically arranged tubular first zone, measured in the direction of movement of said polymer-mixing partner mixture is at least 20% less than the velocity V 1 of the extruded mixture to minimize mechanical stress on said mixture to convert said homogeneous single phase mixture to two liquid phases occuring side-by-side as a result of separating in the liquid state a polymer-poor liquid phase of the mixing partner and a mixing partner-poor, polymer-enriched liquid phase, whereby upon further cooling the mixing partner-poor, polymer-enriched liquid phase forms a porous shaped body; (c) guiding said porous shaped body formed after the start of solidification of the meltable organic polymer and leading said porous shaped body upwardly through a second zone of said cooling liquid; (d) withdrawing the porous shaped body from said second zone of said cooling liquid; and (e) maintaining constant the level of said cooling liquid not only at the entry point but also at the exit point of said porous shaped body from said cooling liquid.
Claim 2
Independent Claim
362 words
A method for the production of a porous shaped body comprising the steps of: (a) extruding a homogeneous signal phase liquid mixture of at least one meltable organic polymer and at least one inert mixing partner, liquid at the temperature of preparation of said mixture, and wherein at least one liquid mixing partner is a solvent for the meltable organic polymer at the temperature of the preparation of the mixture, said mixture displaying in a liquid state and above room temperature a range of complete miscibility, a range with a miscibility gap, and a solidification range, at a temperature above said miscibility gap; (b) leading said extruded mixture at an average linear velocity V 1 from its entry point into a cooling liquid having a temperature below the solidification point of said meltable organic polymer within said mixture, said cooling liquid dissolving said meltable organic polymer insubstantially or not at all at said temperature at least until said meltable organic polymer begins to solidify, initially through a substantially vertically arranged tubular first zone, surrounded by walls, and filled with said cooling liquid, wherein the average linear velocity V 2 of said cooling liquid to said substantially vertically arranged tubular first zone, measured in the direction of movement of said polymer-mixing partner mixture is at least 20% less than the velocity V 1 of the extruded mixture to minimize mechanical stress on said mixture to convert said homogeneous single phase mixture to two liquid phases occuring side-by-side as a result of separating in the liquid state a polymer-poor liquid phase of the mixing partner and a mixing partner-poor, polymer-enriched liquid phase, whereby upon further cooling the mixing partner-poor, polymer-enriched liquid phase forms a porous shaped body; (c) guiding said porous shaped body formed after the start of solidification of the meltable organic polymer and leading said porous shaped body upwardly through a second zone of said cooling liquid; (d) withdrawing the porous shaped body from said second zone of said cooling liquid; and (e) maintaining constant the level of said cooling liquid not only at the entry point but also at the exit point of said porous shaped body from said cooling liquid.
Claim 3
Dependent Claim
35 words
The method according to claim 1, further comprising after withdrawing said porous shaped body from said cooling liquid washing until all components aside from said polymer are completely or nearly completely removed, and then drying.
Claim 4
Dependent Claim
36 words
The method according to claim 1, wherein said cooling liquid is led through said substantially vertically arranged tubular first zone with an average linear velocity v 2 at least about 25% less than v 1 .
Claim 5
Dependent Claim
20 words
The method according to claim 1, wherein said average linear velocity v 2 of said cooling liquid substantially equals 0.
Claim 6
Dependent Claim
43 words
The method according to claim 1, wherein a liquid reflecting surface of said cooling liquid at an exit point for said porous shaped body is maintained at the same level as at an entry point of said polymer/mixing partner-mixture into said cooling liquid.
Claim 7
Dependent Claim
21 words
The method according to claim 1, wherein said cooling liquid comprises a cooling liquid bath situated in a U-shaped curved tube.
Claim 8
Dependent Claim
62 words
The method according to claim 1, further comprising continuously dosing supplementary cooling liquid into said cooling liquid close to said entry point of said mixture into said cooling liquid so that it flows parallel with a direction of movement of said mixture and then leaves said cooling arrangement means at an exit point of said porous shaped body from said cooling liquid.
Claim 9
Dependent Claim
29 words
The method according to claim 1, wherein said cooling liquid is supplied through a plurality of openings arranged about an entry point of said mixture into said cooling liquid.
Claim 10
Dependent Claim
23 words
The method according to claim 8, wherein said cooling liquid is supplied through openings symmetrically disposed about said entry point of said mixture.
Claim 11
Dependent Claim
30 words
The method according to claim 7, wherein said cooling liquid is dosed in the form of a coherent film around an entry point of said mixture into said cooling liquid.
Claim 12
Dependent Claim
32 words
The method according to claim 1, wherein said step of extruding is effected over an airgap defined between said nozzle and said entry point of said polymer/mixing partner-mixture into said cooling liquid.
Claim 13
Dependent Claim
17 words
The method according to claim 11, wherein said air-gap has a length between 2 and 20 mm.
Claim 14
Dependent Claim
17 words
The method defined in claim 11, wherein the temperature and humidity of the airgap are maintained constant.
Claim 15
Dependent Claim
35 words
The method according to claim 1, wherein said cooling liquid possesses at said entry point of said mixture into said cooling liquid a specific weight up to 20% lower than said mixture at this place.
Claim 16
Dependent Claim
20 words
The method according to claim 1, comprising extruding a polymer/mixing partner-mixture having a viscosity between 2 and 25 Pa s.
Claim 17
Dependent Claim
18 words
The method according to claim 1, comprising extruding a polymer/mixing partner-mixture containing 10 to 90% by weight polymer.
Claim 18
Dependent Claim
18 words
The method according to claim 1, comprising extruding a polymer/mixing partner-mixture containing 10 to 25% by weight polymer.
Claim 19
Dependent Claim
25 words
The method according to claim 1, wherein said polymer/mixing partner-mixture is deformed into a membrane in the shape of a hollow fiber, tubing or foil.
Claim 20
Dependent Claim
45 words
The method according to claim 18, for the production of hollow fibers or tubing, wherein a lumen inside said porous shaped body is formed by means of introducing a liquid, said liquid constituting at the temperature of forming said lumen a non-solvent for said polymer.
Claim 21
Dependent Claim
23 words
The method according to claim 19, wherein said liquid comprises glycerin or a liquid employed as mixing partner for preparation of said mixture.
Claim 22
Dependent Claim
38 words
The method according to claim 18, for the production of hollow fibers or tubing, further comprising providing a lumen inside said porous shaped body by means of introducing gaseous nitrogen through an interior of said porous shaped body.
Claim 23
Dependent Claim
18 words
The method according to claim 1, wherein the solidification temperature of said mixture lies above about 50° C.
Claim 24
Dependent Claim
21 words
The method according to claim 1, wherein water is employed as said cooling liquid, with or without addition of a surfactant.
Claim 25
Dependent Claim
19 words
The method according to claim 23, employing water as cooling liquid having a temperature between 20° and 80° C.
Claim 26
Dependent Claim
42 words
The method according to claim 1, wherein said mixture comprises in addition to at least one solvent at least one mixing partner which is a non-solvent for said polymer at temperature of production of said mixture and its extrusion through said nozzle.
Claim 27
Dependent Claim
12 words
The method according to claim 1, wherein Polyamide is employed as polymer.
Claim 28
Dependent Claim
17 words
The method according to claim 1, employing as polymer copolyamide based upon E-caprolactam and hexamethylenediamine/adipic acid salt.
Claim 29
Dependent Claim
16 words
The method according to claim 26, employing as mixing partner a mixture of ethyleneglycol and glycerin.
Claim 30
Dependent Claim
12 words
The method according to claim 1, employing as polymer polyvinylidene fluoride (PVDF).
Claim 31
Dependent Claim
30 words
The method according to claim 29, employing as solvent for production of said mixture at least one compound selected from the group consisting of glycerin triacetate, glycerin diacetate and 2-(2-butoxyethoxy)-ethylacetate.
Claim 32
Dependent Claim
27 words
The method according to claim 29, further comprising employment of di-n-octyladipate or castor oil or a mixture thereof as non-solvent for PVDF while producing said polymer/mixing partner-mixture.
Claim 33
Dependent Claim
26 words
The method according to claim 30, further comprising employing di-n-octyladipate or castor oil or a mixture thereof as non-solvent for PVDF while producing said polymer/mixing partner-mixture.
