Hyperbranched polymeric dispersants and non-aqueous pigment dispersions
View Patent ↗A polymeric dispersant having a hyperbranched polyurethane architecture obtained by reacting a polyisocyanate core with a mixture of: a) 40 to 65 mol % of an anchor represented by Formula (I) and/or (II): wherein n represents an integer selected from 0 to 7; and X and Y each independently represent a primary amine group or a hydroxyl group; b) 5 to 25 mol % of a polypropylene oxide crosslinker; c) 15 to 40 mol % of a polypropylene oxide graft; and wherein the amount of the crosslinker and the graft taken together is at least 35 mol %; and wherein 100 mol % of the mixture corresponds with the total amount of isocyanate groups in the polyisocyanate core.
1. A polymeric dispersant having a hyperbranched polyurethane architecture obtained by reacting a polyisocyanate core with a mixture of:
a) 40 to 65 mol % of an anchor represented by Formula (I) and/or (II):
wherein n represents an integer selected from 0 to 7; and
X and Y each independently represent a primary amine group or a hydroxyl group;
b) 5 to 25 mol % of a polypropylene oxide crosslinker; and
c) 15 to 40 mol % of a polypropylene oxide graft; wherein
the amount of the crosslinker and the graft taken together is at least 35 mol %; and
100 mol % of the mixture corresponds with a total amount of isocyanate groups in the polyisocyanate core.
2. The polymeric dispersant according to claim 1 , wherein the mixture includes 50 to 60 mol % of the anchor.
3. The polymeric dispersant according to claim 1 , wherein the mixture includes 15 to 25 mol % of the polypropylene oxide crosslinker.
4. The polymeric dispersant according to claim 2 , wherein the mixture includes 15 to 25 mol % of the polypropylene oxide crosslinker.
5. The polymeric dispersant according to claim 1 , wherein the mixture includes 25 to 35 mol % of the polypropylene oxide graft.
6. The polymeric dispersant according to claim 2 , wherein the mixture includes 25 to 35 mol % of the polypropylene oxide graft.
7. The polymeric dispersant according to claim 1 , wherein the polypropylene oxide crosslinker has an average numerical molecular weight M n between 400 and 2,500.
8. The polymeric dispersant according to claim 1 , wherein the polypropylene oxide graft has an average numerical molecular weight M n between 500 and 5,000.
9. The polymeric dispersant according to claim 1 , wherein the polymeric dispersant has an average numerical molecular weight M n of less than 25,000.
10. A non-aqueous pigment dispersion comprising:
a pigment;
a non-aqueous dispersion medium; and
the polymeric dispersant according to claim 1 .
11. A non-aqueous pigment dispersion comprising:
a pigment;
a non-aqueous dispersion medium; and
the polymeric dispersant according to claim 1 ; wherein
the non-aqueous dispersion medium is a radiation curable liquid which is curable by UV-radiation or e-beam.
12. An inkjet ink comprising:
the non-aqueous pigment dispersion according to claim 10 .
13. An inkjet ink comprising:
the non-aqueous pigment dispersion according to claim 11 .
14. An inkjet ink set comprising:
at least two inkjet inks according to claim 12 .
15. A method for preparing a non-aqueous pigment dispersion comprising the steps:
a) providing a polymeric dispersant according to claim 1 ; and
b) dispersing a pigment in the presence of the polymeric dispersant in a non-aqueous dispersion medium.
16. The method according to claim 15 , wherein the non-aqueous dispersion medium is a radiation curable liquid which is curable by UV-radiation or e-beam.
17. The method according to claim 15 , wherein the pigment dispersion is an inkjet ink.
18. An inkjet printing method comprising the steps:
a) providing an inkjet ink including a pigment, a non-aqueous dispersion medium, and the polymeric dispersant according to claim 1 ; and
b) jetting the inkjet ink onto an ink-receiver.
19. The inkjet printing method according to claim 18 , wherein the non-aqueous dispersion medium is a radiation curable liquid which is curable by UV-radiation or e-beam.