Patent US4863792A successfully refreshed from Google Patents.
US4863792A
Expired / Lapsed
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Multi-layer laminates of microporous films
Assignee: 3M Co
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Filing: 1988-10-14
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Granted: 1989-09-05
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Expires: 2008-10-14
Abstract
Abstract Multi-layer, microporous polyolefin sheet materials are provided. The sheet materials comprise at least two microporous polyolefin layers, the layers being autogenously bonded and having substantially the same porosity as prior to bonding.
Inventors
- 👤 James S. Mrozinski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:19
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/0025; B01D67/0027; B01D67/003; B01D69/00; B01D69/12; B01D69/1214; B01D71/00; B01D71/06; B01D71/26; B01D71/261; B01D71/262; B32B27/06; B32B27/08; B32B27/18; B32B27/24; B32B5/00; B32B5/22; B32B5/32; C; C08; C08J; C08J5/00; C08J5/12; C08J5/122; C08J9/00; C08J9/28; H; H01; H01M; H01M50/00; H01M50/40; H01M50/409; H01M50/411; H01M50/414; H01M50/417; H01M50/449; H01M50/454; H01M50/489; H01M50/491; B01D2323/00; B01D2323/15; B01D2323/16; B32B38/00; B32B38/16; B32B38/164; B32B2038/168; B32B2305/00; B32B2305/02; B32B2305/026; B32B2307/00; B32B2307/50; B32B2307/514; B32B2323/00; B32B2323/04; B32B2323/10; C08J2201/00; C08J2201/04; C08J2201/052; C08J2201/054; C08J2201/0542; C08J2201/0543; C08J2201/0545; C08J2201/0546; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249979; Y10T428/249981
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
27 words
Multi-layer, microporous polyolefin sheet materials comprising at least two microporous polyolefin layers, the layers being autogenously bonded and having substantially the same porosity as prior to bonding.
Claim 2
Dependent Claim
27 words
Multi-layer, microporous polyolefin sheet materials comprising at least two microporous polyolefin layers, the layers being autogenously bonded and having substantially the same porosity as prior to bonding.
Claim 3
Dependent Claim
13 words
The sheet material of claim 1 wherein said layers have the same porosities.
Claim 4
Dependent Claim
12 words
The sheet material of claim 1 wherein said layers have different porosities.
Claim 5
Dependent Claim
15 words
The sheet material of claim 1 wherein said layers are of the same polyolefin material.
Claim 6
Dependent Claim
14 words
The sheet material of claim 1 wherein said layers are of different polyolefin material.
Claim 7
Dependent Claim
16 words
The sheet material of claim 1 wherein said polyolefin is polyethylene, polypropylene or a combination thereof.
Claim 8
Independent Claim
127 words
A method of making multi-layer, microporous polyolefin sheet materials comprising the steps of (a) forming at least two microporous polyolefin layers by melt blending the polyolefin with an additive which is miscible with the polymer at the melt temperature of the blend but which phase separates on cooling, forming a layer from the solution, cooling the layer at a rate and to a temperature to initiate non-equilibrium phase separation, and cooling to solidify the layer; (b) extracting the additive from each layer with a solvent capable of swelling the polyolefin and contacting the solvent wet layers or contacting the solvent wet layers and extracting the additives from the contacting layers; and (c) drying the contacting layers to remove the solvent and effect bonding between the contacting layers.
Claim 9
Independent Claim
127 words
A method of making multi-layer, microporous polyolefin sheet materials comprising the steps of (a) forming at least two microporous polyolefin layers by melt blending the polyolefin with an additive which is miscible with the polymer at the melt temperature of the blend but which phase separates on cooling, forming a layer from the solution, cooling the layer at a rate and to a temperature to initiate non-equilibrium phase separation, and cooling to solidify the layer; (b) extracting the additive from each layer with a solvent capable of swelling the polyolefin and contacting the solvent wet layers or contacting the solvent wet layers and extracting the additives from the contacting layers; and (c) drying the contacting layers to remove the solvent and effect bonding between the contacting layers.
Claim 10
Dependent Claim
11 words
The method of claim 7 further comprising orienting said sheet materials.
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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) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |