Patent US4238303A successfully refreshed from Google Patents.
US4238303A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm modifier for chlor-alkali cell
Assignee: EIDP Inc
•
Filing: 1978-08-14
•
Granted: 1980-12-09
•
Expires: 1998-08-14
Abstract
Abstract Magnesium compounds, such as magnesium oxide or hydroxide, at least partially reacted with fluoropolymer containing carboxyl ions, carboxylic acid or carbonyl fluoride functional groups provide compositions which are useful as modifiers for asbestos diaphragms for chlor-alkali cells to reduce the voltage and increase the efficiency of such cells.
Inventors
- 👤 James C. Fang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:09
CPC Classifications
C; C25; C25B; C25B13/00; C25B13/04; C08; C08F; C08F8/00; C08F8/42; C25B13/05; C25B13/06; C25B13/08
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
86 words
A composition of matter comprising at least one magnesium compound and a fluoropolymer, said magnesium compound being at least partially reacted with said fluoropolymer, said magnesium compound being selected from magnesium oxide, hydroxide, carbonate, oxyhalide and hydroxyhalide, wherein the halide is at least one of fluorine and chlorine, and said fluoropolymer containing functional groups of carboxyl ions, carboxylic acid or carbonyl fluoride or combinations thereof and optionally olefinic double bonds, and having an equivalent weight for each such functional group of not more than about 25,000.
Claim 2
Dependent Claim
86 words
A composition of matter comprising at least one magnesium compound and a fluoropolymer, said magnesium compound being at least partially reacted with said fluoropolymer, said magnesium compound being selected from magnesium oxide, hydroxide, carbonate, oxyhalide and hydroxyhalide, wherein the halide is at least one of fluorine and chlorine, and said fluoropolymer containing functional groups of carboxyl ions, carboxylic acid or carbonyl fluoride or combinations thereof and optionally olefinic double bonds, and having an equivalent weight for each such functional group of not more than about 25,000.
Claim 3
Dependent Claim
19 words
The composition of claim 1 in which the fluoropolymer contains functional groups of both carboxylic acid and carbonyl fluoride.
Claim 4
Dependent Claim
15 words
The composition of claim 1 in which the fluoropolymer contains functional groups of carboxyl ions.
Claim 5
Dependent Claim
16 words
The composition of claim 1 in which the equivalent weight is not more than about 10,000.
Claim 6
Dependent Claim
25 words
The composition of claim 1 in which the weight ratio of said magnesium compound to said fluoropolymer is in the range of 1:12 to 5:1.
Claim 7
Dependent Claim
20 words
The composition of claim 5 in which the weight ratio of said magnesium compound to said fluoropolymer is about 1.1:1.
Claim 8
Dependent Claim
17 words
The composition of claim 1 in which the fluoropolymer is a perfluorocarbon polymer containing said functional groups.
Claim 9
Dependent Claim
20 words
The composition of claim 2 in which the fluoropolymer is a copolymer, by weight, of 95-5% tetrafluoroethylene and 5-95% hexafluoropropylene.
Claim 10
Dependent Claim
17 words
The composition of claim 8 in which the copolymer contains, by weight, 95-97% tetrafluoroethylene and 25-5% hexafluoropropylene.
Claim 11
Dependent Claim
18 words
The composition of claim 9 in which the copolymer contains, by weight, about 85% tetrafluoroethylene and 15% hexafluoropropylene.
Claim 12
Dependent Claim
20 words
The composition of claim 1 in which the molecular weight of the fluoropolymer is in the range of about 1000-100,000.
Claim 13
Dependent Claim
20 words
The composition of claim 11 in which the molecular weight of the fluoropolymer is in the range of about 2000-50,000.
Claim 14
Dependent Claim
20 words
The composition of claim 12 in which the molecular weight of the fluoropolymer is in the range of about 9000-20,000.
Claim 15
Dependent Claim
56 words
The composition of claim 1 in which the fluoropolymer is a perfluorocarbon polymer containing said functional groups and is a copolymer containing, by weight, about 85% tetrafluoroethylene and 15% hexafluoropropylene, said copolymer has a molecular weight in the range of about 9000-20,000, and the weight ratio of said magnesium compound to said fluoropolymer is about 1.1:1.
Claim 16
Dependent Claim
43 words
A method for producing the composition of claim 1 wherein a fluoropolymer is subjected to about 1-100 MRads of ionizing radiation in an oxygen-containing medium to produce said functional groups, and said fluoropolymer is mixed with said magnesium compound and permitted to react.
Claim 17
Dependent Claim
17 words
The method of claim 15 wherein the fluoropolymer is subjected to about 10-75 MRads of ionizing radiation.
Claim 18
Dependent Claim
17 words
The method of claim 16 wherein the fluoropolymer is subjected to about 20-50 MRads of ionizing radiation.
Claim 19
Dependent Claim
27 words
The method of claim 15 wherein the ionizing radiation is in the form of accelerated electrons having an energy level in the range of about 0.2-5 MeV.
Claim 20
Dependent Claim
27 words
The method of claim 18 wherein the ionizing radiation is in the form of accelerated electrons having an energy level in the range of about 2 MeV.
Claim 21
Dependent Claim
24 words
The method of claim 15 wherein at least 2% by weight of the magnesium compound, based on the fluoropolymer, is present during the irradiation.
Claim 22
Dependent Claim
17 words
The method of claim 15 wherein the magnesium compound is mixed with the fluoropolymer after said irradiation.
Claim 23
Dependent Claim
12 words
The method of claim 15 wherein the irradiation is conducted in air.
Claim 24
Dependent Claim
43 words
A method for producing the composition of claim 14 wherein a fluoropolymer is subjected to about 1-1000 MRads of ionizing radiation in an oxygen-containing medium to produce said functional groups, and said fluoropolymer is mixed with said magnesium compound and permitted to react.
Claim 25
Dependent Claim
54 words
A method for producing the composition of claim 1 wherein a fluoropolymer is heated in an oxygen-containing medium to produce said functional groups and said fluoropolymer is mixed with said magnesium compound and permitted to react, the heating being adequate to thermally degrade said fluoropolymer to less than half of its initial molecular weight.
Claim 26
Dependent Claim
21 words
An aqueous dispersion of the composition of claim 1 which also contains surfactant in an amount effective to disperse the composition.
Claim 27
Dependent Claim
17 words
The aqueous dispersion of claim 25 having a solids content of up to about 30% by weight.
Claim 28
Dependent Claim
15 words
The aqueous dispersion of claim 26 having a solids content of about 20% by weight.
Claim 29
Dependent Claim
21 words
An aqueous dispersion of the composition of claim 15 which also contains surfactant in an amount effective to disperse the composition.
Claim 30
Dependent Claim
17 words
The aqueous dispersion of claim 28 having a solids content of up to about 30% by weight.
Claim 31
Dependent Claim
15 words
The aqueous dispersion of claim 29 having a solids content of about 20% by weight.
Claim 32
Dependent Claim
56 words
A composition suitable for producing an improved diaphragm for a chlor-alkali cell comprising a composition of claim 25 mixed with an aqueous dispersion of at least one type of fiber selected from asbestos and borosilicate fiberglass, said fiber being present in an amount of about 50-95% by weight based on the fluoropolymer plus the magnesium compound.
Claim 33
Dependent Claim
27 words
The composition of claim 31 in which the asbestos is present in an amount of about 55-65% by weight based on the fluoropolymer plus the magnesium compound.
Claim 34
Dependent Claim
27 words
The composition of claim 31 in which the asbestos is present in an amount of about 60% by weight based on the fluoropolymer plus the magnesium compound.
Claim 35
Dependent Claim
12 words
The composition of claim 31 in which the selected fiber is asbestos.
Claim 36
Dependent Claim
13 words
The composition of claim 34 in which the selected fiber is chrysotile asbestos.
Claim 37
Dependent Claim
31 words
A modified asbestos diaphragm for a chlor-alkali cell comprising the composition of claim 31 in which the selected fiber is asbestos, which composition has been deposited on a substrate and sintered.
Claim 38
Dependent Claim
20 words
A modified asbestos diaphragm for a chlor-alkali cell comprising asbestos and a composition made by the method of claim 15.
Claim 39
Dependent Claim
20 words
A modified asbestos diaphragm for a chlor-alkali cell comprising asbestos and a composition made by the method of claim 24.
Claim 40
Dependent Claim
20 words
A process of making a diaphragm of claim 36 by depositing said composition on a substrate and sintering said composition.
Claim 41
Dependent Claim
20 words
An electrolytic process for producing chlorine by passing electric current through a chlor-alkali cell having a diaphragm of claim 34.
Claim 42
Dependent Claim
9 words
The composition of claim 1 which includes magnesium oxide.
Claim 43
Dependent Claim
9 words
The composition of claim 1 which includes magnesium hydroxide.
Claim 44
Dependent Claim
9 words
The composition of claim 1 which includes magnesium carbonate.
Claim 45
Dependent Claim
9 words
The composition of claim 1 which includes magnesium oxychloride.
Claim 46
Dependent Claim
9 words
The composition of claim 1 which includes magnesium hydroxychloride.
References Cited (Backward Citations)
US2698788A
Cited
US2962415A
Cited
US3116226A
Cited
US3238056A
Cited
US3144379A
Cited
GB1286859A
Cited
US3694281A
Cited
US4070257A
Cited
US3853721A
Cited
US3965284A
Cited
US3945910A
Cited
US3928166A
Cited
US4007059A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |