Amino acid derivatives and their use as a sag control agent

1. A coating composition comprising:

i) a binder, and

ii) a rheology modification agent obtained by reacting one or more polyisocyanates with one or more optically active amino acid esters of the general formula (I)

not as racemic mixture;

wherein each of R 1 and R 2 is independently selected from the group consisting of hydrogen and a hydrocarbyl group, wherein the hydrocarbyl group is linear or cyclic or branched, substituted or unsubstituted, saturated or unsaturated, and optionally containing a heteroatom, with each of R 1 and R 2 being different such that the carbon atom C* is a chiral centre; and

wherein R 3 is a hydrocarbyl group, wherein the hydrocarbyl group is linear or cyclic or branched, substituted or unsubstituted, saturated or unsaturated, and optionally containing a heteroatom.

2. A coating composition according to claim 1 wherein the one or more polyisocyanates are selected from the group consisting of: substituted or unsubstituted linear aliphatic polyisocyanates with an even number of carbon atoms in the chain between two isocyanate groups; dimers, trimers or biurets thereof substituted or unsubstituted arylene polyisocyanates; substituted or unsubstituted aralkylene polyisocyanates; and substituted or unsubstituted cyclohexylene polyisocyanates.

3. A coating composition according to claim 1 wherein the one or more optically active amino acid esters of formula (I) are esters of amino acids selected from the group of compounds consisting of:

4. A coating composition according to claim 1 wherein R 1 and/or R 2 is a hydrocarbyl group, wherein the hydrocarbyl group is independently linear or cyclic or branched, substituted or unsubstituted, saturated or unsaturated, and optionally containing a heteroatom.

5. A coating composition according to claim 1 wherein R 1 and/or R 2 is a hydrocarbyl group independently selected from the group consisting of a linear or branched C 1 -C 24 alkyl group, a linear or branched C 1 -C 4 alkyl group, a methyl group, and an ethyl group.

6. A coating composition according to claim 1 wherein R 3 is a linear, cyclic or branched C 1-25 hydrocarbyl group selected from the group consisting of an alkyl group, an aryl group, an aralkyl group, and an alkenyl group; wherein said hydrocarbyl group is substituted or unsubstituted, saturated or unsaturated, and optionally containing a heteroatom.

7. A coating composition according to claim 1 wherein R 3 is a linear or branched C 1 -C 25 alkyl group; wherein said hydrocarbyl group is substituted or unsubstituted, and optionally containing a heteroatom.

8. A coating composition according to claim 1 wherein R 3 is a linear or branched C 1 -C 8 hydrocarbyl group selected from the group consisting of an alkyl group, an ether group, and an optionally esterified (poly)alkoxy group; wherein said hydrocarbyl group is substituted or unsubstituted.

9. A coating composition according to claim 1 wherein R 3 is a linear C 1 -C 4 hydrocarbyl group selected from the group consisting of an alkyl group and an optionally alkoxylated alkoxy group.

10. A coating composition according to claim 1 wherein the coating composition is an isocyanate based coating composition.

11. A coating composition according to claim 1 wherein the coating composition is an acryloyl based coating composition.

12. A coating composition according to claim 1 wherein the coating composition is an epoxy curable coating composition.

13. A coating composition according to claim 1 wherein the coating composition is a dual curable coating composition.

14. A coating composition according to claim 1 wherein the coating composition is a isocyanate-reactive two-component (2K) coating system that is cured with one or more polyol compounds, thiol compounds, amine-functional compounds, or combinations thereof, at a temperature of at least 25° C. and below 150° C.