US4734196A
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Process for producing micro-porous membrane of ultra-high-molecular-weight alpha-olefin polymer, micro-porous membranes and process for producing film of ultra-high-molecular-weight alpha-olefin polymer
Assignee: Tonen Chemical Corp
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Filing: 1986-02-24
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Granted: 1988-03-29
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Expires: 2006-02-24
Abstract
Abstract A micro-porous membrane of ultra-high-molecular-weight alpha-olefin polymer having a weight-average molecular weight greater than 5x105, the micro-porous membrane having through holes 0.01 to 1 micrometer in average pore size, with a void ratio from 30 to 90% and being oriented such that the linear draw ratio in one axis is greater than two and the areal draw ratio is greater than ten. The micro-porous membrane is obtained by forming a gel-like object from a solution of an alpha-olefin polymer having a weight-average molecular weight greater than 5x105, removing at least 10 wt % of the solvent contained in the gel-like object so that the gel-like object contains 10 to 90 wt % of alpa-olefin polymer, orientating the gel-like object at a temperature lower than that which is 10 DEG C. above the melting point of the alpa-olefin polymer, and removing the residual solvent from the orientated product. A film is produced from the orientated product by pressing the orientated product at a temperature lower than that of the melting point of the alpha-olefin polymer.
Inventors
- 👤 Koichi Kono
- 👤 Shoichi Mori
- 👤 Kenji Miyasaka
- 👤 Jyoichi Tabuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:54
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0009; B01D71/00; B01D71/06; B01D71/26; B01D71/262; C08J5/00; C08J5/18; B01D2323/00; B01D2323/08; B01D2323/081; B01D2323/12; B01D2325/00; B01D2325/34; C08J2201/00; C08J2201/04; C08J2201/052; C08J2201/054; C08J2201/0542; C08J2201/0543; C08J2201/0545; C08J2201/0546; C08J2323/00; C08J2323/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
66 words
A micro-porous membrane of ultra-high-molecular-weight alpha-olefin polymer having a weight-average molecular weight of about 5×10 5 or greater, said micro-porous membrane having holes 0.01 to 1 micrometer in average pore size. with a void ratio of from about 30 to 90% and being orientated such that the linear draw ratio in one axis is greater than two and the areal draw ratio is greater than 10.
Claim 2
Dependent Claim
66 words
A micro-porous membrane of ultra-high-molecular-weight alpha-olefin polymer having a weight-average molecular weight of about 5×10 5 or greater, said micro-porous membrane having holes 0.01 to 1 micrometer in average pore size. with a void ratio of from about 30 to 90% and being orientated such that the linear draw ratio in one axis is greater than two and the areal draw ratio is greater than 10.
Claim 3
Dependent Claim
137 words
A process for producing a micro-porous membrane of ultra-high-molecular-weight alpha-olefin polymer which comprises the steps of: (A) forming a gel-like object from a solution of an alpha-olefin polymer having a weight-average molecular weight of about 5×10 5 or greater, (B) removing at least 10 wt. % of the solvent contained in the gel-like object so that the gel-like object contains 10 to 90 wt. % of the alpha-olefin polymer, (C) biaxially orientating the gel-like object obtained from step (B) at a temperature lower than that which is 10° C. above the melting point of the alpha-olefin polymer and at a linear draw ratio greater than 2 and an areal draw ratio greater than 10, and (D) removing the residual solvent from the orientated product thereby obtaining a micro-porous membrane having a void ratio of 30 to 90%.
Claim 4
Dependent Claim
137 words
A process for producing a micro-porous membrane of ultra-high-molecular-weight alpha-olefin polymer which comprises the steps of: (A) forming a gel-like object from a solution of an alpha-olefin polymer having a weight-average molecular weight of about 5×10 5 or greater, (B) removing at least 10 wt. % of the solvent contained in the gel-like object so that the gel-like object contains 10 to 90 wt. % of the alpha-olefin polymer, (C) biaxially orientating the gel-like object obtained from step (B) at a temperature lower than that which is 10° C. above the melting point of the alpha-olefin polymer and at a linear draw ratio greater than 2 and an areal draw ratio greater than 10, and (D) removing the residual solvent from the orientated product thereby obtaining a micro-porous membrane having a void ratio of 30 to 90%.
Claim 5
Dependent Claim
13 words
The process in accordance with claim 2 wherein the alpha-olefin polymer is polypropylene.
Claim 6
Dependent Claim
13 words
The proess in accordance with claim 2 wherein the alpha-olefin polymer is polypropylene.
Claim 7
Dependent Claim
14 words
The micro-porous membrane in accordane with claim 2 wherein the alpha-olefin polymer is polypropylene.
Claim 8
Dependent Claim
146 words
A process for producing film of ultra-high-molecular-weight alpha-olefin polymer which comprises the steps of: (A) forming a gel-like object from a solution of an alpha-olefin polymer having a weight-average molecular weight of about 5×105 or greater, (B) removing at least 10 wt. % of the solvent contained in the gel-like object so that the gel-like object contains 10 to 90 wt. % of the alpha-olefin polymer, (C) biaxially orientating the gel-like object at a temperature lower than that which is 10° C. above the melting point of the alpha-olefin polymer at a linar draw ratio greater than 2 and an areal draw ratio greater than 10, (D) removing the residual solvent from the orientated product thereby obtaining a micro-porous membrane having a void ratio of 30 to 90%, and (E) pressing the orientated product at a temperature lower than the melting point of the alpha-olefin polymer.
Claim 9
Dependent Claim
146 words
A process for producing film of ultra-high-molecular-weight alpha-olefin polymer which comprises the steps of: (A) forming a gel-like object from a solution of an alpha-olefin polymer having a weight-average molecular weight of about 5×105 or greater, (B) removing at least 10 wt. % of the solvent contained in the gel-like object so that the gel-like object contains 10 to 90 wt. % of the alpha-olefin polymer, (C) biaxially orientating the gel-like object at a temperature lower than that which is 10° C. above the melting point of the alpha-olefin polymer at a linar draw ratio greater than 2 and an areal draw ratio greater than 10, (D) removing the residual solvent from the orientated product thereby obtaining a micro-porous membrane having a void ratio of 30 to 90%, and (E) pressing the orientated product at a temperature lower than the melting point of the alpha-olefin polymer.
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) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |