US4680040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multipurpose filtering material
Assignee: Xerox Corp
•
Filing: 1986-01-17
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Granted: 1987-07-14
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Expires: 2006-01-17
Abstract
Abstract A multipurpose filtering material particularly for use in electrostatographic reproducing apparatus has a foraminous support matrix having a plurality of interconnecting voids to permit low impedance to the flow of gaseous material but sufficient to trap particulate material entrained in the gaseous material which is coated with a thin dehydrated alkaline film of an alkali metal silicate to neutralize nitrogen oxide species in the gaseous material and has adhesively bound thereto a particulate neutralizer for another noxious gas the surface of which is substantially exposed to the flow of gaseous material. A filter may be placed in electrostatographic reproducing apparatus at the inlet or outlet of an air stream passing therethrough to neutralize nitrogen oxide species and ozone generated by the corona discharge device, and ammonia from the incoming air.
Inventors
- 👤 Arthur M. Gooray
- 👤 George J. Heeks
- 👤 Louis Reale
- 👤 Dipika R. Shah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:10
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2055; B01D39/2058; B01D39/2062; B01D39/2068; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56; G; G03; G03G; G03G21/00; G03G21/20; G03G21/206; B01D2239/00; B01D2239/04; B01D2239/0464; B01D2239/0471; B01D2239/0478; B01D2239/06; B01D2239/065; B01D2239/0654; B01D2239/08; B01D2239/086; B01D2239/12; B01D2239/1216; Y; Y10; Y10S; Y10S55/00; Y10S55/13
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
93 words
A multipurpose filtering material comprising a foraminous support matrix having a plurality of interconnecting voids to permit low impedance to the flow of gaseous material therethrough but sufficient to trap particulate material entrained in the gaseous material, the surface of said support matrix being substantially coated with a thin dehydrated alkaline film of an alkali metal silicate to neutralize nitrogen oxide species in the gaseous material, and having ahesively bound thereto a particulate neutralizer for another noxious gas, the surface of said particulate neutralizer being substantially exposed to the flow of gaseous material.
Claim 2
Dependent Claim
93 words
A multipurpose filtering material comprising a foraminous support matrix having a plurality of interconnecting voids to permit low impedance to the flow of gaseous material therethrough but sufficient to trap particulate material entrained in the gaseous material, the surface of said support matrix being substantially coated with a thin dehydrated alkaline film of an alkali metal silicate to neutralize nitrogen oxide species in the gaseous material, and having ahesively bound thereto a particulate neutralizer for another noxious gas, the surface of said particulate neutralizer being substantially exposed to the flow of gaseous material.
Claim 3
Dependent Claim
17 words
The filtering material of claim 1 wherein said foraminous support matrix is a reticulated open cell foam.
Claim 4
Dependent Claim
15 words
The filtering material of claim 1 wherein said foraminous support matrix is a fibrous material.
Claim 5
Dependent Claim
59 words
The filtering material of claim 1 wherein said dehydrated alkaline film is the dehydrated product of an aqueous sodium silicate solution having a silica to oxide weight ratio of from about 1.6 to about 3.75, density of from about 35° Be to about 60° Be at 20° C. and a viscosity of from about 200 to about 800 centipoises.
Claim 6
Dependent Claim
15 words
The filtering material of claim 4 wherein said silica to oxide ratio is about 2.
Claim 7
Dependent Claim
59 words
The filtering material of claim 1 wherein said dehydrated alkaline film is the dehydrated product of an aqueous potassium silicate solution having a silica to oxide weight ratio of from about 2.1 to 2.5, a density of from about 30° Be to about 40° Be at 20° C. and a viscosity of from about 7 to about 1050 centipoises.
Claim 8
Dependent Claim
13 words
The filtering material of claim 1 wherein said particulate neutralizer is activated carbon.
Claim 9
Dependent Claim
12 words
The filtering material of claim 1 wherein said particulate neutralizer is Hopcalite.
Claim 10
Dependent Claim
24 words
The filtering material of claim 1 wherein said foraminous material has a pore size of from about 4 to 40 pores per linear centimeter.
Claim 11
Dependent Claim
25 words
The filtering material of claim 1 wherein said particulate neutralizer has a surface area of from about 300 to about 1500 square meters per gram.
Claim 12
Dependent Claim
21 words
The filtering material of claim 1 wherein said dehydrated alkaline film of an alkali metal silicate adhesively binds said particulate neutralizer.
