US4814124A
Expired / Lapsed
US
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Preparation of gas permeable porous film
Assignee: Mitsui Chemicals Inc
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Filing: 1987-01-20
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Granted: 1989-03-21
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Expires: 2007-01-20
Abstract
Abstract A gas permeable porous film which is prepared by stretching a film made from a mixture containing a polyolefin resin and an inorganic filler at least uniaxially and possesses a rugged pattern on its surface. One process for producing the film comprises forming the aforesaid mixture into a film, providing on the surface of the film a rugged pattern, stretching the resulting film at least uniaxially, and forming on the stretched film thus-formed a rugged pattern by means of a heated emboss roll and simultaneously allowing the stretched film to contract.
Inventors
- 👤 Mari Aoyama
- 👤 Michiyasu Ito
- 👤 Syoichi Tsuji
- 👤 Toshiyuki Ishii
- 👤 Tomohide Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:14
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B29; B29C; B29C55/00; B29C55/02; B29C55/18; B29C59/00; B29C59/02; B29C59/04; C08K; C08K3/00; C08K3/01; C08K3/013; B29C59/022; B29C2059/023; B29C2791/00; B29C2791/001; B29K; B29K2023/00; B29K2105/00; B29K2105/04; B29K2105/06; B29K2105/16; B29K2995/00; B29K2995/0037; B29K2995/0065; B29K2995/0072; C08J2323/00; C08J2323/02; Y; Y10; Y10S; Y10S264/00; Y10S264/47
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
98 words
In a process for preparing a gas-permeable, porous film, which comprises the steps of (a) mixing a polyolefin resin and an inorganic filler, (b) forming a film from the mixture and (c) stretching the resulting film to form the porous film, the improvement consisting of a first embossing of said film prior to stretching it, so as to produce only a rough surface thereon; and a second embossing of the stretched film, so as to produce a distinct rugged pattern on said film having peaks and valleys with a surface depth of from 2 microns to 3 millimeters.
Claim 2
Dependent Claim
98 words
In a process for preparing a gas-permeable, porous film, which comprises the steps of (a) mixing a polyolefin resin and an inorganic filler, (b) forming a film from the mixture and (c) stretching the resulting film to form the porous film, the improvement consisting of a first embossing of said film prior to stretching it, so as to produce only a rough surface thereon; and a second embossing of the stretched film, so as to produce a distinct rugged pattern on said film having peaks and valleys with a surface depth of from 2 microns to 3 millimeters.
Claim 3
Dependent Claim
122 words
In a process for preparing a ga-permeable, porous film, which comprises the steps of (a) mixing a polyolefin resin and an inorganic filler, (b) forming a film from the mixture and (c) stretching the resulting film to form the porous film, the improvement consisting of a first embossing of said film prior to stretching it, so as to produce only a rough surface thereon; and a second embossing of the stretched film with rollers heated at a temperature of between 40 degrees C. below and 20 degrees C. above the melting temperature of the polyolefin resin, so as to produce a distinct rugged pattern on said film having peaks and valleys with a surface depth of from 2 microns to 3 millimeters.
Claim 4
Dependent Claim
122 words
In a process for preparing a ga-permeable, porous film, which comprises the steps of (a) mixing a polyolefin resin and an inorganic filler, (b) forming a film from the mixture and (c) stretching the resulting film to form the porous film, the improvement consisting of a first embossing of said film prior to stretching it, so as to produce only a rough surface thereon; and a second embossing of the stretched film with rollers heated at a temperature of between 40 degrees C. below and 20 degrees C. above the melting temperature of the polyolefin resin, so as to produce a distinct rugged pattern on said film having peaks and valleys with a surface depth of from 2 microns to 3 millimeters.
Claim 5
Dependent Claim
36 words
The process according to claim 2, wherein said second embossing is effected while simultaneously allowing the film to shrink area-wise by 5-50 percent, said stretching being effected at a stretching ratio, on area basis, of 4-25.
Claim 6
Dependent Claim
27 words
The process according to claim 2, wherein said film is restretched prior to said second embossing at a stretching ratio, on area basis, of at least 1.03.
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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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |