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Patent US4575406A successfully refreshed from Google Patents.
US4575406A
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US
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Microporous filter
Assignee: Polaroid Corp
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Filing: 1984-07-23
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Granted: 1986-03-11
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Expires: 2004-07-23
Abstract
Abstract A surface-type metal microporous filter is provided having a substantially uniform pore size of less than 15 micrometers and an open area greater than 10%. Methods for preparing such a filter by electrodeposition techniques are also disclosed.
Inventors
- 👤 Warren D. Slafer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:25
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0039; B01D67/0069; B01D67/0053; B01D67/006; B01D67/0062; B01D71/00; B01D71/02; B01D71/022; C; C25; C25D; C25D1/00; C25D1/08; B01D2325/00; B01D2325/26
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
80 words
A method for forming a metal filter having a pore size of less than 15 micrometers and an open area of greater than 10% which comprises the step of providing a patterned exposure of a photoresist with interferring laser beams; developing said exposed photoresist to provide a substantially planar surface having a relief pattern of depressions therein in said photoresist; rendering said surface electrically conductive, electrically depositing a metal on said electrically conductive surface; and removing the thus-formed metal layer.
Claim 2
Independent Claim
80 words
A method for forming a metal filter having a pore size of less than 15 micrometers and an open area of greater than 10% which comprises the step of providing a patterned exposure of a photoresist with interferring laser beams; developing said exposed photoresist to provide a substantially planar surface having a relief pattern of depressions therein in said photoresist; rendering said surface electrically conductive, electrically depositing a metal on said electrically conductive surface; and removing the thus-formed metal layer.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said electrically conductive substrate comprises a thin metal layer carried on a non-conductive substrate.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein said surface is rendered electrically conductive by evaporating an electrically conductive layer thereon.
Claim 5
Dependent Claim
26 words
The method of claim 3 wherein said evaporation is carried out at an angle of incidence such that substantially no metal is deposited in said depressions.
Claim 6
Dependent Claim
19 words
The method of claim 1 wherein said depressions are filled with a non-electrically conductive material prior to said electrodeposition.
Claim 7
Dependent Claim
16 words
The method of claim 1 which includes laminating said electroformed metal filters to a porous support.
Claim 8
Dependent Claim
22 words
A surface-type metal filter of substantially uniform pore size of less than about 15 micrometers having an open area greater than 10%.
Claim 9
Dependent Claim
22 words
A surface-type metal filter of substantially uniform pore size of less than about 15 micrometers having an open area greater than 10%.
Claim 10
Dependent Claim
17 words
The product of claim 7 wherein said pore size ranges from about 15 to about 0.3 micrometers.
Claim 11
Dependent Claim
12 words
The product of claim 7 wherein said open area is about 50%.
Claim 12
Dependent Claim
10 words
The product of claim 7 which includes a porous support.
Claim 13
Dependent Claim
12 words
The product of claim 7 which includes a uniform distribution of pores.
Claim 14
Dependent Claim
10 words
The product of claim 7 wherein said metal is nickel.
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) | 1989-03-10 | 1989-09-09 | 1990-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-10 | 1993-09-09 | 1994-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-10 | 1997-09-09 | 1998-03-11 | $7700.00 | Window Closed / Lapsed |