Aqueous copolymer dispersions with reactive diluent
View Patent ↗The present invention relates to aqueous copolymer dispersions containing A) one or more hydroxy-functional copolymers synthesized from a) one or more OH-free (meth)acrylic esters and/or vinylaromatics, b) one or more hydroxy-functional (meth)acrylic esters, c) one or more ionic and/or potential ionic monomers capable of free-radical copolymerization, and d) one or more optionally monomers other than components a) to c) that are capable of free-radical copolymerization, and B) one or more hydroxy-functional polycarbonate polyols as reactive diluent. The present invention also relates to a process for preparing these aqueous copolymer dispersions and to their use in coating compositions.
1. An aqueous copolymer dispersion comprising
A) one or more hydroxy-functional copolymers synthesized from
a) one or more OH-free (meth)acrylic esters and/or vinylaromatics,
b) one or more hydroxy-functional (meth)acrylic esters,
c) one or more ionic and/or potential ionic monomers capable of free-radical copolymerization, and
d) optionally one or more monomers other than components a) to c) that are capable of free-radical copolymerization, and
B) one or more hydroxy-functional polycarbonate polyols having a number average molecular weight of 750 to 1500 as reactive diluent.
2. The aqueous copolymer dispersion of claim 1 wherein hydroxy-functional polycarbonate polyols B) have an average hydroxyl functionality of 1.6 to 6 and a number average molecular weight of 240 to 5000 Da.
3. The aqueous copolymer dispersion of claim 1 wherein hydroxy-functional polycarbonate polyols B) are prepared from 1,4-butanediol, 1,6-hexanediol.3-methyl-1,5-pentanediol or mixtures thereof.
4. The aqueous copolymer dispersion of claim 2 wherein hydroxy-functional polycarbonate polyols B) are prepared from 1,4-butanediol, 1,6-hexanediol. 3-methyl-1,5-pentanediol or mixtures thereof.
5. The aqueous copolymer dispersion of claim 1 wherein hydroxy-functional polycarbonate polyols B) have an average hydroxyl functionality of 1.9 to 2.05.
6. The aqueous copolymer dispersion of claim 2 wherein hydroxy-functional polycarbonate polyols B) have an average hydroxyl functionality of 1.9 to 2.05.
7. The aqueous copolymer dispersion of claim 3 wherein hydroxy-functional polycarbonate polyols B) have an average hydroxyl functionality of 1.9 to 2.05.
8. The aqueous copolymer dispersion of claim 4 wherein hydroxy-functional polycarbonate polyols B) have an average hydroxyl functionality of 1.9 to 2.05.
9. An aqueous coating composition comprising
i) one or more of the aqueous copolymer dispersions of claim 1 and
ii) one or more OH-reactive crosslinkers.
10. A process for producing coatings which comprises applying a coating composition comprising the copolymer dispersion of claim 1 to a substrate and subsequently curing the coating composition to form a coating.
11. A substrate coated with the coating composition of claim 1 .