Low VOC and high solid fluoropolymer for coating applications
Methods of reducing the release of volatile organic compounds (VOCs) into the Earth's atmosphere during coating operations are provided, as well as a coating composition comprising a carrier and one or more fluorocopolymers. The carrier comprises VOC compounds and the one or more fluorocopolymers is produced by copolymerization of (1) a first monomer selected from the group consisting of hydrofluoroalkenes, (2) a second monomer comprising vinyl ester(s), and (3) a third monomer comprising vinyl ether(s), wherein at least a portion of the vinyl ether monomer is a hydroxyl group-containing vinyl ether, and wherein the one or more fluorocopolymers comprise at least about 70% by weight of the coating composition and the VOC portion of the carrier is not greater than about 30% by weight of the coating composition.
1. A coating composition comprising:
(i) one or more fluorocopolymers formed by copolymerization of monomers comprising:
(1) from about 45 mol % to about 55 mol % of HFO-1234ze, (2A) from about 10 mol % to about 20 mol % of vinyl ester represented by the formula CH 2 ═CR 1 —O(C═O) x R 2 , wherein x is 1, R 1 is hydrogen and R 2 is an unsubstituted branched-chain alkyl group having 6 to 8 carbon atoms, wherein said alkyl group includes at least one tertiary or one quaternary carbon atom,
(2B) from about 10 mol % to about 20 mol % of vinyl ether represented by formula CH 2 ═CR 3 —OR 4 , wherein R 3 is hydrogen, R 4 is an unsubstituted straight-chain alkyl group having 1 to 3 carbon atoms, and
(3) from about 3 mol % to about 30 mol % of hydroxyalkyl vinyl ether represented by the formula CH 2 ═CR 3 —O—R 5 —OH, where R 3 is hydrogen and R 5 is a C2 to C12 unsubstituted straight-chain, branched-chain or alicyclic alkyl group; and
(ii) a carrier for said one or more fluorocopolymers, wherein said carrier comprises volatile organic compounds (VOCs),
wherein said coating composition comprises: (a) at least about 70% by weight of said one or more fluorocopolymers; (b) not greater than about 30% by weight of said carrier; (c) a volatile organic compound content of less than about 400 g/l; and (d) a viscosity of less than about 1900 mPa·s as measured by Ford Cup of at least 12 revolutions per minute (r/m).
2. The coating composition of claim 1 wherein said one or more fluorocopolymers have a number average molecular weight of from about 10,000 to about 14,000.
3. The coating composition of claim 1 wherein R 5 is a C2 to C12 unsubstituted straight-chain alkyl group.
4. The coating composition of claim 1 wherein R 5 is a C3 to C5 unsubstituted straight-chain, branched-chain or alicyclic alkyl group.
5. The coating composition of claim 4 wherein R 5 is a C3 to C5 unsubstituted straight-chain alkyl group.
6. The coating composition of claim 1 wherein the carrier comprises butyl acetate.
7. The coating composition of claim 1 wherein the carrier comprises a C2-C5 alkyl acetate.