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US4456648A
Expired / Lapsed
US
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Particulate-modified electret fibers
Assignee: 3M Co
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Filing: 1983-09-09
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Granted: 1984-06-26
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Expires: 2003-09-09
Abstract
Abstract Fibrous web electrets are given added properties through inclusion of a particulate material, such as a flame-retardant agent, in less than all the layers of a plural-layer film from which fibers are fibrillated, and by use of a brominated derivative of bisphenol A as the flame-retardant agent.
Inventors
- 👤 Jan W. C. Adamse
- 👤 Jan van Turnhout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:34
CPC Classifications
H; H01; H01G; H01G7/00; H01G7/02; H01G7/021; H01G7/023; Y; Y10; Y10S; Y10S428/00; Y10S428/92; Y10S428/921; Y10S55/00; Y10S55/39; Y10T; Y10T442/00; Y10T442/60; Y10T442/637; Y10T442/642; Y10T442/696; Y10T442/699
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
76 words
A modified fibrous web electret comprising fibers fibrillated from a film comprising two or more layers that comprise nonpolar polymeric material, one of said layers being substantially free of particulate matter, and another layer including particulate material which can potentially increase the conductivity of the layer, said particulate material having an average diameter smaller than the thickness of the layer, and said web maintaining a high charge level even when kept in a high humidity environment.
Claim 2
Dependent Claim
76 words
A modified fibrous web electret comprising fibers fibrillated from a film comprising two or more layers that comprise nonpolar polymeric material, one of said layers being substantially free of particulate matter, and another layer including particulate material which can potentially increase the conductivity of the layer, said particulate material having an average diameter smaller than the thickness of the layer, and said web maintaining a high charge level even when kept in a high humidity environment.
Claim 3
Dependent Claim
12 words
A fibrous web of claim 1 in which said layers comprise polypropylene.
Claim 4
Dependent Claim
23 words
A fibrous web of claim 1 in which said included particulate material comprises an agent which increases the flame retardancy of the web.
Claim 5
Dependent Claim
17 words
A fibrous web of claim 3 in which said agent comprises a brominated derivative of bisphenol A.
Claim 6
Dependent Claim
16 words
A fibrous web of claim 3 in which said flame retardant agent comprises 2,2 bis[3,5-dibromo-4-(2,3-dibromopropoxy phenyl)]propane.
Claim 7
Dependent Claim
25 words
A modified fibrous web electret comprising fibers fibrillated from a film comprising a nonpolar polymeric material and 2,2 bis[3,5-dibromo-4-(2,3-dibromopropoxy phenyl)]propane dispersed in the polymeric material.
Claim 8
Dependent Claim
25 words
A modified fibrous web electret comprising fibers fibrillated from a film comprising a nonpolar polymeric material and 2,2 bis[3,5-dibromo-4-(2,3-dibromopropoxy phenyl)]propane dispersed in the polymeric material.
Claim 9
Dependent Claim
14 words
A fibrous web of claim 6 in which the nonpolar polymeric material comprises polypropylene.
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) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |