US4036729A
Expired / Lapsed
US
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Diaphragms from discrete thermoplastic fibers requiring no bonding or cementing
Assignee: BASF Corp
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Filing: 1975-04-10
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Granted: 1977-07-19
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Expires: 1995-04-10
Abstract
Abstract Diaphragms for electrolytic cells are prepared by depositing onto a cathode screen, discrete thermoplastic fibers. The fibers are highly branched, and which, when deposited form an entanglement or network thereof, which does not require bonding or cementing.
Inventors
- 👤 Arvind S. Patil
- 👤 Eugene Y. Weissman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:41
CPC Classifications
C; C25; C25B; C25B13/00; C25B13/04; C25B13/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
85 words
In an electrolytic cell having a diaphragm deposited on a cathode screen, an improved diaphragm therefor, comprising: an entanglement of highly branched thermoplastic polymeric fibers, the fibers being capable of withstanding the internal conditions of the cell, the fibers being of the type produced by extruding a polymer melt in the presence of an auxiliary liquid medium which shears the melt into the highly branched fibers, and wherein the fibers are entangled to a degree such that they are free of bonding or cementing agents.
Claim 2
Dependent Claim
85 words
In an electrolytic cell having a diaphragm deposited on a cathode screen, an improved diaphragm therefor, comprising: an entanglement of highly branched thermoplastic polymeric fibers, the fibers being capable of withstanding the internal conditions of the cell, the fibers being of the type produced by extruding a polymer melt in the presence of an auxiliary liquid medium which shears the melt into the highly branched fibers, and wherein the fibers are entangled to a degree such that they are free of bonding or cementing agents.
Claim 3
Dependent Claim
26 words
The improvement of claim 1 wherein the branched thermoplastic fiber is selected from the group consisting of polyolefins, polycarbonates, polyesters, polyamides, fluorinated hydrocarbons, and mixtures thereof.
Claim 4
Dependent Claim
14 words
The improvement of claim 2 wherein the branched thermoplastic fiber is a fluorinated hydrocarbon.
Claim 5
Dependent Claim
12 words
The diaphragm of claim 3 wherein the branched thermoplastic fiber is polyvinylidenefluoride.
Claim 6
Dependent Claim
20 words
The improvement of claim 1 wherein the fibers have a diameter of from about one-tenth micron to about forty microns.
Claim 7
Dependent Claim
13 words
The improvement of claim 1 wherein: the electrolytic cell is a chlor-alkali cell.
Claim 8
Dependent Claim
19 words
The improvement of claim 1 wherein the highly branched thermoplastic fibers are utilized in admixture with a wetting agent.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |