US3945910A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm for an electrolysis cell
Assignee: Solvay SA
•
Filing: 1974-06-13
•
Granted: 1976-03-23
•
Expires: 1994-06-13
Abstract
Abstract Diaphragms for a cell, in which the electrolysis of an aqueous solution of an alkali metal is carried out, having good permeability, shape and dimensional stability and good wettability characteristics with respect to the electrolyte are disclosed as well as a method for the manufacture thereof. The diaphragms are composed of a mixed sheet of a substantially homogeneous mixture of amphibole asbestos fibers and polyvinylidene fluoride fibrils connected together. To manufacture the diaphragms, an intimate mixture of polyvinylidene fluoride fibrils and amphibole asbestos is formed into a sheet and the sheet is heated to cause surface fusion of the fibrils.
Inventors
- 👤 Jean De Ceuster
- 👤 Bruno Grassi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:09
CPC Classifications
B; B32; B32B; B32B19/00; B32B19/02; C; C25; C25B; C25B13/00; C25B13/04; B32B19/04; B32B19/08; C25B13/05; C25B13/06; B32B2250/00; B32B2250/02; B32B2250/03; B32B2250/40; B32B2315/00; B32B2315/12; B32B2457/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
83 words
A diaphragm for a cell for the electrolysis of an aqueous solution of an alkali metal halide comprising a mixed sheet formed of a substantially homogeneous mixture of fibers of amphibole asbestos and fibrils of polyvinylidene fluoride connected together, said fibrils having a three-dimensional network structure, a length of about 0.5 to 50 mm., a thickness of about 0.01 to 5 and a specific surface area greater than 1 m. 2 /g. and forming ribbons having a thickness of less than 4 u.
Claim 2
Dependent Claim
83 words
A diaphragm for a cell for the electrolysis of an aqueous solution of an alkali metal halide comprising a mixed sheet formed of a substantially homogeneous mixture of fibers of amphibole asbestos and fibrils of polyvinylidene fluoride connected together, said fibrils having a three-dimensional network structure, a length of about 0.5 to 50 mm., a thickness of about 0.01 to 5 and a specific surface area greater than 1 m. 2 /g. and forming ribbons having a thickness of less than 4 u.
Claim 3
Dependent Claim
14 words
A diaphragm according to claim 1, wherein said asbestos fibers comprise fibers of crocidolite.
Claim 4
Dependent Claim
15 words
A diaphragm according to claim 1, wherein the said asbestos fibers comprise fibers of anthophyllite.
Claim 5
Dependent Claim
21 words
A diaphragm according to claim 1, wherein said mixed sheet comprises 10% to 80% by weight of fibrils of polyvinylidene fluoride.
Claim 6
Dependent Claim
19 words
A diaphragm according to claim 4, wherein said mixed sheet comprises 20% to 50% by weight of said fibrils.
Claim 7
Dependent Claim
33 words
A diaphragm according to claim 1, wherein the weight of said mixed sheet is between about 350 and about 650 g./m. 2 and the thickness between about 0.3 mm. and about 0.8 mm.
Claim 8
Dependent Claim
18 words
A diaphragm according to claim 1, wherein said mixed sheet is bonded to a sheet of chrysotile asbestos.
Claim 9
Dependent Claim
51 words
A diaphragm according to claim 7, wherein said sheet of crysotile asbestos has a thickness between about 0.2 mm. and about 0.5 mm. and a permeability between about 0.8 and about 3.5 liters per hour per dm. 2 of diaphragm surface at a head 1 dm. of aqueous sodium chloride solution.
Claim 10
Dependent Claim
25 words
A diaphragm according to claim 1, wherein said mixed sheet is sandwiched between two sheets of chrysotile asbestos and is bonded to said two sheets.
Claim 11
Dependent Claim
51 words
A diaphragm according to claim 9, wherein each sheet of crysotile asbestos has a thickness between about 0.2 mm. and about 0.5 mm. and a permeability between about 0.8 and about 3.5 liters per hours per dm. 2 of diaphragm surface at a head 1 dm. of aqueous sodium chloride solution.
Claim 12
Dependent Claim
50 words
A diaphragm according to claim 1, wherein said asbestos fibers are selected from anthophyllite and crocidolite fibers in an amount of 40-80% by weight and in which, the thickness of said diaphragm is from about 0.5 to 0.75 mm. and the weight is about 390 to 560 g./m. 2 .
Claim 13
Dependent Claim
14 words
A diaphragm according to claim 1 wherein the surface of said fibrils is fused.
References Cited (Backward Citations)
US3097990A
Cited
US3235473A
Cited
US3282875A
Cited
US3441472A
Cited
US3505200A
Cited
US3583891A
Cited
US3694281A
Cited
US3702267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |