US4426272A
Expired / Lapsed
US
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Electrolytic cell vermiculite diaphragms
Assignee: Dow Chemical Co
•
Filing: 1982-05-10
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Granted: 1984-01-17
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Expires: 2002-05-10
Abstract
Abstract Diaphragms for use in electrolytic cells, e.g., chlor-alkali cells, are beneficially prepared using pulverized expanded vermiculite in place of the historically popular asbestos.
Inventors
- 👤 Richard A. Hanmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:38
CPC Classifications
C; C25; C25B; C25B13/00; C25B13/04; C25B13/05
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
30 words
A semi-permeable material for use as a hydraulically-permeable diaphragm in an electrolytic cell, said material consisting essentially of a contiguous sheet of pulverized expanded vermiculite deposited on a foraminous cathode.
Claim 2
Dependent Claim
30 words
A semi-permeable material for use as a hydraulically-permeable diaphragm in an electrolytic cell, said material consisting essentially of a contiguous sheet of pulverized expanded vermiculite deposited on a foraminous cathode.
Claim 3
Dependent Claim
15 words
The contiguous sheet of claim 1 when positioned as a diaphragm in a chlor-alkali cell.
Claim 4
Dependent Claim
32 words
The contiguous sheet of claim 1 wherein the vermiculite comprises particles which prior to being expanded and then pulverized, are of a size not greater than about 16-mesh, U.S. Standard sieve size.
Claim 5
Dependent Claim
18 words
The contiguous sheet of claim 1 wherein there is incorporated therein a minor amount of fibrous polymer reinforcement.
Claim 6
Dependent Claim
18 words
The contiguous sheet of claim 1 wherein there is incorporated therein a minor amount of particulate polymer binder.
Claim 7
Dependent Claim
26 words
The contiguous sheet of claim 1 wherein there is incorporated therein a minor amount of fibrous polymer reinforcement and a minor amount of particulate polymer binder.
Claim 8
Dependent Claim
13 words
The contiguous sheet of claim 4 wherein the fibrous polymer comprises a fluoropolymer.
Claim 9
Dependent Claim
13 words
The contiguous sheet of claim 5 wherein the polymer binder comprises a fluoropolymer.
Claim 10
Independent Claim
69 words
A method for preparing a vermiculite sheet material for use as a diaphragm means in an electrolytic chlorine cell, said method comprising expanding vermiculite particles which are of a size not greater than about 16-mesh, U.S. Standard Seive Size, pulverizing said expanded vermiculite particles, preparing an aqueous dispersion of said pulverized particles, and formng a substantially de-watered, contiguous, diaphragm sheet material from said aqueous dispersion onto a foraminous cathode.
Claim 11
Independent Claim
69 words
A method for preparing a vermiculite sheet material for use as a diaphragm means in an electrolytic chlorine cell, said method comprising expanding vermiculite particles which are of a size not greater than about 16-mesh, U.S. Standard Seive Size, pulverizing said expanded vermiculite particles, preparing an aqueous dispersion of said pulverized particles, and formng a substantially de-watered, contiguous, diaphragm sheet material from said aqueous dispersion onto a foraminous cathode.
Claim 12
Dependent Claim
22 words
The method of claim 9 wherein the aqueous dispersion of vermiculite particles contains a minor amount of binder means for the particles.
Claim 13
Dependent Claim
12 words
The method of claim 10 wherein the binder means comprises a polymer.
Claim 14
Dependent Claim
11 words
The method of claim 11 wherein the polymer is a fluoropolymer.
Claim 15
Dependent Claim
19 words
The method of claim 9 wherein the aqueous dispersion of vermiculite particles contains a minor amount of fibrous material.
Claim 16
Dependent Claim
12 words
The method of claim 13 wherein the fibrous material comprises polymer fibers.
Claim 17
Dependent Claim
11 words
The method of claim 14 wherein the polymer is a fluoropolymer.
Claim 18
Dependent Claim
25 words
The method of claim 9 wherein the aqueous dispersion of vermiculite particles contains a minor amount of binder means a minor amount of fibrous material.
Claim 19
Dependent Claim
17 words
The method of claim 16 wherein the binder means and the fibrous material are comprised of polymers.
Claim 20
Dependent Claim
12 words
The method of claim 17 wherein the polymers are comprised of fluoropolymers.
References Cited (Backward Citations)
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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) | 1987-01-16 | 1987-07-18 | 1988-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-16 | 1991-07-18 | 1992-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-16 | 1995-07-18 | 1996-01-17 | $7700.00 | Window Closed / Lapsed |