摘要 |
An ink composition includes colorant, hydroxylated and non-hydroxylated co-solvents, and water. A weight percent ratio of hydroxylated to non-hydroxylated co-solvents ranges from 46:54 to about 62:38. The composition also includes an acid and a polyurethane copolymer binder. The acid is selected from the group consisting of oleic acid, linoleic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, and combinations thereof. The binder is formed from the polymerization of a diisocyanate and at least three diols including a first diol containing a hydrophilic stabilizing group, and a second diol having less than 8 atoms in a backbone chain between two hydroxyl groups. A mole percentage of the second diol is at least 30% of a total mole percentage of diol monomers in the binder. An acid number of the binder ranges from 50 to 75. The composition also includes lithium present in an amount ranging from about 50 to about 400 ppm. |