Fluorinated coating material, method for producing fluorinated coating material, coated article and its production method

1. A fluorinated coating material comprising a fluorinated polymer having the following units F, the following units 1 and the following units 2:

units F: at least one type of units selected from the group consisting of units based on CF 3 —CH═CHF and units based on CF 3 —CF═CH 2 ;

units 1: at least one type of units selected from the group consisting of units having a carboxy group, units based on allyl alcohol and units based on a hydroxyalkyl allyl ether;

units 2: at least one type of units selected from the group consisting of units based on a vinyl ether, units based on a vinyl ester, units based on an allyl ether (excluding a hydroxyalkyl allyl ether), units based on an allyl ester and units based on a (meth)acrylic acid ester.

2. The fluorinated coating material according to claim 1 , wherein the units F consist of units based on CF 3 —CH═CHF and units based on CF 3 —CF═CH 2 .

3. The fluorinated coating material according to claim 1 , wherein the content of the units F is from 20 to 80 mol % to all units in the fluorinated polymer.

4. The fluorinated coating material according to claim 1 , wherein the units having a carboxy group are units based on a monomer represented by the formula CHR 11 ═CHR 12 -Q 1 -COOH:

wherein R 11 and R 12 are each independently a hydrogen atom or a C 1-3 alkyl group, and Q 1 is a single bond, a C 1-12 alkylene group or a C 4-12 alkylene group having —C(═O)O—.

5. The fluorinated coating material according to claim 1 , wherein the units having a carboxy group are units having a carboxy group formed by reacting a polycarboxylic acid anhydride with hydroxy groups of a fluorinated polymer having units having a hydroxy group.

6. The fluorinated coating material according to claim 1 , wherein at least a part of the units 2 are at least one type of units selected from the group consisting of units based on a vinyl ether and units based on a vinyl ester, and the total content of the units based on a vinyl ether and the units based on a vinyl ester is from 10 to 50 mol % to all units in the fluorinated polymer.

7. The fluorinated coating material according to claim 1 , which further contains a curing agent, wherein the curing agent is a compound having in one molecule at least two epoxy groups, carbodiimide groups, oxazoline groups or β-hydroxyalkylamide groups.

8. The fluorinated coating material according to claim 1 , which further contains an organic solvent, the fluorinated polymer being dissolved in the organic solvent, and which is used as a solvent-based coating material.

9. The fluorinated coating material according to claim 1 , wherein the fluorinated polymer is powdery, and which is used as a powder coating material.

10. The fluorinated coating material according to claim 9 , wherein the units 2 have a C 4-8 alkyl group represented by the formula —C(Z 21 ) 3 (wherein three Z 21 's are each independently a C 1-5 alkyl group), a C 6-10 cycloalkyl group, a C 6-10 cycloalkylalkyl group, a C 6-10 aryl group or a C 7-12 aralkyl group.

11. The fluorinated coating material according to claim 1 , which further contains water, the fluorinated polymer being dispersed in water, and which is used as an aqueous coating material.

12. The fluorinated coating material according to claim 11 , wherein at least a part of the units 2 have a group represented by the formula —Y 2 —O(M 2 O) n2 R 2 ,

wherein Y 2 is a C 2-12 bivalent saturated hydrocarbon group, M2 is a C 2-4 alkylene group, and at least 50% by the number of n2 M 2 's are ethylene groups, R 2 is a hydrogen atom or an alkyl group having at most 4 carbon atoms, and n2 is an integer of from 8 to 22.

13. A method for producing the fluorinated coating material as defined in claim 11 , which comprises adding a polycarboxylic acid anhydride to an organic solvent solution of the fluorinated polymer having no units having a carboxy group and having units having a hydroxy group, so that they react with each other, to obtain a fluorinated polymer having units having a carboxy group, and replacing the organic solvent with water to disperse the fluorinated polymer in water.

14. A method for producing a coated article, which comprises applying the fluorinated coating material as defined in claim 1 on a substrate to form a coating layer, and curing the coating layer to form a coating film on the substrate.

15. A coated article comprising a substrate and a coating film formed on the substrate from the fluorinated coating material as defined in claim 1 .