Carbon black pigmented inkjet ink having multiple humectants
View Patent ↗The present invention relates to a carbon black inkjet ink having improved printhead idle time and start up in order to substantially maintain, un-interrupted printing with better nozzle jetting. The inkjet ink includes a non-ionic silicone surfactant, a polymeric dispersant, and two or more humectants.
1. An inkjet ink comprising:
a carbon black pigment dispersion;
a non-ionic silicone surfactant being about 0.1% to about 1.2% by weight of the inkjet ink;
a polymeric dispersant being about 0.5% to about 1.5% by weight of the inkjet ink, the polymeric dispersant comprising a ter-polymer having moieties of methacrylic acid (MAA), poly(propylene glycol)-4-nonylphenyl ether acrylate (NPHPPG), and poly(ethylene glycol)2,4,6-tris-(1-phenylethyl)phenyl ether methacrylate (TRISA); and
two or more humectants being about 20% to about 21% by weight of the inkjet ink and selected from the group consisting of 1,2-hexanediol; 1,3-propanediol; glycerol; and tri-ethylene glycol.
2. The inkjet ink according to claim 1 , wherein the non-ionic silicone surfactant is a polyalkylene oxide polysiloxane having a dimethyl polysiloxane hydrophobic moiety and one or more hydrophilic polyalkylene side chains.
3. The inkjet ink according to claim 1 , wherein the non-ionic silicone surfactant has a molecular weight of about 4000.
4. The inkjet ink according to claim 1 , wherein the non-ionic silicone surfactant being about 0.5% to about 0.8% by weight of the inkjet ink.
5. The inkjet ink according to claim 1 , wherein a molar ratio of MAA in the polymeric dispersant is about 15 parts to about 2 parts of a combination of NPHPPG and TRISA, and a molar ratio of TRISA in the polymeric dispersant is about 1 part to about 16 parts of a combination of NPHPPG and MAA.
6. The inkjet ink according to claim 1 , further comprising a biocide and water.
7. A method of printing using an inkjet ink, the method being comprised of the steps of:
positioning a print medium substantially adjacent to a printer having a print head retaining an inkjet ink, wherein the inkjet ink is comprised of
a carbon black pigment dispersion;
a non-ionic silicone surfactant being about 0.1% to about 1.2% by weight of the inkjet ink;
a polymeric dispersant being about 0.5% to about 1.5% by weight of the inkjet ink, the polymeric dispersant comprising a ter-polymer having moieties of methacrylic acid (MAA), poly(propylene glycol)-4-nonylphenyl ether acrylate (NPHPPG), and poly(ethylene glycol)2,4,6-tris-(1-phenylethyl)phenyl ether methacrylate (TRISA); and
two or more humectants being about 20% to about 21% by weight of the inkjet ink and selected from the group consisting of 1,2-hexanediol; 1,3-propanediol; glycerol; and tri-ethylene glycol; and
jetting the inkjet ink from the print head onto the print medium as directed by the printer.
8. The method according to claim 7 , wherein the non-ionic silicone surfactant is a polyalkylene oxide polysiloxane having a dimethyl polysiloxane hydrophobic moiety and one or more hydrophilic polyalkylene side chain.
9. The method according to claim 7 , wherein the non-ionic silicone surfactant has a molecular weight of about 4000.
10. The method according to claim 7 , wherein the non-ionic silicone surfactant being about 0.5% to about 0.8% by weight of the inkjet ink.
11. The method according to claim 7 , wherein a molar ratio of MAA in the polymeric dispersant is about 15 parts to about 2 parts of a combination of NPHPPG and TRISA, and a molar ratio of TRISA in the polymeric dispersant is about 1 part to about 16 parts of a combination of NPHPPG and MAA.
12. The method according to claim 7 , further comprising a biocide and water.