US4734344A
Expired / Lapsed
US
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Battery separator
Assignee: Daramic LLC
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Filing: 1986-05-19
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Granted: 1988-03-29
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Expires: 2006-05-19
Abstract
Abstract The present invention is a sheet material for use in alkaline batteries as a separator or interseparator. The sheet is formed of about 30 to about 70 percent polyolefin synthetic pulp, from about 15 to about 65 percent alkali resistant inorganic filler and from about 1 to about 35 percent of one or more long fibers, wherein at least some, if not all of the fiber is a water swellable polyvinyl alcohol based fiber and any remaining long fiber is a nonwater swellable fiber. The water swellable fiber during processing of the sheet forms a gel-like network when contacted by water which retains the filler and bonds the remaining materials together. The resulting sheet has increased tensile strength and alkali resistance and is especially useful in automated battery manufacturing processes.
Inventors
- 👤 Wai M. Choi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:35
CPC Classifications
H; H01; H01M; H01M50/00; H01M50/40; H01M50/489; H01M50/494; H01M50/409; H01M50/411; H01M50/414; H01M2300/00; H01M2300/0002; H01M2300/0014; H01M50/491; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10T; Y10T442/00; Y10T442/20; Y10T442/2549; Y10T442/2574
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
95 words
A sheet material for use in an alkaline battery system comprising from about 30 to about 70 weight percent of the sheet material of polyolefin synthetic pulp, from about 15 to about 65 weight percent of the sheet material of an alkali resistant inorganic filler, and from about 1 to 35 weight percent of the sheet material of long synthetic fibers having lengths of at least about 0.25 inch wherein at least some of the long synthetic fibers are water swellable vinyl alcohol so as to bind at least some of the remaining ingredients together.
Claim 2
Dependent Claim
95 words
A sheet material for use in an alkaline battery system comprising from about 30 to about 70 weight percent of the sheet material of polyolefin synthetic pulp, from about 15 to about 65 weight percent of the sheet material of an alkali resistant inorganic filler, and from about 1 to 35 weight percent of the sheet material of long synthetic fibers having lengths of at least about 0.25 inch wherein at least some of the long synthetic fibers are water swellable vinyl alcohol so as to bind at least some of the remaining ingredients together.
Claim 3
Dependent Claim
74 words
A sheet material of claim 1 wherein the polyolefin synthetic pulp is selected from polyethylene, polypropylene, or a combination thereof; the filler is selected from titanium dioxide, alumina, magnesia, potassium titanite, zirconium hydroxide, magnesium hydroxide or mixtures thereof; the water swellable vinyl alcohol long sythetic fibers are comprised of a polymer of vinyl alcohol and any remaining long synthetic fibers are selected from nonwater swellable polyvinyl alcohol, polyester, polyacrylic, polyamide, polyolefin and mixtures thereof.
Claim 4
Dependent Claim
27 words
The sheet material of claim 1 wherein the long synthetic fibers are a first water swellable polyvinyl alcohol fiber and a second nonwater swellable polyvinyl alcohol fiber.
Claim 5
Dependent Claim
25 words
The sheet material of claim 3 wherein the amount of water swellable fiber is equal to or less than the amount of nonwater swellable fiber.
Claim 6
Dependent Claim
24 words
The sheet material of claim 1 wherein the amount of long synthetic fiber is equal to or less than the amount of synthetic pulp.
Claim 7
Dependent Claim
22 words
The sheet material of claim 1 wherein the tensile strength of the sheet material is at least 400 pounds per square inch.
Claim 8
Dependent Claim
14 words
The sheet material of claim 2 wherein said vinyl alcohol polymer is a copolymer.
Claim 9
Dependent Claim
20 words
The sheet material of claim 7, wherein said vinyl alcohol polymer is a copolymer of vinyl alcohol and vinyl chloride.
Claim 10
Dependent Claim
25 words
The sheet material of claim 8 wherein said copolymer comprises a graft copolymer having a vinyl chloride backbone grafted with a water swellable vinyl alcohol.
Claim 11
Dependent Claim
31 words
The sheet material of claim 1 wherein the long synthetic fibers have a denier of about 1 to about 12 and a length of from about 0.25 to about 1.5 inches.
Claim 12
Dependent Claim
57 words
An alkali resistant sheet material comprising from about 30 to about 70 weight percent polyolefin synthetic pulp, from about 15 to 65 weight percent of filler and from about 1 to 35 weight percent of one or more long synthetic fibers, wherein at least some or all of the long synthetic fibers are water swellable vinyl alcohol.