Claim 13
Dependent Claim
59 words
A method of making the multipurpose filtering material of claim 1 comprising providing said foraminous support matrix, coating said matrix with an aqueous solution of an alkali metal silicate and before said aqueous solution has dehydrated contacting said coated support matrix with the particulate neutralizer and drying said filter material to bind said particulate neutralizer to said support matrix.
Claim 14
Dependent Claim
32 words
The method of claim 11 wherein said foraminous support matrix is coated with the aqueous solution of an alkali metal silicate by immersing said matrix in a bath of said aqueous solution.
Claim 15
Dependent Claim
21 words
The method of claim 12 wherein said coated support matrix is contacted with said particulate neutralizer by mixing in a container.
Claim 16
Dependent Claim
124 words
In an imaging apparatus including at least one corona discharge electrode, means for circulation of an air stream into, through and out of said apparatus, said air stream being directed through a multipurpose filtering material comprising; a foraminous support matrix having a plurality of interconnecting voids to permit low impedance to the flow of gaseous material therethrough but sufficient to trap particulate material entrained in the gaseous material, the surface of said support matrix being substantially coated with a thin dehydrated alkaline film of an alkali metal silicate to neutralize nitrogen oxide species in the gaseous material, and having adhesively bound thereto a particulate neutralizer for another noxious gas, the surface of said particulate neutralizer begin substantially exposed to the flow of gaseous material.
Claim 17
Dependent Claim
124 words
In an imaging apparatus including at least one corona discharge electrode, means for circulation of an air stream into, through and out of said apparatus, said air stream being directed through a multipurpose filtering material comprising; a foraminous support matrix having a plurality of interconnecting voids to permit low impedance to the flow of gaseous material therethrough but sufficient to trap particulate material entrained in the gaseous material, the surface of said support matrix being substantially coated with a thin dehydrated alkaline film of an alkali metal silicate to neutralize nitrogen oxide species in the gaseous material, and having adhesively bound thereto a particulate neutralizer for another noxious gas, the surface of said particulate neutralizer begin substantially exposed to the flow of gaseous material.
Claim 18
Dependent Claim
16 words
The apparatus of claim 15 wherein said foraminous support matrix is a reticulated open cell foam.
Claim 19
Dependent Claim
16 words
The apparatus of claim 15 wherein said foraminous support matrix is a high loft fibrous material.
Claim 20
Dependent Claim
58 words
The apparatus of claim 15 wherein said dehydrated alkaline film is the dehydrated product of an aqueous sodium silicate solution having a silica to oxide weight ratio of from about 1.6 to about 3.75, density of from about 35° Be to about 60° Be at 20° C. and a viscosity of from about 200 to about 800 centipoises.
Claim 21
Dependent Claim
14 words
The apparatus of claim 17 wherein said silica to oxide ratio is about 2.
Claim 22
Dependent Claim
58 words
The apparatus of claim 17 wherein said dehydrated alkaline film is the dehydrated product of an aqueous potassium silicate solution having a silica to oxide weight ratio of from about 2.1 to 2.5, a density of from about 30° Be to about 40° Be at 20° C. and a viscosity of from about 7 to about 1050 centipoises.
Claim 23
Dependent Claim
11 words
The apparatus of claim 17 said particulate neutralizer is activated carbon.
Claim 24
Dependent Claim
11 words
The apparatus of claim 17 wherein said particulate neutralizer is Hopcalite.
Claim 25
Dependent Claim
23 words
The apparatus of claim 17 wherein said foraminous material has a pore size of from about 4 to 40 pores per linear centimeter.
Claim 26
Dependent Claim
20 words
The apparatus of claim 17 wherein said particulate neutralizer has a surface area of from about 300 to about 1500.
Claim 27
Dependent Claim
20 words
The apparatus of claim 17 wherein said dehydrated alkaline film of an alkali metal silicate adhesively binds said particulate neutralizer.
Claim 28
Dependent Claim
18 words
The apparatus of claim 15 wherein said filtering material is positioned at the inlet of said air stream.
Claim 29
Dependent Claim
18 words
The apparatus of claim 15 wherein said filtering material is positioned at the outlet of said air stream.
Claim 30
Dependent Claim
14 words
The apparatus of claim 15 wherein said imaging apparatus comprises an electrostatographic reproducing apparatus.
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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) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |