Asahi Kasei Kogyo Kabushiki Kaisha

Mikio Ebisawa

Kyoji Kimoto

Hirotsugu Miyauchi

Toshioki Hane

Jukichi Ohmura

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 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

A method for producing a fluorinated copolymer membrane comprising a first layer made from a fluorinated copolymer having pendant sulfonylchloride groups and a second layer made from a fluorinated copolymer having sulfonylfluoride groups. The membrane is treated with a reducing agent to introduce carboxylic acid groups onto the surface of said first layer. The membrane may be used as a cation exchange membrane. If necessary, a supporting material may be embedded in the second layer.

Method for producing a fluorinated copolymer membrane

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.

Growing community of inventors

Kanagawa, Japan

Mikio Ebisawa