US4990544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gasket composition comprising fibrillated PTFE
Assignee: Nichias Corp
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Filing: 1989-05-01
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Granted: 1991-02-05
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Expires: 2009-05-01
Abstract
Abstract Use of a composition comprising a polytetrafluoroethylene resin and a fine inorganic powder for a gasket, said composition being characterized in that the polytetrafluoroethylene resin is at least 5% by weight and the fine inorganic powder is at least 40% by weight, based on the total amount of the polytetrafluoroethylene resin and the fine inorganic powder; the total amount of the polytetrafluoroethylene resin and the fine inorganic powder is at least 80% by weight based on the entire amount of the composition; and the polytetrafluoroethylene resin and the fine inorganic powder are mutually uniformly dispersed and mixed with each other.
Inventors
- 👤 Hiroshi Asaumi
- 👤 Zenji Shimura
- 👤 Takehiro Yoshida
- 👤 Kenji Tadakuma
- 👤 Shinzaburo Suzuki
- 👤 Norio Takada
- 👤 Kenichi Nakamura
- 👤 Takene Hirai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:07
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/02; F16J15/06; F16J15/10; F16J15/12; F16J15/121; F16J15/122; Y; Y10; Y10S; Y10S277/00; Y10S277/935; Y10S277/936; Y10S277/938; Y10S277/944; Y10S277/945; Y10S277/946; Y10T; Y10T428/00; Y10T428/25; Y10T428/252; Y10T428/31504; Y10T428/3154; Y10T428/31544; Y10T428/31678; Y10T428/31692; Y10T428/31699; Y10T428/31707; Y10T442/00; Y10T442/60; Y10T442/654; Y10T442/656; Y10T442/699
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
143 words
A gasket of a composition comprising a fibrillated polytetrafluoroethylene resin and a fine inorganic powder having an average particle size of not larger than 100 μm and containing at least 30% by weight of a clay mineral, based on the total weight of the inorganic powder, said composition being characterized in that the polytetrafluoroethylene resin is at least 5% by weight and the fine inorganic powder is at least 40% by weight, based on the total amount of the polytetrafluoroethylene resin and the fine inorganic powder; the total amount of the polytetrafluoroethylene resin and the fine inorganic powder is at least 80% by weight based on the entire amount of the composition; and the fibrillated polytetrafluoroethylene resin and the fine inorganic powder are mutually uniformly dispersed and mixed with each other, said composition having an average pore size not larger than 0.15 μm.
Claim 2
Dependent Claim
143 words
A gasket of a composition comprising a fibrillated polytetrafluoroethylene resin and a fine inorganic powder having an average particle size of not larger than 100 μm and containing at least 30% by weight of a clay mineral, based on the total weight of the inorganic powder, said composition being characterized in that the polytetrafluoroethylene resin is at least 5% by weight and the fine inorganic powder is at least 40% by weight, based on the total amount of the polytetrafluoroethylene resin and the fine inorganic powder; the total amount of the polytetrafluoroethylene resin and the fine inorganic powder is at least 80% by weight based on the entire amount of the composition; and the fibrillated polytetrafluoroethylene resin and the fine inorganic powder are mutually uniformly dispersed and mixed with each other, said composition having an average pore size not larger than 0.15 μm.
Claim 3
Dependent Claim
13 words
The gasket according to claim 1, wherein the clay mineral is kaolinite clay.
Claim 4
Dependent Claim
29 words
The gasket according to claim 1, wherein the composition contains not more than 10% by weight of an inorganic fiber powder based on the entire amount of the composition.
Claim 5
Dependent Claim
30 words
The use according to claim 1, wherein the composition contains not more than 10% by weight of a heat resistant synthetic resin based on the entire amount of the composition.
Claim 6
Dependent Claim
12 words
The gasket according to claim 1, wherein the polytetrafluoroethylene resin is sintered.
Claim 7
Dependent Claim
13 words
The gasket according to claim 1, wherein the polytetrafluoroethylene resin is not sintered.
Claim 8
Dependent Claim
16 words
The gasket according to claim 1, wherein the clay mineral is kaolinite, halloysite or hydrated halloysite.
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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) | 1994-02-04 | 1994-08-06 | 1995-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-04 | 1998-08-06 | 1999-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-04 | 2002-08-06 | 2003-02-05 | $7700.00 | Window Closed / Lapsed |