Aqueous ink-jet inks containing random polyurethanes as binders

1. An aqueous ink-jet ink comprising an aqueous vehicle, a pigment and a random copolymer as a binder, wherein said random copolymer is derived from the polymerization of a diisocyanate with three or more diols including a first diol and a second diol, wherein said first diol contains one or more hydrophilic stabilizing groups, the number of backbone atoms on the chain between the two hydroxyl groups of said second diol is less than 8, and the mole % of said second diol relative to the total diols is at least 30%, said copolymer has a general structure of Formula I:

OCN Q 1 n Q 2 m Q 3 p R 1 —NCO   (I)

wherein the terminal isocyanate groups in said copolymer are capped with a capping agent; each Q 1 , Q 2 and Q 3 is independently

provided that Q 1 , Q 2 and Q 3 contain at least one Formula II, at least one Formula III and at least one Formula IV groups;

each R 1 is C 1 -C 20 alkylene, C 3 -C 20 substituted alkylene, C 3 -C 10 cycloalkylene, C 3 -C 20 substituted cycloalkylene, C 6 -C 40 arylene or C 9 -C 40 substituted arylene from a diisocyanate;

each R 2 is independently C 3 -C 20 substituted alkylene, C 3 -C 20 substituted cycloalkylene or C 9 -C 40 substituted arylene;

each R 3 is independently C 9 -C 20 alkylene, C 2 alkylene substituted by C 1 -C 10 alkyl, C 9 -C 20 alkylene substituted by C 1 -C 10 alkyl or C 6 -C 15 aryl; C 9 -C 40 arylene or C 9 -C 40 arylene substituted by C 1 -C 10 alkyl or C 6 -C 20 aryl, —(R 11 —O—R 10 —O—R 11 )—; or HO—R 3 —OH is a diol incorporating polyether, polyester, polycarbonate, polycarbonate-co-polyester or acrylic;

each R 4 is independently C 1 -C 7 alkylene, C 3 -C 20 alkylene substituted by C 1 -C 10 alkyl of C 6 -C 15 aryl; C 6 -C 40 arylene or C 9 -C 40 arylene substituted by C 1 -C 10 alkyl or C 6 -C 20 aryl, provided that the backbone atoms on R 4 forming a chain linking the two oxygen atoms in Formula IV are less than 8;

n, m and p are integers from 1 to 200;

said capping agent is R 6 R 7 NH;

each R 6 is C 1 -C 20 alkyl;

each R 7 is C 1 -C 20 alkyl;

R 6 and R 7 are taken together with the nitrogen atom to form a cyclic amine or substituted cyclic amine with an O or S atom replacing a C atom on said cyclic amine;

each R 10 is independently C 4 -C 20 alkyl, C 4 -C 20 alkyl substituted by C 1 -C 10 alkyl or C 6 -C 15 aryl; C 9 -C 40 aryl or C 9 -C 40 aryl substituted by C 1 -C 10 alkyl or C 6 -C 20 aryl; and

each R 11 is independently C 1 -C 10 alkyl, C 4 -C 20 alkyl substituted by C 1 -C 10 alkyl or C 6 -C 15 aryl.

2. The ink of claim 1 , wherein R 1 is C 3 -C 20 substituted cycloalkylene.

3. The ink of claim 2 , wherein R 2 is C 3 -C 20 substituted alkylene.

4. The ink of claim 3 , wherein R 3 is —(R 11 —O—R 10 —O—R 11 )—.

5. The ink of claim 4 , wherein R 4 is C 1 -C 7 alkylene.

6. The ink of claim 1 , wherein R 6 and R 7 are taken together with the nitrogen atom to form a substituted cyclic amine with an O or S atom replacing a C atom on said cyclic amine.

7. The ink of claim 1 , wherein R 1 is C 9 -C 40 substituted arylene.

8. The ink of claim 7 , wherein R 2 is C 3 -C 20 substituted alkylene.

9. The ink of claim 8 , wherein R 3 is —(R 11 —O—R 10 —O—R 11 )—.

10. The ink of claim 9 , wherein R 4 is C 1 -C 7 alkylene.

11. The ink of claim 10 , wherein R 6 and R 7 are taken together with the nitrogen atom to form a cyclic amine.

12. The ink of claim 10 , wherein R 6 and R 7 are taken together with the nitrogen atom to form a substituted cyclic amine with an O or S atom replacing a C atom on said cyclic amine.

13. The ink of claim 1 , wherein R 1 is C 3 -C 20 substituted alkylene.

14. The ink of claim 13 , wherein R 2 is C 3 -C 20 substituted alkylene.

15. The ink of claim 14 , wherein R 3 is C 9 -C 20 alkylene or C 2 alkylene substituted by C 1 -C 10 alkyl.

16. The ink of claim 15 , wherein R 6 and R 7 are taken together with the nitrogen atom to form a substituted cyclic amine with an O or S atom replacing a C atom on said cyclic amine.

17. The ink of claim 3 , wherein R 3 is C 9 -C 20 alkylene or C 2 alkylene substituted by C 1 -C 10 alkyl.

18. The ink of claim 17 , wherein R 6 and R 7 are taken together with the nitrogen atom to form a substituted cyclic amine with an O or S atom replacing a C atom on said cyclic amine.