Aqueous ink jet ink composition
An aqueous ink jet ink is made by forming a mixture of a pigment, an optional dispersant if the pigment is not self-dispersing, dispersing, and a urethane polymer or prepolymer dispersion in water. This ink is useful in a variety of ink jet printing applications such as printing on wide format substrates and textiles.
1. An aqueous ink jet ink composition comprising a dispersed pigment, a polyurethane resin dispersion, and if the dispersed pigment is other than a self-dispersible pigment a dispersant to aid in the dispersion of the pigment;
wherein said polyurethane resin dispersion is derived from reacting a polyisocyanate comprising a diisocyanate of formula
O═C═N—R—N═C═O
with an active-hydrogen containing compound to form a urethane polymer or prepolymer, which is subsequently dispersed into an aqueous media forming a polyurethane resin dispersion;
wherein at least 60% by weight of the polyisocyanate component incorporated into said polyurethane resin dispersion is characterized as an cycloaliphatic isocyanate because the R group includes only aliphatic moieties of 4 to 30 carbon atoms; and
wherein at least 75 mole percent of said active-hydrogen containing compound comprises a polyester from 1,6-hexane diol, neopentyl glycol and adipic acid.
2. An aqueous ink jet ink composition of claim 1 , wherein said diisocyanate of formula O═C═N—R—═C═O is chosen from the group consisting of H12 MDI and IPDI.
3. An aqueous ink jet ink composition of claim 1 , wherein at least 85% of the diisocyanate is chosen from the group consisting of H12 MDI, IPDI, and mixtures thereof.
4. An aqueous ink jet ink composition of claim 1 , wherein at least 85% of the diisocyanate is chosen from the group consisting of H12 MDI.
5. An aqueous ink jet ink composition of claim 1 , wherein said polyester characterized as the polyester from 1,6-hexane diol, neopentyl glycol and adipic acid is characterized by a number average molecular weight of 500 to 10,000 Daltons.
6. An aqueous ink jet ink composition of claim 1 , wherein at least 85 mole % of the active hydrogen containing compound used to form the urethane is a polyester from 1,6-hexane diol and neopentyl glycol reacted with adipic acid.
7. An aqueous ink jet ink composition of claim 1 , wherein the polyurethane resin is chain extended with a di-functional or higher amine with solubility in the continuous water phase of at least 20 grams per liter.
8. An aqueous ink jet ink composition of claim 7 wherein said di-functional amine or higher amine selected from the group consisting of:
a) alkylene diamines
b) hydrazine
c) amino ethanol amines and
d) mixtures thereof.
9. An ink jet printed image on a photograph, rolled textile product or garment wherein the image is generated with ink jet comprising an aqueous ink jet ink composition according to claim 1 .
10. An ink jet printed image on a synthetic polymer in the form of a film, woven or nonwoven substrate wherein the image was generated by digitally jetting an ink jet ink composition according to claim 1 .
11. An ink jet printed image on advertising in the form of a banner, sign, billboard, or point of purchase advertising wherein the image was generated by digitally jetting an ink jet composition ink according to claim 1 .
12. An ink jet ink composition according to claim 1 , wherein said pigment or dye is from 2 to 10 wt. % of said composition, said polyurethane or urethane prepolymer is from 5 to 30 wt. % of said composition, and water is from 20 to 70 wt. % of said composition.