US 12,331,209 B2
Inkjet ink set, inkjet recording apparatus, and inkjet recording method
Akinori Koyama, Osaka (JP)
Assigned to KYOCERA Document Solutions Inc., Osaka (JP)
Filed by KYOCERA Document Solutions Inc., Osaka (JP)
Filed on Feb. 23, 2023, as Appl. No. 18/173,674.
Prior Publication US 2024/0287340 A1, Aug. 29, 2024
Int. Cl. B41J 2/21 (2006.01); C09D 11/322 (2014.01); C09D 11/38 (2014.01); C09D 11/40 (2014.01)
CPC C09D 11/40 (2013.01) [B41J 2/2114 (2013.01); B41J 2/2117 (2013.01); C09D 11/322 (2013.01); C09D 11/38 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An inkjet ink set comprising:
a white ink; and
a nonwhite ink, wherein
the white ink contains a white pigment, a first polysaccharide, glycol ether, and water,
the nonwhite ink contains a nonwhite pigment, a second polysaccharide, and water,
the white ink has a first surface tension at 25° C. of no greater than 30 mN/m,
the first surface tension at 25° C. of the white ink and a second surface tension at 25° C. of the nonwhite ink satisfy formula (1),
the white ink has a first viscosity at 25° C. of no greater than 5.0 mPa·s, and
the first viscosity at 25° C. of the white ink and a second viscosity at 25° C. of the nonwhite ink satisfy formula (2):
3 mN/m≤Tc−Tw≤10 mN/m  (1)
3.0 mPa·s≤Vc−Vw≤6.0 mPa·s  (2)
where in the formula (1), Tw represents the first surface tension at 25° C. of the white ink and Tc represents the second surface tension at 25° C. of the nonwhite ink, and
in the formula (2), Vw represents the first viscosity at 25° C. of the white ink and Vc represents the second viscosity at 25° C. of the nonwhite ink.