US4025401A
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US
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Method for diaphragm electrolysis of alkali metal halides
Assignee: Maruzen Petrochemical Co Ltd
•
Filing: 1975-09-24
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Granted: 1977-05-24
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Expires: 1995-09-24
Abstract
Abstract A method for diaphragm electrolysis of an alkali metal halides which comprises electrolyzing an alkali metal halide solution by passing an electric current through an anode compartment and a cathode compartment of an electrolytic cell containing the alkali metal halide solution with an ion-exchange membrane of a graft copolymer of a polyolefin main chain and a side chain composed mainly of dihydroxystyrene and grafted to the polyolefin main chain separating the anode compartment and the cathode compartment.
Inventors
- 👤 Hiroshi Fujiwara
- 👤 Kinya Jawara
- 👤 Kaoru Miyoshi
- 👤 Makoto Mukai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:16
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08F; C08F255/00; C08F257/00
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
78 words
A method for diaphragm electrolysis of an alkali metal halide which comprises electrolyzing an alkali metal halide solution by passing an electric current through an anode compartment and a cathode compartment of an electrolytic cell containing the alkali metal halide solution with an ion-exchange membrane of a graft copolymer of a polyolefin main chain and a side chain composed mainly of a dihydroxystyrene and grafted to said polyolefin main chain separating the anode compartment and the cathode compartment.
Claim 2
Independent Claim
78 words
A method for diaphragm electrolysis of an alkali metal halide which comprises electrolyzing an alkali metal halide solution by passing an electric current through an anode compartment and a cathode compartment of an electrolytic cell containing the alkali metal halide solution with an ion-exchange membrane of a graft copolymer of a polyolefin main chain and a side chain composed mainly of a dihydroxystyrene and grafted to said polyolefin main chain separating the anode compartment and the cathode compartment.
Claim 3
Dependent Claim
11 words
The method of claim 1, wherein said graft copolymer is crosslinked.
Claim 4
Dependent Claim
20 words
The method of claim 2, wherein said graft copolymer is crosslinked with a difunctional compound reactive with phenolic hydroxyl groups.
Claim 5
Dependent Claim
26 words
The method of claim 3, wherein said difunctional compound is used in an amount of about 0.01 to 0.5 equivalent per equivalent of phenolic hydroxyl group.
Claim 6
Dependent Claim
18 words
The method of claim 3, wherein said difunctional compound is a diepoxide, a diisocyanate or an acid dihalide.
Claim 7
Dependent Claim
45 words
The method of claim 3, wherein said difunctional compound is ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, cyclohexane diol diglycidyl ether, an epoxy resin, hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, hexahydrotolylene diisocyanate, adipoyl dichloride, terephthaloyl dichloride or hexahydroterephthaloyl dichloride.
Claim 8
Dependent Claim
17 words
The method of claim 2, wherein said graft copolymer is crosslinked with an organic sulfonic acid compound.
Claim 9
Dependent Claim
10 words
The method of claim 7, wherein said compound is divinylbenzene.
Claim 10
Dependent Claim
30 words
The method of claim 7, wherein said compound is isoprene, butadiene, cyclopentadiene, ethylidene norbornene, a diol ester of acrylic acid or methacrylic acid, or a divinyl ester of adipic acid.
Claim 11
Dependent Claim
25 words
The method of claim 2, wherein said graft copolymer is crosslinked with a polyene compound containing at least two polymerizable double bonds in the molecule.
Claim 12
Dependent Claim
25 words
The method of claim 10, wherein the amount of said polyene compound is about 0.5 to 100% by weight based on the polyolefin main chain.
Claim 13
Dependent Claim
22 words
The method of claim 1, including pre-treating said ion-exchange membrane with a solution of an alkali metal hydroxide prior to the electrolysis.
Claim 14
Dependent Claim
64 words
The method of claim 12, wherein said pre-treating comprises contacting said ion-exchange membrane with an aqueous solution of an alkali metal hydroxide; an aqueous solution of an alkali metal hydroxide additionally containing an organic solvent capable of being uniformly mixed with said aqueous solution and capable of swelling said ion-exchange membrane; or a solution of an alkali metal hydroxide in a lower aliphatic alcohol.
Claim 15
Dependent Claim
61 words
The method of claim 13, wherein the concentration of said alkali metal hydroxide in said alkali metal hydroxide solution is about 0.1 to 12N and the contacting of said ion-exchange membrane with said alkali metal hydroxide solution is conducted at a temperature of about room temperature to about 90° C. for a period of about 30 minutes to about 5 hours.
Claim 16
Dependent Claim
19 words
The method of claim 1, wherein said polyolefin is an aliphatic polymer, an aromatic polymer or an alicyclic polymer.
Claim 17
Dependent Claim
10 words
The method of claim 15, wherein said polyolefin is polyethylene.
Claim 18
Dependent Claim
10 words
The method of claim 15, wherein said polyolefin is polypropylene.
Claim 19
Dependent Claim
10 words
The method of claim 15, wherein said polyolefin is polystyrene.
Claim 20
Dependent Claim
23 words
The method of claim 1, wherein said side chain comprises a dihydroxystyrene and a polyene compound containing at least two polymerizable double bonds.
Claim 21
Dependent Claim
21 words
The method of claim 19, wherein the weight ratio of the dihydroxystyrene to the polyene compound is about 200:1 to 1:1.
Claim 22
Dependent Claim
11 words
The method of claim 1, wherein said graft copolymer is sulfonated.
Claim 23
Dependent Claim
21 words
The method of claim 21, wherein said graft copolymer contains about 0.5 to 2 sulfonic acid groups introduced per dihydroxystyrene unit.
Claim 24
Dependent Claim
22 words
The method of claim 1, wherein the dihydroxystyrene content is about 5 to 500% by weight based on the polyolefin main chain.
References Cited (Backward Citations)
US2967807A
Cited
US3304272A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-23 | 1980-11-22 | 1981-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-23 | 1984-11-22 | 1985-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-23 | 1988-11-22 | 1989-05-24 | $7700.00 | Window Closed / Lapsed |