Claim 34
Dependent Claim
20 words
The method according to claim 1, wherein said mixture further comprises 0.05 up to 0.3% by weight of thickening means.
Claim 35
Dependent Claim
31 words
The method according to claim 1, wherein said cooling liquid is led through the substantially vertically arranged tubular first zone opposite to the direction of movement of the polymer/mixing partner mixture.
Claim 36
Dependent Claim
13 words
A porous shaped body produced according to the process defined in claim 15.
Claim 37
Dependent Claim
11 words
Porous shaped body produced according to the method of claim 29.
Claim 38
Dependent Claim
13 words
The porous shaped body according to claim 36, containing an anisotropic pore system.
Claim 39
Dependent Claim
33 words
A method of microfiltering a strongly acid or alkaline aqueous solution which comprises the step of passing said solution through a porous membrane prepared from the porous shaped body defined in claim 36.
Claim 40
Dependent Claim
30 words
A method of microfiltering an oxidizing solution medium which comprises the step of passing said solution through a porous membrane prepared from the porous shaped body defined in claim 36.
Claim 41
Dependent Claim
30 words
A method of microfiltering an aqueous hypochlorite solution which comprises the step of passing said solution through a porous membrane prepared from the porous shaped body defined in claim 36.
Claim 42
Dependent Claim
26 words
A method of carrying out transmembrane distillation which comprises the step of employing a porous membrane prepared from the porous shaped body defined in claim 36.
Claim 43
Dependent Claim
139 words
An extrusion apparatus for the production of a porous shaped body from a homogeneous single-phase liquid mixture which comprises: (a) a nozzle for extruding the homogeneous single-phase liquid mixture downardly; (b) cooling means, for containing a cooling liquid, said cooling means having a substantially vertically arranged tubular zone communicating with said nozzle and surrounded by wall means reaching from an entry point of said mixture downwardly until at least a point of commencing solidification of said mixture, said cooling means having directing means below a point of commencing solidification to upwardly guide the solidified mixture along a U-shaped path, as well as at least one opening for supply and exit of the cooling liquid; and (c) offtake means for said porous shaped body, said offtake means disposed separately from said cooling means at the end of said U-shaped path.
Claim 44
Dependent Claim
139 words
An extrusion apparatus for the production of a porous shaped body from a homogeneous single-phase liquid mixture which comprises: (a) a nozzle for extruding the homogeneous single-phase liquid mixture downardly; (b) cooling means, for containing a cooling liquid, said cooling means having a substantially vertically arranged tubular zone communicating with said nozzle and surrounded by wall means reaching from an entry point of said mixture downwardly until at least a point of commencing solidification of said mixture, said cooling means having directing means below a point of commencing solidification to upwardly guide the solidified mixture along a U-shaped path, as well as at least one opening for supply and exit of the cooling liquid; and (c) offtake means for said porous shaped body, said offtake means disposed separately from said cooling means at the end of said U-shaped path.
Claim 45
Dependent Claim
13 words
The apparatus according to claim 42, wherein said cooling means comprise a U-tube.
Claim 46
Dependent Claim
13 words
The apparatus according to claim 43, wherein said U-tube is an equal-leg U-tube.
Claim 47
Dependent Claim
20 words
The apparatus according to claim 42, comprising inlet means having a plurality of symmetrically disposed openings for said cooling liquid.
Claim 48
Dependent Claim
16 words
The apparatus according to claim 42, further comprising overflow means for dosing of said cooling liquid.
Claim 49
Dependent Claim
16 words
The apparatus according to claim 42, further comprising overflow means for runoff of said cooling liquid.
Claim 50
Dependent Claim
11 words
The apparatus according to claim 42, further comprising external thermostatization means.
Claim 51
Dependent Claim
28 words
The apparatus according to claim 42, wherein said nozzle and a level of cooling liquid at an entry point of said mixture are separated by an air gap.
Claim 52
Dependent Claim
18 words
The apparatus according to claim 42, wherein said cooling means are box-shaped and further comprise a sight opening.
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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) | 1990-05-18 | 1990-11-17 | 1991-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-18 | 1994-11-17 | 1995-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-18 | 1998-11-17 | 1999-05-19 | $7700.00 | Window Closed / Lapsed |