Aqueous hyperbranched macromolecule coating compositions

1. An aqueous ambient temperature crosslinkable coating composition comprising a crosslinkable water-dispersible hyperbranched macromolecule(s) with a PDi less than 60 and a dispersed polymer(s) with a particle size in the range of from 25 to 1000 nm and an acid value below 150 mgKOH/g where the ratio of the crosslinkable hyperbranched macromolecule(s) to the dispersed polymer(s) is in the range of from 90:10 to 25:75 on a solids weight basis, and wherein said composition when drying to form a coating has the following properties at 23±2° C.:

i) an open time of at least 20 minutes at 23±2° C.;

ii) a wet edge time of at least 10 minutes at 23±2° C.;

iii) a tack-free time of ≦15 hours at 23±2° C.;

iv) a dust free time of ≦5 hours at 23±2° C.;

v) 0 to 25% of co-solvent by weight of the composition; and

vi) an equilibrium viscosity of ≦5,000 Pa·s, when measured using any shear rate in the range of from 0.09±0.005 to 90±5 s −1 and an equilibrium viscosity of ≦3,000 Pa·s when measured using any shear rate in the range of from 0.9±0.05 to 90±5 s −1 , and an equilibrium viscosity of ≦1,500 Pa·s when measured using any shear rate in the range of from 9±0.5 to 90±5 s −1 , at any solids content when drying in the range of from 20 to 55% by weight of the composition and at 23±2° C.

wherein said hyperbranched macromolecule(s) has a solution viscosity ≦80 Pa·s, as determined from an 80% by weight solids solution of the crosslinkable hyperbranched macromolecule(s) in at least one of the solvents selected from the group consisting of N-methylpyrrolidone, n-butylglycol and mixtures thereof, using a shear rate of 90±5 s −1 and at 50±2° C.; and

wherein said hyperbranched macromolecule(s) has a solution viscosity ≦100 Pa·s, as determined from a 70% by weight solids solution of the crosslinkable hyperbranched macromolecule(s) in a solvent mixture consisting of:

i) at least one of the solvents selected from the group consisting of N-methylpyrrolidone, n-butylglycol and mixtures thereof;

ii) water and

iii) N,N-dimethylethanolamine;

where i), ii) and iii) are in weight ratios of 20/7/3 respectively, using a shear rate of 90±5 s −1 and at 23±2° C.; and

wherein said dispersed polymer(s) is at least one member of the group consisting of vinyl polymer; polyurethane; polyester; polyether; polyamide; polyepoxide; and polymer hybrids thereof.

2. An aqueous ambient temperature crosslinkable coating composition comprising

i) 3 to 26% of a crosslinkable hyperbranched macromolecule(s) with a PDi less than 60 and crosslinkable oligomer(s) by weight of the composition of which at least 52 wt % is a crosslinkable hyperbranched macromolecule(s) with a PDI less than 60;

ii) 0 to 6.5% of a non-crosslinkable oligomer(s) by weight of the composition;

iii) 10 to 56% of dispersed polymer(s) with a particle size in the range of from 25 to 1000 nm and an acid value below 150 mgKOH/g by weight of the composition;

iv) 0 to 15% of co-solvent by weight of the composition;

v) 5 to 65% of water by weight of the composition;

where i)+ii)+iii)+iv)+v)=100%

wherein said composition when drying to form a coating has the following properties:

i) an open time of at least 20 minutes at 23±2° C.;

ii) a wet edge time of at least 10 minutes at 23±2° C.;

iii) a tack-free time of ≦15 hours at 23±2° C.;

iv) a dust free time of ≦5 hours at 23±2° C.;

v) 0 to 25% of co-solvent by weight of the composition;

vi) an equilibrium viscosity of 5,000 Pa·s, when measured using any shear rate in the range of from 0.09±0.005 to 90±5 s −1 , and an equilibrium viscosity of ≦3,000 Pa·s when measured using any shear rate in the range of from 0.9±0.05 to 90±5 s −1 , and an equilibrium viscosity of ≦1,500 Pa·s when measured using any shear rate in the range of from 9±0.5 to 90±5 s −1 , at any solids content when drying in the range of from 20 to 55% by weight of the composition and at 23±2° C.;

wherein said hyperbranched macromolecule(s) has a solution viscosity ≦80 Pa·s, as determined from an 80% by weight solids solution of the crosslinkable hyperbranched macromolecule(s) in at least one of the solvents selected from the group consisting of N-methylpyrrolidone, n-butylglycol and mixtures thereof, using a shear rate of 90±5 s −1 and at 50±2° C.; and

wherein said hyperbranched macromolecule(s) has a solution viscosity ≦100 Pa·s, as determined from a 70% by weight solids solution of the crosslinkable hyperbranched macromolecule(s) in a solvent mixture consisting of:

i) at least one of the solvents selected from the group consisting of N-methylpyrrolidone, n-butylglycol and mixtures thereof;

ii) water and

iii) N,N-dimethylethanolamine;

where i), ii) and iii) are in weight ratios of 20/7/3 respectively, using a shear rate of 90±5 s −1 and at 23±2° C.; and

wherein said dispersed polymer(s) is at least one member of the group consisting of vinyl polymer; polyurethane; polyester; polyether; polyamide; polyepoxide; and polymer hybrids thereof.

3. An aqueous composition according to claim 1 or claim 2 wherein said composition has an equilibrium viscosity ≦5,000 Pa·s when measured using a shear rate in the range of from 0.09±0.005 to 90±5 s −1 after a 12% increase of the solids content by weight of the composition when drying.

4. An aqueous composition according to claim 1 or claim 2 wherein the crosslinkable hyperbranched macromolecule(s) has a measured weight average molecular weight in the range of from 1,000 to 120,000 Daltons.

5. An aqueous composition according to claim 1 or claim 2 wherein the hyperbranched macromolecule(s) has a measured Tg in the range of from −90 to 100° C.

6. An aqueous composition according to claim 1 or claim 2 wherein the crosslinkable water-dispersible hyperbranched macromolecule(s) is self-crosslinkable.

7. An aqueous composition according to claim 1 or 4 wherein the crosslinkable water-dispersible hyperbranched macromolecule(s) is crosslinkable by autoxidation optionally in combination with Schiff base crosslinking.

8. An aqueous composition according to claim 7 wherein the crosslinkable water-dispersible hyperbranched macromolecule(s) contains autoxidisable groups and carbonyl functional groups.

9. An aqueous composition according to claim 1 or claim 2 wherein the crosslinkable water-dispersible hyperbranched macromolecule(s) is crosslinkable by Schiff base crosslinking optionally in combination with silane condensation.

10. An aqueous composition according to claim 1 or claim 2 wherein the crosslinkable water-dispersible hyperbranched macromolecule(s) is crosslinkable by silane condensation optionally in combination with autoxidation.

11. An aqueous composition according to claim 1 or claim 2 wherein the dispersed polymer(s) has a measured weight average molecular weight ≧130,000 Daltons.

12. An aqueous composition according to claim 1 or claim 2 wherein the dispersed polymer(s) has a measured weight average molecular weight <130,000 Daltons with the proviso that the dispersed polymer(s) has a solution viscosity >150 Pa·s, as determined from a 80% by weight solids solution of the dispersed polymer(s) in at least one of the solvents selected from the group consisting of N-methylpyrrolidone, n-butylglycol and mixtures thereof, using a shear rate of 90±5 s −1 and at 50±2° C.

13. An aqueous composition according to claim 1 or claim 2 wherein the dispersed polymer(s) is a vinyl polymer.

14. An aqueous composition according to claim 1 or claim 2 wherein the dispersed polymer(s) has a measured Tg in the range of from −50 to 300° C.

15. An aqueous coating composition according to claim 1 or claim 2 comprising:

i) 0 to 15% co-solvent by weight of crosslinkable hyperbranched macromolecule(s), crosslinkable oligomer(s), non-crosslinkable oligomer(s) and dispersed polymer(s);

ii) 35 to 65% of crosslinkable hyperbranched macromolecule(s) by weight of crosslinkable hyperbranched macromolecule(s), crosslinkable oligomer(s), non-crosslinkable oligomer(s) and dispersed polymer(s); wherein the crosslinkable hyperbranched macromolecule(s) comprises 45 to 75 wt % of fatty acid groups; and wherein the dispersed polymer(s) has an acid value below 20 mgKOH/g.

16. An aqueous coating composition according to claim 1 or claim 2 comprising:

i) 14 to 40% of a crosslinkable hyperbranched macromolecule(s) and crosslinkable oligomer(s) by weight of crosslinkable hyperbranched macromolecule(s), crosslinkable oligomer(s), non-crosslinkable oligomer(s) and dispersed polymer(s), of which at least 52 wt % is a crosslinkable water-dispersible hyperbranched macromolecule;

ii) 0 to 10% of a non-crosslinkable oligomer(s) by weight of crosslinkable hyperbranched macromolecule(s), crosslinkable oligomer(s), non-crosslinkable oligomer(s) and dispersed polymer(s);

iii) 50 to 85% of dispersed polymer(s) by weight of crosslinkable hyperbranched macromolecule(s), crosslinkable oligomer(s), non-crosslinkable oligomer(s) and dispersed polymer(s);

where i)+ii)+iii)=100%.

17. An aqueous coating composition according to claim 1 or claim 2 additionally comprising a pigment.

18. A coating obtained from an aqueous composition according to claim 1 or claim 2 .

19. An aqueous composition according to claim 1 or claim 2 wherein the dispersed polymer(s) has a measured weight average molecular weight <130,000 Daltons with the proviso that the dispersed polymer(s) has a solution viscosity >150 Pa·s, as determined from a 80% by weight solids solution of the dispersed polymer(s) in at least one of the solvents selected from the group consisting of N-methylpyrrolidone, n-butylglycol and mixtures thereof, using a shear rate of 90±5 s −1 and at 50±2° C. and the crosslinkable hyperbranched macromolecule(s) has a PDi less than 60.