US Patent No: 5,480,745
Number of patents in Portfolio can not be more than 2000
Porous film and use of the same
Stats
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Jan 2, 1996
Issued date -
Jan 31, 1995
filing date -
08/381,395
serial no -
In Force
status
Importance
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Abstract
A porous film, a process for producing the same, a battery separator comprising the porous film, and a battery having incorporated therein the separator are disclosed. The porous film comprises a polyethylene and a polypropylene as the essential components, wherein the polyethylene content in the total weight of polyethylene and polypropylene is from 2 to 40% by weight and the polyethylene content is changed in the direction of the thickness of the film, and is produced by forming a laminate film comprising at least one polypropylene layer and at least one layer of a mixture of polyethylene and polypropylene as the essential components, the polyethylene content in the film being from 2 to 40% by weight, uniaxially stretching the laminate film at a low-temperature range of from -20.degree. C. to 80.degree. C. and then stretching the film at a high-temperature range of from 90.degree. C. to 150.degree. C.
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First Claim
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International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
|---|---|---|---|
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| 4,650,730 Battery separator | 64 | 1985 | |
| 4,731,304 Battery separator | 51 | 1986 | |
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| 4,789,609 Battery separator | 6 | 1987 | |
| 5,362,582 Battery separator | 12 | 1993 | |
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| 4,181,651 Method for hydrolysis of casein using orthophosphorous acids or salts thereof and montmorillonite | 3 | 1978 | |
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| 4,206,257 Napped sheet material bearing the characteristics of a suede-leather and method of producing the same | 7 | 1978 | |
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| 4,201,838 Laminated microporous article | 25 | 1978 | |
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| 4,863,792 Multi-layer laminates of microporous films | 48 | 1988 | |
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| 5,385,777 Porous film, process for producing the same, and use of the same | 11 | 1993 | |
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| 4,877,679 Multilayer article of microporous and porous materials | 81 | 1988 | |
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| 5,320,916 Separator for alkali-zinc battery | 2 | 1992 | |