DISPERSION

1 . A dispersion comprising a fluorine-containing polymer and a liquid medium, wherein

the fluorine-containing polymer comprises

a repeating unit derived from a fluorine-containing monomer (a) having a Q value of 2.0 or more and comprising a fluoroalkyl group, and

a repeating unit derived from a chloride monomer (b) that is at least one selected from vinyl chloride and vinylidene chloride, and

the dispersion has a concentration of the unreacted chloride monomer (b) of 2.0 ppm or less.

2 . The dispersion according to claim 1 , wherein

the fluorine-containing monomer (a) is a compound represented by a formula:

CH 2 ═C(—X)—C(═O)—Y—Z—R f

wherein X is a halogen atom;

Y is —O— or —NH—;

Z is a direct bond or a divalent organic group; and

Rf is a fluoroalkyl group having 1 to 20 carbon atoms.

3 . The dispersion according to claim 2 , wherein X is a chlorine atom.

4 . The dispersion according to claim 2 , wherein Rf is a perfluoroalkyl group having 3 to 6 carbon atoms.

5 . The dispersion according to claim 1 , wherein an amount of the repeating unit derived from the chloride monomer (b) is less than 25% by weight relative to the fluorine-containing polymer.

6 . The dispersion according to claim 1 , wherein the fluorine-containing polymer further comprises a repeating unit derived from a hydrocarbon group-containing monomer (c) represented by a formula:

CH 2 ═CA 21 -C(═O)—O-A 22   (c)

wherein A 21 is a hydrogen atom, a monovalent organic group, or a halogen atom, and A 22 is a hydrocarbon group having 2 to 40 carbon atoms.

7 . The dispersion according to claim 6 , wherein the fluorine-containing polymer comprises

a repeating unit derived from a long-chain hydrocarbon group-containing monomer (c1) in which A 22 in formula (c) is an acyclic aliphatic hydrocarbon group having 12 to 30 carbon atoms.

8 . The dispersion according to claim 6 , wherein a total amount of the repeating unit derived from the fluorine-containing monomer (a), the repeating unit derived from the chloride monomer (b), and the repeating unit derived from the hydrocarbon group-containing monomer (c) is 90% by weight or more relative to the fluorine-containing polymer.

9 . The dispersion according to claim 1 , wherein the fluorine-containing polymer further comprises a repeating unit derived from a crosslinkable monomer (d) having at least two selected from the group consisting of a reactive group and an olefinic carbon-carbon double bond.

10 . The dispersion according to claim 9 , wherein an amount of the repeating unit derived from the fluorine-containing monomer (a) is 25% by weight or more relative to the fluorine-containing polymer, and an amount of the repeating unit derived from the crosslinkable monomer (d) is 10% by weight or less relative to the fluorine-containing polymer.

11 . The dispersion according to claim 1 , wherein the concentration of the unreacted chloride monomer (b) is 1.0 ppm or less.

12 . The dispersion according to claim 1 , wherein the liquid medium comprises at least 30% by weight or more of water.

13 . A method for producing a dispersion, comprising:

(i) copolymerizing a fluorine-containing monomer (a) comprising a fluoroalkyl group and having a Q value of 2.0 or more in a Q-e scheme, and a chloride monomer (b) that is at least one selected from vinyl chloride and vinylidene chloride in a liquid medium to obtain a polymerization solution comprising a fluorine-containing polymer, and

(ii) reducing a concentration of the unreacted chloride monomer (b) in the polymerization solution obtained to 2.0 ppm or less.

14 . A method for producing a treated object, comprising applying the dispersion according to claim 1 to a substrate.