Patent US3905229A successfully refreshed from Google Patents.
US4386129A
Expired / Lapsed
US
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Porous polymeric films
Assignee: BP Corp North America Inc
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Filing: 1981-03-31
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Granted: 1983-05-31
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Expires: 2001-03-31
Abstract
Abstract This invention relates to porous films having pores with polygonal cross sections and average pore diameters of about 3 to about 100 microns and the method for preparing these films. More particularly this invention relates to a porous film having pores with polygonal cross sections and average pore diameters of about 3 to about 100 microns formed from a resinous polymer of propylene and the process for forming the film which comprises the steps of (a) forming a film containing beta-spherulites and (b) selectively extracting the beta-spherulites.
Inventors
- 👤 Philip Jacoby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:52
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/26; B; B29; B29C; B29C67/00; B29C67/20; B29C67/202; C08J5/00; C08J5/18; C08J2201/00; C08J2201/04; C08J2201/042; C08J2201/0424; C08J2323/00; C08J2323/02; C08J2323/10; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/31504; Y10T428/31855; Y10T428/31938
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
44 words
A porous film with a thickness of about 0.010 to about 0.25 millimeters comprising a resinous polymer of propylene having alpha-form spherulites and polygonal pores with average diameters of about 3 to about 100 microns said pores corresponding to the location of beta-form spherulites.
Claim 2
Dependent Claim
44 words
A porous film with a thickness of about 0.010 to about 0.25 millimeters comprising a resinous polymer of propylene having alpha-form spherulites and polygonal pores with average diameters of about 3 to about 100 microns said pores corresponding to the location of beta-form spherulites.
Claim 3
Dependent Claim
113 words
A porous film having polygonal pores with average pore diameters from about 3 to about 100 microns said film prepared from resinous polymers of propylene capable of having at least 40% crystallinity by a process comprising the steps of (a) dispersing in said resinous polymer a nucleating agent capable of producing beta-spherulites; (b) forming by extrusion a film with a thickness of about 0.010 to about 0.25 millimeters from the molten product of step (a); (c) cooling said film below the crystallization temperature of said polymer to form beta-spherulites; and (d) selectively extracting said beta-spherulites from the cooled film product of step (c) with an extracting solvent to form the porous film product.
Claim 4
Dependent Claim
113 words
A porous film having polygonal pores with average pore diameters from about 3 to about 100 microns said film prepared from resinous polymers of propylene capable of having at least 40% crystallinity by a process comprising the steps of (a) dispersing in said resinous polymer a nucleating agent capable of producing beta-spherulites; (b) forming by extrusion a film with a thickness of about 0.010 to about 0.25 millimeters from the molten product of step (a); (c) cooling said film below the crystallization temperature of said polymer to form beta-spherulites; and (d) selectively extracting said beta-spherulites from the cooled film product of step (c) with an extracting solvent to form the porous film product.
Claim 5
Dependent Claim
113 words
A process for preparing a porous film having polygonal pores with average pore diameters from about 3 to about 100 microns from resinous polymers of propylene capable of having at least 40% crystallinity said process comprising the steps of (a) dispersing in said resinous polymer a nucleating agent capable of producing beta-spherulites; (b) forming by extrusion a film with a thickness of about 0.010 to about 0.25 millimeters from the molten product of step (a); (c) cooling said film below the crystallization temperature of said polymer to form beta-spherulites; and (d) selectively extracting said beta-spherulites from the cooled film product of step (c) with an extracting solvent to form the porous film product.
Claim 6
Dependent Claim
113 words
A process for preparing a porous film having polygonal pores with average pore diameters from about 3 to about 100 microns from resinous polymers of propylene capable of having at least 40% crystallinity said process comprising the steps of (a) dispersing in said resinous polymer a nucleating agent capable of producing beta-spherulites; (b) forming by extrusion a film with a thickness of about 0.010 to about 0.25 millimeters from the molten product of step (a); (c) cooling said film below the crystallization temperature of said polymer to form beta-spherulites; and (d) selectively extracting said beta-spherulites from the cooled film product of step (c) with an extracting solvent to form the porous film product.
Claim 7
Dependent Claim
14 words
The process of claim 3 wherein said nucleating agent has the structural formula ##STR2##
Claim 8
Dependent Claim
21 words
The process of claim 1 wherein said extracting solvent is selected from the group consisting of toluene, carbon tetrachloride, or xylene.
Claim 9
Dependent Claim
25 words
The process of claim 3 wherein at least 50 percent of the pores of said porous film have an average diameter greater than 5 microns.
Claim 10
Dependent Claim
127 words
A process for preparing a porous film from resinous polymers of propylene capable of having at least 40% crystallinity said process comprising the steps of (a) dispersing in said resinous polymer a nucleating agent capable of producing beta-spherulites; (b) forming by extrusion a film with a thickness of about 0.010 to about 0.25 millimeters from the molten product of step (a); (c) cooling said film below the crystallization temperature of said polymer to form beta-spherulites; and (d) contacting the film of step (c) with an extracting solvent at a temperature of about 95° C. to about 100° C. to selectively extract at least a portion of said beta-spherulites to form the porous film having polygonal pores with average pore diameters from about 3 to about 100 microns.
Claim 11
Dependent Claim
127 words
A process for preparing a porous film from resinous polymers of propylene capable of having at least 40% crystallinity said process comprising the steps of (a) dispersing in said resinous polymer a nucleating agent capable of producing beta-spherulites; (b) forming by extrusion a film with a thickness of about 0.010 to about 0.25 millimeters from the molten product of step (a); (c) cooling said film below the crystallization temperature of said polymer to form beta-spherulites; and (d) contacting the film of step (c) with an extracting solvent at a temperature of about 95° C. to about 100° C. to selectively extract at least a portion of said beta-spherulites to form the porous film having polygonal pores with average pore diameters from about 3 to about 100 microns.
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) | 1986-05-30 | 1986-11-29 | 1987-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-30 | 1990-11-29 | 1991-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-30 | 1994-11-29 | 1995-05-31 | $7700.00 | Window Closed / Lapsed |