Patent US4177228A successfully refreshed from Google Patents.
US4177228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of production of a micro-porous membrane for filtration plants
Assignee: Kilcher-Chemie AG
•
Filing: 1978-06-23
•
Granted: 1979-12-04
•
Expires: 1998-06-23
Abstract
Abstract A method for production of a micro-porous membrane for filtration plants, whereby finely distributed particles are mixed and aligned in a plastics material or a preliminary plastics material product and are insoluble therein, the particles are then dissolved out after reaching the final mould position; said insoluble particles mixed into the plastics material or preliminary plastics material product being aligned in a liquid state in the pores of a coarse pored support membrane at right angles to the membrane surface.
Inventors
- 👤 Ludwig Prolss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:45
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/003; C; C08; C08J; C08J9/00; C08J9/26
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
112 words
A method for production of a micro-porous membrane comprising the steps of: mixing a quantity of finely divided particulate material into a fluid, membrane-forming polymer material; said particulate material being insoluble in said polymer material; forming the particle-containing fluid polymer material into a thin layer and aligning the particles in said layer substantially normal to the surface of said layer while said polymer material is in the fluid state; solidifying said layer containing the aligned particles to form an aligned particle containing membrane; and extracting particles from the aligned particle containing membrane without destroying the membrane to produce a micro-porous membrane having aligned pores substantially normal to the surface of the membrane.
Claim 2
Independent Claim
112 words
A method for production of a micro-porous membrane comprising the steps of: mixing a quantity of finely divided particulate material into a fluid, membrane-forming polymer material; said particulate material being insoluble in said polymer material; forming the particle-containing fluid polymer material into a thin layer and aligning the particles in said layer substantially normal to the surface of said layer while said polymer material is in the fluid state; solidifying said layer containing the aligned particles to form an aligned particle containing membrane; and extracting particles from the aligned particle containing membrane without destroying the membrane to produce a micro-porous membrane having aligned pores substantially normal to the surface of the membrane.
Claim 3
Dependent Claim
63 words
The method of claim 1 wherein the particle containing fluid polymer material is applied to a porous support member by means of a doctor to form the polymer material to a thin layer and align the particles substantially normal to the surface of said layer; the pores of said support member being coarser than the pores to be produced in the microporous membrane.
Claim 4
Dependent Claim
33 words
The method of claim 1 wherein said particles are of magnetic material, and the alignment of said particles is effected by subjecting the magnetic particle containing fluid polymer layer to a magnetic field.
Claim 5
Dependent Claim
31 words
The method of claim 1 wherein said particles are electrically charged and the alignment of the particles is effected by subjecting the charged particle containing polymer layer to an electrostatic field.
Claim 6
Dependent Claim
27 words
The method of claim 1 wherein the particles are pyrolytically obtained particles selected from the group consisting of silicon dioxide, aluminum oxide, titanium oxide and zinc oxide.
Claim 7
Dependent Claim
29 words
The method of claim 2 wherein the magnetic particles are selected from the group consisting of magnetite, iron sulphide, iron oxide, chromite, iron, nickel, chromium oxide and iron-nickle-cobalt alloys.
Claim 8
Dependent Claim
24 words
The method of claim 6 wherein said particles are selected from the group consisting of finely divided iron wire and finely divided nickel wire.
Claim 9
Dependent Claim
13 words
The method of claim 4 wherein said particles comprise finely divided glass fibers.
Claim 10
Dependent Claim
14 words
The method of claim 8 wherein said particles comprise finely divided hollow glass fibers.
Claim 11
Dependent Claim
13 words
The method of claim 4 wherein said particles comprise finely divided quartz particles.
Claim 12
Dependent Claim
30 words
The method of claim 1 wherein said particles are precipitated from aqueous medium and comprise a material selected from the group consisting of aluminum hydroxide, beryllium hydroxide and zirconium hydroxide.
Claim 13
Dependent Claim
20 words
The method of claim 1 wherein said particles have a grain size from about 7 nm to about 50 nm.
Claim 14
Dependent Claim
42 words
The method of claim 1 wherein said polymer material comprises at least one material selected from the group consisting of epoxy resins, acrylic resins, phenolformaldehyde resins, silicon resins, polyester resins, polyvinyl chloride, polyvinylidene fluoride, polyacrylonitrile, polyacrylonitrileopolymers, polyamides, phenoxy resins and polyphenyl sulphones.
Claim 15
Dependent Claim
40 words
The method of claim 1 wherein said particle-containing fluid polymer material is formed into a thin layer on a porous support member, the pores of said support member being coarser than the pores to be produced in the microporous membrane.
Claim 16
Dependent Claim
24 words
The method of claim 1 wherein said extraction is effected by contacting the aligned particle containing membrane with a substance which dissolves the particles.
References Cited (Backward Citations)
US2467214A
Cited
US2474201A
Cited
US2584441A
Cited
GB727679A
Cited
US2983960A
Cited
US2840741A
Cited
US2842799A
Cited
US2887601A
Cited
US3073732A
Cited
US3220960A
Cited
US3507938A
Cited
US3281511A
Cited
US3524768A
Cited
US3642668A
Cited
GB1331775A
Cited
US3700380A
Cited
US3855122A
Cited
US3867299A
Cited
US3836423A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |