Patent US4190707A successfully refreshed from Google Patents.
US4190707A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alkaline battery separator
Assignee: Asahi Kasei Corp
•
Filing: 1978-10-03
•
Granted: 1980-02-26
•
Expires: 1998-10-03
Abstract
Abstract An alkaline battery separator made of a porous film which consists substantially of a polyolefin having a weight average molecular weight of less than 300,000 and a number average molecular weight of 15,000 or more and which has a thickness of 0.025 to 1 mm, a porosity of 50 to 80%, an average pore diameter of 0.05 to 0.5μ and an average ratio of the larger dimension to the smaller dimension of the pore opening of not more than 2. The alkaline battery separator has not only an extremely low electrical resistance and a high alkali resistance but also a transmission-inhibitive ability for the active materials of battery and is excellent in mechanical strength and flexibility. It does not show appreciable shrinkage by heat. For producing such an alkaline battery separator, 10 to 50 volume percent of a polyolefin, 7 to 42 volume percent of an inorganic filler and 30 to 75 volume percent of an organic liquid having a solubility parameter of from 8.6 to 9.9 inclusive are blended, the amount of the polyolefin being 2/3 to 9 multiple of the amount of the inorganic filler, and the resulting blend is subjected to melt-molding to form a film, followed by extraction of the organic liquid and the inorganic filler from the film. In the extraction of the organic liquid and the inorganic filler, the film does not undergo shrinkage to provide a separator having excellent characteristics.
Inventors
- 👤 Yoshinao Doi
- 👤 Mitsuo Kohno
- 👤 Katsumi Yoshitake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:52
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/26; H; H01; H01M; H01M50/00; H01M50/40; H01M50/409; H01M50/411; H01M50/414; H01M50/417; H01M50/489; H01M50/491; H01M2300/00; H01M2300/0002; H01M2300/0014; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
91 words
An alkaline battery separator made of a porous film which consists substantially of a polyolefin having a weight average molecular weight of less than 300,000 and a number average molecular weight of 15,000 or more and which has a thickness of 0.025 to 1 mm, a porosity of 50 to 80%, an average pore diameter of 0.05 to 0.5μ, an average ratio of the larger dimension to the smaller dimension of the pore opening of not more than 2 and an electrical resistance of 0.00005 to 0.0005Ω dm 2 /0.1 mm.
Claim 2
Dependent Claim
91 words
An alkaline battery separator made of a porous film which consists substantially of a polyolefin having a weight average molecular weight of less than 300,000 and a number average molecular weight of 15,000 or more and which has a thickness of 0.025 to 1 mm, a porosity of 50 to 80%, an average pore diameter of 0.05 to 0.5μ, an average ratio of the larger dimension to the smaller dimension of the pore opening of not more than 2 and an electrical resistance of 0.00005 to 0.0005Ω dm 2 /0.1 mm.
Claim 3
Dependent Claim
21 words
An alkaline battery separator according to claim 1, wherein said polyolefin has a weight average molecular weight of 250,000 or less.
Claim 4
Dependent Claim
20 words
An alkaline battery separator according to claim 2, said polyolefin has a weight average molecular weight of 85,000 to 250,000.
Claim 5
Dependent Claim
21 words
An alkaline battery separator according to claim 1, wherein said polyolefin has a number average molecular weight of 17,000 or more.
Claim 6
Dependent Claim
21 words
An alkaline battery separator according to claim 4, wherein said polyolefin has a number average molecular weight of 17,000 to 50,000.
Claim 7
Dependent Claim
16 words
An alkaline battery separator according to claim 1, wherein said thickness is 0.03 to 0.3 mm.
Claim 8
Dependent Claim
15 words
An alkaline battery separator according to claim 1, wherein said porosity is 55 to 75%.
Claim 9
Dependent Claim
17 words
An alkaline battery separator according to claim 1, wherein said average pore diameter is 0.08 to 0.3μ.
Claim 10
Dependent Claim
29 words
An alkaline battery separator according to claim 1, wherein said average ratio of the larger dimension to the smaller dimension of the pore opening is not more than 1.5.
Claim 11
Dependent Claim
15 words
An alkaline battery separator according to claim 1, wherein said polyolefin is an olefin homopolymer.
Claim 12
Dependent Claim
15 words
An alkaline battery separator according to claim 1, wherein said polyolefin is an olefin copolymer.
Claim 13
Dependent Claim
13 words
An alkaline battery separator according to claim 10, wherein said polyolefin is polyethylene.
Claim 14
Dependent Claim
15 words
An alkaline battery separator according to claim 11, wherein said polyolefin is an ethylene copolymer.
Claim 15
Dependent Claim
32 words
An alkaline battery separator according to claim 13, wherein said ethylene copolymer is a copolymer of ethylene with at least one member selected from the group consisting of propylene, butene and hexene.
Claim 16
Dependent Claim
24 words
An alkaline battery separator according to claim 13, wherein aid ethylene copolymer is a copolymer of ethylene as a main component with other olefin.
Claim 17
Dependent Claim
44 words
An alkaline battery separator according to claim 1, wherein said porous film shows a heat shrinkage of not more than 6% after it has been immersed in an aqueous potassium hydroxide solution having a specific gravity of 1.3 at 105° C. for 30 minutes.
Claim 18
Independent Claim
124 words
A method of producing an alkaline battery separator made of a porous film which comprises blending a polyolefin having a weight average molecular weight of less than 300,000 and a number average molecular weight of 15,000 or more, an inorganic filler, and an organic liquid having a solubility parameter ranging from 8.6 to 9.9 inclusive in amounts of 10 to 50 volume percent, 7 to 42 volume percent, and 30 to 75 volume percent, respectively, based on the whole volume of the polyolefin-filler-organic liquid composition, the amount of the polyolefin being 2/3 to 9 multiple of the amount of the inorganic filler; subjecting the resulting blend to melt-molding to form a film; and extracting from said film the organic liquid and the inorganic filler.
Claim 19
Independent Claim
124 words
A method of producing an alkaline battery separator made of a porous film which comprises blending a polyolefin having a weight average molecular weight of less than 300,000 and a number average molecular weight of 15,000 or more, an inorganic filler, and an organic liquid having a solubility parameter ranging from 8.6 to 9.9 inclusive in amounts of 10 to 50 volume percent, 7 to 42 volume percent, and 30 to 75 volume percent, respectively, based on the whole volume of the polyolefin-filler-organic liquid composition, the amount of the polyolefin being 2/3 to 9 multiple of the amount of the inorganic filler; subjecting the resulting blend to melt-molding to form a film; and extracting from said film the organic liquid and the inorganic filler.
Claim 20
Dependent Claim
19 words
A method according to claim 17, wherein said polyolefin has a weight average molecular weight of 250,000 or less.
Claim 21
Dependent Claim
18 words
A method according to claim 18, said polyolefin has a weight average molecular weight of 85,000 to 250,000.
Claim 22
Dependent Claim
19 words
A method according to claim 17, wherein said polyolefin has a number average molecular weight of 17,000 or more.
Claim 23
Dependent Claim
19 words
A method according to claim 20, wherein said polyolefin has a number average molecular weight of 17,000 to 50,000.
Claim 24
Dependent Claim
13 words
A method according to claim 17, wherein said polyolefin is an olefin homopolymer.
Claim 25
Dependent Claim
13 words
A method according to claim 17, wherein said polyolefin is an olefin copolymer.
Claim 26
Dependent Claim
11 words
A method according to claim 22, wherein said polyolefin is polyethylene.
Claim 27
Dependent Claim
13 words
A method according to claim 23, wherein said polyolefin is an ethylene copolymer.
Claim 28
Dependent Claim
30 words
A method according to claim 25, wherein said ethylene copolymer is a copolymer of ethylene with at least one member selected from the group consisting of propylene, butene and hexene.
Claim 29
Dependent Claim
22 words
A method according to claim 25, wherein said ethylene copolymer is a copolymer of ethylene as a main component with other olefin.
Claim 30
Dependent Claim
18 words
A method according to claim 17, wherein said solubility parameter of the organic liquid is 8.7 to 9.4.
Claim 31
Dependent Claim
13 words
A method according to claim 17, wherein said organic liquid is dioctyl phthalate.
Claim 32
Dependent Claim
19 words
A method according to claim 17, wherein said inorganic filler has an average particle size of 0.005 to 0.5μ.
Claim 33
Dependent Claim
21 words
A method according to claim 17, wherein said inorganic filler has a surface area of 50 to 500 m 2 /g.
Claim 34
Dependent Claim
12 words
A method according to claim 17, wherein said inorganic filler is silica.
Claim 35
Independent Claim
81 words
A method of producing an alkaline battery separator made of a porous film which comprises extracting the inorganic filler from a microporous film comprising 40 to 88 volume percent of a polyolefin having a weight average molecular weight of less than 300,000 and a number average molecular weight of 15,000 or more and 60 to 12 volume percent of an inorganic filler and having a void space rate of 30 to 75 volume percent based on the volume of the film.
Claim 36
Independent Claim
81 words
A method of producing an alkaline battery separator made of a porous film which comprises extracting the inorganic filler from a microporous film comprising 40 to 88 volume percent of a polyolefin having a weight average molecular weight of less than 300,000 and a number average molecular weight of 15,000 or more and 60 to 12 volume percent of an inorganic filler and having a void space rate of 30 to 75 volume percent based on the volume of the film.
Claim 37
Dependent Claim
17 words
A method according to claim 33, wherein the volume percent of the polyolefin is 50 to 80.
Claim 38
Dependent Claim
18 words
A method according to claim 33, wherein the volume percent of the inorganic filler is 50 to 20.
Claim 39
Dependent Claim
19 words
A method according to claim 33, wherein the volume percent of the void space rate is 45 to 65.
References Cited (Backward Citations)
US2676929A
Cited
US2700694A
Cited
US3045058A
Cited
US3558764A
Cited
US3351495A
Cited
US3536796A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-25 | 1983-08-27 | 1984-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-25 | 1987-08-27 | 1988-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-25 | 1991-08-27 | 1992-02-26 | $7700.00 | Window Closed / Lapsed |