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US4873034A
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Process for producing microporous ultra-high-molecular-weight polyolefin membrane
Assignee: Tonen General Sekiyu KK
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Filing: 1988-07-22
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Granted: 1989-10-10
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Expires: 2008-07-22
Abstract
Abstract A process for producing a relatively thick microporous ultra-high-molecular-weight polyolefin membrane, including the steps of: (1) preparing a solution of an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×10 5 or more; (b) extruding the solution from a die while rapidly cooling it in advance to its gelation temperature or below, thereby forming a gel-like sheet; (c) removing at least 10 wt % of the solvent from the gel-like sheet so that the gel-like sheet contains 10 to 90 wt % of the ultra-high-molecular-weight polyolefin; (d) stretching the gel-like sheet at a temperature equal to or lower than that which is 10° C. above the melting point of the ultra-high-molecular-weight polyolefin; and (e) removing the residual solvent from the stretched product.
Inventors
- 👤 Koichi Kono
- 👤 Kenkichi Okamoto
- 👤 Rumi Iwasaki
- 👤 Shuichi Sawada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:43
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/022; B29C55/00; B29C55/005; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/0025; B01D67/0027; B01D71/00; B01D71/06; B01D71/26; B01D71/261; B29C48/03; B29C48/07; B29C48/08; B29C48/25; B29C48/88; B29C48/919; C; C08; C08J; C08J5/00; C08J5/18; C08J9/00; C08J9/28; H; H01; H01M; H01M50/00; H01M50/40; H01M50/489; B01D2323/00; B01D2323/08; B01D2323/081; B01D2323/082; B01D2325/00; B01D2325/24; B29C48/05; B29K; B29K2023/00; B29K2105/00; B29K2105/04; B29K2995/00; B29K2995/0037; B29K2995/0088; C08J2201/00; C08J2201/02; C08J2201/03; C08J2201/04; C08J2201/054; C08J2201/0542; C08J2201/0543; C08J2201/0545; C08J2201/0546; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
121 words
A process for producing a microporous ultra-high-molecular-weight polyolefin membrane, comprising the steps of: (a) preparing a solution of an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×10 5 or more; (b) extruding said solution from a die, said solution being rapidly cooled to its gelation temperature or below before extrusion, thereby forming a gel-like sheet; (c) removing at least 10 wt % of said solvent from said gel-like sheet so that said gel-like sheet contains 10 to 90 wt % of said ultra-high-molecular-weight polyolefin; (d) stretching said gel-like sheet at a temperature equal to or lower than that which is 10° C. above the melting point of said ultra-high-molecular-weight polyolefin; and (e) removing the residual solvent from the stretched product.
Claim 2
Dependent Claim
121 words
A process for producing a microporous ultra-high-molecular-weight polyolefin membrane, comprising the steps of: (a) preparing a solution of an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×10 5 or more; (b) extruding said solution from a die, said solution being rapidly cooled to its gelation temperature or below before extrusion, thereby forming a gel-like sheet; (c) removing at least 10 wt % of said solvent from said gel-like sheet so that said gel-like sheet contains 10 to 90 wt % of said ultra-high-molecular-weight polyolefin; (d) stretching said gel-like sheet at a temperature equal to or lower than that which is 10° C. above the melting point of said ultra-high-molecular-weight polyolefin; and (e) removing the residual solvent from the stretched product.
Claim 3
Dependent Claim
23 words
The process according to claim 1, wherein said ultra-high-molecular-weight polyolefin solution is rapidly cooled at a cooling rate of 50° C./minute or more.
Claim 4
Dependent Claim
21 words
The process according to claim 1, wherein said ultra-high-molecular-weight polyolefin solution is rapidly cooled by the die which is being cooled.
Claim 5
Dependent Claim
19 words
The process according to claim 1, wherein the cooling temperature in said step (b) is 90° C. or less.
Claim 6
Dependent Claim
29 words
The process according to claim 1, wherein the gel-like sheet is stretched at a temperature between the crystal dispersion temperature and the crystal melting point of said ultra-high-molecular-weight polyolefin.
Claim 7
Dependent Claim
20 words
The process according to claim 1, wherein said ultra-high-molecular-weight polyolefin is dissolved in a nonvolatile solvent in said step (a).
Claim 8
Dependent Claim
13 words
The process according to claim 6, wherein said nonvolatile solvent is paraffin oil.
Claim 9
Dependent Claim
18 words
The process according to claim 1, wherein said residual solvent is removed by extraction with a volatile solvent.
Claim 10
Dependent Claim
17 words
The process according to any of claims 1 to 8, wherein said ultra-high-molecular-weight polyolefin is ultra-high-molecular-weight polyethylene.
References Cited (Backward Citations)
US3954927A
Cited
JPS585228A
Cited
US4413110A
Cited
US4472328A
Cited
US4551296A
Cited
JPS60242035A
Cited
US4588633A
Cited
US4620955A
Cited
US4734196A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |