US4354986A
Expired / Lapsed
US
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Process for manufacturing boron nitride fiber mats using a needler
Assignee: Stemcor Corp
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Filing: 1980-06-04
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Granted: 1982-10-19
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Expires: 2000-06-04
Abstract
Abstract A process is disclosed for producing a non-woven, boron nitride fiber mat, suitable for use as an electric cell separator in a lithium-sulfide battery. Molten boron oxide is centrifugally spun into strands and attenuated by an annular gas stream into fibers which are compacted at a controlled relative humidity into a mat. The mat of fibers passes through a needler, which repeatedly drives arrays of needles into the mat from either one or both sides, to reorient and intertwine the fibers, producing additional mechanical bonds thereamong. The needled mat then is heated in an anhydrous ammonia atmosphere to convert boron oxide in the fibers into boron nitride (BN). In an alternate embodiment the boron oxide fibers within the mat are converted into boron nitride before being passed through the needler.
Inventors
- 👤 Jacob W. Maczuga
- 👤 Daniel C. Wilhelm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:24
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/06; C01B21/064; C03; C03B; C03B37/00; C03B37/01; C03B37/04; C04; C04B; C04B35/00; C04B35/622; C04B35/62227; C04B35/62272; C04B35/62286; C04B35/6229; D; D04; D04H; D04H1/00; D04H1/40; D04H1/44; D04H1/46; D04H1/54; D04H1/56; D04H18/00; D04H18/02; H; H01; H01M; H01M50/00; H01M50/40; H01M50/403; H01M50/409; H01M50/431; H01M50/434; H01M50/44; H01M50/489; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/34; C04B2235/3409; C04B2235/46; C04B2235/465; C04B2235/65; C04B2235/656; C04B2235/6562; H01M2300/00; H01M2300/0017; H01M2300/0048; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
78 words
A process for producing a non-woven, mechanically intertwined boron nitride fiber mat, comprising the steps of: centrifugally spinning molten boron oxide into strands; attenuating said strands with a gas stream into fibers; compacting said fibers into a mat; passing said mat through a needler to reorient and intertwine the fibers; and heating said mat in an anhydrous ammonia atmosphere at a sufficient temperature and for a sufficient time to convert boron oxide in the fibers into boron nitride.
Claim 2
Dependent Claim
78 words
A process for producing a non-woven, mechanically intertwined boron nitride fiber mat, comprising the steps of: centrifugally spinning molten boron oxide into strands; attenuating said strands with a gas stream into fibers; compacting said fibers into a mat; passing said mat through a needler to reorient and intertwine the fibers; and heating said mat in an anhydrous ammonia atmosphere at a sufficient temperature and for a sufficient time to convert boron oxide in the fibers into boron nitride.
Claim 3
Dependent Claim
25 words
The process as set forth in claim 1 wherein said sufficient temperature to convert the fibers into boron nitride is from 700° to 1100° C.
Claim 4
Dependent Claim
29 words
The process as set forth in claim 1 wherein the step of passing said mat through a needler increases the density of said mat by about 300 to 400%.
Claim 5
Dependent Claim
74 words
The process as set forth in claim 1 wherein said needler comprises: a first plate; a second plate spaced apart from, and oriented generally parallel to, said first plate; means for varying the spacing between said plates; and a first array of needles attached perpendicularly to the inwardly facing surface of said first plate, each needle having a maximum diameter of 16 gauge and being separated from adjacent needles by 0.01 to 1 inch.
Claim 6
Dependent Claim
84 words
The process as set forth in claim 4 wherein said needler further comprises: a second array of needles attached perpendicularly to the inwardly facing surface of said second plate, each needle having a maximum diameter of 16 gauge and being separated from adjacent needles by 0.01 to 1 inch, the needles of said second array being displaced laterally from the needles of said first array whereby the needles of said second array are positioned opposite the spaces between the needles of said first array.
Claim 7
Dependent Claim
20 words
The process as set forth in claim 4 wherein said mat passes through said needler 0.22 inch at a time.
Claim 8
Dependent Claim
82 words
A process for producing a non-woven, mechanically intertwined boron nitride fiber mat, comprising the steps of: centrifugally spinning molten boron oxide into strands; attenuating said strands with a gas stream into fibers; compacting said fibers into a mat; heating said mat in an anhydrous ammonia atmosphere at a sufficient temperature and for a sufficient time to convert boron oxide in the fibers into boron nitride; and passing said mat of boron nitride fibers through a needler to reorient and intertwine said fibers.
Claim 9
Dependent Claim
82 words
A process for producing a non-woven, mechanically intertwined boron nitride fiber mat, comprising the steps of: centrifugally spinning molten boron oxide into strands; attenuating said strands with a gas stream into fibers; compacting said fibers into a mat; heating said mat in an anhydrous ammonia atmosphere at a sufficient temperature and for a sufficient time to convert boron oxide in the fibers into boron nitride; and passing said mat of boron nitride fibers through a needler to reorient and intertwine said fibers.
Claim 10
Dependent Claim
25 words
The process as set forth in claim 7 wherein said sufficient temperature to convert the fibers into boron nitride is from 700° to 1100° C.
Claim 11
Dependent Claim
29 words
The process as set forth in claim 7 wherein the step of passing said mat through a needler increases the density of said mat by about 300 to 400%.
Claim 12
Dependent Claim
74 words
The process as set forth in claim 7 wherein said needler comprises: a first plate; a second plate spaced apart from, and oriented generally parallel to, said first plate; means for varying the spacing between said plates; and a first array of needles attached perpendicularly to the inwardly facing surface of said first plate, each needle having a maximum diameter of 16 gauge and being separated from adjacent needles by 0.01 to 1 inch.
Claim 13
Dependent Claim
84 words
The process as set forth in claim 10 wherein said needler further comprises: a second array of needles attached perpendicularly to the inwardly facing surface of said second plate, each needle having a maximum diameter of 16 gauge and being separated from adjacent needles by 0.01 to 1 inch, the needles of said second array being displaced laterally from the needles of said first array whereby the needles of said second array are positioned opposite the spaces between the needles of said first array.
Claim 14
Dependent Claim
20 words
The process as set forth in claim 10 wherein said mat passes through said needler 0.22 inch at a time.
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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) | 1985-10-18 | 1986-04-19 | 1986-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-18 | 1990-04-19 | 1990-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-18 | 1994-04-19 | 1994-10-19 | $7700.00 | Window Closed / Lapsed |