Method for producing fluoropolymer powder
AssigneeDaikin Industries, Ltd.
InventorsChiaki Okui, Hirotoshi Yoshida, Hiroyuki Sato, Kenji Ichikawa, Taketo Kato, Taku Yamanaka
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Abstract
A method for producing a fluoropolymer powder including (A1) adding, to a fluoropolymer aqueous dispersion obtained by polymerization using a carboxylic acid type hydrocarbon surfactant, and an acid to adjust a pH to 4.0 or less and cause coagulation to thereby obtain a wet fluoropolymer powder containing a fluorine-containing compound represented by the following general formula (1A), and (B1) heat-treating the wet fluoropolymer powder at a temperature higher than 150° C. and lower than 240° C.: General Formula (1A): H—(CF2)m—COOH wherein m is 3 to 19.
Claims9
A method for producing a fluoropolymer powder, comprising:
- (A1) adjusting a pH of a fluoropolymer aqueous dispersion, obtained by polymerization using a carboxylic acid hydrocarbon surfactant, to 4.0 or less by adding an acid and to cause coagulation to thereby obtain a wet fluoropolymer powder containing a fluorine-containing compound represented by the following formula (1A);
- H—(CF2)m—COOH, Formula (1A):
- wherein m is 3 to 19;
- and
- (B1) heat-treating the wet fluoropolymer powder at a temperature higher than 150° C. and lower than 240° C. in hot air circulation, thereby reducing an amount of the fluorine-containing compound in the fluoropolymer powder.
A method for producing a fluoropolymer powder, comprising:
- (A2) adjusting a pH of a fluoropolymer aqueous dispersion, obtained by polymerization using an aliphatic carboxylic acid hydrocarbon surfactant, to 4.0 or less by adding an acid and to cause coagulation to thereby obtain a wet fluoropolymer powder containing a fluorine-containing compound represented by the following formula (1A):
- H—(CF2)m—COOH Formula (1A):
- wherein m is 3 to 19;
- and
- (B2) heat-treating the wet fluoropolymer powder at a temperature higher than 100° C. in hot air circulation, thereby reducing an amount of the fluorine-containing compound in the fluoropolymer powder.
Dependencies are inferred from the claim text.