US4224393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery separator
Assignee: Daramic LLC
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Filing: 1979-05-10
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Granted: 1980-09-23
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Expires: 1999-05-10
Abstract
Abstract A battery separator, and a method of forming the same, which exhibits good electrical conductivity and a high degree of inhibition to dendrite formation, is in the form of a thin sheet formed from a substantially uniform mixture of a thermoplastic rubber and a filler in a volume ratio of from about 1:0.15 to 1:0.6. The thermoplastic rubber is preferably a styrene/elastomer/styrene block copolymer.
Inventors
- 👤 Stewart C. Feinberg
- 👤 Christian B. Lundsager
- 👤 Joseph T. Lundquist, Jr.
- 👤 Robert A. Balouskus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:07
CPC Classifications
H; H01; H01M; H01M50/00; H01M50/40; H01M50/409; H01M50/449; H01M50/411; H01M50/414; H01M50/489; H01M2300/00; H01M2300/0002; H01M2300/0005; H01M50/491; H01M50/494; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
79 words
A battery separator having high electrical conductivity and inhibition to dendrite formation comprising a substantially uniform sheet formed from a substantially uniform mixture of a thermoplastic rubber and an inert filler having an average particle size of from about 0.01 to 10 microns, the volume ratio of the thermoplastic rubber to filler is from 1:0.15 to 1:0.6 said thermoplastic rubber being a styrene/elastomer/styrene block copolymer having styrene present in from about 15 to 40 weight percent of the copolymer.
Claim 2
Dependent Claim
79 words
A battery separator having high electrical conductivity and inhibition to dendrite formation comprising a substantially uniform sheet formed from a substantially uniform mixture of a thermoplastic rubber and an inert filler having an average particle size of from about 0.01 to 10 microns, the volume ratio of the thermoplastic rubber to filler is from 1:0.15 to 1:0.6 said thermoplastic rubber being a styrene/elastomer/styrene block copolymer having styrene present in from about 15 to 40 weight percent of the copolymer.
Claim 3
Dependent Claim
53 words
The separator of claim 1 wherein the thermoplastic rubber is selected from styrene/ethylene-butylene/styrene, styrene/isoprene/styrene, or styrene/butadiene/styrene block copolymers or mixtures thereof; said copolymers having a melt index of less than about 10, a number average molecular weight of from about 40,000 to 100,000 for the elastomer, and 10,000 to 20,000 for the styrene.
Claim 4
Dependent Claim
24 words
The battery separator of claim 1 or 2 wherein the volume ratio of the thermoplastic rubber to filler is from about 1:0.25 to 1:0.4.
Claim 5
Dependent Claim
24 words
The battery separator of claim 1 or 2 wherein the filler is selected from a metal oxide, a metal hydroxide or a metal carbonate.
Claim 6
Dependent Claim
20 words
The battery separator of claim 3 wherein the filler is selected from titanium dioxide or aluminum oxide of mixtures thereof.
Claim 7
Dependent Claim
15 words
The battery separator of claim 3 wherein the sheet is less than 10 mil thick.
Claim 8
Dependent Claim
31 words
The battery separator of claim 6 comprising a laminate structure of multiple layers of said microporous sheet material, said laminate structure having a combined thickness of less than about 10 mil.
References Cited (Backward Citations)
US3161547A
Cited
US3351495A
Cited
US3585081A
Cited
US3967978A
Cited
US3875270A
Cited
US4085241A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |