Fluoropolymer dispersion and process for producing fluoropolymer dispersion

摘要

A method for producing a fluoropolymer dispersion where a fine particle containing a fluoropolymer is dispersed in an aqueous dispersion medium, the fluoropolymer having a sulfonic acid group, and the method including a polymerization reaction step of emulsion polymerizing a fluorovinyl ether derivative and a fluorine-containing ethylenic monomer to give a fluoropolymer precursor, a hydrolysis step of hydrolyzing, in an aqueous medium, —SO2X1, where X1 represents a halogen atom, which the fluoropolymer precursor has thereby to give the fluoropolymer, the fluorovinyl ether derivative being represented by the following general formula (II):
CF2═CF—O—(CF2CFY1—O)n—(CFY2)m-A1  (II)
wherein Y1, n, Y1, m and A1 are as defined herein, the fluoropolymer precursor having a fluorovinyl ether derivative unit content of 5 to 40 mole percent, and the fluoropolymer dispersion being produced without drying the fluoropolymer precursor and the fluoropolymer.

主权项

1. A method for producing a fluoropolymer dispersion to give the fluoropolymer dispersion where a fine particle comprising a fluoropolymer is dispersed in an aqueous dispersion medium, the fluoropolymer having a sulfonic acid group, the method comprising:
a polymerization reaction step of emulsion polymerizing a fluorovinyl ether derivative and a fluorine-containing ethylenic monomer to give an aqueous dispersion of a fluoropolymer precursor, wherein the fluorovinyl ether derivative being represented by the following general formula (II):
CF2═CF—O—(CF2CFY1—O)n—(CFY2)m-A1  (II)wherein Y1 represents a fluorine atom, a chlorine atom or a perfluoroalkyl group; n represents an integer of 0 to 3, and n atoms/groups of Y1 may be the same or different; Y2 represents a fluorine atom or a chlorine atom; m represents an integer of 1 to 5, and m atoms of Y2 may be the same or different; A1 represents —SO2X1; X1 represents a halogen atom, the fluoropolymer precursor having a fluorovinyl ether derivative unit content of 5 to 40 mole percent; a hydrolysis step of hydrolyzing in the aqueous dispersion —SO2X1, wherein X1 represents a halogen atom which the fluoropolymer precursor has thereby to give the fluoropolymer by adding dropwise an alkali to the aqueous dispersion with 5 to 15% by mass relative to the aqueous medium of the fluoropolymer precursor, wherein the fluoropolymer dispersion is produced without drying the fluoropolymer precursor and the fluoropolymer.