Patent US4680221A successfully refreshed from Google Patents.
US4680221A
Expired / Lapsed
US
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Chemical-resistant filter material
Assignee: Teijin Ltd
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Filing: 1985-12-23
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Granted: 1987-07-14
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Expires: 2005-12-23
Abstract
Abstract Disclosed is a chemical resistant filter material made of a fibrous structure, the fiber surface of which is coated with at least one inorganic oxide selected from oxides of silicon, aluminum and lithium, and an optional fluoropolymer resin.
Inventors
- 👤 Sadamitsu Murayama
- 👤 Makoto Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:42
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/16; B01D39/1607; B01D39/1623; B01D2239/00; B01D2239/04; B01D2239/0471; B01D2239/0478; B01D2239/12; B01D2239/1291; Y; Y10; Y10S; Y10S428/00; Y10S428/92; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154; Y10T428/31544; Y10T428/31725; Y10T428/31765; Y10T442/00; Y10T442/20; Y10T442/2549; Y10T442/2631; Y10T442/2713
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
38 words
A chemical resist filter material comprising a fibrous structure made of organic fibers, the fiber surface of which is coated with at least one inorganic oxide selected from the group consisting of oxides of silicon, aluminum and lithium.
Claim 2
Dependent Claim
38 words
A chemical resist filter material comprising a fibrous structure made of organic fibers, the fiber surface of which is coated with at least one inorganic oxide selected from the group consisting of oxides of silicon, aluminum and lithium.
Claim 3
Dependent Claim
19 words
A chemical-resistant filter material according to claim 1, wherein the fibrous structure is made of an aromatic polyamide fiber.
Claim 4
Dependent Claim
18 words
A chemical-resistant filter material according to claim 2, wherein the aromatic polyamide fiber is a polymetaphenylene isophthalamide fiber.
Claim 5
Dependent Claim
40 words
A chemical-resistant filter material according to claim 1, wherein the amount of the inorganic oxide deposited on the fibrous structure is in the range of 2 to 40% by weight as solid based on the weight of the fibrous structure.
Claim 6
Dependent Claim
25 words
A chemical-resistant filter material according to claim 1, wherein the inorganic oxide applied to the fibrous structure is in the form of a colloidal solution.
Claim 7
Dependent Claim
14 words
A chemical-resistant filter material according to claim 1, wherein the inorganic oxide is alumina.
Claim 8
Dependent Claim
37 words
A chemical-resistant filter material comprising a fibrous structure, the fiber surface of which is coated with at least one inorganic oxide selected from the group consisting of oxides of silicon, aluminum and lithium, and a fluoropolymer resin.
Claim 9
Dependent Claim
37 words
A chemical-resistant filter material comprising a fibrous structure, the fiber surface of which is coated with at least one inorganic oxide selected from the group consisting of oxides of silicon, aluminum and lithium, and a fluoropolymer resin.
Claim 10
Dependent Claim
19 words
A chemical-resistant filter material according to claim 7, wherein the fibrous structure is made of an aromatic polyamide fiber.
Claim 11
Dependent Claim
18 words
A chemical-resistant filter material according to claim 7, wherein the aromatic polyamide fiber is a polymetaphenylene isophthalamide fiber.
Claim 12
Dependent Claim
40 words
A chemical-resistant fiber material according to claim 7, wherein the amount of the inorganic oxide deposited on the fibrous structure is in the range of 2 to 40% by weight as solid based on the weight of the fibrous structure.
Claim 13
Dependent Claim
25 words
A chemical-resistant filter material according to claim 7, wherein the inorganic oxide applied to the fibrous structure is in the form of a colloidal solution.
Claim 14
Dependent Claim
14 words
A chemical-resistant fiber material according to claim 7, wherein the inorganic oxide is alumina.
Claim 15
Dependent Claim
40 words
A chemical-resistant filter material according to claim 7, wherein the amount of the fluoropolymer resin deposited on the fibrous structure is in the range of 0.1 to 20% by weight as solid based on the weight of the fibrous structure.
Claim 16
Dependent Claim
26 words
A chemical-resistant filter material according to claim 7, wherein the fluoropolymer resin is a polymer having fluorine atoms bonded to the main chain of carbon atoms.
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) | 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 |