Claim 13
Dependent Claim
57 words
An alkali resistant sheet material comprising from about 30 to about 70 weight percent polyolefin synthetic pulp, from about 15 to 65 weight percent of filler and from about 1 to 35 weight percent of one or more long synthetic fibers, wherein at least some or all of the long synthetic fibers are water swellable vinyl alcohol.
Claim 14
Dependent Claim
37 words
The alkali resistant sheet material of claim 11 wherein the water swellable long synthetic fibers are selected from polyvinyl alcohol fibers, a copolymer fiber comprising a polyvinyl chloride and a water swellable polyvinyl alcohol, and mixtures thereof.
Claim 15
Dependent Claim
28 words
The alkali resistant sheet material of claim 11 wherein the long synthetic fibers are comprised of water swellable fibers and a nonwater swellable fibers in approximately equal proportions.
Claim 16
Dependent Claim
47 words
The alkali resistant sheet material of claim 11 wherein the long synthetic fibers are a water swellable vinyl alcohol fiber and a nonwater swellable fiber and wherein the water swellable fiber is present in an amount equal to or less than that of the nonwater swellable fiber.
Claim 17
Dependent Claim
30 words
The alkali resistant sheet material of claim 11 wherein the long synthetic fibers have deniers of about 1.0 to about 12 and lengths of about 0.25 to about 1.5 inches.
Claim 18
Dependent Claim
79 words
A battery separator for use in alkaline batteries comprising a sheet of from about 30 to about 70 weight percent of the sheet of polyolefin synthetic pulp, from about 15 to 65 weight percent of the sheet of an alkali resistant inorganic filler, from about 0.5 to 17.5 weight percent of the sheet of a water swellable vinyl alcohol long fiber and from about 0.5 to about 17.5 weight percent of the sheet of a nonwater swellable long fiber.
Claim 19
Dependent Claim
79 words
A battery separator for use in alkaline batteries comprising a sheet of from about 30 to about 70 weight percent of the sheet of polyolefin synthetic pulp, from about 15 to 65 weight percent of the sheet of an alkali resistant inorganic filler, from about 0.5 to 17.5 weight percent of the sheet of a water swellable vinyl alcohol long fiber and from about 0.5 to about 17.5 weight percent of the sheet of a nonwater swellable long fiber.
Claim 20
Dependent Claim
95 words
The battery separator of claim 16 wherein the polyolefin pulp is selected from the group consisting of polyethylene, polypropylene or a combination thereof; the filler is selected from the group consisting of titanium dioxide, alumina, magnesia, potassium titanite, zirconium hydroxide, magnezium hydroxide or a mixture thereof; the water swellable vinyl alcohol long fiber is selected from the group consisting of polyvinyl alcohol, a copolymer of polyvinyl chloride and polyvinyl alcohol or mixtures thereof; and the nonwater swellable long fiber is selected from the group consisting of polyvinyl alcohol, polyester, polyacrylic, polymaide, polyolefin or mixtures thereof.
Claim 21
Dependent Claim
19 words
The battery separator of claim 16, wherein the sheet material has a tensile strength of at least 400 psi.
Claim 22
Dependent Claim
39 words
The battery separator of claim 16, wherein the water swellable vinyl alcohol long fiber and the nonwater swellable long fiber have a denier of from about 1 to about 12 and length from about 0.25 to about 1.5 inches.
Claim 23
Dependent Claim
94 words
An alkaline battery comprising one or more positive electrodes, one or more negative electrodes, an alkaline based electrolyte solution and a sheet material for use as a separator or interseparator comprised of from about 30 to about 70 weight percent of the sheet material of synthetic polyolefin pulp, from about 15 to about 65 weight percent of the sheet material of inorganic alkali resistant filler, and from about 1 to about 35 weight percent of the sheet material of a long synthetic fiber, at least some of which is water swellable vinyl alcohol polymer.
Claim 24
Dependent Claim
94 words
An alkaline battery comprising one or more positive electrodes, one or more negative electrodes, an alkaline based electrolyte solution and a sheet material for use as a separator or interseparator comprised of from about 30 to about 70 weight percent of the sheet material of synthetic polyolefin pulp, from about 15 to about 65 weight percent of the sheet material of inorganic alkali resistant filler, and from about 1 to about 35 weight percent of the sheet material of a long synthetic fiber, at least some of which is water swellable vinyl alcohol polymer.
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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) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |