Asahi Kasei Kogyo Kabushiki Kaisha

Asahi Kasei Kabushiki Kaisha

Hirotsugu Miyauchi

Kyoji Kimoto

Toshioki Hane

Jukichi Ohmura

Mikio Ebisawa

Yasumichi Yamakoshi

Itaru Watanabe

Maomi Seko

Sakae Tsushima

Mitsunobu Fukumoto

Masato Hamada

Yoshinori Masuda

Fumihiko Yamamoto

Hiroshi Sagami

Shigeo Yokoyama

Naomi Seko

A novel fluorinated copolymer is prepared by copolymerization of a fluorinated olefin with a novel sulfur containing fluorinated vinylether of the formula: ##STR1## wherein k is 0 or 1 and l is an integer of 3 to 5, which is prepared from starting materials which are also novel. Said copolymer is useful for preparation of a fluorinated cation exchange membrane having carboxylic acid groups and/or sulfonic acid groups which can be used advantageously in electrolysis of an aqueous alkali metal halide solution with improved electrolysis performance.

Fluorosulfonylperfluoroalkyl compounds

A novel fluorinated cation exchange membrane containing carboxylic acid groups and sulfonic acid groups, both in the form of a specific pendant structure, the carboxylic acid groups being at least 20% on one surface of the membrane and gradually decreasing toward the innerside of the membrane, which membrane is useful in electrolysis of an aqueous alkali metal halide solution with advantageously stable performance for a long term under more severe operational conditions than those conventionally used. The membrane can be prepared from a novel copolymer of a fluorinated olefin with a novel sulfur containing fluorinated vinylether of the formula: ##STR1## wherein k is 0 or 1, l is an integer of 3 to 5, Z is --S-- or --SO.sub.2 -- and R is C.sub.1 -C.sub.10 alkyl, an aryl, C.sub.1 -C.sub.10 perfluoroalkyl.

Intermediates for fluorinated cation exchange membrane

A novel fluorinated cation exchange membrane containing carboxylic acid groups and sulfonic acid groups, both in the form of a specific pendant structure, the carboxylic acid groups being at least 20% on one surface of the membrane and gradually decreasing toward the innerside of the membrane, which membrane is useful in electrolysis of an aqueous alkali metal halide solution with advantageously stable performance for a long term under more severe operational conditions than those conventionally used. The membrane can be prepared from a novel copolymer of a fluorinated olefin with a novel sulfur containing fluorinated vinylether of the formula: ##STR1## wherein k is 0 or 1, l is an integer of 3 to 5, Z is --S-- or --SO.sub.2 -- and R is C.sub.1 -C.sub.10 alkyl, an aryl, Cl or C.sub.1 -C.sub.10 perfluoroalkyl. Acyl fluorides, which are the precursors of the fluorinated olefin ethers, are also disclosed.

Fluorinated ether acyl fluorides having alkylthio or alkylsulfone groups

Perfluoro vinyl ethers

A novel fluorinated copolymer is prepared by copolymerization of a fluorinated olefin with a novel sulfur containing fluorinated vinylether of the formula: ##STR1## wherein k is 0 or 1 and l is an integer of 3 to 5, which is prepared from starting materials, which are also novel. Said copolymer is useful for preparation of a fluorinated cation exchange membrane having carboxylic acid groups and/or sulfonic acid groups which can be used advantageously in electrolysis of an aqueous alkali metal halide solution with improved electrolysis performance.

Perfluorinated fluorosulfonylalkyleneoxy-2-propanoyl fluoride and

A novel fluorinated cation exchange membrane containing carboxylic acid groups and sulfonic acid groups, both in the form of a specific pendant structure, the carboxylic acid groups being at least 20% on one surface of the membrane and gradually decreasing toward the innerside of the membrane, which membrane is useful in electrolysis of an aqueous alkali metal halide solution with advantageously stable performance for a long term under more severe operational conditions than those conventionally used. The membrane can be prepared from a novel copolymer of a fluorinated olefin with a novel sulfur containing fluorinated vinylether of the formula: ##STR1## wherein k is 0 or 1, l is an integer of 3 to 5, Z is --S-- or --SO.sub.2 -- and R is C.sub.1 -C.sub.10 alkyl, an aryl, Cl or C.sub.1 -C.sub.10 perfluoroalkyl.

Fluorinated vinyl ether compounds and process for producing the same

A cation exchange membrane prepared from a blend of two different fluorinated polymers, each containing cation exchange groups selected from carboxylic acid groups, sulfonamide groups, N-monosubstituted sulfonamide groups and sulfonic acid groups, having different exchange capacities with a difference of at least 200 therebetween in terms of equivalent weight. This membrane has been found to be useful in the electrolysis of an aqueous alkali metal halide solution and can give improved results in such an electrolysis.

Cation exchange membrane

A fluorinated cation exchange membrane characterized by the gradual decrease in proportion of the density of carboxylic acid and/or carboxylate groups relative to the total density of carboxylic acid and/or carboxylate groups and sulfonic acid and/or sulfonate groups from one surface of the membrane to the other surface or an internal plane therewithin. The cation exchange membrane of the present invention can be prepared by treating one surface of a membrane comprising a fluorocarbon polymer containing pendant groups of the formula:

Fluorinated cation exchange membrane and process for preparing the same

Fluorinated cation exchange membrane

Novel fluorinated cation exchange membrane and process for producing the

A novel fluorinated copolymer is prepared by copolymerization of a fluorinated olefin with a novel sulfur containing fluorinated vinyl ether of the formula: ##STR1## wherein k is 0 or 1 and l is an integer of 3 to 5, which is prepared from starting materials which are also novel. Said copolymer is useful for preparation of a fluorinated cation exchange membrane having carboxylic acid groups and/or sulfonic acid groups which can be used advantageously in electrolysis of an aqueous alkali metal halide solution with improved electrolysis performance.

Novel fluorinated copolymer with tridihydro fluorosulfonyl fluoride

In performing melt processing of a fluorinated polymer which contains such pendant functional groups as sulfonic acid, carboxylic acid, sulfonamide and salts thereof, an aqueous medium is allowed to be present in the polymer to improve its melt-flow characteristic. Excellent heat sealing can be effected without degradation of the polymer. This method is particularly suitable for repairing the damaged ion-exchange membranes of fluorinated polymers used in the electrolysis of sodium chloride to enable elongation of their life to a great economical advantage.

Melt processing of fluorinated polymers

An electrolytic cell having anode and cathode chambers separated by a cation exchange membrane comprising a fluorocarbon polymer containing pendant carboxylic acid or salt groups of the formula ##STR1## wherein R is a group containing perfluoroalkyl or perfluoroalkoxy having 1 to 5 carbon atoms and M is hydrogen, an alkali or alkaline earth metal or ammonium as a surface stratum on the cathode side of the membrane. The fluorocarbon polymer may also contain sulfonic acid groups of the formula ##STR2##

Electrolysis of aqueous alkali metal halide solution

Cation exchange membrane comprising a fluorocarbon polymer characterized by the presence of pendant carboxylic acid groups of the formula -- OCF.sub.2 COOH -- and derivatives thereof.

Cation exchange membrane preparation and use thereof

A fluorocarbon polymer membrane having pendant sulfonamide groups is first treated with anion radicals and then hydrolyzed for conversion into a cation exchange membrane having carboxylic groups and sulfonic acid groups.

Growing community of inventors

Tokyo, Japan

Hirotsugu Miyauchi